ABOS Shoulder MCQs Set 2: Cuff, Instability & Fractures

Question 1

A 37-year-old electrician is diagnosed with a frozen shoulder after sustaining an electrical injury at work 2 weeks ago. Examination reveals that he cannot actively or passively externally rotate or abduct the arm. The glenohumeral joint and scapula move in a 1:1 ratio. Radiographs are shown in Figures 15a and 15b. The best course of action should be

Explanation

The patient's history, examination, and radiographs are classic for locked posterior dislocation of the glenohumeral joint. Posterior dislocation of the shoulder remains the most commonly missed dislocation of a major joint. Up to 80% are missed on initial presentation. The primary cause for failure to accurately diagnose this injury is inadequate radiographic evaluation. The typical presentation is a shoulder locked in internal rotation with loss of abduction. An axillary view not only will make the definitive diagnosis but will help assess the size of the articular surface defect and help plan treatment. This view can be done expediently as part of every trauma series. The AP view is suspicious for a posteriorly dislocated humerus with loss of the humeral neck profile, a vacant glenoid sign, and an anterior humeral head compression fracture (reverse Hill-Sachs lesion). Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18. Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosement, IL, American Academy of Orthopaedic Surgeons, 1997, pp 181-189.

Question 2

An 80-year-old man has had increasing shoulder pain for the past 4 months. He reports that it began with soreness and stiffness after chopping some wood. A coronal MRI scan is shown in Figure 16. Initial management should consist of

Explanation

The MRI scan shows a massive tear of the supraspinatus tendon with medial retraction to the level of the glenoid. This is most likely an attritional tear with a high risk of failure of the repair. The preferred treatment is nonsurgical management for pain and stiffness. Acromioplasty and coracoacromial ligament release in this setting are controversial, as they can result in the devastating complication of anterosuperior subluxation of the humerus. Rockwood CA Jr, Williams GR Jr, Burkhead WZ Jr: Debridement of degenerative, irreparable lesions of the rotator cuff. J Bone Joint Surg Am 1995;77:857-866.

Question 3

Figure 17 shows the radiograph of a 25-year-old professional football player who has superior shoulder pain that prevents him from sports participation. History reveals that he sustained a shoulder injury that was treated with closed reduction and temporary pinning 3 years ago. The best course of action should be

Explanation

The radiograph shows a complete acromioclavicular separation. Because the patient is a professional athlete who is unable to participate, surgery is indicated. Chronic separations, especially those with previous trauma from joint pinning, should be treated with resection of the distal clavicle and stabilization to the coracoid. Some type of biologic reconstruction of the coracoclavicular ligaments is generally recommended. Open repair of the ligaments is generally not possible in such a delayed fashion. Screw fixation alone will not provide a lasting solution as the screws usually need to be removed, leaving no fixation in place. Reconstruction using the coracoacromial ligament is generally recommended with coracoclavicular fixation to protect the repair while it heals. Nuber GW, Bowen MK: Disorders of the acromioclavicular joint: Pathophysiology, diagnosis and management, in Iannotti JP, Williams GR (eds): Disorders of the Shoulder: Diagnosis and Management. Philadelphia, PA, Lippincott Williams and Wilkins, 1999.

Question 4

A 54-year-old man undergoes total shoulder arthroplasty for osteoarthritis. Despite compliance with an early passive range-of-motion exercise program, he does not regain more than 90 degrees of elevation, 10 degrees of external rotation, and has internal rotation to the fifth lumbar vertebra. At 6 months, his motion fails to improve. Radiographs are shown in Figures 18a and 18b. What is the best course of action?

Explanation

The patient has a global loss of motion that has failed to improve with 6 months of nonsurgical treatment; because he has reached a plateau, further nonsurgical management will likely be ineffective. Revision in the form of an open release is indicated to lyse intra- and extra-articular adhesions; subscapularis lengthening may be done concurrently as needed. Revising to a smaller head can be considered if adequate motion is not achieved. The radiographs reveal an adequate neck cut with appropriate seating of the component. Removing the glenoid component will decrease capsular tension but will probably increase pain because of the lack of glenoid resurfacing. Increasing humeral retroversion will not improve motion. Cuomo F, Checroun A: Avoiding pitfalls and complication in total shoulder arthroplasty. Orthop Clin North Am 1998;29:507-518.

Question 5

A 47-year-old patient has had persistent pain and weakness after undergoing a reamed intramedullary nailing for a midshaft humerus fracture 8 months ago. There is no evidence of infection. Radiographs are shown in Figures 19a and 19b. Management should consist of

Explanation

Compression plating remains the treatment of choice for most established humeral nonunions. Autograft is felt to be superior to allograft. Electrical stimulation has not been found to improve healing rates in patients with nonunion after intramedullary nailing. Retrograde nailing with flexible nails gives inadequate rotational control to promote healing in this patient. Adding cancellous graft alone will not stabilize the nonunion site. Dynamic locking has been successful only in the lower extremity because the bone can be loaded axially. McKee MD, Miranda MA, Riemer BL, et al: Management of humeral nonunion after the failure of locking intramedullary nails. J Orthop Trauma 1996;10:492-499.

Question 6

An 18-year-old man sustained closed humeral shaft and forearm fractures of his dominant arm in a motor vehicle accident. Neurovascular examination is intact, and his condition is stable. The best course of action for management of the injuries should be

Explanation

Fractures above and below the elbow constitute floating elbow injuries and are best treated with internal fixation to allow early range of motion and to prevent elbow stiffness. Use of a long arm cast would promote elbow stiffness. External fixation is indicated primarily for open injuries. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.

Question 7

A 32-year-old woman has had pain and a visibly growing mass in the shoulder for 3 years but denies any history of trauma. Examination reveals a swollen, boggy shoulder mass. The AP radiograph and MRI scan are shown in Figures 20a and 20b. Figures 20c through 20e show a portion of the excised mass and the photomicrographs of the biopsy specimen. What is the most likely diagnosis?

Explanation

The radiographic findings are classic for synovial chondromatosis because of the small calcified opacities within the joint surrounding the synovium. The histologic findings show cartilaginous foci of metaplasia, which may be markedly cellular. However, unlike low-grade chondrosarcoma, it lacks cellular and nuclear pleomorphism. Murphy FP, Dahlin DC, Sullivan CR: Articular synovial chondromatosis. J Bone Joint Surg Am 1982;44:77-86.

Question 8

What is the most important factor regarding the risk of recurrent instability in a patient with an acute anterior dislocation of the shoulder?

