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Question 2..On MRI, what nerve is most likely to demonstrate increased signal intensity about the elbow in asymptomatic patients?

1- Ulnar 2- Radial 3- Median 4- Anterior interosseous 5- Musculocutaneous DISCUSSION: The ulnar nerve has been shown to have increased signal intensity in asymptomatic patients when compared with other nerves about the elbow. It has been shown to have increased signal in approximately 60% of normal patients compared with 0% for the median and radial nerves. This suggests that the presence of increased signal in the ulnar nerve may be of questionable clinical relevance.Pre Res# 2 is 1.

Question 3Figure 3 shows an arthroscopic view of the radiocarpal joint from the 3-4 portal, looking volarly and radially (Sc=scaphoid, R=Radius). What structure is marked by the asterisk?

1. Radioscaphocapitate ligament

2. Scapholunate ligament 3- Palmar oblique ligament

4. Dorsal intercarpal ligament

5. Triangular fibrocartilage complex (TFCC)

 

DISCUSSION: The radioscaphocapitate ligament is a volar capsular structure running obliquely from the radial styloid to the scaphoid waist, ultimately inserting on the proximal radial aspect of the capitate. The radioscaphocapitate ligament is important in preventing ulnar translocation of the carpus. The scapholunate ligament is located intra-articularly, between the scaphoid and lunate. The dorsal intercarpal ligament is a dorsal structure, and not visible during routine wrist arthroscopy. The palmar oblique ligament connects the first and second metacarpal bases. The TFCC is visible during wrist arthroscopy between the radius and ulna. Preferred Response # 3 is 1.

 

Question 4A 15-year-old boy sustained an anterior sternoclavicular joint dislocation. What is the preferred management?

1- Open reduction and internal fixation 2- Observation

3. Closed reduction

4. Closed reduction and percutaneous pinning 5- Figure-of-8 brace

 

DISCUSSION: The medial clavicular epiphysis is the last to fuse (age 22 to 25 in men) and sternoclavicular injuries are often Salter-Harris type II fractures in this age group, with opportunity to remodel. Closed reduction is generally not necessary and has a high recurrence rate. Closed reduction is necessary with posterior dislocations associated with compression of the trachea, esophagus, or great vessels. Figure-of-8 bracing has not been shown to secure a sternoclavicular reduction. Pre Resp# 4 is 2.

 

Question 5A 22-year-old man reports a 2-week history of a burning pain along the dorsoradial aspect of the distal forearm. The pain radiates to the dorsum of the thumb. Examination reveals tenderness and reproduction of symptoms with percussion 8 cm proximal to the radial styloid. Reproduction of symptoms also occurs with forearm pronation and ulnar deviation of the wrist. No discrete sensory deficit is noted and electrodiagnostic studies are normal. Nonsurgical management consisting of rest, splinting, and anti-inflammatory medications for 6 weeks has failed to provide relief. Treatment should now consist of decompression of the

 

1. lateral antebrachial cutaneous nerve in the interval between the abductor pollicis longus and the extensor pollicis brevis in the forearm.

2. lateral antebrachial cutaneous nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.

3. radial sensory nerve in the interval between the extensor carpi radialis longus and the extensor carpi radialis brevis in the distal forearm.

4. radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm.

5. radial sensory nerve in the interval between the brachioradialis and the extensor carpi radialis brevis in the distal forearm.

 

DISCUSSION: Wartenberg's syndrome, or compression of the sensory branch of the radial nerve, occurs in the interval between the brachioradialis and the extensor carpi radialis longus approximately 8 cm proximal to the radial styloid. There may be history of repetitive wrist/forearm circumduction activity (ie, knitting) or of wearing a tight wristwatch or jewelry. It can occur in patients who have been handcuffed. Typical clinical findings are pain, paresthesia, and/or hypesthesia in the dorsoradial aspect of the wrist and hand in the distribution of the radial sensory nerve. There is often a positive Tinel's sign over the compression site. Hypesthesia may be present in the distribution of the radial sensory nerve which is typically on the dorsal aspect of the first dorsal web space and dorsum of the thumb; however, with overlap in the distribution of the superficial radial nerve and the lateral cutaneous nerve of the forearm this may not always be present. Surgical management consists of release of the nerve as it exits the interval between the brachioradialis and the extensor carpi radialis longus in the distal forearm. The Preferred Response to Question # 5 is 4.

Question 6A patient has multidirectional instability of the shoulder that has not responded to nonsurgical management. Successful surgical treatment will most likely include which of the following?

1. Abrasion arthroplasty of the anterior glenoid rim

2. Posterior capsular advancement into a Hill-Sachs defect 3- Repair of an inferior glenohumeral ligament detachment 4- Repair of an unstable SLAP tear

5- Closure of the rotator interval

 

DISCUSSION: Published reports establish the importance of the rotator interval in shoulder stability and improvements achieved through suture closure of the interval. Multidirectional instability treated surgically following failure to respond to nonsurgical management has been shown to be associated with classic Bankart lesions, Hill-Sachs defects, glenoid chondral lesions, and even SLAP lesions (Werner). However, these lesions were seen in a lower percentage than that found for unidirectional anterior dislocations. Likewise, these lesions do not appear to be significant in influencing treatment in the majority of patients. The Preferred Response to Question # 6 is 5.

 

Question 7An active 65-year-old man has pain in the left shoulder 5 years after undergoing a hemiarthroplasty. He has a remote history of two previous instability operations. Examination reveals that forward elevation is 140 degrees and external rotation is 40 degrees. Serologic studies for infection are negative. AP and axillary radiographs are shown in Figures 7a and 7b. What surgical procedure will provide the most predictable pain relief and function?

1- Conversion to a reverse total shoulder arthroplasty 2- Conversion to a standard total shoulder arthroplasty 3- Conversion to a glenohumeral fusion

4. Resection arthroplasty

5. Biologic resurfacing of the glenoid

 

DISCUSSION: The radiographs show glenoid arthrosis, which is common after a hemiarthroplasty. Conversion to a conventional total shoulder arthroplasty with placement of a glenoid component predictably decreases pain and improves function. There is no indication for a reverse total shoulder arthroplasty because the patient has 140 degrees of elevation with an intact rotator cuff. Biologic resurfacing has more

 

unpredictable results and is usually reserved for younger patients in whom a prosthetic glenoid component might not be desired. Both resection arthroplasty and arthrodesis are associated with poor function. The Preferred Response to Question # 7 is 2.

 

Question 8A 55-year-old woman with rheumatoid arthritis reports that she awoke with an inability to flex the interphalangeal joint of her thumb. Figure 8 shows an intraoperative finding. What is the most appropriate surgical treatment?

 

1. Primary repair of the tendon

2. Tendon reconstruction with the palmaris longus tendon

3. Tendon reconstruction using a transfer of the flexor digitorum profundus (FDP) of the ring finger

4. Thumb metacarpophalangeal fusion

5. End-to-side repair of the flexor pollicis longus to the FDP of the index finger

 

DISCUSSION: The patient has sustained a chronic flexor pollicis longus rupture (Mannerfelt lesion). The injury is most likely a result of tendinopathy and attritional rupture of the tendon secondary to synovitis and bony osteophytosis at the scaphotrapeziotrapezoid joint. Because of the attritional injury and inherent tendinopathy, primary repair is unlikely to be successful. Among the options listed, tendon graft reconstruction with the palmaris longus tendon is the most appropriate treatment. Tendon reconstruction is possible with the flexor digitorum profundus of the index finger, not the flexor digitorum profundus of the ring finger. If osteophytes are encountered, these should be debrided. Thumb interphalangeal fusion is an option, but metacarpophalangeal fusion is not beneficial. End-to-side repair of the flexor pollicis longus to the FDP of the index finger is not appropriate and would sacrifice needed function of the index finger. Preferred Response to Question # 8 is 2.

 

Question 9A 56-year-old man who tripped and fell out of his golf cart onto his right shoulder 4 days ago now reports mild pain while chipping. Examination reveals mild bruising over the lateral clavicle but good shoulder range of motion and strength. A radiograph is shown in Figure 9. Appropriate treatment at this time should include which of the following?

1. Intramedullary pinning

2. Bone stimulator

3. Sling for comfort, followed by gentle range-of-motion exercises 4- Open reduction and internal fixation with a plate and screws

5- Arthroscopic distal clavicle resection

 

DISCUSSION: Treatment of this minimally displaced distal clavicle fracture should begin with nonsurgical management consisting of sling therapy followed by gentle motion therapy. Any form of surgical intervention at this time is unnecessary because this fracture pattern has a high incidence of union. A bone stimulator may be used if healing becomes delayed. The Preferred Response to Question # 9 is 3.

 

10,Atraumatic suprascapular nerve compression usually occurs at which of the following anatomic locations if it develops atraumatically?

1. Scalenus anterior

2. Suprascapular and spinoglenoid notches 3- Cervical rib

4. Conjoined tendon

5. Subcoracoid

 

DISCUSSION: The suprascapular nerve has the potential to be compressed as it passes through the suprascapular and spinoglenoid notches. If the site of compression occurs at the suprascapular notch, both the supraspinatus and infraspinatus muscles will be affected. If the site of compression occurs at the spinoglenoid notch, only the infraspinatus muscle will be affected. Fascial bands and ganglion cysts often compress the nerve in these areas. The other anatomic areas are not associated with suprascapular nerve compression. The Preferred Response to Question # 10 is 2.

 

11..Which of the following 50-year-old patients with an irreparable rotator cuff tendon is the best candidate for an isolated latissimus dorsi muscle transfer?

1. Man with active elevation to 90 degrees

2. Woman with active elevation to 45 degrees

3. Woman with a Hornblower's sign (complete absence of external rotation with abduction)

4. Man with superior escape of the humeral head 5- Man with full motion and a positive lift-off test

 

DISCUSSION: Patients with superior escape or a torn subscapularis (demonstrated by a positive lift-off test) will not benefit from a latissimus dorsi transfer, even if combined with a pectoralis muscle transfer. In the study by Iannotti and associates, women had poorer outcomes than men, and patients with preoperative elevation below shoulder level or 90 degrees also had poorer outcomes. Patients with complete loss of external rotator function have worse function after latissimus dorsi transfer than patients with some external rotation function. The Preferred Response to Question # 11 is 1.

 

12.Figures 12a and 12b show the initial radiographs of a 27-year-old snow boarder who fell backward onto his left outstretched hand. Which of the following most accurately describes the sequence of events that occurred during this injury?

1. Lunotriquetral ligament failure followed by distal row dissociation, scaphoid extension, scaphoid failure, and dorsal dislocation of the carpus

2. Volar dislocation of the lunate followed by scaphoid extension, scaphoid failure, lunotriquetral failure, and distal row dissociation

3. Dorsal intercarpal ligament failure followed by distal row dissociation, scaphoid failure, lunotriquetral ligament failure, and dorsal dislocation of the carpus

 

4. Short radiolunate ligament failure followed by volar dislocation of the lunate, lunotriquetral ligament failure, scaphoid failure, and distal row dissociation

5. Scaphoid extension followed by scaphoid failure, distal row dissociation, lunotriquetral ligament failure, and dorsal dislocation of the carpus

 

DISCUSSION: As described by Mayfield and associates, the typical sequence of events referred to as "progressive perilunar instability" that result in a volar perilunate dislocation are as follows: scaphoid extension, followed by opening of the space of Poirer, scaphoid failure, and distal row dissociation, which in turn lead to hyperextension of the triquetrum, lunotriquetral ligament failure, and finally dorsal dislocation of the carpus. The lunate remains in the lunate fossa in a perilunate fracture-dislocation but is dislocated in a lunate dislocation. The short radiolunate and dorsal intercarpal ligaments typically remain intact. Preferred Response # 12 is 5.

 

13..One week ago a 25-year-old man slipped on the ice and fell, catching himself on a railing. He sustained an anterior shoulder dislocation that was subsequently reduced without difficulty in the emergency department, and he was discharged in a sling. He is now back for follow-up and reports no pain. Examination reveals no weakness on external rotation strength testing. What is the most appropriate management for this patient?

1. Arthroscopic Bankart repair

2. MRI for possible rotator cuff tear 3- Physical therapy

4- Sling immobilization for an additional 2 weeks 5- Cortisone injection

 

DISCUSSION: On the basis of the patient's age, lack of weakness, and the fact that this is a first-time traumatic shoulder dislocation, he is unlikely to have sustained a rotator cuff tear. Immobilization should be continued for 2 more weeks. Scheduling a surgical stabilization procedure at this time is not indicated. Immediate therapy is contraindicated because of the acuity of the injury. A cortisone injection is not indicated in an acute traumatic shoulder dislocation. Preferred Response # 13 is 4.

 

14..A 75-year-old woman who is right-hand dominant fell from a 2-foot step and landed on her outstretched right arm, sustaining an injury to the elbow. She reports no other injuries and is in generally good health. Examination reveals a swollen, ecchymotic elbow and intact skin, with a normal distal neurovascular examination. Radiographs are shown in Figures 14a and 14b. Management of the injury should include which of the following?

1. Total elbow arthroplasty

2. Spanning articulated external fixation 3- Long arm cast for 2 weeks, followed by progressive mobilization

4. Open reduction and internal fixation

5. Closed reduction and percutaneous screw fixation

 

DISCUSSION: The patient sustained a displaced, comminuted, intercondylar distal humerus fracture. In an otherwise healthy patient older than age 65 years,

randomized clinical trials have demonstrated more predictable outcomes with total elbow arthroplasty when compared with open reduction and internal fixation. Closed reduction and percutaneous fixation is biomechanically inadequate to maintain fracture alignment and allow early mobilization. Spanning external fixation is typically used to maintain stability in the setting of a complex elbow fracture-dislocation.

Nonsurgical management would be considered when a patient is medically unfit for surgery. The Preferred Response to Question # 14 is 1.

 

15Which of the following is the most consistently proposed tendon transfer for radial nerve palsy?

1- Pronator teres to extensor carpi radialis brevis 2- Brachioradialis to extensor carpi radialis brevis

3- Flexor carpi radialis to extensor digitorum communis 4- Palmaris longus to extensor pollicis longus

5- Flexor digitorum superficialis to abductor pollicis longus and extensor pollicis brevis

 

DISCUSSION: Whereas there are many variations of tendon transfers for radial nerve palsy, the most consistently proposed tendon transfer is the pronator teres to extensor carpi radialis brevis. The brachioradialis is innervated by the radial nerve so that is not an option. The flexor digitorum superficialis, flexor carpi radialis, and flexor carpi ulnaris are appropriate options to transfer to the extensor digitorum communis. The palmaris longus is not always present. A transfer to the abductor pollicis longus and extensor pollicis brevis may not be necessary if the extensor pollicis longus is rerouted to allow for abduction of the first ray. The Preferred Response to Question # 15 is 1.

 

16..A 20-year-old man has activity-related deep-seated shoulder pain in his dominant right shoulder. He has taken 3 months off training as a college javelin thrower, and management consisting of physical therapy has failed to provide relief. Shoulder arthroscopic views are shown in Figures 16a through 16c. What is the underlying association with this condition?

 

1. Ehlers-Danlos syndrome

2. Traumatic anterior instability 3- Humeral head osteonecrosis 4- Internal impingement

5- Partial-thickness supraspinatus tear

 

DISCUSSION: The patient is involved in overhead athletics and reports deep-seated pain. The arthroscopic views show a SLAP tear with posterior extension that is typical of internal impingement. The history lacks a component of gross instability expected in traumatic anterior dislocations or multidirectional instability associated with a connective tissue disorder, and it also lacks risk factors for osteonecrosis. The images do not show evidence of an unstable humeral cartilage flap or a supraspinatus tear.

The Preferred Response to Question # 16 is 4.

 

17.Figure 17 shows the radiograph of an 82-year-old right-hand dominant woman who fell while weeding her garden. She has severe right shoulder pain. She is neurovascularly intact. What is the most appropriate treatment?

1. Rest, ice, nonsteroidal anti-inflammatory drugs, activity as tolerated, and follow- up in 4 weeks

2. Coaptation splinting and follow-up in 4 weeks

3. Surgical replacement with hemiarthroplasty or reverse total shoulder arthroplasty 4- Physical therapy for range-of-motion exercises

5- Closed reduction, splinting, and follow-up in 4 weeks

 

DISCUSSION: The patient has a displaced four-part proximal humerus fracture. The humeral head is displaced and if allowed to heal in this position, the patient will likely have a stiff and painful shoulder. The humerus is at risk for osteonecrosis given the displacement of the fracture. Given a patient age of 82 years, replacement options of either hemiarthroplasty or reverse total shoulder arthoplasty, allow maximal restoration of function. Physical therapy is not indicated in this acute fracture. Closed reduction techniques will not be successful in this displaced fracture. Preferred Response to Question # 17 is 3.

 

18..During the Kocher approach to repair a radial head fracture, care must be taken not to release what posterior structure lying under the anconeus that may be inadvertently injured during this common lateral approach to the elbow?

1. Ulnar nerve

2. Annular ligament

3. Anterior band of the medial collateral ligament 4- Lateral ulnar collateral ligament

5- Arcade of Struthers

 

DISCUSSION: The lateral ulnar collateral ligament may be iatrogenically injured during dissection through the internervous plane between the extensor carpi ulnaris and anconeus (Kocher approach). Dissection posteriorly may compromise this ligament, leading to pain and rotatory instability of the elbow. The ulnar nerve, annular ligament, medial collateral ligament, and arcade of Struthers are not anatomically in this area.

The Preferred Response to Question # 18 is 4.

 

19A 27-year-old man has recurrent anterior shoulder instability following an arthroscopic Bankart repair 4 years ago. Current CT scans are shown in Figures 19a and 19b. Deficiency of what mechanism is most likely to contribute to the current joint instability?

 

1- Synovial fluid adhesion-cohesion 2- Negative intra-articular pressure

3. Concavity-compression of the humeral head in the glenoid

4. Decreased functional arc of motion as a result of a Hill-Sachs lesion 5- Poor rehabilitation of scapulothoracic rhythm

 

DISCUSSION: Loss of the anterior glenoid rim can commonly occur as a result of acute fracture or progressive wear following multiple dislocations. This decreases the effective depth of the glenoid. The ability of the rotator cuff to stabilize the joint through production of a joint reactive force is markedly decreased. Synovial fluid adhesion-cohesion and negative intra-articular pressure are maintained in the closed capsular space. The Hill-Sachs lesion in this case is not large enough to be a significant factor in failed Bankart repair. Poor scapulothoracic rhythm can increase the risk of instability but is not typically the primary factor. The Preferred Response # 19 is 3.

 

20..A 48-year-old man undergoes arthroscopy to repair a rotator cuff tear. During the arthroscopy, the tear is characterized and found to involve the entire supraspinatus and a majority of the infraspinatus tendons. After mobilization, the posterior rotator cuff can reach the greater tuberosity. However, the supraspinatus tendon cannot reach its insertion point at the greater tuberosity. What is the most appropriate treatment?

 

1- Conversion to a latissimus dorsi muscle tendon transfer 2- Acromioplasty and coracoacromial ligament release

3- Reverse acromioplasty (tuberoplasty) 4- Reverse total shoulder arthroplasty

5- Partial repair of the rotator cuff

 

DISCUSSION: If a complete rotator cuff repair is not possible, a partial rotator cuff repair should still be considered and is the appropriate treatment for this patient. In patients with an irreparable massive rotator cuff tear, acromioplasty with coracoacromial ligament release, reverse acromioplasty, and tenotomy of the biceps tendon may improve shoulder pain. If these procedures fail, then a muscle transfer procedure can also be considered in select patients. If, however, a portion of the rotator cuff can be repaired, even partial repair can balance the coronal and axial forces about the shoulder to restore the kinematics of the joint. Reverse total shoulder arthroplasty is not appropriate for this relatively young patient. The Preferred Response to Question # 20 is 5.

 

21..A 71-year-old woman reports the insidious onset of shoulder pain at night and when moving her shoulder. She cannot raise her arm above shoulder level. Physical therapy has failed to provide pain relief or improve function. An injection relieved her pain in the office, but she could not raise her arm above shoulder level. A radiograph is shown in Figure 21. What surgical procedure will provide the best chance of restoring above shoulder function and pain relief?

1- Reverse total shoulder arthroplasty 2- Hemiarthroplasty of the shoulder

3. Arthroscopic biceps tenolysis

4. Open subacromial debridement 5- Total shoulder arthroplasty

 

DISCUSSION: The radiograph shows complete loss of the

acromiohumeral space. The glenohumeral joint space is also severely narrowed, which is consistent with rotator cuff tear arthropathy. In patients who have pain that limits elevation, pain-reducing procedures such as biceps tenolysis, open debridement, or

 

hemiarthroplasty may allow the patient to regain the shoulder function. If the patient cannot elevate the arm after a successful local anesthetic injection, then pain is not the reason for the patient's loss of elevation. In this situation, a reverse total shoulder arthroplasty will most reliably restore function and provide pain relief. The Preferred Response to Question # 21 is 1.

 

22..A 47-year-old man who works as a carpenter reports a 12-month history of painful mechanical locking of his dominant elbow in the mid range of movement. He also has progressive pain at terminal extension that has not responded to medication, rest, and intra-articular cortisone injection. Active range of movement is from 35 degrees to 130 degrees, and he has full pronation and supination. The ulnar nerve is stable, and he has no subjective or objective neurologic dysfunction in the hand. Radiographs are shown in Figures 22a and 22b. What is the most appropriate treatment?

 

1. Oral corticosteroid medication and changes in job activities

2. Soft-tissue interposition arthroplasty

3. Arthroscopic capsular release, loose body removal, and osteophyte decompression

4. Radial head arthroplasty 5- Total elbow arthroplasty

 

DISCUSSION: The most appropriate treatment is arthroscopic capsular release, loose body removal, and osteophyte decompression. The patient has moderate osteoarthritis of the dominant elbow, with mechanical symptoms suggestive of loose osteochondral body formation. Because the patient has failed to respond to the typical nonsurgical therapeutic options, it is unlikely that further oral medication will be helpful, and job modification may not be practical at this stage. Soft-tissue arthroplasty may be reasonable to consider when less invasive methods, such as arthroscopy, fail.

Isolated radial head arthroplasty would not sufficiently address the symptoms. Total elbow arthroplasty is indicated in cases of more advanced disease in older patients with lower physical demands. The Preferred Response to Question # 22 is 3.

 

23.A healthy 33-year-old man falls from a ladder onto his outstretched arm. He sustains the injury shown in Figure 23. This is an isolated injury. What is the most appropriate treatment?

1. Fragment excision

2. Sling for 1 week, followed by early range of motion 3- Open reduction and internal fixation

4- Radial head arthroplasty 5- Capitellar replacement

 

DISCUSSION: The injury is a coronal plane fracture of the distal humerus. The radiograph shows the classic "double-bubble" sign. These fractures often include the capitellum; however, frequently, the fracture extends medially to involve a portion of the trochlea. Small articular fragments may be amenable to simple fragment excision; excision of large fragments can result in posttraumatic arthritis or instability if a medial collateral ligament injury is present. Fractures involving a significant portion of the articular surface should be treated with reduction and fixation to reestablish a congruent joint surface. Closed reduction and percutaneous pinning has shown variable success rates. Open reduction is the treatment of choice because it allows for precise restoration of the articular surface and more rigid fixation, more safely permitting early range of motion. Capitellar replacement is not recommended in a young active patient with a repairable fracture. Preferred Response # 23 is 3.

 

24..A 74-year-old woman with rheumatoid arthritis has pain in the shoulder that has failed to respond to nonsurgical management. AP and axillary radiographs are shown in Figures 24a and 24b. Active forward elevation is 120 degrees and external rotation is 30 degrees. At the time of surgery, a 1-cm rotator cuff tear is found, which is repairable. Which of the following treatment options will result in the most predictable pain relief and function?

1- Total shoulder arthroplasty and rotator cuff repair 2- Rotator cuff repair

3. Reverse total shoulder arthroplasty

4. Interpositional arthroplasty and rotator cuff repair 5- Hemiarthroplasty and rotator cuff repair

 

DISCUSSION: Most studies have shown that total shoulder arthroplasties yield better pain relief and improved forward elevation when compared with hemiarthroplasty in patients with rheumatoid arthritis. Patients with repairable rotator cuff tears should undergo repair at the time of surgery because good results have been shown. Reverse arthroplasties are not indicated with rotator cuff tears that are repairable, and interpositional arthroplasties are not indicated for elderly patients. Pr Res # 24 is 1.

 

25..A 66-year-old man who underwent shoulder arthroplasty 7 years ago reports progressively worsening shoulder pain for the past 4 weeks after hospital discharge for community-acquired pneumonia. He is afebrile and reports no chills or night sweats. Laboratory studies show a white blood cell count of 11,200/mm3 and an erythrocyte sedimentation rate of 25/h. Shoulder radiographs are negative for fracture, dislocation, or signs of implant loosening. What is the most appropriate management?

1. Follow-up in 2 weeks with a repeat white blood cell count and erythrocyte sedimentation rate

2. Shoulder aspiration with Gram stain and culture of fluid

3. Prescription strength nonsteroidal anti-inflammatory drugs 4- Physical therapy for shoulder stretching and modalities

5- Emergent surgical irrigation, debridement, and revision shoulder arthroplasty DISCUSSION: The patient may have hematologic spread of the pulmonary infection to the shoulder arthroplasty; however, further work-up is necessary at this point. The elevated laboratory studies may still be secondary to the pulmonary infection.

Aspiration of the shoulder joint with stat Gram stain and culture of the fluid is indicated. If the aspirate shows signs of infection and irrigation and debridement is indicated, complete revision of the well-seated implants may not be necessary.

Physical therapy and nonsteroidal anti-inflammatory drugs are not indicated until the possibility of a shoulder infection has been ruled out. A wait of 2 weeks to repeat the laboratory values, in the presence of new shoulder pain, is contraindicated. The Preferred Response to Question # 25 is 2.

 

26.A 25-year-old man has a swollen painful sternoclavicular joint. He denies using drugs or having any other medical conditions. Examination does not reveal any evidence of a dislocation. The joint is tender and slightly warm. The chest radiograph is normal. What is the next most appropriate step in management?

1- CT of the chest 2- Bone scan

3- Irrigation and debridement in the operating room 4- Lidocaine injection of the joint

5- Physical therapy

 

DISCUSSION: A common cause of a septic sternoclavicular (SC) joint is IV drug use. Recently, however, there have been case reports of septic SC joints in patients without a history of drug use; therefore, this history should not be used as a predictor of severity or extension beyond the SC joint capsule. Because of the risk of extension of the infection to the retrosternal area and pericardium, it is recommended that a CT scan be obtained before proceeding with any surgical management. A bone scan cannot accurately show abscess extension into the retrosternal area. Lidocaine injection and physical therapy should not be considered until infection is ruled out. The Preferred Response to Question # 26 is 1.

 

27. Elbow distraction interposition arthroplasty may be most appropriate treatment for which of the following patient profiles?

1- 25-year-old woman with destructive juvenile rheumatoid arthritis 2- 41-year-old male laborer with posttraumatic arthritis of the elbow 3- 44-year-old woman with distal humerus osteonecrosis and collapse 4- 65-year-old man with painful primary elbow osteoarthritis

5- 70-year-old sedentary woman with end-stage rheumatoid arthritis

 

DISCUSSION: Elbow interposition arthroplasty is reserved for younger, active patients who may otherwise be candidates for prosthetic replacement. Osteoarthritis, posttraumatic arthritis, and rheumatoid arthritis patients may all be candidates for interposition arthroplasty if bone stock is preserved and the elbow maintains inherent stability. Primary osteoarthritis may also be treated with ulnohumeral arthroplasty (ie,

 

Outerbridge) or arthroscopic debridement with release. Patients with destructive juvenile rheumatoid arthritis and distal humerus osteonecrosis would better benefit from prosthetic replacement because of bone loss issues. The Preferred Respo# 27 is 2.

 

28. An active 22-year-old man falls onto his outstretched arm, sustaining the fracture shown in Figures 28a and 28b. Examination is notable for tenderness over the radial aspect of the elbow, as well as tenderness at the wrist. Radiographs of the wrist show no fracture or dislocation. What is the most appropriate treatment?

1. Excision of the radial head

2. Silastic replacement of the radial head 3- Metallic replacement of the radial head

4. Open reduction and internal fixation of the radial head

5. Sling use and early motion

 

DISCUSSION: In a young patient, the treatment of choice is open reduction and internal fixation; in patients with a nonreconstructible radial head, metallic replacement can be performed. Fractures

of the radial head are classified by Mason into type I, II, and III. Type I fractures are nondisplaced, and can be treated with a sling and early motion. Type II fractures are fractures of a single piece with greater than 2 mm of displacement, and can be treated with a sling and motion if they are not associated with instability or mechanical blocks to motion. Type III fractures are comminuted, displaced fractures. The fracture shown in the figures is a type III fracture with less than three fragments. Fractures with greater than three fragments have been shown to have generally poor outcomes with open reduction and internal fixation; fractures with three or fewer fragments had better results with fewer complications. Silastic replacement has been associated with uniformly poor long-term results. Whereas radial head excision has excellent results in the treatment of radiocapitellar arthritis, it is contraindicated in this patient because he has wrist pain, suggesting an injury to the interosseous membrane (Essex-Lopresti lesion), and radial head excision has a high likelihood of leading to proximal radial migration and distal radioulnar joint instability. The Preferred Respon # 28 is 4.

