100 Orthopedic MCQs: ABOS & OITE Mock Exam Set 311

Question 1

Figure 53a shows the AP radiograph of a 70-year-old patient who is scheduled to undergo unicompartmental knee arthroplasty. Figure 53b shows the immediate postoperative radiograph, and the radiograph shown in Figure 53c, obtained 6 months after surgery, shows a medial tibial plateau fracture. The etiology of the fracture is best related to

Explanation

While all of the above may contribute to the etiology of a tibial plateau fracture following unicompartmental knee arthroplasty, the recent literature has clearly noted that pin placement for fixation of tibial resection guides is the most critical factor associated with a tibial plateau fracture following unicompartmental knee arthroplasty. Vince and Cyran suggest that fractures associated with unicompartmental knee arthroplasty might be avoidable by limiting the number and paying attention to the location of the pin holes that are created to secure the tibial resection guides. Brumby and associates suggest avoiding multiple guide pin holes in the proximal tibia for unicompartmental knee arthroplasty. They currently recommend the use of one centrally placed pin and an ankle clamp to stabilize the resection guide. Yang and associates note that a medial tibial plateau fracture in association with minimally invasive unicompartmental knee arthroplasty can be eliminated by avoiding fixation pins close to the medial tibial cortex. Brumby SA, Carrington R, Zayontz S, et al: Tibial plateau stress fracture: A complication of unicompartmental knee arthroplasty using 4 guide pinholes. J Arthroplasty 2003;18:809-812. Yang KY, Yeo SJ, Lo NN: Stress fracture of the medial tibial plateau after minimally invasive unicompartmental knee arthroplasty: A report of 2 cases. J Arthroplasty 2003;18:801-803.

References:

Vince KG, Cyran LT: Unicompartmental knee arthroplasty: New indications, more complications? J Arthroplasty 2004;19:9-16.

Question 2

What is the most prevalent adverse event associated with allogeneic blood transfusion?

Hip & Knee Reconstruction 2007 Practice Questions: Set 1 (Solved) - Figure 29

Explanation

Clerical error leading to acute hemolysis and even death occurs in 1:12,000 to 1:50,000 transfusions. Bacterial contamination leading to sepsis/shock occurs in 1:1 million transfusions. HIV transmission is approximately 1:500,000 transfusions and hepatitis C is 1:103,000 transfusions. Anaphylactic reactions occur in 1:150,000 transfusions. Aubuchon JP, Birkmeyer JD, Busch MP: Safety of the blood supply in the United States: Opportunities and controversies. Ann Intern Med 1997;127:904-909.

References:

Popovsky MA, Whitaker B, Arnold NL: Severe outcomes of allogeneic and autologous blood donation: Frequency and characterization. Transfusion 1995;35:734-737.

Question 3

The MRI scan shown in Figure 24 reveals a right-sided herniated nucleus pulposus at L4-5 in a patient with pain in the right leg. Administration of a caudal epidural steroid injection provides immediate relief. Over the next week he notes generalized weakness of the lower extremities and has one episode of urinary incontinence. What is the next most appropriate step in management?

Spine Surgery 2000 Practice Questions: Set 3 (Solved) - Figure 11

Explanation

Whenever a patient's condition changes following a test or a procedure, the physician must determine the cause. A steroid flare reaction will not cause incontinence or weakness of the lower extremities. An L4-5 diskectomy may alleviate the problem if the right-sided L4-5 disk herniation is the etiology of the symptoms. However, it is unlikely that a right-sided disk herniation alone will cause a cauda equina syndrome. Possible etiologies include a further extrusion of a disk fragment at L4-5 that now obliterates the spinal canal, a disk herniation at another level, or an epidural abscess following injection of corticosteroids through a caudal approach. In the presence of a possible infection, myelography should not be performed from a lumbar puncture. The fastest and least invasive way to make an appropriate diagnosis is to obtain an MRI of the lumbar spine. In this patient, the MRI revealed an epidural abscess that was compressing the cauda equina. Because of the large dose of steroids that were injected, the patient did not manifest symptoms such as fevers and chills until late in the course. Knight JW, Cordingley JJ, Palazzo MG: Epidural abscess following epidural steroid and local anaesthetic injection. Anaesthesia 1997;52:576-578.

References:

Abram SE, O'Connor TC: Complications associated with epidural steroid injections. Reg Anesth 1996;21:149-162.

Question 4

What is the most common organism found following a nail puncture wound through tennis shoes in a host without immunocompromise?

Explanation

The association of a nail puncture wound with a gram-negative infection (Pseudomonas aeruginosa) has been attributed to the local environmental factors in shoes. Osteomyelitis is rare, occurring only in about 1% of patients. Tetanus prophylaxis should be given if it is not up to date. While the remaining organisms listed are periodically involved, they are more common in patients who are immunocompromised or who have diabetes mellitus. Therefore, obtaining a culture of the infected wound is appropriate in such individuals because of the multifactorial nature of the infection. Green NE, Bruno J III: Pseudomonas infections of the foot after puncture wounds. South Med J 1980;73:146-149.

References:

Riegler HF, Routson GW: Complications of deep puncture wounds of the foot. J Trauma 1979;19:18-22.

Question 5

A 29-year-old quarterback falls onto his dominant shoulder and sustains the injury shown in Figures 14a and 14b. Management should consist of

Explanation

Type V acromioclavicular dislocations are characterized by elevation of the clavicle of 100% to 300% and involve extensive soft-tissue stripping. The treatment of choice is surgical reduction of the acromioclavicular joint and some type of stabilization. Treatment of type III injuries is controversial. Lemos MJ: The evaluation and treatment of the injured acromioclavicular joint in athletes. Am J Sports Med 1998;26:137-144.

References:

Rockwood CA Jr, Green DP, Bucholz RW, et al: Fractures in Adults, ed 5. Philadelphia, PA, Lippincott-Raven, 2001, pp 1209-1240.

Question 6

Examination of a 10-year-old girl with a hypoplastic breast and atrophic pectoralis major may also reveal which of the following findings?

Explanation

Poland's syndrome has four main features: 1) short digits as the result of absence or shortening of the middle phalanx; 2) syndactyly of the short digits usually consisting of a simple, complete type; 3) hypoplasia of the hand and forearm; and 4) absence of the sternocostal head of the pectoralis major on the same side. Wilson MR, Louis DS, Stevenson TR: Poland's syndrome: Variable expression and associated anomalies. J Hand Surg 1988;13:880-882.

References:

Poland A: Deficiency of the pectoralis muscle. Guys Hosp Rep 1841;6:191.

Question 7

An 18-year-old man has acute respiratory distress after sustaining injuries in a motorcycle accident. He has a blood pressure of 80/60 mm Hg and a pulse rate of 110/min. Examination reveals chest tympany to percussion, distended neck veins, and deviation of the trachea away from his right hemithorax where the breath sounds are diminished. Heart sounds are regular and normal on auscultation. Initial management should consist of

Trauma Board Review 2000: High-Yield MCQs (Set 2) - Figure 20

Explanation

Tension pneumothorax occurs when air trapped in the pleural space between the lung and chest wall achieves sufficient pressure to compress the lungs and shift the mediastinum. Urgent needle decompression of the pleural space air followed by definitive chest tube placement is the treatment of choice.

References:

Mattox KL, Feliciano DV, Moore EE (eds): Management of Shock, ed 4. New York, NY, McGraw Hill, 2000, p 215.

Question 8

In the anterior approach (Smith-Petersen) to the hip, dissection is carried out between muscles innervated by the

Anatomy Board Review 2002: High-Yield MCQs (Set 2) - Figure 21

Explanation

In the Smith-Petersen approach to the hip, dissection is carried out between the tensor fascia lata laterally (supplied by the superior gluteal nerve) and the sartorius and rectus femoris medially (both supplied by the femoral nerve). Crenshaw AH Jr: Surgical techniques and approaches, in Canale ST (ed): Campbell's Operative Orthopaedics, ed 9. St Louis, MO, Mosby-Year Book, 1998, vol 1, pp 82-85.

References:

Williams PL, Warwick R, Dyson M, Bannister LH: Myology, in Gray's Anatomy, ed 37. Edinburgh, Scotland, Churchill Livingstone, 1989, pp 638-639.

Question 9

A 55-year-old woman fell and sustained an elbow dislocation with a coronoid fracture and a radial head fracture. The elbow is reduced and splinted. What is the most common early complication?

Trauma Board Review 2006: High-Yield MCQs (Set 2) - Figure 23

Explanation

The patient has a dislocation of the elbow with displaced coronoid process and radial head fractures. The elbow is extremely unstable after this injury, and recurrent dislocation in a splint is the most common early complication. Skeletal stabilization of the fractures is required to restore stability of the joint. Characteristics of the fractures will determine the techniques required to restore stability. Ring D, Jupiter JB, Zilberfarb J: Posterior dislocation of the elbow with fractures of the radial head and coronoid. J Bone Joint Surg Am 2002;84:547-551.

References:

Ring D, Jupiter JB: Fracture-dislocation of the elbow. J Bone Joint Surg Am 1998;80:566-580.

Question 10

What is the most common secondary malignancy arising in pagetic bone?

Basic Science 2005 Practice Questions: Set 1 (Solved) - Figure 45

Explanation

The incidence of malignant transformation or the formation of a secondary malignancy in pagetic bone is estimated to be less than 1%. Osteosarcoma is the most common secondary malignancy, followed by fibrosarcoma and chondrosarcoma. Ewing's sarcoma arising in pagetic bone has not been reported. Grimer RJ, Carter SR, Tillman RM, et al: Osteosarcoma of the pelvis. J Bone Joint Surg Br 1999;81:796-802.

References:

Harrington KD: Surgical management of neoplastic complications of Paget's disease. J Bone Miner Res 1999;14:45-48.

Question 11

Which of the following prognostic indicators is associated with the least favorable outcome for patients newly diagnosed with osteosarcoma?

Explanation

Distant bone metastasis is associated with an extremely poor prognosis for patients with osteosarcoma (5-year survival rate of less than 10%). Most osteosarcomas are high grade and extracompartmental, and approximately half are greater than 8 cm at presentation. The 5-year survival rate for these patients is approximately 70%. Patients with a solitary pulmonary metastasis have a prognosis worse than patients without detectable metastases but not as bad as those with bone metastases. Bielack SS, Kempf-Bielack B, Delling G, et al: Prognostic factors in high-grade osteosarcoma of the extremities or trunk: An analysis of 1,702 patients treated on neoadjuvant cooperative osteosarcoma study group protocols. J Clin Oncol 2002;20:776-790. Heck RK, Stacy GS, Flaherty MJ, et al: A comparison study of staging systems for bone sarcomas. Clin Orthop Relat Res 2003;415:64-71.

References:

Kager L, Zoubeck A, Potschger U, et al: Primary metastatic osteosarcoma: Presentation and outcome of patients treated on neoadjuvant Cooperative Osteosarcoma Study Group protocols. J Clin Oncol 2003;21:2011-2018.

Question 12

A 40-year-old woman underwent an arthroscopic acromioplasty and mini-open rotator cuff repair 4 weeks ago. At follow-up examination, the incision is painful, erythematous, and draining fluid. The patient is febrile and has an elevated WBC count. What infectious organism should be under high suspicion of causing this outcome?

Upper Extremity 2008 Practice Questions: Set 1 (Solved) - Figure 6

Explanation

Proprionobacter acnes has been a leading cause of indolent shoulder infections. During shoulder arthroscopy, the arthroscopic fluid may actually dilute the shoulder preparation and lead to a higher rate of infection during subsequent mini-open rotator cuff repair surgery. The remaining bacteria listed are rarely associated with shoulder infections after arthroscopy. Herrera MF, Bauer G, Reynolds F, et al: Infection after mini-open rotator cuff repair. J Shoulder Elbow Surg 2002;11:605-608.

References:

Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 551-557.

Question 13

A 70-year-old former baseball catcher reports long-standing pain in the ring and little fingers. A gradient-echo MRI scan is shown in Figure 26. What is the most likely diagnosis?

Anatomy Board Review 2005: High-Yield MCQs (Set 2) - Figure 27

Explanation

The gradient-echo MRI scan highlights the ulnar and radial arteries, as indicated by the arrow. This technique suppresses the signal of the surrounding fat and causes the stationary surrounding tissues to become intermediate in signal intensity. The flowing blood is then easily identified with a bright signal because it does not absorb the radiofrequency pulse. Based on the findings, the diagnosis is an ulnar artery aneurysm, most likely caused by years of repetitive trauma as the result of catching baseballs. Neurolemmoma and giant cell tumor of the tendon sheath would be intermediately enhanced on this image sequence, and the continuity with the ulnar artery, demonstrated here, would not be expected. Lipomas are not enhanced using the gradient-echo technique. The chronic nature of the patient's symptoms is not indicative of a hematoma, and the hematoma would be dark on this imaging sequence since it is stationary tissue. Koman LA, Ruch DS, Patterson Smith B, et al: Vascular disorders, in Green DP, Hotchkiss RN, Pederson WC (eds): Green's Operative Hand Surgery, ed 4. New York, NY, Churchill Livingstone, 1999, vol 2, pp 2254-2302.