Explanation

The recurrence rate of anterior dislocation of the shoulder after the first episode in athletes younger than age 20 years is thought to be as high as 90%, making surgery after the initial episode a consideration. The rate drops from 50% to 75% in the 20- to 25-year age group and down to 15% in patients older than age 40 years. An excellent prospective study of 257 patients in Sweden showed that there was no difference in those who did or did not complete 3 weeks of immobilization. The study also showed variability among different age groups in the importance of athletic participation; athletes in the 12- to 22-year age group had a higher recurrence rate, whereas the more sedentary patients in the 23- to 29-year age group had a higher rate. Hovelius L: The natural history of primary anterior dislocation of the shoulder in the young. J Orthop Sci 1999;4:307-317.

Question 9

A 25-year-old man injured his dominant shoulder after falling on his outstretched arm 4 months ago. Examination reveals that he cannot lift his arm above 90 degrees, and he has pronounced medial scapular winging. Management should consist of

Explanation

Serratus anterior palsy or long thoracic nerve palsy is usually caused by traction injury to the nerve, blunt injury, or iatrogenic injury. The palsy results in winging of the scapula and medial rotation of the inferior pole of the scapula. A patient with this injury will usually recover in 12 to 18 months. Initial treatment should include observation and shoulder strengthening exercises. Nerve exploration with repair has not proven beneficial in changing the outcome. Many orthopaedic surgeons favor using a split pectoralis major transfer for symptomatic patients. Electrodiagnostic studies are helpful in confirming the diagnosis. Post M: Pectoralis major transfer for winging of the scapula. J Shoulder Elbow Surg 1995;4:1-9.

Question 10

Treatment of adhesive capsulitis has a high failure rate when the underlying cause is

Explanation

Diabetes mellitus has been associated with resistant cases of adhesive capsulitis. With other causes of onset, adhesive capsulitis frequently responds to nonsurgical management such as stretching exercises or, when this fails, manipulation under anesthesia and/or arthroscopic release. Manipulation is rarely successful for the treatment of adhesive capsulitis associated with diabetes mellitus, and arthroscopic release may be preferred. Fisher L, Kurtz A, Shipley M: Association between cheiroarthropathy and frozen shoulder in patients with insulin-dependent diabetes mellitus. Br J Rheumatol 1986;25:141-146. Janda DH, Hawkins RJ: Shoulder manipulation in patients with adhesive capsulitis and diabetes mellitus: A clinical note. J Shoulder Elbow Surg 1993;2:36-38.

Question 11

Figure 21 shows the AP radiograph of a 41-year-old patient who sustained a closed bicolumnar fracture of the distal humerus that resulted in a painful nonunion. What is the best initial construct for rigid stabilization of this fracture pattern?

Explanation

The dual plate fixation construct is significantly stronger than single plate or "Y" plate fixation. Two-plate constructs at right angles, the ulnar plate medially and the lateral plate posteriorly, would appear to be biomechanically optimal. This approach usually is feasible at the time of surgery. Clinically, dual 3.5-mm reconstruction or dynamic compression plates are superior to one third tubular plate fixation. Supplementary external fixation is not considered a better treatment option. Failure of fixation and nonunion are often the result of inadequate fixation and osteoporosis. Helfet DL, Hotchkiss RN: Internal fixation of the distal humerus: A biomechanical comparison of methods. J Orthop Trauma 1990;4:260-264.

Question 12

Figure 22 shows the radiographs of a 16-year-old boy who injured his elbow in a fall 1 year ago. Although he has no pain, he reports restricted forearm rotation and elbow flexion. What is the most likely diagnosis?

Explanation

Congenital dislocation of the radial head is often confused with posttraumatic dislocation. The distinguishing feature here is the dome-shaped radial head. Some patients with congenital anomalies fail to recognize their limitations until an injury occurs. Soft-tissue contractures do not cause radial head dislocation nor do they usually cause this pattern of motion restriction (mainly flexion and rotation without significant loss of extension). There is no deformity of the ulna to suggest an old Monteggia lesion. Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, p 196.

Question 13

A 55-year-old man has had progressive right shoulder pain for the past 2 years. Examination reveals active elevation to 120 degrees, external rotation to 20 degrees, and internal rotation to the sacrum. AP and axillary radiographs are shown in Figures 23a and 23b. Which of the following procedures would result in the most predictable long-term pain relief?

Explanation

Total shoulder arthroplasty yields excellent pain relief and function in patients with osteoarthritis. It is favored over humeral arthroplasty, especially when there is asymmetric posterior glenoid wear and posterior humeral subluxation as shown on the axillary radiograph. Arthroscopic debridement of the glenohumeral joint may be helpful in delaying the need for arthroplasty when the arthritic changes are mild to moderate but is not indicated for advanced osteoarthritis. Cofield RH, Frankle MA, Zuckerman JD: Humeral head replacement for glenohumeral arthritis. Semin Arthroplasty 1995;6:214-221. Levine WN, Djurasovic M, Glasson JM, Pollock RG, Flatow EL, Bigliani LU: Hemiarthroplasty for glenohumeral osteoarthritis: Results correlated to degree of glenoid wear. J Shoulder Elbow Surg 1997;6:449-454.

Question 14

A 20-year-old professional baseball pitcher has had a 3-year history of increased aching in his shoulder that is associated with pitching, and he is now seeking a second opinion. Nonsurgical management consisting of rest, anti-inflammatory drugs, ice, heat, and cortisone injections has failed to provide relief. A previous work-up that included radiographs and gadolinium-enhanced MRI arthrography was negative. Results of an arteriogram suggest quadrilateral space syndrome. Assuming that this is the correct diagnosis, what nerve needs to be decompressed?

Explanation

Quadrilateral space syndrome is a rare condition and is the result of compression of the contents of the quadrilateral space. The contents of the quadrilateral space include the posterior circumflex vessels and the axillary nerve. Cahill BR, Palmer RE: Quadrilateral space syndrome. J Hand Surg 1983;8:65-69.

Question 15

A right-handed 24-year-old woman underwent an arthroscopic Bankart repair for recurrent anterior dislocations 9 months ago. Despite extensive physical therapy for 8 months, the patient has very limited range of motion (elevation to 130 degrees and external rotation to 10 degrees with the arm at the side). Shoulder radiographs are normal. The next step in management should consist of

Explanation

Arthroscopic capsular release is an effective means of treating stiffness that is the result of capsular contractures, such as in the case of a tight Bankart repair. Open release allows lengthening of a surgically shortened subscapularis, such as after a tight Putti-Platt repair. Additional physical therapy is unlikely to be effective because 8 months of treatment has failed to result in improvement. Accepting this degree of asymptomatic limited motion is not advisable because of the functional limitations for the patient and the increased risk of postoperative degenerative arthritis. Warner JJ, Allen AA, Marks PH, Wong P: Arthroscopic release of postoperative capsular contracture of the shoulder. J Bone Joint Surg Am 1997;79:1151-1158.