 

29..Which of the following is considered a contraindication to the use of a reverse total shoulder arthroplasty?

1- Prior shoulder joint infection 2- Pseudoparalysis

3. Prior partial acromioplasty

4. Absent glenohumeral joint space narrowing 5- Axillary neuropathy

 

DISCUSSION: The reverse total shoulder arthroplasty depends on a functional deltoid muscle which is innervated by the axillary nerve to restore elevation for the patient. Pseudoparalysis is an indication for a reverse shoulder arthroplasty. Acromioplasty has not been correlated with poor results with a reverse shoulder arthroplasty. As long as the patient does not have an active infection, prior infections are not a contraindication. Patients can still have pain and pseudoparalysis from a chronic rotator cuff tear, despite having normal cartilage, and they will still benefit from a reverse total shoulder arthroplasty if other treatments have failed. Pr Res# 29 is 5.

 

30..Figure 30 shows the radiograph of an 82-year-old woman who reports a 1-month history of shoulder pain. She is able to actively elevate her arm to 150 degrees but is experiencing discomfort. Her sleep is disrupted because of the shoulder pain. What is the most appropriate management?

1- Total shoulder arthroplasty 2- Hemiarthroplasty

3. Reverse shoulder arthroplasty

4. Arthroscopic shoulder debridement

5. Trial of anti-inflammatory medication or cortisone injection and/or deltoid strengthening

DISCUSSION: The patient is experiencing rotator cuff tear arthropathy. Given that this is the first medical treatment she has sought, a nonsurgical treatment plan of anti- inflammatory medication or a corticosteroid injection is warranted. Proceeding to the operating room without a trial of nonsurgical management is not indicated in this patient population. Surgical procedures may be necessary in the future if nonsurgical measures fail. The Preferred Response to Question # 30 is 5.

 

31..A 53-year-old woman reports a 4-month history of gradual onset diffuse shoulder pain and limited function. She has had no prior treatment, and her medical history is unremarkable. Examination reveals globally painful active range of motion to 120 degrees forward elevation, 25 degrees external rotation with the arm at the side, and internal rotation to the sacrum. Passive range of motion is also limited in comparison with the contralateral shoulder. Radiographs are shown in Figures 31a through 31c. What is the most appropriate management?

 

1. Sling immobilization and rest

2. Physical therapy for aggressive stretching

3. Intra-articular corticosteroid injection and stretching program 4- Manipulation of the shoulder under anesthesia

5- Arthroscopic subacromial decompression and capsular release

 

DISCUSSION: The patient has stage II adhesive capsulitis. Patients most commonly affected are women between the ages of 40 and 60, and most cases are considered idiopathic. The preferred method of treatment is an intra-articular corticosteroid injection to decrease inflammation in the joint and allow for a gentle stretching therapy program. Sling immobilization is contraindicated because it likely will promote further joint contracture and prolonged recovery. Aggressive capsular stretching in the early stages of the disease is often counterproductive, unless pain can be adequately controlled with medication or injections. Manipulation under anesthesia and arthroscopic surgical treatment are used when symptoms remain refractory despite initial nonsurgical management. The Preferred Response to Question # 31 is 3.

 

32.A 65-year-old woman with rheumatoid arthritis is unable to actively extend her index, middle, ring, and little fingers secondary to tendon rupture. In performing a flexor digitorum sublimis (FDS) of the middle/ring finger to extensor digitorum communis (EDC) transfer to restore active metacarpophalangeal (MCP) joint extension, the FDS should be passed

1. ulnarly, around the ulna in a dorsal direction.

2. radially, around the radius in a dorsal direction. 3- through the interosseous membrane.

4. through the intermetacarpal spaces between the index, middle, ring, and little fingers.

5. through the lumbrical canals of the index, middle, ring, and little fingers.

 

DISCUSSION: Although the early use of FDS as a transfer to restore finger extension in patients with radial nerve palsy was performed by passing the tendon through the interosseous membrane, Nalebuff and Patel later modified this procedure for the rheumatoid arthritis patient by passing the FDS radially, around the radius in a dorsal direction. They felt that this provided a number of advantages, including: 1. technical ease, 2. avoidance of synovial disease on the dorsum of the wrist, and 3. correction of ulnar deviation of the fingers through the line of pull from the radial side of the forearm. The Preferred Response to Question # 32 is 2.

 

33. A patient sustains a traumatic injury to the right shoulder. An axial CT scan is shown in Figure 33. Management should include which of the following?

1. Sling and swathe

2. Excision of fragment 3- Closed reduction

4- Open reduction and internal fixation 5- Hemiarthroplasty

 

DISCUSSION: The 2-D axial CT scan shows a displaced glenoid fracture involving approximately one third of the articular surface. Anatomic restoration by an open reduction and internal fixation is necessary to avoid traumatic osteoarthrosis. Removal of the fragment would likely result in instability of the joint. Closed reduction of the

 

fragment is not possible in this injury, and there is no indication for a hemiarthroplasty because the humerus is not involved. The Preferred Response to Question # 33 is 4.

 

34. A 47-year-old man undergoes a posterior cervical procedure for a benign tumor. Postoperatively, severe dysfunction with decreased forward elevation and abduction develops and he has lateral winging of the scapula. What is the recommended treatment to best restore motion and function?

1- Rhomboids and levator transfer 2- Split pectoralis major transfer

3- Long head of triceps transfer 4- Scapulothoracic fusion

5- Infraspinatus transfer

 

DISCUSSION: The patient has sustained a permanent injury to the spinal accessory nerve and has resultant scapular winging (lateral winging) because of trapezius palsy with weakness in abduction and forward elevation. The modified Eden-Lange procedure (transfer of the rhomboid minor, major, and levator scapulae) has been shown to reliably restore range of motion and function. Split pectoralis major transfer is performed to restore serratus anterior function. The long head of the triceps and infraspinatus tendon transfers are rarely used for any shoulder muscle transfer. A scapulothoracic fusion can also be performed for this problem, but the results are not as effective as the Eden-Lange procedure. The Preferred Response # 34 is 1.

 

35. The standard Bankart lesion involves detachment of the labrum along with which of the following capsular ligaments?

1. Superior glenohumeral ligament and coracohumeral ligament

2. Superior glenohumeral ligament and middle glenohumeral ligament 3- Middle glenohumeral ligament and inferior glenohumeral ligament 4- Inferior glenohumeral ligament

5- Superior glenohumeral ligament, middle glenohumeral ligament, and inferior glenohumeral ligame

 

DISCUSSION: The Bankart lesion involves detachment of the labrum corresponding to the attachment of the middle and inferior glenohumeral ligaments. The superior glenohumeral ligament and the coracohumeral ligament are too superior, inserting near the biceps tendon, and play no role in the Bankart lesion. The Pre Res# 35 is 3.

 

36,Complications following a reverse shoulder prosthesis occur most frequently when performed for what diagnosis?

1- Rotator cuff tear arthropathy with superior escape 2- Massive rotator cuff tear with osteoarthritis

3- Fracture-dislocation of the glenohumeral joint 4- Four-part proximal humeral fractures

5- Failed shoulder arthroplasty

 

DISCUSSION: Revision following failed shoulder arthroplasty is associated with the highest complication rates, including dislocation, loosening, and decreased function. However, when performed for rotator cuff tear arthropathy or failed rotator cuff repairs, the complication rate is reasonably low. The complication rate is unknown when the reverse total shoulder is used for fracture-dislocation or acute four-part fractures of the proximal humerus. The Preferred Response to Question # 36 is 5.

 

37.A patient has severe cubital tunnel syndrome and marked wasting of the intrinsic muscles of the hand. Why is the little finger held in an abducted position?

1. Accessory slip of the extensor digiti minimi attaching to the abductor digiti minimi tendon

2. Tetanic contraction of the abductor digiti minimi

3. Radial collateral ligament insufficiency of the fifth metacarpophalangeal (MCP) joint

4. Unopposed pull of the flexor digitorum profundus

5. Muscle innervation from a Martin-Gruber anastomosis

 

DISCUSSION: A Wartenberg's sign, where the little finger is held in an abducted position, is associated with an ulnar nerve palsy. This happens when there is an accessory slip of the extensor digiti minimi, which is innervated by the radial nerve,

 

crossing ulnar to the center of the MCP joint to attach to the tendon of the abductor digiti minimi and the proximal phalanx. The abductor digiti minimi and the volar interosseous muscles are both innervated by the ulnar nerve; therefore, there is no tetanic contraction of the abductor digiti minimi.

Unopposed pull of the flexor digitorum profundus results in excess flexion of the proximal interphalangeal and distal interphalangeal joints of the hand as seen with a clawing-type deformity. A Martin-Gruber anastomosis, which is a neural connection between the ulnar and median nerves in the forearm, cannot explain this finger position. The Preferred Response to Question # 37 is 1.

 

38Figure 38 shows the radiograph of a 41-year-old man who reports ulnar palmar pain, decreased sensibility and tingling in the ring and little fingers, and a grating sensation in the ulnar fingers with motion. He reports that he sustained a fall on an outstretched hand 6 months ago. What is the most appropriate treatment option?

 

1- Ulnar gutter cast 2- Short arm cast

3. Carpal tunnel release

4. Decompression of Guyon's canal

5. Excision of a fractured hook of hamate

 

DISCUSSION: Excision of a fractured hook of hamate is the most appropriate management. The patient has a hook of hamate fracture with ulnar nerve compression and irritation of the flexor tendons by the fracture surfaces; this puts the tendons at risk for rupture. Cast treatment will most likely not gain union of the fracture and will not address the nerve or tendon problems. Decompression of Guyon's canal alone will not address the tendon issue.

The Preferred Response to Question # 38 is 5.

 

39. A 22-year-old javelin thrower reports that he has had increasing discomfort in his right elbow and loss of distance from his throws for the past 3 months. Examination reveals tenderness over the medial elbow. Application of valgus torque to the elbow through a passive range of motion elicits pain from 70 degrees to 120 degrees of flexion, with no pain at the limits of extension. What structure is primarily responsible for the patient's symptoms?

 

1- Anterior bundle of the medial collateral ligament (MCL) 2- Posterior bundle of the MCL

3. Annular ligament

4. Triceps insertion

5. Olecranon osteophytes

 

DISCUSSION: The MCL is divided into anterior and posterior bundles; the anterior bundle is subdivided into anterior and posterior bands. Sectioning studies showed that the anterior band of the anterior bundle is the primary restraint to valgus stress at 30 degrees, 60 degrees, and 90 degrees; the posterior band of the anterior bundle is the primary restraint at 120 degrees. Medial elbow pathology in a throwing athlete can present with pain, instability, loss of velocity or control, or with ulnar nerve symptoms. Differentiating between different causes of disability can be largely accomplished through physical examination. The moving valgus stress test is performed by applying a valgus stress to a maximally flexed elbow, then passively extending the elbow.

Reproduction of the patient's symptoms in the mid arc of flexion suggests MCL insufficiency. Pain at the end point of extension suggests posterior compartment symptoms, which were not present in this patient. The posterior bundle is a secondary stabilizer at 30 degrees of flexion, and not susceptible to valgus load when the anterior bundle is intact. The annular ligament and triceps insertion are not involved with medial instability of the elbow. Olecranon osteophytes likely cause pain in terminal extension of the elbow.

The Preferred Response to Question # 39 is 1.

 

40. Which of the following statements best describes the typical early presentation of osteochondritis dissecans of the elbow?

1- Often associated with loss of elbow extension 2- Often associated with catching or locking

3- Involves the capitellum or lateral trochlea 4- Presents in boys younger than age 10 years

5- Outlining of the margins of the lesion on MR arthrogram is a good prognostic sign

 

DISCUSSION: This condition is the result of repetitive valgus overload of the radiocapitellar joint in the immature elbow. The clinical presentation is of lateral elbow pain and loss of extension in a juvenile older than age 10 years. Panner's disease typically affects the capitellum in boys younger than age 10 years. Osteochondritis dissecans (OCD) of the elbow affects the capitellum and occasionally the radial head.

Fracturing of the OCD region can lead to an unstable fragment with margins outlined on an MR arthrogram and can progress to loose bodies that cause clinical catching or locking. These are typically late signs with a poorer prognosis. The Pre Re# 40 is 1.

 

41. Two years after undergoing a total shoulder arthroplasty, a patient reports increasing pain, stiffness, and swelling, and has an increased white blood cell count. Radiographs show lucencies around the glenoid and humeral components. You suspect infection. Which of the following is the most likely responsible organism?

1. Staphylococcus aureus

2. Staphylococcus epidermidis

3. Propionibacterium acnes

4. Escherichia coli

5. Pseudomonas aeruginosa

 

DISCUSSION: The most likely organism to cause late infection in shoulder arthroplasty is Propionibacterium acnes. This is a slow growing organism that is present in over 50% of chronic infections. Staphylococcus epidermidis is the second most likely organism in this setting, present in 15% of cases. The other three organisms are unlikely to present with this clinical picture. The Preferred Response to Question # 41 is 3.

 

42. The MRI scan of a patient with symptomatic shoulder pain reveals subacromial bursitis. What markers have been shown to be significant contributors to this pain? 1- Metalloproteases

2. Alpha fetoprotein

3. Prostate-specific antigen (PSA) 4- Carcinoembryonic antigen (CEA) 5- CA-125

 

DISCUSSION: Several inflammatory markers have been shown to be elevated in subacromial bursitis. These include metalloproteases, tumor necrosis factors, and cyclooxygenase 1 and 2. The other answers provided are all tumor markers and not typically present in routine subacromial bursitis ("impingement syndrome"). The Preferred Response to Question # 42 is 1.

 

44. An 11-year-old boy sustained a fall onto his outstretched right hand while playing soccer. Examination reveals tenderness in the anatomic snuff box. Wrist radiographs reveal a scaphoid fracture. This injury most commonly presents with which of the following?

1- Within the distal one third of the scaphoid 2- Within the middle one third of the scaphoid

3. Within the proximal one third of the scaphoid

4. In association with injury to the scapholunate ligament 5- As a unicortical injury

 

DISCUSSION: The distal pole of the scaphoid ossifies before the proximal pole, resulting in an increased incidence of distal one third fractures and avulsions of the distal radial aspect of the scaphoid (59% to 94%) as compared with adults. Scaphoid fractures in the pediatric population can be seen in association with distal radius fractures, but are not commonly associated with ligamentous injury. While 23% of pediatric scaphoid fractures are unicortical, bicortical injuries still predominate. Most pediatric scaphoid fractures are nondisplaced and heal with 4 to 6 weeks of immobilization. As in adults, displaced fractures are treated with open reduction and internal fixation. The Preferred Response to Question # 44 is 1.

45. A 25-year-old man was involved in an altercation. Examination reveals loss of active extension of the middle finger metacarpophalangeal (MCP) joint. A diagnosis of sagittal band rupture is made. Which of the following is considered the key diagnostic finding?

1. Extensor lag of 30 degrees

2. Extensor lag of 60 degrees

3. Positive Bunnell intrinsic tightness test

4. Ability to maintain active extension of the interphalangeal joints 5- Ability to maintain MCP extension after passive extension

 

DISCUSSION: In sagittal band rupture, the extensor tendon may subluxate into the valley between the metacarpal heads. The patient will not be able to actively extend the MCP joint from a flexed position with the subluxated tendon, but will be able to maintain MCP extension after it has been passively extended. Extensor lags can have other etiologies other than extensor digitorum communis subluxation such as tendon laceration or rupture, posterior interosseous nerve palsy, but in these conditions, patients cannot maintain MCP extension. Active interphalangeal extension can be achieved with the intrinsic muscles that are not affected by sagittal band rupture.

The Preferred Response to Question # 45 is 5.

 

46. A 45-year-old man has been treated nonsurgically with a fracture brace for a closed midshaft humeral fracture. At 16 weeks after his injury he has continued pain and gross motion at the fracture site. A radiograph is shown in Figure 46. What is the most appropriate and reliable management at this point?

1. Sling immobilization and electrical stimulation

2. Continued functional bracing and repeat radiographs in 6 weeks 3- Closed reduction and intramedullary nailing

4- Open reduction and compression plating with autograft 5- Open reduction with fully locked plating and allograft

 

DISCUSSION: The radiograph reveals a delayed union of a midshaft humerus fracture that has been treated appropriately with closed fracture bracing. The gold standard remains compression plate

 

fixation with autograft, most commonly iliac crest bone graft. Intramedullary nailing is associated with a higher incidence of nonunion and iatrogenic rotator cuff damage.

Fully locked plating is unnecessary along with allograft in this setting. Immobilization with electrical stimulation offers little success in this atrophic delayed union.

The Preferred Response to Question # 46 is 4.

 

47. A 45-year-old man reports a history of a popping sensation and pain in the right shoulder while lifting boxes 6 months ago. The pain has persisted with loss of motion of the shoulder. Radiographs and MRI scans are shown in Figures 47a through 47d.

Which of the following studies is likely to produce a significant positive result?

 

1. Rheumatoid factor

2. HLA-B27

3. Synovial fluid analysis

4. MRI of the upper cervical spine

5. Urine screen for tetrahydrocannabinol (THC)

 

DISCUSSION: The patient has a neuropathic joint secondary to syringomyelia that can be seen on a cervical MRI scan. The patient sustained minimal trauma that lead to a chronic anterior glenohumeral dislocation. He did not seek treatment for several months and has a massive rotator cuff tear and hygroma on MRI in addition to the chronic dislocation. Rheumatoid arthritis does not present with a neuropathic picture, except theoretically as the result of numerous intra-articular cortisone injections. This Charcot picture is inconsistent with ankylosing spondylitis or gout. Cannabis use is not typically associated with seizures that could produce anterior as well as posterior shoulder dislocations.

The Preferred Response to Question # 47 is 4.

 

48. A 55-year-old patient with rheumatoid arthritis reports increasing elbow pain and swelling for the past 2 months. She underwent a cemented, semiconstrained elbow arthroplasty 8 years ago. Laboratory studies show a normal peripheral white blood cell count; however, the erythrocyte sedimentation rate and C-reactive protein level are elevated. Radiographs are shown in Figures 48a and 48b. Which of the following organisms is most difficult to eradicate?

 

1. Streptococcus viridans

2. Staphylococcus epidermidis

3. Escherichia coli

4. Vibrio parahaemolyticus

5. Clostridium difficile

 

DISCUSSION: The patient's history and radiographs are suspicious for a relatively aggressive infection. Staphylococcus epidermidis is difficult to eradicate because of its encapsulation. The lytic area surrounding both the ulnar and humeral components suggests that the prosthesis is also loose. This revision will require component removal, antibiotic spacer placement, and parenteral antibiotics. The Pre Res# 48 is 2.

 

49What is the most common complication associated with the exposure method shown in Figure 49?

1. Ulnar nerve injury

2. Symptomatic hardware

3. Lateral instability

4. Medial instability

5. Nonunion

 

DISCUSSION: Olecranon osteotomy provides excellent exposure of the articular surface of the distal humerus, and allows for direct visualization of the entirety of the distal humerus. Complications associated with this exposure include infection, nonunion, hardware failure, symptomatic hardware, and improperly placed hardware, limiting forearm rotation. Recent studies have shown a nonunion rate of 0% to 2%; the lack of

 

overlying soft tissue makes symptomatic hardware common, with rates from 8% to 33%. Additionally, olecranon fixation is often removed at the time of other subsequent procedures performed on the elbow. Olecranon osteotomy does not destabilize the collateral ligaments of the elbow. The Preferred Response to Question # 49 is 2.

 

50. What is the effect of shortening of metacarpal fractures?

1- Causes the greatest degree of extensor lag in the index finger 2- Causes the greatest degree of extensor lag in the little finger

3- Results in an average extensor lag of 7 degrees for every 2 mm of shortening 4- Results in an average extensor lag of 14 degrees for every 2 mm of shortening 5- Has no effect on grip strength

DISCUSSION: Cadaveric models have demonstrated a 7-degree extensor lag for every 2 mm of metacarpal shortening, with the amount of lag increasing in a linear fashion.

There was no statistical difference in the amount of lag in regard to the digit involved. Based on muscle length-tension relationships, cadaveric models have also been used to demonstrate an 8% loss of power secondary to decreased interosseous force generation with 2 mm of shortening. Because the intrinsic muscles of the hand contribute anywhere from 40% to 90% of grip strength, decreased interosseous force generation secondary to metacarpal shortening will invariably cause a decrease in grip strength. The Preferred Response to Question # 50 is 3.

 

51. Figures 51a and 51b show the AP and lateral radiographs of the elbow of a 26- year-old man who fell. Closed reduction was performed in the emergency department, and management consisted of immobilization for 3 weeks prior to the initiation of motion. At 12 weeks after injury, he reports continued feelings of instability and catching in his elbow when using his arms to rise from a chair. Which of the following procedures needs to be performed, at a minimum, to reestablish stability of the elbow?

1. Medial collateral ligament repair

2. Medial collateral ligament reconstruction 3- Hinged external fixation

4. Lateral collateral ligament repair

5. Lateral collateral ligament reconstruction

 

DISCUSSION: The patient has chronic posterolateral instability of the elbow following dislocation. The lateral collateral ligament complex is responsible for maintaining stability of the elbow. Because of the chronicity of the injury, the ligamentous tissues are frequently attenuated and not amenable to simple repair; while the native ligament can be imbricated, reconstruction with allograft or autograft is recommended. Medial collateral ligament reconstruction or hinged external fixation is needed only if restoration of the lateral ligamentous complex does not restore elbow stability; however, these procedures are rarely required. Lateral elbow pain when rising from a chair is equivalent to a positive pivot shift test. Preferred Resp # 51 is 5. 52 What is the most common mode of failure following unconstrained total elbow arthroplasty?

1. Polyethylene wear

2. Bushing wear

3. Instability

4. Component fracture

5. Loosening of the humeral component

DISCUSSION: Elbow instability after placement of an unconstrained implant is most often the result of ligamentous insufficiency that can occur late after the index procedure. Instability can also occur from component malpositioning that creates undue stress to the collateral ligaments during the life of the prosthesis. Instability leads to revision surgery in many patients. Polyethylene wear and bushing wear are more common in linked and semiconstrained elbow arthroplasties. Loosening of humeral components may occur with aseptic or septic disease. Component fracture is uncommon. The Preferred Response to Question # 52 is 3.

53. A 41-year-old woman with diabetes mellitus fell onto her outstretched arm and sustained an injury to the right elbow. Radiographs are shown in Figures 53a and 53b. What is the most appropriate management?

1. Open reduction and internal fixation

2. MRI of the elbow to assess the integrity of the collateral ligaments

3. Immobilization in a long arm cast for 3 weeks

4. Short-term immobilization in a splint, followed by early motion exercises 5- Radial head replacement

 

DISCUSSION: The radiographs reveal a capitellum fracture with anterior displacement. To regain concentric and stable joint motion, this fragment requires reduction and stabilization. Without a joint dislocation, the ligaments are unlikely to be damaged and do not require further assessment with MRI. Closed reduction may be considered, but is unlikely to be successful. Without anatomic reduction of the fracture fragment, immobilization in either a long arm cast or a splint will not provide optimal outcomes. Based on the radiographs, the radial head is intact and does not require replacement. The Preferred Response to Question # 53 is 1.

 

54. A 38-year-old man reports a 6-week history of shoulder pain and stiffness after falling on the stairs and landing onto the affected side. Radiographs are shown in Figures 54a and 54b. What is the most appropriate treatment?

1- Physical therapy including ultrasound and gentle stretches 2- Closed manipulation of the shoulder

3. MRI and possible rotator cuff repair

4. Open glenohumeral reduction, with possible lesser tuberosity transfer 5- Shoulder hemiarthroplasty

 

DISCUSSION: The patient has a chronic posterior shoulder dislocation of 6-weeks duration. A CT scan will provide preoperative information regarding the size of the McLaughlin or reverse Hill-Sachs lesion. Open glenohumeral reduction with transfer of the lesser tuberosity and attached subscapularis has been shown to be successful in stabilizing a posterior dislocation. Closed reduction is highly unlikely to achieve a reduction and may cause displacement of an unrecognized humeral surgical neck

 

fracture. Hemiarthroplasty would be considered for lesions involving more than 50% of the humeral head or when the joint has been dislocated for several months and late collapse of the head postreduction is likely. Rotator cuff tears are not commonly associated with posterior shoulder dislocation. The Preferred Response # 54 is 4.

 

55. A 22-year-old motorcyclist sustains open fractures to the left radial shaft and second and third metacarpals with exposed extensor tendon and bone. The fractures are approached via the dorsal open wounds of the forearm and hand with no additional incisions made. The radiograph and clinical photograph of the remaining defect in the hand are shown in Figures 55a and 55b. The remaining wound can be most appropriately covered with which of the following?

1. Split-thickness skin grafting

2. Posterior interosseous rotational flap 3- Radial forearm rotational flap

4. Groin flap

5. Free lateral arm flap

 

DISCUSSION: After adequate debridement, there is exposed bone, tendon, and hardware. Split-thickness skin grafting over exposed tendon will not have a viable bed to support the graft. The tendons would not have healthy surrounding tissue, resulting in poor tendon gliding. The dorsal wound has disrupted the posterior interosseous artery that runs in the septum between the extensor digiti minimi and the extensor carpi ulnaris. Following the reconstructive ladder, the radial forearm rotational flap accomplishes wound coverage with a local flap rather than a groin flap (a distant flap) or a lateral arm flap (microvascular free tissue transfer). The Preferred Resp # 55 is 3.

 

56. What preoperative patient factor has been shown to most closely correlate with poor results after a latissiumus dorsi transfer for an irreparable rotator cuff tear?

1- Age of younger than 70 years 2- Positive lift-off test

3. Previous shoulder surgery

4. Loss of passive external rotation 5- Male gender

 

DISCUSSION: Patients with a positive lift-off test have a tear of the subscapularis tendon. Patients with a subscapularis tendon tear did much worse than other patients in the studies by Gerber and associates and Irlenbusch and associates. Latissimus dorsi muscle transfer during the primary surgery when a complete rotator cuff repair could not be performed results in a better outcome than a muscle transfer done as a second surgery, but other prior surgery was not shown to affect transfer results. Iannotti and associates found poor results in patients who were female or had external rotation and forward flexion weakness. The Preferred Response to Question # 56 is 2.

 

57. A 22-year-old man reports that he initially dislocated his shoulder while playing basketball 2 years ago and was subsequently treated with an arthroscopic Bankart repair. Despite appropriate rehabilitation, the patient continues to report recurrent instability. An axillary view radiograph and CT scan are shown in Figures 57a and 57b. What is the most appropriate management at this time?

 

1. Supervised physical therapy

2. Arthroscopic capsulorrhaphy and labral repair

3. Open shoulder capsulorrhaphy and labral repair 4- Open shoulder capsulorrhaphy and bone block 5- Shoulder arthrodesis

 

DISCUSSION: Although the changes are subtle on the radiograph, an anterior inferior glenoid bone defect is clearly evident on the CT scan. With loss of greater than 20% to 25% of the glenoid width, patients may experience persistent instability despite appropriate labral repair and capsulorrhaphy. Therefore, nonsurgical management with supervised therapy or surgical treatments that do not address the bony defect, such as arthroscopic or open labral repair and capsulorrhaphy, are not likely to stabilize the joint. An open shoulder stabilization procedure with a bone block should address the defect and stabilize the joint. Shoulder arthrodesis is not warranted in this patient at this time because the shoulder is likely salvageable.

Preferred Resp # 57 is 4.

 

58. Scapular notching following reverse shoulder arthroplasty may be minimized by what technical modification?

1. Horizontal humeral cut

2. Superior inclination of the baseplate 3- Inferior inclination of the baseplate 4- Use of a 36-mm glenosphere

5- Use of a retentive polyethylene liner

DISCUSSION: Biomechanical studies have shown that a 10-degree inferior inclination may decrease scapular notching; whereas superior inclination may worsen notching. Scapular notching has been recognized as a complication following reverse shoulder arthroplasty. Mechanical abutment of the humeral component possibly leads to erosion of the anteroinferior scapular neck, with progressive vulnerability of the inferior baseplate screws. A horizontal humeral cut does not affect notching because the humeral component causes the notching, not the bone on the humerus.

Glenosphere size has not been shown to correlate with scapular notching. The Preferred Response to Question # 58 is 3.

 

59. A 42-year-old man sustained a displaced humeral surgical neck fracture that was well-fixed with proximal humeral plating. Postoperative management consisted of a sling for 6 weeks, followed by physical therapy. Examination at 4 months after surgery revealed passive 90 degrees forward elevation, 10 degrees external rotation, and internal rotation to the greater trochanter. Radiographs show an anatomically healed fracture and no evidence of loose hardware; the plate is appropriately positioned. What is the most likely reason for the decreased range of motion?

