Master Urinary Tract Stones: 2019 Exam Questions

Randomized Orthopedic Board Review Practice

Welcome to this customized practice session containing 100 randomly selected high-yield multiple-choice questions (MCQs).
These questions have been pulled from our extensive master database of OITE and AAOS board-style questions to provide you with an unpredictable, exam-like simulation.

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Comprehensive 100-Question Exam

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Question 1

Figures 35a and 35b show the radiographs of a 7-year-old patient who has progressive deformity of the right thigh accompanied by a dull persistent pain radiating to the knee. Examination reveals an obvious bulge in the right thigh, with flexion of the hip beyond 50° only if the hip is allowed to externally rotate. Management should consist of

Explanation

DISCUSSION: The patient has radiographic signs of osteogenesis imperfecta, including osteopenia, mild acetabular protrusio, cortical thinning, and bowing associated with anterior stress fracturing. The treatment of choice is correction of the bow with osteotomies, followed by intramedullary fixation to prevent further deformity. Biphosphonates, such as pamidronate, may be useful in increasing bone density and preventing fractures. Large multicenter studies on biphosphonate efficacy are currently in progress.
REFERENCES: Zionts LE, Ebramzadeh E, Stott NS: Complications in the use of the Bailey-Dubow extensible nail. Clin Orthop 1998;348:186-195.
Luhmann SJ, Sheridan JJ, Capelli AM, Schoenecker PL: Management of lower-extremity deformities in osteogenesis imperfecta with extensible intramedullary rod technique: A 20-year experience. J Pediatr Orthop 1998;18:88-94.
Glorieux FH, Bishop NJ, Plotkin H, Chabot G, Lanoue G, Travers R: Cyclic administration of pamidronate in children with severe osteogenesis imperfecta. N Engl J Med 1988;339:947-952.

Question 2

Which factor has the most negative influence on the success of knee osteochondral allograft transplantation?

Explanation

DISCUSSION
The images illustrate a large unstable osteochondral lesion of the medial femoral condyle. Radiographs and MR images clearly show deep subchondral bone involvement. The appropriate choice of surgery is OCA transplantation, which is indicated for primary treatment of large cartilage lesions, osteochondral lesions, and salvage procedure from failed prior cartilage surgery. Correction of mechanical axis malalignment, ligamentous insufficiency, and meniscal deficiency should also be addressed. ACI alone or an arthroscopic microfracture procedure would not address the bone defect, leaving an uneven articular surface. Although an osteotomy may be a viable choice, a distal femoral varus osteotomy would increase the contact pressure in the medial compartment and worsen the situation.
The histologic anatomy of articular cartilage is well described. The superficial layer or lamina splendens contains a small amount of proteoglycan with collagen fibrils arranged parallel to the articular surface. In contrast, the deep zone contains the largest-diameter
collagen fibrils, oriented perpendicular to the joint surface, and the highest concentration of proteoglycans.

Video 54 this video is uploaded at
CLINICAL SITUATION FOR QUESTIONS 51 THROUGH 54
Figures 51a and 51b are the radiographs of an 18-year-old football linebacker who was involved in a tackle and fell onto an outstretched left arm. He had immediate pain and deformity of his left elbow.

Question 3

Which of the following factors has been shown to be the strongest predictor of screw cutout of a dynamic compression hip screw used for an intertrochanteric femur fracture?

Explanation

DISCUSSION: Illustration A found below depicts the method to calculate Tip-apex distance (TAD). The tip-apex distance is the sum of the distances from the tip of the lag screw to the apex of the femoral head as seen on the AP and lateral radiographs.
Baumgaertner et al reported that he had no screws cut out if the tip-apex distance was less than 25mm. Tip-apex distance was the strongest predictor of cutout. Increasing age of the patient, poor reduction, use of a high angle sideplate, and unstable fracture were weaker predictors of cutout.
Kyle et al demonstrated that obtaining an anatomic reduction when using a sliding hip screw with intertrochanteric fractures leads to the best radiographic and clinical outcomes.

Question 4

Deep venous thromboses are primarily composed of red blood cells and fibrin. What is fibrin?

Explanation

Fibrin is the end product of the coagulation cascade that results from the cleavage of fibrinogen by thrombin (factor IIa). Platelets are a key component in arterial thromboses. Collagen initiates the intrinsic arm of the coagulation cascade. Thromboplastin is a procoagulant substance that triggers the extrinsic arm of the coagulation cascade. The fibrinolytic system is the regulatory pathway that breaks down cross-linked fibrin.

Question 5

With the increasing availability of total hip arthroplasty (THA) to younger patients with hip osteoarthritis, there has been increased use of alternative bearing surfaces. Compared to a ceramic-on-ceramic articulation, which of the following is a specific advantage of a metal-on-metal bearing surface?

Explanation

DISCUSSION: Alternative bearing surfaces in THA have received much attention in recent years as more and more hip arthroplasties are being performed on younger patients with hip arthritis. The two most popular nonmetal-on-polyethylene bearing surfaces are metal-on-metal and ceramic-on-ceramic. There are arguments supporting the use of either, but ceramic bearings have been shown to have a theoretic increased risk of fracture compared with cobalt-chromium. This has been shown to be clinically relevant with zirconium ceramics. Newer alumina ceramics are being produced with lower porosity and grain size and with higher density and purity, resulting in lower fracture risk but still greater than that of cobalt-chromium.
REFERENCES: Heisel C, Silva M, Schmalzried TP: Bearing surface options for total hip replacement in young patients. Instr Course Lect 2004;53:49-65.
D’Antonio J, Capello W, Manley M, et al: New experience with alumina-on-alumina ceramic bearings for total hip arthroplasty. J Arthroplasty 2002;17:390-397.

Question 6

A 55-year-old woman with a history of untreated idiopathic scoliosis has had neurogenic claudication for the past several months. MRI reveals spinal stenosis at L2-L3, L3-L4, and L4-L5. Radiographs show a 45° lumbar curve from T10 to L4, with a degenerative spondylolisthesis at L4-L5. Laminectomy at the stenotic levels and stabilization of the deformity are planned. Which of the following is NOT considered an absolute indication for extending the fusion to the sacrum, rather than stopping at L5?

Explanation

DISCUSSION: There are several indications for extending adult scoliosis fusions to the sacrum, rather than stopping in the lower lumbar spine. These indications include posterior column deficiencies at L5-S1, such as spondylolysis and laminectomy, and deformities extending to the sacrum, such as fixed tilt of L5-S1 or sagittal imbalance. MRI signal changes in the L5-S1 disk do not preclude stopping the fusion at L5. Some surgeons use diskography or diagnostic facet blocks to evaluate the integrity of the L5-S1 level prior to stopping the fusion at L5. Long scoliosis fusions stopping at L5 have a significant risk of failure, highlighting the importance of careful selection of fusion levels.
REFERENCES: Bradford DS, Tay BK, Hu SS: Adult scoliosis: Surgical indications, operative management, complications, and outcomes. Spine 1999;24:2617-2629.
Bridwell KH: Where to stop the fusion distally in adult scoliosis: L4, L5, or the sacrum? Instr Course Lect 1996;45:101-107.
Edwards CC II, Bridwell KH, Patel A, et al: Long adult deformity fusions to L5 and the sacrum: A matched cohort analysis. Spine 2004;29:1996-2005.

Question 7

1 and 2 demonstrate the radiographs obtained from a year-old woman with end-stage debilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplasia and underwent hip osteotomy as an adolescent. Over the years, nonsurgical treatment, including weight loss, activity modifications, and intra-articular injections, has failed. Her infection work-up reveals laboratory findings within defined limits.The patient undergoes successful primary THA with a metal-on-metal bearing. At year follow-up, she reports no pain and is highly satisfied with the procedure. However, 3 years after the index procedure, she reports atraumatic right hip pain that worsens with activities. Radiographs reveal the implants in good position with no sign of loosening or lysis. An initial laboratory evaluation reveals a normal sedimentation rate and C-reactive protein (CRP) level. The most appropriate next diagnostic step is

Explanation

DISCUSSION:
THA has proven to be durable and reliable for pain relief and improvement of function in patients with end-stage arthritis. Appropriate bearing selection is critical to minimize wear and hip complications. A
metal-on-metal articulation is associated with excellent wear rates in vitro. Because it offers a low wear rate with large femoral heads, it is an attractive bearing choice for THA. However, local soft-tissue reactions, pseudotumors, and potential systemic reactions—including renal failure, cardiomyopathy, carcinogenesis, and potential teratogenesis after the possible transfer of metal ions across the placental barrier—make metal-on-metal bearings less desirable and relatively contraindicated for younger women of child-bearing age.The work-up of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including the erythrocyte sedimentation rate, C-reactive protein (CRP) level, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging, including MRI with MARS, should be performed to evaluate for the presence of fluid collections, pseudotumors, and abductor mechanism destruction. Infection can coexist with metal-on-metal reactions, so when indicated (if the CRP level is elevated), a hip arthrocentesis should be obtained. However, in this setting, a manual cell count and differential should be obtained because an automated cell counter may provide falsely elevated cell counts. The results of revision surgery for a failed metal-on-metal hip prosthesis can be variable. The amount of local tissue destruction and the integrity of the hip abductor mechanism can greatly influence outcomes. Instability is the most common complication following a revision of failed metal-on-metal hip replacements.