References:

Holder LE, Merine DS, Yang A: Nuclear medicine, contrast angiography, and magnetic resonance imaging for evaluating vascular problems in the Hand: Vasospastic disorders. Hand Clin 1993;9:95-113.

Question 14

A 19-year-old man sustains a low-velocity gunshot wound to the forearm. What factor most strongly correlates with the development of compartment syndrome after this injury?

Explanation

In a multivariate analysis, the strongest factor for the development of compartment syndrome is fracture of the proximal third of the forearm. However, compartment syndrome can still occur without a fracture. Therefore, these patients should be followed with a high level of suspicion for the development of compartment syndrome. Moed BR, Fakhouri AJ: Compartment syndrome after low-velocity gunshot wounds to the forearm. J Orthop Trauma 1991;5:134-137.

References:

Hahn M, Strauss E, Yang EC: Gunshot wounds to the forearm. Orthop Clin North Am 1995;26:85-93.

Question 15

A 32-year-old woman has left second toe dactylitis (sausage toe). Radiographs show a "pencil in cup" distal interphalangeal joint deformity. Examination reveals that subtalar motion is markedly reduced. What is the most likely diagnosis?

Foot & Ankle 2006 Practice Questions: Set 1 (Solved) - Figure 35

Explanation

The patient's clinical picture is considered the classic presentation for psoriatic arthritis. The other answers are not applicable for the constellation of findings. Jahss MH: Disorders of the Foot and Ankle, ed 2. Philadelphia, PA, WB Saunders, 1991, pp 1691-1693.

References:

Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 172-173.

Question 16

When performing surgery on a patient with insertional Achilles tendinitis and a Haglund's deformity, how much of the Achilles tendon insertion can be safely detached without having to consider reattachment with bone anchors?

Explanation

The Achilles tendon insertion encompasses a broad area on the posterior area of the calcaneus. A biomechanical study has shown that up to 50% of the Achilles tendon insertion point can be detached before the strength of the attachment point starts to weaken. It is recommended that if more than this amount is detached to remove the posterior superior calcaneal prominence, consideration should be given to either securing the tendon to the bone with suture anchors or performing a tendon transfer. Kolodziej P, Glisson RR, Nunley JA: Risk of avulsion of the Achilles tendon after partial excision for treatment of insertional tendinitis and Haglund's deformity: A biomechanical study. Foot Ankle Int 1999;20:433-437.

Scientific References

:

Sammarco GJ, Taylor AL: Operative management of Haglund's deformity in the nonathlete: A retrospective study. Foot Ankle Int 1998;19:724-729.

Question 17

A patient with a cobalt-chromium alloy (Co-Cr) femoral stem has a periprosthetic fracture that is to be fixed with a cable-plate device. The surgeon should make sure that the plate, screws, and cable, respectively, are made of

Explanation

Contact between metals in a biologic environment leads to galvanic corrosion. Reduction potentials of Co-Cr and stainless steel produce the worst combination of metals in commonly used implants. Because the fixation implants are not intended to contact the existing implant, it is not as great a consideration as the plate and the screws and cables that will directly contact each other. Miller MD (ed): Review of Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 119-144.

References:

Wright TM, Maher SA: Biomaterials, in Einhorn TA, O'Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 18

An active 47-year-old woman with rheumatoid arthritis reports forefoot pain and deformity and has difficulty with shoe wear. Examination reveals hallux valgus and claw toes. A radiograph is shown in Figure 10. What is the most appropriate surgical treatment?

Foot & Ankle 2006 Practice Questions: Set 1 (Solved) - Figure 33

Explanation

Rheumatoid arthritis commonly affects the metatarsophalangeal joints, which become destabilized with time resulting in hallux valgus and dislocated lesser claw toes. The result is metatarsalgia as the dislocated claw toes "pull" the fat pad distally. Severe hallux valgus reduces first ray load, which compounds the metatarsalgia because the load is transferred to the lesser metatarsal heads. First metatarsophalangeal arthrodesis restores weight bearing medially and corrects the painful bunion. Metatarsal head resection slackens the toe tendons to allow correction of the claw toes by whatever means necessary and decreases plantar load over the forefoot. Rheumatoid arthritis in the first metatarsophalangeal joint will continue to progress if osteotomies or a Lapidus procedure are performed. Keller resection arthroplasty increases transfer metatarsalgia and reduces push-off power during gait. Flexor-to-extensor tendon transfer of the lesser toes does not address the metatarsalgia and does not correct the dislocation of the metatarsophalangeal joint. Coughlin MJ: Arthritides, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, p 572.

References:

Abdo RV, Iorio LJ: Rheumatoid arthritis of the foot and ankle. J Am Acad Orthop Surg 1994;2:326-332.

Question 19

Figures 61a and 61b show the CT and MRI scans of a 40-year-old man who has hip pain. He undergoes total hip arthroplasty and curettage and cementation of the lesion as shown in Figure 61c. Histopathologic photomicrographs of the curettage specimen are shown in Figures 61d and 61e. What is the best course of treatment?

Explanation

The definitive surgery would be removal of the entire resection bed, and in this case of dedifferentiated chondrosarcoma, a hemipelvectomy was performed. The MRI and CT scans show an aggressive cartilage lesion. The histology, representative of a dedifferentiated chondrosarcoma, shows a bimorphic low-grade cartilage lesion with high-grade spindle cell sarcoma. The cartilage lesion is usually an enchondroma or low-grade chondrosarcoma. The dedifferentiated portion is typically a malignant fibrous histocytoma, osteosarcoma, or fibrosarcoma. Weber KL, Pring ME, Sim FH: Treatment and outcome of recurrent pelvic chondrosarcoma. Clin Orthop Relat Res 2002;397:19-28.

References:

Pring ME, Weber KL, Unni KK, et al: Chondrosarcoma of the pelvis: A review of sixty-four cases. J Bone Joint Surg Am 2001;83:1630-1642

Question 20

Figures 48a and 48b show the elbow radiographs of a 5-year-old boy who fell from a tree after dinner. Examination reveals that he is unable to extend his wrist. Management should consist of immediate

Explanation

In the absence of vascular compromise, there has been no proven value to proceeding immediately to surgery, especially when the patient has a full stomach and runs a significant risk of perioperative aspiration. It would be more prudent to wait until the next morning with a surgical plan of closed reduction and pinning. Open reduction should be reserved for the unusual case of where closed treatment has not been successful. The implication that there may be a radial nerve injury associated with this fracture does not alter the treatment plan, and with a high level of certainty would be expected to resolve. Attempting closed reduction in the emergency department creates the opportunity for uncertain results and is not tolerated well by most patients. Skeletal traction, with its associated lengthy hospitalization and the technical difficulties associated with both the traction and radiographic evaluations, has fallen into disfavor for typical clinical situations. Iyengar SR, Hoffinger SA, Townsend DR: Early versus delayed reduction and pinning of type III displaced supracondylar fractures of the humerus in children: A comparative study. J Orthop Trauma 1999;13:51-55.

References:

Leet AI, Frisancho J, Ebramzadeh E: Delayed treatment of type 3 supracondylar humerus fractures in children. J Pediatr Orthop 2002;22:203-207.

Question 21

A patient who underwent a high tibial osteotomy (HTO) is now scheduled to undergo total knee arthroplasty (TKA). When compared with a patient undergoing primary TKA without a prior HTO, the patient should be advised to expect a higher incidence of

Explanation

Conversion TKA following a previous HTO can be successful; however, it is associated with poorer clinical results when compared with other primary TKAs. There is an increased likelihood of poor range of motion that is partially affected by patella infera created from the osteotomy. Patella infera also results in difficulty with surgical exposure. There has been no reported increase in the rate of infection, fracture, or loosening.

Scientific References

:

Mont MA, Alexander N, Krackow KA, Hungerford DS: Total knee arthroplasty after failed high tibial osteotomy. Orthop Clin North Am 1994;25:515-525.

Question 22

A patient has right shoulder pain. Figure 1a shows a gadolinium-enhanced transverse MRI scan at the level of the coracoid. Figure 1b shows an arthroscopic view of the anterior structures from a posterior portal. These images reveal which of the following findings?

Explanation

The area shown in the arthroscopic view and MRI scan is referred to as a Buford complex and represents a normal labral variant. It consists of a thickened, cord-like middle glenohumeral ligament, a superior labral attachment of the middle glenohumeral ligament just anterior to the biceps tendon, and absence of the anterosuperior labrum. This combination of findings can be confusing and may simulate labral pathology. Mistaken repair of the lesion back to the glenoid rim can result in significant loss of external rotation. A Bankart lesion would be located at the inferior anterior glenoid rim. The subscapularis is seen anterior to the labrum. Normal variations that occur in the anterosuperior labrum can simulate pathology. Gusmer PB, Potter HG, Schatz JA, et al: Labral injuries: Accuracy of detection with unenhanced MR imaging of the shoulder. Radiology 1996;200:519-524. Griffin LY (ed): Orthopaedic Knowledge Update: Sports Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 47-63.

Scientific References

:

Williams MM, Snyder SJ, Buford D Jr: The Buford complex: The "cord-like" middle glenohumeral ligament and absent anterosuperior labrum complex. A normal anatomic capsulolabral variant. Arthroscopy 1994;10:241-247.

Question 23

During shoulder motion with the elbow controlled in a brace, electromyographic studies of the supraspinatus show significant activity with all range-of-motion testing. Concurrent electromyographic studies of the long head of the biceps will most likely show

Upper Extremity Board Review 2005: High-Yield MCQs (Set 2) - Figure 13

Explanation

During electromyographic studies, the long head of the biceps has been shown to have little activity throughout a wide range of shoulder motion as long as the elbow is immobilized. The supraspinatus is active throughout the range of shoulder motion. Rotator cuff tears do not influence biceps activity as long as the elbow is controlled. Yamaguchi K, Riew KD, Galutz LM, et al: Biceps activity during shoulder motion: An electromyographic analysis. Clin Orthop 1997;336:122-129.

References:

Levy AS, Kelly BT, Lintner SA, et al: Function of the long head of the biceps at the shoulder: Electromyographic analysis. J Shoulder Elbow Surg 2001;10:250-255.

Question 24

A 56-year-old man underwent right total shoulder arthroplasty 2 months ago. Recently while reaching with his shoulder in a flexed and adducted position, he noted shoulder pain and afterwards he could not externally rotate his arm. An axillary radiograph is shown in Figure 30. What is the most likely cause of this problem?

Upper Extremity 2005 Practice Questions: Set 3 (Solved) - Figure 15

Explanation

Anteversion of the humeral component may result in anterior instability of the component. Posterior instability after total shoulder arthroplasty is usually the result of some combination of the following factors: untreated anterior soft-tissue contractures, excessive posterior capsular laxity, and excessive retroversion of the humeral and/or glenoid components. Cofield RH, Edgerton BC: Total shoulder arthroplasty: Complications and revision surgery. Instr Course Lect 1990;39:449-462.

References:

Wirth MA, Rockwood CA Jr: Complications of total shoulder replacement arthroplasty. J Bone Joint Surg Am 1996;78:603-616.

Question 25

A 16-year-old high school football player has diffuse pain with attempted digital flexion after injuring the ring finger of the dominant hand 1 week ago. Examination reveals that he is unable to flex the distal interphalangeal joint. Management should consist of

Explanation

The patient has an avulsion of the flexor digitorum profundus. Treatment should include surgical exploration and tendon reinsertion. This is not an avulsion of the flexor digitorum superficialis because the patient's deficiency is the inability to flex the distal interphalangeal joint, not the proximal interphalangeal joint. Surgical release of the anterior interosseous nerve is not indicated because the flexor digitorum profundus of the ring finger is innervated by the ulnar nerve. A median nerve contusion causes wrist pain and/or numbness and tingling in the median nerve distribution. Strickland JW: Flexor tendons: Acute injuries, in Green DP, Hotchkiss RN, Pederson WC (eds): Green's Operative Hand Surgery, ed 4. Philadelphia, PA, 1999, pp 1851-1897.

References:

Leddy JP: Avulsions of the flexor digitorum profundus. Hand Clin 1985;1:77-83.

Question 26

A 74-year-old man reports progressive left hip pain with weight-bearing activities. A radiograph is shown in Figure 30. What is the most likely underlying diagnosis?

