ABOS & OITE Orthopedic Mock Exam: 100 High-Yield MCQs

Question 1

Mutations of what gene are associated with subsequent development of osteosarcoma?

Explanation

The mutation of the retinoblastoma gene has been associated with an increased prevalence of osteosarcoma. The mutation resulting in EWS-FLI1 is associated with Ewing's sarcoma. The other mutations are associated with tumor formation and proliferation but not necessarily with osteosarcoma formation. Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 4. Scholz R, Kabisch H, Delling G, Winkler K: Homozygous deletion within the retinoblastoma gene in a native osteosarcoma specimen of a patient cured of a retinoblastoma of both eyes. Pediatr Hematol Oncol 1990;72:65.

References:

Hovig E, Lothe R, Farrants G, et al: Chromosome thirteen alterations in osteosarcoma cell lines derived from a patient with previous retinoblastoma. Cancer Genet Cytogenet 1991;57:31-40.

Question 2

Figure 8a shows the clinical photograph of an 83-year-old woman who has an enlarging left forearm mass. MRI scans are shown in Figures 8b and 8c. What is the next most appropriate step in management?

Explanation

Any large (greater than 5 cm), deep, heterogeneous mass in the extremities should be considered a sarcoma until proven otherwise. Sarcomas are rare, and without a high index of suspicion, the lesions may be misdiagnosed or there may be a delay in diagnosis. Needle biopsies can obtain sufficient tissue for diagnosis and are associated with less morbidity than open biopsy. Marginal resections or excisional biopsies should be reserved for a few select benign lesions and locations. Damron TA, Beauchamp CP, Rougraff BT, et al: Soft-tissue lumps and bumps. Instr Course Lect 2004;53:625-637.

References:

Sim FH, Frassica FJ, Frassica DA: Soft-tissue tumors: Diagnosis, evaluation, and management. J Am Acad Orthop Surg 1994;2:202-211.

Question 3

A collegiate football player who sustained an injury to his neck has significant neck pain and weakness in his extremities. Following immobilization, which of the following steps should be taken prior to transport?

Explanation

Prior to transport, the face mask should be removed so that the airway can be easily accessible. If serious injury is suspected, the helmet and shoulder pads should be left in place until he is assessed at the hospital and radiographs are obtained. Leaving the helmet and shoulder pads in place helps to keep the spine in the most neutral alignment. Removal of the helmet will result in extension of the neck, whereas removal of the shoulder pads will most likely result in flexion of the neck. Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 376. Thomas B, McCullen GM, Yuan HA: Cervical spine injuries in football players. J Am Acad Orthop Surg 1999;7:338-347. Waninger KN, Richards JG, Pan WT, et al: An evaluation of head movement in backboard-immobilized helmeted football, lacrosse, and ice hockey players. Clin J Sport Med 2001;11:82-86. Donaldson WF III, Lauerman WC, Heil B, et al: Helmet and shoulder pad removal from a player with suspected cervical spine injury: A cadaveric model. Spine 1998;23:1729-1732.

References:

Peris MD, Donaldson WF III, Towers J, et al: Helmet and shoulder pad removal in suspected cervical spine injury: Human control model. Spine 2002;27:995-998.

Question 4

Which of the following statements correctly describes the results of gamma irradiation of musculoskeletal allograft?

Explanation

Low dose gamma irradiation (less than 3.0 megarads) with antibiotic soaks is one of the most common techniques for secondary sterilization. Elimination of HIV with gamma irradiation requires doses estimated to be greater than 3.5 megarads. Gamma irradiation levels of 4 megarads have been shown to alter the mechanical properties of human infrapatellar tendons. Ethylene oxide, also used for allograft sterilization, has been associated with a chronic inflammatory process that resolved after graft removal. Jackson DW, Windler GE, Simon TM: Intraarticular reaction associated with the use of freeze-dried, ethylene oxide-sterilized bone-patella tendon-bone allografts in the reconstruction of the anterior cruciate ligament. Am J Sports Med 1990;18:1-10. Conway B, Tomford W, Mankin HJ, et al: Radiosensitivity of HIV-1: Potential application to sterilization of bone allografts. AIDS 1991;5:608-609.

References:

Rasmussen TJ, Feder SM, Butler DL, et al: The effects of 4 Mrad of gamma irradiation on the initial mechanical properties of bone-patellar tendon-bone grafts. Arthroscopy 1994;10:188-197.

Question 5

Arthrodesis of which of the following joints has the greatest cumulative effect on midfoot/hindfoot motion?

Explanation

Arthrodesis of the talonavicular joint eliminates almost all hindfoot motion. Arthrodesis of the subtalar joint eliminates 74% of talonavicular motion and 44% of calcaneocuboid motion. Arthrodesis of the calcaneocuboid joint eliminates 33% of talonavicular motion and 8% of subtalar motion. Arthrodesis of the naviculocuneiform or cuboid-fifth metatarsal joint has limited effect on hindfoot motion. Astion DJ, Deland JT, Otis JC, et al: Motion of the hindfoot after simulated arthrodesis. J Bone Joint Surg Am 1997;79:241-246.

References:

Savory KM, Wülker N, Stukenborg C, et al: Biomechanics of the hindfoot joints in response to degenerative hindfoot arthrodeses. Clin Biomech 1998;13:62-70.

Question 6

Which of the following accurately defines changes in Vitamin D requirements as the result of aging?

Explanation

Older individuals ingest less Vitamin D and are unable to generate as much as younger people via the skin in response to ultraviolet exposure; thus, there is a decrease in the levels of serum 25(OH) D. This reduction in 25(OH)D leads to a reduction in calcium absorption. There is also decreased conversion in the kidney of 25(OH)D to 1,25(OH)D. This all leads to an increase in the daily requirements of both calcium and Vitamin D. It also results in a responsive increase in PTH secretion in the elderly, as well as renal function impairment and possible renal resistance to PTH. Dawson-Hughes B, Harris SS, Krall EA, et al: Effect of calcium and vitamin D supplementation on bone density in men and women 65 years of age and older. N Engl J Med 1997;337:670-676. Recker RR, Hinders S, Davies M, et al: Correcting calcium nutritional deficiency prevents spine fractures in elderly women. J Bone Miner Res 1996;11:1961-1966.

References:

Rosen CJ, Kiel DP: The aging skeleton, in Favus, MJ (ed): Primer on Metabolic Bone Diseases and Disorders of Mineral Metabolism, ed 4. Philadelphia, PA, Lippincott Williams & Wilkins, 1999, pp 57-59.

Question 7

A 73-year-old man stepped off a street curb and felt a crack in his left hip. He is now unable to bear weight. A radiograph is shown in Figure 54a. Biopsy specimens are shown in Figures 54b and 54c. What is the most likely diagnosis?

Explanation

The biopsy specimens reveal a high-grade spindle cell lesion adjacent to an area of benign cartilage. This is consistent with a dedifferentiated chondrosarcoma. The radiograph shows a pathologic fracture through a lesion characterized by calcification within the left greater trochanter. Distal to the area of calcification, there is a more osteolytic, destructive appearance. Synovial sarcoma has a biphasic appearance histologically with areas of glandular differentiation that stain positive with keratin. Metastatic prostate cancer, although osteoblastic in appearance, would have a glandular histologic appearance. There is no cartilage in these lesions. Classic low-grade chondrosarcoma does not have an area of high-grade pleomorphic spindle cells within the lesion. A periosteal osteosarcoma is a surface-based lesion with a sunburst radiographic pattern. Although there may be cartilage in the lesion histologically, there are also malignant cells producing osteoid. Dedifferentiated chondrosarcoma is an aggressive, high-grade variant of chondrosarcoma. Wold LE, Adler CP, Sim FH, et al: Atlas of Orthopedic Pathology, ed 2. Philadelphia, PA, WB Saunders, 2003, p 269.

References:

Mercuri M, Picci P, Campanacci L, et al: Dedifferentiated chondrosarcoma. Skeletal Radiol 1995;24:409-416.

Question 8

Polyethylene wear of the bearing surface has been recognized as a mode of failure in total knee arthroplasty; therefore, many patients are offered polyethylene exchange. In terms of success rates, this surgical procedure has been reported to have a

Explanation

Engh and associates reported on the results of 63 knees (56 patients) following polyethylene exchange. The mean interval between exchange and the index total knee arthroplasty was 59 months. The mean follow-up after exchange was 7.4 years. Seven of 48 knees with adequate follow-up failed. Greater failure occurred if there was more severe wear before the exchange. Greater undersurface wear also resulted in a higher failure rate. Perioperative osteolysis or intraoperative observation of metallosis did not have an impact on the failure of polyethylene exchange. The risk of infection is no different from other total knee arthroplasty revisions. Wasielewski RC, Parks N, Williams I, et al: Tibial insert undersurface as a contributing source of polyethylene wear debris. Clin Orthop 1997;345:53-59.

References:

Engh GA, Koralewicz LM, Pereles TR: Clinical results of modular polyethylene insert exchange with retention of total knee arthroplasty components. J Bone Joint Surg Am 2000;82:516-523.

Question 9

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 10

There is increasing concern about the ethical relationship of orthopaedists to the orthopaedic equipment industry. Which of the following describes the most appropriate relationship?

Hip & Knee Reconstruction 2007 Practice Questions: Set 3 (Solved) - Figure 2

Explanation

It is appropriate for orthopaedic surgeons to have relationships with industry as long as the relationship is for the good of the patient and no "quid pro quo" intent exists. A grant to cover registration at a CME event is appropriate but travel and hotel for a spouse is not. For orthopaedists who are faculty at a meeting sponsored by industry, it is appropriate for travel and expenses to be covered for that faculty member. Care must be exercised that the faculty member contributes in an amount appropriate for the expenses paid. The faculty member must ensure that information presented is unbiased and based on reasonable data and opinion. Consulting agreements should spell out specifically the duties of the agreement and payment should be appropriate for the time spent. There should be a defined work product for the consulting. Agreements that are thinly veiled payments for use of a company's products must be avoided. In all cases, the agreements must stand up to public scrutiny. Restricted grants for specific industry-sponsored programs aimed at residents are not appropriate. Unrestricted grants intended for attendance at approved CME courses are appropriate. Dinners at which information is presented about topics that can aid in patient care are appropriate as long as the expense is reasonable ($100 or less/person) and the guest list includes individuals who can use the information in a patient case. Clearly a "premium" dinner for office staff to review new surgical instrumentation would not pass this test.

References:

Opinions on ethics and professionalism, in Guide to The Ethical Practice of Orthopaedic Surgery, ed 6. American Academy of Orthopaedic Surgeons, Rosemont, IL, 2006, pp 38-42.

Question 11

A 40-year-old man has a painless mass around his left ankle. He notes minimal growth over the past year. An MRI scan is shown in Figure 73a, and biopsy specimens are shown in Figures 73b and 73c. What is the most likely diagnosis?

Explanation

The biopsy specimen is a low-power view of a soft-tissue sarcoma with a biphasic pattern of epithelial cells and fibrous spindle cells that are typical of a synovial sarcoma. A deep, painless soft-tissue mass greater than 5 cm in size is suspicious for a sarcoma. The imaging in this patient is indeterminate and the patient requires a biopsy for an accurate diagnosis. The biopsy reveals a tumor with a biphasic appearance consistent with a synovial sarcoma. These tumors are slow growing, occur primarily in the lower extremities, and are found in a younger demographic population compared to malignant fibrous histiocytoma and liposarcoma. They can occur in a biphasic pattern with clumps of epithelial cells and fibrous spindle cells or in a monophasic pattern. Synovial sarcomas stain positively for keratin. Keratin is positive in nearly all biphasic types and in many tumors of the monophasic fibrous type. Sixty percent of these tumors are found in the lower extremity. The area around the knee is the most common location, followed by the ankle and foot. Epithelioid and clear cell sarcomas are found associated with tendon sheaths of the hand and feet and are generally smaller in size. Epithelioid sarcoma may resemble granulomatous inflammation histologically; clear cell sarcoma is composed of nests of clear cells with occasional multinucleated giant cells. Pigmented villonodular synovitis is found within the synovium and is characterized by a villous histologic appearance with hemosiderin-laden macrophages. Malignant fibrous histiocytoma has a storiform histologic pattern with an abundance of pleomorphic cells. Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3. St Louis, MO, Mosby, 1995, p 757.

References:

Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 227.