Question 8

Which of the following radiographic findings would be characteristic of the knee joints of a patient with neuropathic osteoarthropathy of the knee?

Explanation

Neuropathic osteoarthropathy (a.k.a. Charcot joint) develops most often in weight-bearing joints. The most likely cause is diabetes mellitus, but it is also associated with syphilis, leprosy, yaws, congenital insensitivity to pain, spina bifida, myelomeningocele, syringomyelia, aerodystrophic neuropathy, amyloid neuropathy, peripheral neuropathy of alcoholism, spinal cord injury, peripheral nerve injury, post-transplant neuropathy, and intraarticular steroid injections.
The loss of sensation to the joint is followed by severe degenerative changes, osteophyte formation, articular and subchondral fractures, and often calcification of surrounding soft tissues. In the knee, this is a tricompartmental disease and will not selectively affect one compartment over another.

Question 9

Which of the following methods best aids in diagnosis of an interdigital neuroma?

Explanation

DISCUSSION: History and physical examination are still the gold standard for diagnosis of an interdigital neuroma. Ultrasound and MRI may be helpful adjuncts but are dependent on equipment and operator expertise. Web space injection may be helpful for diagnostic and therapeutic purposes. Electromyography and nerve conduction velocity studies are of little benefit for distal lesions.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 145-147.
Bennett GL, Graham CE, Mauldin DM: Morton’s interdigital neuroma: A comprehensive treatment protocol. Foot Ankle Int 1995;16:760-763.

Question 10

A 23-year-old otherwise healthy 6-ft, 4-in basketball player complains of pain in his knees. An examination reveals localized tenderness to palpation over the inferior pole of the patella. The patient notes a significant exacerbation of his pain when the examiner takes the knee from flexion to extension. Review Topic

Explanation

Patellar tendonitis is common in jumping sports such as basketball and volleyball. The pain is localized to the inferior border of the patella and is exacerbated by extension of the knee. Treatment for the vast majority of patients is nonsurgical and includes nonsteroidal anti-inflammatory drugs, physical therapy, and orthoses (patella tendon strap). Iliotibial band friction most commonly occurs in cyclists and runners (especially those who run up hills) and is a result of abrasion between the iliotibial band and the lateral femoral condyle. Localized tenderness with the knee flexed at 30 degrees is common. The Ober test may be helpful in making the diagnosis. Semimembranosis tendonitis most commonly occurs in male athletes during their fourth decade of life. The diagnosis is usually made with an MRI scan or nuclear imaging. Quadriceps tendonitis is similar to patellar tendonitis but is much less common. The pain may be associated with clicking and is localized to the superior border of the patella.

Question 11

Which of the following is a recognized consequence of hip fusion?

Explanation

DISCUSSION: Low back pain is an expected long-term complication of fusion; ipsilateral knee laxity is frequently encountered, as is degeneration of the contralateral hip. Hip fusion is equally valuable for both men and women, with both genders reporting satisfactory sexual function. Female patients often deliver by elective Cesarean section, although vaginal deliveries are reported.
REFERENCES: Liechti R (ed): Hip Arthrodesis and Associated Problems. Berlin, Germany, Springer-Verlag, 1978, pp 109-117.
Sponseller PD, McBeath AA, Perpich M: Hip arthrodesis in young patients: A long-term follow-up study. J Bone Joint Surg Am 1984;66:853-859.

Question 12

A 13-year-old gymnast presents with ongoing knee pain for the past few months. She tried conservative measures including kinesiotaping, physical therapy and rest. On physical exam, she has normal valgus alignment, negative patellar tilt and discomfort with resisted open chain knee extension. A representative radiographs are shown in Figure A-C. What is the most likely clinical diagnosis? Review Topic

Explanation

Based on history, physical examination and radiographic findings this patient has patellofemoral syndrome
Evaluation of a patient with patellofemoral pain requires a physical examination and plain radiographs. Appropriate examination of all structures around the knee is critical to rule out other diagnoses. An MRI is useful for evaluating intra-articular or intra-osseous lesions, if clinical suspicion is suggestive of this. Treatment is predominantly conservative, with focus on low impact exercises that maximize aerobic conditioning.
Earl et al. review the epidemiology, etiology and management of patellofemoral syndrome. They note that there is no clear cause of this issue, although issues related to the quadriceps and dynamic malalignment may be contributory.
Outerbridge et al. describe overuse injuries in the young athletic patient. They provide an overview of diagnosis and management specific to this patient population.
Figures A, B and C show AP, lateral and merchant radiographs of a normal knee in a skeletally immature individual. No osseous abnormalities are identified.
Incorrect

Question 13

Overgrowth of a limb in a patient with neurofibromatosis type 1 (NF1) is most likely associated with the presence of

Explanation

DISCUSSION: Plexiform neurofibromas are lesions found in patients with NF1. Clinical reports show the prevalence of plexiform neurofibroma to be 20% to 30% but increases to 40% when imaging studies are routinely obtained. The lesions are characterized by diffuse hypertrophy of the involved nerves but with preservation of the nerves’ fascicular organization. The lesions may involve the dermis or may arise in the deeper structures. Palpation of a dermal lesion provokes an image of a “bag of worms.” Plexiform neurofibromas may cause disfigurement and hyperpigmentation of the overlying skin. The lesions also can cause diffuse hypertrophy of the soft tissue and bone, with resultant changes ranging from a relatively minor limb-length discrepancy to gigantism of the entire extremity. Dural ectasia is frequently found in patients with NF1. Therefore, MRI should be obtained prior to planning spinal procedures in these patients; however, dural ectasia is not the cause of limb overgrowth. Lisch nodules are benign hamartomas of the iris. The lesions are uncommon during early childhood but are found in all adults with NF1. Juvenile xanthogranuloma has a low occurrence rate in patients with NF1; its presence is associated with juvenile chronic myeloid leukemia. Malignant peripheral nerve sheath tumors, formally called neurofibrosarcoma, result from malignant degeneration of a plexiform neurofibroma. This condition occurs in up to 4% of patients with NF1. Localized pain, an enlarging mass, or progressive neurologic symptoms suggest a malignant peripheral nerve sheath tumor in a patient with NF1. However, progressive neurologic symptoms also may occur with benign growth of a plexiform neurofibroma.
REFERENCES: Alman BA, Goldberg MJ: Syndromes of orthopaedic importance, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 287-338.
Greene WB: Neurofibromatosis type I, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1584-1588.

Question 14

In a patient who has undergone fusion with instrumentation from T4 to the sacrum for adult scoliosis, at which site is a pseudarthrosis most likely to be discovered?

Explanation

DISCUSSION: Although pseudarthrosis can be found anywhere within the spine that has been fused using long multisegmental fixation to the sacrum, it most commonly occurs at the lumbosacral junction. The thoracolumbar junction is another common site of potential pseudarthrosis. In this location, the anatomy changes from lumbar transverse processes to thoracic through the transition zone, and overlying instrumentation often makes it difficult to obtain enough sound bone on decorticated bone to achieve a successful fusion.
REFERENCES: Saer EH III, Winter RB, Lonstein JE: Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis: An improved method. Spine 1990;15;650-653.
Kostuik JP, Hall BB: Spinal fusions to the sacrum in adults with scoliosis. Spine

1983;8:489-500.
Balderston RA, Winter RB, Moe JH, et al: Fusion to the sacrum for nonparalytic scoliosis in the adult. Spine 1986;11:824-829.

Question 15

A 9-year-old boy is injured while playing soccer. His examination reveals painful range of motion between 5° and 75°. There is tenderness on the medial side of his knee. There is no effusion, a grade 1A Lachman test, and severe pain over the medial epicondyle of the knee. Varus stress is negative and pain is elicited with valgus stress. Initial radiographs were negative for abnormality. What is the most likely area of injury?