Question 16

A patient with deficient anteroinferior bone stock undergoes a Latarjet procedure that transfers a portion of the coracoid to the glenoid rim and secures it with two screws. After surgery, the patient reports numbness on the anterolateral forearm. To verify the diagnosis, what muscle should be tested for strength?

Explanation

A Latarjet procedure is similar to a Bristow procedure, but with the Latarjet procedure a larger portion of the coracoid is transferred to the scapular neck at the anteroinferior glenoid. As in a Bristow procedure, if the fragment is pulled or twisted during the dissection or during fixation, the musculocutaneous nerve can be injured. With loss of biceps function, elbow flexion and forearm supination will be weaker. Ho E, Cofield RH, Balm MR, Hattrup SJ, Rowland CM: Neurologic complications of surgery for anterior shoulder instability. J Shoulder Elbow Surg 1999;8:266-270. Boardman ND 3rd, Cofield RH: Neurologic complications of shoulder surgery. Clin Orthop 1999;368:44-53.

Question 17

A 34-year-old woman has had painful snapping and popping in the elbow since falling while in-line skating 6 months ago. The popping also occurs when she pushes off with her hands to rise from a seated position. Initial radiographs were normal, and she was told that she had sprained her elbow. Examination reveals few findings except that she is very apprehensive when the forearm is forcefully supinated with the elbow extended or partially flexed. A radiograph taken in that position is shown in Figure 24. Treatment should consist of

Explanation

The radiograph reveals posterolateral rotatory subluxation of the radiohumeral and ulnohumeral joints. The space between the ulna and trochlea is enlarged, particularly posteriorly at the olecranon. These findings are diagnostic of posterolateral rotatory instability, which causes recurrent subluxation and reduction as the elbow is flexed from an extended and supinated position with valgus load. The posterolateral rotatory instability apprehension test was performed on this patient and the result was positive. The lateral pivot-shift test causes a clunk as the elbow reduces but is more difficult to perform, even under general anesthesia. The patient does not have isolated subluxation of the radial head, although these findings can be mistakenly diagnosed as such. The radial head is normally shaped and does not represent a congenital dislocation. There are no findings here to suggest osteochondritis dissecans or loose bodies. O'Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446. Burgess RC, Sprague HH: Post-traumatic posterior radial head subluxation: Two case reports. Clin Orthop 1984;186:192-194.

Question 18

A 49-year-old woman noted pain in her right axilla 1 day after moving heavy furniture. Two weeks later, she now reports persistent numbness and paresthesias along the inner aspect of her upper arm radiating into the ulnar digits. Examination reveals full shoulder motion, tenderness over the first rib, and a decreased radial pulse with the shoulder placed overhead. What is the most likely diagnosis?

Explanation

Thoracic outlet syndrome is thought to be caused by compression of the neurovascular supply to the upper limb in the supraclavicular and axillary regions of the shoulder. While typically progressive in onset, thoracic outlet syndrome may develop after acute injury. Injury or weakness of the scapular muscles, especially the trapezius, may result in descent of the scapula and cause compression of the thoracic outlet. In general, most symptoms are the result of neural compression. Typical symptoms include pain in the neck or shoulder and numbness or tingling that predominantly involves the ulnar side of the arm and hand. Exacerbation of these symptoms is typical when the arm is abducted. Initial management should consist of postural exercises aimed at restoring proper scapular stability. Severe recalcitrant symptoms may warrant surgical decompression. Leffert RD: Thoracic outlet syndrome. J Am Acad Orthop Surg 1994;2:317-325.

Question 19

A patient has had a locked posterior dislocation of the shoulder for the past 6 months. After undergoing total shoulder arthroplasty that includes adequate anterior releases and posterior capsulorrhaphy, the patient still exhibits posterior instability intraoperatively. The postoperative rehabilitation regimen should include

Explanation

Achieving stability in chronic locked posterior dislocations of the shoulder remains a difficult challenge. Intraoperative measures include decreased humeral retroversion, anterior releases, and posterior capsular tightening. Postoperative rehabilitation is of equal importance. Immobilization in an external rotation brace (10 degrees to 15 degrees) with the arm at the side for 4 to 6 weeks is recommended to decrease tension in the posterior capsule. When passive range-of-motion exercises are instituted, they should be performed in the plane of the scapula to avoid stress posteriorly. Internal rotation and supine elevation should be avoided for similar reasons. Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18.

Question 20

Which of the following factors is associated with failure of arthroscopic excision of the distal clavicle?

Explanation

Uneven resection of bone, typically leaving a retained posterolateral corner of the distal clavicle, can lead to failure of arthroscopic distal clavicle excision. The amount of bone resected, the gender of the patient, or the diagnosis (osteoarthritis versus osteolysis) does not appear to affect the results.

Question 21

Anterior subluxation in a throwing athlete is most commonly the result of

Explanation

Subtle anterior subluxation in the throwing athlete most frequently results from excessive capsular laxity because of repetitive microtrauma. Avulsion of the inferior glenohumeral ligament from the glenoid, or more rarely from the humerus, occurs with macrotrauma. A large Hill-Sachs lesion and a glenoid rim fracture also may result from a traumatic anterior dislocation. Kvitne RS, Jobe FW: The diagnosis and treatment of anterior instability in the throwing athlete. Clin Orthop 1993;291:107-123.

Question 22

What is the most significant prognostic factor in nontraumatic osteonecrosis of the humeral head?

Explanation

Use of systemic steroids has been implicated in the development of nontraumatic osteonecrosis of the humeral head. Staging of the disease is most relevant to prognosis and treatment. Cruess has described a widely accepted staging system. Several authors have shown that patients who have a lower stage of disease (ie, stage I or II) have a much less likely chance of progression compared with those who are in the later stages (IV and V). Cruess RL: Osteonecrosis of bone: Current concepts as to etiology and pathogenesis. Clin Orthop 1986;208:30-39. Cruess RL: Steroid-induced avascular necrosis of the humeral head: Natural history and management. J Bone Joint Surg Br 1976;58:313-317. Rutherford CS, Cofield RH: Osteonecrosis of the shoulder. Orthop Trans 1987;11:239.

Question 23

A 43-year-old former professional hockey player reports severe pain in his chest after being checked from the side in a pick-up hockey game. An MRI scan and plain radiographs are shown in Figures 25a through 25c. What is the most likely diagnosis?

Explanation

Anterior dislocation is the most common type of sternoclavicular dislocation. The medial end of the clavicle is displaced anterior or anterosuperior to the anterior margin of the sternum. In a study by Omer, 31% of athletic injuries have been known to cause a dislocation of the sternoclavicular joint. The serendipity view can show this dislocation, as will CT of the chest. This view requires the x-ray beam to be aimed at the manubrium with 40 degrees of cephalic tilt. An anterior sternoclavicular joint dislocation will appear superiorly displaced, while a posterior sternoclavicular joint dislocation is inferiorly displaced on the serendipity view. Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1998, vol 1, pp 566-572.