Question 12

Figure 2 shows the lateral radiograph of an 8-year-old boy who sustained an acute injury to the elbow after falling down the stairs. Management should consist of

Trauma 2000 Practice Questions: Set 1 (Solved) - Figure 4

Explanation

The patient has a flexion-type olecranon fracture, and the integrity of the extensor mechanism is disrupted. With this degree of displacement, closed reduction and extension casting would not be adequate. The strongest construct is an oblique screw across the fracture site, with a tension band. Healing is rapid in this age group; therefore one of the heavy absorbable sutures can be used as the tension band. Two parallel pins with the stainless steel tension band wire (AO technique) can be used but requires wire dissection for removal. Once the fracture is healed, the single screw can be removed easily with only a small incision. The presence of the screw, across the apophysis, has not been shown to produce any significant growth disturbance. Use of a large intramedullary screw would not be advisable because of the small size of the proximal fragment. Murphy DF, Greene WB, Gilbert JA, Dameron TB Jr: Displaced olecranon fractures in adults: Biomechanical analysis of fixation methods. Clin Orthop 1987;224:210-214.

References:

Chambers HG, Wilkins KE: Part IV: Fractures of the proximal radius and ulna, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 629-630.

Question 13

What patient factor is predictive of better outcomes for surgical management of a displaced calcaneal fracture compared to nonsurgical management?

Trauma 2006 Practice Questions: Set 1 (Solved) - Figure 33

Explanation

A recent randomized trial of surgical versus nonsurgical management of calcaneal fractures showed that patients who were on workers' compensation did poorly with surgical care. These patients had less favorable outcomes regardless of their initial management. Factors such as age, smoking, and vasculopathies compromise skin healing, leading to greater surgical risks. The best results were obtained in patients who are younger than age 40 years, have unilateral injuries and are injured during noncompensable activities. Women tend to do better with surgery than men. Howard JL, Buckley R, McCormack R, et al: Complications following management of displaced intra-articular calcaneal fractures: A prospective randomized trial comparing open reduction internal fixation with nonoperative management. J Orthop Trauma 2003;17:241-249.

References:

Buckley R, Tough S, McCormack R, et al: Operative compared with nonoperative treatment of displaced intra-articular calcaneal fractures: A prospective, randomized, controlled multicenter trial. J Bone Joint Surg Am 2002;84:1733-1744.

Question 14

A 50-year-old woman who underwent a joint replacement of the hallux metatarsophalangeal joint 6 months ago now has pain and swelling about the great toe. Radiographs are shown in Figures 39a and 39b. What is the next most appropriate step in management?

Explanation

The radiographs show displacement of the prosthesis, and there has been large amounts of bone resected to insert the implant. Arthrodesis is indicated with interposition bone graft to stabilize the joint and restore length to the first ray.

Scientific References

:

Myerson MS: Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 265-266.

Question 15

Figure 7 shows the CT scan of a 25-year-old soccer player who has had posterior ankle pain with plantar flexion for the past 2 years. Immobilization has failed to provide relief. He is ambulatory. Management should consist of

Foot & Ankle 2006 Practice Questions: Set 1 (Solved) - Figure 24

Explanation

An os trigonum is usually asymptomatic, but this accessory bone has been associated with persistent posterior ankle pain, which has been described as os trigonum syndrome. This usually affects athletes and ballerinas. Forced plantar flexion leads to impingement of the os trigonum against the posterior tibial plafond, and flexor hallucis tendinitis may develop. It may be difficult to differentiate a fractured trigonal process from the os trigonum. MRI may reveal bone marrow edema that may aid in the diagnosis of os trigonum syndrome. Steroid injections may lead to tendon rupture. The results of excision of a symptomatic os trigonum through a posteromedial or lateral approach are favorable, with a rapid return to full function. The main complication of this procedure is sural nerve injury with a lateral approach. Hedrick MR, McBryde AM: Posterior ankle impingement. Foot Ankle Int 1994;15:2-8.

References:

Abramowitz Y, Wollstein R, Barzilay Y, et al: Outcome of resection of a symptomatic os trigonum. J Bone Joint Surg Am 2003;85:1051-1057.

Question 16

What are the two terminal branches of the lateral cord of the brachial plexus?

Explanation

The lateral cord divides into the musculocutaneous and median nerves. The posterior cord terminates into the axillary and radial nerves. The medial cord divides into the ulnar and median nerves. Hollinshead WH: Anatomy for Surgeons, ed 3. Philadelphia, PA, Harper and Row, 1982, pp 228-236.

References:

Shin AY, Spinner RJ, Steinmann SP, et al: Adult traumatic brachial plexus injuries. J Am Acad Orthop Surg 2005;13:382-396.

Question 17

Which of the following findings is a contraindication to isolated percutaneous pinning of a distal radius fracture?

Explanation

Intrafocal pinning allows the Kirschner wires to be placed through a site of comminution and then drilled through intact cortex. Generally Kapandji intrafocal pinning is done for dorsal comminuted extra-articular dorsal bending fractures, but it also may be used to elevate and buttress radial comminution. Simple intra-articular fractures can also be treated with pinning alone. Intrafocal pinning works best as a dorsal or radial buttress to prevent shortening. When there is volar comminution, the fracture is prone to shortening and supplemental external fixation or plating is recommended. Trumble TE, Wagner W, Hanel DP, et al: Intrafocal (Kapandji) pinning of distal radius fractures with and without external fixation. J Hand Surg Am 1998;23:381-394. Choi KY, Chan WS, Lam TP, et al: Percutaneous Kirschner-wire pinning for severely displaced distal radial fractures in children: A report of 157 cases. J Bone Joint Surg Br 1995;77:797-801.

References:

Weil WM, Trumble TE: Treatment of distal radius fractures with intrafocal (Kapandji) pinning and supplemental skeletal stabilization. Hand Clin 2005;21:317-328.

Question 18

Figures 21a and 21b show the radiographs of a 12-year-old patient with an L4-level myelomeningocele who has scoliosis that has been slowly progressing for the past several years. There has been no loss of motor function. An MRI scan shows no syringomyelia or increased hydrocephalus. Management should consist of

Explanation

Scoliosis is a common occurrence in children with myelomeningocele, with the incidence increasing as the neurologic level moves cephalad. The rate of pseudarthrosis for isolated anterior or posterior fusions has been reported as high as 75%. The combination of anterior and posterior fusions with some type of instrumentation has been shown to decrease the rate of pseudarthrosis to 20%. Brace treatment in smaller curves can be used as a temporizing measure to delay surgery, but as with idiopathic scoliosis, the brace is ineffective for larger curves. Observation is not indicated with a curve of this magnitude. Ward WT, Wenger DR, Roach JW: Surgical correction of myelomeningocele scoliosis: A critical appraisal of various spinal instrumentation systems. J Pediatr Orthop 1989;9:262-268.

References:

Muller EB, Nordwall A: Brace treatment of scoliosis in children with myelomeningocele. Spine 1994;19:151-155.

Question 19

A 52-year-old woman slipped on ice in her driveway. Radiographs are shown in Figures 19a and 19b. The patient was treated in a short leg cast with weight bearing as tolerated for 6 weeks. Due to persistent tenderness at the fracture site, a CAM walker was used for an additional 8 weeks. Nine months after the injury, the patient still walks with a limp and reports pain with deep palpation at the fracture site. What is the next most appropriate step in management?

Explanation

Persistent pain at the fracture site in the absence of infection is most likely due to a nonunion, best detected by CT. Walsh and DiGiovanni reported on a series of closed rotational fibular fractures in which nonunions were detected by CT in the absence of standard ankle radiographic findings. Repeat immobilization would not be appropriate at this late date. Pain management/sympathetic blocks would be considered if the patient displayed pain with light touch and disproportionate pain consistent with a complex mediated pain syndrome. Acupuncture would be expected to be of limited benefit. Walsh EF, DiGiovanni C: Fibular nonunion after closed rotational ankle fracture. Foot Ankle Int 2004;25:488-495.

References:

Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2003, pp 182-183.

Question 20

Figure 35 shows the lateral radiograph of a 15-year-old basketball player who felt a dramatic pop in his knee when landing after a lay-up. The patient reports that he cannot bear weight on the injured extremity. Management should consist of

Sports Medicine Board Review 2001: High-Yield MCQs (Set 4) - Figure 2

Explanation

Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted. Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.

References:

Pape JM, Goulet JA, Hensinger RN: Compartment syndrome complicating tibial tubercle avulsion. Clin Orthop 1993;295:201-204.

Question 21

Management of a grade IV osteochondritis dissecans lesion of the capitellum should consist of

Explanation

Osteochondritis dissecans of the capitellum is seen most commonly in adolescent athletes. It should be distinguished from osteochondrosis of the capitellum (Panner's disease), a self-limiting condition seen in younger patients. Lesions are graded I through V based on radiographic and arthroscopic appearance. Grade I lesions show intact but soft cartilage. Grade II lesions show fissuring of the overlying cartilage. Grade III lesions show exposed bone or an attached osteoarticular flap that is not loose. Grade IV lesions show a loose but nondisplaced osteoarticular flap. Grade V lesions show a displaced fragment. Simple excision of the loose osteoarticular flap is the treatment of choice for grade IV and V lesions. More complex procedures such as drilling of the in situ lesion, bone grafting, or internal fixation are associated with significantly worse results. While some authors advocate abrasion chondroplasty, the long-term benefits of the procedure are yet to be proven. Baumgarten TE: Osteochondritis dissecans of the capitellum. Sports Med Arthroscopy Rev 1995;3:219-223.

References:

Shaughnessy WJ, Bianco AJ: Osteochondritis dissecans, in Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, pp 282-287.

Question 22

What are the most likely symptoms and examination findings related to the mass in zone 2 of Guyon's canal seen in Figure 17?

Upper Extremity Board Review 2008: High-Yield MCQs (Set 2) - Figure 11

Explanation

The lesion lies in zone II of the ulnar tunnel. In that zone the deep motor branch of the ulnar nerve is susceptible to compression. Distal to the hook of the hamate, the motor branch of the ulnar nerve dives deep to innervate the interossei as it begins to move from an ulnar to radial direction. Because of its course, it has little or no give in response to a mass effect from the floor of Guyon's canal. Ganglions are the most common cause of ulnar nerve entrapment in the wrist. Lesions in zone I can affect both sensory and motor aspects of the ulnar nerve as well as the motor innervation of the hypothenar muscles. Lesions at the elbow or mid-to-proximal forearm are associated with dorsal hand numbness and tingling. Kuschner SH, Gelberman RH, Jennings C: Ulnar nerve compression at the wrist. J Hand Surg Am 1988;13:577-580.

References:

Posner MA: Compressive neuropathies of the ulnar nerve at the elbow and wrist. Instr Course Lect 2000;49:305-317.

Question 23

A 32-year-old man sustained a fracture of his upper arm in a motor vehicle accident. Radiographs are shown in Figure 32. Because of other associated injuries, surgical stabilization is chosen. What technique will result in the least complications and the best outcome?

Trauma 2006 Practice Questions: Set 3 (Solved) - Figure 10

Explanation

Most humeral fractures will heal with nonsurgical functional brace management. When the initial pain has subsided in a coaptation splint, the patient is converted to a functional brace and allowed to use the arm for activities. The fracture should heal within 6 weeks to 12 weeks with acceptable results. Surgery is indicated if there is vascular injury, open injury, floating elbow, chest injury, bilateral humeral fractures, or if a reduction cannot be obtained or maintained. The surgical treatment of choice is either antegrade reamed locked intramedullary nailing or plate osteosynthesis. Plate osteosynthesis appears to offer better results with respect to union, function, and risk of complications. Schemitsch EH, Bhandari M: Fractures of the humeral shaft, in Browner BD: Skeletal Trauma, ed 3. Philadelphia, PA, WB Saunders, 2003, pp 1481-1511.

References:

Chapman JR, Henley MB, Agel J: Randomized prospective study of humeral shaft fracture fixation: Intramedullary nails versus plates. J Orthop Trauma 2000;14:162-166.

Question 24

A 39-year-old man has anterior shoulder pain after landing on his abducted left shoulder while playing softball. Examination reveals a stable glenohumeral joint, pain on passive external rotation of greater than 25 degrees, and pain and weakness on belly press (Napoleon's) test. An MRI scan is shown in Figure 32. To provide maximum pain relief and return of function, management should include

Sports Medicine Board Review 2004: High-Yield MCQs (Set 4) - Figure 1

Explanation

The examination and MRI scan confirm a subscapularis rupture and dislocation of the long head of the biceps tendon. The greatest return of function will result from repair of the subscapularis and tenodesis of the biceps tendon. Physical therapy alone will result in inadequate healing of the subscapularis and will not address the biceps tendon. While biceps tenotomy is an option, it will not provide the same level of pain relief and return of function as a tenodesis in a young, active man. There is no evidence for a supraspinatus tear. Deutsch A, Altchek DW, Veltri DM, Potter HG, Warren RF: Traumatic tears of the subscapularis tendon: Clinical diagnosis, magnetic resonance imaging findings, and operative treatment. Am J Sports Med 1997;25:13-22.