Explanation

This patient likely has a physeal injury to the distal femoral physis. Stress radiographs or an MRI scan will most reliably reveal this diagnosis. The growth plate, when injured, is most commonly fractured through the hypertrophic zone of cartilage, its weakest point. This patient is optimally treated in a cylindrical or long-leg cast.

Question 16

A 30-year-old man who underwent an anterior lumbar diskectomy and fusion at L4-5 and L5-S1 through an anterior retroperitoneal approach 1 month ago now reports he is unable to obtain and maintain an erection. The most likely cause of this condition is

Explanation

DISCUSSION: Sexual dysfunction is a common condition after extensive anterior lumbar surgical dissection. Erectile dysfunction usually is nonorganic but may be related to parasympathetic injury. The parasympathetic nerves are deep in the pelvis at the level of S2-3 and S3-4 and usually are not involved in the surgical field for anterior L4-5 and L5-S1 procedures. Retrograde ejaculation is the result of injury to the sympathetic chain on the anterior surface of the major vessels crossing the L4-5 level and at the L5-S1 interspace. Erectile function and orgasm are not affected by sympathetic injury. The pudendal nerve is primarily a somatic nerve and is not located in the surgical field.
REFERENCES: Flynn JC, Price CT: Sexual complications of anterior fusion of the lumbar spine. Spine 1984;9:489-492.
Johnson RM, McGuire EJ: Urogenital complications of anterior approaches to the lumbar spine. Clin Orthop 1981;154:114-118.

Question 17

During head-on motor vehicle collisions occurring at highway speeds, airbag-protected individuals have a decreased rate (as compared to non-airbag protected individuals) of all of the following EXCEPT:

Explanation

DISCUSSION: The referenced study by Loo et al. studied the interaction between airbags/seatbelts and mechanism of the crash (ie. front vs. side impact) and the injury patterns in these patients. They found that in frontal crashes, airbags reduced Glasgow Coma Scale severity in brain injury, facial fracture, shock, thoracoabdominal injuries and the need for extrication. Frontal airbags also had a protective effect on lower extremity fractures, but had no significant protective effect on pelvic fractures.

Question 18

Figures 1 and 2 are the radiographs of an 18-year-old man who had surgery 6 months ago at an outside institution. He is being referred now because he has persistent pain. He is tender over the scaphoid at the snuffbox. What is the most appropriate next imaging step in his pain workup?

Explanation

EXPLANATION:
Scaphoid nonunions are difficult to diagnose on plain radiographs, which offer poor reliability when attempting to determine if there is bridging trabeculae crossing the fractures site. CT scans are more useful for diagnosing scaphoid nonunion. When scanned using conventional axial cuts, the slices mayskip through the fracture nonunion site, thereby missing the defect, even with reformats. MR imaging is useful in diagnosing acute scaphoid fractures and has a high sensitivity and diagnostic value for excluding scaphoid fractures as well. Contrast does not enhance the utility of MR imaging in fracture diagnosis.

Question 19

What is the most common malignant tumor of the foot?

Explanation

DISCUSSION: Whereas chondrosarcoma is the most frequently occurring malignant bone tumor of the foot and synovial sarcoma is the most common soft-tissue foot malignancy, the most common malignant tumor overall is melanoma. It constitutes approximately 25% of lesions found on the lower extremity. Furthermore, 31% of all melanomas arise in the foot.
REFERENCES: Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 11-26.
Bos GD, Ester RJ, Woll TS: Foot tumors: Diagnosis and treatment. J Am Acad Orthop Surg 2002;10:259-270.

Question 20

A 22-month-old girl has cerebral palsy. Which of the following findings is a good prognostic indicator of the child’s ability to walk in the future?

Explanation

DISCUSSION: For the parachute test, the examiner holds the child prone and then lowers the child rapidly toward the floor. The parachute reaction is normal or positive if the child reaches toward the floor. The Moro or startle reflex should not be present beyond age 6 months. Asymmetric tonic neck reflex, extensor thrust, and absent foot placement are abnormal findings at any age.
REFERENCES: Bleck EE: Orthopaedic Management in Cerebral Palsy. Lavenham, Suffolk, The Lavenham Press, 1987, pp 121-139.
Tachdjian MO: The neuromuscular system: Cerebral palsy, in Wickland EH Jr (ed): Pediatric Orthopaedics, ed 2. Philadelphia, PA, WB Saunders, 1990, vol 2, p 1621.

Question 21

A patient who underwent intramedullary nailing of a femoral shaft fracture 2 weeks ago now reports groin pain. What is the next most appropriate step in management?

Explanation

Whereas ipsilateral fractures of the femoral neck and shaft are uncommon, it is critical to recognize a femoral neck fracture that may occur in conjunction with a femoral shaft fracture. The combined injury is seen in 2% to 9% of femoral shaft fractures and may initially be missed in as many as one third of the cases. Preoperative examination of a thin cut CT scan and dedicated AP internal rotation views of the femoral neck can help identify this injury. In addition, the intraoperative AP and lateral hip fluoroscopic view should be examined, and a dedicated radiograph of the hip obtained at the conclusion of the surgery. At follow-up, Tornetta and associates has recommended
obtaining a dedicated AP radiograph of the hip with the leg internally rotated 15 to 20 degrees. Because the femoral neck is anteverted, 15 to 20 degrees of internal rotation of the hip offers the best view of the femoral neck. Whereas associated lumbar spine pathology may cause groin pain, the presence of a missed femoral neck fracture must first be ruled out prior to investigating other sources of pain.

Question 22

A 64-year-old man who was involved in a high-speed motor vehicle accident 6 weeks ago has been in the ICU with a closed head injury. Examination reveals that his range of motion for external rotation to the side is -30 degrees. Radiographs are shown in Figures 28a and 28b. What is the most likely diagnosis?

Explanation

DISCUSSION: The patient has a posterior shoulder dislocation. The AP radiograph shows overlapping of the humeral head on the glenoid. The scapular Y view shows his humeral articular surface posterior to the glenoid. The posterior shoulder dislocation is frequently missed because the patient is comfortable in the "sling" position with the arm adducted and internally rotated across the abdomen. The marked restriction in external rotation on examination raises the suspicion of a posterior dislocation, adhesive capsulitis, or glenohumeral osteoarthritis. The posterior dislocation is diagnosed based on the radiographic findings. An axillary view or CT is recommended to better evaluate the dislocation.
REFERENCES: Robinson CM, Aderinto J: Posterior shoulder dislocations and

fracture-dislocations. J Bone Joint Surg Am 2005;87:639-650.
Cicak N: Posterior dislocation of the shoulder. J Bone Joint Surg Br 2004;86:324-332.

Question 23

repair of the rotator cuff

Explanation

Humeral arthroplasty is indicated when there is a defect equivalent to more than 45 percent of the articular surface of the humeral head or dislocation that had been present for more than six months. Posterior dislocations is often missed during initial management. Twenty-five of forty-one dislocations were diagnosed in less than six months.( Hawkins RJ,JBJS 87)

Question 24

Which of the following conditions associated with a closed fracture of the clavicle indicates the need for open reduction and internal fixation?

Explanation

Injuries to underlying vascular structures associated with clavicle fractures require exploration and stabilization. Brachial plexus injuries recover spontaneously in two thirds of patients. Displaced and segmental fractures may undergo closed reduction. Open treatment of clavicle fractures have been discouraged secondary to technical difficulties and nonunion. A floating shoulder (displaced clavicle and scapular neck fractures is an indication for ORIF but not humeral neck fracture.)

Question 25

Figure 13 shows the clinical photograph of a 66-year-old man who has had an increasingly painful right foot deformity for the past 3 years. Examination reveals that the subtalar joint is fixed in 15° of valgus, and forefoot supination can be corrected to 10° from neutral. Nonsurgical management has failed to provide relief. Treatment should now consist of

Explanation

DISCUSSION: The most important determining factor for correction of an adult flatfoot without an arthrodesis is the flexibility of the subtalar and transverse tarsal joints. Rigid deformities cannot be corrected with a medial sliding calcaneal osteotomy with FDL transfer or a subtalar arthroereisis. Isolated subtalar or talonavicular arthrodesis does not correct the deformities entirely. If the patient has forefoot supination that can be corrected to less than 7°, an isolated subtalar fusion is a possible alternative.
REFERENCE: Mann RA: Flatfoot in adults, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, Mosby, 1993, pp 757-784.