1- Hardware impingement under the acromion 2- Rotator cuff tear

3- Postoperative scar tissue 4- Fracture malunion

5- Development of posttraumatic glenohumeral arthritis

 

DISCUSSION: The patient has reduced motion secondary to postoperative scarring. If excellent stability is obtained in the operating room, immediate passive motion can begin. Hardware impingement under the acromion will not account for limited external

 

rotation to the side. There is no evidence for a rotator cuff tear. A rotational malunion does not reduce motion in all planes. Four months after surgery it is unlikely that arthritic changes developed that are affecting his range of motion. The Preferred Response to Question # 59 is 3.

 

60. A 74-year-old man underwent a hemiarthroplasty with acromioplasty for rotator cuff tear arthropathy 2 years ago. Despite continued therapy, he is still unable to elevate his arm beyond 40 degrees. Attempted elevation is painful and demonstrates bulging in the anterosuperior aspect of his shoulder. Radiographs show a well- positioned hemiarthroplasty without signs of loosening. What is the most appropriate treatment for this patient?

1. Conversion to a total shoulder arthroplasty

2. Conversion to a reverse shoulder arthroplasty 3- Continued physical therapy

4. Cortisone injection

5. Anti-inflammatory medication

 

DISCUSSION: The patient is experiencing anterosuperior escape with attempted shoulder elevation. A conversion to a reverse shoulder arthroplasty will provide the stability to allow active elevation without subluxation. Further physical therapy, cortisone injection, or anti-inflammatory medication will not resolve this instability. A total shoulder arthroplasty is contraindicated because of the anterosuperior escape. The Preferred Response to Question # 60 is 2.

 

62 What is the name of the structure that is identified by the arrow on the sagittal T1-weighted MRI scan shown in Figure 62?

 

1. Infraspinatus

2. Teres minor

3. Subscapularis

4. Long head of the triceps 5- Latissimus dorsi

 

DISCUSSION: The sagittal T1-weighted MRI scan is useful for interpreting the quality of a muscle; the arrow is identifying the teres minor. The Preferred Response# 62 is 2.

 

64. What is the effect of performing a flexor tenosynovectomy with an open carpal tunnel release for idiopathic carpal tunnel syndrome?

1. Increased risk of nerve injury

2. Improved postoperative finger flexion

3. No added long-term clinical benefit versus open carpal tunnel release alone 4- Increased postoperative pain

5- Decreased recurrence of carpal tunnel syndrome

 

DISCUSSION: In patients with idiopathic carpal tunnel syndrome, flexor tenosynovectomy has not been shown to change the clinical outcome compared with open carpal tunnel release alone. This has been demonstrated in a randomized clinical trial of open carpal tunnel release with or without flexor tenosynovectomy. There has also been no evidence to suggest there is an added risk to performing the flexor tenosynovectomy. At time of surgery, the gross or histologic appearance of the flexor tenosynovium does not correlate with preoperative symptoms nor with clinical outcomes. The histology of the tenosynovium has been shown to be that of fibrosis in a setting of chronic inflammatory changes and no evidence of an acute inflammatory process exists. There may be an added role for flexor tenosynovectomy in non- idiopathic carpal tunnel syndrome such as in patients with renal disease or diabetes.

The Preferred Response to Question # 64 is 3.

 

65. A 22-year-old professional X-games motocross bike rider is thrown from his ride during a jump. He lands directly onto the point of his left shoulder and feels sharp pain. Examination reveals mild deformity over the lateral clavicle and bruising. A radiograph is shown in Figure 65. What is the most appropriate treatment?

1. Sling and swathe

2. Kenny-Howard brace

3. Percutaneous repair with smooth Kirschner wires

4. Open distal clavicle resection and transfer of the coracoacromial ligament 5- Open reduction and internal fixation

 

DISCUSSION: The history and radiograph indicate a traumatic displaced distal clavicle fracture in a professional athlete. Open reduction and internal fixation provides the best chance to heal and retain shoulder function. Smooth Kirschner wires are at risk for migration, and acute acromioclavicular joint reconstruction with coracoacromial ligament transfer is unnecessary when there is good quality bone stock. Nonsurgical management may lead to a high chance of nonunion. Kenny-Howard braces may cause skin irritation and breakdown. The Preferred Response to Question # 65 is 5.

 

66. What structure is at risk during arthroscopic resection of the capsule just anterior to the radial head and neck?

 

1. Radial nerve

2. Median nerve

3. Brachial artery

4. Lateral collateral ligament

5. Extensor carpi radialis brevis (ECRB) tendinous origin

 

DISCUSSION: Neurovascular injuries during anterior capsular release have been reported throughout the literature. During arthroscopic release/resection of the capsule located directly anterior to the radial head, the structure at greatest risk is the radial nerve, located along the anterolateral capsule just distal to the radiocapitellar joint. The radial nerve is consistently the neurovascular structure located closest to the capsule; it lies closer to the capsule distally than proximally. One cadaveric study noted the radial nerve to lie 9 mm from the capsule proximally, but only 3.5 mm from the capsule distally. The median nerve and brachial artery are also at risk, but are located more medially, and are protected by the brachialis. Similarly, the median nerve is located closer to the capsule distally than proximally; thus, the current recommendations are to release the anterior capsule from its humeral insertion rather than its distal insertion. The lateral collateral ligament is located posterior and lateral to the radial head, as is the ECRB origin, and should not be at risk during resection of the anterior capsule.

The Preferred Response to Question # 66 is 1.

 

67. Which of the follow scenarios is most likely to be amenable to a complete repair of a massive rotator cuff tear?

1. 42-year-old woman with rheumatoid arthritis

2. 45-year-old man with a tear associated with an anterior shoulder dislocation

3. 49-year-old man who underwent repair of an ipsilateral rotator cuff 3 years ago 4- 56-year-old male laborer with superior humeral migration on radiographs

5- 59-year-old woman with muscular atrophy noted in the supraspinatus fossa

 

DISCUSSION: Whereas a rotator cuff tear associated with an acute anterior dislocation in 45-year old patient may be massive, its acute nature typically means that significant retraction and atrophy of the musculature has not occurred. Therefore, repair is often complete and tension-free. A massive tear associated with rheumatoid arthritis is likely one of chronic attrition with poor tendon tissue because of the underlying disease and chronic corticosteroid use. Repairs of massive chronic rotator cuff tears have been reported to have a 50% rate of retear and this rate would be expected to be higher in the revision setting and with evident supraspinatus atrophy on physical examination.

Superior humeral migration on static upright radiographs indicates loss of the superior glenoid rim, leading to rotator cuff tear arthropathy. The Preferred Respon# 67 is 2.

 

68. Based on the clinical photograph, radiographs, and biopsy specimen shown in Figures 68a through 68d, what is the most likely diagnosis?

1- Calcium pyrophosphate deposition disease 2- Bacterial infection

3. Fungal infection

4. Gout

5. Giant cell tumor

 

DISCUSSION: The patient has gout. Unfortunately, gout may mimic several conditions affecting the small joints of the hand, including infection. The histologic specimen shows negatively birefringent intracellular rods consistent with gout. The histology rules out giant cell tumor and calcium pyrophosphate deposition disease. The Preferred Response to Question # 68 is 4.

 

69. Figures 69a and 69b show the radiographs of a 62-year-old man with severe radially sided wrist pain. Management has consisted of wrist splinting, nonsteroidal anti-inflammatory drugs, and activity modification, but he continues to have pain and reports difficulty sleeping. What is the most appropriate treatment for this patient?

1. Arthroscopic debridement

2. Open reduction and internal fixation

3. Scaphoid nonvascularized bone graft and screw fixation

4. Scaphoid vascularized bone graft and screw fixation

5. Scaphoid excision and 4-corner fusion

 

DISCUSSION: Scaphoidectomy and 4-bone fusion is the most appropriate management based on the

choices available. The patient has arthritic changes of SNAC (scaphoid nonunion advanced collapse) wrist, stage III. Stage I is at the radial styloid, stage II is at the radioscaphoid joint, and stage III is at the midcarpal joint. Arthroscopic debridement is not appropriate in patients with arthrosis. Attempting to achieve scaphoid union is only appropriate if there is no arthrosis or the changes are classified as stage I where radial styloidectomy can be performed. The Preferred Respo # 69 is 5.

 

70. A 30-year-old right-hand dominant man has pain in the right side of his upper torso and right extremity after being involved in a car accident. Examination reveals local tenderness, intact skin, and no dysphagia. Figure 70 shows an axial 2-D CT scan. Treatment should include which of the following?

 

1. Observation

2. Closed reduction

3. Closed reduction and percutaneous pinning 4- Closed reduction and a figure-of-8 splint

5- Open reduction and internal fixation

 

DISCUSSION: The CT scan shows a right anterior sternoclavicular joint dislocation. These injuries are best managed with simple observation. Anterior dislocations rarely have any long-term negative sequelae and are well tolerated, rarely leading to any clinically relevant symptoms. Therefore, attempts to reduce the joint are not necessary. The Preferred Response to Question # 70 is 1.

 

71. A 50-year-old man fell from a ladder onto his left shoulder and sustained the injury shown in the radiographs in Figures 71a and 71b. He underwent surgery with repair of the coracoclavicular ligaments and deltotrapezial fascia with coracoclavicular screw placement. Which of the following statements regarding postoperative complications is most accurate?

1- Hardware migration is more likely than with acromioclavicular pinning. 2- Failure of fixation is usually at the level of the clavicle.

3- Hardware removal is avoided to prevent late displacement. 4- Neurologic injury most likely involves the axilllary nerve.

5- Acromioclavicular arthritis is more likely than with nonsurgical management.

 

DISCUSSION: Whereas pain and functional disturbance may persist with nonsurgical management, the lack of articular surface contact prevents arthritic symptoms from developing. Cartilage injury caused by trauma and any persistent joint incongruity following repair would contribute to posttraumatic arthritis. Pinning across the

 

acromioclavicular joint has a high incidence of hardware migration and potential catastrophic consequences. Most cases of lost fixation of coracoclavicular screws are at the level of the thread purchase in the coracoid. Routine hardware removal at 8 to 12 weeks is recommended to avoid screw breakage because of natural movement between the clavicle and scapula. The axillary nerve passes around the inferior edge of the subscapularis and is anatomically distant to the the coracoid. The musculocutaneous nerve would have the closest anatomic position to the coracoid.

The Preferred Response to Question # 71 is 5.

 

72. Following total elbow arthroplasty, patients should be instructed to 1- return to impact activities such as golf or tennis.

2- permanently limit the load bearing of that arm to 5 pounds or less. 3- aggressively strengthen the triceps immediately following surgery.

4. immobilize the wrist and hand for 4 weeks postoperatively to minimize stress on the surgical site.

5. avoid pronation and supination to reduce torsional stress on the implant.

 

DISCUSSION: Current recommendations are for a lifetime restriction of load bearing and avoidance of impact activities following total elbow arthroplasty (TEA). TEA is a very effective procedure in reducing pain or reconstructing previously unreconstructable fractures. However, its usage must be tempered with the limitations of currently available prostheses. Aggressive triceps strengthening must be delayed following TEA to allow healing of the triceps attachment, regardless of the surgical approach. Wrist and hand mobilization should begin immediately postoperatively to prevent stiffness. Pronation and supination should not stress a humeral ulnar arthroplasty. The Preferred Response to Question # 72 is 2.

 

73. Which of the following is considered a contraindication to elbow arthroscopy? 1- Osteonecrosis of the elbow (Panner disease)

2. Loose body in the ulnohumeral joint

3. Status post open reduction and internal fixation of a radial head fracture 4- Ulnar neuropathy with prior submuscular ulnar nerve transposition

5- Elbow stiffness

DISCUSSION: Neurovascular complications are the most common complications reported with elbow arthroscopy. Any distortion in the anatomy of the elbow, especially when it involves neurovascular structures, such as a prior ulnar nerve transposition, increases the risk of neurovascular injury and is generally considered a contraindication to elbow arthroscopy. The other answers listed are either indications for arthroscopy or are not contraindications for the procedure.Prefer Respo# 73 is 4.

 

74. Which of the following pathologic entities is most often encountered in association with the clinical diagnosis of internal impingement of the shoulder? 1- Bankart lesion

2. SLAP tear

3. Anterior capsular contracture 4- Full-thickness rotator cuff tear

5- Humeral avulsion of glenohumeral ligaments (HAGL) lesion

 

DISCUSSION: A SLAP tear with posterior extension of the labral detachment is felt to be an important aspect of pathology in internal impingement. Whether this is the cause of condition or a result of the altered glenohumeral mechanics is still debated. While described as instability after repetitive microtrauma, it is not associated with Bankart or HAGL lesions as with gross dislocations. The current theories do not associate it with anterior capsular contracture. An articular-sided partial-thickness tear of the posterior supraspinatus can be seen but full-thickness tears have not been described. The Preferred Response to Question # 74 is 2.

 

75. A 17-year-old quarterback reports shoulder pain localized over the anterior aspect of the shoulder that occurs during the follow through phase of throwing. The pain worsens toward the end of the game, but becomes asymptomatic the next day. He denies any pain during the cocking phase of throwing or during normal daily activities. Examination reveals a negative relocation test and a negative posterior load and shift test. Motion of the shoulder is normal. An MRI arthrogram is shown in Figure 75. Based on the history, examination, and MRI findings, what initial treatment should be recommended?

 

1. Labrum repair

2. Capsular release

3. Labrum debridement

4. Physical therapy emphasizing a throwing program

5. Physical therapy emphasizing an internal rotation stretching program

 

DISCUSSION: The MRI scan shows a small amount of contrast between the posterior labrum and the glenoid, suggesting a posterior labral tear. The patient's symptoms are more consistent, however, with rotator cuff deconditioning because of the timing of his pain during the throwing motion and increased severity at the end of the game.

Treatment should focus on reconditioning of the rotator cuff and scapular stabilizers, combined with a return to throw program. Posterior labral tears are often found on MRI scans of asymptomatic throwers, and therefore, should not be considered the primary cause of a patient's symptoms unless it is supported by the history and physical examination. Internal rotation contractures can cause a similar pain pattern, but this patient has full and equal range of motion. The Preferred Response # 75 is 4.

 

76. A 7-year-old boy is referred to your office 3 months after jamming his finger while playing basketball. Examination reveals 40 degrees of active and passive motion at the proximal interphalangeal (PIP) joint. The PIP joint is stable to radial and ulnar stressing. Radiographs are shown in Figures 76a and 76b. What is the most appropriate management?

1. Observation

2. Corrective osteotomy

3. Ostectomy

4. Hand therapy for aggressive stretching 5- Dynamic splinting

 

DISCUSSION: The most appropriate management is an ostectomy, or resection of

the bone in the subcondylar fossa region. This is a malunion where the subcondylar fossa is blocked by malaligned bone. Because it is a bony block to motion, stretching or dynamic splinting will be of no benefit. The physis of the proximal phalanx is proximal,

 

making remodeling of a fracture at the distal end very unlikely. A corrective osteotomy has a risk of osteonecrosis of the very small distal fragment. The Preferred Res# 76 is 3.

 

77. A 27-year-old man sustains an injury in a fall while downhill skiing. Two days after injury he is seen by an orthopaedic surgeon and is diagnosed with a clavicle fracture. Examination and radiographs reveal 3 cm of shortening between the fracture fragments of the midshaft clavicle fracture. The surgeon has a discussion with the patient concerning surgical versus nonsurgical treatment. With regards to results, the patient is informed that they are similar concerning which of the following?

1. Nonunion rates

2. Infection

3. Shoulder range of motion 4- Shoulder strength

5- Shoulder rotational endurance

 

DISCUSSION: Shoulder range of motion is well maintained for both surgical and nonsurgical managment. Recent reports suggest that nonsurgical management of this fracture pattern may result in deficits of shoulder endurance and strength. Nonunion rates are significantly lower with surgical repair. Patient satisfaction, as determined by Constant scores, DASH, and patient-specific questionnaires, was higher with surgical intervention. Shoulder strength and rotational endurance are improved with surgical repair. The Preferred Response to Question # 77 is 3.

 

78. Figure 78 shows the clinical photograph of a patient who injured his finger while playing football. He cannot actively flex the distal interphalangeal joint of the ring finger. Which of the following is the most accurate statement regarding the injury shown?

1- The tendon is attached to the avulsed fragment from the distal phalanx. 2- There is no difference in time sensitivity in an acute injury

whether or not the tendon has retracted into the palm.

3- In a chronic (> 3 months) case of flexor digitorum profundus

(FDP) avulsion, the FDP should be tenodesed to the flexor digitorum sublimis (FDS). 4- If the FDP is advanced more than 1.5 cm, there is a risk for quadriga effect.

 

5- The method of repair does not affect repair gapping or strength of the tendon repair.

 

DISCUSSION: Overadvancement of the FDP tendon is one of the causes of the quadriga effect. Relative shortening of an FDP tendon decreases the excursion of the neighboring FDP tendons because they originate from a common muscle belly. The patient reports a weak grasp. Answer 1 is not correct because there can be a fracture and the tendon can avulse off of the fracture fragment (Trumble JHS-A 1992). Whether the tendon has retracted into the palm or not does matter because retraction into the palm allows pulleys to collapse and contract and it also means that the vinculae have been stripped off of the tendon. Regarding answer 3, in chronic cases where the FDS is intact and strong, many patients may be better off with a sublimis finger and no FDP reconstruction that could, in the worst case scenario, worsen a functional proximal interphalangeal joint. Regarding the repair method, there is recent research showing method of repair (button vs anchor), suture type, and method do affect the biomechanical properties of the repair. The Preferred Response to Question # 78 is 4.

 

79. What is the most common complication associated with the treatment of the distal biceps ruptures as shown in Figures 79a and 79b?

1. Re-rupture

2. Radioulnar synostosis

3. Posterior interosseous nerve injury

4. Lateral antebrachial cutaneous nerve irritation 5- Radial fracture

 

DISCUSSION: The patient shown underwent distal biceps repair with a button technique. Among the reports in the literature, the most commonly noted complication associated with this

technique is lateral antebrachial cutaneous nerve irritation. Re-rupture, radioulnar synostosis, and posterior interosseous nerve injury can occur, but are not as common as lateral antebrachial cutaneous nerve injury.The Preferred Response # 79 is 4.

 

80. A 16-year-old right-hand dominant male pitcher has had increasing pain in his dominant shoulder for the past 6 months without treatment. A coronal T2-weighted MRI scan is shown in Figure 80. What is the most appropriate treatment plan?

1. Decreased pitch count for 4 weeks

2. Continued play with close observation 3- Cessation of all throwing for 6 weeks 4- Arthroscopic repair

5- Mini-open repair

 

DISCUSSION: The coronal MRI scan shows an undersurface partial-thickness rotator cuff tear. Initial treatment for this injury should include complete cessation of throwing (or other overhead activities dependent on the athlete). Despite the duration of symptoms, he has had no treatment to date; therefore, nonsurgical management should include activity cessation, a rotator cuff and periscapular strengthening program, and then a slow and supervised return to throwing with particular attention to proper pitching mechanics. Decreasing the pitch count or continued play with observation risks progression of the problem. Surgical intervention is not indicated for initial treatment. The Preferred Response to Question # 80 is 3.

 

81. A 36-year-old woman reports vague right shoulder pain. She denies any previous shoulder problems or any recent trauma. MRI scans are shown in Figures 81a and 81b. Weakness of which of the following is the most likely finding in her physical examination?

 

1. Shoulder abduction and internal rotation

2. Shoulder external rotation and scapula protraction 3- Shoulder external rotation with the arm at the side 4- Shoulder internal rotation with the arm at the side 5- Scapula protraction

 

DISCUSSION: The MRI scans show a cyst formation within the suprascapular notch that can compress the suprascapular nerve. The suprascapular nerve innervates both the supraspinatus and the infraspinatus muscles. Therefore, patients with compression of

 

this nerve may demonstrate weakness of shoulder abduction and external rotation with the arm at the side. If the nerve is compressed after its innervation of the supraspinatus muscle, however, patients will demonstrate weakness of shoulder external rotation only. Suprascapular nerve does not innervate muscles that control scapula motion or shoulder internal rotation. The Preferred Response # 81 is 3.

 

82. A 61-year-old man reports right shoulder pain and loss of external rotation since having a seizure 5 months ago. MRI scans are shown in Figures 82a and 82b. What is the most appropriate treatment?

1- Closed reduction and application of a shoulder immobilizer 2- Open reduction and lesser tuberosity transfer

3- Hemiarthroplasty placed in anatomic version 4- Hemiarthroplasty placed in anteversion

5- Total shoulder arthroplasty

 

DISCUSSION: The patient has a chronic posterior shoulder dislocation with loss of approximately half of the humeral head. Hemiarthroplasty or osteochondral allograft to fill the defect would be required. Given the time since injury, the remaining native head and articular surface may have lost structural integrity, making hemiarthroplasty the preferred choice. The implant should be placed close to the patient's natural version, which normally is in the range of 20 to 30 degrees of retroversion. Excessive anteversion is not recommended to avoid repeat posterior dislocation. Closed reduction is highly unlikely to achieve a reduction and may cause displacement of an unrecognized humeral surgical neck fracture. Open reduction and lesser tuberosity transfer is best suited for smaller head defects and a less chronic dislocation. Glenoid integrity is not affected, thus a glenoid implant is unnecessary.

The Preferred Response to Question # 82 is 3.

 

83. A 17-year-old high school baseball player injured his dominant throwing arm sliding head first into third base. He has immediate pain and swelling along the medial aspect of the elbow and forearm, and demonstrates painful apprehension with any attempt at movement of the elbow. Radiographs of the elbow are shown in Figures 83a and 83b. What is the most appropriate management?

1. Cast immobilization for 6 weeks followed by rehabilitation

2. Hinged elbow brace for 6 weeks and initiation of early motion

3. Open reduction and internal fixation 4- Fragment excision

5- Closed reduction and percutaneous pinning

 

DISCUSSION: The patient has sustained a significantly displaced fracture of the medial epicondyle. Nonsurgical management is unlikely to restore valgus stability to the elbow necessary for overhead throwing. The fragment is large enough that bony stability should be achieved with rigid internal fixation, thereby allowing early range of motion and rehabilitation. Closed reduction attempts are unlikely to result in anatomic reduction, and pinning of a displaced fracture may put the ulnar nerve at risk. Fracture excision may further destabilize the elbow. The Preferred Response # 83 is 3.

 

84. A 51-year-old woman with shoulder pain responds transiently to a subacromial injection and physical therapy exercise program. When her symptoms recur, an arthroscopic subacromial decompression is recommended. During the surgery, a partial-thickness articular-sided supraspinatus tear is noted. The supraspinatus footprint is exposed for 3 mm from the articular margin. The remaining intra- articular structures are normal. Inspection from the bursal surface reveals the tendon to be intact. What is the most appropriate course of management?

1- Completion of the tear from the bursal surface and rotator cuff repair 2- Arthroscopic long head biceps tenotomy

3. Arthroscopic glenohumeral synovectomy

4. Arthroscopic tendon debridement and subacromial decompression 5- Transtendinous rotator cuff repair

 

DISCUSSION: The patient has a partial articular supraspinatus tendon avulsion (PASTA) lesion. Outcome studies suggest that articular-sided tears of this magnitude do well with arthroscopic decompression and debridement alone. Determination of lesion thickness is important in recommending treatment, and may be done with a variety of methods. Tears that involve exposure of less than 5 mm of the rotator cuff footprint likely measure less than half of the tendon thickness. In the absence of other associated pathology, bicipital tenotomy or synovectomy would be unnecessary.

Completion of the tear or transtendinous tear would be considered for lesions of greater than 50% thickness. The Preferred Response to Question # 84 is 4.

 

85. A 40-year-old man sustains a scapular body fracture after an all-terrain vehicle accident. Which of the following is the most commonly associated injury?

1. Chest injury

2. Clavicle fracture

3. Glenohumeral dislocation

4. Humeral fracture

5. Axillary nerve injury

 

DISCUSSION: Chest injury (rib fracture, pneumothorax, hemothorax, contusion) is the most commonly associated injury in patients who have sustained a significant scapular injury. Chest injury becomes even more commonly found when the scapula has more than one zone of injury (ie, multiple fractures). Humeral fracture, clavicle fracture, and axillary nerve injury are not as common as chest injury. The Preferred Respo# 85 is 1.

 

86. A 44-year-old woman with cubital tunnel syndrome and associated ulnar nerve subluxation with elbow flexion has failed to respond to nonsurgical management. Which of the following statements is most acccurate regarding in situ simple decompression of the nerve compared with subcutaneous anterior transposition? 1- Patients undergoing anterior transposition have improved motor outcomes.

2- Patients undergoing anterior transposition have improved sensory outcomes 3- Patients undergoing simple decompression have improved motor outcomes. 4- Patients undergoing simple decompression have improved sensory outcomes. 5- No differences in outcome are likely between treatment types.

 

DISCUSSION: Recent reports comparing outcomes of surgical treatment of ulnar nerve compression at the elbow have demonstrated no differences in outcome between simple decompression and anterior transposition. The presence of subluxation of the ulnar nerve was not a contraindication to in situ decompression in the study by Keiner and associates. The Preferred Response to Question # 86 is 5.

 

87. A 25-year-old electrician sustained an injury to his dominant arm while bench pressing at the gym. He reports that he felt a tearing sensation while extending his arms. Examination reveals that he has lost the normal contour of the axillary fold which worsens with resisted adduction. Additionally, there is extensive ecchymosis down the arm and weakness to adduction and internal rotation. Radiographs are normal. What is the most appropriate management?

1. Arthroscopic subscapularis repair

2. Repair of the long head of the biceps with tenodesis 3- Open repair of the pectoralis major tendon avulsion

4- Ultrasound and physical therapy to reduce swelling and improve strength 5- Brace immobilization for 6 weeks

 

DISCUSSION: This description is classic for an acute pectoralis major humeral avulsion. The loss of contour in the axillary fold confirms this diagnosis. Treatment for a pectoralis tendon avulsion should be open surgical repair in this young patient.

Therapy may be considered for injuries within the muscle or at the musculotendinous junction. Examination for subscapularis rupture and biceps injuries would not cause a change in the axillary fold. Bracing will not improve long-term strength.P R# 87 is 3.

 

88An otherwise healthy 30-year-old man undergoes right shoulder arthroscopic Bankart repair under regional anesthesia using an interscalene brachial plexus block. In the recovery room, he reports mild difficulty breathing and his chest radiograph shows a high riding diaphragm on the right side. His peripheral oxygenation is 97% on 2 liters of oxygen by nasal cannula. What is the most appropriate management? 1- Continued observation and monitoring

2. Obtain arterial blood gas measurements

3. Obtain emergent spiral CT scan to assess for pulmonary embolism

 

4. Insertion of a chest tube

5. Airway control and, if necessary, endotracheal intubation

 

DISCUSSION: Because the phrenic nerve lies in close proximity to the site of anesthetic injection, temporary hemidiaphragmatic paresis is a very common side effect of interscalene brachial plexus block. Pulmonary function and chest wall mechanics may be slightly compromised, but can easily be compensated in a healthy patient.

Therefore, with sufficient oxygenation, aggressive assessments or treatments such as arterial blood gas measurements, emergent spiral CT scans, chest tube insertions, or endotracheal intubation are not warranted. For this stable patient, continued monitoring with gradual withdrawal of oxygen is the most appropriate treatment.

The Preferred Response to Question # 88 is 1.

 

89. What is the interval used during an anterior approach (Henry) for a distal radius shaft fracture?

1- Flexor digitorum superficialis-flexor carpis ulnaris 2- Flexor carpi radialis-flexor digitorum superficialis 3- Brachioradialis-flexor carpi radialis

4- Flexor pollicis longus-flexor digitorum profundus 5- Flexor pollicis longus-flexor carpi radialis

 

DISCUSSION: The anterior approach to the radial shaft uses the internervous plane between the brachioradialis (radial n) and flexor carpi radialis (median n) distally, and the brachioradialis and pronator teres (median n) proximally. The Preferred Response to Question # 89 is 3.

 

90. A 37-year-old man with a nondisplaced radial neck fracture has failed to respond to 8 months of nonsurgical management. He has undergone extensive physical therapy and bracing without improvement. Examination reveals that active and passive range of motion is limited to 50 degrees to 85 degrees, with full pronosupination. He has mildly diminished sensation in the little and ring fingers.

Radiographs reveal healing of the fracture, no deformity, and no arthrosis or heterotopic bone formation. What is the most appropriate management?

 

1. Radial head resection and release of the anterior capsule

2. Anterior and posterior capsule release, with ulnar nerve transposition 3- Ulnar nerve transposition and release of the posterior capsule

4. Ulnar nerve transposition

5. Intra-articular corticosteroid injection

 

DISCUSSION: The patient has refractory extra-articular elbow stiffness and ulnar neuritis following trauma. Important considerations are ruling out failure of fracture healing, persistent deformity, and heterotopic bone formation. In this patient, further nonsurgical management is unlikely to provide any benefit; therefore, the treatment of choice is anterior and posterior capsule release, with ulnar nerve transposition. Radial head resection is not indicated because of the absence of deformity or arthrosis. There is restriction of both flexion and extension, so limited capsular release techniques will not maximize functional restoration. Ulnar nerve transposition alone will not restore motion. An intra-articular injection is not likely to improve motion 8 months after the injury. The Preferred Response to Question # 90 is 2.