References:

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

Question 25

During a posterior approach to the right Achilles tendon, the surgeon encounters a nerve running with the small saphenous vein as shown in Figure 22. This nerve innervates what part of the foot?

Foot & Ankle Board Review 2009: High-Yield MCQs (Set 2) - Figure 26

Explanation

The sural nerve runs with the small saphenous vein on the posterior leg just lateral to the Achilles tendon. It is formed by contributions from both the tibial and common peroneal nerves and provides sensation on the dorso-lateral aspect of the foot. Aktan Ikiz ZA, Ucerler H, Bilge O: The anatomic features of the sural nerve with an emphasis on its clinical importance. Foot Ankle Int 2005;26:560-567.

References:

Lawrence SJ, Botte MJ: The sural nerve in the foot and ankle: An anatomic study with clinical and surgical implications. Foot Ankle Int 1994;15:490-494.

Question 26

What is the most important factor in determining recovery after surgical repair of a complete laceration of a nerve at the wrist?

Explanation

All other factors being equal, a patient's age is the most important factor in determining outcome after peripheral nerve injury. Repair of a nerve laceration within the first 2 weeks is generally considered appropriate. Fascicular repair may be of benefit in larger proximal nerves to reapproximate appropriate nerve bundles; distally perineural or epineural repair is sufficient. Use of a fibrin tissue sealant for nerve repair does not result in improved outcomes over suture repair. Nerve conduits have shown promise in digital nerves but do not have proven benefit in larger caliber nerves. Sunderland S: Nerve Injuries and Their Repair: A Critical Appraisal. New York, NY, Churchill Livingstone, 1991. Wilgis ES, Brushart TM: Nerve repair and grafting, in Green DP, Hotchkiss RN (eds): Operative Hand Surgery, ed 3. New York, NY, Churchill Livingstone, 1993, p 1325. Narakas A: The use of fibrin glue in repair of peripheral nerves. Orthop Clin North Am 1988;19:187-199.

References:

Weber RA, Breidenbach WC, Brown RE, et al: A randomized prospective study of polyglycolic acid conduits for digital nerve reconstruction in humans. Plast Reconstr Surg 2000;106:1036-1045.

Question 27

After stabilizing a bimalleolar ankle fracture with a plate and lag screws for the fibula and two interfragmental compression screws for the medial malleolus, a syndesmosis screw is indicated in which of the following situations?

Trauma Board Review 2000: High-Yield MCQs (Set 2) - Figure 22

Explanation

It is imperative to recognize the need for a position screw (syndesmosis screw) to hold the syndesmosis in proper alignment when surgically stabilizing an ankle fracture. Although many different fracture patterns are suspicious for a disrupted syndesmosis, the only sure way to assess the syndesmosis is to stress it with abduction and external rotation of the talus and attempt to displace the fibula from the incisura fibularis. Under fluoroscopy, the talus will move laterally and displace the fibula, show a valgus talar tilt, or show an increase in the medial clear space. If any or all of these signs occur, a syndesmosis screw is inserted after making sure that the fibula is reduced into the incisura fibularis. This screw may traverse three or four cortices but must not act as a lag screw. It usually is inserted with the ankle in maximal dorsiflexion, although this is probably not necessary because it is almost impossible to overcompress the syndesmosis. The diameter of the screw does not make any difference. It may or may not be removed but not before 3 months. Tornetta P III, Spoo JE, Reynolds FA, Lee C: Overtightening of the ankle syndesmosis: Is it really possible? J Bone Joint Surg Am 2001;83:489-492. Stover MD, Kellam JF: Articular fractures: Principles, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 105-119. Hahn DM, Colton CL: Malleolar fractures, in Ruedi TP, Murphy WM (eds): AO Principles of Fracture Management. Stuttgart, Thieme, 2000, pp 559-581.

References:

Tile M: Fractures of the ankle, in Schatzker J, Tile M (eds): Rationale of Operative Fracture Care, ed 2. Berlin, Springer-Verlag, 1998, pp 523-561.

Question 28

What cell type causes the bone destruction in metastatic lesions?

Explanation

The main consequence of tumor invading the bone is activation of both osteoblasts and osteoclasts. However, the osteoclastic effect predominates in the majority of tumors early after the invasion of bone by tumor cells, causing resorption of bone. Cramer SF, Fried L, Carter KJ: The cellular basis of metastatic bone disease in patients with lung cancer. Cancer 1981;48:2649-2660.

References:

Clohisy DR, Palkert D, Ramnaraine ML, Pekurovsky I, Oursler MJ: Human breast cancer induces osteoclast activation and increases the number of osteoclasts at sites of tumor osteolysis. J Orthop Res 1996;14:396-402.

Question 29

An otherwise healthy 25-year-old man sustained a wound with a 1-cm by 1.5-cm soft-tissue loss over the volar aspect of the middle phalanx of his middle finger. After appropriate debridement and irrigation, the flexor digitorum profundus tendon and neurovascular bundles are visible. The wound should be treated with a

Trauma 2006 Practice Questions: Set 1 (Solved) - Figure 16

Explanation

The wound described indicates loss of soft tissue directly to the level of the tendon, precluding use of skin grafts if excursion of the tendon is desired. A cross-finger flap is ideal for small wounds on the volar aspect of digits. A thenar flap is suitable for tip injuries. A lateral arm flap will not reach the fingers. A Moberg flap is limited to distal injuries of the thumb. Kappel DA, Burech JG: The cross-finger flap: An established reconstructive procedure. Hand Clin 1985;1:677-683.

References:

Lister GD: Skin flaps, in Green DP, Hotchkiss RN (eds): Operative Hand Surgery, ed 3. New York, NY, Churchill Livingstone, 1993, p 1741.

Question 30

A 9-year-old boy has pain over the midfoot medially with activity. Based on the findings shown in Figures 26a and 26b, which of the following is considered the most effective short-term management?

Explanation

While Kohler's disease has a benign course, temporary cast immobilization has been shown to result in a shortened duration of symptoms. Core decompression or other surgery is not warranted because of the benign nature. Shoe inserts may be beneficial, but there are no studies to support their use. Borges JL, Guile JT, Bowen JR: Kohler's bone disease of the tarsal navicular. J Pediatr Orthop 1995;15:596-598.

References:

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

Question 31

Second impact syndrome (SIS) after head injury is characterized by which of the following?

Explanation

SIS is a devastating but preventable complication of head injury. It occurs when return to activities is allowed prior to complete resolution of the symptoms of the first head injury. A second, sometimes trivial, head injury can lead to a devastating series of events that can result in sudden death. The symptoms tend to progress rapidly and often involve the brain stem. The prognosis is poor. Cantu RC: Second-impact syndrome. Clin Sports Med 1998;17:37-44. Saunders RL, Harbaugh RE: Second impact in catastrophic contact-sports head trauma. JAMA 1984;252:538-539.

References:

Stevenson KL, Adelson PD: Pediatric sports-related head injuries, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 1, p 781.

Question 32

A 13-year-old girl with Down syndrome has bilateral chronic patellar dislocations. She denies knee pain. She is able to straighten her knees and walks with a symmetric but awkward gait. She does not flex her knees in midstance. Examination reveals that the patellae cannot be brought into a reduced position. Management should consist of

Pediatrics Board Review 2004: High-Yield MCQs (Set 2) - Figure 15

Explanation

Chronic dislocation of the patella is occasionally seen in patients with Down syndrome. In early childhood, patellar realignment may restore stability of the patellae. In later childhood, bony changes in the patellar groove interfere with stability, even if surgical realignment is performed. Realignment can also lead to increased knee pain postoperatively. In asymptomatic patients who are able to extend their knees, continued observation is the management of choice. Dugdale TW, Renshaw TS: Instability of the patellofemoral joint in Down syndrome. J Bone Joint Surg Am 1986;68:405-413.

References:

Mendez AA, Keret D, MacEwen GD: Treatment of patellofemoral instability in Down's syndrome. Clin Orthop 1988;234:148-158.

Question 33

Figures 21a through 21c show the radiographs of a 70-year-old woman who has persistent pain with activity after undergoing hip revision 6 months ago. Treatment should now consist of

Explanation

The radiographs show disruption of the posterior column of the acetabulum with radiolucencies about the component. Because the patient requires a stable construct to allow the bone to heal, the treatment of choice is an antiprotrusio cage and a graft. Gill TJ, Sledge JB, Muller ME: The Burch-Schneider anti-protrusio cage in revision total hip arthroplasty: Indications, principles, and long-term results. J Bone Joint Surg Br 1998;80:946-953.

References:

Sharkey PF, Hozack WJ, Callaghan JJ, et al: Acetabular fracture associated with cementless acetabular component insertion: A report of 13 cases. J Arthroplasty 1999;14:426-431.

Question 34

A 62-year-old patient with rheumatoid arthritis has had pain and instability of the elbow following total elbow replacement 2 years ago. A complete work-up, including aspiration and cultures, is negative. Figures 9a and 9b show the AP and lateral radiographs. Treatment should consist of

Explanation

The patient has aseptic loosening of the original semiconstrained prosthesis and significant proximal ulnar bone destruction; therefore, the treatment of choice is revision arthroplasty using a semiconstrained design. Although orthotic stabilization could be used, it will not provide long-term pain relief. Resection arthroplasty after removal of the components may lead to painful instability. Elbow arthrodesis would be difficult with the bone stock loss and is not considered the best option. Two main contraindications to the use of an unconstrained prosthesis are significant bone loss and previous use of a hinged or semiconstrained prosthesis. An ulnar allograft could be combined with the use of a semiconstrained long-stemmed ulnar prosthesis as a treatment modification. Ewald FC, Simmons ED Jr, Sullivan JA, et al: Capitellocondylar total elbow replacement in rheumatoid arthritis: Long-term results. J Bone Joint Surg Am 1993;75:498-507.

References:

Morrey BF, King GJ: Revision of failed total elbow arthroplasty, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 602-610.

Question 35

A 52-year-old woman has bicompartmental osteoarthritis following patellectomy. Treatment should consist of

Explanation

The patient has extensive degenerative changes in both the medial and lateral compartments within the knee; therefore, arthroscopic debridement or an osteotomy will not be helpful. A patellar arthroplasty will not address the medial and lateral compartments. Because the extensor mechanism provides a significant amount of anteroposterior stability, a posterior cruciate-substituting total knee arthroplasty is the treatment of choice for this patient. Martin SD, Haas SB, Insall JN: Primary total knee arthroplasty after patellectomy. J Bone Joint Surg Am 1995;77:1323-1330.

References:

Pagnano MW, Cushner FD, Scott WN: Role of the posterior cruciate ligament in total knee arthroplasty. J Am Acad Orthop Surg 1998;6:176-187.

Question 36

An open biopsy specimen of a radiodense distal clavicle lesion in a 12-year-old girl shows chronic polyclonal inflammatory cells without granuloma formation. Laboratory studies show that bacterial, fungal, and acid-fast bacillus cultures are negative. Subsequently, a similar lesion is noted in the fibula. The next most appropriate step in management should consist of

Explanation

The most likely diagnosis is chronic multifocal osteomyelitis. This is a culture-negative polyostotic disease that is most commonly found in young people. The treatment of choice is anti-inflammatory drugs. The pathology does not suggest eosinophilic granuloma. Antiviral therapy, broad-spectrum antibiotics, and surgical resection are not indicated for this disease.

References:

Carr AJ, Cole WG, Roberton DM, Chow CW: Chronic multifocal osteomyelitis. J Bone Joint Surg Br 1993;75:582-591.

Question 37

What is the most common presenting sign or symptom in an adult with lumbar pyogenic infection?

Explanation

Pain is very common but is often nonspecific; therefore, the diagnosis of spinal infection is often delayed. Fever and sepsis can occur but are not common. Neurologic manifestations also can occur but are absent in most patients. In findings reported by Carragee, the urinary tract is a common source for hematogenous spinal infection, but the source was found in only 27% of 111 patients. Direct inoculation during spinal surgery is uncommon. Carragee EJ: Pyogenic vertebral osteomyelitis. J Bone Joint Surg Am 1997;79:874-880. Frazier DD, Campbell DR, Garvey TA, et al: Fungal infections of the spine: Report of eleven patients with long-term follow-up. J Bone Joint Surg Am 2001;83:560-565.