Anatomy Board Review 2008: High-Yield MCQs (Set 2) - Figure 39

Explanation

The radiograph shows enlargement of the bone, coarse trabeculation, a blastic appearance, and thickening of the cortex, revealing the classic appearance of Paget's disease in the sclerotic phase, the most common presentation. While lymphoma may present as a blastic lesion, it will not have the same enlargement, coarse trabeculation of bone, and the significant sclerosis seen here. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 211-215.

References:

Resnick D (ed): Diagnosis of Bone and Joint Disorders. Philadelphia, PA, WB Saunders, 2002, pp 1947-2000.

Question 27

The cavovarus deformity associated with Charcot-Marie-Tooth (CMT) disease is caused by which of the following?

Explanation

The most common inherited neuromuscular disease seen by orthopaedic surgeons is CMT, which is an inherited autosomal-dominant disease. It is more commonly seen in men due to the nature of the inheritance. Identification of cavus deformity in the foot of a child should arouse suspicion. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 135-143. Charcot-Marie-Tooth Disease (CMT) Penn State Hershey Medical Center. www.hmc.psu.edu/healthinfo/c/cmt.htm

Question 28

Figures 21a through 21c show the MRI scans of a 21-year-old football player who sustained a valgus knee injury while changing direction. Examination reveals swelling and tenderness along the medial aspect of the knee. There is a positive Lachman test, 3+ valgus laxity at 30 degrees, and 1+ valgus laxity at 0 degrees extension. The anterior drawer test is increased with the tibia in external rotation. The increase in the anterior drawer test with the tibia in external rotation is most likely the result of

Explanation

The injury mechanism involves a valgus load applied to the knee with the foot in external rotation. The primary stabilizer to valgus laxity is the medial collateral ligament. The secondary restraints to valgus rotation are the cruciate ligaments. Examination indicates disruption of the medial collateral and anterior cruciate ligaments. Valgus opening in extension should also arouse suspicion for an injury to the posterior cruciate ligament; however, in this patient, the valgus opening in extension is mild. The slight opening in extension and the increased anterior drawer, especially with external rotation, indicates disruption of the posteromedial capsule and posterior oblique ligament. Figure 21a shows complete disruption of the superficial and deep medial collateral ligaments involving the meniscofemoral ligament. Figure 21b shows a more posterior coronal section with a torn posterior oblique ligament. Figure 21c shows disruption of the anterior cruciate ligament, while the posterior cruciate ligament at the tibial insertion appears with a homogenous normal signal. Warren LA, Marshall JL, Girgis F: The prime static stabilizer of the medial side of the knee. J Bone Joint Surg Am 1974;56:665-674.

References:

Indelicato PA: Injury to the medial capsuloligamentous complex of the knee, in Feagin J (ed): The Crucial Ligaments, ed 2. 1994, pp 351-360.

Question 29

A 43-year-old woman has had pain in the left hip for the past 2 months. A radiograph, CT scan, MRI scan, and biopsy specimens are shown in Figures 16a through 16e. What is the most likely diagnosis?

Explanation

The imaging studies are consistent with a chondrosarcoma. The radiograph shows a radiolucent lesion in the pelvis, and there are stippled calcifications on the CT scan. The histology shows a low-grade cellular hyaline cartilage neoplasm with stellate, occasionally binucleated chondrocytes. Enchondroma has a more benign histologic appearance.

References:

Mirra JM, Gold R, Downs J, Eckardt JJ: A new histologic approach to the differentiation of enchondroma and chondrosarcoma of the bones: A clinicopathologic analysis of 51 cases. Clin Orthop 1985;201:214-237.

Question 30

Figure 23 shows the radiograph of a 55-year-old man who underwent a total hip arthroplasty 5 years ago. Management should now consist of

Hip 2001 Practice Questions: Set 3 (Solved) - Figure 3

Explanation

Because the radiograph shows that the femoral stem is loose within the femoral canal and there is a fracture in the distal cement mantle, the stem should be revised. The Ogden-type plate and the allograft bone plates will reconstruct the femur but will not restore stability to the stem. Similarly, traction may allow the femur to heal but will not restore stability to the femoral stem within the femur. Resection arthroplasty is considered a salvage option following failure of the other procedures. Lewallen DG, Berry DJ: Periprosthetic fracture of the femur after total hip arthroplasty: Treatment and results to date, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 243-249.

References:

Bethea JS, DeAndrade JR, Fleming LL, Lindenbaum SD, Welch RB: Proximal femoral fractures following total hip arthroplasty. Clin Orthop 1982;170:95-106.

Question 31

What is the most common cause of mechanical failure of an orthopaedic biomaterial during clinical use?

Explanation

In most orthopaedic applications, the materials are strong enough to withstand a single cycle of loading in vivo. However, these loads may be large enough to initiate a small crack in the implant that can grow slowly over thousands or millions of cycles, eventually leading to gross failure. Such fatigue failure has occurred with virtually every type of implant, including stainless steel fracture plates and screws, bone cement in joint arthroplasty, and polyethylene inserts in total knee arthroplasty. Lewis G: Fatigue testing and performance of acrylic bone-cement materials: State-of-the-art review. J Biomed Mater Res Br 2003;66:457-486. Stolk J, Verdonschot N, Huiskes R: Stair climbing is more detrimental to the cement in hip replacement than walking. Clin Orthop 2002;405:294-305.

References:

Wright TM, Maher SA: Biomaterials, in Einhorn TA, O'Keefe RJ, Buckwalter JA (eds): Orthopaedic Basic Science: Foundations of Clinical Practice, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, in press.

Question 32

A 56-year-old woman has a painful mass on the bottom of her left foot, and orthotic management has failed to provide relief. Examination reveals that the mass is contiguous with the plantar fascia. An MRI scan shows a homogenous nodule within the plantar fascia. Resection of the tumor is shown in the clinical photograph in Figure 39. What type of cell is most likely responsible for the formation of this tumor?

Foot & Ankle Board Review 2006: High-Yield MCQs (Set 4) - Figure 10

Explanation

The history, examination, and surgical findings are most consistent with plantar fibromatosis. Plantar fibromatosis is a benign tumor of the plantar fascia that consists chiefly of fibromyoblasts. These cells produce excessive collagen and are similar to the cells found in the palmar fascia of patients with Dupuytren's contracture of the hand. The myocyte, synovial cell, and osteocyte all produce their respective individual tissue types but do not contribute to the formation of a plantar fibromatosis. The T-cell is an important immunologic cell that is most affected in patients with HIV.

References:

Sammarco GJ, Mangone PG: Classification and treatment of plantar fibromatosis. Foot Ankle Int 2000;21:563-569.

Question 33

Figure 50 shows the cross table lateral radiograph of a 31-year-old paratrooper who has recalcitrant groin pain. The pain is worse after activities such as standing or sitting (driving). Examination reveals that pain can be reproduced by internal rotation of the leg with the hip and knee in 90 degrees of flexion. Extensive nonsurgical managment has failed to provide relief. What is the treatment of choice?

Hip & Knee Reconstruction Board Review 2007: High-Yield MCQs (Set 4) - Figure 7

Explanation

The radiograph reveals the classic "bump" that is seen in patients with femoroacetabular impingement (FAI). Ganz and associates described two types of FAI. This patient has cam impingement, which describes a nonspherical femoral head being forced into the acetabulum during hip motion and resulting in labral and chondral injury. Hip arthroscopy and labral debridement is unlikely to control the symptoms because the underlying anatomic abnormality is often difficult to address with arthroscopy. The treatment involves surgical dislocation of the hip with preservation of the blood supply to the femoral head, removal of the asphericity on the femoral side (femoral osteoplasty), and removal of the acetabular rim (acetabular osteoplasty) if the latter is found to contribute to impingement. Ganz R, Gill TJ, Gautier E, et al: Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br 2001;83:1119-1124. Ganz R, Parvizi J, Beck M, et al: Femoroacetabular impingement: A cause for early osteoarthritis of the hip. Clin Orthop 2003;417:112-120.

References:

Beck M, Leunig M, Parvizi J, et al: Anterior femoroacetabular impingement: Part II. Midterm results of surgical treatment. Clin Orthop 2004;418:67-73.

Question 34

A 72-year-old woman who was doing well after undergoing total shoulder arthroplasty for arthritis 4 months ago is suddenly unable to elevate her arm. Examination reveals 70 degrees of external rotation compared with 45 degrees on the uninvolved side, and she is unable to lift her hand off her lower back. Radiographs are shown in Figures 43a through 43c. Treatment should consist of

Explanation

Results of treatment of subscapularis rupture are best when immediate repair is performed. When the cause of the anterior instability is the result of rupture of the subscapularis tendon and the component position is acceptable, revising the position of the component is unnecessary. Restoring the coracoacromial arch and subacromial decompression are related to superior instability and rotator cuff pathology, respectively, and would not correct the instability caused by subscapularis rupture. Moeckel BH, Altchek DW, Warren RF, Wickiewicz TL, Dines DM: Instability of the shoulder after arthroplasty. J Bone Joint Surg Am 1993;75:492-497.

References:

Gerber C, Hersche O, Farron A: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

Question 35

A 20-year-old man has a symptomatic lesion of fibrous dysplasia in the femoral neck. Management should consist of

Explanation

Fibrous dysplasia in the femoral neck frequently warrants treatment because of the risk of pathologic fracture. Cortical strut grafts reduce the risk of local recurrence compared with cancellous bone grafting. Because of the consequences associated with fracture in this location, prophylactic fixation is recommended. Radiation therapy and chemotherapy are not used for this benign condition. Simon M, et al: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 197.

References:

Enneking WF, Gearen PF: Fibrous dysplasia of the femoral neck: Treatment by cortical bone grafting. J Bone Joint Surg Am 1986;68:1415.

Question 36

During primary total knee arthroplasty, what is the maximum distance the joint line can be raised or lowered before poor motion, joint instability, and increased chance of revision occur?

Hip 2004 Practice Questions: Set 1 (Solved) - Figure 1

Explanation

Positioning of the femoral and tibial components is a common cause of early failure of total knee arthroplasty. Two modes of possible position are raising or lowering the joint line from its anatomic level. Raising or lowering the joint line beyond an established threshold can cause limited range of motion, poor patellar function, and possible instability. It has been determined that a threshold of approximately 8 mm provides consistently good results after knee arthroplasty.

Scientific References

:

Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 339-365.

Question 37

A 42-year-old athletic trainer has a persistent popping sensation about the lateral ankle associated with weakness and pain following a remote injury. Deficiency in what structure directly leads to this pathology?

Anatomy 2008 Practice Questions: Set 1 (Solved) - Figure 15

Explanation

The patient has instability of the peroneal tendon. The superior peroneal retinaculum is the primary retaining structure preventing peroneal subluxation. It is a thickening of fascia that arises off the posterior margin of the distal 1 to 2 cm of the fibula and runs posteriorly to blend with the Achilles tendon sheath. The inferior peroneal retinaculum attaches to the peroneal tubercle of the calcaneus and is not involved in this pathology. A deficient groove in the posterior distal fibula may also be a contributing factor in the development of the condition.

References:

Maffuli N, Ferran NA, Oliva F, et al: Recurrent subluxation of the peroneal tendons. Am J Sports Med 2006;34:986-992.

Question 38

A 7-year-old boy has a limp with pain and tenderness over the distal right femur. Radiographs are shown in Figures 5a and 5b. Based on these findings, what is the best course of action?

Explanation

The patient has a nonossifying fibroma, and the symptoms suggest that there is significant weakening of the cortex and/or microfracture; therefore, biopsy, curettage, and bone grafting is the treatment of choice. Based on the size of the lesion and the presence of symptoms, observation is likely to result in pathologic fracture. A biopsy will further weaken the bone unless combined with curettage and bone grafting. Radiation therapy is not used in the treatment of nonossifying fibroma and is rarely used in any benign condition affecting skeletally immature individuals. Steroid injection has been used in the treatment of unicameral bone cysts and in Langerhan's cell histiocytosis but not for nonossifying fibroma. Dormans, JP, Pill SG: Fractures through bone cysts: Unicameral bone cysts, aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas. Instr Course Lect 2002;51:457-467.

References:

Easley ME, Kneisl JS: Pathologic fractures through nonossifying fibromas: Is prophylactic treatment warranted? J Pediatr Orthop 1997;17:808-813.

Question 39

A 24-year-old woman has a spleen laceration and hypotension. Radiographs reveal a pulmonary contusion and a displaced mid-diaphyseal fracture of the femur. The trauma surgeon clears her for stabilization of the femoral fracture. What technique will offer the least potential for initial complications?