Question 26

A patient sustains a comminuted calcaneus fracture. Three months after the injury the patient complains of shoewear problems secondary to clawing of the lesser toes. What is the most likely explanation for this deformity?

Explanation

DISCUSSION: Contracture of the intrinsic flexor muscles of the foot can be the result of unrecognized foot compartment syndrome. Foot compartment syndrome is a known complication of calcaneus fractures.
Myerson reported 3/43 patients in his series below had chronic foot compartment syndrome. There are 9 compartments in the foot: (1) medial, (2) superficial, (3) lateral, (4) adductor, (5-8) four interossei, and (9) calcaneal. The plantar fascia limits the space available for hematoma and swelling, causing damage to the intrinsic flexors of the foot (particularly the lumbricals and interossei), resulting in clawtoes.

Question 27

A professional baseball team has several pitchers with complaints of velocity loss with their pitches and shoulder pain of their dominant shoulders during spring training. Pitch counts are properly monitored. The average glenohumeral internal rotation deficit on the pitching staff is 45 degrees. The best intervention would be: Review Topic

Explanation

Glenohumeral Internal Rotation Deficit (GIRD) is a phenomenon that occurs in baseball pitchers and is due to posterior capsular tightness. Treatment should begin with a therapy program addressing the pathologic posterior capsule.
GIRD is a phenomenon that is frequently found in high-level overhead throwing athletes, predominantly baseball pitchers. It is defined as the measured difference in internal rotation between the non-dominant arm and dominant arm. Worsening range of motion deficits are seen with increased repetitions, both over a single season and a career. GIRD > 25º is associated with development of shoulder pathologies or pain requiring periods of inactivity. Cessation of overhead throwing activities and initiation of a stretching program to address posterior capsular contractures is largely effective (90% in some series).
Burkhart et al. reviewed the conditions associated with high-level overhead throwing athletes shoulders, culminating in a theory of pathologic progression to "dead arm syndrome" (loss of velocity and effective pitching). Their theory attributes adaptive hyperexternal rotation (occurs during late-cocking / early acceleration phases of pitching) to lead to posterior-inferior capsular contracture and GIRD. Subsequent injuries to anterior structures - including SLAP lesions - would then occur.
Illustration A is a cartoon depiction of how to perform the sleeper stretch. This is a common component of a pitcher's maintenance stretching program.
Incorrect Answers:

Question 28

A 4-year-old boy sustained a nondisplaced, but complete, fracture of the left proximal tibial metaphysis 1 year ago. The fracture healed uneventfully in an anatomic position. Examination of the injured extremity now reveals 18° of valgus compared with 3° of valgus on the opposite side. Management should now include

Explanation

DISCUSSION: The development of a valgus deformity after this type of fracture is a well-known occurrence, and the patient’s parents should be informed about this risk. In a patient who is age 4 years, the natural history is one of gradual correction by the development of a physiologic varus deformity at the distal tibial physis; therefore, no active intervention is needed at this time. Bracing has no effect on the deformity, and the child is too young for any procedure on the growth plate. Proximal tibial osteotomy is reserved until the patient nears skeletal maturity because of the risk of recurrence of the deformity. Lateral stapling can be done near skeletal maturity if the deformity persists, but this is unlikely to be necessary.
REFERENCES: Zionts LE, MacEwen GD: Spontaneous improvement of posttraumatic tibia valga. J Bone Joint Surg Am 1986;68:680-687.
Beaty JH, Kumar A: Fractures about the knee in children. J Bone Joint Surg Am 1994;76:1870-1880.

Question 29

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

Explanation

DISCUSSION: While the patellar tendon ligament is considered by many to be the tissue of choice for ACL reconstruction, more recent studies have shown that the quadruple semitendinosus and gracilis tendon graft has the greatest stiffness and offers the highest maximum load to failure.
REFERENCES: Hamner DL, Brown CH Jr, Steiner ME, Hecker AT, Hayes WC: Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: Biomechanical evaluation of the use of multiple strands and tensioning techniques. J Bone Joint Surg Am 1999;81:549-557.
Cooper DE, Deng XH, Burstein AL, Warren RF: The strength of the central third patellar tendon graft: A biomechanical study. Am J Sports Med 1993;21:8l8-823.
Brown CH Jr, Steiner ME, Carson EW: The use of hamstring tendons for anterior cruciate ligament reconstruction: Technique and results. Clin Sports Med 1993;12:723-756.
Engebretsen L, Lewis JL: Graft selection and biomechanical considerations in ACL reconstruction. Sports Med Arthroscopy Rev 1996;4:336-341.

Question 30

The stability of the longitudinal arch of the foot during standing with equal weight on both feet is due primarily to

Explanation

The longitudinal arch is stabilized by heavy ligamentous structures surrounding the tarsal joints with passive assistance from the plantar aponeurosis. EMG studies have shown little or no intrinsic muscle activity during quiet standing.

Question 31

A 33-year old man sustains a posterior elbow dislocation after a fall. Attempts at closed reduction result in recurrent instability. What is the most common ligamentous injury found at the time of surgical stabilization?

Explanation

Classic posterior elbow dislocations result from a posterolateral rotatory mechanism, whereby the hand is fixed (typically on the ground) while the weight of the body creates a valgus and external rotation moment on the elbow. This results first in tearing of the lateral collateral ligament that proceeds medially through the anterior and posterior joint capsules, ending with potential involvement of the ulnar collateral ligament (but this is not universal). McKee and associates assessed the lateral soft-tissue injury pattern of elbow dislocations
with and without associated fractures at the time of surgery. Injury to the lateral collateral ligament complex was seen in every case, with avulsion from the distal humerus as the most common finding. Midsubstance
tears, proximal avulsions, and distal bony avulsions of the ulnar collateral ligament are less common.

Question 32

Which of the following complications may occur subsequent to resurfacing hip arthroplasty for osteonecrosis of the hip but not after total hip arthroplasty?

Explanation

DISCUSSION: Advocates of resurfacing hip arthroplasty cite preservation of the proximal femoral bone stock as the main advantage of this procedure over total hip arthroplasty. Fracture of the retained femoral neck has been reported following resurfacing arthroplasty. The exact etiology of the latter is unknown. Technical errors, such as notching of the femoral neck or possibly disruption of the blood supply to the femoral head during extensive soft-tissue exposure, may result in femoral neck fracture.
REFERENCES: Gabriel JL, Trousdale RT: Stem fracture after hemiresurfacing for femoral head osteonecrosis. J Arthroplasty 2003;18:96-99.
Amstutz HC, Campbell PA, Le Duff MJ: Fracture of the neck of the femur after surface arthroplasty of the hip. J Bone Joint Surg Am 2004;86:1874-1877.

Question 33

In the evaluation of somatosensory-evoked potential waveforms for intraoperative neuromonitoring for spinal surgery, the minimum criteria for determining potentially significant changes include Review Topic

Explanation

The established criteria for interpreting a significant change are 50% decrease in signal amplitude, 10% latency increase, and/or a complete loss of potential. Intraoperative spinal cord monitoring during spinal surgery generally consists of a combination of monitoring modalities. Somatosensory-evoked potentials in combination with intraoperative electromyography can provide adequate coverage of sensory and motor components of spinal cord and nerve root function. Significant changes in evoked potential waveform characteristics can reflect dysfunction of the ascending somatosensory system.

Question 34

A 35-year-old woman began to train for a half marathon. After 8 weeks of increasing her mileage, what changes can you expect in her Achilles tendon?

Explanation

Training increases turnover of type I collagen, promoting both synthesis and degradation of collagen and a net increase synthesis of type I collagen in tendon-related tissue. Strenuous endurance training has resulted in decreased collagen cross-links, suggesting increased collagen turnover, but decreased collagen maturation. In human studies, physical training results in increased turnover of collagen. Synthesis and degradation are elevated initially when beginning an exercise program, but degradation products decrease overall. It is not known if activity levels in humans affect the diameter of collagen fibrils or the cross-sectional area of tendons.

Question 35

Figure 29 is the radiograph of a 30-year-old man who sustained an isolated tibial shaft fracture. What is the most common deformity with nonsurgical management?

Explanation

Studies have shown that approximately 25% of diaphyseal fractures of the tibia with intact fibulae will go onto varus malunion if treated nonsurgically. Limb-length
discrepancies are also common. Here the fibula acts as a strut, preventing valgus collapse but predisposing to varus collapse. Valgus and procurvatum is the typical deformity in proximal tibial fractures.