 

91. Figure 91 shows the radiograph of a 57-year-old man who fell 6 feet off a ladder. He is neurovascularly intact but reports shoulder pain. What is the most appropriate acute treatment for this patient?

1- Physical therapy for range of motion, advancing to strengthening as tolerated 2- Sling immobilization and a recheck in 1 week with radiographs

3. CT scan of the shoulder

4. Open reduction and surgical stabilization with plates and screws

5. Ice, nonsteroidal anti-inflammatory drugs, and activity as tolerated

 

DISCUSSION: The patient has sustained a traumatic surgical neck fracture of the humerus. Sling immobilization and a recheck in 1 week with radiographs is appropriate

 

to check for maintenance of alignment. The fracture is minimally displaced and therefore does not require surgical stabilization or further diagnostic imaging. Surgical reduction and plating is not indicated in this nondisplaced fracture. Physical therapy and activity as tolerated at this point are contraindicated because of the acuity of the fracture. The Preferred Response to Question # 91 is 2.

 

92. What anatomic structure must be excised when performing a volar plate arthroplasty of the proximal interphalangeal joint?

1. Central slip

2. Collateral ligament

3. Checkrein ligament

4. Triangular ligament

5. Flexor digitorum superficialis insertion

 

DISCUSSION: The collateral ligament must be excised or released from the proximal phalanx to allow gliding of the middle phalanx on the articular surface of the proximal phalanx. Failure to do so may prevent this gliding motion and make the middle phalanx just hinge on the proximal phalanx. The Preferred Response to Question # 92 is 2.

 

93A 67-year-old woman with rheumatoid arthritis has had a 3-year history of gradually progressive right elbow pain and limited function despite intra-articular injections and medical management. She previously underwent a rheumatoid hand reconstruction, and has no pain or dysfunction of the ipsilateral shoulder.

Radiographs are shown in Figures 93a and 93b. What is the most appropriate treatment?

1. Soft-tissue interposition arthroplasty with radial head resection

2. Arthroscopic synovectomy with radial head resection 3- Elbow arthrodesis

4- Total elbow arthroplasty 5- Resection arthroplasty

 

DISCUSSION: Total elbow arthroplasty is the treatment of choice. The patient has end- stage rheumatoid involvement of the ulnohumeral and radiocapitellar joints. Given the advanced nature of the disease and evidence of bony erosion, arthroscopic synovectomy and interposition arthroplasty are unlikely to provide lasting benefit or functional improvement. Elbow arthrodesis and resection arthroplasty are considered salvage techniques and are generally not considered as a primary treatment method.

The Preferred Response to Question # 93 is 4.

 

94A 78-year-old woman undergoes an uneventful semiconstrained total elbow arthroplasty through a Bryan-Morrey approach. Her immediate postoperative management should include which of the following?

1. Five days of intravenous antibiotics for perioperative prophylaxis

2. Use of continuous passive motion beginning on postoperative day one

3. Immediate initiation of active flexion and gravity-assisted passive extension

4. Splinting at 60 to 90 degrees of flexion for 5 to 10 days, followed by initiation of active flexion and gravity-assisted passive extension

5. Splinting at 60 to 90 degrees of flexion until the triceps has healed, followed by initiation of active flexion and extension

 

DISCUSSION: Postoperative management of total elbow arthroplasty patients is directed to avoidance of complications commonly associated with this procedure. Following total elbow arthroplasty, 24 hours of perioperative antibiotics should be given, consistent with other arthroplasty procedures. Because of the relatively thin soft-tissue envelope surrounding the elbow, particularly in patients with rheumatoid arthritis, consideration must be given to the surrounding soft tissues postoperatively. The surgical wound should be given several days of quiescence prior to initiation of motion to minimize wound healing complications. Splinting at 60 to 90 degrees allows tension to be removed from the soft tissues. Immediate motion places these tissues under immediate stress; immobilization of the elbow for 6 to 8 weeks until the triceps has healed would result in significant stiffness. Splinting should not be used more than 10 days to avoid stiffness of the elbow.

The Preferred Response to Question # 94 is 4.

 

95. A 55-year-old man who underwent total shoulder arthroplasty 10 years ago recently reports an increase in shoulder pain. Laboratory studies consisting of a white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are all negative, as is joint aspiration. Radiographs are shown in Figures 95a and 95b. If all intraoperative frozen sections are negative, what is the appropriate treatment during revision surgery to provide pain relief and improved function?

1. Placement of antibiotic spacer

2. Removal of the glenoid, and possible bone grafting 3- Conversion to reverse shoulder arthroplasty

4- Referral to pain management 5- Shoulder arthrodesis

 

DISCUSSION: The radiographs reveal a loose glenoid in the setting of no infection. Glenoid removal may give this

patient the best chance of improved function and pain relief if sufficient bone stock remains. Bone grafting of defects may allow future glenoid implantation. Conversion to reverse shoulder arthroplasty would be a salvage procedure in this younger patient.

Shoulder arthrodesis would be difficult and unpredictable after shoulder arthroplasty. The Preferred Response # 95 is 2.

 

96. Which of the following clinical tests is used to diagnose medial instability of the elbow?

1- Posterolateral rotatory drawer test 2- Lateral pivot-shift test

3. Moving valgus stress test

4. Chair test (apprehension or dislocation on terminal extension of the supinated forearmwhen rising from a seated position)

5. Pushup sign

 

DISCUSSION: The moving valgus stress test is used in the diagnosis of medial collateral ligament instability of the elbow. The other tests apply a varus force to the elbow and are used to diagnose lateral ulnar collateral insufficiency. Preferred Respo# 96 is 3.

 

97Figures 97a and 97b show a clinical photograph and radiograph of a patient who has a history of repeated drainage from the lesion. What is the preferred surgical treatment?

 

1. Excision of the lesion alone

2. Removal of the osteophyte alone 3- Distal interphalangeal joint fusion

4. Excision of the mass and osteophyte removal

5. Removal of the mass and skin with skin grafting

 

DISCUSSION: The patient has a mucoid cyst. Whereas many of these lesions are associated with osteoarthritis, the best surgical treatment of the lesions in patients who have little or no pain is typically excision of the mass with osteophyte removal. Studies have shown that osteophyte excision helps minimize the risk of recurrence. Distal interphalangeal joint fusion is reserved for patients with pain and more advanced radiographic arthritis. Excision of the lesion alone is a less favorable option than excision of the mass and osteophyte removal. The lesion is independent of the skin and thus, skin removal with the mass is unnecessary.Preferred Respo# 97 is 4.

 

98. Isolated coronoid fractures are most likely related to what instability pattern? 1- Posterolateral rotary instability

2- Valgus anterolateral instability 3- Posterior instability

4- Varus posteromedial instability 5- Anterior instability

 

DISCUSSION: Coronoid fractures in the absence of radial head or associated fractures are often a sign of a varus posteromedial instability. Depending on the size of the coronoid fragment, fixation and stabilization of the coronoid may be necessary to restore medial stability of the elbow. Posterolateral instability is related to lateral ulnar collateral ligament incompetance. Anterior, valgus anterolateral, and posterior instability are not generally specific to isolated coronoid fractures. Pre Respo # 98 is 4.

 

99. A 35-year-old man has pain and swelling of his right, dominant wrist. Radiographs and MRI scans are shown in Figures 99a through 99d. What is the most appropriate management?

1. Incisional biopsy

2. Allograft reconstruction

3. Vascularized fibula reconstruction 4- Nonvascularized fibular autograft

5- Intralesional curettage and polymethylmethacrylate (PMMA) packing

 

DISCUSSION: Whereas the imaging studies show a benign giant cell tumor of bone, an incisional biopsy is still the first surgery that should be performed. After a tissue diagnosis is confirmed, then the reconstructive options can be discussed. A malignancy may present like a benign, aggressive giant cell tumor. Preferred Resp# 99 is 1.

 

100. A 27-year-old woman underwent shoulder arthroscopy for multidirectional instability 3 years ago. She was unable to regain shoulder range of motion despite therapy and has had progressively worsening pain. A current axillary radiograph is shown in Figure 100. In reviewing the medical records from the index procedure, what factor may be significant in contributing to her current condition?

 

1- Subsequent development of a supraspinatus tear 2- Subscapularis tendon dehiscence

3. Coagulation of the anterior humeral circumflex artery

4. Use of monopolar radiofrequency thermal capsulorrhaphy 5- Lack of compliance with postoperative therapy program

 

DISCUSSION: Reports from several centers suggest the potential to develop glenohumeral chondrolysis because of the heat production associated with use of radiofrequency or laser thermal capsulorrhaphy. A tear of the supraspinatus may lead to poor function and progression to rotator cuff tear arthropathy with superior humeral head migration. Subscapularis dehiscence is a risk in open surgery through a deltopectoral approach and can lead to anterior instability. The anterior humeral circumflex artery is the main supply to the humeral head and its coagulation can lead to osteonecrosis. Whereas a lack of postoperative therapy can lead to unresolved pain and stiffness, chondrolysis is not reported. The Preferred Response # 100 is 4.

 

101Which of the following structures cannot be seen during standard radiocarpal arthroscopy?

1. Scapholunate ligament

2. Lunotriquetral ligament

3. Radioscaphocapitate ligament 4- Extensor carpi ulnaris tendon

5- Superficial insertion of the triangular fibrocartilage complex (TFCC)

 

DISCUSSION: The extensor carpi ulnaris tendon is located in an extra-articular position, and as such, cannot be seen during arthroscopy. Wrist arthroscopy is a useful technique for evaluation and treatment of radiocarpal and midcarpal maladies. During standard radiocarpal arthroscopy, the scapholunate and lunotriquetral ligaments can be easily visualized. The superficial TFCC is seen overlying the ulnar head. Volarly, the radioscaphocapitate ligament can be seen as a discrete band of the capsule. The Preferred Response to Question # 101 is 4.

 

102An active 66-year-old man who underwent total shoulder arthroplasty 3 years ago now reports pain. Laboratory studies reveal an elevated erythrocyte sedimentation rate and C-reactive protein. Intraoperative frozen section reveals greater than 10 white blood cells per high power field on two slides and the Gram stain reveals gram-positive cocci in clusters. What is the most appropriate surgical treatment to eradicate the infection and maintain function?

 

1. Removal of the components and placement of an antibiotic spacer

2. Removal of the components, placement of an antibiotic spacer, and bone grafting of the glenoid defect

3. Resection arthroplasty

4. Exchange of the humeral head and debridement 5- Arthroscopic debridement

 

DISCUSSION: The prosthesis is grossly infected. Removal of the components and placement of an antibiotic spacer is necessary to eradicate the infection and allow for a second stage reimplantation. Resection arthroplasty is an option to treat the infection but the functional outcome would be limited. Bone grafting with concurrent infection is not likely to heal and should be delayed until the second stage. Humeral head exchange and debridement or arthroscopic debridement alone is unlikely to eradicate the infection. The Preferred Response to Question # 102 is 1.

 

103. A 77-year-old woman underwent semiconstrained right total elbow arthroplasty 4 weeks ago through a Bryan-Morrey approach. Her recovery was uneventful until 2 days ago when she began her physical therapy session at an outpatient clinic. During resisted extension exercises, she felt a "pop" in her elbow, accompanied with pain and inability to extend her elbow against resistance. What is the most likely cause of her symptoms?

1. Fracture of the ulnar component

2. Disengagement of the axle of the prosthesis 3- Failure of the triceps mechanism repair

4- Periprosthetic fracture of the humerus 5- Periprosthetic fracture of the ulna

 

DISCUSSION: During a Bryan-Morrey approach for total elbow arthroplasty, the triceps is dissected free from its ulnar insertion and reflected laterally. At the conclusion of the procedure, the triceps tendon is reattached to the ulna through drill holes. Whereas motion can be initiated postoperatively, 6 to 8 weeks of protection are recommended before initiation of resistance exercises to protect the triceps repair. A periprosthetic

 

fracture or component failure is rare in the absence of more significant trauma, and they are usually late complications. The Preferred Response to Question # 103 is 3.

 

104. A 47-year-old man who is right-hand dominant reports lateral-sided elbow pain after playing golf. His symptoms developed gradually and without trauma, and he has pain with gripping and repetitive movements with the hand and wrist.

Examination reveals his shoulder and wrist to be normal, and the elbow has no effusion and normal range of movement. He is tender near the lateral epicondyle, and symptoms are exacerbated with resisted wrist extension. Radiographs are shown in Figures 104a and 104b. What is the next most appropriate step in management?

1- Subtendinous epicondylar corticosteroid injection 2- Corticosteroid injection into the radial tunnel

3. MRI of the elbow

4. Percutaneous extensor carpi radialis brevis tenotomy

5. Physical therapy for an eccentric conditioning and strengthening program

 

DISCUSSION: The patient has lateral epicondylitis of relatively short duration. At this early stage of disease, nonsurgical management is indicated. An eccentric physical therapeutic exercise program has been shown to have a beneficial effect on tendon biology; therefore, it would be the most appropriate initial management. While the diagnosis of lateral epicondylitis may be confused with radial tunnel syndrome, the clinical examination and history are most suggestive of the former. Corticosteroid injection has been shown to help with symptoms in short-term follow-up, but does little to affect the natural progression of the condition; it is more appropriate as a

 

second line of treatment. MRI may be beneficial in patients with refractory disease and/or when the diagnosis is in question. Percutaneous surgical treatment is indicated only when nonsurgical measures fail to provide relief. The Preferred Respo# 104 is 5.

 

105. A 45-year-old woman has had a 4-month history of mild to moderate lateral shoulder pain that is aggravated with active elevation. Radiographs and MRI scans are shown in Figures 105a through 105d. Initial treatment should include which of the following?

1- Moist heat and a stretching program 2- Attempted calcium aspiration

3- Extracorporeal shock wave therapy 4- Low-dose radiation therapy

5- Arthroscopic rotator cuff debridement

 

DISCUSSION: The images show a well-circumscribed mass consistent with calcific tendinitis in the formation phase. Pain is not typically as severe as in the resorptive phase and amenable to nonsurgical management. The calcific deposit in this phase is granular, making aspiration difficult to achieve. Extracorporeal shock wave therapy has been studied with numerous protocols of amount of energy and number of treatments. Its role in the treatment of calcific tendinitis is still poorly defined. Low- dose radiation therapy has been successfully applied to calcific tendinitis in the past but is not currently used because of concerns of malignant tissue transformation and success with lower risk modalities. Arthroscopic debridement of the calcific deposit can be considered in patients who have not responded to nonsurgical management.

The Preferred Response to Question # 105 is 1.

 

106. A 62-year-old man has had worsening pain in the left shoulder for the past 6 weeks without trauma. He participated in physical therapy to "strengthen" his shoulder; however, it failed to provide relief. On examination, his right shoulder motion is 180, 60, and T8 (forward flexion, external rotation, and internal rotation). His left shoulder motion, both active and passive, is 150, 40, and L1. T1- and T2- weighted MRI scans are shown in Figures 106a and 106b with an official diagnosis of partial supraspinatus tendon tear. What is the appropriate treatment?

1- Physical therapy for rotator cuff strengthening and scapula stabilization 2- Regimen of stretching exercises for motion

3. Arthroscopic acromioplasty

4. Arthroscopic acromioplasty and rotator cuff repair 5- Open rotator cuff repair

 

DISCUSSION: The patient lacks both active and passive motion in all planes of shoulder motion; his primary pathology is adhesive capsulitis. Although the MRI scans reveal a partial-thickness rotator cuff tear, this is not uncommon in asymptomatic patients older than age 60 years. Physical therapy for patients with adhesive capulitis should stress shoulder motion rather than rotator cuff strengthening. Because most cases of adhesive capsulitis improve without surgical management, surgical treatment options are not appropriate at this time. The Preferred Response to Question # 106 is 2.

 

107. A 66-year-old woman with known poorly controlled rheumatoid arthritis reports that for the past 4 weeks she has been unable to extend the metacarpophalangeal (MCP) joints of her right hand index, middle, ring and little fingers. She cannot hyperextend the thumb interphalangeal joint. Active wrist extension is possible, but shows radial deviation. Examination reveals mild synovitis at the wrist and MCP joints of the affected hand. There is no ulnar deviation at the MCP joints with normal

alignment. When the MCP joints are passively extended, the patient is unable to maintain them in this position. There is no piano key sign at the distal ulna. Passive wrist motion shows a normal tenodesis effect. Which of the following would most likely confirm your diagnosis?

1. Radiographs of the hand

2. Radiographs of the cervical spine

3. Electrodiagnostic studies of the affected upper extremity 4- Surgical exploration of the extensor tendon ruptures

5- MRI of the elbow

DISCUSSION: There are many causes of inability to extend the MCP joints in a patient with rheumatoid arthritis. The most common cause is rupture of the extensor tendons. An intact tenodesis test suggests that the extensor tendons are intact, thus surgical exploration is not indicated and would not confirm the diagnosis. The patient has normal alignment of the fingers without ulnar deviation, suggesting that there are no MCP dislocations to account for the inability to extend the MCP joints; therefore, radiographs would not confirm the diagnosis. The most likely cause of inability to extend the fingers in this patient is posterior interosseous nerve (PIN) palsy.

Electrodiagnostic studies would confirm the presence of PIN palsy. An MRI of the elbow may show synovitis at the radiocapitellar joint, which can cause the PIN palsy. This finding however, is nonspecific and many patients without PIN palsy would also demonstrate synovitis at the radiocapitellar joint. Therefore, although an MRI would be helpful in localizing a potential cause of PIN compression, it would not in itself confirm the diagnosis. The Preferred Response to Question # 107 is 3.

 

108. A 23-year-old woman with recurrent anterior instability undergoes an open Bankart procedure. Six months after surgery the patient reports shoulder weakness and is concerned about instability of the shoulder joint. An MRI scan is shown in Figure 108. What is the most appropriate management?

1. Physical therapy

2. Biceps tenolysis

3. Subscapularis repair

4. Supraspinatus repair

5. Pectoralis major repair

 

DISCUSSION: The axial MRI scan shows rupture of the subscapularis tendon with dislocation of the biceps tendon. Treatment should include a biceps tenotomy or tenodesis in conjunction with a subscapularis repair. A pectoralis major transfer may be necessary in chronic cases where the subscapularis is irreparable, but in this patient the tendon is repairable. As a single operation, biceps tenolysis will not correct the instability, and would likely result in a cosmetic deformity. Physical therapy will not restore subscapularis function. The Preferred Response to Question # 108 is 3.

 

109. A patient has a mass at the base of the middle finger just distal to the distal palmar flexion crease. The mass is 2 mm in size, firm, round, and does not move with finger motion. It is painful with gripping activites such as a steering wheel. What is the most appropriate management?

 

1. Diagnostic ultrasound

2. MRI

3. Needle aspiration

4. Observation

5. Surgical excision

 

DISCUSSION: The clinical scenario is of an A2 retinacular cyst. These are firm round cysts arising from the pulley system so they do not move with tendon motion. Needle aspiration in the office is highly effective, thus surgery can be avoided. Based on the clinical diagnosis, ultrasound and MRI are unnecessary. Because the patient has pain and functional limitations, observation is not recommended. The Prefer Resp# 109 is 3.

 

110A 72-year-old woman was evaluated with an MRI scan for a shoulder mass that was confirmed to be a lipoma. Additional MRI findings included a 7-mm full- thickness tear of the supraspinatus tendon. Therefore, the patient was referred by her internist for evaluation and management of the rotator cuff tear. The patient reports mild "stiffness" with certain motion but denies any limitations in her functional capacity. Examination reveals a slight decrease in internal rotation and mild weakness with resisted abduction of the shoulder. What is the most appropriate management?

 

1. Observation

2. Arthroscopic rotator cuff debridement

3. Arthroscopic rotator cuff repair with acromioplasty 4- Arthroscopic biceps tendon tenotomy

5- Open rotator cuff repair with bone tunnels

 

DISCUSSION: In patients older than age 60 years, over 30% of asymptomatic shoulders show MRI findings of full-thickness rotator cuff tears. Therefore, without significant symptoms, surgical treatment is not warranted. The Preferred Response# 110 is 1.

 

111A baseball player reports a dull pain in the posterior aspect of his throwing arm. Examination reveals decreased internal rotation and prominence of the inferomedial corner of the scapula. An MRI scan suggests a partial-thickness tear of the posterior supraspinatus tendon. Successful treatment would most likely include which of the following?

 

1. Anti-inflammatory medication, posterior capsular stretching, and rotator cuff strengthening

2. SLAP repair

3. Debridement of the partial-thickness rotator cuff tear 4- Rotator cuff repair

5- Imbrication of the labrum and anterior capsule

 

DISCUSSION: Internal impingement is related to an internal rotation contracture (GIRD- glenohumeral internal rotation deficit) and an increase in external rotation caused by repetitive overhead throwing. Most patients can be successfully treated with rehabilitation that focuses on internal rotation stretches along with anti-inflammatory medication and strengthening as symptoms improve. SLAP repair and rotator cuff debridement may be considered in refractory cases. Rotator cuff repair is not typically required, and capsulolabral imbrication is more consistent with the surgical treatment for multidirectional instability.

The Preferred Response to Question # 111 is 1.

 

112Figures 112a and 112b show the radiographs of a 28-year-old motorcyclist who sustained a closed hand injury in a collision. What is the most appropriate definitive treatment?

1- Closed reduction and a hand/forearm cast in the intrinsic plus position 2- Closed reduction and a hand splint

3. Primary fusion of the carpometacarpal joints

4. Closed versus open reduction and internal fixation 5- Closed reduction and external fixation

 

DISCUSSION: Closed versus open reduction and internal fixation is the most appropriate treatment. The radiographs show fracture-dislocations of all five carpometacarpal joints. These injuries are extremely unstable and not amenable to closed (splint or cast) treatment only. External fixation may be warranted in an open, contaminated injury. Fusion would be an option if this were a chronic, painful condition on presentation. The Preferred Response to Question # 112 is 4.

 

113A 32-year-old male hockey player who is right-hand dominant was checked from behind and landed with full force into the boards. In the emergency department he reports shortness of breath. Figure 113 shows a 2-D CT scan. What is the best initial treatment for this injury?

1. Observation

2. Closed reduction with a towel clip 3- Open reduction

4. Open reduction and internal fixation

5. Open reduction and sternoclavicular ligament allograft reconstruction

 

DISCUSSION: The CT scan shows a posterior sternoclavicular joint dislocation. Initial management involves attempted closed reduction in the operating room. This can be performed with a towel clip and anterior translation of the displaced clavicle. However,

 

the orthopaedic surgeon should be prepared to open this injury and reconstruct the joint if necessary. Furthermore, it is recommended that a thoracic surgeon be available prior to beginning these procedures. Open reduction should be done only if closed reduction is unsuccessful. The Preferred Response to Question # 113 is 2.

 

114What additional procedure should be done when performing a radioscapholunate fusion for posttraumatic arthrosis following a distal radius fracture?

1- Excision of the triquetrum and distal pole of the scaphoid 2- Anterior interosseous neurectomy

3- Fascial interposition arthroplasty of the capitolunate joint 4- Sectioning of the dorsal intercarpal ligament

5- Ulnar shortening osteotomy

 

DISCUSSION: Excision of the triquetrum and distal pole of the scaphoid frees up the mid-carpal joint, improving radial deviation and the flexion-extension arc of motion of the wrist. This offers an alternative to complete wrist arthrodesis for posttraumatic arthrosis of the radiocarpal joint. An anterior interosseous neurectomy is believed to decrease some pain transmission from the wrist but because the fusion is done dorsal, cutting this volar structure is not routinely done. Fascial interposition is not needed because the capitolunate should be preserved in posttraumatic radiocarpal arthrosis. Sectioning of the dorsal intercarpal ligament would provide no benefit. If the triquetrum is excised, then an ulnar shortening osteotomy is unnecessary. The Preferred Response to Question # 114 is 1.

 

115A 72-year-old man who underwent an uncomplicated total shoulder arthroplasty 4 weeks ago now reports injuring his shoulder in a fall on the ice. He attempted to catch himself on a railing with his operative arm. He continues to feel pain anteriorly in the shoulder. His range of motion is 140 degrees forward elevation, 90 degrees external rotation with the arm at the side, and internal rotation up the back to L1.

Radiographs are normal. What is the most likely diagnosis? 1- Deltoid contusion

2. Rupture of the subscapularis repair

 

3. Traumatic loosening of the glenoid

4. Locked posterior shoulder dislocation 5- Biceps tendon rupture

 

DISCUSSION: The patient sustained a rupture of the subscapularis tendon repair. This can occur in the postoperative period with forced internal rotation or excessive external rotation beyond the normal 40 to 60 degrees. On examination, the patient has 90 degrees of external rotation at the side; this is not a normal finding for a 72-year-old man. There is no indication at this time that the glenoid component has loosened or that the patient has a locked posterior dislocation. Both of these would be evident on radiographs. A biceps tendon rupture or a deltoid contusion would not explain the excessive external rotation to 90 degrees as seen on examination. The Preferred Response to Question # 115 is 2.

 

116. A 68-year-old man with a history of diabetes and total shoulder arthroplasty 4 years ago, now reports increasing shoulder pain and stiffness. Radiographs show lucent lines around both the humeral and glenoid components. Laboratory studies show a white blood cell count of 12,600/mm3, an erythrocyte sedimentation rate of 72 mm/h, and a c-reactive protein of 3.5. The shoulder is aspirated and cultures are negative at 3 days. What is the most appropriate treatment for this patient?

1- 4-week trial of nonsteroidal anti-inflammatory drugs (NSAIDs) 2- Physical therapy for range-of-motion work

3. Repeat aspiration and culture

4. Open irrigation and debridement with implant removal and possible exchange arthroplasty

5. Arthroscopic irrigation and debridement

 

DISCUSSION: The patient has clinical and radiographic signs of infection. Open debridement, component removal, an antibiotic spacer, and possible exchange arthroplasty are necessary to resolve the infection. Aspiration and culture can often be negative at 3 days. NSAIDs, sling immobilization, or physical therapy are not indicated. With radiographs indicating lucent lines surrounding the prosthetic implants,

 

arthroscopic irrigation and debridement will not eradicate the infection. The Preferred Response to Question # 116 is 4.

 

117. A 35-year-old construction worker sustained a midshaft clavicle fracture that developed a hypertrophic nonunion. One year after the injury, it was internally fixed without bone graft. Four months after the surgery he was asymptomatic and he was released to full activity. Five months following surgery, the patient was digging a ditch and he felt pain in the clavicle. The 4-month and 5-month postoperative radiographs are shown in Figures 117a and 117b. What is the most likely cause of this failure?

1- Iliac crest bone graft was not used to augment the fixation 2- Infection

3. Inadequate strength of the plate

4. Use of superior plating rather than anterior plating 5- Inadequate medial screw fixation

 

DISCUSSION: In this patient, the hardware was intact for 5 months without any evidence of loosening prior to the catastrophic failure. This suggests that the primary cause of nonunion was poor biology rather than insufficient fixation. Biologic compromise can be caused by either infection, poor blood supply, or lack of osteogenic induction cells. Iliac crest bone graft has been used by some for any nonunion of the clavicle, but two studies have shown that bone graft is not necessary to achieve union. Rigid fixation is all that is required. Infection will still complicate any fixation technique. The radiographs show unicortical screw fixation medially, but the construct did not loosen; therefore, it is not the cause of failure.

The Preferred Response # 117 is 2.

 

118. A 60-year-old woman with a history of osteoporosis fell from a standing height and sustained a supracondylar distal humerus fracture with an intercondylar extension. Which of the following plate constructs yields the highest stiffness for fixation of the fracture?

1. Single posterior Y plate

2. Single medial plate with bicortical locking screws

3. Dual plating with medial and posterolateral LC-DCP

4. Dual plating with medial and posterolateral one third tubular plates 5- Dual plating with medial and lateral LC-DCP

 

DISCUSSION: Optimal treatment of distal humeral fractures relies on reestablishment of a congruent articular surface with a fixation construct that is stable enough to allow for early range of motion. Several biomechanical studies have been performed to evaluate the biomechanical strength of various plating configurations. These studies have shown that dual plate configurations are more stable than single plates, regardless of the type of plate used. One third tubular plates have been shown to be significantly weaker than LC-DCP or reconstruction plates, resulting in weaker constructs, and clinically higher rates of hardware failure and nonunion. Whereas traditional teaching has suggested plating in perpendicular planes, recent biomechanical studies have demonstrated that parallel medial and lateral plates confer a greater rigidity to the construct than perpendicular plating schemes. The Preferred Response to Question # 118 is 5.

 

119. A 35-year-old construction worker continues to have weakness with lifting overhead 2 years after he was treated with physical therapy for a "chest muscle" tear. An obvious deformity noted in his axilla worsens with resisted extension and adduction. A clinical photograph and MRI scan are shown in Figures 119a and 119b. What is the most appropriate treatment?