References:

Hadjipavlou AG, Mader JT, Necessary JT, et al: Hematogenous pyogenic spinal infections and their surgical management. Spine 2000;25:1668-1679.

Question 38

Figure 11 shows the radiograph of a 2-year-old child with marked genu varum and tibial bowing. Based on these findings, what is the best initial course of action?

Pediatrics 2007 Practice Questions: Set 1 (Solved) - Figure 27

Explanation

The radiograph shows multiple wide physes, consistent with a diagnosis of rickets. A low serum phosphorous level and an elevated alkaline phosphatase level are the hallmarks in diagnosing familial hypophosphatemic Vitamin D-resistant rickets. Serum calcium is usually normal or low normal. This disease is inherited as an X-linked dominant trait and usually presents at age 18 to 24 months. The disease results from a poorly defined problem with renal phosphate transport in which normal dietary intake of vitamin D is insufficient to achieve normal bone mineralization. Renal tubular dysfunction is associated with urinary phosphate wasting. Treatment involves oral phosphate supplementation, which can cause hypocalcemia and secondary hyperparathyroidism. To prevent associated problems, high doses of Vitamin D are administered. While obtaining a scanogram may be clinically indicated in an associated limb-length discrepancy, and subsequent corrective surgery may be indicated, either of these choices would not be the first course of action. An orthosis may slow the progression of genu varum in this disorder but is less important than establishing the correct diagnosis to begin pharmacologic treatment. This amount of varum and tibial bowing far exceeds the normal limits of physiologic genu varum. Skeletal dysplasias usually are not associated with abnormal laboratory values. Herring JA: Metabolic and endocrine bone diseases, in Tachdjian's Pediatric Orthopaedics, ed 3. New York, NY, WB Saunders, 2002, pp 1685-1743.

References:

Sillence DO: Disorders of bone density, volume, and mineralization, in Rimoin DL, Conner JM, Pyerite RE, et al (eds): Principles and Practice of Medical Genetics, ed 3. New York, NY, Churchill Livingstone, 1995, pp 1996-2002.

Question 39

Staphylococcus aureus develops methicillin resistance through production of which of the following agents?

Explanation

Organisms may develop resistance to antibiotics by production of specific enzymes. S aureus develops methicillin resistance by production of penicillin-binding protein 2a (PBP2a). The strains of S aureus that have acquired the mecA gene for PBP2a are designated as methicillin-resistant S aureus (MRSA). The enzyme manifests resistance to covalent modification by beta-lactam antibiotics at the active-site serine residue in two ways. First, the microscopic rate constant for acylation (k2) is attenuated by three to four orders of magnitude over the corresponding determinations for penicillin-sensitive PBPs. Second, the enzyme shows elevated dissociation constants (Kd) for the noncovalent preacylation complexes with the antibiotics, the formation of which ultimately would lead to enzyme acylation. The two factors working in concert effectively prevent enzyme acylation by the antibiotics in vivo, giving rise to drug resistance. Catalase and oxidase are enzymes produced by some bacteria that confer virulence to the organism but do not make the organisms methicillin resistant. Glycocalix is the pericellular layer produced by bacteria that serves many functions including attachment to surfaces. Beta-lactam describes a class of antibiotics. Fuda C, Suvorov M, Vakulenko SB, et al: The basis for resistance to beta-lactam antibiotics by penicillin-binding protein 2a (PBP2a) of methicillin-resistant staphylococcus aureus. J Biol Chem 2004;279:40802-40806. Lim D, Strynadka NC: Structural basis for the beta lactam resistance of PBP2a from methicillin-resistant Staphylococcus aureus. Nat Struct Biol 2002;9:870-876.

References:

Schwarz EM: Infections in orthopaedics, 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 40

Figures 5a and 5b show the radiograph and MRI scan of a patient who has severe mechanical neck pain but no neurologic problems. Biopsy and work-up show the lesion to be a solitary plasmacytoma. Treatment should consist of

Explanation

Plasmacytoma is very sensitive to radiation therapy and given the complexity of the resection and complications of surgery in the given location, radiation therapy is preferred. However, the patient has clear loss of bony structural integrity, and resultant instability would persist even with tumor irradiation; therefore, posterior stabilization is warranted. Chemotherapy and bone marrow transplant are reserved for systemic disease with multiple myeloma. Corwin J, Lindberg RD: Solitary plasmacytoma of bone vs. extramedullary plasmacytoma and their relationship to multiple myeloma. Cancer 1979;43:1007-1013.

References:

Durr HR, Wegener B, Krodel A, et al: Multiple myeloma: Surgery of the spine. Retrospective analysis of 27 patients. Spine 2002;27:320-324.

Question 41

A 21-year-old collegiate track athlete increased her training 4 months ago in anticipation of starting the season. Two months into her training program, she reported pain followed by a 1-month history of diffuse pain in the first metatarsophalangeal joint that was aggravated by weight bearing. A removable walker boot partially relieved the pain, and she was able to complete the season. Her pain has now returned; however, she denies any history of injury. Examination reveals tenderness over the medial sesamoid but no deformities. A radiograph and bone scan are shown in Figures 22a and 22b. What is the best treatment option at this time?

Explanation

The radiograph reveals either a fractured or bipartite sesamoid. The bone scan shows asymmetrically increased uptake over the medial sesamoid. Given the history and physical examination, a stress fracture is the most likely diagnosis. Medial sesamoidectomy reliably improves pain, and athletes return to sports on an average of 7 weeks after excision. Immobilization typically requires more than 4 to 8 weeks and is not always successful; however, it would be appropriate management for a patient who is not an elite athlete. Sanders R: Fractures of the midfoot and forefoot, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1601-1603.

References:

Saxena A, Krisdakumtorn T: Return to activity after sesamoidectomy in athletically active individuals. Foot Ankle Int 2003;24:415-419.

Question 42

A patient undergoes excision of a 3- x 3-cm soft-tissue sarcoma. The final histology results show tumor at the surgical margin. The surgical procedure performed is classified as

Explanation

Surgical margins are classified according to the plane of dissection in relation to the tumor. An intralesional procedure is where the plane of dissection passes through the tumor. A marginal resection involves a resection where the plane of dissection is through the reactive zone of the tumor. A wide resection is through completely normal tissue outside of the reactive zone. A radical resection removes all of the muscles and/or bone of the compartment that are involved by the tumor.

References:

Enneking WF, Spanier SS, Goodman MA: A system for the surgical staging of musculoskeletal sarcoma. Clin Orthop 1980;153:106-120.

Question 43

Which of the following statements about injury of the anterior vascular structures during lumbar disk surgery is true?

Explanation

Vascular injury most commonly occurs at L4-L5, followed by L5-S1 and are associated with use of the pituitary rongeur. Hohf reported that 17 of 58 patients died as a result. Early recognition and treatment of this complication is vital; unfortunately, intraoperative bleeding from the disk space may occur in up to 50% of these patients. Some may be first recognized in the recovery room. Common clinical findings include hypotension, tachycardia, and a rigid abdomen. Formation of an arteriovenous fistula is the most common vascular injury resulting from lumbar disk surgery but is usually not recognized until months after surgery. Cardiomegaly and high output cardiac failure are common presenting symptoms. Hohf RP: Arterial injuries occurring during orthopaedic operations. Clin Orthop 1963;28:21-37. Montorsi W, Ghiringhelli C: Genesis, diagnosis and treatment of vascular complications after intervertebral disk surgery. Int Surg 1973;58:233-235.

References:

Stambough JL, Simeone FA: Vascular complications in spine surgery, in Garfin SR (ed): Complications of Spine Surgery. Baltimore, MD, Williams and Wilkins, 1989, pp 323-341.

Question 44

Steroids are thought to prevent neurologic deterioration after traumatic spinal cord injury by which of the following mechanisms?

Explanation

The proposed mechanisms by which steroids such as methylprednisolone are thought to prevent neurologic deterioration by limiting secondary insult, include: decreasing the area of ischemia in the cord, reducing TNF-alpha expression and NF-kB binding activity, decreasing free radical oxidation and thus stabilizing cell and lysosomal membranes, and checking the influx of calcium into the injured cells, thus reducing cord edema. Slucky AV: Pathomechanics of spinal cord injury. Spine: State Art Rev 1999;13:409-417.

References:

Torg JS, Thibault L, Sennett B, et al: The Nicolas Andry Award. The pathomechanics and pathophysiology of cervical spinal cord injury. Clin Orthop Relat Res 1995;321:259-269.

Question 45

A 40-year-old woman with no history of back problems has a symptomatic L4-5 disk herniation with an L5 radiculopathy that has failed to respond to 12 weeks of nonsurgical management. In the preoperative discussion, the surgeon advises the patient that the chance of recurrence of the herniation after successful diskectomy is what percent?

Explanation

The incidence of recurrent disk herniation after a successful diskectomy is approximately 5% to 10%. Indications for surgical diskectomy for a recurrence are the same as for a primary diskectomy. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 685-698.

References:

Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 127-139.

Question 46

A 21-year-old woman who was wearing a seat belt sustained an injury of the thoracolumbar junction in a motor vehicle accident. The AP radiograph shows widening between the L1 and L2 spinous processes, and the CT scan shows the empty facet sign at this level. The initial evaluation should include

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

Explanation

The patient has a flexion-distraction injury of the thoracolumbar spine that is often associated with wearing a seat belt. The fracture has a high risk of associated intra-abdominal injury; therefore, the initial evaluation should include a CT of the abdomen. The most common visceral injury is to the bowel. Smith WS, Kaufer H: Patterns and mechanisms of lumbar injuries associated with lap seat belts. J Bone Joint Surg Am 1969;51:239-254.

Scientific References

:

LeGay D, Petrie DP, Alexander DI: Flexion-distraction injuries of the lumbar spine and associated abdominal trauma. J Trauma 1990;30:436-444.

Question 47

Commotio cordis is best treated with

Sports Medicine 2007 Practice Questions: Set 1 (Solved) - Figure 12

Explanation

Commotio cordis is a rare but catastrophic condition that is caused by blunt chest trauma. It results in cardiac fibrillation and is universally fatal unless immediate defibrillation is performed. Although case reports of successful use of the chest thump maneuver exist, the best method of treatment is cardiac defibrillation. IV fluids, epinephrine, and albuterol inhalers are used to treat dehydration, anaphylactic shock, and bronchospasm respectively, and are not effective in the treatment of commotio cordis. McCrory P: Commotio cordis. Br J Sports Med 2002;36:236-237.

References:

Boden BP, Tacchetti R, Mueller FO: Catastrophic injuries in high school and college baseball players. Am J Sports Med 2004;32:1189-1196.

Question 48

A 24-year-old athlete has a painful right shoulder. Figure 30 shows an intra-articular photograph that was obtained through a posterior portal during arthroscopy; the labrum is indicated by the arrow. Based on these findings, management should consist of

Shoulder 2002 Practice Questions: Set 3 (Solved) - Figure 5

Explanation

The photograph shows a normal variant that is a sublabral hole beneath the anterosuperior labrum. In some instances, the labrum will become confluent with the middle glenohumeral ligament as a stout band. Because this variant is not abnormal, no treatment is necessary. Securing this portion of the labrum to the capsule may tighten the middle glenohumeral ligament complex and restrict external rotation of the arm. Andrews JR, Guerra JJ, Fox GM: Normal and pathologic arthroscopic anatomy of the shoulder, in Andrews JR, Timmerman LA (eds): Diagnostic and Operative Arthroscopy, ed 1. Philadelphia, PA, WB Saunders, 1997, pp 60-76.

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 49

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 50

A 17-year-old football player is injured during a play and reports abdominal pain that is soon followed by nausea and vomiting. What organ has most likely been injured?

Sports Medicine 2007 Practice Questions: Set 1 (Solved) - Figure 28

Explanation

The spleen is the most common organ injured in the abdomen as the result of blunt trauma. It is also the most common cause of death because of an abdominal injury. The liver is the second most commonly injured organ. Injury to the other organs is rare. The diagnosis can be made with CT. Treatment ranges from observation to splenectomy, depending on the severity of injury. Green GA: Gastrointestinal disorders in the athlete. Clin Sports Med 1992;11:453-470.

References:

Kibler WB (ed): ACSM's Handbook for Team Physician. Philadelphia, PA, Williams & Wilkins, 1996, p 151.