Question 24

Which of the following is considered a contraindication to functional bracing for the treatment of humeral shaft fractures?

Explanation

Most closed humeral shaft fractures and fractures caused by a low-velocity hand gun can be managed nonsurgically with closed reduction and application of a coaptation splint followed by a functional brace. Contraindications to use of the functional brace include: 1) massive soft-tissue or bone loss; 2) an unreliable or noncompliant patient; and 3) an inability to maintain acceptable fracture alignment of up to 20 degrees of anterior or posterior angulation, 30 degrees of varus or valgus angulation, and greater than 3 cm of shortening. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286. Pollock FH, Drake D, Bovill EG, Day L, Trafton PG: Treatment of radial neuropathy associated with fractures of the humerus. J Bone Joint Surg Am 1981;63:239-243.

Question 25

A 20-year-old man with fascioscapulohumeral dystrophy has severe scapular winging of both shoulders. He can no longer abduct above 80 degrees, and it affects his activities of daily living. A clinical photograph is shown in Figure 26. Definitive management should consist of

Explanation

The patient's history is typical of patients with severe fascioscapulohumeral dystrophy. The scapular winging can be so pronounced that there is significant loss of function of the upper extremity. The surgical options include transfer of the pectoralis major muscle with a tendon graft or scapulothoracic fusion. The latter is a technically demanding procedure but can provide a very stable platform for the upper extremity. Most patients will see increased elevation of the extremity once the scapula is stabilized. Pectoralis minor transfer has not been described and would not be effective. Shapiro F, Specht L: The diagnosis and orthopaedic treatment of inherited muscular diseases of childhood. J Bone Joint Surg Am 1993;75:439-454.

Question 26

An 75-year-old female presents with chronic right shoulder pain, limited active elevation to 45 degrees, and a positive hornblower's sign. Radiographs demonstrate superior migration of the humeral head and acetabularization of the acromion.

What is the most appropriate definitive management?

Explanation

Reverse total shoulder arthroplasty is the treatment of choice for rotator cuff arthropathy with pseudoparalysis, relying on the deltoid to elevate the arm. Hemiarthroplasty is historically an option but provides less predictable functional recovery, and anatomic arthroplasty is contraindicated due to glenoid component rocking (rocking horse effect).

Question 27

A 22-year-old rugby player presents with recurrent anterior shoulder instability. CT scan indicates 25% glenoid bone loss and an engaging Hill-Sachs lesion. What is the most appropriate surgical intervention?

Explanation

An open Latarjet procedure (coracoid transfer) is indicated for patients with recurrent anterior shoulder instability and significant glenoid bone loss (>20-25%). Soft tissue repairs alone in the setting of critical bone loss have an unacceptably high failure rate.

Question 28

A 30-year-old male bodybuilder reports dull, aching posterior shoulder pain and weakness in external rotation. MRI reveals a paralabral cyst at the spinoglenoid notch. Which muscle is primarily affected?

Explanation

A cyst at the spinoglenoid notch typically compresses the suprascapular nerve after it has innervated the supraspinatus, leading to isolated infraspinatus weakness and atrophy. Cysts at the suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 29

A 45-year-old male presents with shoulder pain and inability to externally rotate his arm after a generalized seizure. An axillary radiograph shows a posterior shoulder dislocation with a reverse Hill-Sachs lesion involving 35% of the articular surface.

The dislocation is reduced. What is the most appropriate management?

Explanation

For an anteromedial humeral head defect (reverse Hill-Sachs) involving 20-40% of the articular surface, transfer of the lesser tuberosity or subscapularis into the defect (McLaughlin procedure or modification) is indicated to prevent recurrent posterior instability.

Question 30

A 55-year-old man falls on an outstretched hand and presents with weakness in internal rotation. He has a positive belly-press test and increased passive external rotation compared to the contralateral side. Which structure is most likely injured?

Explanation

The belly-press test and increased passive external rotation are classic signs of a subscapularis tendon tear. This injury often follows an acute traumatic event, such as a fall, in an older adult.

Question 31

In reverse total shoulder arthroplasty (RTSA), moving the center of rotation medially and distally relative to the native joint serves to:

Explanation

Medializing and distalizing the center of rotation in an RTSA increases the deltoid moment arm and places the muscle under greater tension. This allows the deltoid to efficiently elevate the arm in the absence of a functioning rotator cuff.

Question 32

A 22-year-old collegiate rugby player presents with recurrent anterior shoulder instability. A pre-operative computed tomography (CT) scan with 3D reconstruction reveals an anterior inferior glenoid bone defect measuring 26% of the native glenoid width. What is the most appropriate surgical management?

Explanation

The Latarjet procedure is indicated for patients with recurrent anterior instability and critical glenoid bone loss (>20-25%). Arthroscopic soft tissue stabilization in the setting of critical bone loss carries an unacceptably high failure rate.

Question 33

A 45-year-old male presents with vague posterolateral shoulder pain and weakness. Magnetic resonance imaging (MRI) reveals a large paralabral cyst at the spinoglenoid notch compressing the traversing nerve. Which of the following physical examination findings is most likely present?

Explanation

The suprascapular nerve innervates the supraspinatus and infraspinatus. Entrapment at the spinoglenoid notch affects only the branch to the infraspinatus, leading to isolated external rotation weakness without abduction deficits.

Question 34

Recent anatomical studies and perfusion analyses (such as those by Hertel) regarding proximal humerus fractures have demonstrated that the primary blood supply to the humeral head is derived from which of the following?

Explanation

Historically, the anterior humeral circumflex artery was considered the primary supply. However, recent studies demonstrate that the posterior humeral circumflex artery provides the majority of the blood supply to the humeral head.

Question 35

A 60-year-old man feels a sudden pop in his shoulder while lifting a heavy box. On examination, he has a positive belly-press test and increased passive external rotation compared to the contralateral side. Which structure has most likely been ruptured?

Explanation

A positive belly-press test and increased passive external rotation are classic physical exam findings indicating a rupture of the subscapularis tendon. The subscapularis is the primary internal rotator of the shoulder.

Question 36

A 75-year-old female sustains a comminuted 4-part proximal humerus fracture. Radiographs and CT show significant osteopenia, severe tuberosity comminution, and a head-split component. What is the most appropriate definitive surgical treatment?

Explanation

Reverse total shoulder arthroplasty is the preferred treatment in elderly patients with complex 4-part fractures and head-split components. It relies less on tuberosity healing for functional overhead elevation compared to hemiarthroplasty.