 

1- Allograft reconstruction with semitendinosis weave to the humerus 2- Latissimus dorsi tendon transfer

3. Electrical stimulation

4. Shoulder arthrodesis

5. Arthroscopic pectoralis major tendon repair

 

DISCUSSION: This scenario describes a chronic, symptomatic pectoralis major tendon rupture in a young laborer. Direct repair is difficult at this time; therefore, allograft reconstruction is a good alternative to recover strength. Tendon transfers, electrical stimulation, shoulder arthrodesis, and arthroscopy are not indicated in this patient. They will not offer proper reconstruction of the lost muscle tendon unit and/or cosmetic repair. The Preferred Response to Question # 119 is 1.

 

120. A 74-year-old patient is seen for follow-up 6 weeks after undergoing a total shoulder arthroplasty for glenohumeral osteoarthritis. The patient missed the 2- week follow-up appointment and is currently wearing a sling. The incision is well healed with no signs of breakdown. Examination reveals that passive range of motion is forward elevation of 90 degrees, external rotation at the side 0 degrees, and internal rotation up the back is to the level of the greater trochanter. A radiograph shows no signs of fracture or dislocation. What is the next most appropriate management for this patient?

1- Physical therapy for range-of-motion exercises 2- Aspiration for possible infection

3. MRI to evaluate for possible rotator cuff tear

4. Sling immobilization and reevaluation in 4 weeks

5. Duplex ultrasound for possible upper extremity deep venous thrombosis

 

DISCUSSION: The patient has a postoperative stiff shoulder. The patient missed follow- up appointments and has not been participating in physical therapy for stretching.

Based on normal radiographic findings, the shoulder is not dislocated; therefore, physical therapy should begin immediately. Continued sling immobilization will further worsen the stiffness. There is no indication of an infection or rotator cuff tear. Deep

 

venous thrombosis would present with abnormal swelling and pain. The Preferred Response to Question # 120 is 1.

 

121. A 22-year-old man sustained a shoulder dislocation while playing collegiate football at age 18. Since that time, he has dislocated the shoulder three more times despite physical therapy. His last dislocation occurred 4 weeks ago while sleeping. What is the most appropriate management for this patient?

1. Corticosteroid injection

2. Changing the physical therapist to an athletic trainer

3. A 1-month trial of nonsteroidal anti-inflammatory drugs (NSAIDs) 4- Shoulder immobilization for 6 weeks

5- A discussion regarding surgical stabilization procedures

 

DISCUSSION: The patient sustained a traumatic shoulder dislocation at age 18 that has subsequently failed to respond to nonsurgical management. Discussion of surgical stabilization procedures is warranted at this time. A corticosteroid injection or a trial of NSAIDs will not provide any stabilizing effect. Further immobilization in this patient population has not been shown to improve stability.Prefer Respons# 121 is 5.

 

122. While performing a total shoulder arthroplasty, excessive retraction is placed on the "strap muscles" (short head of biceps and coracobrachialis). Neurovascular examination would reveal weakness of which of the following?

1. Shoulder abduction

2. Shoulder external rotation 3- Shoulder internal rotation 4- Elbow extension

5- Forearm supination

 

DISCUSSION: The musculocutaneous nerve can be as close as 3 cm to the coracoid process; therefore, this relationship is important to keep in mind when performing surgery in this area. Excessive traction on the musculocutaneous nerve could lead to a neurapraxia with resultant weakness of elbow flexion and forearm supinaton because of the loss of biceps function. The Preferred Response to Question # 122 is 5.

 

123With the arm abducted 90 degrees and fully externally rotated, which of the following glenohumeral ligaments resists anterior translation of the humerus? 1- Coracohumeral ligament

2- Superior glenohumeral ligament 3- Middle glenohumeral ligament

4- Anterior band of the inferior glenohumeral ligament complex 5- Posterior band of the inferior glenohumeral ligament complex

 

DISCUSSION: With the arm in the abducted, externally rotated position, the anterior band of the inferior glenohumeral ligament complex moves anteriorly, preventing anterior humeral head translation. Both the coracohumeral ligament and the superior glenohumeral ligament restrain the humeral head to inferior translation of the adducted arm, and to external rotation in the adducted position. The middle glenohumeral ligament is a primary stabilizer to anterior translation with the arm abducted to 45 degrees. The posterior band of the inferior glenohumeral ligament complex resists posterior translation of the humeral head when the arm is internally rotated. The Preferred Response to Question # 123 is 4.

 

124. Which of the following statements regarding the use of thermal shrinkage during arthroscopic shoulder surgery is most accurate?

1. The amount of shrinkage is fixed for a given peak temperature, irrespective of the time of application.

2. Denatured capsular tissue does not undergo a healing response.

3. The capsule is typically found to be thick and fibrotic in revision cases following thermal shrinkage.

4. Patients with good results at 1 year are unlikely to develop recurrent instability in the future.

5. High failure rates have been reported in its use for anterior, posterior, and multidirectional instability.

 

DISCUSSION: Reports of clinical results at 2- and 5-year follow-up indicate much higher failure rates than traditional stabilization techniques for all common instability patterns. The degree of capsular shrinkage is dependent on the total amount of

 

thermal energy delivered, as well as the rate of delivery. Denatured tissue undergoes a healing response. The capsule typically encountered in revision cases is thin and patulous, rather than thick and fibrotic. The Preferred Response to Question # 124 is 5.

 

125. A 54-year-old man with a history of diabetes mellitus underwent internal fixation for a humeral shaft nonunion 8 months ago. His postoperative course had been unremarkable. However, over the past few weeks, he reports mild pain with activity. At rest, he has no pain. He denies any recent fevers or chills. Radiographs are shown in Figures 125a and 125b. What is the next most appropriate step in management?

1- CT scan of the humerus to confirm the nonunion 2- Application of a functional fracture brace

3. Laboratory evaluation

4. Removal of hardware and intramedullary fixation 5- Revision internal fixation with a plate

DISCUSSION: Radiographs showing broken hardware (screw head) and the clinical history are consistent with fracture nonunion; therefore, a CT scan is not required. Treatment for this nonunion may include various options including functional fracture bracing, intramedullary fixation, or revision internal fixation. However, prior to any treatment, infection must be eliminated as a cause for the nonunion. Evaluation for infection can include laboratory studies such as erythrocyte sedimentation rate and C- reactive protein level. The Preferred Response to Question # 125 is 3.

 

Question 1 A 30-year-old man has a painful ankle mass. Radiographs are seen in Figures 1a and 1b, and MRI scans are seen in Figures 1c and 1d. What is the most likely diagnosis?

1. Synovial hemangioma

2. Synovial sarcoma

3. Lipoma arborescens

4. Synovial chondromatosis

5. Pigmented villonodular synovitis

 

DISCUSSION: The calcified loose bodies shown on the imaging studies are characteristic of synovial chondromatosis. Pigmented villonodular synovitis and lipoma arborescens do not show calcifications. Synovial sarcoma and synovial hemangioma can mineralize but they tend to be more diffuse, and not associated with loose bodies. Synovial sarcoma is rarely intra-articular. Preferred Res # 1 is 4.

 

Question 2 Figures 2a through 2d show the radiographs, MRI scan, and bone scan of a 44-year-old man who twisted his knee and felt a pop. Following the injury he had swelling; however, both the pain and swelling have now resolved. What is the next most appropriate step in the management of the patient's distal femoral lesion?

 

1. Radiographic follow-up

2. Biopsy

3. Surgical resection

4. Radiation therapy

5. Chemotherapy

 

DISCUSSION: The lesion seen on the radiographs and MRI scan is consistent with an enchondroma. Enchondromas are commonly encountered by orthopaedic surgeons as an incidental finding during evaluation of a patient for pain of other causes.

Enchondromas are painless, show no aggressive bone destruction, and commonly exhibit radiotracer uptake on a bone scan. Surgery for enchondromas is not generally necessary, but when clinical and radiographic features suggest a potential chondrosarcoma, action is necessary. Chondrosarcoma almost always occurs in adults. Patients usually present with pain and have characteristic findings on staging studies. Lucencies developing within the calcification, periosteal reaction, and an associated soft-tissue mass all are characteristic features of chondrosarcoma.

Biopsies are not typically indicated because of the histologic similarity of benign and malignant cartilage lesions. Radiographic follow-up is appropriate when the clinical suspicion of chondrosarcoma is low. In this patient, the bone lesion was discovered incidentally because of unrelated trauma and the patient is essentially asymptomatic with benign-appearing radiographic features.Preferred Res # 2 is 1.

 

Question 3 Figures 3a through 3e show the radiographs and MRI scans of a 16- year-old boy. Which of the following best describes features of the patient's tumor?

1. Telomere translocations

2. Supernumerary ring chromosomes

3. A translocation involving genes 11 and 22

4. A rearrangement involving the X and 18 chromosomes

5. Genetic alterations in the retinoblastoma gene and p53 tumor suppressor gene

 

DISCUSSION: The imaging studies show a classic case of conventional high-grade osteosarcoma. Genetic alterations in the retinoblastoma gene and p53 tumor suppressor gene are common in this tumor. A translocation involving chromosomes 11 and 22 is characteristic of Ewing's sarcoma. Supernumerary ring chromosomes

 

are seen in parosteal osteosarcoma. Telomere translocations have been described in giant cell tumor of bone. A translocation of chromosomes X and 18 is typical of synovial sarcoma. The Preferred Response to Question # 3 is 5.

 

Question 4 A 12-year-old girl has a 6-month history of a painful expanding mass in the right lateral ankle. A clinical photograph, radiograph, MRI scans, and histology specimens are seen in Figures 4a through 4f. What is the most appropriate management?

1. Resection alone

2. Resection and chemotherapy

3. Resection and radiation therapy

4. Chemotherapy and radiation therapy 5- Observation

 

DISCUSSION: The radiograph shows an expansile radiolucent lesion without matrix production or a periosteal reaction. On close inspection, there are subtle internal septations on the mortise view. The MRI scans show heterogeneous septated areas with prominent fluid-fluid levels. The histopathology on low power shows villous projections and prominent clefts, whereas the high power view reveals prominent spindled stromal cells and interspersed multinucleated giant cells. This is an aneurysmal bone cyst. The treatment of aneurysmal bone cyst is generally intralesional surgery (eg, curettage). However, for patients with large destructive lesions in expendable bones such as the fibula, excision is preferred. The main differential diagnosis in this patient is telangiectatic osteosarcoma. Radiographs of telangiectatic osteosarcoma show geographic bone lysis, a wide zone of transition, and matrix mineralization. Under the microscope, telangiectatic osteosarcoma exhibits pleomorphic cells with at least focal malignant osteoid production.

Telangiectatic osteosarcoma is treated with chemotherapy and wide excision. The Preferred Response to Question # 4 is 1.

 

Question 5 Figures 5a and 5b show the AP radiograph and axial CT scan of an 18- year-old woman who has proximal thigh pain. What is the most appropriate treatment?

1. Observation

2. Curettage and grafting

3. Radiofrequency ablation

4. Wide resection

5. Wide resection and chemotherapy

 

DISCUSSION: The imaging studies are classic for osteoid osteoma, a benign lesion. Conventional treatment has involved burring down to find the lesion, followed by curettage. More recent experience with radiofrequency ablation under CT guidance has shown equivalent results with few complications. Curettage in

this location would carry significant morbidity and risk for fracture, making radiofrequency ablation the most appropriate treatment. More aggressive resections are not indicated because the lesion has a low chance of recurrence. Observation and/or use of nonsteroidal anti-inflammatory drugs would be reasonable if the patient is willing to live with prolonged pain. The Preferred Response to Question # 5 is 3.

 

Question 6 What are the five soft-tissue sarcomas that can frequently metastasize to the lymph nodes?

1. Synovial sarcoma, angiosarcoma, osteosarcoma, chondrosarcoma, Ewing's sarcoma

2. Chondrosarcoma, osteosarcoma, fibrosarcoma, Ewing's sarcoma, adamantinoma

3. Rhabdomyosarcoma, synovial sarcoma, epithelioid sarcoma, clear cell sarcoma, angiosarcoma

4. Myxoid chondrosarcoma, fibrosarcoma, malignant peripheral nerve sheath tumor, liposarcoma, malignant fibrous histiocytoma

5. Rhabdomyosarcoma, myxoid liposarcoma, acral mxyoinflammatory fibroblastic sarcoma, synovial sarcoma, epithelioid sarcoma

 

DISCUSSION: When sarcomas spread, they classically metastasize to the lung. Their second most common site to metastasize to is either another bone or soft tissue, depending on whether it is a primary bone or soft-tissue sarcoma. Regional

metastases are relatively a rare occurrence - only about 5% of patients with soft- tissue sarcomas. The incidence is slightly higher in patients with rhabdomyosarcoma, synovial sarcoma, epithelioid sarcoma, clear cell sarcoma, or angiosarcoma. In these patients, consideration for sentinel node biopsy should be given. The Preferred Response to Question # 6 is 3.

 

Question 7 A 36-year-old man has had an enlarging left posterior thigh soft-tissue mass for the past month, and he now reports numbness and tingling in his sciatic nerve distribution. Based on the MRI scan and biopsy specimen shown in Figures 7a and 7b, what is the most likely diagnosis?

 

1. Myxoid liposarcoma

2. Synovial sarcoma

3. Malignant fibrous histiocytoma 4- Fibrosarcoma

5- Well-differentiated liposarcoma

 

DISCUSSION: Most soft-tissue sarcomas have a similar MRI appearance and cannot be differentiated by signal intensity characteristics. Histologic and often immunohistochemical analysis is necessary to subtype soft-tissue sarcomas. Myxoid liposarcomas account for one half of all liposarcomas, with a peak incidence during the fifth decade. Myxoid liposarcomas have a characteristic histologic appearance with myxoid background and an interlacing network of fine vessels. The delicate plexiform capillary vascular network is present throughout these tumors and provides an important clue for distinguishing them from myxomas. Treatment consists of wide surgical resection. Synovial sarcomas have a monophasic or biphasic histologic pattern. Malignant fibrous histiocytoma (undifferentiated pleomorphic sarcoma) is composed of pleomorphic cells in a storiform pattern. Fibrosarcoma has a typical "herringbone" pattern on low power histology. Well-differentiated liposarcoma has bland histology of adipocytes with scattered lipoblasts. The Preferred Response to Question # 7 is 1.

 

Question 8 An otherwise healthy 15-year-old boy is seen in the emergency department for an injury sustained while playing dodge ball. A radiograph is shown in Figure 8. What is the most appropriate treatment for this patient?

 

1. Aspiration and injection

 

2. Resection and reconstruction 3- Sling and pain medication

4- Curettage and bone grafting 5- Intramedullary nail fixation

 

DISCUSSION: The patient has a pathologic fracture through a benign-appearing eccentric bone lesion with a soap-bubble geographic appearance, most suggestive of a nonossifying fibroma. The best initial treatment is to provide comfort measures and allow the fracture to heal. Aspiration and steroid injection has been advocated for a unicameral bone cyst, though it should be done after any associated fracture has been allowed to heal. Wide resection is not indicated for this benign tumor Extended curettage and grafting may be appropriate, but only after fracture healing has occurred unless open reduction and internal fixation is indicated for the fracture itself. Intramedullary nail fixation is unnecessary and generally should not be performed if the histopathologic diagnosis is not known. The Preferred Resp # 8 is 3.

 

Question 9 A 7-year-old boy has a 3-week history of neck pain. History and physical examination reveal no neurologic symptoms. A radiograph, CT scan, and MRI scans are seen in Figures 9a through 9d. Figure 9e shows a needle biopsy specimen. Based on these findings, what is the most appropriate management?

1. Cervical collar and observation

2. Intravenous antibiotics and cervical collar 3- Chemotherapy and radiation therapy

4. Neoadjuvant chemotherapy alone

5. Neoadjuvant chemotherapy and surgical resection

 

DISCUSSION: The findings are consistent with eosinophilic granuloma. Eosinophilic granuloma is a focal destructive lesion of bone commonly seen in children younger than age 10 years. Despite the very aggressive appearance of these lesions, they

 

typically will heal spontaneously or following biopsy. Local corticosteroid injection has been advocated by some. Surgical decompression is indicated in rare cases of cord compression. Chemotherapy is indicated only in disseminated forms of histiocytosis. The Preferred Response to Question # 9 is 1.

 

Question 10 A 12-year-old boy is diagnosed with osteosarcoma of the left distal femur. The lesion measures 7 cm in its greatest dimension and is associated with a soft-tissue mass that extends into the vastus lateralis. A CT scan of the chest is normal. A bone scan reveals another lesion in the contralateral right proximal femur. Biopsy of the right proximal femur lesion also reveals osteosarcoma.

According to the American Joint Committee on Cancer (AJCC), what is the stage of this tumor?

1- II-A 2- II-B 3- III 4- IV-A 5- IV-B

 

DISCUSSION: The AJCC staging system for bone sarcomas is based on tumor grade, size, and the presence as well as location of metastases. Stage I tumors are low grade. Stage II tumors are high grade. Stages I and II are subdivided based on size. Stages I-A and II-A are less than or equal to 8 cm in their greatest linear measurement. Stages I-B and II-B are greater than 8 cm in size. Stage III tumors are those that have "skip metastases" which are defined as discontinuous lesions within the same bone. Stage IV-A involves pulmonary metastases, whereas stage IV-B includes patients with non-pulmonary metastases; therefore, the stage of this tumor would be IV-B. The Preferred Response to Question # 10 is 5.

 

Question 11 A 28-year-old woman has a painless mass on the dorsum of the foot that has been rapidly increasing in size over the last 3 months. It measures 5.7 cm in maximum diameter. A lateral radiograph of the foot is shown in Figure 11a.

Sagittal T1-weighted and coronal T2-weighted MRI scans are shown in Figures 11b and 11c. A photomicrograph from the biopsy specimen is shown in Figure 11d. The most appropriate surgical treatment would likely include which of the following?

 

1. Intralesional excision

2. Marginal excision and split-thickness skin grafting 3- Aspiration and antibiotics

4- Wide resection and flap coverage 5- Below-knee amputation

 

DISCUSSION: The clinical presentation, imaging studies, and histology are consistent with a high-grade soft-tissue sarcoma. The MRI scans show a heterogeneous lesion. Histology demonstrates a spindle cell lesion with pleomorphism, atypica, and large bizarre mitoses. Treatment of soft-tissue sarcomas should include at least a wide resection. Intralesional or marginal excision is not advised for high-grade sarcoma. Below-knee amputation is an option for this patient, but most likely limb-sparing procedures for this particular sarcoma would be possible and also more functional while also allowing proper oncologic surgical resection. On this area of the dorsum of the foot, split-thickness skin grafting would likely have a higher failure rate than a fasciocutaneous flap over the tendons. Whereas aspiration of a fluid-containing cystic lesion (ganglion cyst) would be appropriate, it is not appropriate for this solid, heterogeneous lesion. The Preferred Response to Question # 11 is 4.

 

Question 12 Figures 12a and 12b show the radiographs of a 22-year-old man who reports left knee pain. An MRI scan is seen in Figure 12c, and a photomicrograph is seen in Figure 12d. What stage is this lesion according to the Enneking staging system?

1. I

2. II

3. III

4- 1

5- 2

 

DISCUSSION: The radiographs show a purely radiolucent lesion in the distal femur with no cortical destruction. There is no soft-tissue extension noted on the MRI

 

scan. The photomicrograph demonstrates multiple giant cells with a background of mononuclear cells, confirming the diagnosis of giant cell tumor. This lesion is classified as a stage 2 (benign active) tumor according to the Enneking staging system. Using this system, malignant tumors are staged using Roman numerals, and benign tumors are staged using Arabic numerals. Stage 1 tumors are "latent." Stage 2 tumors are "active," and stage 3 tumors are "aggressive." Whereas some giant cell tumors are stage 3, the lesion in this patient does not demonstrate particularly aggressive imaging features, such as cortical breakthrough and soft-tissue extension. The Preferred Response to Question # 12 is 5.

 

Question 13 A 9-year-old boy with a history of unilateral retinoblastoma has a 2- week history of left arm pain. His mother, who had bilateral retinoblastoma, noted a mass on his left proximal arm 2 days prior to the office visit. A radiograph, MRI scan, and biopsy specimen are seen in Figures 13a through 13c. What is the most appropriate treatment?

 

1. Observation

2. Wide resection

3. Radiotherapy and wide resection 4- Chemotherapy and wide resection 5- Extended curettage and bone grafting

 

DISCUSSION: The radiograph and MRI scan show an aggressive lesion in the left proximal humerus in a child with a history of retinoblastoma. The biopsy specimen shows pleomorphic spindled cells with focal osteoid. There is a well-documented association between retinoblastoma and osteosarcoma because it has been found that most, if not all, such tumors have defects in their RB1 pathway through genetic lesions in the RB1 gene itself or other genes in the pathway. Linkage analysis at the retinoblastoma gene (RB1) locus is required for identification of individuals at risk of developing retinoblastoma and osteosarcoma. Identification of disease-causing mutations is necessary for accurate risk prediction. The treatment for osteosarcoma is chemotherapy and surgery, either wide local resection or amputation.

Radiotherapy is not a useful adjunct in the treatment of osteosarcoma. Chemotherapy and wide resection is the preferred treatment. The Preferred Response to Question # 13 is 4.

 

Question 14 An otherwise healthy teenager has an isolated lower extremity mass. The biopsy of the mass reveals the diagnosis of rhabdomyosarcoma. Management of the patient's mass should consist of which of the following?

1. Hemipelvectomy amputation

2. Wide resection, chemotherapy, and radiation therapy 3- Wide resection and radiation therapy

4. Marginal excision

5. Observation

 

DISCUSSION: Treatment of rhabdomyosarcomas includes wide resection of the primary tumor, chemotherapy, and radiation therapy. Rhabdomyosarcomas are one of the soft-tissue sarcomas where chemotherapy has been shown to have a substantial survival benefit. In all cases without a radical margin, radiation therapy should also be added to the treatment plan. Amputation is rarely needed for local tumor control and is typically selected when an amputation provides better functional results than a limb-sparing procedure. Observation of these tumors is rarely, if ever, indicated. Sentinal node biopsy may be indicated in these patients if there is clinical or radiographic node enlargement. The Preferred Respon # 14 is 2.

 

Question 15 A 28-year-old man has had left shoulder pain for 1 year. The pain is constant and has steadily worsened over time. History reveals that he underwent curettage for a "noncancerous bone tumor" 5 years ago. A radiograph, bone scan, MRI scan, and biopsy specimens are shown in Figures 15a through 15e. What is the most appropriate treatment for this patient?

1. Wide resection alone

2. Resection and chemotherapy

3. Intralesional curettage and grafting 4- Forequarter amputation

5- Radiation therapy and prophylactic internal fixation

 

DISCUSSION: The radiographs and histology are consistent with a clear cell chondrosarcoma. The treatment is wide resection. No chemotherapy is indicated because this is a locally aggressive tumor with minimal risk of metastasis.

Intralesional curettage may be appropriate for a benign bone tumor but not for a clear cell chondrosarcoma. Amputation and radiation therapy are not indicated to achieve local disease control. This case illustrates the occasional problems with diagnosis of this tumor. The Preferred Response to Question # 15 is 1.

 

Question 16 A 45-year-old man has a 6-month history of a leg mass and recent ulceration of the skin. The clinical photograph and biopsy specimen are seen in Figures 16a and 16b. What is the most likely diagnosis?

1- Ewing's sarcoma/peripheral primitive neuroectodermal tumor 2- Extraskeletal myxoid chondrosarcoma

3. Dermatofibrosarcoma

4. Myxoid/round cell liposarcoma 5- Synovial sarcoma

 

DISCUSSION: Dermatofibrosarcoma is a rare, monoclonal, cutaneous sarcoma arising in the dermis in the trunk, 47%; lower extremity, 20%; upper extremity, 18%; and head and neck, 14%. Symptoms may be present for a duration of 6 months to 30 years. It may occur at any age, with a peak incidence in the fourth decade; it is more common in men than women (3:2). Most tumors are superficial and less than 5 cm, but 3% are larger than 10 cm. They present early as pink or violet-red plaques surrounded by telangiectatic skin. A nodular growth pattern with ulceration and attachment to deeper structures is observed in advanced and/or recurrent cases.

Most cases (85% to 90%) are low grade but (5% to 15%) contain focal, high-grade fibrosarcomatous areas with intermediate-grade tumor (DFSP-FS). MRI is useful in ascertaining tumor extent and depth of invasion. Tumor cells exhibit a storiform growth pattern and infiltrate adjacent adnexal structures and adipose tissue.

Fibrosarcomatous transformation can occur over time and is recognized by

 

increased mitotic activity. Because some tumors express platelet derived growth factor, they may be responsive to imatinib. Ewing's sarcoma, extraskeletal myxoid chondrosarcoma, liposarcoma, and synovial sarcoma are generally deep-seated tumors that can but very rarely cause skin ulceration. The Preferred Resp# 16 is 3.

 

Question 17 An otherwise healthy 52-year-old man has had a several year history of a slowly enlarging, symptomatic left shoulder, axillary, and chest wall mass.

Radiographs are only remarkable for a large soft-tissue mass. Selected sequences of MRI scans are shown in Figure 17a (T1), Figure 17b (T2 fat saturated), and Figure 17c (T1 fat saturated post-gadolinium). Management of this symptomatic mass should consist of which of the following?

1. Forequarter amputation

2. Wide resection, chemotherapy, and radiation therapy 3- Wide resection and radiation therapy

4. Marginal excision

5. Incisional biopsy

 

DISCUSSION: The MRI scans show a large soft-tissue mass that is iso-intense with subcutaneous fat of all sequences. This is diagnostic of a lipocytic (fatty) tumor- either lipoma, atypical lipomatous tumor, or low-grade liposarcoma. As such, no biopsy is necessary because biopsies of these fatty tumors can be fraught with sampling error. The most appropriate treatment of this symptomatic lesion is simple, marginal excision without radiation therapy or chemotherapy. Local recurrence can occur in 25% to 50% of patients at 10 years. Dedifferentiation is rare with subsequent recurrent disease; but when it occurs, it may result in metastases. The Preferred Response to Question # 17 is 4.

 

Question 18 Tumoral calcinosis is a hereditary disease that involves which of the following?

1. Calcium metabolism

2. Phosphate metabolism

3. Oxalate metabolism

4. Chloride metabolism

5. Renal tubular insufficiency

 

DISCUSSION: Although not completely understood, the phosphate metabolic dysfunction seen in tumoral calcinosis is a hereditary disease. This is characterized by soft-tissue lesions that are calcified, lobulated, well-demarcated lesions usually found over the extensor surfaces of large joints. It is most commonly found around the hip, elbow, shoulder, foot, and wrist joints. Renal tubular insufficiency is associated with acidosis, glucosuria, phosphaturia, aminoaciduria, and mild proteinuria. Oxalate metabolism can contribute to calcium oxalate crystals and kidney stones. Oxalate is found in many food products. Calcium metabolism, which can be abnormal in renal insufficiency, hypervitaminosis D, and milk-alkali syndrome, is normal in tumoral calcinosis. Metabolic alkalosis is often associated with a alteration in chloride metabolism. The Preferred Response # 18 is 2.

 

Question 19 A 25-year-old man has a painful mass in a web space of his foot. MRI scans are seen in Figures 19a (T2 STIR) and 19b (T1), a representative gross specimen is seen in Figure 19c, and a H&E stain is seen in Figure 19d. What is the most likely diagnosis?

1. Melanoma

2. Synovial sarcoma

3. Interdigital neuroma

4. Epithelioid sarcoma

5. Giant cell tumor of tendon sheath

 

DISCUSSION: Giant cell tumors of tendon sheath are common in the hands and feet. Because of significant hemosiderin deposition, they commonly appear hypointense to skeletal muscle on both T1 and T2 pulse-weighted sequences. The hemosiderin is manifested in the brownish discoloration in the gross specimen. The photomicrograph shows bland spindled stromal cells and abundant multinuclear giant cells. Treatment is marginal excision with relatively low rates of tumor recurrence. Although the foot is not an infrequent site of melanoma and there are some shared radiologic features with giant cell tumor of tendon sheath, histologically melanoma is composed of cells both spindled and epithelioid arranged in nests or clusters. Synovial sarcoma is the most common sarcoma of the foot which radiographically has mineralizations in 30% of cases. It is typically heterogeneous on both MR pulse sequences. Microscopically, monophasic synovial sarcoma contains spindled cells that are arranged in short intersecting fascicles similar to fibrosarcoma. Pseudoglandular areas can be observed in biphasic cases.

Epithelioid sarcoma, though common in the hand, is relatively rare in the foot and is histologically distinct from giant cell tumor of tendon sheath. When this tumor secondarily involves bone, it may be confused with osteomyelitis.

 

Pref Res# 19 is 5.

 

Question 20 Osteofibrous dysplasia and adamantinoma are both rare tumors of bone generally occurring in the tibia. Which of the following histologic findings is typically seen only in adamantinoma?

 

1- Biphasic pattern of glandular epithelial cells surrounded by spindle cells 2- Bone trabeculae with osteoblastic rimming and fibrous stroma

3. Bone trabeculae without osteoblastic rimming within fibrous stroma

4. Multinucleated giant cells with background stromal cells with similar nuclei 5- Herringbone pattern with pleomorphic cells

 

DISCUSSION: A biphasic pattern of glandular epithelial cells surrounded by fibrous spindle cells is the distinguishing histologic feature of an adamantinoma. The other choices are the histologic patterns seen with osteofibrous dysplasia, fibrous dysplasia, giant cell tumor, and fibrosarcoma, respectively.