Question 51

Figures 15a through 15c show the radiographs of a 23-year-old football player who was injured when another player fell on his flexed and planted foot. He reports severe pain in the midfoot with a feeling of numbness on the dorsum of the foot, and he is unable to bear weight on the limb. Examination reveals mild swelling. Management should consist of

Explanation

Myerson and associates studied the outcomes of 19 patients with tarsometatarsal joint injuries during athletic activity. Injuries were classified as first- or second-degree sprains of the tarsometatarsal joint or a third-degree sprain with diastasis between the metatarsals or cuneiforms. Poor functional results were seen in those with a delay in diagnosis and with inadequate treatment. For patients with third-degree sprains, poor results were obtained with nonsurgical management. These patients required open reduction and internal fixation for optimal return to function. The anatomic reduction is critical to the outcome; therefore, open reduction is preferred. Baxter DE: The Foot and Ankle in Sport, ed 1. St Louis, MO, Mosby, 1995, pp 107-123. Curtis MJ, Myerson M, Szura B: Tarsometatarsal joint injuries in the athlete. Am J Sports Med 1993;21:497-502. Kuo RS, Tejwani NC, DiGiovanni CW, et al: Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am 2000;82:1609-1618.

References:

Thompson MC, Mormino MA: Injury to the tarsometatarsal joint complex. J Am Acad Orthop Surg 2003;11:260-267.

Question 52

Antibiotic-loaded bone cement prostheses, such as that shown in Figure 8, are best created by using which of the following methods?

Hip & Knee Reconstruction 2007 Practice Questions: Set 1 (Solved) - Figure 17

Explanation

In a review of the practical applications of antibiotic-loaded bone cement for the treatment of the infected total joint arthroplasties, Hanssen and Spangehl described commercially available antibiotic-loaded bone cement as low-dose antibiotic cements. These cements generally contained 0.5 g of either tobramycin or gentamicin per 40 g of cement. They are indicated for use in prophylaxis and not for treatment of infected total joint arthroplasties. High-dose antibiotic-loaded bone cements are described as those containing greater than 1.0 g of antibiotic per 40 g of cement. Effective elution levels have been documented with 3.6 g tobramycin and 1.0 g vancomycin per 40 g of bone cement. This was documented by Penner and associates. Furthermore, it was shown that the combination of the two antibiotics in the bone cement improved the elution of both antibiotics. Hanssen AD, Spangehl MJ: Practical applications of antibiotic-loaded bone cement for treatment of infected joint replacements. Clin Orthop 2004;427:79-85.

References:

Penner MJ, Masri BA, Duncan CP: Elution characteristics of vancomycin and tobramycin combined in acrylic bone-cement. J Arthroplasty 1996;11:939-944.

Question 53

Figure 15 shows the radiograph of an active 60-year-old woman. Which of the following variables is considered the strongest contraindication to a unicompartmental knee arthroplasty in this patient?

Hip & Knee Reconstruction Board Review 2007: High-Yield MCQs (Set 2) - Figure 2

Explanation

Unicompartmental arthroplasty of the knee for single compartment arthrosis has recently become more popular. Contraindications to unicompartmental knee arthroplasty include fixed varus or valgus deformity of more than 5 degrees, restricted range of motion, fixed flexion contracture, joint subluxation of 5 mm or greater, and arthrosis of the opposite and/or patellofemoral compartment. Cossey AJ, Spriggins AJ: The use of computer-assisted surgical navigation to prevent malalignment in unicompartmental knee arthroplasty. J Arthroplasty 2005;20:29-34. Iorio R, Healy WL: Unicompartmental arthritis of the knee. J Bone Joint Surg Am 2003;85:1351-1364.

References:

Argenson JN, Chevrol-Benkeddache Y, Aubaniac JM: Modern unicompartmental knee arthroplasty with cement: A three to ten-year follow-up study. J Bone Joint Surg Am 2002;84:2235-2239.

Question 54

Which of the following treatments of polyethylene results in the highest amount of oxidative degradation?

Explanation

Oxidative degradation of polyethylene occurs as a function of time in an air environment. In an environment such as argon, nitrogen, or a vacuum, the process is reduced. Ethylene oxide is an alternative for sterilization in which the cross-link degradation is minimized because of the absence of oxidative interactions. Gamma sterilization or use of ethylene oxide gas is the industry standard; however, oxygen concentrations are now reduced to a minimal level to retard the oxidation phenomenon. Sanford WM, Saum KA: Accelerated oxidative aging testing of UHMWPE. Trans Orthop Res Soc 1995;20:119. Sun DC, Schmidig G. Stark C, et al: On the origins of a subsurface oxidation maximum and its relationship to the performance of UHMWPE implants. Trans Soc Biomater 1995;18:362. Callaghan JJ, Dennis DA, Paprosky WA, Rosenberg AG (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, pp 35-41.

References:

McKellup HA: Bearing surfaces in total hip replacement: State of the art and future developments. Instr Course Lect 2001;50:165-179.

Question 55

The humeral nonunion shown in Figure 27 is most likely to unite when using what method of treatment?

Trauma 2006 Practice Questions: Set 3 (Solved) - Figure 2

Explanation

The radiograph shows an atrophic nonunion of the humeral shaft. The management of humeral nonunions has been studied with compression plates and bone graft, as well as intramedullary nailing and bone graft. Compression plating with bone graft results in the highest rate of union. Compression plating by itself is not adequate, given the bone loss and lack of callous in this nonunion. Pulsed electromagnetic fields is a viable option for hypertrophic nonunions where there is inherent stability. Intramedullary nailing does not provide as much compression and stability as that achieved with compression plating. Pugh DM, McKee MD: Advances in the management of humeral nonunion. J Am Acad Orthop Surg 2003;11:48-59.

References:

McKee MD, Miranda MA, Riemer BL, et al: Management of humeral nonunion after the failure of locking intramedullary nails. J Orthop Trauma 1996;10:492-499.

Question 56

What structure is located immediately posterior to the capsule at the posterior cruciate ligament tibial insertion?

Explanation

The popliteal artery lies just posterior to the posterior cruciate ligament tibial insertion, separated only by the posterior capsule of the knee. When performing a posterior cruciate ligament reconstruction, this artery is at risk for injury during creation of the tibial tunnel. Jackson DW, Proctor CS, Simon TM: Arthroscopic assisted PCL reconstruction: A technical note on potential neurovascular injury related to drill bit configuration. J Arthroscopy 1993;9:224-227.

References:

Malek MM, Fanelli GC: Technique of arthroscopically assisted PCL reconstruction. Orthopedics 1993;16:961-966.

Question 57

An active 48-year-old woman has had progressive retrocalcaneal pain for the past 2 years. She reports that an injection into the retrocalcaneal bursa 3 weeks ago provided relief, but she now has swelling and weakness after tripping on the stairs 3 days ago. The Thompson test is positive. A radiograph is shown in Figure 36. What is the next most appropriate step in management?

Foot & Ankle 2000 Practice Questions: Set 3 (Solved) - Figure 16

Explanation

The patient's long-standing symptoms and radiograph indicate a chronic insertional Achilles tendinopathy that has progressed to complete rupture. This situation is best treated with tendon debridement and repair, often requiring supplementation graft from the flexor hallucis longus. MRI could provide additional information on the quality of the Achilles tendon, but neither MRI nor ultrasound is necessary to make a diagnosis or determine the surgical indication. Conservative management will be unpredictable with a chronic degenerative tendon injury. Myerson MS, McGarvey W: Disorders of the Achilles tendon: Insertion and Achilles tendinitis. Instr Course Lect 1999;48:211-218. Wilcox DK, Bohay DR, Anderson JG: Treatment of chronic Achilles tendon disorders with flexor hallucis longus tendon transfer/augmentation. Foot Ankle Int 2000;21:1004-1010.

References:

Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 253-277.

Question 58

A 15-year-old high school soccer player collides with an opponent and is unconscious when the trainer arrives on the field. He is conscious within 15 seconds, breathing appropriately, and denies any headache, neck pain, or nausea. It is his first head injury. Provided that the athlete is free of symptoms, when should he be allowed to return to athletic activity?

Sports Medicine 2007 Practice Questions: Set 1 (Solved) - Figure 29

Explanation

The loss of consciousness indicates a grade 2 concussion, which necessitates a 4-week period out of sport. The last week prior to return must be symptom-free and the athlete should not have symptoms in practice. Cantu RC: Return to play guidelines after a head injury. Clin Sports Med 1998;17:45-60.

References:

Stevenson KL, Adelson PD: Pediatric sports-related head injuries, in Delee JC, Drez D (eds): Orthopaedic Sports Medicine, ed 2. Philadelphia, PA, WB Saunders, 2003, vol 1, p 781.

Question 59

What is the most appropriate treatment for a 50-year-old woman who sustains the injury shown in Figures 14a and 14b?

Explanation

This intra-articular distal humerus fracture with displacement at the joint surface is best treated with surgical fixation. The most biomechanically sound construct is two plates applied to either column 180 degrees from one another. Elbow arthroplasty is most appropriate for low demand elderly patients. Schemitsch EH, Tencer AF, Henley MB: Biomechanical evaluation of methods of internal fixation of the distal humerus. J Orthop Trauma 1994;8:468-475. McCarty LP, Ring D, Jupiter JB: Management of distal humerus fractures. Am J Orthop 2005;34:430-438.

References:

Kamineni S, Morrey BF: Distal humeral fractures treated with noncustom total elbow replacement: Surgical technique. J Bone Joint Surg Am 2005;87:41-50.

Question 60

The gluteus maximus is innervated by which of the following nerves?

Anatomy 2002 Practice Questions: Set 1 (Solved) - Figure 20

Explanation

The inferior gluteal nerve supplies the gluteus maximus muscle. The superior gluteal nerve supplies the gluteus medius, gluteus minimus, and tensor fascia lata muscles. The femoral nerve supplies the quadriceps, sartorius, and pectineus muscles. The pudendal nerve is primarily a sensory nerve.

References:

Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, pp 146-147.

Question 61

What percent of patients initially diagnosed with classic, high-grade osteosarcoma of the extremity have visible evidence of pulmonary metastasis on CT of the chest?

Basic Science 2006 Practice Questions: Set 1 (Solved) - Figure 9

Explanation

CT studies show that approximately 10% to 20% of patients with high-grade osteosarcoma have pulmonary metastases at diagnosis. Although not visible on current staging studies, it is believed that up to 80% of patients have micrometastatic disease that requires systemic chemotherapy. Because it is not possible to identify those patients who do not have disseminated micrometastatic disease, most patients are treated presumptively with chemotherapy. Kaste SC, Pratt CB, Cain AM, et al: Metastases detected at the time of diagnosis of primary pediatric extremity osteosarcoma at diagnosis: Imaging features. Cancer 1999;86:1602-1608.

References:

Link MP, Goorin AM, Miser AW, et al: The effect of adjuvant chemotherapy on relapse-free survival in patients with osteosarcoma of the extremity. N Engl J Med 1986;314:1600-1606.

Question 62

What is the most appropriate next step in the work-up of a patient with the asymptomatic lesion shown in Figure 23?

Basic Science Board Review 2002: High-Yield MCQs (Set 2) - Figure 40

Explanation

The eccentric metaphyseal location, skeletal maturity, narrow zone of transition, and lack of symptoms suggest a benign process and are consistent with a healed nonossifying fibroma. These lesions typically fill in (ossify) with skeletal maturity, eventually remodeling and disappearing. Radiographic monitoring is indicated. Biopsy is not recommended unless the lesion changes radiographically. Marks KE, Bauer TW: Fibrous tumors of bone. Orthop Clin North Am 1989;20:377-393. Bullough PG, Walley J: Fibrous cortical defect and non-ossifying fibroma. Postgrad Med J 1965;41:672-676.

References:

Skrede O: Non-osteogenic fibroma of bone. Acta Orthop Scand 1970;41:362-380.

Question 63

In patients without spondylolisthesis or scoliosis undergoing laminectomy for lumbar spinal stenosis, spinal fusion is generally recommended if

Explanation

With the notable exception of fusion for degenerative spondylolisthesis and scoliosis, there is a paucity of evidence on the indications for spinal fusion in patients undergoing laminectomy for spinal stenosis. However, it is generally recommended that if the spine is destabilized (for example by removal of one complete facet joint or by an iatrogenic pars fracture), spinal fusion should be considered. Although fusion can be considered for a very long laminectomy, a two-level laminectomy does not represent, by itself, a clear indication for the addition of a spinal fusion. The repair of a dural tear and the use of nicotine by the patient play no role in the determination of whether or not to add fusion to a laminectomy procedure. Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 299-409.