Question 36

A patient notes pain under the first metatarsophalangeal joint following a soccer injury. The MRI scans shown in Figures 27a and 27b reveal what pathologic finding?

Explanation

DISCUSSION: The MRI scans show a complete disruption of the sesamoid complex with proximal retraction of the medial sesamoid and high signal originating from the site normally occupied by the plantar plate (metatarsophalangeal ligament). This injury is the result of a hyperextension injury and is a severe variant of a turf toe.
REFERENCES: Watson TS, Anderson RB, Davis WH: Periarticular injuries to the hallux metatarsophalangeal joint in athletes. Foot Ankle Clin 2000;5:687-713.
Tewes DP, Fischer DA, Fritts HM, et al: MRI findings of acute turf toe: A case report and review of anatomy. Clin Orthop 1994;304:200-203.

Question 37

The Lisfranc ligament connects the base of the

Explanation

DISCUSSION: The Lisfranc ligament arises from the lateral surface of the first (medial) cuneiform and is directed obliquely outward and slightly downward to insert on the medial surface of the second metatarsal base. It is the strongest of the tarsometatarsal interosseous ligaments.
REFERENCES: Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993.
Solan MC, Moorman CT III, Miyamoto RG, et al: Ligamentous restraints of the second tarsometatarsal joint: A biomechanical evaluation. Foot Ankle Int 2001;22:637-641.

Question 38

A 46-year-old woman reports pain and a shortened appearance of her toe after undergoing a Keller resection arthroplasty 2 years ago for hallux rigidus. Examination reveals mild swelling and motion limited to 25 degrees at the metatarsophalangeal joint. Radiographs show large dorsal osteophytes on the first metatarsal head, 50% resection of the proximal phalanx, and complete loss of the metatarsophalangeal joint space. Which of the following is considered the most reliable procedure to improve her pain and the appearance of her toe?

Explanation

DISCUSSION: Because the patient has significant arthritis, arthrodesis is the treatment of choice. Adding a bone graft will prevent further shortening and add length to her toe, resulting in improved cosmesis. A cheilectomy will not alleviate her arthritis pain. The toe is too short for an effective Moberg phalangeal dorsiflexion osteotomy. A Waterman first metatarsal dorsal osteotomy will not address the degenerative joint disease or shortening. Silastic arthroplasty may help, but there is the risk of additional problems with foreign body reaction and a significant risk of failure known to occur with Silastic materials.
REFERENCES: Myerson MS, Schon LC, McGuigan FX, Oznur A:Result of arthrodesis of the hallux metatarsophalangeal joint using bone graft for restoration of length. Foot Ankle Int 2000;21:297-306.
Mann RA, Coughlin MJ: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 252-253.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 293-303.

Question 39

The arrow in Figure 11 points toward a finding consistent with which of the following?

Explanation

DISCUSSION: The finding of a unilateral absent pedicle is often referred to as a winking owl sign and is a manifestation of pedicle destruction from metastatic disease. As the vertebral body is destroyed from the neoplastic process, it extends into the pedicle and destroys the cortical rim that normally creates the oval ring of the pedicle on an AP image.
REFERENCES: McLain R, Weinstein J (eds): Rothman-Simeone: The Spine, ed 4. Philadelphia, PA, WB Saunders, 1999, p 1173.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 674.

Question 40

Figures 1 and 2 are the radiographs of a 55-year-old man who has a 3-year history of right shoulder pain. He has maximized nonoperative management and is interested in operative treatment. He had an open Bankart repair 20 years ago and did well until a few years ago. What is most important to know when deciding on the best surgical treatment for this patient?

Explanation

The radiographs show severe osteoarthritis of the shoulder. The best surgical option would be an arthroplasty. The major determining factor for which type of arthroplasty to choose is the integrity of the rotator cuff tendons.
Although the radiographs do not reveal any obvious signs of rotator cuff failure, the patient had had an open Bankart 20 years ago. The integrity of the subscapularis tendon following a previous open shoulder procedure is crucial in deciding which type of arthroplasty to consider. Range of motion and infraspinatus strength do not affect the decision-making process, assuming the rotator cuff is intact. Activity level can be important when deciding whether to proceed with an arthroplasty, but it is not as important as the rotator cuff integrity when choosing which
arthroplasty to use.

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

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

Question 42

An 18-year-old football player lands on a flexed knee and ankle after being tackled. Examination reveals increased external rotation and posterior translation and varus at 30° of flexion, which decreases as the knee is flexed to 90°. What is the most likely diagnosis?

Explanation

DISCUSSION: The flexed knee and ankle mechanism of injury can result in a PCL and/or posterolateral corner injury. The examination reveals an isolated injury to the posterolateral corner (arcuate, popliteus, posterolateral capsule). This results in increased posterior translation and external rotation, as well as varus that is most notable at 30° of flexion and decreases as the knee is further flexed to 90°. Combined PCL and posterolateral corner injuries are characterized by increasing instability as the knee is flexed to 90° from 30°, while isolated PCL tears show the greatest degree of instability at 90° of flexion. A rupture of the quadriceps tendon would not affect anterior or posterior stability, whereas an isolated rupture of the lateral collateral ligament, which is a rare injury, is characterized by varus instability at 30° of knee flexion without posterior translation.
REFERENCES: Harner CD, Hoher J: Evaluation and treatment of posterior cruciate ligament injuries. Am J Sports Med 1998;26:471-482.
Veltri DM, Warren RF: Isolated and combined posterior cruciate ligament injuries. J Am Acad Orthop Surg 1993;1:67-75.

Question 43

A workers' compensation carrier for a local manufacturing company requests a second opinion on a 59-year-old man who sustained a crush injury to his foot and leg at work 6 months ago. His leg and foot were pinned between a forklift and a wall when an employee he was supervising lost control of the forklift. The employer suspects that the injured worker is malingering because the treating physician released him to work, but he has not returned to work. Which of the following elements of your history will best help you determine that the injured worker does not want to return to work out of fear of a confrontation with the employee he was supervising?

Explanation

Empathy during the interview demonstrates compassion and earns the patient's trust; which, in turn, enables the patient to discuss any agenda or concerns he or she may otherwise feel uncomfortable revealing. It is also important to engage the patient to establish a trusting relationship and thus understand all the factors impacting the patient. A formal attitude toward the patient makes it difficult to engage the patient to be "drawn in." An engaged patient is more comfortable, reliable, and thorough when providing a history. Closed-end, yes-no questions do not allow the patient to detail all of the subtle nuances of their condition and its effect on their life. Taking copious notes likewise prevents engagement of the patient and the distraction of taking notes may cause the physician to miss an important detail. It is better to lean forward in a chair when interviewing a patient because this suggests the physician is genuinely interested, whereas leaning back in a chair suggests the physician is simply waiting for the patient to finish talking. Avoid interrupting the patient when talking.

Question 44

With increasing abduction in the scapular plane, maintaining neutral rotation, contact area, and contact pressure per unit area between the humeral head and glenoid follows what pattern if the total load across the joint is held constant?

Explanation

DISCUSSION: The glenohumeral joint becomes more congruent at higher levels of abduction. As a consequence, contact area increases. As the load is spread more evenly across the joint, contact pressure per unit area decreases as long as the total load across the joint is held constant.
REFERENCES: Warner JJP, Bowen MK, Deng XH, et al: Articular contact patterns of the normal glenohumeral joint. J Shoulder Elbow Surg 1998;7:381-388.
Greis PE, Scuderi MG, Mohr A, et al: Glenohumeral articular contact areas and pressures following labral and osseous injury to the anteroinferior quadrant of the glenoid. J Shoulder Elbow Surg 2002;11:442-451.

Question 45

A 12-year-old boy sustains open comminuted midshaft tibial and fibular fractures while playing indoor soccer. The wound is grossly clean and measures 7 cm with some periosteal stripping. Antibiotics and tetanus toxoid are administered immediately in the emergency department. Following irrigation and debridement of the wound in the operating room, treatment should include

Explanation

DISCUSSION: Open fractures in children have similar rates of short-term complications such as compartment syndrome, vascular injury, and nerve injury when compared to adult fractures. Primary wound closure should be used for Gustillo and Anderson type 1 or uncomplicated type 2 fractures after surgical debridement. Skeletal stabilization may consist of external fixation, flexible nails, or casting with or without supplementary pin fixation. For an open comminuted midshaft fracture, external fixation is the treatment of choice. Reamed intramedullary nailing is contraindicated in children with an open physis. Plate fixation has a high complication rate in severe open fractures.
REFERENCES: Jones BG, Duncan RD: Open tibial fractures in children under 13 years of age-10 years experience. Injury 2003;34:776-780.
Bartlett CS III, Weiner LS, Yang EC: Treatment of type II and type III open tibia fractures in children. J Orthop Trauma 1997;11:357-362.
Robertson P, Karol LA, Rab GT: Open fractures of the tibia and femur in children. J Pediatr Orthop 1996;16:621-626.
Cullen MC, Roy DR, Crawford AH, et al: Open fracture of the tibia in children. J Bone Joint Surg Am 1996;78:1039-1047.