Trauma 2000 Practice Questions: Set 1 (Solved) - Figure 28

Explanation

A concern in the multiply injured patient who has a pulmonary contusion is the potential for further pulmonary compromise because of embolization of marrow, blood clot, or fat during manipulation of the medullary canal. Recent evidence has shown that the presence of a lung injury is the most important determining factor in future deterioration. However, despite the lung injury and its potential consequences, this patient's femur fracture needs stabilization. Because damage control in the multiply injured patient requires a technique that can be performed rapidly and consistently, the treatment of choice is application of an external fixator. By placing two pins above and below the fracture and with longitudinal traction, the fracture is quickly realigned and stabilized. This allows the patient to be resuscitated and treated at a later date when definitive management of the fracture can be carried out. There is little difference between plate fixation and intramedullary nailing. Bosse MJ, MacKenzie EJ, Riemer BL, et al: Adult respiratory distress syndrome, pneumonia, and mortality following thoracic injury and a femoral fracture treated with either intramedullary nailing with reaming or with a plate: A comparative study. J Bone Joint Surg Am 1997;79:799-809. Scalea TM, Boswell SA, Scott JD, Mitchell KA, Kramer ME, Pollak AN: External fixation as a bridge to intramedullary nailing for patients with multiple injuries and with femur fractures: Damage control orthopedics. J Trauma 2000;48:613-623.

References:

Pape HC, Auf'm'Kolk M, Puffrath T, et al: Primary intramedullary femur fixation in multiple trauma patients with associated lung contusion: A cause of posttraumatic ARDS? J Trauma 1993;34:540-548.

Question 40

The vascular supply to the medial meniscus comes primarily from what artery?

Explanation

The vascular supply to the medial and lateral menisci originates predominantly from the medial and lateral genicular arteries. The popliteal artery splits into the superior genicular, which splits into medial and lateral branches supplying the patellar cartilage and the posterior cruciate ligament. The middle genicular artery also supplies the anterior curciate ligament, posterior cruciate ligament, and collateral ligaments. The inferior genicular splits into medial and lateral branches and supplies the menisci and other knee ligaments. Despite propagation of incorrect terminology, there is no superior or lateral genicular artery.

References:

Mow VC, Arnoczky SP, Jackson DW (eds): Knee Meniscus: Basic and Clinical Foundations. New York, NY, Raven Press, 1992, p 4.

Question 41

A 17-year-old basketball player and pole vaulter who has had anterior knee pain for the past 18 months now reports a recent inability to jump. Based on the MRI scan shown in Figure 11, management should consist of

Sports Medicine Board Review 2007: High-Yield MCQs (Set 2) - Figure 8

Explanation

The MRI scan reveals a partial patellar tendon rupture in conjunction with chronic patellar tendinitis. Mild and moderate patellar tendinitis may be treated nonsurgically with rest, stretching, strengthening, and anti-inflammatory drugs. Severe tendinopathy or extensor mechanism disruption is best treated surgically with tendon debridement and repair. Al-Duri ZA, Aichroth PM: Surgical aspects of patella tendonitis: Techniques and results. Am J Knee Surg 2001;14:43-50.

References:

Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 218-219.

Question 42

Which of the following tissues used for anterior cruciate ligament (ACL) reconstruction has the highest maximum load to failure?

Explanation

While the patellar tendon ligament is considered by many to be the tissue of choice for ACL reconstruction, more recent studies have shown that the quadruple semitendinosus and gracilis tendon graft has the greatest stiffness and offers the highest maximum load to failure. Hamner DL, Brown CH Jr, Steiner ME, Hecker AT, Hayes WC: Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: Biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-557. Cooper DE, Deng XH, Burstein AL, Warren RF: The strength of the central third patellar tendon graft: A biomechanical study. Am J Sports Med 1993;21:8l8-823. Brown CH Jr, Steiner ME, Carson EW: The use of hamstring tendons for anterior cruciate ligament reconstruction: Technique and results. Clin Sports Med 1993;12:723-756.

References:

Engebretsen L, Lewis JL: Graft selection and biomechanical considerations in ACL reconstruction. Sports Med Arthroscopy Rev 1996;4:336-341.

Question 43

A 12-year-old girl with juvenile rheumatoid arthritis (JRA) has had chronic pain and synovitis about the knee that is now well-controlled medically. Examination reveals 20 degrees of valgus at the knee. Knee range of motion shows 10 degrees to 90 degrees of flexion. Treatment should consist of

Explanation

Children with JRA frequently have valgus in association with hypervascularity because of chronic inflammation. This is normally caused by overgrowth of the medial femoral epiphysis. Staple hemiepiphyseodesis, if done early, can reverse the deformity. Osteotomy is usually unnecessary at this age, and there is a risk of stiffness of the knee following the procedure. Synovectomy may be helpful but will not prevent or correct a deformity.

References:

Rydholm U, Brattstrom H, Bylander B, Lidgren L: Stapling of the knee in juvenile chronic arthritis. J Pediatr Orthop 1987;7:63-68.

Question 44

Figures 22a and 22b show the radiographs of a patient who reports stiffness of the hip and associated pain. Management should consist of

Explanation

The patient has grade IV heterotopic ossification with the limb in an abnormal nonfunctional position. Treatment should consist of excision of the bone to restore hip motion and prophylaxis to prevent recurrent formation. The best time to excise the bone is controversial, with no conclusive evidence supporting early or late excision. Pellegrini VD Jr, Koniski AA, Gastel JA, Rubin P, Evarts CM: Prevention of heterotopic ossification with irradiation after total hip arthroplasty: Radiation therapy with a single dose of eight hundred centigray administered to a limited field. J Bone Joint Surg Am 1992;74:186-200.

References:

Warren SB, Brooker AF Jr: Excision of heterotopic bone followed by irradiation after total hip arthroplasty. J Bone Joint Surg Am 1992;74:201-210.

Question 45

A 10-lb, 2-oz infant who was born via a difficult breech delivery 12 hours ago is now being evaluated for hip pain. Although the infant is resting comfortably, examination reveals that the patient is not moving the right lower extremity and manipulation of the right hip causes the infant to cry. The Galeazzi sign is positive. An AP radiograph of the pelvis shows proximal and superior migration of the right proximal femoral metaphysis. What is the most likely diagnosis?

Explanation

Transphyseal fractures of the proximal femur at birth are more likely to occur in large newborns after a difficult delivery. At rest, the patients are comfortable and show a pseudoparalysis; however, passive motion of the lower extremity results in discomfort. Teratologic hip dislocations will have a positive Galeazzi sign, but are not painful. Development of a septic hip would be unlikely within 12 hours postpartum. Congenital coxa vara is typically painless. Postpartum ligamentous laxity might account for a positive Ortolani sign, but is painless. Weinstein JN, Kuo KN, Millar EA: Congenital coxa vara: A retrospective review. J Pediatr Orthop 1984;4:70-77.

References:

Beaty JH: Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 409-425.

Question 46

The lower extremity motor dysfunction in Charcot-Marie-Tooth disease most commonly involves which of the following muscles?

Explanation

The motor dysfunction in Charcot-Marie-Tooth disease involves the tibialis anterior muscle. Charcot-Marie-Tooth disorders most commonly cause distal motor dysfunction in the foot intrinsics, anterior compartment musculature, and peroneals. There is evidence that the peroneus brevis is affected selectively and the peroneus longus is spared. This is based on clinical muscle testing, muscle cross-sections on MRI, and electrodiagnostic testing. Mann RA, Missirian J: Pathophysiology of Charcot-Marie-Tooth disease. Clin Orthop 1988;234:221-228.

References:

Tynan MC, Klenerman L, Helliwell TR, Edwards RH, Hayward M: Investigation of muscle imbalance in the leg in symptomatic forefoot pes cavus: A multidisciplinary study. Foot Ankle 1992;13:489-501.

Question 47

What radiographic view will best reveal degeneration of the pisotriquetral joint in a patient who is being evaluated for pisotriquetral arthrosis?

Explanation

The pisotriquetral joint is best seen on a lateral view in 30 degrees of supination. The carpal tunnel view provides visualization of the joint but to a lesser extent. The other views do not provide clear and accurate visualization. Paley D, McMurty RY, Cruickshank B: Pathologic conditions of the pisiform and pisotriquetral joint. J Hand Surg Am 1987;12:110-119.

References:

Steinmann SP, Linsheid RL: Pisotriquetral loose bodies. J Hand Surg 1997;22:918-921.

Question 48

Thoracic disk herniations are most frequently found in what area of the spine?

Explanation

Although thoracic disk herniations have been reported at all levels of the thoracic spine, more than two thirds are found at T9-T12, which is the more mobile lower third of the thoracic region. Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.

References:

Bohlman HH, Zdeblick TA: Anterior excision of herniated thoracic discs. J Bone Joint Surg Am 1988;70:70-77.

Question 49

Figure 40 shows the radiograph of a 16-year-old wrestler who injured his elbow when he was thrown to the mat by his opponent. Closed reduction is readily accomplished, and the elbow seems stable. Management should now consist of application of a splint for

Shoulder 2002 Practice Questions: Set 3 (Solved) - Figure 20

Explanation

Flexion contractures are the most common complication of elbow dislocations. About 15% of patients lose more than 30 degrees of flexion. The risk of contracture is proportional to the duration of immobilization. Elbows should be moved within the first few days after reduction. The splinting is for comfort and protection only while the pain subsides. Mehlhoff TL, Noble PC, Bennett JB, Tullos HS: Simple dislocation of the elbow in the adult: Results after closed treatment. J Bone Joint Surg Am 1988;70:244-249. Linscheid RL, O'Driscoll SW: Elbow dislocations, in Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, pp 441-452. O'Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF: The unstable elbow. Instr Course Lect 2001;50:89-102.

References:

Ross G, McDevitt ER, Chronister R, Ove PN: Treatment of simple elbow dislocation using an immediate motion protocol. Am J Sports Med 1999;27:308-311.

Question 50

In the radiograph shown in Figure 42, the fracture pattern around this well-fixed stem is classified as Vancouver type

Hip & Knee Reconstruction 2007 Practice Questions: Set 3 (Solved) - Figure 16

Explanation

The Vancouver classifications describes periprosthetic hip fractures in the following way. Type A fractures are in the trochanteric region. Type B1 fractures occur around the stem or at the tip in the face of a well-fixed stem. These are usually treated with open reduction and internal fixation, usually including struts, cable, and/or cable plates. Type B2 fractures occur in the same region with a loose stem. Type B3 fractures occur with a loose stem where the proximal bone is of poor quality and/or severely comminuted. Type C fractures occur well below the stem. Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 149-154. Parvizi J, Rapuri VR, Purtill JJ, et al: Treatment protocol for proximal femoral periprosthetic fractures. J Bone Joint Surg Am 2004;86:8-16.

References:

Masri BA, Meek RM, Duncan CP: Periprosthetic fractures evaluation and treatment. Clin Orthop 2004;420:80-95.

Question 51

Stability at the atlanto-occipital joint is provided mainly by

Explanation

The atlanto-occipital joint is inherently unstable and would easily dislocate without the supporting ligaments. The apical ligament attaches to the basion and tip of the dens but does not provide adequate stability to the joint. Werne demonstrated that dividing the tectorial membrane and the alar ligaments resulted in gross joint instability. The anterior longitudinal ligament turns into the anterior atlanto-occipital membrane. This is called a membrane rather than a ligament because it is not strong enough to support these two structures. Werne S: Studies in spontaneous atlas dislocation. Acta Orthopaedica Scandinavica 1977;23(supplement).

References:

Jarrett PJ, Whitesides TE Jr: Injuries of the cervicocranium, in Browner BD, Jupiter JB, Levine AM, Trafton PG (eds): Skeletal Trauma. Philadelphia, PA, WB Saunders, 1992, pp 665-697.

Question 52

A 65-year-old man who underwent cemented right total hip arthroplasty 6 years ago now reports acute pain for the past week. He denies any trauma, recent illnesses, or symptoms other than pain. Plain radiographs show possible loosening of the femoral component. A normal result from which of the following studies will most specifically rule out infection?

Explanation

A patient with an infected total hip arthroplasty may lack the symptoms of fever, chills, redness, or increased warmth typical of septic arthritis. Sensitivity for ESR and CRP ranges from 61% to 96%, and specificity ranges from 85% to 100%. Technetium Tc 99m bone scans are costly and time-consuming and will not differentiate between septic and aseptic loosening. Hip aspiration has a false-positive rate of up to 15%, although it may be useful in this patient to further complement the clinical picture if the ESR and CRP are elevated. The WBC count is rarely elevated in infected total hip arthroplasty. MRI is expensive and is not indicated for the diagnosis; however, it can aid in identifying intrapelvic extension of a periprosthetic abscess. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 455-492.

References:

Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 137-148.