References:

Fischgrund JS, Mackay M, Herkowitz HN, et al: 1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: A prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation. Spine 1997;22:2807-2812.

Question 64

A 74-year-old woman with rheumatoid arthritis reports shoulder pain that has failed to respond to nonsurgical management. AP and axillary radiographs are shown in Figures 23a and 23b. Examination reveals active forward elevation to 120 degrees and external rotation to 30 degrees. What treatment option results in the most predictable pain relief and function?

Explanation

Most studies have shown that total shoulder arthroplasties yield better pain relief and improved forward elevation when compared to hemiarthroplasty in patients with rheumatoid arthritis. Although rotator cuff tears are more common in this patient population, this patient has good forward elevation and no significant superior migration of the humeral head; therefore, a reverse arthroplasty is not indicated. The arthritis is too advanced in this patient to consider arthroscopy, but in less advanced cases it can improve range of motion and decrease pain. Metal-backed glenoid components have shown higher rates of loosening. Collin DN, Harryman DT II, Wirth MA: Shoulder arthroplasty for the treatment of inflammatory arthritis. J Bone Joint Surg Am 2004;86:2489-2496. Baumgarten KM, Lashgari CM, Yamaguchi K: Glenoid resurfacing in shoulder arthroplasty: Indications and contraindications. Instr Course Lect 2004;53:3-11.

References:

Martin SD, Zurakowski D, Thornhill TS: Uncemented glenoid component in total shoulder arthroplasty: Survivorship and outcomes. J Bone Joint Surg Am 2005;87:1284-1292.

Question 65

Figure 12 shows the lumbar CT scan of a 24-year-old man who was injured in a snowmobile accident. What is the mechanism of injury?

Spine Surgery Board Review 2000: High-Yield MCQs (Set 2) - Figure 5

Explanation

A true compression fracture is a single-column injury that does not create canal compromise. A burst fracture is a two- or three-column injury that disrupts the middle column and thereby narrows the spinal canal. This patient has a burst fracture. The mechanism of injury is usually vertical compression or flexion compression. Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.

References:

Spivak JM, Vaccaro AR, Cotler JM: Thoracolumbar spine trauma: Principles of management. J Am Acad Orthop Surg 1995;3:353-360.

Question 66

A 13-year-old girl has had right groin pain for the past 3 weeks. She denies any history of trauma. Examination of the hip reveals no palpable soft-tissue mass or lymphadenopathy, and there is full range of motion. A plain radiograph and MRI scan are shown in Figures 15a and 15b. Biopsy specimens are shown in Figures 15c and 15d. What is the most likely diagnosis?

Explanation

Fibrous dysplasia frequently occurs in the proximal femur. Microfractures and remodeling can lead to the classic "Shepherd's crook deformity." The lesion has a ground-glass appearance on plain radiographs. The histologic appearance shows proliferating fibroblasts in a loose spindle cell background. Dysplastic metaplastic trabeculae are arranged in an irregular or "Chinese letter" appearance. Enneking WF, Gearen PF: Fibrous dysplasia of the femoral neck: Treatment by cortical bone grafting. J Bone Joint Surg Am 1986;68:1415-1422.

References:

Simon MA, Springfield DS, et al: Common Benign Bone Tumors: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 194-200.

Question 67

A 21-year-old man has had progressive right knee pain for the past 2 months that is exacerbated with weight-bearing activities. A plain radiograph and an MRI scan are shown in Figures 43a and 43b. A biopsy specimen is shown in Figure 43c. According to the Enneking staging system of tumor classification, the lesion should be classified as what stage?

Explanation

The lesion is an eccentric lytic bone lesion within the epiphyseal-metaphyseal end of the proximal tibia. There is geographic destruction with a "fading border" extending to the articular cartilage. There is no matrix formation or periosteal reaction. The MRI scan shows cortical destruction with extension into the soft tissue. According to the Enneking staging system, benign lesions are stage 1, 2, or 3; malignant lesions are stage I, II, or III. Benign stage 1 lesions are latent; stage 2 are active; and stage 3 are benign aggressive. The histology shows a benign giant cell tumor. Given the cortical breakthrough shown on the MRI scan, the lesion should be classified as stage 3. Enneking WF: Clinical musculoskeletal pathology, in Enneking WF (ed): Appendix A. Gainesville, FL, Storter Publishing, 1986, pp 451-466.

References:

Aboulafia AJ, Kennon RE, Jelinek JS: Benign bone tumors of childhood. J Am Acad Orthop Surg 1999;7:377-388.

Question 68

A distal radius fracture in an elderly man is strongly predictive for what subsequent injury?

Trauma Board Review 2006: High-Yield MCQs (Set 2) - Figure 31

Explanation

Fractures of the distal radius increase the relative risk of a subsequent hip fracture significantly more in men than in women. A previous spinal fracture has an equally important impact on the risk of a subsequent hip fracture in both genders.

References:

Haentjens P, Autier P, Collins J, et al: Colles fracture, spine fracture, and subsequent risk of hip fracture in men and women: A meta-analysis. J Bone Joint Surg Am 2003;85:1936-1943.

Question 69

What malignant disease most commonly develops in conjunction with chronic osteomyelitis?

Basic Science Board Review 2005: High-Yield MCQs (Set 2) - Figure 15

Explanation

The most common malignant disease to arise in conjunction with chronic osteomyelitis is squamous cell carcinoma particularly in patients with a long-standing draining sinus tract. Dell PC: Hand, in Simon MA, Springfield D (eds): Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott-Raven, 1998, pp 405-420.

References:

McGrory JE, Pritchard DJ, Unni KK, Ilstrup D, Rowland CM: Malignant lesion arising in chronic osteomyelitis. Clin Orthop 1998;362:181-189.

Question 70

After humeral head replacement for four-part fractures, what is the most commonly reported difficulty?

Shoulder 2002 Practice Questions: Set 1 (Solved) - Figure 25

Explanation

Results show that patients who underwent humeral head replacement for fracture almost routinely report pain relief, but functional reports vary. The most commonly reported difficulty is the use of weight in the overhead position with wide variation in active elevation. Factors found to affect active elevation include age, humeral offset, greater tuberosity positioning, and four-part (as compared with three-part) fractures. Goldman RT, Koval KJ, Cuomo F, Gallagher MA, Zuckerman JD: Functional outcome after humeral head replacement for acute three- and fourth-part proximal humeral fractures. J Shoulder Elbow Surg 1995;4:81-86.

References:

Hawkins RJ, Switlyk P: Acute prosthetic replacement for severe fractures of the proximal humerus. Clin Orthop 1993;289:156-160.

Question 71

Figures 38a and 38b show the CT scans of a 64-year-old woman. What is the most likely diagnosis?

Explanation

The CT scans show large cystic lesions in the talus and calcaneus with complete subluxation of the subtalar joint, allowing the calcaneus to slide laterally until it becomes blocked by the fibula. The cause of this subluxation is severe posterior tibial tendon dysfunction. Although no fibular fracture has yet appeared, it can occur with continued stress from the calcaneus. There is, however, a pathologic fracture in the medial calcaneus through a medial degenerative cyst. The joint space is irregular and not symmetrical as would be seen in an inflammatory arthropathy. Cystic lesions are not present in the tibia. No stress fracture is seen in the talus. Coughlin MJ: Sesamoids and accessory bones of the foot, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 437-499.

References:

Anderson RB, Davis WH: Management of the adult flatfoot deformity, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 1017-1039.

Question 72

A 22-year-old right hand-dominant man who fell off his motorcycle onto the tip of his right shoulder 2 weeks ago now reports pain and difficulty raising his right arm. Examination reveals tenderness and gross movement over the lateral scapular spine and severe weakness during resisted abduction. A radiograph and 3D-CT scan are shown in Figures 24a and 24b. What is the next most appropriate step in management?

Explanation

The patient has a displaced scapular spine fracture that has resulted in shoulder weakness from a poor deltoid lever arm. The downward tilt may lead to subacromial impingement and rotator cuff dysfunction. Open reduction and internal fixation would best allow normal deltoid and shoulder function. Bone stimulators and abduction bracing may lead to healing but in a malunited position. Arthroscopic acromioplasty and fragment excision should be avoided. Ogawa K, Naniwa T: Fractures of the acromion and the lateral scapular spine. J Shoulder Elbow Surg 1997;6:544-548.

Scientific References

:

Ada Jr, Miller ME: Scapular fractures: Analysis of 113 cases. Clin Orthop Relat Res 1991;269:174-180.

Question 73

A sentinel event is defined as an unexpected occurrence involving death or serious physical or psychological injury, or the risk thereof. What is the most common sentinel event related to spine surgery?

Explanation

Patient safety and prevention of medical errors is a major focus of recent national advocacy groups. Analysis has shown that the most common sentinel event in spine surgery is surgery on the wrong level. Therefore, it is recommended that every patient have the surgical site signed, the level of surgery marked intraoperatively, and a radiograph taken. Surgery on the wrong level is most likely to occur in single-level decompressive procedures. Wong DA, Watters WC III: To err is human: Quality and safety issues in spine care. Spine 2007;32:S2-S8.

References:

Wong DA: Spinal surgery and patient safety: A systems approach. J Am Acad Orthop Surg 2006;14:226-232.

Question 74

What structure provides the most static stability for valgus restraint in the elbow?

Explanation

The anterior band of the ulnar collateral ligament provides the greatest restraint to valgus stress in the elbow. The posterior band is taut in flexion and resists stress between 60 degrees and full flexion. The annular ligament stabilizes the radial head. The flexor/pronator mass are important dynamic stabilizers of the medial elbow. Ahmad CS, ElAttrache NS: Elbow valgus instability in the throwing athlete. J Am Acad Orthop Surg 2006;14:693-700. Regan WD, Korinek SL, Morrey BF, et al: Biomechanical study of ligaments around the elbow joint. Clin Orthop Relat Res 1991;271:170-179.

References:

Safran M, Ahmad CS, ElAttrache NS: Ulnar collateral ligament of the elbow. Arthroscopy 2005;21:1381-1395.

Question 75

A study is being designed to compare the effectiveness of an antibiotic. The choice of the number of patients (ie, the sample size) depends on several factors. What type of calculation assesses the potential of the study to successfully address the effectiveness of the antibiotic?

Explanation

Power analysis is used to determine the minimum number of specimens (sample size) such that, if a difference is found that is large enough to be clinically important, the associated level of statistical reliability will be high enough (ie, the P-value will be small enough) for the investigators to conclude that the difference observed in the study also holds in general. For the statistician to do a power analysis, the investigators must first decide on the minimum difference that they consider to be clinically important, for example, a reduction of 3% in the rate of infection. It is important to recognize that the choice of what constitutes the minimum difference in the rate of infection that is clinically (ie, medically) important cannot and should not be done by the statistician. Rather, this is a clinical-medical issue and must be done by the physician researcher based on a comprehensive assessment of the medical risks and benefits. The power analysis also requires an estimate of the variance in the data, which may be based on previous similar studies, if available. A statistician can then calculate the minimum sample size (number of patients) required such that, if a clinically important difference does, in fact, exist between the full populations, there is a reasonable probability or power (typically 80% to 90%) that a difference this large also will occur between the sample populations at the desired level of statistical significance (usually, but not necessarily, P < 0.05). The other answers refer to types of analyses that are usually conducted after the data are collected.

References:

Ebramzadeh E, McKellop H, Dorey F, et al: Challenging the validity of conclusions based on P-values alone: A critique of contemporary clinical research design and methods. Instr Course Lect 1994;43:587-600.

Question 76

A 35-year-old woman who is training for a triathlon has had a 2-month history of heel pain with weight bearing and is unable to run. History reveals that she is amenorrheic. Examination reveals that she is thin and has pain over the heel that is exacerbated with medial and lateral compression. Range of motion and motor and sensory function are normal. Radiographs are normal. What is the most likely diagnosis?

Foot & Ankle 2000 Practice Questions: Set 1 (Solved) - Figure 29

Explanation

The most likely diagnosis is a stress fracture of the calcaneus and is supported by the history of running, female gender, and amenorrhea. Reproducing pain with medial and lateral compression of the heel also supports the diagnosis. A bone scan or MRI would most likely confirm the diagnosis. Plantar fasciitis would result in pain on the bottom of the heel with point tenderness. The lack of other areas of involvement or other symptoms does not support a seronegative inflammatory arthritis. Tarsal tunnel syndrome and peripheral neuropathy are unlikely because of the normal neurologic examination. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 597-612.