 

Preferred Res# 20 is 1.

 

Question 21 A 7-year-old boy has multiple firm, fixed masses about his knees and extremities. Occasionally he has pain when he bumps his knee or around his proximal legs when he is playing soccer. Radiographs are shown in Figures 21a and 21b. A CT scan of the distal femurs is shown in Figure 21c. What is the next most appropriate step in management?

 

1. Observation

2. Biopsy of the largest lesions 3- Whole body PET scan

4- Removal of all lesions about the knee 5- Bisphosphonate therapy

 

DISCUSSION: The patient's clinical presentation and imaging studies are diagnostic of multiple hereditary exostoses (MHE). Whereas removal of symptomatic osteochondromas is indicated if symptoms are severe enough, biopsy of the lesions or removal of all of the lesions is not indicated. Currently, a PET scan does not have a defined role in the evaluation of MHE patients. Bisphosphonate therapy currently has no defined role in the treatment of MHE patients. These patients are best observed if asymptomatic, and the development of symptoms or masses that grow after skeletal maturity should be evaluated for possible malignant degeneration of these lesions.

 

The Preferred Response to Question # 21 is 1.

 

Question 22 A 24-year-old woman has had a mass on her right shoulder for the past 3 months. The mass is intermittently painful, warm, and swollen, particularly after periods of activity. Rest and ice relieve her symptoms. Radiographs are normal. T1-, T2-weighted, and contrast-enhanced MRI images are shown in Figures 22a through 22c. What is the most likely diagnosis?

1. Synovial cell sarcoma

2. Carcinoma metastatic to soft tissue

3. Muscle tear with hematoma formation 4- Abscess

5- Intramuscular hemangioma

 

DISCUSSION: The lesion is an intramuscular hemangioma. Imaging characteristics can appear quite aggressive, and sarcoma is often in the differential. Fat is a prominent feature in diagnosing these tumors. In addition contrast aids in demonstrating the vascular channels, particularly in cavernous subtype. No necrosis or rim enhancement is demonstrated and no appreciable mass effect is noted, making malignancy or abscess less likely. A muscle tear with hematoma formation could have a similar appearance, but the time course should have allowed for partial or complete hematoma resolution. Observation is generally the treatment of choice, but if symptoms are not relieved by noninvasive means, surgery, sclerotherapy, and sometimes embolization may have a role. The Preferred Response # 22 is 5.

 

Question 23 What syndrome is associated with the presence of enchondromas and hemangiomas?

1. Maffucci's syndrome

2. Hunter's syndrome

3. Multiple hereditary exostoses 4- Ollier's disease

5- Trevor's disease

 

DISCUSSION: Maffucci's syndrome is characterized by the presence of enchondromas and hemangiomas. Ollier's disease is multiple enchondromatosis. Multiple hereditary exostoses is characterized by the presence of multiple exostoses

 

not associated with skin lesions or endocrine abnormalities. Hunter's syndrome is a mucopolysaccharidosis and lysosomal storage disease that affects all large joints with pain and decreased range of motion. Trevor's disease is an epiphyseal osteochondroma. The Preferred Response to Question # 23 is 1.

 

Question 24 A 4-year-old boy has a 3-month history of limping and pain in the right tibia. According to his parents, he has frequent night pain. There is no history of weight loss, fevers, or night sweats. Examination reveals that the left tibia is moderately tender to palpation. There is no palpable mass or lymphadenopathy. Radiographs, MRI scans, and biopsy specimens are seen in Figures 24a through 24f. What is the fusion protein frequently associated with this disorder?

1. SYT-SSX

2. ASPL-TFE3

3. EWS-ATF1

4. EWS-FLI1

5. TLS-CHOP

 

DISCUSSION: The permeative changes and "onion skin" periosteal reaction with no observable matrix production on radiographs are suspicious for Ewing's sarcoma. The cells are small, round, and monotonous on low power and have large hyperchromatic nuclei and indistinct cytoplasmic borders on high power, supporting the diagnosis of Ewing's sarcoma. Molecular analysis confirmed the EWS-FLI1 mutation. The radiographic differential diagnosis includes: osteomyelitis, Langerhans cell histiocytosis, and lymphoma. EWS-ATF1 is associated with clear cell sarcoma, while ASPL-TFE3 is associated with alveolar soft part sarcoma. SYT-SSX and TLS- CHOP are associated with synovial sarcoma and liposarcoma, respectively. The Preferred Response to Question # 24 is 4.

Question 25 A 15-year-old girl is referred for evaluation of a tibial lesion noted on radiographs performed after a twisting injury of the left knee. She was asymptomatic prior to the injury that occurred 3 weeks ago. The pain from the injury has now resolved. Radiographs of the left knee are seen in Figures 25a and 25b. What is the next step in management of this patient?

1. CT

2. MRI

3. Bone scan

4. Needle biopsy

5. Observation

 

DISCUSSION: The radiographs reveal a benign-appearing lesion of the proximal tibia metaphysis with a

narrow zone of transition, an eccentric position, and a thin rim of reactive bone. The imaging characteristics are most consistent with nonossifying fibroma. These lesions may occur multiply in 8% of patients. Most lesions are eccentric with a "soap bubble" appearance and may have significant cortical thinning. Pathologic fractures may occur. This lesion was discovered as an incidental finding. Because the patient is asymptomatic, no further work-up or treatment is indicated except for observation. Most lesions resolve spontaneously by adulthood. The Preferred Response # 25 is 5.

 

Question 26 A 13-year-old girl injured her left shoulder playing volleyball. The shoulder was previously asymptomatic. She was referred for evaluation of a left humeral lesion noted on radiographs obtained after the injury. Currently she has returned to playing volleyball and is asymptomatic again. AP and lateral radiographs of the shoulder are seen in Figures 26a and 26b. What is the next most appropriate step in management of this patient?

 

1. MRI

2. CT

3. Bone scan

4. Needle biopsy

5. Observation

 

DISCUSSION: The radiographs reveal an osteochondroma of the left humerus; therefore, no further work-up is needed. The lesion was found as an incidental finding after an injury and since it is asymptomatic, no further treatment is needed except for observation. An MRI scan or a CT scan could be obtained to evaluate the thickness of the cartilaginous cap if a secondary chondrosarcoma is suspected in an enlarging lesion in an adult. These studies could also be obtained to define anatomic relationships if surgery is planned. A bone scan could be used to identify other lesions but would not likely provide useful information for this patient. Needle biopsy would not provide any useful information. The Preferred Response # 26 is 5.

 

Question 27 A 55-year-old woman with a history of lung cancer who underwent resection 1 year ago now reports thigh pain. Radiographs are shown in Figures 27a and 27b. A CT scan of the chest, abdomen, and pelvis and a bone scan show no other lesions. What is the most appropriate next step in management?

 

1. Chemotherapy

2. External fixation

3. Reamed intramedullary nail with reamings sent to pathology

4. Biopsy

5. External beam radiation followed by placement of an intramedullary nail

 

DISCUSSION: The radiographs show a lytic lesion that is highly suggestive of metastatic cancer in this clinical setting. However, in this patient with no other bone lesion as demonstrated by bone scan, a primary sarcoma or myeloma cannot be excluded. Therefore, biopsy should be done prior to prophylactic stabilization to avoid inadvertently contaminating the entire femur. Sending reamings during the intramedullary nailing is not an acceptable method of performing a biopsy on an indeterminate lesion. Chemotherapy, radiation, nailing, or external fixation should not be performed prior to establishing a diagnosis. The Preferred Resp # 27 is 4.

 

Question 28 Which of the following is the most common soft-tissue sarcoma of the hand?

1. Chondrosarcoma

2. Rhabdomyosarcoma

3. Epithelioid sarcoma

4. Myxoid liposarcoma

5. Hemangiopericytoma

 

DISCUSSION: The hand is a rare location for soft-tissue sarcomas. The most common histologic subtypes seen there are epithelioid sarcoma, malignant fibrous histiocytoma, synovial sarcoma, and clear cell sarcoma. The Preferred Res# 28 is 3.

REFERENCES: Pradhan A, Cheung YC, Grimer RJ, Peake D, Al-Muderis OA, Thomas

 

Question 29 A 70-year-old man has a painful leg mass. The mass has been present for many years and has not changed in size. It is exquisitely tender to palpation.

MRI scans are seen in Figures 29a through 29c, and a biopsy specimen is seen in Figure 29d. What is the most likely diagnosis?

1. Lipoma

2. Fibrosarcoma

3. Neurofibroma

4. Synovial sarcoma

5. Giant cell tumor of tendon sheath

 

DISCUSSION: Exquisite tenderness is a hallmark of benign nerve sheath tumors. The MRI scans show a well-defined soft-tissue mass within the posterior tibial nerve. The histology is consistent with a neurofibroma and characterized by hypocellularity and "rope-like" or wavy collagen bundles. The MRI scan findings are not consistent with a lipoma. The histology is not consistent with fibrosarcoma (characterized by hypercellularity, atypia, and "herringbone" growth pattern), giant cell tumor of

 

tendon sheath (monomorphic stromal cells, hemosiderin-laden macrophanges, and giant cells), synovial sarcoma (hypercellular, monophasic or biphasic epithelioid cells), or lipoma (bland lipocytes). The Preferred Response to Question # 29 is 3.

 

Question 30A 10-year-old boy has had increasing left knee pain for the past 4 months. AP and lateral radiographs of the left proximal tibia are seen in Figures 30a and 30b. An MRI scan and biopsy specimen are seen in Figures 30c and 30d. What is the most appropriate treatment for this patient?

1. Surgery and chemotherapy

2. Surgery and radiation therapy

3. Radiation therapy and chemotherapy 4- Surgery alone

5- Radiation therapy alone

 

DISCUSSION: The imaging studies demonstrate an aggressive-appearing blastic lesion of the proximal tibial metaphysis. This is highly suggestive of osteosarcoma. The biopsy specimen reveals malignant spindle cells that produce osteoid, thus confirming the diagnosis of osteosarcoma. Treatment of osteosarcoma is multimodal including multi-agent chemotherapy and surgery (wide resection or amputation). Radiation therapy is not used in the initial curative treatment of osteosarcoma. The Preferred Response to Question # 30 is 1.

 

Question 31 A 72-year-old woman reports pain with overhead activity. Examination reveals a prominent mass near the inferior angle of the scapula. A CT scan is shown in Figure 31a and a biopsy specimen is shown in Figure 31b. What is the most likely diagnosis?

1. Lipoma

2. Lymphoma

3. Hemangioma

4. Elastofibroma

5. Giant cell tumor of tendon sheath

 

DISCUSSION: Although elastofibromas can occur anywhere in the body, the most common location is the ventral aspect of the scapula. The CT scan shows a mass anterior to the left scapula and overlying the chest wall with strands of low attenuation representing fat. The biopsy specimen shows a pauci-cellular disease process with dense collagen and elastin fibers. The dark staining areas represent elastin. Lipomas generally are homogeneous with low attenuation on CT. Lymphoma has a fairly uniform small round cell morphology microscopically. Hemangiomas may have mineralizations (phleboliths) on radiographs and CT and microscopically reveal multiple capillary or cavernous vascular spaces with intervening fat. On histologic sections, giant cell tumor of tendon sheath is a spindle cell proliferation with interspersed giant cells and hemosiderin-laden macrophages.

Pre Res# 31 is 4.

 

Question 32 A 46-year-old man has a 2-month history of an enlarging medial arm mass. Representative MRI scans and a biopsy specimen are shown in Figures 32a through 32c. What is the genetic abnormality associated with this type of soft- tissue tumor?

1- t(11;22)

2- t(X;18)

3- t(12;16)

4- t(2;13)

5- t(12;22)

 

DISCUSSION: The images demonstrate a deep, heterogenous mass with histology showing a typical biphasic pattern seen with synovial sarcoma. Synovial sarcoma is characterized by t(X;18), which leads to the formation of a fusion gene between the SYT on chromosome 18 and one of the adjacent genes on the X chromosome, SSX1 or SSX2. Using RT-PCR, it is possible to detect the SYT-SSX fusion transcript. A characteristic t(11;22) occurs in Ewing's sarcoma. This is the most studied solid tumor chromosome translocation. This rearrangement leads to juxtaposition of a gene, designated EWSR1, on chromosome 22 with FLI1 gene on chromosome 11.

Myxoid liposarcoma is characterized by the presence of t(12;16). Most alveolar rhabdomyosarcoma cells exhibit t(2;13). t(12;22) has been associated with clear cell sarcoma.

The Preferred Response to Question # 32 is 2.

 

Question 33 Figures 33a through 33c show the MRI scans and biopsy specimen of a 9-year-old girl who has had progressive swelling and a mass on her medial elbow for 1 month. The area is increasingly painful to touch and with range of motion.

The remainder of her examination is unremarkable. What is the next most appropriate step in management?

1. Chemotherapy

2. Radiation therapy

3. Antibiotic therapy

4. Observation

5. Physical therapy

 

DISCUSSION: Cat scratch disease (CSD) is typically a benign and self-limited illness lasting 6 to 12 weeks in the absence of antibiotic therapy. Regional lymphadenopathy (axillary, epitrochlear, inguinal) is the predominant clinical feature of CSD; affected nodes are often tender and occasionally suppurate. Between 25% and 60% of patients report a primary cutaneous inoculation lesion (0.5- to 1-cm papule or pustule) at the site of a cat scratch or bite. The skin lesions typically develop 3 to 10 days after injury and precede the onset of lymphadenopathy by 1 to 2 weeks. Bartonella henselae is now regarded as the etiologic agent of CSD. For many years, CSD has been clinically diagnosed when three of the following four criteria are met in a patient: 1) history of traumatic cat contact; 2) positive skin-test response to CSD skin-test antigen; 3) characteristic lymph node lesions; and 4) negative laboratory investigation for unexplained lymphadenopathy. Treatment consists of azithromycin, ciprofloxacin, doxycycline, or multiple other antibiotics, all of which have been used successfully. Radiation therapy and chemotherapy would be reserved for malignant diseases and would not be appropriate in this setting.

Treatment is necessary for this infectious entity; therefore, observation or physical therapy is not indicated. The Preferred Response to Question # 33 is 3.

 

Question 34 Figures 34a through 34d show the AP and lateral radiographs, MRI scan, and biopsy specimen of a 45-year-old man who has had pain for 3 months. Immumohistochemistry shows CD99 negativity. What is the most likely diagnosis? 1- Lymphoma of bone

2. Ewing's sarcoma

3. Chondrosarcoma

4. Metastatic adenocarcinoma

5. Osteogenic sarcoma

 

DISCUSSION: Lymphoma is a destructive lesion of bone, often with a large soft-tissue mass. Histology shows basophilic cells of varying size with little background stroma. Ewing's sarcoma histology also shows uniform sheets of small blue round cells, but typically occurs in childhood and shows CD99 positivity on immunohistochemistry.

Chondrosarcoma demonstrates malignant cartilage, adenocarcinoma demonstrates a glandular arrangement of epithelial cells, and osteogenic sarcoma is a mixed lytic/blastic lesion demonstrating malignant cells producing immature osteoid. The Preferred Response to Question # 34 is 1.

 

Question 35 A 45-year-old woman has a slowly enlarging mass over the radial aspect of her middle finger at the level of the proximal interphalangeal joint. It is associated with decreased flexion of the joint and clinically is fixed to the underlying bone. Radiographs reveal erosion of the lateral cortex of the proximal phalanx. Gross observation at the time of surgery reveals that the mass has a yellowish-brown tint and lobulated areas. Histology demonstrates bland fibrous stroma with scattered histiocytes, giant cells, and hemosiderin. What is the most likely diagnosis?

 

1. Epithelioid sarcoma

2. Giant cell tumor of tendon sheath 3- Gouty tophus

4. Hemangioma

5. Epithelial inclusion cyst

 

DISCUSSION: The clinical and pathologic description is typical of a giant cell tumor of tendon sheath. Epithelioid sarcoma is the most common soft-tissue sarcoma in the hand and is composed of a nodular arrangement of tumor cells with epithelioid appearance and eosinophilia with a tendency to undergo central degeneration and

 

ulceration. Gouty tophi have a characteristic white, chalky gross appearance and will demonstrate negatively birefringent crystals on polarized light microscopy.

Hemangiomas are composed of a variable amount of fat and vessels. Epithelial inclusion cysts are filled with keratin from desquamation of the hyperkeratotic, stratified squamous epithelial cells that line the cysts. The Preferred Resp# 35 is 2.

 

Question 36 Figures 36a through 36e show the AP and lateral radiographs, axial CT scan, sagittal MRI scan, and biopsy specimen of an 18-year-old man with knee pain. What is the most likely diagnosis?

 

1. Fibrous dysplasia

2. Osteoblastoma

3. Osteosarcoma

4. Nonossifying fibroma

5. Osteomyelitis

 

DISCUSSION: The most likely diagnosis is osteoblastoma, which has a widely varied radiographic appearance. It can often best be described as a large osteoid osteoma (> 1 to 2 cm). It can be lytic or blastic, but is usually well-marginated, indicating its benign nature. Histology shows trabecula with intermixed nonmalignant osteoblasts. Osteoid osteoma is a small (< 1 to 2 cm) lesion with thick sclerotic bone surrounding a small lytic nidus. Histology is very similar to osteoblastoma.

Osteosarcoma has malignant cells seen on histology. Nonossifying fibroma is an eccentric lytic lesion occurring in the metaphysis and has a bland fibrous background arranged in a storiform pattern with scattered giant cells under the microscope.

Osteomyelitis tends to be partially lytic often with a draining sinus or overlying skin changes. Fibrous dysplasia is characterized by ground glass calcification and a chinese character pattern on histology. The Preferred Response # 36 is 2.

 

Question 37 Which of the following is associated with local recurrence following excision of the lesion shown in Figures 37a through 37c?

1. Age of patient

2. Effectiveness of chemotherapy 3- Tumor necrosis

4- Sensitivity to radiation 5- Type of graft material

 

DISCUSSION: The lesion shown in the images is an aneurysmal bone cyst. These lesions are known to have a local recurrence rate of 5% to 50%. Young age, open physes, stage, and type of surgical removal and resulting margin have all been shown to affect the recurrence rate. Chemotherapy and radiation are not used in the treatment of aneurysmal bone cysts. The percentage of necrosis of the lesion is prognostic in osteosarcoma. The type of graft material does not affect local recurrence. The Preferred Response to Question # 37 is 1.

 

Question 38 Figures 38a through 38c show the radiographs and CT scan of a 24- year-old man who reports tightness in the left knee and decreased range of motion. A biopsy specimen is shown in Figure 38d. What is the most appropriate treatment plan?

1- Radiation therapy and surgical resection 2- Chemotherapy and surgical resection

3- Chemotherapy, radiation therapy, and surgical resection 4- Surgical resection only

5- Observation

 

DISCUSSION: Parosteal osteosarcoma is a well-differentiated malignant tumor arising on the surface of the bone. It comprises less than 5% of all osteogenic sarcomas. It is amenable to surgical resection alone. A number of reports have confirmed that parosteal osteosarcoma has a better prognosis than other osteosarcomas. Histologic features are a bland fibroblastic stroma intermixed with well-developed bony trabeculae. Radiation therapy and chemotherapy have no role in the treatment of low-grade parosteal osteosarcoma. Observation is not appropriate for this lesion. The Preferred Response to Question # 38 is 4.

 

Question 39 A 63-year-old man has had increasing left leg pain over the last several months. History reveals that he has had recurring cyclic pain in the leg for the past several years. Radiographs show an enlarged, sclerotic tibia, with thickened coarse trabeculae and varus bowing. What is the most appropriate management for this patient?

1. Vitamin D

2. Calcium supplement

3. Methotrexate

4. Nonsteroidal antiinflammatory drugs (NSAIDs) 5- Bisphosphonate therapy

 

DISCUSSION: Based on the signs and symptoms, Paget's disease is the most likely diagnosis. In Paget's disease, an elevated alkaline phosphatase level and high output heart failure may be seen. Hearing loss can be seen when there is involvement of the skull, and malignant degeneration is uncommon but recognized as a risk.

Patients are often treated with bisphosphonate medications during the active disease process to help control osteoclastic activity and pain. Vitamin D and calcium are more appropriate for treatment of osteoporosis. Methotrexate is not indicated for the treatment of Paget's disease. NSAIDs may be helpful to treat pain associated with Paget's disease but will not alter the clinical course. The Preferred Res # 39 is 5.

 

Question 40 Radiographs of the right knee of a 21-year-old man are seen in Figures 40a and 40b. What is the inheritance pattern of this disorder?

 

1. Sporadic

2. Autosomal dominant

3. Autosomal recessive

4. X-linked dominant

5. X-linked recessive

 

DISCUSSION: The radiographs show multiple osteochondromas and are thus diagnostic for multiple hereditary exostoses (MHE). MHE is

an autosomal-dominant disorder with greater than 95% penetrance. It is associated with mutations of the EXT1 or EXT2 genes. In addition to multiple osteochondromas, affected individuals typically exhibit short stature and angular deformities of the long bones. The Preferred Response to Question # 40 is 2.

 

Question 41 A 57-year-old woman has a right proximal humerus lesion that was originally discovered when a chest radiograph was obtained. The right shoulder is asymptomatic. An AP radiograph of the right shoulder is seen in Figure 41. What is the next step in management?

 

1. MRI

2. CT

3. Bone scan

4. Biopsy

5. Observation

 

DISCUSSION: The radiograph shows a benign-appearing lesion with stippled calcification. There is no cortical erosion. Equally important is the fact that the patient is asymptomatic. These findings are typical of enchondroma. No further work-up is indicated for this patient except for observation with serial radiographs. If the patient has symptoms, further cross-sectional imaging may be necessary to assess the aggressiveness of the lesion. A bone scan will differentiate monostotic disease from polyostotic disease and the relative uptake may help assess activity. Biopsy is usually not helpful in distinguishing between enchondromas and low-grade chondrosarcomas. The Preferred Response to Question # 41 is 5.

 

Question 42 Giant cell tumor of the tendon sheath is histologically most closely related to which of the following?

1. Desmoplastic fibroma

2. Dermatofibroma

3. Pigmented villonodular synovitis (PVNS) 4- Myositis ossificans

5- Epithelial inclusion cyst

 

DISCUSSION: A giant cell tumor of the tendon sheath consists of multinucleated giant cells, polygonal mononuclear cells, and histiocytes (may contain abundant hemosiderin or lipid). This same cell population is seen in PVNS in addition to hemosiderin. Desmoplastic fibroma is composed of dense and irregularly arranged collagen bundles with infrequent fibroblasts. Dermatofibroma is composed of nodular cellular proliferation consisting of short intersecting fascicles of fibroblastic cells in a loose crisscross or storiform pattern. Myositis ossificans is characterized by zonal proliferation with central fibroblasts and peripheral osteoblast-rimmed bone

 

trabeculae. Epithelial inclusion cysts are filled with keratin from desquamation of the hyperkeratotic, stratified squamous epithelial cells that line the cysts.

The Preferred Response to Question # 42 is 3.

 

Question 43 Figures 43a through 43d show the radiograph, bone scan, CT scan, and biopsy specimen of a 64-year-old woman who reports increasing right hip pain for the past 6 months. Treatment of this lesion consists of which of the following?

1. Surgery alone

2. Chemotherapy alone

3. Radiation therapy alone

4. Surgery and chemotherapy

5. Surgery and radiation therapy

 

DISCUSSION: The radiograph and the CT scan show an expansile, destructive lesion of the right acetabulum with stippled calcification. The bone scan shows increased uptake in the area of the lesion. The biopsy specimen reveals hypercellular cartilage, confirming the diagnosis of conventional chondrosarcoma. Treatment consists of surgery alone. In this patient, an internal hemipelvectomy with wide margins would be appropriate. Chondrosarcomas are resistant to both chemotherapy and radiation therapy. The Preferred Response to Question # 43 is 1.

 

Question 44 Figure 44a shows the lateral radiograph of a 28-year-old-man who has had shin pain for the past 2 years. Sagittal and axial MRI scans are shown in Figures 44b and 44c. A biopsy specimen is shown in Figure 44d. What is the best treatment for this lesion?

1. Observation

2. Curettage and grafting

3. External beam radiation alone 4- Wide resection alone

5- Chemotherapy and wide excision

 

DISCUSSION: The imaging showing a bubbly lesion in the anterior cortex of the tibia and the histology showing epithelial nests are consistent with adamantinoma. The best treatment for this lesion is wide resection without adjuvant treatments.

Histology demonstrating epithelial cells in a fibrous stroma confirm the diagnosis, and differentiate it from osteofibrous dysplasia, which follows the same anatomic distribution and has an overlapping radiologic appearance. Observation, curettage, and external beam radiation are not indicated for adamantinoma. There is no role for chemotherapy in this low-grade lesion. The Preferred Response # 44 is 4.

 

Question 45 An 18-year-old woman has had knee pain for the past 6 months. A radiograph and biopsy specimen are shown in Figures 45a and 45b. What is the most appropriate treatment option?

1- Wide resection and reconstruction 2- Radiofrequency ablation

3. Radiation therapy

4. Extended curettage with use of adjuvants 5- Observation

 

DISCUSSION: The radiograph and biopsy specimen are characteristic for giant cell

tumor of bone. The standard of care involves extended curettage, use of adjuvants to lower the risk of local recurrence, and filling of the void with bone graft and/or polymethylmethacrylate. Multiple adjuvants are acceptable and vary based on surgeon training and preference. These include phenol, liquid nitrogen, sterile water, and argon beam coagulation. Wide resection and skeletal reconstruction

 

should be reserved for extensive bone destruction where salvaging the involved bone is not feasible. Radiation therapy should be used with extreme caution because of the risk of secondary sarcomatous degeneration. In multiply recurrent lesions and more central, hard to access lesions, radiation therapy sometimes can play a role in the management of giant cell tumors. The Preferred Re# 45 is 4.

 

Question 46 A 50-year-old woman with a recent diagnosis of multiple myeloma is being evaluated for left hip pain and some difficulty with ambulation. She is still receiving her initial systemic management and has extensive skeletal involvement found on her initial skeletal survey and other staging modalities. Once referred for orthopaedic evaluation, an AP radiograph of her pelvis was obtained and is shown in Figure 46. What is the most appropriate surgical option for this patient?

1. Radical resection of the proximal third of the femur and tumor prosthetic reconstruction

2. Cemented hemiarthroplasty or total hip arthroplasty 3- Intramedullary nailing

4. Percutaneous screw fixation

5. Hip screw and side plate fixation

 

DISCUSSION: The goal of surgical management of myeloma is the same as it is for bone metastases - to relieve pain and restore function by achieving local tumor control and immediate mechanical stability. Pathologic femoral neck fractures that require surgical intervention should always be treated with removal and hemiarthroplasty or total hip arthroplasty. Bone cement augments structural stability and enables the patient to withstand the stress of immediate motion and function. Internal fixation options are less attractive because they typically do not allow immediate full weight bearing and would require the fracture to heal with the harmful effects of radiation and chemotherapy interfering with the healing process. Radical resection of the proximal femur and the tendinous attachments is not necessary for this patient and would increase the morbidity of the procedures. The Preferred Response to Question # 46 is 2.

Question 47 A 10-year-old boy reports increasing left knee pain. A radiograph, MRI scan, and biopsy specimen are shown in Figures 47a through 47c. What is the most likely diagnosis?

1. Osteoblastoma

2. Chondroblastoma 3- Giant cell tumor

4- Langerhans cell histiocytosis 5- Aneurysmal bone cyst

 

DISCUSSION: Chondroblastomas are painful benign tumors that typically occur in patients between the ages of 10 and 25. They almost always occur in an epiphysis or an apophysis. Although they are benign, the MRI scan frequently demonstrates surrounding edema as seen in this patient. The biopsy specimen shows multinucleated giant cells as well as chondroblasts. The chondroblasts are polygonal cells with well-defined cytoplasmic borders and indented nuclei. Osteoblastoma is a bone-forming lesion with interlacing osteoid and fibrovascular stroma similar to osteoid osteoma. Osteoblastoma and osteoid osteoma are differentiated more by size and clinical presentation than histology. Giant cell tumor is composed of multinucleated giant cells with stromal cells sharing similar nuclear morphology.

Langerhans cell histiocytosis is a common, usually self-limiting process with a variable radiographic appearance. The lesion is composed of plump histiocytes, eosinophils, and variable inflammatory cells. Aneurysmal bone cysts are not typical in the epiphysis and are composed of lakes of bloods surrounded by variable amounts of fibrous stroma containing giant cells, histiocytes, and hemosiderin. The Preferred Response to Question # 47 is 2.

 

Question 48 Figure 48 shows the AP and lateral radiographs of a 12-year-old boy with knee pain after a fall. Previous to the fall he denies any history of pain. What is the most likely diagnosis?