Question 37

Which of the following radiographic criteria is most strongly predictive of humeral head ischemia and avascular necrosis following a proximal humerus fracture?

Explanation

Hertel described criteria predictive of humeral head ischemia, which include a metaphyseal head extension (calcar length) of less than 8 mm and disruption of the medial calcar hinge. These disrupt the critical blood supply.

Question 38

A 25-year-old male requires surgery for recurrent anterior shoulder instability. Diagnostic arthroscopy reveals an engaging Hill-Sachs lesion and a 12% anterior glenoid bone defect. Which of the following procedures is most appropriate?

Explanation

For subcritical glenoid bone loss (<15-20%) accompanied by an engaging (off-track) Hill-Sachs lesion, arthroscopic Bankart repair combined with remplissage effectively restores stability and prevents engagement.

Question 39

A 45-year-old construction worker presents with deep anterior shoulder pain. MRI arthrogram reveals an isolated Type II SLAP tear. He has failed 6 months of physical therapy and injections. What is the most appropriate surgical intervention?

Explanation

In patients older than 40 years, especially laborers, biceps tenodesis is favored over SLAP repair for Type II tears. SLAP repairs in this demographic carry a higher risk of postoperative stiffness and persistent pain.

Question 40

A 35-year-old male presents to the emergency department after a generalized tonic-clonic seizure. His arm is locked in internal rotation and he has severe pain with any attempt at external rotation. Anteroposterior (AP) radiograph shows a 'lightbulb sign'. What is the most likely diagnosis?

Explanation

Posterior shoulder dislocations commonly occur after seizures or electrical shocks due to the powerful internal rotators overpowering the external rotators. They clinically present with the arm locked in internal rotation and show a 'lightbulb' appearance on AP radiographs.

Question 41

A 40-year-old recreational tennis player has an MRI demonstrating a partial articular supraspinatus tendon avulsion (PASTA) involving 60% of the tendon footprint. He has failed conservative management. What is the recommended surgical management?

Explanation

For articular-sided partial rotator cuff tears involving greater than 50% of the tendon thickness, surgical repair is indicated. This can be performed either by completing the tear followed by a formal repair, or via a transtendon technique.

Question 42

On a coronal T2-weighted MRI of the shoulder in a patient with recurrent instability, the normal U-shaped axillary pouch is disrupted and appears as a 'J-sign'. This finding is pathognomonic for which of the following lesions?

Explanation

The 'J-sign' on a coronal MRI indicates a Humeral Avulsion of the Glenohumeral Ligament (HAGL) lesion. The normal axillary recess loses its U-shape due to the capsular avulsion from the humeral neck.

Question 43

A 32-year-old male sustains a severe blunt trauma to his shoulder resulting in a scapular body fracture. Which of the following is considered an indication for open reduction and internal fixation of this fracture?

Explanation

Operative indications for extra-articular scapular body fractures include marked displacement, specifically medial/lateral translation greater than 20 mm or angular deformity greater than 45 degrees.

Question 44

A 65-year-old man is scheduled for repair of a massive, retracted rotator cuff tear. Which of the following preoperative MRI findings is most strongly associated with a high rate of structural failure following repair?

Explanation

Advanced fatty infiltration (Goutallier stage 3 or 4, where fat is equal to or greater than muscle) is a strong predictor of poor functional outcomes and high re-tear rates following rotator cuff repair.

Question 45

A 28-year-old competitive weightlifter experiences a tearing sensation in his anterior chest wall during a heavy bench press. Examination reveals loss of the anterior axillary fold and weakness in internal rotation. In a typical pectoralis major rupture, which head of the muscle tears most commonly?

Explanation

Pectoralis major ruptures typically occur during eccentric contraction (e.g., bench press). The sternal (sternocostal) head is most frequently injured, often avulsing from its insertion on the proximal humerus.

Question 46

An 18-year-old female gymnast presents with bilateral shoulder pain and a feeling of looseness. Examination reveals generalized ligamentous laxity, a prominent bilateral sulcus sign, and apprehension in multiple positions. She has not had any prior treatment. What is the most appropriate initial management?

Explanation

The patient has multidirectional instability (MDI). The gold standard initial management for MDI is a prolonged, dedicated physical therapy program focusing on rotator cuff and periscapular muscle strengthening.

Question 47

A 25-year-old male cyclist falls onto his shoulder and sustains a midshaft clavicle fracture. Which of the following findings is an absolute indication for acute operative intervention?

Explanation

Absolute indications for surgical fixation of a clavicle fracture include open fractures, neurovascular compromise, and impending open fractures (severe skin tenting with blanching/ischemia).

Question 48

During an arthroscopic remplissage for a patient with an engaging Hill-Sachs lesion, which anatomical structures are tenodesed into the humeral head defect?

Explanation

The remplissage procedure ('to fill' in French) involves suturing the posterior capsule and the infraspinatus tendon into the Hill-Sachs defect to render it extra-articular and prevent engagement.

Question 49

In a patient with cuff tear arthropathy, what radiographic feature characterizes Hamada Stage 3 disease?

Explanation

According to the Hamada classification for cuff tear arthropathy, Stage 3 is characterized by 'acetabularization' of the coracoacromial arch (acromion) and 'femoralization' of the humeral head without true glenohumeral arthritis.

Question 50

How does an Anterior Labroligamentous Periosteal Sleeve Avulsion (ALPSA) lesion differ anatomically from a classic Bankart lesion?

Explanation

Unlike a Bankart lesion where the periosteum tears, an ALPSA lesion involves an intact anterior periosteum. The labro-ligamentous complex strips and displaces medially down the scapular neck, healing in an abnormal position.

Question 51

A 20-year-old male presents to the emergency department following a high-speed motor vehicle collision. He has a posterior sternoclavicular dislocation and complains of progressive shortness of breath and dysphagia. A closed reduction under general anesthesia is attempted but fails. What is the most critical next step in management?

Explanation

Posterior sternoclavicular dislocations can compress the mediastinal structures (trachea, esophagus, great vessels). If closed reduction fails or is contraindicated, urgent open reduction in the operating room with cardiothoracic surgery backup is required.

Question 52

A 22-year-old competitive rugby player presents with recurrent anterior shoulder instability. A 3D CT scan reveals 26% anterior glenoid bone loss. Which of the following is the most appropriate definitive management?

Explanation

In the setting of critical anterior glenoid bone loss (typically >20-25%), a bony augmentation procedure such as the Latarjet is indicated to restore glenoid tracking and prevent recurrent instability. Soft tissue procedures alone have an unacceptably high failure rate in this scenario.