References:

Lutter LD, Mizel MS, Pfeffer GB (eds): Orthopaedic Knowledge Update: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 179-191.

Question 77

Which of the following nutraceuticals has been associated with perioperative bleeding?

Hip & Knee Reconstruction 2007 Practice Questions: Set 1 (Solved) - Figure 11

Explanation

Ginkgo biloba is a popular nutraceutical for patients who have early dementia, intermittent claudication secondary to peripheral vascular disease, vertigo, and tinnitus. It is reported to improve mental alertness and cognitive deficiency. It has antiplatelet properties as a result of one of its components, ginkgolide B, which displaces platelet-activating factor from its receptor binding sight. Rowin and Lewis reported on spontaneous bilateral subdural hematomas associated with chronic ginkgo biloba ingestion. Vale also reported on subarachnoid hemorrhage associated with ginkgo biloba. Bebbington and associates reported on persistent postoperative bleeding after total hip arthroplasty secondary to ginkgo biloba usage. Furthermore, the use of ginkgo biloba with aspirin or other antiplatelet agents or anticoagulants represents a relative contraindication. Physicians should be aware not only of prescribed medications but also alternative nutraceuticals that are used by the patient. Rowin J, Lewis SL: Spontaneous bilateral subdural hematomas associated with chronic ginkgo biloba ingestion. Neurology 1996;46:1775-1776. Vale S: Subarachnoid hemorrhage associated with ginkgo biloba. Lancet 1998;352:36.

References:

Bebbington A, Kulkarni R, Roberts P: Ginkgo biloba: Persistent bleeding after total hip arthroplasty caused by herbal self-medication. J Arthroplasty 2005;20:125-126.

Question 78

Figure 19 shows an arthroscopic view from the anterior lateral portal of the knee looking into the suprapatella pouch. The use of an electrothermal device during this procedure most commonly causes significant postoperative complications by damaging which of the following structures?

Anatomy Board Review 2002: High-Yield MCQs (Set 2) - Figure 11

Explanation

While it is possible to damage any of these structures, unrecognized intraoperative laceration without adequate coagulation of the superior lateral geniculate artery is common. This can result in significant postoperative hemarthrosis and a return to surgery when bleeding cannot be controlled. Cash JD, Hughston JC: Treatment of acute patella dislocation. Am J Sports Med 1988;16:244-249.

References:

Henry R, Goletz B, Williamson C: Lateral release in patello-femoral subluxation. Am J Sports Med 1986;14:121.

Question 79

An 18-month-old boy with obstetric brachial plexus palsy is being evaluated for limited right shoulder motion. Physical therapy for the past 6 months has failed to result in improvement of the contracture. Which of the following studies is necessary prior to any shoulder reconstruction?

Pediatrics 2007 Practice Questions: Set 1 (Solved) - Figure 12

Explanation

The child sustained a brachial plexus injury at birth, and internal rotation/adduction contractures frequently develop at the shoulder. Initial treatment should consist of physical therapy to increase the range of motion. If this fails, as in this patient, MRI is used to evaluate the glenohumeral joint. Commonly, there is joint deformity with increased retroversion of the glenoid and even posterior shoulder subluxation. If the deformity is mild, an anterior release, coupled with teres major and latissimus transfers, is very effective. If the deformity is severe and the shoulder is unreconstructable, then humeral derotation osteotomy is the procedure of choice. MRI of the brain, a radiograph of the elbow, and aspiration of the shoulder would not be helpful. Waters PM: Update on management of pediatric brachial plexus palsy. J Pediatr Orthop B 2005;14:233-244. Waters PM, Bae DS: Effect of tendon transfers and extra-articular soft-tissue balancing on glenohumeral development in brachial plexus birth palsy. J Bone Joint Surg Am 2005;87:320-325.

References:

Moukoko D, Ezaki M, Wilkes D, et al: Posterior shoulder dislocation in infants with neonatal brachial plexus palsy. J Bone Joint Surg Am 2004;86:787-793.

Question 80

A 10-year-old child reports acute leg pain after wrestling with his brother. AP and lateral radiographs are shown in Figures 21a and 21b. What is the best course of action?

Explanation

The radiographs show an eccentric metaphyseal lesion with a well-defined reactive rim of bone that is consistent with a nonossifying fibroma. Pathologic fractures through benign lesions should be treated as appropriate for the fracture, allowing the fracture to heal. Biopsy is not needed when the radiographic diagnosis is benign. MRI, in the presence of a fracture, is not particularly helpful because of the hematoma. If radiographic findings reveal that the lesion appears aggressive, a biopsy should be performed, obtaining tissue away from the fracture site. Marks KE, Bauer TW: Fibrous tumors of bone. Orthop Clin North Am 1989;20:377.

References:

Ponseti IV, Friedman B: Evaluation of metaphyseal fibrous defects. J Bone Joint Surg Am 1949;31:582.

Question 81

Posterior sternoclavicular dislocations are most commonly associated with which of the following complications?

Anatomy 2002 Practice Questions: Set 1 (Solved) - Figure 6

Explanation

Posterior sternoclavicular dislocations are commonly associated with tracheal compression, which can be a life-threatening condition requiring immediate reduction. The other listed complications are less common. Brooks AL, Henning GD: Injury to the proximal clavicular epiphysis, abstracted. J Bone Joint Surg Am 1972;54:1347-1348.

References:

Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 255-260.

Question 82

A 60-year-old woman reports anterior knee pain 2 years after undergoing primary total knee arthroplasty for rheumatoid arthritis. A Merchant view of the patella is shown in Figure 16. What is the most likely cause of her pain?

Hip 2004 Practice Questions: Set 3 (Solved) - Figure 4

Explanation

Patellar complications commonly occur after primary total knee arthroplasty; therefore, proper component positioning is critical in obtaining a successful result. This patient has lateral tilting and subluxation of the patellar component. Internal rotation of the femoral component has the most deleterious effect on patellar tracking. Lateral placement of the femoral component, medial placement of the patellar component, and external rotation of the tibial component have beneficial effects on patellar tracking. Elevation of the joint line, if not excessive, should not impact patellar tracking. Rand JA: Patellar resurfacing in total knee arthroplasty. Clin Orthop 1990;260:110-117.

References:

Healy WL, Wasliewski SA, Takei R, Oberlander M: Patellofemoral complications following total knee arthroplasty:. Correlation with implant design and patient risk factors. J Arthroplasty 1995;10:197-201.

Question 83

A 16-year-old girl has had pain in the left groin for the past 4 months. She notes that the pain is worse at night; however, she denies any history of trauma and has no constitutional symptoms. There is no history of steroid or alcohol use. Examination reveals pain in the left groin with rotation of the hip. There is no associated soft-tissue mass. A radiograph and MRI scan are shown in Figures 32a and 32b, and biopsy specimens are shown in Figures 32c and 32d. What is the most likely diagnosis?

Explanation

Based on the epiphyseal location and sharp, well-defined borders, the radiograph suggests chondroblastoma. Histologically, multinucleated giant cells are scattered among mononuclear cells. The nuclei are homogenous and contain a characteristic longitudinal groove. Although not seen here, "chicken-wire calcification" with a bland giant cell-rich matrix is also typical for chondroblastoma. Clear cell chondrosarcoma occurs in epiphyseal locations but has a more aggressive histologic pattern and occurs in an older age group. Giant cell tumors occur in the epiphysis but have a more uniform giant cell population histologically. Aneurysmal bone cyst often results in bone remodeling and has a different pathologic appearance. Osteonecrosis has a typical histologic pattern of empty lacunae and necrotic bone. Springfield DS, Capanna R, Gherlinzoni F, et al: Chondroblastoma: A review of seventy cases. J Bone Joint Surg Am 1985;67:748-755. Simon M, Springfield D, et al: Chrondroblastoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 190.

References:

Wold LA, et al: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, pp 62-67.

Question 84

Why is tendon considered an anisotropic material?

Explanation

Anisotropic materials have mechanical properties that vary based on the direction of loading. The relative values of Young's modulus for tendon, ligament, and bone are not relevant to isotropy. The mechanical properties of tendon do change with preconditioning, but this change is related to viscoelasticity. The intrinsic mechanical properties of tendon do vary with the rate of loading, but this variance is related to viscoelasticity. Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 134-180.

References:

Lu L, Kaufman KR, Yaszemski MJ: Biomechanics, 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 85

What is the primary limiting membrane and mechanical support for the periphery of the physis?

Anatomy 2002 Practice Questions: Set 3 (Solved) - Figure 2

Explanation

The perichondrial fibrous ring of La Croix acts as a limiting membrane that provides mechanical support for the bone-cartilage junction of the growth plate. It is continuous with the ossification groove of Ranvier, which contributes chondrocytes for the increase in width of the growth plate. The zone of provisional calcification lies at the bottom of the hypertrophic zone and is the site of initial calcification of the matrix. It is quite weak and usually is the cleavage plane for fractures; therefore, it does not qualify as mechanical support. The last intact transverse septum separates the zone of provisional calcification from the primary spongiosa and provides no real support to the physis. The primary spongiosa is the part of the metaphysis nearest the physis. Netter FH: Growth plate, in Woodburne RT, Crelin ES, Kaplan FS, Dingle RV (eds): The Ciba Collection of Medical Illustrations. Summit, NJ, Ciba-Geigy Corporation, 1987, vol 8, pp 166-167.

References:

Asher MA (ed): Orthopaedic Knowledge Update 1. Chicago, IL, American Academy of Orthopaedic Surgeons, 1984, pp 15-28.

Question 86

An MRI arthrogram of the elbow is shown in Figure 6. Based on these findings, what is the most likely diagnosis?

Upper Extremity 2008 Practice Questions: Set 1 (Solved) - Figure 12

Explanation

MRI arthrography is the imaging study of choice for evaluation of medial collateral ligament injuries. Carrino JA, Morrison WB, Zou KH, et al: Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: Prospective evaluation of two-dimensional pulse sequences for detection of complete tears. Skeletal Radiol 2001;30:625-632.

References:

Munshi M, Pretterklieber ML, Chung CB, et al: Anterior bundle of ulnar collateral ligament: Evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004;231:797-803.

Question 87

A previously asymptomatic 40-year-old man injures his shoulder in a fall. Examination shows that he is unable to lift the hand away from his back while maximally internally rotated. An axial MRI scan of the shoulder is shown in Figure 14. What is the most likely diagnosis?

Anatomy 2008 Practice Questions: Set 1 (Solved) - Figure 33

Explanation

The MRI scan shows detachment of the subscapularis from its insertion on the lesser tuberosity. The examination finding is consistent with a positive lift-off test, also indicating a tear of the subscapularis. Lyons RP, Green A: Subscapularis tendon tears. J Am Acad Orthop Surg 2005;13:353-363.

References:

Warner JJ, Higgins L, Parsons IM, et al: Diagnosis and treatment of anterosuperior rotator cuff tears. J Shoulder Elbow Surg 2001;10:37-46.

Question 88

Figure 54 shows the preoperative radiograph of a 45-year-old woman who is considering total hip arthroplasty with her orthopaedic surgeon. What femoral characteristic is a typical concern in this patient?

Hip & Knee Reconstruction Board Review 2007: High-Yield MCQs (Set 4) - Figure 13

Explanation

Developmental dysplasia of the hip (DDH) leads to early arthritis of the hip as seen in this patient. Although DDH is believed to mostly affect the acetabulum, most patients with DDH also have anatomic aberrations of the femur. Using three-dimensional computer models generated by reconstruction of CT scans, dysplastic femurs were shown to have shorter necks and smaller, straighter canals than the controls. The shape of the canal became more abnormal with increasing subluxation. The studies also have shown that the primary deformity of the dysplastic femur is rotational, with an increase in anteversion of 5 degrees to 16 degrees, depending on the degree of subluxation of the hip. The rotational deformity of the dysplastic femur arises within the diaphysis between the lesser trochanter and the isthmus and is not attributable to a torsional deformity of the metaphysis. Osteopenia is not a concern in a patient with an excellent cortical index (thick cortices and narrow canal). Femoral varus or bowing of the femur is not a typical finding in patients with DDH. Noble PC, Kamaric E, Sugano N, et al: Three-dimensional shape of the dysplastic femur: Implications for THR. Clin Orthop 2003;417:27-40.

References:

Sugano N, Noble PC, Kamaric E, et al: The morphology of the femur in developmental dysplasia of the hip. J Bone Joint Surg Br 1998;80:711-719.