Question 53

A 14-year-old boy sustained a femoral neck fracture in a fall from a tree and underwent open reduction and internal fixation 6 months ago. Follow-up examination now reveals an antalgic Trendelenburg gait and painful range of motion. A radiograph is shown in Figure 23, and a CT scan shows a nonunion. Treatment should consist of

Pediatrics Board Review 2001: High-Yield MCQs (Set 2) - Figure 11

Explanation

The coxa vara deformity and fracture nonunion should be treated simultaneously; therefore, the treatment of choice is curettage of the nonunion, intertrochanteric valgus osteotomy, and revision internal fixation. In addition, valgus osteotomy will convert the shear forces across the nonunion to compression, aiding in healing of the nonunion. None of the other procedures addresses both issues, and hip fusion is inappropriate under these conditions. Lam SF: Fractures of the neck of the femur in children. J Bone Joint Surg Am 1971;53:1165-1179.

References:

Canale ST, Beaty JH: Pelvic and hip fractures, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children. Philadelphia, Pa, Lippincott-Raven, 1996, pp 1109-1193.

Question 54

What complication is frequently associated with the Weil lesser metatarsal osteotomy (distal, oblique) in the treatment of claw toe deformities?

Explanation

Weil osteotomies are useful in achieving shortening of a lesser metatarsal with preservation of the distal articular surface. The osteotomy is oriented from distal-dorsal to proximal-plantar; therefore, proximal displacement of the distal fragment is associated with plantar (not dorsal) displacement as well. Plantar displacement can result in the intrinsics acting dorsal to the center of the metatarsophalangeal joint and the development of an extended or "floating toe." Nonunion, osteonecrosis, and inadequate shortening are infrequent complications associated with the Weil lesser metatarsal osteotomy. Trnka HJ, Nyska M, Parks BG, et al: Dorsiflexion contracture after the Weil osteotomy: Results of cadaver study and three-dimensional analysis. Foot Ankle Int 2001;22:47-50.

References:

Trnka HJ, Muhlbauer M, Zettl R, et al: Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints. Foot Ankle Int 1999;20:72-79.

Question 55

A 37-year-old man with a history of congenital flatfoot reports worsening pain on the medial aspect of his ankle for the past year. The pain is worse with weight bearing and is better with rest and the use of an ankle brace. What findings are shown on the MRI scans shown in Figures 18a through 18c?

Explanation

The MRI scans reveal an enlarged posterior tibial tendon, with degenerative signal within the tendon and an excessive amount of fluid in its sheath. This is a type II tear, as noted by Conti and associates, which is the most commonly seen tear. Slovenkai MP: Clinical and radiographic evaluation (Adult flatfoot: Posterior tibial tendon dysfunction). Foot Ankle Clin 1997;2:241-260.

References:

Conti S, Michelson J, Jahss M: Clinical significance of magnetic resonance imaging in preoperative planning for reconstruction of posterior tibial tendon ruptures. Foot Ankle 1992;13:208-214.

Question 56

A 5-year-old boy has had midfoot pain with activity for the past 3 months. He has no pain at rest. Radiographs are shown in Figures 29a and 29b. Management should consist of

Explanation

The radiographs show classic findings for Koehler's disease (osteochondrosis of the navicular). The patient's age and clinical history are typical for this self-limiting condition. Patients will improve with time, but the duration of symptoms is much shorter if the patient is placed in a cast. There is no role for surgery in this disease.

References:

Williams GA, Cowell HR: Koehler's disease of the tarsal navicular. Clin Orthop 1981;158:53-58.

Question 57

What is the most common cause for poor outcomes in patients who undergo total shoulder arthroplasty?

Upper Extremity 2008 Practice Questions: Set 1 (Solved) - Figure 30

Explanation

In an article in the Journal of Shoulder and Elbow, 431 total shoulder arthroplasties were performed with a cemented all-polyethylene glenoid component between 1990 and 2000. Follow-up averaged 4.2 years. In total, 53 surgical complications occurred in 53 patients (12%). Of these, 32 were major complications (7.4%), with 17 of these requiring reoperation. Index complications in order of frequency included rotator cuff tearing, postoperative glenohumeral instability, and periprosthetic humeral fracture. Notably, glenoid and humeral component loosening requiring reoperation occurred in only one shoulder. Data from the contemporary patient group suggest that there are fewer complications of shoulder arthroplasty and less need for reoperation. Especially striking is the near absence of component revision because of loosening or other mechanical factors. Complications involving the brachial plexus have been reported following total shoulder arthroplasty but are not as common of a cause for failure. Chin PY, Sperling JW, Cofield RH, et al: Complications of total shoulder arthroplasty: Are they fewer or different? J Shoulder Elbow Surg 2006;15:19-22.

References:

Hasan SS, Leith JM, Campbell B, et al: Characteristics of unsatisfactory shoulder arthroplasties. J Shoulder Elbow Surg 2002;11:431-441.

Question 58

A 29-year-old woman who underwent an anterior cruciate ligament (ACL) reconstruction 6 months ago now reports difficulty achieving full knee extension, and physical therapy fails to provide relief. The knee is stable on ligament testing. Figure 3 shows the findings at a repeat arthroscopy. Treatment should now include

Sports Medicine 2001 Practice Questions: Set 1 (Solved) - Figure 6

Explanation

The patient has a cyclops lesion. This is a nodule of fibroproliferative tissue that originates from either drilling debris from the tibial tunnel or remnants of the ACL stump; more rarely it is the result of broken graft fibers. The treatment of choice is excision of the nodule and, if needed, additional notchplasty. Marked improvements in function and symptoms have been noted after removal of the extension block and resumption of a rehabilitation program. Delince P, Krallis P, Descamps PY, et al: Different aspects of the cyclops lesion following anterior cruciate ligament reconstruction: A multifactorial etiopathogenesis. Arthroscopy 1998;14:869-876.

References:

Fisher SE, Shelbourne KD: Arthroscopic treatment of symptomatic extension block complicating anterior cruciate ligament reconstruction. Am J Sports Med 1993;4:558-564.

Question 59

A 12-year-old girl who is Risser stage 3 has had intermittent mild midback pain for the past 4 weeks. The pain is worse after prolonged sitting and after carrying a heavy backpack at school. She occasionally takes acetaminophen, but the pain does not limit sport activities. Examination reveals a mild right rib prominence during forward bending. Neurologic examination is normal. Radiographs show a 20-degree right thoracic scoliosis with no congenital anomalies or lytic lesions. Management should consist of

Explanation

Mild scoliosis is not a painful condition, but it usually presents during adolescence. Intermittent back pain is reported by 25% to 30% of adolescents whether or not scoliosis is present. Such pain is often attributed to muscle strain from tight muscles, poor posture, or heavy school backpacks. The clinician must distinguish typical pain (mild, intermittent, nonlimiting) from atypical pain. The latter requires more careful examination and imaging studies (bone scan or MRI) to determine the source of pain. The patient's age and right thoracic curve pattern are typical for idiopathic scoliosis; therefore, imaging of the neuroaxis is not necessary to look for cord syrinx, tethering, or tumor. Brace treatment is not required for this small curve unless future progression is demonstrated. Ramirez N, Johnston CE, Browne RH: The prevalence of back pain in children who have idiopathic scoliosis. J Bone Joint Surg Am 1997;79:364-368. Hollingworth P: Back pain in children. Br J Rheum 1996;35:1022-1028.

References:

Siambanes D, Martinez JW, Butler EW, et al: Influence of school backpacks on adolescent back pain. J Pediatr Orthop 2004;24:211-217.

Question 60

A 30-year-old firefighter sustained a longitudinal pulling injury to the arm while attempting to move a heavy object during a fire. Figure 45 shows an MRI scan of the elbow. Initial management should consist of

Shoulder Board Review 2002: High-Yield MCQs (Set 4) - Figure 9

Explanation

Because the MRI scan shows a complete rupture of the distal biceps tendon, the preferred treatment is anatomic repair of the tendon to the radial tuberosity either with the use of suture anchors or transosseous sutures through a two-incision technique. Several studies have documented superior results with anatomic repair of the distal biceps tendon when compared with results of nonsurgical management or repair of the tendon by attachment to the brachialis muscle. Patients undergoing anatomic repair of the distal biceps tendon through a two-incision technique typically regain a functional range of motion and nearly normal strength. D'Alessandro DF, Shields CL Jr, Tibone JE, Chandler RW: Repair of distal biceps tendon ruptures in athletes. Am J Sports Med 1993;21:114-119. Boyd JB, Anderson LD: A method for reinsertion of the distal biceps brachii tendon. J Bone Joint Surg Am 1961;43:1041-1043. Morrey BF, Askew LJ, An KN, Dobyns JH: Rupture of the distal tendon of the biceps brachii: A biomechanical study. J Bone Joint Surg Am 1985;67:418-421.

References:

Failla JM, Amadio PC, Morrey BF, Beckenbaugh RD: Proximal radioulnar synostosis after repair of distal biceps brachii rupture by the two-incision technique: Report of four cases. Clin Orthop 1990;253:133-136.

Question 61

Figures 14a and 14b show the initial radiographs of an 18-year-old man who fell while snowboarding. Figures 14c and 14d show the radiographs obtained following closed reduction. Examination reveals that the elbow is stable with range of motion. Management should now consist of

Explanation

The initial radiographs reveal a simple elbow dislocation without associated fractures. After successful closed reduction, the range of stability should be assessed. If the elbow is stable, nonsurgical management should consist of a short period of immobilization followed by range-of-motion exercises. Immobilization for more than 3 weeks results in significant elbow stiffness. Surgical repair is indicated for dislocations that are irreducible, have associated fractures, or where stability cannot be maintained with closed treatment. Cohen MS, Hastings H II: Acute elbow dislocations: Evaluation and management. J Am Acad Orthop Surg 1998;6:15-23.

Scientific References

:

O'Driscoll SW: Elbow dislocations, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 409-420.

Question 62

A 22-year-old wrestler who underwent an open anterior shoulder reconstruction to repair a dislocated shoulder 6 months ago now reports shoulder pain after attempting a takedown. Examination reveals external rotation that is 15 degrees greater than the contralateral side. He has pain associated with abduction and external rotation but no apprehension. Which of the following tests would most likely reveal positive findings?

Explanation

Postoperative subscapularis detachment can be identified with a positive lift-off test that reveals weakness in internal rotation. This complication does not necessarily compromise the anterior capsule repair. The load-and-sift maneuver and articular contrast studies may be normal. Supraspinatus tests for impingement and weakness should be negative. Gerber C, Krushell RJ: Isolated ruptures of the tendon of the subscapularis muscle: Clinical fractures in 16 cases. J Bone Joint Surg Br 1991;73:389-394.

References:

Hawkins RJ, Bokor DJ: Clinical evaluation of the shoulder, in Rockwood CA, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, pp 149-177.

Question 63

Which of the following radiographic images is best for detecting anterior acetabular deficiency in the dysplastic hip?

Anatomy 2008 Practice Questions: Set 1 (Solved) - Figure 19

Explanation

The false profile view of Lequesne and de Seze is obtained with the patient standing with the affected hip on the cassette, the ipsilateral foot parallel to the cassette, and the pelvis rotated 65 degrees from the plane of the cassette. This view best assesses anterior coverage of the femoral head. Garbuz DS, Masri BA, Haddad F, et al: Clinical and radiographic assessment the young adult with symptomatic dysplasia. Clin Orthop Relat Res 2004;418:18-22.

References:

Delauney S, Dussault RG, Kaplan PA, et al: Radiographic measurements of dysplastic adult hips. Skelelal Radiol 1997;26:75-81.

Question 64

Figures 5a and 5b show the radiographs of an 11-year-old boy who felt a pop and immediate pain in his right knee as he was driving off his right leg to jam a basketball. Examination reveals that the knee is flexed, and the patient is unable to actively extend it or bear weight on that side. There is also a large effusion. Management should include

Explanation

Fractures through the cartilage on the inferior pole of the patella, the so-called sleeve fracture, are often difficult to diagnose because of the paucity of ossified bone visible on the radiographs. If the fracture is missed and the fragments are widely displaced, the patella may heal in an elongated configuration that may result in compromise of the extensor mechanism function. The treatment of choice is open reduction and internal fixation using a tension band wire technique to achieve close approximation of the fragments and restore full active knee extension. Heckman JD, Alkire CC: Distal patellar pole fractures: A proposed common mechanism of injury. Am J Sports Med 1984;12:424-428.

References:

Tolo VT: Fractures and dislocations around the knee, in Green NE, Swiontkowski MF (eds): Skeletal Trauma in Children. Philadelphia, Pa, WB Saunders, 1994, vol 3, pp 380-382.