Question 53

A 45-year-old man falls while water skiing and presents with severe shoulder pain and weakness. Physical examination reveals increased passive external rotation compared to the contralateral side, weakness in internal rotation, and a positive belly-press test. Which of the following structures is most likely injured?

Explanation

A positive belly-press test, weakness in internal rotation, and increased passive external rotation are hallmark signs of a subscapularis tendon rupture. This injury is commonly seen following traumatic forced external rotation or extension of the abducted arm.

Question 54

A 68-year-old woman sustains a proximal humerus fracture after a fall from standing height. Which of the following radiographic parameters is the most reliable predictor for the development of avascular necrosis (AVN) of the humeral head?

Explanation

Hertel criteria for predicting ischemia of the humeral head include a disrupted medial hinge and a short calcar segment (<8 mm attached to the articular segment). Disruption of these medial structures heavily compromises the ascending branch of the anterior humeral circumflex artery and intraosseous collateral blood supply.

Question 55

A 35-year-old man presents to the emergency department with severe shoulder pain after experiencing a grand mal seizure. On examination, his arm is locked in internal rotation and he is unable to actively or passively externally rotate the shoulder. An axillary lateral radiograph confirms a posterior glenohumeral dislocation with an anteromedial humeral head defect (reverse Hill-Sachs lesion) involving 35% of the articular surface. Which of the following is the most appropriate surgical treatment?

Explanation

Posterior dislocations are classic after seizures or electrical shocks. For a reverse Hill-Sachs lesion involving 20-40% of the articular surface, transfer of the lesser tuberosity and subscapularis tendon into the defect (Modified McLaughlin procedure) prevents engagement and provides stability.

Question 56

A 26-year-old professional volleyball player complains of vague posterior shoulder pain and progressive weakness. Physical examination demonstrates isolated weakness in external rotation with the arm at the side, but normal abduction strength. There is visible atrophy of the infraspinatus fossa. Where is the most likely location of nerve compression?

Explanation

Isolated atrophy and weakness of the infraspinatus with preserved supraspinatus function (normal abduction) indicates compression of the suprascapular nerve at the spinoglenoid notch. This is often caused by a paralabral cyst associated with a posterior or SLAP labral tear in overhead athletes.

Question 57

A 71-year-old man presents with an inability to actively elevate his right arm above 40 degrees. Passive elevation is full. MRI reveals a massive, retracted tear of the supraspinatus and infraspinatus tendons with Goutallier stage 4 fatty infiltration. His deltoid function is intact. What is the most appropriate surgical intervention?

Explanation

Pseudoparalysis (inability to actively elevate >90 degrees with full passive ROM) in an elderly patient with a massive, irreparable rotator cuff tear (Goutallier stage 3 or 4) is the classic indication for a reverse total shoulder arthroplasty. Anatomic TSA is contraindicated due to the deficient cuff.

Question 58

A 28-year-old cyclist crashes over his handlebars and lands on his shoulder point. Radiographs reveal an acromioclavicular (AC) joint separation with the distal clavicle displaced superiorly by 150% compared to the acromion. Which two ligaments are primarily disrupted in this injury?

Explanation

A Type III or higher AC separation involves complete disruption of both the acromioclavicular ligaments and the coracoclavicular (CC) ligaments. The CC ligaments consist of the medially based conoid ligament and the laterally based trapezoid ligament.

Question 59

A 31-year-old competitive weightlifter felt a 'pop' in his anterior axilla while performing a heavy bench press. Examination shows loss of the normal anterior axillary contour and weakness in internal rotation and adduction. MRI confirms a complete avulsion of the pectoralis major tendon from its humeral insertion. Surgical repair is most likely to restore strength in which of the following motions?

Explanation

The pectoralis major functions primarily to adduct and internally rotate the humerus. Early surgical repair of sternocostal head ruptures at the humeral insertion reliably restores strength in adduction and internal rotation for high-demand athletes.

Question 60

A 42-year-old male is brought to the emergency department after a first-time seizure. He holds his right arm locked in internal rotation. Radiographs reveal a posterior shoulder dislocation with an anteromedial humeral head impaction fracture (reverse Hill-Sachs lesion). A subsequent CT scan shows the defect involves 35% of the articular surface. Which of the following is the most appropriate surgical treatment?

Explanation

Posterior shoulder dislocations following seizures frequently result in a reverse Hill-Sachs lesion. Defects involving 20% to 40% of the articular surface are highly susceptible to engagement and are best treated with a modified McLaughlin procedure (lesser tuberosity transfer) to restore stability.

Question 61

A 72-year-old female presents with chronic severe shoulder pain and an inability to actively elevate her arm above 40 degrees, despite full passive range of motion. Radiographs demonstrate severe glenohumeral osteoarthritis with superior migration of the humeral head articulating with the acromion. Which of the following is the most reliable surgical option?

Explanation

Reverse total shoulder arthroplasty is the gold standard for rotator cuff tear arthropathy with pseudoparalysis. It medializes and distalizes the center of rotation, significantly increasing the deltoid moment arm to compensate for the deficient rotator cuff.

Question 62

A 45-year-old manual laborer presents with deep anterior shoulder pain. Clinical examination reveals a positive O'Brien test and tenderness in the bicipital groove. MRI confirms an isolated type II SLAP tear. After 6 months of failed conservative management, what is the recommended surgical intervention?

Explanation

In patients over the age of 40, especially manual laborers, primary biceps tenodesis yields superior functional outcomes compared to SLAP repair. SLAP repairs in this demographic have an unacceptably high rate of postoperative stiffness and failure.

Question 63

A 22-year-old cyclist sustains a completely displaced midshaft clavicle fracture. Which of the following findings serves as an absolute indication for immediate open reduction and internal fixation?

Explanation

Absolute indications for operative management of clavicle fractures include open fractures, neurovascular compromise, and severe skin tenting causing ischemia (blanching). Shortening and simple skin tenting are considered relative indications.

Question 64

A 68-year-old female sustains a 4-part proximal humerus fracture. According to Hertel's criteria, which of the following radiographic features is the most reliable predictor for the development of humeral head avascular necrosis?

Explanation

Hertel's criteria for high AVN risk include a short calcar segment (metaphyseal extension <8 mm), a disrupted medial hinge, and an anatomic neck fracture line. Conversely, an intact medial hinge is strongly protective against ischemia.

Question 65

A 70-year-old woman presents with severe shoulder pain and an inability to actively elevate her arm past 45 degrees. Radiographs demonstrate superior migration of the humeral head and glenohumeral osteoarthritis. MRI confirms a massive, retracted, and fatty-infiltrated rotator cuff tear. What is the most appropriate surgical treatment?

Explanation

Reverse total shoulder arthroplasty is the treatment of choice for rotator cuff tear arthropathy in older patients with pseudoparalysis. It relies on the deltoid to elevate the arm by medializing and distalizing the center of rotation.