Question 46

A 30-year-old woman who runs approximately 30 miles a week has had right hip and groin pain for the past 3 weeks. Examination reveals an antalgic gait, limited motion of the right hip, and pain, especially with internal and external rotation. Plain radiographs are normal, and an MRI scan is shown in Figure 21. Management should consist of

Explanation

DISCUSSION: A stress fracture of the hip is a relatively common problem in endurance sports. These fractures are classified as compression-side, tension-side, and displaced femoral neck fractures. The MRI scan shows a compression-side stress fracture. Compression-side fractures usually occur in the inferior or calcar area of the proximal femur, and non-weight-bearing crutch ambulation for 6 to 7 weeks will most likely result in healing. Once the patient is walking without pain or a limp, activities can be slowly increased. Because tension-side fractures have a high risk of displacement, treatment should consist of immediate internal fixation.
REFERENCES: Griffin LY (ed): Orthopaedic Knowledge Update: Sports Medicine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 239-253.
Fullerton LR Jr, Snowdy HA: Femoral neck stress fractures. Am J Sports Med

1988;16:365-377.

Question 47

A 19-year-old soccer player feels a pop in his knee while making a cut and notes the development of an effusion over several hours. Examination reveals medial joint line tenderness, but the knee is stable to manual stress testing of all ligaments. Examination under anesthesia confirms a stable knee. What is the most critical factor in determining healing after repair of the lesion shown in Figure 14?

Explanation

DISCUSSION: Numerous clinical and basic science investigations have evaluated meniscal tear characteristics to identify factors that either promote or mitigate against meniscal healing. Complex tears have been noted to heal poorly, while longitudinal tears heal more predictably. Tear length, time from injury to repair, medial versus lateral meniscal tears, and the use of a fibrin clot have not been shown to consistently affect meniscal healing. However, rim width, the distance of the tear site from the peripheral meniscocapsular junction (vascular supply), has been shown to have a significant role in the ability of a meniscus repair to heal.
REFERENCES: DeHaven KE, Arnoczky SP: Meniscus repair: Basic science, indications for repair, and open repair. Instr Course Lect 1994;43:65-76.
Henning CE, Lynch MA, Clark JR: Vascularity for healing of meniscus repairs. Arthroscopy 1987;3:13-18.

Question 48

Figure 17 shows the clinical photograph of a 45-year-old female tennis player who has right arm pain and weakness with elevation after undergoing a cervical biopsy several months ago. The cause of her shoulder weakness is damage to the

Explanation

DISCUSSION: The patient has primary scapulotrapezius winging caused by surgical damage to the spinal accessory nerve during a lymph node biopsy. Other causes include blunt trauma, traction, and penetrating injuries. With spinal accessory palsy, the shoulder appears depressed and laterally translated because of unopposed serratus anterior muscle function. With primary serratus anterior winging that is the result of long thoracic nerve palsy, the scapula assumes a position of elevation and medial translation with the inferior angle rotated medially. The thoracodorsal nerve innervates the latissimus dorsi and is not associated with scapular winging.
REFERENCES: Kuhn JE, Plancher KD, Hawkins RJ: Scapular winging. J Am Acad Orthop Surg 1995;3:319-325.
Wright TA: Accessory spinal nerve injury. Clin Orthop 1975;109:15-18.

Question 49

5 mm of change in the atlanto-dens interval (ADI) between flexion and extension views

Explanation

The patient has been treated with agents for rheumatoid arthritis (RA) and is developing symptoms concerning for rheumatoid cervical spondylitis. All of the answers are indications for surgical intervention EXCEPT >3.5 mm change in ADI on flexion/extension views.
With the introductions of disease-modifying antirheumatic agents (DMARDs), the incidence of RA patients undergoing cervical spine surgery has decreased significantly. Basilar invagination, atlantoaxial instability, and subaxial subluxation are the three most common manifestations of cervical disease. Multiple studies in RA patients with untreated or poorly controlled disease have led to the development of a set of measurements that identify patients who require surgical intervention and predict outcome after surgery. Additionally, progressive neurological compromise and
refractory
pain
are
indications
for
intervention.
Kim and Hilibrand reviewed management of the rheumatoid cervical spine and outline parameters for surgical intervention. These include a PADI < 14 mm, cervicomedullary angle <135 degrees, progressive neurological deficit, refractory pain, atlantoaxial impaction as determined by migration >5 mm rostral to McGregor's line, and subaxial canal diameter < 14 mm.
Boden et al. analyzed 73 patients followed for rheumatoid cervical spine disease with an average follow up of 7 years. They found that the PADI correlated with paralysis. Patients with PADI less than 10 mm had no recovery, and all patients with PADI greater than 14 mm had full recovery.
Illustration A demonstrates the measurement of the ADI and PADI. Illustration B demonstrates how to measure the cervicomedullary angle (as marked by A), which is typically determined on MRI
Incorrect

Question 50

Figure 45 shows the radiograph of a 2-year-old patient who has progressive lumbar scoliosis as the result of hemivertebra. Examination reveals no associated cutaneous lesions, and an MRI scan shows no associated intraspinal anomalies. Treatment should consist of

Explanation

DISCUSSION: In a retrospective review of 10 patients treated with hemivertebra excision for hemivertebra in the levels of T12 to L3, the procedure was found to be safe and effective. The procedure provided an average curve correction of 67° and was greatest in patients who were younger than age 4 years at the time of surgery. Long anterior and posterior fusion with instrumentation is not the treatment of choice at this age. Either anterior hemiepiphyseodesis or posterior hemiarthrodesis in this isolated hemivertebra setting would be inadequate. Brace treatment is ineffective in management of the primary curvature.
REFERENCE: Callahan BC, Georgopoulos G, Eilert RE: Hemivertebral excision for congenital scoliosis. J Pediatr Orthop 1997;17:96-99.

Question 51

An ulnar nerve palsy at the level of the wrist is typically associated with deficits in the palmaris brevis, the hypothenar muscles, and what other groups of muscles?

Explanation

DISCUSSION: The intrinsic muscles innervated by the ulnar nerve include the palmaris brevis, hypothenar muscles, all of the interossei, adductor pollicis, and the deep head of the flexor pollicis brevis. The superficial head of the flexor pollicis brevis is innervated by the

median nerve.
REFERENCES: Goldfarb CA, Stern PJ: Low ulnar nerve palsy. JASSH 2003;3:14-26.
Omer G: Ulnar nerve palsy, in Green DP, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, Churchill Livingstone, 1999, pp 1526-1541.

Question 52

Which of the following mechanisms of inhibition has been linked to cigarette smoking and lumbar spinal fusion?

Explanation

DISCUSSION: Cigarette smoking has been directly linked to pseudarthrosis in spinal fusions. The direct mechanism of action is diminished revascularization of cancellous bone graft. Additionally, a smaller area of revascularization is seen in these grafts, as well as an increased area of necrosis. Increased activity of osteoblasts would result in more bone production. Increased activity of osteocytes would not affect the fusion because osteocytes are mature bone cells.
REFERENCE: Daftari TK, Whitesides TE Jr, Heller JG, et al: Nicotine on the revascularization of bone graft: An experimental study in rabbits. Spine 1994;19:904-911.

Question 53

A 13-year-old boy has pain and a firm mass in his left knee. A radiograph and MRI scan are shown in Figures 2a and 2b, and a biopsy specimen is shown in Figure 2c. Based on these findings, what is the most likely diagnosis?

Explanation

DISCUSSION: The most likely diagnosis is osteosarcoma. The imaging studies show an aggressive primary tumor of bone, and the histology slide shows a typical chondroblastic osteosarcoma, with osteoid deposited along the surface of bone trabeculae. Ewing’s sarcoma histologically consists of small round blue cells. Osteochondroma and periosteal chondroma can occur near the knee but have different radiographic and histologic patterns. Chondrosarcoma rarely occurs in children.
REFERENCES: Simon M, Springfield D, et al: Osteogenic sarcoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 267.
Wold LA, et al: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990,
pp 14-15.