Question 65

When compared with a patient who has a subluxated hip, a patient with a dislocated hip who is undergoing acetabular reconstruction for developmental dysplasia of the hip will most likely have

Hip 2001 Practice Questions: Set 1 (Solved) - Figure 19

Explanation

The rate of revision has been found to be significantly increased in patients with a dislocated hip preoperatively compared with patients with a subluxated hip. This may be the result of compromised acetabular bone stock. The rate of nerve palsy may be increased because of the greater degree of lengthening required to reduce the reconstructed hip. Numair J, Joshi AB, Murphy JC, Porter ML, Hardinge K: Total hip arthroplasty for congenital dysplasia or dislocation of the hip: Survivorship analysis and long-term results. J Bone Joint Surg Am 1997;79:1352-1360.

References:

Schmalzried TP, Noordin S, Amstutz HC: Update on nerve palsy associated with total hip replacement. Clin Orthop 1997;344:188-206.

Question 66

A patient who underwent open reduction and internal fixation of an olecranon fracture 2 months ago now reports painless limitation of motion. Examination reveals a well-healed incision and a flexion-extension arc from 40 degrees to 80 degrees. The patient has been performing home exercises. Radiographs are shown in Figures 26a and 26b. What is the most appropriate treatment?

Explanation

The radiographs do not show an articular malunion. Treatment is directed at the soft-tissue contracture and should begin with formal physical therapy and static progressive splinting. Radiation therapy is effective in the perioperative period and is indicated when ectopic bone formation is a concern. Morrey BF: The posttraumatic stiff elbow. Clin Orthop Relat Res 2005;431:26-35.

References:

King GJ, Faber KJ: Posttraumatic elbow stiffness. Orthop Clin North Am 2000;31:129-143.

Question 67

A 16-year-old high school student undergoes a routine preparticipation physical examination at the beginning of the school year. Examination reveals marked laxity of both shoulders but only mild generalized laxity in other joints. The load and shift test allows for anterior humeral translation to the glenoid rim and posterior humeral translation beyond the glenoid rim. The sulcus sign is present. What is the next most appropriate step in management?

Explanation

This patient has shoulder laxity without apprehension. Because there is a wide range of normal laxity in asymptomatic shoulders, the physician should inform the student of these findings, recommend shoulder strengthening exercises, and allow unrestricted sports participation unless symptoms develop. Harryman DT, Sidles JA, Harris SL, Matsen FA III: Laxity of the normal glenohumeral joint: A quantitative in vivo assessment. J Shoulder Elbow Surg 1992;1:66-76. Hawkins RJ, Bokor RJ: Clinical evaluation of shoulder problems, in Rockwood CA Jr, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1998, vol 1, p 186. McFarland EG, Campbell G, McDowell J: Posterior shoulder laxity in asymptomatic athletes. Am J Sports Med 1996;24:468-471.

References:

Linter SA, Levy A, Kenter K, Speer KP: Glenohumeral translation in the asymptomatic athlete's shoulder and its relationship to clinically measurable anthropometric variables. Am J Sports Med 1996;24:716-720.

Question 68

A 3-year-old child has refused to walk for the past 2 days. Examination in the emergency department reveals a temperature of 102.2 degrees F (39 degrees C) and limited range of motion of the left hip. An AP pelvic radiograph is normal. Laboratory studies show a WBC count of 9,000/mm3, an erythrocyte sedimentation rate (ESR) of 65 mm/h, and a C-reactive protein level of 10.5 mg/L (normal < 0.4). What is the next most appropriate step in management?

Explanation

Examination reveals an irritable hip, creating a differential diagnosis of transient synovitis versus pyogenic hip arthritis. Kocher and associates described four criteria to help predict the presence of infection: inability to bear weight, fever, ESR of more than 40 mm/h, and a peripheral WBC count of more than 12,000/mm3. This patient meets three of the four criteria, with a positive predictive value of 73% to 93% for joint infection. Therefore, aspiration of the hip is warranted, with a high likelihood that emergent hip arthrotomy will be indicated. Ideally, intravenous antibiotics should be administered after culture material has been obtained from needle aspiration of the hip. An urgent bone scan is better indicated as a screening test for sacroiliitis or diskitis. If the arthrocentesis proves negative, CT or MRI of the pelvis may be indicated to rule out a pelvic or psoas abscess. Del Beccaro MA, Champoux AN, Bockers T, et al: Septic arthritis versus transient synovitis of the hip: The value of screening laboratory tests. Ann Emerg Med 1992;21:1418-1422. Kocher MS, Mandiga R, Zurakowski D, et al: Validation of a clinical prediction rule for the differentiation between septic arthritis and transient synovitis of the hip in children. J Bone Joint Surg Am 2004;86:1629-1635.

References:

Kocher MS, Zurakowski D, Kasser JR: Differentiating between septic arthritis and transient synovitis of the hip in children: An evidence-based clinical prediction algorithm. J Bone Joint Surg Am 1999;81:1662-1670.

Question 69

A 14-year-old football player has had thigh pain and weakness following a full-contact scrimmage 24 hours ago. He recalls that he felt a sharp pain in his back after colliding with a much heavier player. Examination reveals that the spine is minimally tender to palpation in the upper lumbar region. Motor testing reveals quadriceps weakness bilaterally, and a reverse straight leg raising test is positive. Plain radiographs of the thoracolumbar spine are normal. A myelogram, a CT scan with contrast, and an MRI scan are shown in Figures 41a through 41c. What is the most likely diagnosis?

Explanation

Fracture of the vertebral end plate is a relatively uncommon injury that is most often seen in adolescent boys. The injury is characterized by traumatic displacement of the vertebral ring-apophysis into the spinal canal and associated disk herniation. Over one third of these injuries are seen in children with lumbar Scheuermann disease. The injury most frequently involves the midlumbar vertebra, and symptoms are often indistinguishable from those associated with a herniated disk. The injury is usually not visible on plain radiographs. The diagnosis is typically made after obtaining MRI or contrast CT scans. Treatment consists of laminotomy and excision of the osteochondral fragments. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 635-651.

References:

Epstein NE, Epstein JA, Mauri T: Treatment of fractures of the vertebral limbus and spinal stenosis in five adolescents and five adults. Neurosurgery 1989;24:595-604.

Question 70

A collegiate rower reports the sudden onset of right chest pain while rowing. The athlete states that the pain is worse with deep inspiration and coughing. Examination reveals localized tenderness over the posterolateral corner of the eighth rib. What is the most likely diagnosis?

Sports Medicine Board Review 2004: High-Yield MCQs (Set 2) - Figure 12

Explanation

A rib stress fracture, the most common injury to the thorax in rowing athletes, generally occurs during periods of intense training with a low stroke rate and heavy loads. It is characterized by the sudden onset of sharp, localized chest pain while rowing. The fifth through the ninth rib is generally affected, and the diagnosis is best established with a bone scan. An intercostal muscle strain generally has an insidious onset and may be poorly localized. Costochondritis affects the anterior costochondral junction. A pneumothorax and an empyema can cause nonlocalized chest pain but are associated with respiratory distress and systemic physical findings. Karlson KA: Rib stress fractures in elite rowers. Am J Sports Med 1998;26:516-520.

References:

Holden DL, Jackson DW: Stress fractures of the ribs in female rowers. Am J Sports Med 1985;13:342-348.

Question 71

Consider the theoretic articulation shown in Figure 11 as femoral and tibial components of a total knee prosthesis in which the components fit like a "roller in trough." Which of the following best describes the articulation?

Hip Board Review 2004: High-Yield MCQs (Set 2) - Figure 7

Explanation

The theoretic total knee components will resist anteroposterior motion by making the femoral component "climb the walls" of the tibial component. As drawn, there is no constraint to medial-lateral translation. The cylinder is not rounded on the edges, so varus-valgus motion will impart load from the cylinder to the trough over a small area, thus having a high contact stress.

References:

Alicea J: Scoring systems and their validation for the arthritic knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2, pp 1507-1515.

Question 72

A nonambulatory verbal 6-year-old child with spastic quadriplegic cerebral palsy has progressive bilateral hip subluxation of more than 50%. There is no pain with range of motion, but abduction is limited to 20 degrees maximum. An AP radiograph is seen in Figure 34. Management should consist of

Pediatrics Board Review 2007: High-Yield MCQs (Set 4) - Figure 2

Explanation

The natural history of the patient's hips, if left untreated, is gradual progression to dislocation. To prevent future pain, prevention of dislocation is often helpful. The patient is too old for soft-tissue releases alone. Therefore, the treatment of choice is medial release of both hips to obtain 45 degrees or better of hip abduction in conjunction with psoas tenotomy and bilateral femoral varus osteotomies. Presedo A, Oh CW, Dabney KY, et al: Soft-tissue releases to treat spastic hip subluxation in children with cerebral palsy. J Bone Joint Surg Am 2005;87:832-841.

References:

Miller F, Bagg MR: Age and migration percentage as risk factors for progression in spastic hip disease. Dev Med Child Neurol 1995;37:449-455.

Question 73

A biopsy of the involved physis in a patient with slipped capital femoral epiphysis (SCFE) would most likely reveal

Explanation

Vascular invasion, histologically similar to granulation tissue, has been noted between the columns in the zone of hypertrophy, leading to the theory of microtrauma as an etiology. SCFE is also associated with conditions that increase the height of the zone of hypertrophy, including the adolescent growth spurt and endocrinopathies. The perichondral ring has been shown to decrease in thickness with age. Normal undulations in the growth plate also decrease during this time, possibly further destabilizing the physis. Abnormal accumulations of proteoglycan have been reported. Chung SM, Batterman SC, Brighton CT: Shear strength of the human femoral capital epiphyseal plate. J Bone Joint Surg Am 1976;58:94-103.

References:

Raney EM, Ogden JA: Slipped capital femoral epiphysis. Current Ortho 1995;9:111-116.

Question 74

A 28-year-old man sustained a fracture-dislocation of T8 in a motor vehicle accident 1 week ago. The injury resulted in complete paraplegia. Management should consist of

Trauma 2000 Practice Questions: Set 1 (Solved) - Figure 32

Explanation

With a complete injury in the thoracic spinal cord, the likelihood of neurologic recovery is small. If possible, treatment should be planned to allow rapid mobilization and rehabilitation without the use of braces and their associated skin problems. The use of long segment fixation provides for rapid mobilization without having to use braces postoperatively. The use of steroid protocol is controversial and should be considered only if it can be started within 8 hours of the injury. Laminectomy is contraindicated because it will increase instability.

References:

Tasdemiroglu E, Tibbs PA: Long-term follow-up results of thoracolumbar fractures after posterior instrumentation. Spine 1995;20:1704-1708.

Question 75

Which of the following agents increases the risk for a nonunion following a posterior spinal fusion?

Explanation

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to increase the risk of pseudarthrosis. In a controlled rabbit study, nonunions were reported with the use of toradol and indomethacin. NSAIDs are commonly used medications with the potential to diminish osteogenesis. Studies clearly have demonstrated inhibition of spinal fusion following the postoperative administration of several NSAIDs, including ibuprofen. Cigarette smoking is another potent inhibitor of spinal fusion. Glassman SD, Rose SM, Dimar JR, et al: The effect of postoperative nonsteroidal anti-inflammatory drug administration on spinal fusion. Spine 1998;23:834-838.

References:

Martin GJ Jr, Boden SD, Titus L: Recombinant human bone morphogenetic protein-2 overcomes the inhibitory effect of ketorolac, a nonsteroidal anti-inflammatory drug (NSAID), on posterolateral lumbar intertransverse process spine fusion. Spine 1999;24:2188-2193.

Question 76

A 70-year-old woman has a preoperative anterior interscalene block prior to undergoing a total shoulder arthroplasty. After seating her in the beach chair position, she becomes acutely hypotensive. What is the most likely cause for the hypotension?

Explanation

The beach chair position may cause sudden hypotension and bradycardia as a result of the Bezold-Jarisch reflex. This reflex occurs when venous pooling and increased sympathetic tone induce a low-volume, hypercontractile ventricle, resulting in activation of the parasympathetic nervous system and sympathetic withdrawal. The reported incidence of this phenomenon associated with the sitting position is between 13% to 24%. Left untreated, the result may be cardiac arrest. Pneumothorax or central nervous system toxicity after interscalene block is rare and has an incidence of less than 0.2%. Laryngeal nerve block associated with interscalene nerve block can occur but usually results in hoarseness secondary to ipsilateral vocal cord palsy. Long T, Wass C, Burkle C: Perioperative interscalene blockade: An overview of its history and current clinical use. J Clin Anesthesia 2002;14:546-556.

References:

Norris T (ed): Orthopaedic Knowledge Update: Shoulder and Elbow 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 433-442.