1- Unicameral bone cyst 2- Chondroblastoma

3. Fibrous dysplasia

4. Nonossifying fibroma

5. Osteosarcoma

 

DISCUSSION: The patient has a nonossifying fibroma. Nonossifying fibroma is classically an eccentric, lytic lesion with a thin sclerotic

 

border in the metaphysis. Unicameral bone cyst is typically central with variable surrounding sclerosis. Chondroblastoma is a lytic lesion in the epiphysis. Fibrous dysplasia is typically a central lytic lesion in the metaphysis or diaphysis with a ground glass appearance. Osteosarcoma is usually a mixed lytic/blastic lesion with bone destruction and formation, without sclerotic margins. Prefe Res# 48 is 4.

 

Question 49 The diagnosis of gout can be made either by the presence of tophaceous deposits in the skin or bursae of the extremities or by the presence of which of the following?

1. Elevated urine pH

2. Elevated serum uric acid

3. Calcium pyrophosphate crystals in the synovial fluid 4- Monosodium urate crystals in the synovial fluid

5- Elevated serum phosphate

 

DISCUSSION: Gout is an inflammatory arthritis caused by the presence of monosodium urate crystals in the joint. It is characterized acutely by a painful joint that remits after 1 to 2 weeks and recurs periodically. The diagnosis of gout can be made by confirming the presence of monosodium urate crystals in the joint fluid aspirated from the inflamed joint. Patients with gout may also have tophaceous deposits within the skin or bursae of the extremities. Elevated urine pH, serum uric acid, and serum phosphate can all be associated with numerous conditions and are not specific to gout. Calcium pyrophosphate crystals are associated with chondrocalcinosis (pseudogout). The Preferred Response to Question # 49 is 4.

 

Question 50 A 29-year-old man reports pain in the right little finger. The pain is worse at night. Symptoms were completely relieved with naproxen; however, the patient is no longer able to continue naproxen secondary to gastrointestinal problems. A radiograph is seen in Figure 50a and a CT scan is seen in Figure 50b.

What is the best treatment option for this patient? 1- Curettage

2. Observation

3. Acetaminophen

4. Wide resection

5. Radiofrequency ablation

 

DISCUSSION: The radiograph and the CT scan demonstrate a sclerotic lesion with a central nidus consistent with osteoid osteoma. The patient's pain characteristics (worse at night and relieved by anti-inflammatory drugs) are also typical of osteoid osteoma. The best treatment for this patient would be curettage with a power burr which is associated with less than 10% local recurrence. Observation is not a good option for this patient because he is experiencing pain. Studies have demonstrated high levels of cyclooxygenases and prostaglandins in the tumor osteoblasts. This might explain why many patients receive dramatic relief with anti-inflammatory medications. Acetaminophen would not be expected to provide adequate pain relief. Whereas radiofrequency ablation is currently the most common method employed to treat osteoid osteomas, this procedure is contraindicated for lesions in the digits because of the risk of thermal necrosis of the overlying skin as well as the digital neurovascular structures. Wide resection would be overly aggressive for this benign lesion. The Preferred Response to Question # 50 is 1.

 

Question 51A 57-year-old man was treated for an upper extremity high-grade soft- issue sarcoma 9 months ago with resection and postoperative radiation therapy.

At his restaging visit, a new solitary lesion is seen on the CT chest scan shown in Figure 51. What is the most effective treatment of this new identified lesion?

1. Wedge resection

2. Pneumonectomy

3. Chemotherapy

4. Radiation therapy

5. Palliative care

 

DISCUSSION: For patients with soft-tissue sarcoma, the lungs are the most common site of metastatic disease. Although pulmonary metastases most commonly arise from primary tumors in the extremities, they may arise from almost any primary site or histology. Resection of metastatic disease is the single most important factor that determines outcome in these patients. Long-term survival is possible in selected patients, particularly when recurrent pulmonary disease is resected. Surgical excision of lung metastases from soft-tissue sarcomas is well accepted and should be considered as a first line of treatment if preoperative evaluation indicates that complete resection of the metastases is possible. With an isolated lesion, a wedge resection or lobectomy would be adequate for controlling disease. Pneumonectomy could be used for more extensive disease. Further investigation is needed before

 

chemotherapy can be recommended as additional therapy. Radiation therapy is not typically used for pulmonary metastasis from soft-tissue sarcomas. Pre Re# 51 is 1.

 

Question 52 Figures 52a and 52b show the radiographs of a 30-year-old-man who had Ewing's sarcoma at the age of 10 treated with radiation therapy for local control. What is the most likely diagnosis?

1- Recurrent Ewing's sarcoma 2- Osteomyelitis

3. Radiation-induced sarcoma

4. Metastatic adenocarcinoma

5. Bone infarct

 

DISCUSSION: The most likely diagnosis is radiation-induced sarcoma, which typically occur years after the radiation is received. The

radiographs show a lytic lesion in the area of previously treated Ewing's sarcoma. Occasionally Ewing's sarcoma is treated with radiation therapy, typically in locations where limb salvage is not feasible. Recurrent Ewing's sarcoma would be unusual 20 years after the primary tumor, bone infarct is not purely radiolucent, adenocarcinoma is rare in patients younger than age 40, and osteomyelitis would be an unusual diagnosis in this clinical setting. The Preferred Response # 52 is 3.

 

Question 53 Based on the radiograph, post-gadolinium enhanced MRI scan, and histologic study shown in Figures 53a through 53c, what is the most likely diagnosis?

 

1- Undifferentiated pleomorphic sarcoma 2- Synovial sarcoma

3. Liposarcoma

4. Fibromatosis

5. Epithelioid sarcoma

 

DISCUSSION: Fibromatosis more frequently occurs in women, with a peak incidence between puberty and age 40 years. On MRI, the tumor is isointense to hypointense with skeletal muscle on both pulse sequences but varies depending on the amount of collagenous stroma; it enhances markedly with gadolinium administration as seen in Figure 53b. Histologically, this tumor is composed of fibroblasts and myofibroblasts in a collagenous matrix with low mitotic activity. Although the tumor recurs frequently (due to its infiltrative growth pattern) despite wide local surgery, it does not metastasize. Chemotherapy using low-dose methotrexate and vinblastine has been reported to be beneficial in treating this tumor. Radiographically, with a few exceptions, it is very difficult to distinguish one soft-tissue tumor from another. Histologically, undifferentiated pleomorphic sarcoma contains spindle malignant cells that have a storiform pattern. Synovial sarcomas contain spindle cells arranged in short intersecting fascicles; they may also have pseudoglandular areas in the biphasic form of disease. Epithelioid sarcoma contains spindled and epithelioid cells arranged in nodules with necrosis and hemorrhage (pseudoangiosarcomatous appearance). The Preferred Response to Question # 53 is 4.

 

Question 54The radiographs, bone scan, and MRI scans of a 10-year-old girl are seen in Figures 54a through 54f. A biopsy specimen is seen in Figure 54g. Which of the following represents the treatment option with the best prognosis?

 

1. Wide resection without adjuvant

2. Methotrexate-based chemotherapy with radiation therapy 3- Methotrexate-based chemotherapy with wide resection

4. Vincristine, doxorubicin, cyclophosphamide, and dactinomycin-based chemotherapy with wide resection, with or without radiation therapy

5. Vincristine, doxorubicin, cyclophosphamide, and dactinomycin-based chemotherapy

 

 

DISCUSSION: The patient has Ewing's sarcoma. This tumor is best treated with neoadjuvant chemotherapy consisting of a regimen based around vincristine, doxorubicin, cyclophosphamide, and dactinomycin in combination with wide resection or amputation. Radiation therapy may have a role for local disease control with close surgical margins, surgically inaccessible sites, or in the presence of advanced disease. Osteosarcoma is treated with methotrexate-based chemotherapy and wide resection or amputation. The Preferred Response to Question # 54 is 4.

 

Question 55 A 32-year-old woman has had hip pain for 8 months. Initially, the pain was present with activity but has now progressed to pain also at rest. An AP radiograph of the pelvis, CT scan, and MRI scan are seen in Figures 55a through 55c. Figures 55d and 55e show the biopsy specimens. What is the most appropriate treatment?

 

1. Observation

2. Curetting and bone grafting

3. Chemotherapy followed by wide excision 4- Radiotherapy

5- Radical resection

 

DISCUSSION: Chondromyxoid fibroma is a rare tumor and is most often found in the proximal tibia. Other common sites include the collective bones of the foot and ankle as well as the pelvis. The radiograph demonstrates a radiolucent abnormality in the right ilium that is partially obscured by bowel gas. The CT scan reveals a destructive, low attenuation abnormality with a rim of bone on the periphery and subtle internal matrix. The coronal T2-weighted MRI scan shows a hyperintense signal abnormality with a lobular growth pattern; the transition between the lesion and normal bone is distinct. Low power H&E stained tissue shows a biphasic histologic pattern with hypercellular spindle cells surrounding a relatively hypocellular area. High power reveals very characteristic stellate cells. Treatment for this condition is intralesional (curetting and bone grafting). Local recurrence is reported in 20% to 25% of cases. Chondrosarcoma is in the differential in this case and would require wide local excision. Chondroblastoma is benign, albeit sometimes aggressive and does not respond to adjuvant therapies such as chemotherapy or radiation therapy. The Preferred Response to Question # 55 is 2.

 

Question 56 A 72-year-old woman is evaluated for sacrococcygeal pain sustained after a twisting injury. Radiographic and MRI evaluation confirms the presence of a nondisplaced fracture at the sacrococcygeal junction. Over a 3-week period, the pain has gotten significantly better. No additional lesions or injuries are noted.

Laboratory studies show a serum calcium level of 8.8 mg/dL (normal 8.6-10.3 mg/dL) and a 25-OH Vitamin D level of 14 ng/mL (normal 30-80 ng/mL). What is the most appropriate treatment for this patient?

1. Expectant observation

2. Calcium supplementation

3. High dose vitamin D supplementation 4- Bisphosphonate therapy

5- Surgical fixation of the sacrococcygeal fracture

 

DISCUSSION: Chronic Vitamin D deficiency leads to problems with bone health and has been shown to increase the risk of falls in the elderly. Appropriate supplementation of Vitamin D has been shown to decrease this risk. Conversion in

 

the skin decreases with age and may be nearly nonexistent in darkly pigmented individuals. Vitamin D3 is the preferred form for supplementation, but D2 is the form most available by prescription in the US. Hypervitaminosis D is rare and very high doses can be tolerated without significant concern for toxicity. Because the patient has sustained one insufficiency fracture, she is at risk for insufficiency fractures in other skeletal locations, rendering expectant observation insufficient. Her serum calcium is normal, and with a low Vitamin D level, calcium utilization in her system would be inadequate. Bisphosphonate therapy in addition to calcium and vitamin D supplementation may provide a good long-term solution, but should not be instituted until the bone mineral imbalance has been adequately corrected. Surgical fixation of this fracture is not indicated, particularly in lieu of improving symptoms.

The Preferred Response to Question # 56 is 3.

 

Question 57 Figures 57a through 57c show the radiograph, MRI scan, and photomicrograph of a 13-year-old boy who reports increasing left groin pain. What is the most appropriate method of treatment of this lesion?

 

1. Surgery alone

2. Radiation therapy alone 3- Chemotherapy alone

4. Chemotherapy and surgery

5. Surgery and radiation therapy

 

DISCUSSION: The radiograph demonstrates an expansile lesion of the left superior pubic ramus. The MRI scan demonstrates multiple fluid-fluid levels consistent with an aneurysmal bone cyst. The photomicrograph demonstrates cavernous hemorrhagic tissue with a benign-appearing spindle cell stroma and giant cells, thus confirming the diagnosis of aneurysmal bone cyst. Surgical management is the recommended treatment for this lesion. Most aneurysmal bone cysts are amenable to curettage and bone grafting. Lesions in expendable bones can be treated with resection. Embolization may decrease intraoperative blood loss when treating large lesions of the pelvis. Radiation therapy has been reported to be effective but is seldom used secondary to the risk of malignant transformation as well as the risk of damage to reproductive organs, physes, and the spinal cord. Chemotherapy has no role in the treatment of this lesion.

The Preferred Response to Question # 57 is 1.

 

Question 58 Figures 58a and 58b show the radiographs of an otherwise healthy 64- year-old man who has had right groin pain for the past 3 months. What is the next most appropriate step in management?

1. Biopsy

2. Observation

3. Radiation therapy

4. Prophylactic fixation of the femur 5- Bone scan, CT scan of the

chest/abdomen/pelvis, laboratory studies

 

DISCUSSION: The radiographs show a

radiolucent lesion in the proximal femur. In a patient older than age 40 years, a new painful bone lesion most likely represents metastatic carcinoma or multiple myeloma even if the patient does not have a known history of cancer. The diagnosis must be firmly established and the patient should be staged prior to initiating treatment. Imaging studies should be completed prior to proceeding with a biopsy. This patient should undergo a bone scan to look for other lesions. A CT scan of the chest, abdomen, and pelvis should be performed to look for a primary tumor as well as other sites of metastases. (Lung or kidney would be the most common primary sites for a patient who presents with metastases of unknown origin.) Serum and urine protein electrophoresis should be obtained to look for multiple myeloma. The Preferred Response # 58 is 5.

 

Question 59 A 23-year-old woman who noted 1 day of thigh pain after jogging now reports persistent thigh swelling and can feel a mass. The radiograph, CT scan, and MRI scans are shown in Figures 59a through 59d. What is the most likely diagnosis?

 

1. Soft-tissue sarcoma

2. Pseudoaneurysm

3. Abscess

4. Osteosarcoma

5. Myositis ossificans

 

DISCUSSION: Myositis ossificans (MO) is a reparative lesion that is distinguished by the presence of metaplastic bone formation. The important entity that MO must be distinguished from is extraskeletal osteosarcoma. Extraskeletal osteosarcoma usually occurs in older patients and lacks the zonation phenomenon of MO. Myositis ossificans develops a well-defined ossified rim, maturing peripherally more than centrally, where osteosarcomas do the opposite. Histologically the two may be confusing; therefore, clinical and radiographic evaluation is a critical factor in the diagnosis. Soft-tissue sarcoma, pseudoaneurysm, and abcess do not have zonal ossification patterns. The Preferred Response to Question # 59 is 5.

 

Question 60 A 33-year-old man has a painless mass in the anterior thigh. Selected sequences of MRI scans are shown in Figure 60a (T1) and Figure 60b (T2 fat saturated). Biopsy photomicrographs are shown in Figure 60c (low-power) and 60d (high-power). Cytogenetics of the specimen shows a 12:16 translocation. What is the most likely diagnosis?

1. Well-differentiated liposarcoma

2. Myxoid liposarcoma

3. Round cell liposarcoma

4. Fibrolipomatous hamartoma

5. Intramuscular lipoma

 

DISCUSSION: The T1-weighted MRI scan shows a heterogeneous fatty tumor within the thigh musculature. The amount of heterogeneity and enhancement are more suggestive of malignancy, but are not diagnostic. The histology shows lipoblasts and primitive mesenchymal cells within a stroma myxomatous tissue with a delicate plexiform capillary network. The cytogenetics demonstrates the characteristic translocation for a myxoid liposarcoma. Treatment is usually consists of wide local excision with or without radiation therapy. Chemotherapy may be considered if there is a significant (25% or greater) round cell component.Preferred Resp# 60 is 2.

 

Question 61 A 59-year-old man who works as a laborer has had left hip pain for the past 12 months. He reports some worsening with activity and occasional pain that wakes him from sleep. He rates his baseline pain as 3 out of 10. He denies any fevers, malaise, or other systemic symptoms. A radiograph, CT scan, and biopsy photomicrographs are shown in Figures 61a through 61e. Appropriate treatment of this lesion would entail which of the following?

1- Chemotherapy and wide resection 2- Radiation therapy alone

3- Extended curettage and radiation therapy 4- Wide surgical resection alone

5- Observation with repeat scans in 3 months

 

DISCUSSION: This is a classic presentation of chondrosarcoma of the pelvis. Wide surgical resection is the treatment of choice. Though chemotherapy may be offered for patients with dedifferentiated chondrosarcoma, the histology of this lesion is consistent with an intermediate to high-grade myxoid chondrosarcoma.

Chondrosarcomas are radioresistant, and should be aggressively treated with surgery. Extended intralesional resection of low-grade chondrosarcoma is acceptable in the appendicular skeleton; it is inappropriate in patients with intermediate or high-grade lesions and lesions that occur in the pelvis and other axial sites. The Preferred Response to Question # 61 is 4.

 

Question 62 Figures 62a through 62c show the radiographs of a 40-year-old man who works as a heavy laborer and has hand pain after sustaining a minor injury. What is the most appropriate treatment for this patient?

1. Biopsy

2. Ray resection

3. Protective splinting followed by observation after fracture healing

4. Protective splinting followed by curettage and bone grafting after fracture healing

5. Acute open reduction and internal fixation combined with curettage and bone grafting

 

DISCUSSION: The radiographs are consistent with an enchondroma with pathologic fracture. Allowing the fracture to heal and then proceeding with curettage and bone grafting allows a more limited procedure with satisfactory results compared with acute surgical treatment. Hand enchondromas that have fractured should generally be treated surgically because repeated fractures will typically occur, particularly in a person who works as a laborer. MRI will not add to the diagnostic work-up and the presence of a fracture may confuse the interpretation. Biopsy is not necessary unless aggressive bony changes are seen. Ray resection is generally reserved for bone and soft-tissue sarcomas or other primary malignancies involving the digit. The Preferred Response to Question # 62 is 4.

 

Question 63 A 47-year-old woman with a history of breast cancer and a recent diagnosis of lung carcinoma with multiple painful biopsy-proven skeletal metastasis now reports progressive weight-bearing pain in her left thigh. Current treatment consists of chemotherapy for the lung mass and radiation therapy. An AP radiograph of the left femur is shown in Figure 63. What is the best option for treatment of her thigh pain?

1. Bisphosphonate therapy

2. Resection and megaprosthetic reconstruction 3- Prophylactic rodding

4. Radiation therapy

5. Chemotherapy

 

DISCUSSION: Predicting which patients will sustain a fracture with metastatic bone disease is a difficult clinical decision. Mirel's rating system is a useful clinical tool but must be used cautiously. Lower extremity peritrochanteric, large, radiolucent, and painful lesions

 

are at highest risk for fracture. The ultimate goal is palliative in nature and designed to limit pain, minimize time in the hospital, and improve the quality of life in these patients with limited survival time. If a high risk lesion is treated with radiation therapy first, the bone will become weaker before starting to regain structural integrity and the fracture risk increases. Timing of prophylactic fixation, radiation therapy, and chemotherapy requires a multidisciplinary team of doctors working collaboratively. Bisphosphonates should be included in the medical treatment for most patients with metastatic bone disease to lower the risk of further skeletal complications. They are not indicated for acute treatment of impending fractures.

Resection of a metastatic lesion is reserved for patients in which internal fixation devices will not have adequate bone stock present to allow stabilization and immediate weight bearing or in patients with selected isolated metastases, such as those caused by renal carcinoma. Radiation therapy and chemotherapy have already failed to control progressive bone destruction and pain in this patient.

 

The Preferred Response to Question # 63 is 3.

 

Question 64 A 45-year-old man has an enlarging, painless soft-tissue mass in his arm. An MRI scan shows a 15 x 8 x 6 cm enhancing, heterogenous deep mass.

Biopsy shows a sarcoma. What is the next most appropriate imaging study to obtain?

 

1. PET scan

2. Bone scan

3. Chest CT

4. Abdomen CT

5. MRI of the chest

 

DISCUSSION: Staging takes into consideration the histologic grade, size, depth, and presence of metastasis of a tumor. Locoregional lymph node spread is uncommon for most sarcomas and is evaluated by palpation; suspicious areas require further imaging to assess. The chest is the most common area for soft-tissue sarcomas to metastasize and should be considered for imaging prior to biopsy to assist with the staging of the patient. In some specific subtypes (myxoid liposarcoma), bone scans and abdominal imaging are important to obtain to exclude metastases. The role for PET scans in patients with soft-tissue sarcomas is still being defined.

 

The Preferred Response to Question # 64 is 3.

 

Question 65 A 20-year-old collegiate field hockey player has had diminished knee flexion for the past 3 years. Lately she has noted right knee pain that requires her to stop playing. Radiographs are shown in Figures 65a and 65b. What is the next best step in management?

 

1. Radiation therapy

2. Surgical biopsy

3. Chemotherapy

4. Knee arthroscopy

5. Bisphosphonates

 

DISCUSSION: The lesion has the characteristic features of a parosteal osteosarcoma, including its surface location on the posterior distal femur, decreased range of motion, and pain. Biopsy is necessary to confirm a diagnosis before recommending treatment. Chemotherapy and radical resection may be indicated in dedifferentiated disease, but should be considered only after a biopsy and appropriate staging have been completed. There is no role for knee arthroscopy or bisphosphonates.

The Preferred Response to Question # 65 is 2.

 

66.Which of the following genes is involved in the etiology of aneurysmal bone cyst?

1- ASPL 2- ATF1 3- EWS 4- PAX3 5- USP6

 

DISCUSSION: Aneurysmal bone cyst was recently shown definitively to be a neoplasm driven by upregulation of the ubiquitin-specific protease USP6 (Tre2) gene on 17p13 when combined by translocation with a promoter pairing. The most commonly described translocation is t(16;17)(q22;p13) which results in juxtaposition of the promoter region CDH11 on 16q22. In the past, all aneurysmal bone cysts were thought to be reactive in nature. Whereas primary aneurysmal bone cysts are now known to be neoplasms, secondary aneurysmal bone cysts are not because no translocation has been identified in them. ASPL is involved in alveolar soft part sarcoma (tX;17)(TFE3-ASPL). ATF1 is involved in clear cell chondrosarcoma. EWS is a gene on chromosome 22 involved in several relevant musculoskeletal oncology conditions, including Ewing's sarcoma (t11;22)(EWS-FLI1), desmoplastic small round cell tumor (t11;22)(EWS-WT1), extraskeletal myxoid chondrosarcoma (t9;22)(EWS- CHN), and clear cell chondrosarcoma (t12;22)(EWS-ATF1). PAX3 is involved in alveolar rhabdomyosarcoma (t2;13)(PAX3-FKHR). The Preferred Respo# 66 is 5.

 

Question 67 A 39-year-old man has multiple bone lesions in his right leg, bowing deformity, and limb-length inequality. Radiographs are shown in Figures 67a through 67c. A biopsy specimen is shown in Figure 67d. When counseling the patient regarding his diagnosis, how would you explain the inheritance pattern for his disease?

1. Autosomal dominant

2. Autosomal dominant with variable penetrance 3- Autosomal recessive

4. Sex-linked recessive

5. No known inheritance pattern

 

DISCUSSION: The patient's radiographs show multiple lytic bone lesions with some femoral deformity. The radiographic differential would include fibrous dysplasia, enchondromatosis (Ollier's disease), eosinophilic granulomatosis, metastatic disease, multiple myeloma, hyperparathyroidism (brown tumors), and infection. The pathology demonstrates relatively acellular cartilaginous tissue, supporting the diagnosis of Ollier's disease. Commonly, patients with enchondromatosis have problems with shortened and/or bowing of their affected limbs. Additionally, unlike solitary enchondromas which have a very low risk of malignant transformation (< 1%), patients with enchondromatosis have a significantly higher risk of malignant transformation, up to 25%. Despite the disease and lesions being present from birth, there is no described inheritance pattern associated with the disease.Pre Re# 67 is 5.

 

Question 68 A 10-year-old boy has a 5-month history of pain in the left thigh and knee that has increased in severity such that he is currently unable to walk secondary to pain. He has a large fusiform swelling about the distal femur. A radiograph of both knees is shown in Figure 68a, and MRI scans are shown in Figures 68b through 68d. After complete staging, a biopsy is performed and a specimen is shown in Figure 68e. What is the most likely diagnosis?

 

1. Osteomyelitis

2. Stress fracture

3. Osteoblastoma

4. Osteosarcoma

5. Ewing's sarcoma

DISCUSSION: The patient's clinical presentation is one of progressive pain. His radiographs show a destructive, bone-producing lesion that has extended outside the bone into the soft tissues. The pathology shows the production of osteoid by malignant spindle stromal cells. This is consistent with osteosarcoma. There is no inflammatory component of the histology to suggest osteomyelitis. Whereas osteoblastoma can be confused with osteosarcoma, the histology of malignant stromal cells as well as the radiographic findings are classic for osteosarcoma.

Ewing's sarcoma can be associated with a significant soft-tissue mass, as seen in the MRI scan; however, histology would demonstrate a small blue round-cell tumor. The Preferred Response to Question # 68 is 4.

 

Question 69 A 65-year-old woman has a bone mineral density t-score of -2.0. She has no identifiable secondary cause of bone loss. In addition to calcium and vitamin D supplementation, this patient should be considered for

1. calcitonin.

2. hormone replacement therapy. 3- teriparatide.

4. bisphosphonate therapy.

5. observation.

 

DISCUSSION: A patient with a bone mineral density t-score of between -1.0 and -2.5 should be considered for osteoporosis prevention therapy. This would consist of calcium (1,200 to 1,500 mg daily), vitamin D (800 to 1000 IU daily), and a bisphosphonate. Calcitonin and teriparatide are used to treat established osteoporosis (t-score of -2.5 or lower). Observation is not recommended with a t-

 

score of less than -1.0. Hormone replacement therapy is associated with an increased risk of cardiovascular disease and breast cancer. Pref Re # 69 is 4.

 

Question 70 Figures 70a and 70b show the radiograph and MRI scan of a 66-year- old man who has fatigue, weight loss, and muscle weakness. Examination reveals marked pain and discomfort in the left mid leg. Biopsy specimens are shown in Figures 70c and 70d. What is the most likely diagnosis?

1. Mastocytosis

2. Multiple myeloma

3. Hyperparathyroidism

4. Metastatic carcinoma

5. Multicentric giant cell tumor

 

DISCUSSION: The signs and symptoms of hyperparathyroidism are similar to those in patients with diffuse skeletal metastases. Serum markers are very helpful in making the diagnosis. In this patient, the radiograph shows multiple lesions in the tibia and proximal fibula that have a variable appearance. For example the mid-tibial lesion is radiolucent and slightly expansile whereas the more proximal tibial lesions are radiodense. The proximal fibula lesion is mixed (radiolucent/radiodense). These findings would be very uncommon in patients with myeloma, metastatic disease, or multicentric giant cell tumor. The histopathology shows a bland fibrous stroma with multiple multinucleated giant cells. On higher power, the stromal cells are spindled and the giant cells are relatively small in contrast to giant cell tumor where the giant cells are larger and the stromal cells are more rounded with nuclei that closely resemble those in the giant cells. There is blood extravasation (stromal hemorrhage) and hemosiderin deposition. The constellation of findings is most consistent with brown tumors due to hyperparathyroidism (secondary to a parathyroid adenoma in this patient). The Preferred Response to Question # 70 is 3.

 

Question 71 A 76-year-old woman has a painful, snapping mass at the inferior angle of the scapula. She has no history of trauma to the area. MRI scans are shown in Figures 71a through 71c. A biopsy specimen is shown in Figure 71d. What is the most appropriate treatment at this time?

1. Observation

2. Excision

3. Radiation therapy alone

4. Chemotherapy followed by wide excision 5- Local steroid injection

 

DISCUSSION: Elastofibroma is a benign, likely inflammatory mass that typically occurs deep to the inferior angle of the scapula. It may be bilateral and may be symptomatic with either pain or mechanical symptoms related to its location. The recommended treatment for symptomatic lesions is excision. Small or asymptomatic lesions may also be observed. Biopsy to confirm the diagnosis and to exclude sarcoma seems prudent. Neither radiation therapy or chemotherapy are indicated for this benign tumor. Local steroid injection plays no role in the treatment of benign elastofibroma. The Preferred Response to Question # 71 is 2.

 

Question 72 Figures 72a and 72b show the radiograph and biopsy specimen of a 92-year-old woman who reports increasing right shoulder pain. What is the most likely diagnosis?

 

1. Enchondroma

2. Juxtacortical chondroma

3. Conventional chondrosarcoma

4. Dedifferentiated chondrosarcoma

5. Mesenchymal chondrosarcoma

 

DISCUSSION: The radiograph shows a lesion of the proximal humerus with stippled calcification suggestive of a cartilaginous neoplasm. The lesion has eroded through the cortex, and therefore, most likely represents a chondrosarcoma. The biopsy specimen reveals a high-grade spindle cell sarcoma adjacent to low-grade cartilage and is thus diagnostic of dedifferentiated chondrosarcoma. An enchondroma is a benign cartilaginous tumor contained entirely within the medullary cavity. A juxtacortical chondroma is a benign cartilage tumor on the surface of a bone.

Conventional chondrosarcoma could present a radiographic appearance similar to this case; however, it would not contain a spindle cell component. Mesenchymal chondrosarcoma typically has small round blue cells and vascular proliferation with a hemangiopericytomatous pattern.

The Preferred Response to Question # 72 is 4.

 

Question 73 An otherwise healthy 30-year-old woman with no history of malignancy reports a 1-year history of right hip and low back pain. A radiograph, CT scan, and MRI scan are shown in Figures 73a through 73c. A biopsy specimen is shown in Figure 73d. What is the most likely diagnosis?