Question 54

A 24-year-old baseball pitcher reports pain over the posterior aspect of his shoulder that occurs only during throwing. He notes that the discomfort is greatest during the late cocking and early acceleration phases. Examination reveals localized tenderness with palpation over the external rotators and posterior glenoid. Radiographs are shown in Figures 38a through 38c. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographs show a posterior glenoid osteophyte, often termed a “thrower’s exostosis.” These exostoses are best visualized on the Stryker notch view and may be missed on other more standard radiographic views of the shoulder. CT and MRI scans may be used, but usually add little information to the radiographic findings. Arthroscopic examination of patients with this condition commonly reveals undersurface tearing of the rotator cuff and posterior labrum. Treatment of this condition remains somewhat controversial, with avocation of both nonsurgical and surgical techniques.
REFERENCES: Meister K, Andrews JR, Batts J, Wilk K, Baumgarten T, Baumgartner T: Symptomatic thrower’s exostosis: Arthroscopic evaluation and treatment. Am J Sports Med 1999;27:133-136.
Ferrari JD, Ferrari DA, Coumas J, Pappas AM: Posterior ossification of the shoulder: The Bennett lesion. Etiology, diagnosis, and treatment. Am J Sports Med 1994;22:171-176.
Walch G, Boileau P, Noel E, et al: Impingement of the deep surface of the supraspinatus tendon on the posteriorsuperior glenoid rim: An arthroscopic study. J Shoulder Elbow Surg 1992;1:238-245.

Question 55

During total knee arthroplasty using a posterior cruciate-retaining design, excessive tightness in flexion is noted, while the extension gap is felt to be balanced. Which of the following actions will effectively balance the knee?

Explanation

DISCUSSION: Excessive flexion gap tightness can be addressed with a variety of techniques; including: (a) recess and release the posterior cruciate ligament; (b) resect a posterior slope in the tibia; (c) avoid an oversized femoral component that moves the posterior condyles more distally; (d) resect more posterior femoral condyle and use a smaller femoral component placed more anteriorly; and (e) release the tight posterior capsule and balance the collateral ligaments.
REFERENCE: Ayers DC, Dennis DA, Johanson NA, Pelligrini VD: Common complications of total knee arthroplasty. J Bone Joint Surg Am 1997;79:278-311.

Question 56

Figure 1 shows a patient with an open tibia fracture who presents to the emergency department after a propeller injury in brackish water (river water and sea water). What is the most appropriate antibiotic coverage for this patient?

Explanation

Discussion: The clinical photo shows significant soft tissue wounds with associated tibia fracture. With the amount of soft tissue damage and periosteal stripping this would be classified as a Gustilo Type IIIB injury. The brackish water environment where this particular injury occurred influences the antibiotic choice secondary to the particular organisms found in this setting. Brackish water is made up of both fresh and salt water with common organisms that include Vibrio species, Aeromonas hydrophila, Pseudomonas species, Erysipelothrix rhusiopathiae, and Mycobacterium marinum. The combination of both Doxycycline (tetracycline) and Ceftazidime (third-generation cephalosporin) cover these particular pathogens. Standard antibiotic coverage for Gustilo Type I and II injures is 1st generation cephalosporin (cefazolin), with Type III being 1st generation cephalosporin and aminoglycoside (cefazolin and gentamicin) or a fluoroquinolone. In Type III injuries, Penicillin is commonly added in barnyard injuries for extended coverage of
soil-borne pathogens (clostridial species). Vancomycin is not indicated for coverage in marine environments, rather it is more commonly used for populations with a high prevalence of nosocomial infections. Sulfamethoxazole-trimethoprim is not used for open fracture coverage.

Question 57

40A B Figures 40a and 40b are this patient's intraoperative arthroscopic images. The abnormality seen here illustrates which of the patient's clinical findings?

Explanation

DISCUSSION
Ankle sprains are the most common musculoskeletal injury; however, most of these sprains do not progress to chronic instability. Initial injuries are treated with RICE (rest, ice, compression, elevation), range of motion, weight bearing
as tolerated, and proprioceptive therapy. Lace-up ankle braces are most effective during the subacute period after a sprain. Structured physical therapy focused on proprioception is recommended for 6 weeks. Examination findings for ankle ligament instability are unreliable because of associated subtalar joint motion. Casting is not as effective as functional rehabilitation. Stress radiographs are recommended, but a clear pathologic range of measurements is not defined. Generalized ligament laxity can result in false-positive findings of instability; therefore, contralateral stress radiographs are often necessary for comparison. The difference in anterior drawer measurement between both ankles should not exceed 5mm. Likewise, the difference in talar tilt measurement between both ankles should be 5 or fewer degrees. Patients with mechanical symptoms, a joint effusion, or continued pain may have an intra-articular pathology such as a loose body or osteochondral lesion. Ankle instability can exist without ligamentous laxity. Symptoms of chronic instability can result from osteochondral lesions of talus, peroneal tendon pathology, loose bodies, anterior ankle impingement, and fracture nonunions. Although there is not sufficient evidence to recommend arthroscopy prior to all ligament reconstructions, arthroscopy is recommended when other pathology is suspected.
RECOMMENDED READINGS
Colville MR. Surgical treatment of the unstable ankle. J Am Acad Orthop Surg. 1998 Nov-Dec;6(6):368-77. Review. PubMed PMID: 9826420. View Abstract at PubMed
DiGiovanni CW, Brodsky A. Current concepts: lateral ankle instability. Foot Ankle Int. 2006 Oct;27(10):854-66. Review. PubMed PMID: 17054892. View Abstract at PubMed
Maffulli N, Ferran NA. Management of acute and chronic ankle instability. J Am Acad Orthop Surg. 2008 Oct;16(10):608-15. Review. PubMed PMID: 18832604. View Abstract at PubMed

Question 58

What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?

Explanation

DISCUSSION: Normal glenohumeral kinematics are represented by ball-and-socket modeling when the rotator cuff is intact. This is true for motion that involves more than 30 degrees of abduction. In patients with shoulder pain and symptomatic rotator cuff tears, superior translation occurs with abduction beyond 30 degrees. This is quite evident in massive tears but is seen consistently to a lesser degree with smaller tears.
REFERENCES: Yamaguchi K, Sher JS, Anderson WK, et al: Glenohumeral motion in patients with rotator cuff tears: A comparison of asymptomatic and symptomatic shoulders. J Shoulder Elbow Surg 2000;9:6-11.
Poppen NK, Walker PS: Normal and abnormal motion of the shoulder. J Bone Joint Surg Am 1976;58:195-201.

Question 59

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

Explanation

DISCUSSION: Osteofibrous dysplasia frequently presents at a very young age, usually less than 10 years. In most patients, it involves the anterior cortex of the tibial shaft and minor anterior bowing of the tibia is frequently seen. The lesion is unpredictable in nature, but local recurrence is very high in patients who undergo surgery before 15 years of age.
REFERENCES: Campanacci M, Laus M: Osteofibrous dysplasia of the tibia and fibula. J Bone Joint Surg Am 1981;63:367-375.
McCaffery M, Letts M, Carpenter B, et al: Osteofibrous dysplasia: A review of the literature and presentation of an additional 3 cases. Am J Orthop 2003;32:479-486.

Question 60

During C1-C2 transarticular screw fixation, screw misplacement is most likely to result in injury to the

Explanation

DISCUSSION: With C1-C2 transarticular screw fixation, the following structures are potentially at risk: vertebral artery, spinal cord, occiput-C1 joint, and hypoglossal nerve. The vertebral artery is most vulnerable to injury with drill misdirection or anatomic variations in the vertebral foramen. The hypoglossal nerve may be injured if the drill, tap, or screw passes too far anterior to the lateral mass of C1. This complication is extremely rare. The occiput-C1 joint may be injured if the screw trajectory is too cephalad or cranially directed; however,this scenario is very unlikely because the exposure tends to direct the screw into a caudally inclined direction. This caudal orientation has the potential to cause vertebral artery injury, especially in patients who have a large vertebral foramen in the lateral mass of C2 because of erosions (rheumatoid arthritis) or anatomic variation. CT of the vertebral foramen is recommended when C1-C2 transarticular fixation is being considered. Spinal cord injury is extremely unlikely because of the very large size of the spinal canal in the upper cervical spine; the spinal cord lies far away from the lateral masses of C1 and C2.
REFERENCES: Mueller ME, Allgower M, et al: Manual of Internal Fixation, ed 3. New York, NY, Springer-Verlag, 1991, pp 634-636.
Gebhard JS, Schimmer RC, Jeanneret B: Safety and accuracy of transarticular screw fixation C1-C2 using an aiming device: An anatomic study. Spine 1998;23:2185-2189.