Question 89

A 70-year-old man who underwent an uncomplicated large rotator cuff repair 6 months ago is now seeking a second opinion regarding persistent pain and weakness in his shoulder. Examination reveals that his incision is well healed and unreactive. The surgical report suggests that the tendons were secured back to bone with sutures through the greater tuberosity. Figure 28 shows a radiograph that was obtained 1 week ago. What is the most likely diagnosis?

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

Explanation

Symptoms can persist following a rotator cuff repair for a variety of reasons. In the early postoperative period, infection is the primary concern. Stiffness and loss of motion can occur because of postoperative scarring. Complex regional pain syndrome can occur but is rare, and the diagnosis is not made with a plain radiograph. This radiograph shows a superiorly migrated humeral head that articulates with the acromion, indicating that the repair has failed. While large to massive tears may fail more commonly than once thought, the clinical outcome may be satisfactory in many patients. Mansat P, Cofield RH, Kersten TE, Rowland CM: Complications of rotator cuff repair. Orthop Clin North Am 1997;28:205-213.

References:

Jost B, Pfirrmann CW, Gerber C, Switzerland Z: Clinical outcome after structural failure of rotator cuff repairs. J Bone Joint Surg Am 2000;82:304-314.

Question 90

Accurate evaluation of the upper portion of the subscapularis muscle is best accomplished with active internal rotation

Explanation

Internal rotators of the shoulder include the subscapularis, pectoralis major, teres major, and latissimus dorsi muscles. The subscapularis has two portions, with the upper portion receiving its innervation from the upper subscapular nerve (C5) and the lower portion from the lower subscapular nerve (C5-6). The two tests commonly performed to isolate the internal rotation to the subscapularis muscle are the lift-off test and the belly press test. Electromyographic findings have shown the lift-off test to be more accurate for the lower portion of the subscapularis and the belly press test to be more sensitive for the upper portion. Hintermeister RA, Lange GW, Schultheis JM, Bey MJ, Hawkins RJ: Electromyographic activity and applied load during shoulder rehabilitation exercises using elastic resistance. Am J Sports Med 1998;26:210-220.

References:

Greis PE, Kuhn JE, Schultheis J, Hintermeister R, Hawkins R: Validation of the lift-off test and analysis of subscapularis activity during maximal internal rotation. Am J Sports Med 1996;24:589-593.

Question 91

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 92

A 69-year-old woman reports a painful clicking in her right shoulder. A soft-tissue mass is palpated at the lower portion of the scapula. Based on the MRI scan and biopsy specimens shown in Figures 72a through 72c, what is the most likely diagnosis?

Explanation

Elastofibroma is a rare, benign soft-tissue pseudotumor characteristically located in the subscapular region. Most patients are between 50 and 70 years of age and have pain, decreased shoulder range of motion, or a mass. The lesion usually is best visualized with the arm elevated forward and adducted to displace the scapula laterally and allow the mass to protrude from the chest wall. They are frequently bilateral. Grossly, the mass is ill-defined, oblong or spherical, firm, and ranges in size from 5 cm to 10 cm. These masses appear infiltrative and frequently are mistaken for a sarcomatous lesion. Histologically, the mass is composed of a mixture of intertwining eosinophilic collagen and elastic fibers, and scattered fibroblasts, mucoid material, and fat. Vastamaki M: Elastofibroma scapulae. Clin Orthop Relat Res 2001;392:404-408. Nielsen T, Sneppen O, Mykre-Jensen O, et al: Subscapular elastofribroma: A reactive pseudotumor. J Shoulder Elbow Surg 1996;5:209-213.

References:

Weiss SW, Goldblum JR, Enzinger FM: Enzinger and Weiss's Soft Tissue Tumors, ed 4. Philadelphia, PA, Elsevier, 2001, pp 286-289.

Question 93

The additional risk of complications in organ transplant patients receiving a total joint arthroplasty is attributed to

Explanation

Tannenbaum and associates found that patients who had a joint replacement after an organ transplantation had a rate of infection of 19% (five of 27 joint replacements in 16 patients). They retrospectively reviewed the results of 35 joint (hip or knee) replacements in 19 patients who had an organ transplant. The patients received a standard immunosuppressive induction regimen at the time of the transplantation and were maintained on a combination of prednisone, azathioprine, and cyclosporin A. All patients received antibiotics perioperatively, but antibiotic-impregnated bone cement was not used for any procedure. Six joint replacements in three patients (median patient age of 48.2 years at the time of the arthroplasty) were performed before a renal transplantation. Twenty-four joint replacements in 14 patients (average patient age of 40.9 years at the time of the arthroplasty) were performed after an organ transplantation. Two patients, with an average age of 53.8 years at the time of the arthroplasty, each had a joint replacement both before and after a liver transplantation (a total of five joint replacements). The average duration of follow-up after the first joint replacement was 8.8 years (range, 1 to 23 years). An infection developed around the implant in five patients who had undergone the joint replacement after a transplantation. The average interval from implantation of the prosthesis until detection of the infection was 3.4 years (range, 1 to 6 years). Of two patients who underwent a liver transplant, one had Pseudomonas aeruginosa infection and the other Escherichia coli infection. Of three patients who underwent a renal transplantation, one was infected with Staphylococcus epidermidis, one with Enterococcus, and one with Serratia marcescens.

References:

Tannenbaum DA, Matthews LS, Grady-Benson JC: Infection around joint replacements in patients who have a renal or liver transplantation. J Bone Joint Surg Am 1997;79:36-43.

Question 94

A 54-year-old man sustained a small superficial abrasion over the left acromioclavicular joint after falling from his bicycle. Examination reveals no other physical findings. Radiographs show a displaced fracture of the lateral end of the clavicle distal to a line drawn vertically to the coracoid process. Management should consist of

Trauma 2006 Practice Questions: Set 3 (Solved) - Figure 1

Explanation

Displaced clavicular fractures lateral to the coracoid process (Neer type II and III) are best managed nonsurgically with sling immobilization and physical therapy, starting with pendulum exercises and progressing to active-assisted exercises when comfortable. Supervised therapy should be performed for 3 months or until full painless motion is achieved. In one study by Robinson and Cairns, this form of treatment provided patients with a 86% chance of avoiding a secondary reconstructive procedure. Robinson CM, Cairns DA: Primary nonoperative treatment of displaced lateral fractures of the clavicle. J Bone Joint Surg Am 2004;86:778-782.

Scientific References

:

Deafenbaugh MK, Dugdale TW, Staeheli JW, et al: Nonoperative treatment of Neer type II distal clavicle fractures: A prospective study. Contemp Orthop 1990;20:405-413.

Question 95

Using methylmethacrylate to fill a biopsy hole in the diaphysis of a femur theoretically achieves what purpose?

Basic Science 2002 Practice Questions: Set 1 (Solved) - Figure 33

Explanation

Placing cement over a bone biopsy site prevents tumor contamination by controlling hematoma. Even though the use of cement may impart some strength, the femur is still at significant risk for fracture. The use of bone cement in this manner has not been cleared by the FDA, but many physicians feel that it is appropriate when the patient's health status has been given careful consideration, and the physician has the necessary knowledge and training. The other options are not important reasons to use methylmethacrylate in biopsies. Simon MA, Springfield DS, et al: Biopsy: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 55-65.

References:

Simon MA: Biopsy of musculoskeletal tumors. J Bone Joint Surg Am 1982;64:1253-1257.

Question 96

Which of the following is considered a physiologic effect of anemia?

Explanation

The expected physiologic effects of anemia include an increased heart rate and increased cardiac output. The coronary blood flow requirement increases. There is a decrease in peripheral resistance and blood viscosity.

References:

Carson JL, Duff A, Poses RM, et al: Effect of anemia and cardiovascular disease on surgical mortality and morbidity. Lancet 1996;348:1055-1060.

Question 97

A 34-year-old man sustains an extra-articular fracture of the proximal phalanx of his right index finger in a fall. Examination reveals that the fracture is closed and oblique in orientation. Closed reduction and splinting fail to maintain the reduction. Management should now consist of

Explanation

The patient has an unstable oblique fracture of the proximal phalanx that is easily reducible but unstable; therefore, the treatment of choice is closed reduction and percutaneous pin fixation, followed by casting. Closed reduction and percutaneous pin fixation offers a better functional result than open reduction and plate fixation. Repeat closed reduction and buddy taping is inadequate because of the inherently unstable fracture pattern. Buddy taping will allow the dislocation to recur. The other options represent more aggressive surgical techniques than are necessary to treat this fracture. Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC (eds): Green's Operative Hand Surgery, ed 4. Philadelphia, PA, 1999, pp 711-771.

References:

Green DP, Anderson JR: Closed reduction and percutaneous pin fixation of fractured phalanges. J Bone Joint Surg Am 1973;55:1651-1653.

Question 98

A 50-year-old laborer sustained an isolated closed injury to his heel after falling 11 feet off a wall. A radiograph and a CT scan are shown in Figures 4a and 4b. To minimize the patient's temporary disability and allow him to return to work most rapidly, management should consist of

Explanation

With a severe articular injury to the calcaneus, the ability to achieve satisfactory results with open reduction and internal fixation diminishes. An arthrodesis is often needed to allow a person who works as a laborer to return to work. Recent literature suggests that this can be successfully performed primarily, improving the odds of an earlier return to the labor force at 1 year. Huefner T, Thermann H, Geerling J, Pape HC, Pohlemann T: Primary subtalar arthrodesis of calcaneal fractures. Foot Ankle Int 2001;22:9-14. Coughlin MJ: Calcaneal fractures in the industrial patient. Foot Ankle Int 2000;21:896-905.

References:

Buch BD, Myerson MS, Miller SD: Primary subtalar arthrodesis for the treatment of comminuted calcaneal fractures. Foot Ankle Int 1996;17:61-70.

Question 99

A 19-year-old college football player reports persistent weakness, tingling, and numbness of both upper extremities at half time. He states that these symptoms initially occurred after tackling an opposing player with his head early in the game. History reveals that he has had "burners" in the past that typically resolved within 15 to 30 minutes. Examination reveals pain-free cervical motion, weakness to shoulder abduction testing bilaterally, normal upper extremity reflexes, and decreased sensation over both shoulders and the upper arms. Appropriate initial management should consist of

Explanation

The player's symptoms represent more than the mere "burner syndrome," which leads to unilateral symptoms that typically last less than 1 minute. Return to play following a burner is allowed following nonsurgical management and once the symptoms have subsided and the player exhibits normal strength and motion of the neck and upper extremities. This player has the history, symptoms, and examination findings that are consistent with cervical neurapraxia. Return to play in contact sports is contraindicated with bilateral symptoms prior to MRI evaluation of the cervical spine. CT of the brain is indicated with a history of loss of consciousness or other symptoms suggestive of a concussion. Torg JS, Sennett B, Pavlov H, et al: Spear tackler's spine: An entity precluding participation in tackle football and collision activities that expose the cervical spine to axial energy inputs. Am J Sports Med 1993;21:640-649. Torg JS: Cervical spinal stenosis with cord neurapraxia and transient quadriplegia. Sports Med 1995;20:429-434.

References:

Torg JS, Guille JT, Jaffe S: Injuries to the cervical spine in American football players. J Bone Joint Surg Am 2002;84:112-122.

Question 100

Figures 51a through 51c show the radiographs of a 7-year-old soccer player who reports a gradual onset of midfoot pain that began shortly after the start of soccer season. He states that the pain is worse with activity and is partially alleviated by rest. Examination reveals soft-tissue swelling, and tenderness and warmth in the region of the talonavicular and navicular cunieform joints. Management should consist of

Explanation

Osteochondrosis of the tarsal navicular (Kohler disease) is an infrequent cause of midfoot pain in children, and the etiology is unknown. The typical radiographic findings include flattening and irregular ossification of the tarsal navicular. The medial cunieform and talus maintain their normal articular contours. The acute process is best treated with rest and immobilization. A short leg walking cast results in relief of pain and a quicker return to activity compared with orthotics, although long-term success is similar with either method of treatment. Children may return to activities when the symptoms subside. The radiographic appearance of the talus begins to normalize by about 8 to 10 months following the onset of symptoms.

References:

Lutter LD: Sports-related injuries, in Drennan JC (ed): The Child's Foot and Ankle. New York, NY, Raven Press, 1992.

Orthopedic Board Review Mock Exam #603: 100 High-Yield MCQs

ABOS & OITE Mock Exam Set 205: 100 High-Yield Orthopedic MCQs

Key Takeaway

Scientific References

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Chapter Index