Question 77

The parents of a previously healthy 3-year-old child report that she refused to walk on awakening. Examination later in the day reveals that the patient can walk but with a noticeable limp. She has a temperature of 99.5 degrees F (37.5 degrees C). Range of motion measurements are shown in Figure 50. An AP pelvis radiograph is normal. Laboratory studies show a WBC count of 9,000/mm3 and an erythrocyte sedimentation rate of 10 mm/h. Management should consist of

Pediatrics Board Review 2004: High-Yield MCQs (Set 4) - Figure 16

Explanation

The patient has the typical history and presentation of transient synovitis of the hip, a condition that is more common in children age 2 to 5 years but which may affect children up to 12 years. The discomfort typically is noted on awakening, and the child will refuse to walk. Later in the day, the pain commonly improves and the child can walk but will have a limp. Mild to moderate restriction of hip abduction is the most sensitive range-of-motion restriction. The extent of the evaluation for transient synovitis depends on the intensity and duration of symptoms. Because she has been afebrile for the past 24 hours, observation is the management of choice. In the differential diagnosis of suspected transient synovitis, septic arthritis of the hip is the primary disorder to exclude. Osteomyelitis of the proximal femur also should be considered. In most patients, clinical examination will differentiate of these disorders to a reasonable certainty. Plain radiographs are normal in the early stage of an infectious process. Ultrasonography shows increased fluid in the hip joint in both transient synovitis and septic arthritis. MRI can differentiate the two conditions; however, this test would require general anesthesia and is not required in most patients in this age group. If a child with transient synovitis has a concurrent infectious process such as an upper respiratory tract infection or otitis media, the temperature will most likely be elevated. In this situation, a full evaluation for an infectious process and initiation of IV antibiotics should be considered. This would include radiographs, CBC count, erythrocyte sedimentation rate, blood cultures, aspiration of the hip joint, and IV antibiotics. Del Beccaro MA, Champoux AN, Bockers T, Mendelman PM: Septic arthritis versus transient synovitis of the hip: The value of screening laboratory tests. Annals Emerg Med 1992;21:1418-1422.

References:

Kehl DK: Developmental coxa vara, transient synovitis, and idiopathic chondrolysis of the hip, in Morrissy RT, Weinstein SL (eds): Lovell and Winter's Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 1035-1058.

Question 78

What is the recommended insertion torque for halo pins in adults?

Spine Surgery 2006 Practice Questions: Set 1 (Solved) - Figure 17

Explanation

Garfin and associates have shown that halo pins inserted with 8 in-lb of insertion torque results in significantly less loosening with cyclical loading than pins inserted with 6 in-lb of torque. Moreover, Botte and associates reported that 8 in-lb of torque is clinically safe and effective in lowering the incidence of pin loosening and infection. Botte MJ, Byrne TP, Garfin SR: Application of the halo device for immobilization of the cervical spine utilizing an increased torque pressure. J Bone Joint Surg Am 1987;69:750-752. Garfin SR, Lee TO, Roux RD, et al: Structural behavior of the halo orthosis pin-bone interface: Biomechanical evaluation of standard and newly designed stainless steel halo fixation pins. Spine 1986;11:977-981.

References:

Vaccaro AR, Botte MD, Bengt IL, et al: Cervical orthotics including traction and halo devices, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 113-140.

Question 79

An 82-year-old woman fell on her right shoulder 2 days ago. She is alert, oriented, and in mild discomfort. Prior to falling, she lived alone and functioned independently. Examination reveals extensive ecchymosis extending to the midhumeral region. Her neurovascular examination is normal. Radiographs are shown in Figures 41a and 41b. What is the most appropriate management?

Explanation

The patient has a displaced four-part proximal humerus fracture. Given her age and the presence of osteopenia, a cemented hemiarthroplasty is the treatment of choice. The glenoid is uninjured so a total shoulder arthroplasty is not indicated. Percutaneous pinning in younger individuals with good bone quality may be indicated but not in an 82-year-old woman with osteopenia. Sling immobilization and immediate pendulum exercises will lead to a nonunion. Sling immobilization for 6 weeks followed by active range of motion will result in a nonunion or malunion with unacceptable functional results. Neer CS II: Displaced proximal humeral fractures: I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-1089.

References:

Bigliani LU, Flatow EL, Pollock RG: Fractures of the proximal humerus, in Rockwood CA Jr, Matsen FA III (eds): Rockwood and Matsen The Shoulder, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 352-354.

Question 80

An 20-year-old elite college football player has ecchymosis, swelling, and pain on the lateral side of his foot after a game. Radiographs are shown in Figures 31a through 31c. Management should consist of

Explanation

Metaphyseal-diaphyseal junction fractures of the fifth metatarsal require careful evaluation. In athletes, early intervention with a 4.5-mm intramedullary screw correlates with an earlier return to activity. One study examining the failure of surgically managed Jones fractures revealed that use of anything other than a 4.5-mm malleolar screw for internal fixation correlated with failure. Glasgow MT, Naranja RJ Jr, Glasgow SG, et al: Analysis of failed surgical management of fractures of the base of the fifth metatarsal distal to the tuberosity: The Jones fracture. Foot Ankle Int 1996;17:449-457.

References:

Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 243-252.

Question 81

A 64-year-old man undergoes a primary total knee arthroplasty. Three months after surgery he reports persistent pain, weakness, and difficulty ambulating. Postoperative radiographs are shown in Figures 6a through 6c. What is the best course of action at this time?

Explanation

The Merchant view reveals subluxation of the patellar component. The etiology of maltracking of the patella includes internal rotation of the femoral component, internal rotation of the tibial component, excessive patellar height, and lateralization of the patella component. The treatment of choice in this patient is revision total knee arthroplasty with external rotation of the femoral component. Preoperatively the patient also may require a lateral release, revision of the tibial component if it is internally rotated, and possibly a soft-tissue realignment. Component malalignment needs to be addressed first. Kelly MA: Extensor mechanism complications in total knee arthroplasty. Instr Course Lect 2004;53:193-199. Malkani AL, Karandikar N: Complications following total knee arthroplasty. Sem Arthroplasty 2003;14:203-214.

References:

Norman AJ, Scott S, David GN (eds): Master Techniques in Knee Arthroplasty, ed 2. Philadelphia, PA, Lippincott Williams & Wilkins, 2003.

Question 82

A 28-year-old man sustained numerous injuries in an accident including a dislocation of the elbow and a severe closed head injury that resulted in unconsciousness. The elbow was reduced in the emergency department. After 1 month of rehabilitation, the patient reports pain and stiffness. A radiograph is shown in Figure 23. Management should now consist of

Upper Extremity 2005 Practice Questions: Set 3 (Solved) - Figure 2

Explanation

In a young individual with a chronic dislocation of the elbow and heterotopic bone formation, the treatment of choice is open reduction, heterotopic bone excision, anterior and posterior capsular releases, and a dynamic hinged fixator to begin protected early postoperative range of motion. It is important to understand that the fixator protects the reconstruction and allows early range of motion, but it does not maintain the reduction and should not be expected to do so. Pin fixation across the elbow delays early motion and is not recommended. Total elbow arthroplasty is not indicated, and ulnohumeral arthroplasty is for a primary arthritic condition. Garland DE, Hanscom DA, Keenan MA, et al: Resection of heterotopic ossification in the adult with head trauma. J Bone Joint Surg Am 1985;67:1261-1269.

References:

Moor TJ: Functional outcome following surgical excision of heterotopic ossification in patients with traumatic brain injury. J Orthop Trauma 1993;7:11-14.

Question 83

The injection shown in Figures 1a and 1b would most benefit a patient who reports which of the following symptoms?

Explanation

The images demonstrate a L5 selective root block as it exits the L5-S1 foramen. This root block best helps relieve pain or paresthesias in the L5 distribution, which is the dorsal first web space and the great toe. The lateral foot is an S1 distribution and would need to be blocked through the posterior first sacral foramen. The anterior shin and thigh represent the L4 root which exits a level above this at the L4-5 foramen. A stocking distribution is nonanatomic and not indicative of a specific root. Magee D: Principles and concepts, in Orthopaedic Physical Assessment, ed 3. Philadelphia, PA, WB Saunders, 1997, pp 1-18.

References:

Aeschbach A, Mekhail NA: Common nerve blocks in chronic pain management. Anesthesiol Clin North Am 2000;18:429-459.

Question 84

A 13-year-old boy has had a painless mass in the arm for the past 2 months. An MRI scan and biopsy specimens are shown in Figures 46a through 46c. What is the most likely diagnosis?

Explanation

Nodular fasciitis is a benign soft-tissue lesion that usually arises from the fascia and is often misdiagnosed as a sarcoma. Desmoid tumors (aggressive fibromatosis) are also benign tumors with a greater tendency for local recurrence. Desmoid tumors have more spindle-shaped fibroblasts in an abundant collagenous matrix. Malignant fibrous histiocytoma is a hypercellular pleomorphic sarcoma more commonly found in adults. The histology is not consistant with a fatty tumor.

References:

Bernstein KE, Lattes R: Nodular (pseudosarcomatous) fasciitis, a nonrecurrent lesion: Clinicopathologic study of 134 cases. Cancer 1982;49:1668-1678.

Question 85

What is the most common short-term complication following femoral impaction grafting for revision total hip arthroplasty?

Explanation

Impaction grafting is an alternative for severe femoral bone deficiency; however, stem subsidence is commonly observed during the first few months. Slight subsidence is felt to be integral to the success of the procedure. Predictable bone graft incorporation and stable stem fixation have been reported in the medium-term. The incidence of periprosthetic fractures has been reported as high as 24%. Mikhail MWE, Weidenhielm L, Jazrawi LM, et al: Collarless, polished, tapered stem failure. J Bone Joint Surg Am 2000;82:1513-1514.

References:

Leopold SS, Rosenberg AG: Current status of impaction allografting for revision of a femoral component. Instr Course Lect 2000;49:111-118.

Question 86

A college basketball player is struck in the eye by a player's hand while driving to the basket. Fluorescein evaluation reveals the injury shown in Figure 18. Management should consist of

Sports Medicine Board Review 2001: High-Yield MCQs (Set 2) - Figure 20

Explanation

The athlete has a corneal abrasion. Fluorescein staining identifies the break in the epithelium when examined with ultraviolet light. Topical antibiotics are used as prophylaxis against secondary bacterial infection, and the patch, applied with the lid closed, is used for comfort and to promote epithelial healing. The accompanying symptoms, including pain, tearing, and photophobia, are usually too intense to allow a return to play. Surgery is reserved for a corneal laceration with associated loss of the anterior chamber. While a proper fundoscopic examination may be a consideration, increased intraocular pressure is not typically associated with this injury. Traumatic hemorrhage in the anterior chamber (hyphema) necessitates strict bed rest during the early phases of healing; examination will most likely reveal the red fluid level of blood settling inferiorly in the anterior chamber. It is often associated with increased intraocular pressure. Brucker AJ, Kozart DM, Nichols CW, et al: Diagnosis and management of injuries to the eye and orbit, in Torg JS (ed): Athletic Injuries to the Head, Neck, and Face. St Louis, MO, Mosby-Year Book, 1991, pp 650-670.

References:

Zagelbaum BM: Treating corneal abrasions and lacerations. Phys Sports Med 1997;25:38-44.

Question 87

A 46-year-old woman has bilateral groin pain, with more severe pain on the left side than on the right side. Figures 44a and 44b show a radiograph and a T1-weighted MRI scan. What is the most likely diagnosis?

Explanation

The radiograph reveals bilateral patchy sclerosis of the femoral heads without evidence of collapse. The MRI scan shows bilateral head involvement with a common serpentine-like low-intensity signal of the superior femoral head that is common to osteonecrosis. Changes confined to the femoral head effectively exclude rheumatoid arthritis and osteoarthritis. Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3160-3162.

References:

Epstein RE, Dalinka MK: Ischemic necrosis, in Stark DD, Bradley WG (eds): Magnetic Resonance Imaging, ed 3. St Louis, MO, Mosby, 1999, vol 2, pp 1023-1027.

Question 88

Figures 5a and 5b show the clinical photograph and radiograph of a patient who has difficulty wearing shoes and has persistent symptoms medially and laterally at the first and fifth metatarsophalangeal joints. Because shoe modifications have failed to provide relief, management should now consist of

Explanation

A significant bunionette deformity that fails to respond to conservative management is best addressed surgically, in this case with the bunion deformity. The radiograph reveals a prominent lateral condyle at the fifth metatarsal head without a significant increase in the intermetatarsal angle. Simple exostectomy is preferred with less risk of complications. Complete excision would risk transfer lesions to the medial metatarsals. Mann RA, Coughlin MJ: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 415-435.

References:

Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 163-173.