Question 66

A 22-year-old collegiate rugby player has recurrent anterior shoulder instability. CT scan indicates 25% anterior glenoid bone loss. Which of the following is the most appropriate surgical intervention?

Explanation

Glenoid bone loss exceeding 20-25% in a collision athlete is an indication for a bony augmentation procedure like the Latarjet. Soft tissue repairs alone in this setting have an unacceptably high failure rate.

Question 67

A 35-year-old male presents with isolated weakness in external rotation of the shoulder following a severe traction injury. Atrophy of the infraspinatus is noted, but the supraspinatus is clinically and radiographically normal. Where is the most likely site of nerve compression or injury?

Explanation

Compression of the suprascapular nerve at the spinoglenoid notch affects only the infraspinatus muscle. Compression more proximally at the suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 68

A 76-year-old right-hand-dominant woman sustains a highly comminuted 4-part proximal humerus fracture with splitting of the humeral head. The tuberosities are widely displaced. What is the most reliable surgical option to restore active elevation?

Explanation

Reverse total shoulder arthroplasty provides more predictable pain relief and functional restoration in elderly patients with complex 4-part fractures and poor bone quality. It is less reliant on tuberosity healing compared to hemiarthroplasty.

Question 69

A 32-year-old male bodybuilder feels a sudden 'pop' and tearing sensation in his anterior chest wall while performing a heavy bench press. Examination reveals loss of the anterior axillary fold contour and weakness in internal rotation. MRI confirms a complete distal avulsion of the pectoralis major tendon. What is the recommended management?

Explanation

Complete tears of the pectoralis major tendon at its insertion in active individuals are best treated with early surgical repair. This restores strength and normal cosmetic contour of the axillary fold.

Question 70

A 40-year-old man presents with persistent shoulder pain and inability to actively lift his hand off his abdomen (positive belly-press test). MRI demonstrates a complete, retracted subscapularis tear with Goutallier stage 4 fatty infiltration. What is the most appropriate tendon transfer for this patient?

Explanation

Pectoralis major transfer is the standard procedure for an irreparable subscapularis tear to restore anterior stability and internal rotation function. Latissimus dorsi and lower trapezius transfers are typically used for posterosuperior cuff defects.

Question 71

A 65-year-old patient presents with an acute anterior shoulder dislocation after a fall. The joint is successfully reduced. Two weeks later, the patient continues to complain of profound weakness in shoulder abduction and external rotation despite normal radiographs. What is the most likely diagnosis?

Explanation

In patients older than 40 to 60 years, anterior shoulder dislocation is highly associated with an acute rotator cuff tear. Persistent weakness post-reduction in this age group warrants an MRI to evaluate the rotator cuff.

Question 72

A 24-year-old male falls directly onto his shoulder. Examination shows a prominent distal clavicle, and radiographs confirm a Rockwood Type V acromioclavicular (AC) joint separation with 150% superior displacement. What is the recommended management?

Explanation

Type V AC joint injuries, characterized by severe superior displacement and stripping of the deltotrapezial fascia, generally require surgical reconstruction of the coracoclavicular ligaments to restore anatomy and function.

Question 73

Which of the following physical examination findings is most specific for identifying a SLAP (Superior Labrum Anterior to Posterior) tear in a throwing athlete?

Explanation

O'Brien's active compression test is widely used to evaluate for SLAP lesions. Pain elicited with the thumb down that is relieved when the palm is supinated suggests superior labral pathology.

Question 74

A 55-year-old diabetic woman presents with insidious onset of progressive shoulder stiffness and pain over the last 4 months. Passive and active ROM are equally restricted, with external rotation at 0 degrees and forward elevation at 80 degrees. Radiographs are normal. What is the primary pathophysiologic process?

Explanation

Adhesive capsulitis (frozen shoulder) is characterized by fibroblastic proliferation and thickening of the joint capsule, particularly involving the coracohumeral ligament and the rotator interval.

Question 75

A 19-year-old male sustains a posterior sternoclavicular dislocation during a rugby match. He presents to the ER with mild dyspnea and dysphagia. What is the most critical next step in management?

Explanation

Posterior sternoclavicular dislocations can cause life-threatening compression of mediastinal structures. A CT scan with IV contrast (or CT angiogram) is essential to evaluate the great vessels before any reduction attempt.

Question 76

A 30-year-old right-hand-dominant male presents with recurrent anterior shoulder instability. An MRI shows an engaging Hill-Sachs lesion without critical glenoid bone loss. Which of the following procedures specifically addresses the engaging nature of this lesion?

Explanation

The remplissage procedure involves tenodesis of the infraspinatus and posterior capsule into the Hill-Sachs defect. This converts an intra-articular defect into an extra-articular one, preventing it from engaging the anterior glenoid rim.

Question 77

A 45-year-old man falls on his outstretched hand and presents with a displaced, comminuted fracture of the middle third of the clavicle with 2.5 cm of shortening. What is the most significant long-term consequence of nonoperative management of this specific fracture pattern?

Explanation

Clavicle fractures with significant shortening (>2 cm) alter the resting mechanics of the shoulder girdle. This leads to symptomatic nonunion or malunion characterized by decreased shoulder strength, endurance, and altered scapular kinematics.

Question 78

A 22-year-old competitive rugby player presents with recurrent anterior shoulder instability. Advanced imaging reveals 25% anterior glenoid bone loss and an engaging Hill-Sachs lesion. Which of the following surgical procedures is the most appropriate management to minimize the risk of recurrence?

Explanation

For recurrent anterior shoulder instability with critical glenoid bone loss (typically >20%), the Latarjet procedure (coracoid transfer) is the gold standard. It prevents recurrence via a triple effect: a bony block, the sling effect of the conjoined tendon, and capsular repair.

Question 79

A 45-year-old heavy laborer presents with profound external rotation weakness and a massive, irreparable posterosuperior rotator cuff tear. Imaging confirms an intact subscapularis and no evidence of glenohumeral osteoarthritis. Which of the following tendon transfers is most appropriate for this patient?

Explanation

Latissimus dorsi (or lower trapezius) tendon transfers are indicated for young, active patients with irreparable posterosuperior (supraspinatus/infraspinatus) rotator cuff tears and no arthritis. A pectoralis major transfer is indicated for an irreparable subscapularis tear.

Question 80

A 65-year-old woman sustains a highly displaced 4-part proximal humerus fracture. Which of the following radiographic parameters described by Hertel is the most reliable predictor of humeral head ischemia?

Explanation

Hertel described predictors of humeral head ischemia in proximal humerus fractures. The most reliable predictors include a metaphyseal head extension (calcar segment) < 8 mm, disruption of the medial hinge (> 2 mm), and an anatomic neck fracture pattern.