 

1- Aneurysmal bone cyst 2- Hemangioma of bone 3- Sarcoid

4- Paget's disease of bone 5- Chondrosarcoma

 

DISCUSSION: The patient has a lytic lesion in her right ilium with coarsened trabeculae. The radiographic differential for such a lesion would include aneurysmal bone cyst, hemangioma of bone, sarcoid, Paget's disease of bone, and fibrous dysplasia. The photomicrograph of the biopsy demonstrates small vascular channels lined with a single layer of endothelial cells, supporting the diagnosis of hemangioma of bone. There are no giant cells typically seen in an aneurysmal bone cyst and the early phases of Paget's disease. There are no granulomas to suggest sarcoid, and the histopathologic features are not consisent with cartilage. Most patients with hemangiomas require no treatment. Lesions causing symptoms are best treated with intralesional excision.

 

The Preferred Response # 73 is 2.

Question 74 A 56-year-old woman has a 5-month history of a rapidly growing mass in the posteromedial aspect of the right leg. A clinical photograph, MRI scan, and biopsy specimen are shown in Figures 74a through 74c. What is the most appropriate treatment for this patient?

1. Observation

2. Wide resection alone

3. Radiation therapy alone

4. Wide resection and radiation therapy 5- Debridement and antibiotics

 

DISCUSSION: The clinical photograph shows an aggressive tumor growing through the skin (fungating). The axial T1-weighted MRI scan with contrast shows a large mass in the posterior and proximal leg with heterogeneous enhancement and a large nonenhancing center that suggests tumor necrosis, two poor prognostic factors in disease outcome. Finally, the histopathology suggests an undifferentiated pleomorphic spindle cell neoplasm. This is a high-grade sarcoma that requires both radiation therapy and wide excision to local disease control. The histopathology is characteristic of a high-grade sarcoma, not a local infection. The role of chemotherapy for most adult soft-tissue sarcomas remains controversial. The Preferred Response to Question # 74 is 4.

 

Question 75 An otherwise healthy 12-year-old boy has ankle pain after being kicked while playing soccer. Radiographs are shown in Figures 75a and 75b. Examination reveals tenderness to palpation, but not with weight bearing. He had no pain preceding the incident. What is the next most appropriate step in management?

1. Observation

2. Curettage and grafting 3- Wide surgical resection 4- Whole body bone scan 5- Chemotherapy

 

DISCUSSION: The lesion shown is a nonossifying fibroma. With no pain preceding the traumatic episode and painless weight bearing, the lesion does not appear at risk for fracture. Simple observation with repeat radiographs at a time interval (3 to 6 months) to document stability is sufficient. Surgical intervention is unnecessary because the risk of fracture is low and the natural history is one of spontaneous regression during adolescence. The lesion is benign; therefore, chemotherapy is not indicated. While a bone scan may provide some useful information, it is unnecessary for the diagnosis and adds little to management decisions. Pre Resp # 75 is 1.

 

Question 76 A 31-year-old patient has had a left medial elbow mass for 1 month. The mass has been increasing in size and has now become very painful and erythematous. MRI scans are shown in Figures 76a and 76b. Laboratory studies show an erythrocyte sedimentation rate of 49 mm/h (normal 0 to 20 mm/h) and C-reactive protein level of 23 mg/L (normal 0 to 0.3 mg/L). Histology showed lymphoid tissue and multiple necrotizing granulomas. What organism is responsible for this clinical picture?

1. Borrelia burgdorferi

2. Trichophyton tonsurans

3. Bartonella henselae

4. Mycobacterium avium

5. Corynebacterium minutissimum

 

DISCUSSION: Cat scratch disease (CSD) is an important diagnosis for

the orthopaedic surgeon to consider in the differential diagnosis of soft-tissue masses adjacent to epitrochlear or cervical lymph nodes. It is a soft-tissue tumor simulator and a high index of suspicion is necessary in all patients with upper extremity or head and neck adenopathy and a history of cat exposure. Although generally not required for diagnosis, cross-sectional imaging will reveal a mass with surrounding edema in an area of lymphatic drainage. A peripheral blood sample can be tested for Bartonella henselae - the offending organism with this diagnosis.

Classically the histology of these lesions when biopsied will show multiple necrotizing granulomas. Mycobacterium avium is the only other organism that would demonstrate a granulomatous reaction and the location is classic for CSD. Borrelia burgdorferi is associated with Lyme disease. Mycobacterium avium may be a source of immunocompromised infections in HIV patients. Trichophyton tonsurans and corynebacterium minutissimum are not associated with orthopaedic diseases.

The Preferred Response to Question # 76 is 3.

 

Question 77 A 45-year-old woman has a painful mass in the dorsum of the right wrist. It is firm and nontender to palpation. She states it has slowly gotten bigger over the past 3 years. You suspect a dorsal wrist ganglion. What is the most definitive way to confirm this diagnosis?

1- Observe it for 1 year to see if it changes dramatically in size. 2- Obtain a gadolinium enhanced MRI scan.

3. Obtain radiographs, looking for scapholunate joint degenerative changes.

4. Perform a needle aspiration and send the aspirate for cytologic examination. 5- Apply direct firm manual pressure over the mass to see if it can be ruptured.

 

DISCUSSION: Dorsal wrist ganglions are synovial cysts that arise most frequently from the scapholunate joint. They often extend between the extensor digitorum communis and extensor pollicis longus tendons at the wrist. Aspiration of the cyst is both oncologically safe if done appropriately and also the easiest way to definitively confirm the diagnosis. Clear, yellow viscous fluid/gel is most often aspirated.

Cytologic evaluation is mandatory to exclude myxoid neoplasms. Because the lesion has been present for 3 years, further observation is not warranted. The classic presentation, physical examination findings, and location make MRI and radiographs unnecessary. Manual rupture of the mass is not recommended. Pref Res # 77 is 4.

 

Question 78 A 68-year-old woman has had progressive pain in the right thigh for the past several months. She has a history of hypertension, treated with hydrochlorothiazide and osteoporosis treated with alendronate for 10 years. At this point, she is virtually wheelchair bound. Radiographs are shown in Figures 78a and 78b. Additional studies show no signs of systemic disease. What is the most likely etiology of her condition?

 

1- Prolonged use of bisphosphonates 2- Use of calcium-wasting diuretics

3. Occult metastatic cancer

4. Vitamin D-resistant rickets 5- Disuse osteopenia

 

DISCUSSION: The patient has been on alendronate for 10 years and has evidence of a proximal diaphyseal fatigue fracture. These have been associated with long-term use of

 

bisphosphonates. Staging studies have failed to show systemic disease, and while metastasis with an unidentifiable primary does occur, it would be unlikely to present with this radiographic appearance, now recognized to be classic for stress fractures associated with chronic bisphosphonate usage. Hydrochlorothiazide does not cause calcium wasting. Vitamin D-resistant rickets would be a long-standing event and would present much earlier in life, often with pronounced deformities. Whereas the patient's progression to intolerance of weight bearing likely has led to some degree of disuse osteopenia, the underlying problem is the long-term bisphosphonate exposure. The Preferred Response to Question # 78 is 1.

 

Question 79 A 32-year-old man reports pain, and examination reveals swelling and tenderness about the knee and distal femur. A radiograph and an MRI scan are shown in Figures 79a and 79b. A bone scan is shown in Figure 79c, and a biopsy specimen is shown in Figure 79d. Cytogenetic analysis of the biopsy specimen failed to show an 11:22 chromosomal translocation. What is the most likely diagnosis?

1. Ewing's sarcoma

2. Bacterial osteomyelitis

3. Tuberculous osteomyelitis 4- Lymphoma of bone

5- Osteosarcoma

 

DISCUSSION: The biopsy specimen reveals sheets of blue cells and therefore falls within the differential of blue cell tumors. The majority of Ewing's sarcomas will have the 11:22 translocation present. The pathology does not reveal the mixed cell inflammatory process seen in osteomyelitis nor does it show the caseating granulomas of tuberculosis. There are no findings of any osteoid being produced by malignant-appearing spindle cells typical of osteosarcoma. Malignant lymphomas of bone must be considered within the differential for sclerotic lesions of bone with soft-tissue masses as in this patient. The Preferred Response to Question # 79 is 4.

 

Question 80 An 18-year-old woman has pain and swelling in her lateral hindfoot. On examination, she has significant pain with resisted eversion of the foot. MRI scans are seen in Figures 80a (T1) and Figure 80b (non-fat T2), and a biopsy specimen is seen in Figure 80c. What is the most appropriate treatment for this patient?

 

1. Marginal excision

2. Transtibial amputation

3. Injection of a radioisotope

4. Chemotherapy and radiation therapy

5. Wide local excision and radiation therapy

 

DISCUSSION: The lesion has a stalk that originates in the subtalar joint, fills the sinus tarsi, and effaces the peroneal tendons. Soft-tissue masses that are periarticular should arouse suspicion for synovial sarcoma. Unlike synovial sarcoma however, this lesion was hypointense on both T1 and T2 MRI pulse-weighted sequences because of the large amounts of hemosiderin deposition, characteristic of pigmented villonodular synovitis. Furthermore, intra-articular synovial sarcomas are very rare. Radioisotopes are not very effective for pigmented villonodular synovitis in the foot and ankle because contiguous involvement of multiple joints is not uncommon.

Furthermore, skin necrosis can occur with extravasation of radioisotope into the soft tissue. For this reason, complete (marginal) excision is recommended. For recurrent tumors, combined surgery and external beam irradiation has been advocated by some investigators. This is a benign tumor; therefore, aggressive surgical procedures (amputation and wide excision) are not appropriate. Radiation therapy may be a consideration in patients with recurrent and destructive disease.

The Preferred Response to Question # 80 is 1.

 

Question 81 A 26-year-old man has a 1-year history of worsening heel pain. There is no history of penetrating injuries to the heel. A radiograph, bone scan, and MRI scan are shown in Figures 81a through 81c, and biopsy specimens are shown in Figures 81d and 81e. Management should consist of which of the following?

1- Curettage with or without local adjuvants and bone grafting 2- Injection of corticosteroids

3- Irrigation, debridement, and antibiotic treatment 4- Wide resection

5- Chemotherapy and wide resection

 

DISCUSSION: With an epiphyseal bone lesion, the radiographic differential would consist of chondroblastoma, Brodie's abscess, or giant cell tumor of bone. Because of the location in the calcaneus, consideration should also be given for an epidermal inclusion cyst if there is a history of penetrating trauma. The biopsy specimens show a very cellular and vascular lesion with mononuclear chondroblasts with grooved nuclei ("coffee-bean nuclei"). There are some osteoblast-like giant cells. The surrounding chondroid matrix stains pink and has scant areas of fine mineralization outlining the stromal cells ("chicken-wire"). This is characteristic of a chondroblastoma. The preferred treatment for a chondroblastoma in a nonexpendable bone is intralesional curettage with or without local adjuvants (phenol, liquid nitrogen, argon beam coagulation) and bone grafting (or cement).

Some very aggressive chondroblastomas with soft-tissue extension, particularly those in the pelvis, may require en-bloc resection. Preferred Response # 81 is 1.

 

Question 82 An 11-year-old boy has a 6-month history of groin pain and a limp. A radiograph is shown in Figure 82a and a biopsy specimen is shown in Figure 82b. What is the etiology of the lesion?

1. Viral infection

2. G(s) alpha mutation 3- t(11;22)

4- t(X;18)

5- Posttraumatic

 

DISCUSSION: Fibrous dysplasia is a common benign skeletal lesion that may involve one bone (monostotic) or multiple bones (polyostotic) and occurs throughout the skeleton with a predilection for the long bones, ribs, and craniofacial bones. The etiology of fibrous dysplasia has been linked to an activating mutation in the gene that encodes the alpha subunit of stimulatory G protein (G(s)alpha) located at 20q13.2-13.3. The etiology for Paget's disease of bone is still unknown but growing evidence shows a possible link to a viral infection. t(11;22) is most commonly seen with Ewing's sarcoma and t(X;18) with synovial sarcoma. Preferred Respo# 82 is 2.

 

Question 83 What is the most common complication of total knee arthroplasty in patients with Paget disease?

1. Pain

2. Joint arthrosis

3. Pathologic fracture

4. Malalignment

5. Neurologic compromise

 

DISCUSSION: Paget disease affects 3% to 4% of the population in the US older than age 40 years. Urinary hydroxyproline and alkaline phosphatase are elevated in the lytic phase of disease. Insertion mutations in the TNFRSF11A gene encoding RANK are identified. The most common complication of total knee arthroplasty in patients with Paget disease is malalignment. The most frequent complication of hip surgery is hemorrhage. Joint arthrosis, pathologic fracture, and rarely neurologic compromise are sequelae of the disease process itself. The Preferred Response # 83 is 4.

 

Question 84 A 56-year-old woman has an 8 x 6 x 5 cm intramuscular anterior thigh soft-tissue mass. Biopsy shows a grade 3 undifferentiated pleomorphic sarcoma. A CT of the chest reveals no evidence of other lesions. According to the American Joint Commission on Cancer (AJCC) staging system, what is the stage of this tumor?

1- II-T1a 2- II-T1b 3- II-T2a 4- III 5- IV

 

DISCUSSION: The AJCC staging system for soft-tissue sarcomas is based on tumor grade, size, depth, and the presence of metastases. Stage I tumors are low grade. Stage II tumors are high grade. Grade is considered high grade for G3 or G4 tumors on a four-tier grading system and for G2 or G3 on a three-tier grading system. Size is designated by T1 for a size of less than or equal to 5.0 cm or T2 for a size of greater than 5.0 cm in maximal dimension. An 'a' or 'b' designation immediately follows the

 

size designation to distinguish between superficial (a) and deep (b) tumors. The "deep" designation applies to tumors that involve or are deep to the fascia. Stage III tumors are high grade, deep, and large (eg, T2b). Stage IV tumors include either N1 (nodal) or M1 (distant) metastases regardless of grade. Hence, stage II-T1a would refer to a high grade small superficial sarcoma. Stage II-T1b is a high grade small deep sarcoma. Stage II-T2a is a high grade large superficial tumor. The tumor presented in this case is high grade (G3 or G4), large (>5.0 cm), intramuscular (deep to the fascia), and without metastases. Hence, it is a stage III tumor.

 

The Preferred Response to Question # 84 is 4.

 

Question 85 Based on the radiographic findings and biopsy specimen shown in Figures 85a and 85b, what is the most likely diagnosis?

1. Ewing's sarcoma

2. Osteofibrous dysplasia

3. Chondromyxoid fibroma

4. Osteoid osteoma

5. Adamantinoma

 

DISCUSSION: Adamantinoma

is a low-grade malignant tumor with epithelial differentiation (cytokeratin positive). It can occur in other bones but is most common in the tibia. Cytokeratin is positive in most cases. Tumor metastases occur in up to 20% of patients. There is an association between adamantinoma and osteofibrous dysplasia. Ewing's sarcoma is a non-matrix producing medullary-based tumor associated with an aggressive periosteal reaction. Histologically it is a small round blue cell tumor. Osteofibrous dysplasia (OFD) is radiographically very similar to adamantinoma because both are cortically based and most common in the tibia. Histologically OFD is composed of bone trabeculae arranged as "chinese letters" with prominent osteoblastic rimming. There are no nests of epithelioid cells. Chondromyxoid fibroma is common in the anterior proximal tibia. It is medullary-based with subtle mineralization and causes thinning of the corticies. Osteoid osteoma is also most commonly periosteally or cortically based but is generally small (< 1cm) and has a sclerotic border.

 

The Preferred Response to Question # 85 is 5.

 

Question 86 Figures 86a and 86b show the radiograph and biopsy specimen of a 16-year-old boy who reports increasing right foot pain. What is the most likely diagnosis?

1. Enchondroma

2. Giant cell tumor 3- Chondrosarcoma

4. Chondromyxoid fibroma

5. Nonossifying fibroma

 

DISCUSSION: The radiograph

shows a benign-appearing bubbly radiolucent lesion with a narrow zone of transition and a thin rim of surrounding reactive bone. The biopsy specimen demonstrates spindle cells with a myxoid cartilaginous matrix. The diagnosis of the lesion is a chondromyxoid fibroma. This rare, benign tumor is usually painful and can be locally aggressive. Enchondroma is typically associated with calcifications and a bland hyaline cartilage on histology. Giant cell tumors are typically radiolucent without the bubbly appearance seen here and composed of multinucleated giant cells with stromal cells having similar nuclear morphology. Chondrosarcoma is uncommon in the hands and feet. Nonossifying fibromas can have a similar radiographic appearance but are histologically distinguished by a storiform pattern of bland fibroblasts with scattered giant cells. The Preferred Response to Question # 86 is 4.

 

Question 87 Figures 87a through 87c show the AP radiograph and coronal and axial MRI scans of a 50-year-old woman who has had right shoulder pain with overhead activity for the past 6 months. What is the most appropriate treatment of this lesion?

1- Observation with serial radiographs 2- Biopsy

3- Curettage and grafting 4- Wide resection

5- Chemotherapy followed by wide resection

 

DISCUSSION: The images show a mineralized lesion in the metaphysis of the proximal humerus, with no cortical disruption or endosteal scalloping. The mineralization pattern is suggestive of a hyaline cartilage neoplasm. There is no soft- tissue mass on the MRI scans. This is consistent with a benign enchondroma.

Observation is the treatment of choice for the lesion. Biopsy is not indicated and would be difficult to interpret. The other treatments listed are for low- or high-grade chondrosarcomas. Other explanations for the patient's shoulder pain, such as rotator cuff pathology or impingement, should be sought and treated.

The Preferred Response to Question # 87 is 1.

 

Question 88 A 51-year-old woman has shoulder pain after a minor fall. A radiograph, MRI scan, and bone scan are seen in Figures 88a through 88c. Biopsy specimens are seen in Figures 88d and 88e. What is the most likely diagnosis?

1. Osteosarcoma

2. Enchondroma

3. Fibrous dysplasia

4. Chondrosarcoma

5. Chondromyxoid fibroma

 

DISCUSSION: The radiograph shows an expansile, calcified tumor of the proximal humerus. The MRI scan shows an associated soft-tissue mass and the bone scan demonstrates increased uptake, although these findings could be associated with a pathologic fracture. Pathology is consistent with chondrosarcoma. Enchondroma could present with a similar pattern but should generally be smaller, less expansile, and have no soft-tissue extension; it is also less likely to be associated with a pathologic fracture. Additionally, the pathology would show more benign-appearing cartilage. Chondromyxoid fibroma is more typically eccentric and is associated with radiologic and pathologic findings consisting of benign chondroid, fibrous, and myxoid elements. The radiograph and pathology are not consistent with osteosarcoma or fibrous dysplasia.

The Preferred Response to Question # 88 is 4.

 

Question 89 Based on the lesion seen in Figure 89a and the biopsy specimen seen in Figure 89b, what is the most likely diagnosis?

 

1. Schwannoma

2. Nodular fasciitis

3. Lipoma

4. Hemangioma

5. Synovial sarcoma

 

DISCUSSION: The most reliable sign in diagnosing schwannoma is the percussion sign (radiating pain in the

affected nerve distribution on percussion of the lesion). Although sensory deficits are reported, motor weakness is rare. The sagittal MRI scan demonstrates both the string (attenuation of the nerve above and below the tumor) and target signs (circular low signal area within the mass). The biopsy specimen shows the palisading nuclei (Verocay bodies) typically seen in this disease. Nodular fasciitis is a benign tumor that arises in the deep fascia. It is fairly homogeneous and hyperintense on T2 pulse-weighted images and isointense to hypointense on corresponding T1 images. Lipoma is homogeneous bright on both T1 and T2 pulse-weighted images.

Hemangioma is usually intramuscular and heterogeneous because of vessel thrombosis and mineralization and adjacent interspersed fat. Synovial sarcoma is more often periarticular and located within muscle. It too can be very heterogeneous because of its cellularity, intralesional necrosis, collagenization, and mineralization. The Preferred Response # 89 is 1.

 

Question 90 What syndrome is characterized by polyostotic fibrous dysplasia, cafe- au-lait spots with serrated borders, endocrine abnormalities, and unilaterality?

1. Jaffe-Campanacci syndrome

2. Hunter's syndrome

3. Maffucci's syndrome

4. Multiple hereditary exostoses 5- McCune-Albright syndrome

 

DISCUSSION: This is a description for McCune-Albright syndrome. Jaffe-Campanacci syndrome is characterized by multiple nonossifying fibromas, cafe-au-lait spots, and the absence of neurofibromas. Hunter's syndrome is a mucopolysaccharidosis and lysosomal storage disease that affects all large joints with pain and decreased range

of motion. Maffucci's syndrome is associated with multiple hemangiomas and enchondromas. Multiple hereditary exostosis is characterized by the presence of multiple exostoses and is not associated with skin lesions or endocrine abnormalities. The Preferred Response to Question # 90 is 5.

 

Question 91 A 25-year-old man has had low back pain for the past 4 months. An AP pelvis radiograph, CT scan, MRI scan, and biopsy specimen are shown in Figures 91a through 91d. What is the most likely diagnosis?

1- Giant cell tumor 2- Chordoma

3. Osteosarcoma

4. Hemangioma

5. Rectal adenocarcinoma

 

DISCUSSION: Imaging shows a lesion in the sacrum, with extension out of the bone. Histology shows multinucleated giant cells with deposits of hemosiderin. This is consistent with giant cell tumor. Chordoma commonly occurs in the sacrum as a midline lesion of notocord remnants, but the histology would show physaliferous cells. Osteosarcoma occasionally occurs in the sacrum, but histology would show malignant cells and osteoid. Hemangiomas in the spine are typically small, intraosseus lesions with vertical striations. Rectal adenocarcinoma would originate anterior to the sacrum and show a glandular pattern on biopsy.Pre Res # 91 is 1.

 

Question 92 An 11-year-old boy reports pain after throwing a ball in gym class. He denies prior pain in the arm. Radiographs of the humerus are shown in Figures 92a and 92b. What is the next most appropriate step in management?

 

1- Staging studies (MRI, bone scan, and chest CT) 2- Open biopsy

3- Sling and closed fracture care 4- Curettage and bone grafting

5- Open reduction and internal fixation

 

DISCUSSION: The radiographs reveal a fracture through a lesion of the proximal humerus. The central lucency without any obvious matrix and thinning of the cortical bone are typical findings of an unicameral bone cyst. The proximal humerus is the most common site for this lesion. Typically these fractures should be allowed to heal prior to treatment, which may include, classically, aspiration and injection of corticosteroid. Recently other treatment options, including the injection of bone marrow aspirate or bone graft substitutes, have been reported, with open curettage and bone grafting reserved only for recurrent or nonresponding cysts. The Preferred Response to Question # 92 is 3.

 

Question 93 Figures 93a through 93d show the MRI scan, CT scans, and a biopsy specimen of a 23-year-old woman who reports left-sided back pain that travels around the lateral aspect of the thigh and down the lateral aspect of the left leg. The pain is relieved with anti-inflammatory medications. It is not associated with weight bearing. What is the most likely diagnosis?

1. Osteosarcoma

2. Osteoblastoma 3- Giant cell tumor

4- Aneurysmal bone cyst 5- Stress fracture

 

DISCUSSION: Osteoblastoma is a bone-forming lesion characterized by a mixed lytic- blastic lesion of variable size greater than 2 centimeters. Histology shows osteoid formation with benign rimming osteoblasts and an intervening highly vascular stroma. Osteosarcoma can look similar radiographically but histology typically shows malignant spindle cells interspersed in osteoid. Giant cell tumor histology shows multiple multinucleated giant cells in a background stroma of stromal cells with similar nuclei. Aneurysmal bone cyst typically has lakes of blood surrounded by a thin benign fibrous membrane. Stress fracture does not typically have a large lucent central lesion on radiographs. The Preferred Response to Question # 93 is 2.

 

Question 94 What is the primary problem in rickets osteomalacia? 1- Defect in the zone of proliferation within the physis

2- Defect in type I collagen 3- Defect in the ext-1 gene 4- Low level of calcium

5- Production of dysplastic fibrous bone

 

DISCUSSION: Rickets is a disorder of bones in children that results from decreased calcium available in the blood resulting in poor mineralization of bone that can lead to fractures and deformity. The most common cause of rickets is from vitamin D deficiency but it can also be caused by poor nutrition or gastrointestinal disease that results in poor calcium absorption such as celiac disease or severe diarrhea from other causes. Rickets is not primarily a physeal disorder. Osteogenesis imperfecta is caused by a defect in type I collagen. A defect in the ext-1 gene is often seen in patients with multiple hereditary exostoses. Fibrous dysplasia also can result in bone deformity and fractures due to production of dysplastic fibrous bone but is not caused by calcium or vitamin D deficiency. The Preferred Response # 94 is 4.

 

Question 95 A 42-year-old man has pain and swelling about his knee that has been worsening over the last 6 months. Examination shows an effusion, bogginess in the suprapatellar pouch, and a decrease in range of motion when compared to the contralateral knee. Radiographs are shown in Figures 95a and 95b and a sagittal MRI scan is shown in Figure 95c. A biopsy specimen is shown in Figure 95d. What is the most appropriate treatment for this lesion to minimize the risk of local recurrence?

1. Observation

2. Intra-articular injection of methylprednisolone 3- Limited arthroscopic synovectomy

4- Open anterior and posterior synovectomy 5- Intra-articular injection of radioisotope

 

DISCUSSION: The clinical presentation, radiographic studies, and biopsy specimen are all consistent with pigmented villonodular tenosynovitis (PVNS). Most agree that the lowest chance of recurrence for diffuse PVNS of the knee is with open anterior and posterior synovectomy. However, this can be associated with significant morbidity. Arthroscopic synovectomy, while associated with a higher recurrence rate, is preferred by some due to lower morbidity. Regardless of the aggressiveness of synovectomy, the recurrence rate of diffuse PVNS remains significant. The cause of PVNS is controversial, but most believe it is a non-neoplastic inflammatory process that results in intra-articular synovial thickening, bloody effusion, pain, and even intraosseous erosion. Intra-articular radioisotopes have been removed from the market because of the risk of hematomyelopoetic diseases. Observation alone will likely lead to disease progression and joint destruction. Intra-articular steroids will not halt the progression of PVNS and, therefore have no role in its treatment.

The Preferred Response to Question # 95 is 4.

 

Question 96 Acral bone metastases (to the hands and feet) are most likely the result of a primary solid organ tumor in which of the followings structures?

1- Liver 2- Lung 3- Breast 4- Thyroid 5- Prostate

 

DISCUSSION: Lung cancer is the most likely solid organ cancer to metastasize distal to the elbow and the knees. The most common sites for metastatic disease are the vertebral bodies, pelvis, and long bones. Genitourinary tumors may also metastasize to distal sites. The Preferred Response to Question # 96 is 2.

 

Question 97 A 13-year-old girl has had a painless thigh mass for the past 3 months. A biopsy is performed and chromosome analysis reveals a t(X;18)(p11:q11) translocation (involving the genes SYT-SSX). What is the most likely diagnosis?

1. Liposarcoma

2. Synovial sarcoma

3. Myxoid chondrosarcoma

4. Gastrointestinal stromal tumor 5- Malignant fibrous histiocytoma

 

DISCUSSION: Although synovial sarcoma accounts for 6% of all soft-tissue sarcomas, it represents 16% of soft-tissue sarcomas in adolescents and young adults, making it and rhabdomyosarcoma (which accounts for 15%) the most common soft-tissue sarcomas in this age group. The (X;18)(p11:q11) translocation is characteristic of synovial sarcoma. Myxoid chondrosarcomas often demonstrate a t(9;22)

 

translocation. Well-differentiated liposarcomas and malignant fibrous histiocytomas may demonstrate a ring form of chromosome 12. Gastrointestinal stromal tumors may exhibit monosomies of chromosomes 14 and 22. Preferred Respon # 97 is 2.

 

Question 98 Figures 98a through 98c show the radiograph, MRI scan, and biopsy specimen of a 13-year-old girl who reports increasing right ankle pain for the past 2 months. Work-up reveals no other lesions. What is the most appropriate treatment for this patient?

 

1. Surgery alone

2. Radiation therapy alone 3- Chemotherapy alone

4. Surgery and radiation therapy

5. Surgery and chemotherapy, with or without radiation therapy

 

DISCUSSION: The imaging studies show a permeative destructive lesion of the distal fibula with periosteal reaction. The biopsy specimen demonstrates a small blue cell tumor consistent with Ewing's sarcoma. The most appropriate treatment for this patient would be a combination of surgery and chemotherapy. Local control of Ewing's sarcoma is usually achieved by surgery with wide margins. In some cases, radiation therapy can be used for local control if wide resection would be associated with unacceptable morbidity. Chemotherapy, however, is required in all cases to treat systemic disease even if no metastases are revealed on the initial work-up.

 

The Preferred Response to Question # 98 is 5.

 

Question 99 When compared with postoperative external beam radiation therapy for the treatment of soft-tissue sarcomas, preoperative radiation therapy is associated with which of the following?

1- Higher wound complications 2- Higher doses of radiation

3- Larger volumes of tissue irradiated 4- Worse overal