Question 89

A 22-year-old swimmer underwent thermal capsulorrhaphy treatment for recurrent anterior subluxation. Following 3 weeks in a sling, an accelerated rehabilitation program allowed him to return to swimming in 3 1/2 months. While practicing the butterfly stroke, he sustained an anterior dislocation. He now continues to have symptoms of anterior instability and has elected to have further surgery. Surgical findings may include a

Sports Medicine 2004 Practice Questions: Set 1 (Solved) - Figure 10

Explanation

Complications of thermal capsule shrinkage or accelerated rehabilitation include capsule ablation. Since the original surgery did not include labral reattachment, findings of a Bankart lesion or a glenoid fracture from a nontraumatic injury are unlikely. Subscapularis detachment or biceps subluxation is a postoperative complication of open repairs. Failure of early postoperative instability treatment should not produce loose bodies. Abrams JS: Thermal capsulorrhaphy for instability of the shoulder: Concerns and applications of the heat probe. Instr Course Lect 2001;50:29-36.

References:

Hecht P, Hayashi K, Lu Y, et al: Monopolar radiofrequency energy effects on joint capsular tissue: Potential treatment for joint instability. An in vivo mechanical, morphological, and biochemical study using an ovine model. Am J Sports Med 1999;27:761-771.

Question 90

A 6-year-old boy presents with a mass and a lucent lesion involving the tibial shaft as seen in Figure 17a. The mass is mildly tender to palpation. The bone scan is focally hot in the tibia. Biopsy specimens are shown in Figures 17b and 17c. What is the most likely diagnosis?

Explanation

Osteofibrous dysplasia frequently presents at a very young age, usually less than 10 years. In most patients, it involves the anterior cortex of the tibial shaft and minor anterior bowing of the tibia is frequently seen. The lesion is unpredictable in nature, but local recurrence is very high in patients who undergo surgery before 15 years of age. Campanacci M, Laus M: Osteofibrous dysplasia of the tibia and fibula. J Bone Joint Surg Am 1981;63:367-375.

References:

McCaffery M, Letts M, Carpenter B, et al: Osteofibrous dysplasia: A review of the literature and presentation of an additional 3 cases. Am J Orthop 2003;32:479-486.

Question 91

A 10-year-old boy has had wrist pain for the past 3 months. He denies any history of trauma. He reports mild tenderness associated with a palpable mass. A radiograph and biopsy specimens are shown in Figures 52a through 52c. What is the most likely diagnosis?

Explanation

The radiograph shows a benign-appearing cortically based lesion eroding the underlying cortex, producing a saucer-shaped defect typical of a periosteal chondroma. The histology shows benign-appearing neoplastic cartilage. Although enchondroma would have the same histologic appearance, radiographs generally show a lesion with a central medullary epicenter. The benign-appearing histology does not support chondrosarcoma. Chondromyxoid fibroma will generally show histologic elements of its fibrous and myxoid components. Chondroblastoma typically demonstrates histologic findings of polyhedral cells separated by a chondroid matrix with pericellular, lattice-like "chicken wire" calcification. Schajowicz F: Tumors and Tumorlike Lesions of Bone: Pathology, Radiology, and Treatment, ed 2. Berlin, Springer-Verlag, 1994, pp 147-151.

References:

Weiner SD: Enchondroma and chondrosarcoma of bone: Clinical, radiologic, and histologic differentiation. Instr Course Lect 2004;53:645-649.

Question 92

A 38-year-old man underwent a transtibial amputation for chronic posttraumatic foot and ankle pain and chronic calcaneal osteomyelitis. Postoperative radiographs are seen in Figures 41a and 41b. What is the proposed purpose of the surgical modification seen in the radiographs?

Explanation

The Ertl modification of a below-knee amputation has been proposed to create a more stable "platform" to aid in transferring the load of weight bearing between the residual limb and the prosthetic socket. It is felt that a stable platform allows total contact loading over an enlarged stable surface area. Early studies have suggested that this modification may enhance the patient's perceived functional outcome. Pinzur MS, Pinto MA, Saltzman M, et al: Health-related quality of life in patients with transtibial amputation and reconstruction with bone bridging of the distal tibia and fibula. Foot Ankle Int 2006;27:907-912.

References:

Pinzur MS, Pinto MA, Schon LC, et al: Controversies in amputation surgery. Instr Course Lect 2003;52:445-451.

Question 93

A 13-year-old girl was riding on an all-terrain vehicle when the driver struck a tree. She sustained the injury shown in Figures 45a through 45d. This injury is best described as what type of acetabular fracture pattern?

Explanation

The fracture is a both-column fracture in the Judet/Letournel classification and a C3 in the AO classification. There is extension into the sacroiliac joint along the pelvic brim and comminution along the posterior column above the sciatic notch. Both the anterior and posterior columns are separately broken and displaced. However, the defining feature of a both-column pattern, as seen in this patient, is that all articular fragments are on fracture fragments and no joint surface is left intact to the axial skeleton above. The use of three-dimensional images makes it easier to view the location of the fracture fragments and the amount and direction of displacement. Helfet DL, Beck M, Gautier E, et al: Surgical techniques for acetabular fractures, in Tile M, Helfet DL, Kellam JF (eds): Fractures of the Pelvis and Acetabulum. Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 533-603. Tile M: Describing the injury: Classification of acetabular fractures, in Tile M, Helfet DL, Kellam JF (eds): Fractures of the Pelvis and Acetabulum, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 427-475.

References:

Brandser E, Marsh JL: Acetabular fractures: Easier classification with a systematic approach. Am J Roentgenol 1998;171:1217-1228.

Question 94

When comparing the failure load of an evenly tensioned four-stranded hamstring tendon anterior cruciate ligament autograft to a 10-mm bone-patellar tendon-bone autograft, the hamstring graft will fail at a tension

Explanation

The failure load of an evenly tensioned four-stranded hamstring tendon autograft has been reported to be 4,500 Newtons. The failure load of a 10-mm patellar tendon autograft has been estimated at 2,600 Newtons. The intact anterior cruciate ligament failure load has been calculated at 1,725 Newtons. Corry IS, Webb JM, Clingeleffer AJ, Pinczewski LA: Arthroscopic reconstruction of the anterior cruciate ligament: A comparison of patellar tendon autograft and four-strand hamstring tendon autograft. Am J Sports Med 1999;27:448-454. Hamner DL, Brown CH Jr, Steiner ME, et al: Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: Biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-557.

References:

Noyes FR, Butler DL, Grood ES, et al: Biomechanical analysis of human ligament grafts used in knee-ligament repairs and reconstructions. J Bone Joint Surg Am 1984;66:344-352.

Question 95

What is the most likely cause of the lesion shown in Figures 35a and 35b?

Explanation

The most common cause of myositis ossificans is contusion. Certain regions, including the quadriceps and brachialis, are more commonly affected. The mechanisms of development have not been clearly established. Beiner JM, Jokl P: Muscle contusion injuries: Current treatment options. J Am Acad Orthop Surg 2001;9:227-237.

References:

Jarvinen TA, Jarvinen TL, Kaariainen M, et al: Muscle injuries: Biology and treatment. Am J Sports Med 2005;33:745-764.

Question 96

Which of the following is not a reported mode of failure for a constrained acetabular component?

Explanation

There is no evidence of increased polyethylene wear in constrained acetabular components. The rates of wear appear to be the same using standard or constrained liners. Lachiewicz PF, Kelley SS: Constrained components in total hip arthroplasty. J Am Acad Orthop Surg 2002;10:233-238. Anderson MJ, Murray WR, Skinner HB: Constrained acetabular components. J Arthroplasty 1994;9:17-23.

References:

Fisher DA, Kiley K: Constrained acetabular cup disassembly. J Arthroplasty 1994;9:325-329.

Question 97

Figure 37 shows the radiograph of a 23-year-old football player who sustained a blow to the anterior aspect of his shoulder. Examination reveals pain and limited rotation. He is unable to flex the arm above the shoulder. Management should include which of the following studies?

Sports Medicine Board Review 2001: High-Yield MCQs (Set 4) - Figure 4

Explanation

The patient has a posterior dislocation. The radiograph reveals marked internal rotation, but fails to show whether the humeral head is posteriorly displaced. Therefore, an axillary radiograph should be obtained to help confirm the diagnosis. Transverse view CT or MRI scans also may be useful. The other studies will not help confirm the diagnosis. In addition to a direct posterior blow, a shoulder dislocation may be caused by a seizure disorder or electrocution. Bloom MH, Obata WG: Diagnosis of posterior dislocation of the shoulder with the use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am 1967;49:943-949.

References:

Rockwood CA: Subluxations and dislocations about the shoulder, in Rockwood CA, Green DP (eds): Fractures in Adults, ed 2. Philadelphia, PA, JB Lippincott, 1984, vol 1, pp 806-856.

Question 98

A 47-year-old male tennis player has pain in his nondominant shoulder that has failed to respond to 4 months of nonsurgical management. Examination reveals acromial tenderness and pain at the supraspinatus tendon insertion. He has a positive impingement sign, pain on forward elevation, and minimal cuff weakness. The MRI scans are shown in Figures 30a and 30b. To completely resolve his symptoms, treatment should consist of

Explanation

The MRI scans show a mesoacromion with tendonopathy of the supraspinatus. The history and physical findings indicate that the patient has a symptomatic os acromiale. Simple excision of the unstable os acromiale has not yielded consistently good results. Meticulous internal fixation using tension banding with cannulated screws and autologous bone grafting has shown good results for this problem. Hutchinson MR, Veenstra MA: Arthroscopic decompression of shoulder impingement secondary to os acromiale. Arthroscopy 1993;9:28-32.

References:

Warner JJ, Beim GM, Higgins L: The treatment of symptomatic os acromiale. J Bone Joint Surg Am 1998;80:1320-1326.

Question 99

A 53-year-old man reports acute, severe left shoulder pain after undergoing abdominal surgery 10 days ago. Initial management, consisting of anti-inflammatory drugs, physical therapy, and a subacromial injection of corticosteroid, fails to provide relief. Reexamination of the shoulder 2 months after the onset of symptoms reveals atrophy of the infraspinous and supraspinous fossa and profound weakness of active abduction and external rotation. His neck is supple with a full range of motion. Plain radiographs and an MRI scan of the shoulder are normal. What diagnostic study should be performed next in the evaluation of this patient?

Explanation

Suprascapular nerve palsy is a fairly uncommon yet well-known cause of shoulder pain and weakness. A variety of causes have been described, including compression by a ganglion cyst, an anomalous or thickened superior transverse scapular ligament, a humeral and scapular fracture, and traction or kinking of the nerve in the suprascapular notch. In this patient, the injury is most likely caused by traction or compression of the nerve in the suprascapular notch as the result of positioning during abdominal surgery; therefore, the studies of choice are electromyography and nerve conduction velocity studies. While MRI of the cervical spine may be of some value in ruling out a radiculopathy, the clinical history does not support such a cause for this condition. Rengachary SS, Neff JP, Singer PA, Brackett CE: Suprascapular entrapment neuropathy: A clinical, anatomical, and comparative study. Part 1: Clinical study. Neurosurgery 1979;5:441-446. Rengachary SS, Burr D, Lucas S, Hassanein KM, Mohn MP, Matzke H: Suprascapular entrapment neuropathy: A clinical, anatomical and comparative study. Part 2: Anatomical study. Neurosurgery 1979;5:447-451.

References:

Bigliani LU, Dalsey RM, McCann PD, April EW: An anatomical study of the suprascapular nerve. Arthoscopy 1990;6:301-305.

Question 100

A 16-year-old girl has had hip pain for 1 year. Approximately 2 months ago she noted the development of a hard mass in the right buttock that has steadily increased in size. She now reports severe pain in the right buttock, with radiation down the leg and numbness involving the right foot and toes. A radiograph is shown in Figure 70a and an axial postcontrast T1-weighted MRI scan is shown in Figure 70b. A biopsy specimen is shown in Figure 70c. The chest CT shows multiple lung metastases. Treatment of this lesion should consist of

Explanation

Ewing's sarcoma is the second most common primary tumor of bone in children. Depending on the site and extent of disease, chemotherapy, radiation therapy, and surgery are all treatment options. In this patient with extensive pelvic and metastatic disease, chemotherapy and radiation therapy offer the best oncologic control while preserving functional outcome. Gibbs CP Jr, Weber K, Scarborough MT: Malignant bone tumors. Instr Course Lect 2002;51:413-428. Thacker MM, Temple HT, Scully SP: Current treatment for Ewing's sarcoma. Expert Rev Anticancer Ther 2005;5:319-331.

References:

Weber KL: Current concepts in the treatment of Ewing's sarcoma. Expert Rev Anticancer Ther 2002;2:687-694.

AAOS Orthopedic MCQs (Set 1): Spine Disorders, Sports Medicine & Arthroplasty | 2026 Board Review

100 Orthopedic MCQs: Trauma, Spine, Peds & Sports | ABOS & OITE Mock Exam Set 311

Key Takeaway

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Scientific References

Chapter Index