Question 81

During an open repair of a massive, retracted subscapularis tendon tear, extensive medial mobilization of the muscle belly is required. Which neural structure is at greatest risk of iatrogenic injury during this mobilization?

Explanation

The upper and lower subscapular nerves innervate the subscapularis muscle and enter the anterior muscle belly medially. Extensive medial mobilization, especially past the conjoined tendon, places these nerves at significant risk of traction or transection injury.

Question 82

A 75-year-old female presents with a severely comminuted, valgus-impacted 4-part proximal humerus fracture with profound osteopenia. The tuberosities are extensively fragmented. What is the most reliable surgical option to restore active elevation in this patient?

Explanation

In elderly patients with 4-part proximal humerus fractures, poor bone quality, and severely comminuted tuberosities, Reverse Total Shoulder Arthroplasty (RTSA) provides more reliable outcomes and function. Hemiarthroplasty heavily relies on tuberosity healing, which is unpredictable in this population.

Question 83

A 35-year-old male presents with his arm locked in internal rotation following a generalized seizure. A CT scan confirms a posterior shoulder dislocation with an anteromedial humeral head defect (reverse Hill-Sachs lesion) involving 30% of the articular surface. What is the most appropriate management?

Explanation

For locked posterior shoulder dislocations with a reverse Hill-Sachs lesion involving 20-40% of the articular surface, a modified McLaughlin procedure (transfer of the lesser tuberosity/subscapularis into the defect) is indicated to prevent recurrent instability.

Question 84

A 25-year-old cyclist sustains a completely displaced midshaft clavicle fracture. Which of the following findings is considered an absolute indication for operative fixation?

Explanation

Absolute indications for operative fixation of a clavicle fracture include open fractures, neurovascular compromise (e.g., subclavian artery injury), and symptomatic nonunion. Displacement, shortening (> 2 cm), and severe comminution are considered relative indications.

Question 85

Following a standard arthroscopic rotator cuff repair, by which histological mechanism does the tendon primarily heal to the greater tuberosity?

Explanation

Current rotator cuff repair techniques heal primarily by indirect insertion via a fibrovascular scar. They rarely recreate the native direct insertion, which normally consists of four distinct zones: tendon, uncalcified fibrocartilage, calcified fibrocartilage, and bone.

Question 86

A 20-year-old male with recurrent anterior shoulder dislocations is found to have 10% glenoid bone loss and a deep, engaging Hill-Sachs lesion on dynamic arthroscopy. Which of the following is the most appropriate arthroscopic management?

Explanation

An engaging Hill-Sachs lesion in the setting of subcritical glenoid bone loss (<20%) is best managed with an arthroscopic Bankart repair combined with a Remplissage (infraspinatus tenodesis and posterior capsulodesis into the defect). This prevents the lesion from engaging the anterior glenoid rim.

Question 87

A 40-year-old male sustains an isolated extra-articular scapular neck fracture in a motor vehicle collision. Which of the following parameters represents an accepted indication for open reduction and internal fixation?

Explanation

Operative indications for extra-articular scapular neck/body fractures include > 40 degrees of angulation, medial/lateral translation > 1 cm (10 mm), and a glenopolar angle < 22 degrees. These thresholds identify significant displacement that may impair shoulder mechanics if left untreated.

Question 88

A 55-year-old female undergoes open reduction and internal fixation of a proximal humerus fracture with a locking plate. Three months postoperatively, she develops new-onset pain, and radiographs demonstrate intra-articular screw penetration. What is the most common mechanical cause for this complication?

Explanation

The most common cause of secondary screw penetration into the glenohumeral joint after locked plating of a proximal humerus fracture is varus collapse. This typically occurs due to a failure to surgically restore medial column support, such as inadequate placement of inferior calcar screws.

Question 89

A 45-year-old overhead athlete is diagnosed with a symptomatic Type II SLAP tear that has failed conservative management. Compared to an isolated SLAP repair, performing a primary biceps tenodesis in this age group is typically associated with:

Explanation

In patients older than 40 years with Type II SLAP tears, primary biceps tenodesis has demonstrated lower complication rates, lower revision rates, and improved clinical outcomes compared to SLAP repair. SLAP repairs in this demographic are frequently complicated by postoperative stiffness.

Question 90

A 30-year-old elite volleyball player presents with vague posterior shoulder pain. MRI reveals a large paralabral cyst in the spinoglenoid notch. Which of the following physical examination findings is most specific to this anatomic level of nerve compression?

Explanation

A paralabral cyst in the spinoglenoid notch compresses the suprascapular nerve after it has already innervated the supraspinatus muscle. This leads to isolated denervation of the infraspinatus, presenting clinically as isolated external rotation weakness with preserved abduction strength.

Question 91

A 25-year-old male falls directly onto his acromion. Radiographs reveal 150% superior displacement of the distal clavicle relative to the acromion, and an axillary view shows the clavicle displaced posteriorly into the trapezius fascia. What is the Rockwood classification of this acromioclavicular joint injury?

Explanation

A Rockwood Type IV AC joint injury is characterized by posterior displacement of the distal clavicle into or through the trapezius fascia. Type V injuries feature >100-300% superior displacement but without the hallmark posterior fascial displacement seen in Type IV.

Question 92

An 18-year-old football player is tackled directly onto his lateral shoulder and presents with severe pain, shortness of breath, and dysphagia. Examination suggests a posterior sternoclavicular joint dislocation. After securing the airway, what is the gold-standard imaging modality to evaluate this injury?

Explanation

Posterior sternoclavicular joint dislocations are orthopedic emergencies due to the proximity of vital mediastinal structures (trachea, esophagus, great vessels). A contrast-enhanced CT scan is the gold standard to accurately evaluate the joint and simultaneously assess for vascular injury.

Question 93

A 68-year-old male who underwent an anatomic total shoulder arthroplasty 5 years ago presents with new-onset shoulder pain and clicking. Radiographs reveal superior migration of the humeral head and an asymmetric radiolucent line around the glenoid component, suggestive of the 'rocking horse' phenomenon. What is the primary etiology of this finding?

Explanation

The 'rocking horse' phenomenon in anatomic total shoulder arthroplasty refers to early glenoid component loosening caused by eccentric loading. This most commonly results from late failure of the rotator cuff, causing superior migration of the humeral head and subsequent asymmetric superior loading on the glenoid.

100 High-Yield Orthopedic MCQs: Shoulder & Elbow | Mock Exam 251

ABOS Shoulder MCQs (Set 2): Rotator Cuff, Instability & Fractures | Board Review

Key Takeaway

ABOS Shoulder MCQs (Set 2): Rotator Cuff, Instability & Fractures | Board Review

Chapter Index