Question 61

What part of the glenoid labrum has the least vascularity?

Explanation

DISCUSSION: The glenoid labrum receives its blood supply from the suprascapular, posterior humeral circumflex, and circumflex scapular arteries. The labral vessels arise from the capsular and periosteal vessels that penetrate the periphery of the labrum. The bone does not appear to be a source of vascularity. The posterior/superior and inferior labrum have a fairly robust vascular supply, whereas the anterior/superior labrum has relatively poor vascularity, which may influence the success of superior lateral repairs.
REFERENCE: Cooper DE, Arnoczky SP, O’Brien SJ, et al: Anatomy, histology and vascularity of the glenoid labrum: An anatomical study. J Bone Joint Surg Am 1992;74:46-52.

Question 62

This reporting avoids a ceiling and floor effect, where most of the respondents score either at the top or the bottom of the assessment scale.

Explanation

Which of the following statistical tools is used to determine responsiveness?
The only accurate statement is that, at 1 month, patients in group 3 are more likely to live longer than patients in group 1 and 2.
The Kaplan-Meier curve is a statistical method used in survivorship analysis to estimate survival rates at different time points. The horizontal axis depicts the time points and the vertical axis depicts the probability of survival. At a given time point, greater survivorship is demonstrated by higher values on the vertical axis.
Kocher et al. reviewed clinical epidemiology and biostatistics relevant in orthopaedic
surgery. They reported that survivorship data are typically analyzed with use of the Kaplan-Meier method. This analysis is used when the actual date of the end point is known. A survivorship curve can be plotted to illustrate the percentage of patients still alive after the intervention.
Petrie et al. reviewed statistics, terminology and the principles involved in simple data analysis, and outlines areas of medical statistics that have gained
prominence in recent years in orthopaedic papers. The authors provide an insight into some of the more common errors that occur in published orthopaedic journals and which are frequently encountered at the review stage in papers submitted to the Journal of Bone and Joint Surgery.
Figure A depicts a Kaplan-Meier curve for 3 groups of patients undergoing 3 different interventions.
Incorrect Answers:
When evaluating patient-reported outcomes in spine surgery, the Patient- Reported Outcomes Measurement Information System (PROMIS) has been found to have what differences compared to other assessment tools?
Communication failures have been associated with increased treatment costs, increased complications, and delays in patient care.
The leading cause of medical errors, wrong-site surgeries, diagnostic delays and loss to follow-up is attributed to communication errors. Studies have shown that this directly leads to increased complications, increased treatment costs, and delays in patient care. In the surgical setting, the performance of the pre-surgical time-out affords clarification of the treatment plan, confirmation of the procedure and site, and an opportunity for the team to address any concerns.
Weller et al. reviewed barriers to effective teamwork in healthcare delivery. They found that effective communication across all team members, inclusive training, and the creation of democratic teams can reduce treatment delays and minimize complications. They concluded that all team members should have a shared understanding of the situation when involved in patients care.
Lingard et al. performed a prospective study determining the feasibility of a preoperative 10-item checklist discussion including nurses, surgeons, and anesthesiologists. They reported that the discussion usually took place prior to bringing the patient to the OR and took on average 3.5 minuted. Overall, the guided discussion was very well received by participants and provided an opportunity to inform providers of the patient's information to address potential problems. The authors cited that variations in workflow patterns as a potential barrier to widescale implementation of the checklist discussion.
Incorrect answers:
The outcomes of three novel interventions are investigated and the preliminary results are depicted in Figure A. Which of the following statements is most accurate?
Linezolid acts to inhibit protein synthesis by preventing the formation of the initiation complex between the 30S and 50S subunits of the ribosome.
Linezolid is a type of oxazolidinone, a relatively newer class of antibiotics that are active against multidrug-resistant staphylococci, streptococci, and enterococci. Although many antimicrobial agents affect or disrupt protein synthesis in bacteria, linezolid is unique in that it disrupts protein synthesis at its origin rather than later in the cascade. It achieves this by binding to the
50S subunit of the bacterial ribosome, preventing the formation of the initiation complex.
Swaney et al. performed a study to investigate the mechanism of action of linezolid. They found that linezolid inhibits the formation of the initiation complex in bacterial translation systems by preventing the formation of the N- formylmethionyl-tRNA-ribosome-mRNA ternary complex.
Thompson et al. performed a study on the efficacy of various antibiotics in treating periprosthetic joint infections (PJI). They administered oral linezolid with or without oral rifampin, intravenous vancomycin with oral rifampin, intravenous daptomycin or ceftaroline with or without oral rifampin, oral doxycycline, or sham treatment at human- exposure doses for 6 weeks in a mouse model of PJI. They found that oral-only linezolid-rifampin and all intravenous antibiotic-rifampin combinations resulted in no recoverable bacteria and minimized reactive bone changes. Additionally, although oral linezolid was found to be the most effective monotherapy, all oral and intravenous antibiotic monotherapies failed to clear infection or prevent reactive bone changes.
They concluded that the oral-only linezolid-rifampin option might reduce venous access complications and health-care costs.
Illustration A is a diagram depicting the mechanism of action of various antibiotics.
Incorrect Answers:
50S subunit of the bacterial ribosome, preventing protein chain elongation by inhibiting peptidyl transferase activity of the ribosome.
elongation by blocking aminoacyl translocation.
Failure of effective communication in the surgical setting has been associated with what?
Unfractionated heparin works in the coagulation cascade by promoting the ability of antithrombin III to inhibit factors IIa, III, Xa.
Heparin works by binding to and enhancing the ability of antithrombin III to inhibit factors IIa, III, Xa. It is metabolized by the liver. The risks associated with the use of unfractionated heparin include bleeding and heparin induced thrombocytopenia (HIT). The reversal agent is protamine sulfate.
Agnelli et al. reviewed direct thrombin inhibitors for the prevention of VTE after major orthopaedic surgery. They reported widespread use, however, limitations in the use of unfractionated heparin and low-molecular-weight heparins. They highlighted that direct thrombin inhibitors (Ximelagatran) inactivate thrombin without requiring any plasma cofactor, inhibit both free
and fibrin-bound thrombin, and do not appreciably bind to plasma proteins. They concluded that the features of rapid absorption, conversion, bioavailability, low variability, dose-time, food independency, and the predictable anticoagulant activity make direct thrombin inhibitors an attractive antithrombotic agent especially for prolonged out-of hospital prophylaxis.
Kwong et al. reviewed the efficacy and safety of fondaparinux, a selective factor Xa inhibitor and reported its efficacy and safety in 4 phase III clinical trials. They reported fondaparinux usage resulted in an overall 55% decrease in the risk of venous thromboembolism (VTE) relative to the low-molecular- weight heparin enoxaparin without increasing the incidence of clinically relevant bleeding, which was similarly low for both agents. They concluded
that the superior efficacy of fondaparinux relative to enoxaparin is the result of its unique mechanism of action, clinical pharmacology.
McLynn et al. investigated the risk factors and chemoprophylaxis for VTE in elective spine surgery. They reported that independent risk factors for VTE included greater age, male gender, increasing body mass index, dependent functional status, lumbar spine surgery, longer operative time, perioperative blood transfusion, longer length of stay, and other postoperative
complications. The majority of patients received unfractioned heparin and they observed this did not significantly influence the rate of VTE, but was associated with a significant increase in hematoma requiring a return to the operating room. They concluded that there is insufficient evidence to support the routine use of chemoprophylaxis in low-risk patients, and recommended full consideration of risks and benefits after elective spine surgery.
Figure A depicts the coagulation cascade, with the factor circled in red (IIa) being the target of unfractionated heparin, through its effect on antithrombin III.
Incorrect Answers:
Which of the following antibiotics acts to inhibit protein synthesis by preventing the formation of the initiation complex between the 30S and 50S subunits of the ribosome?
Acetaminophen inhibits prostaglandin E2 production through its effect on interleukin-1 beta. It exerts its effects on the central nervous system.
Multimodal pain management has become an increasingly important consideration in total joint arthroplasty recovery, namely in regard to minimizing opioid requirements while optimizing pain control and patient satisfaction. Given the negative side effects and increasing scrutiny on narcotic use, modalities that help to decrease post-operative narcotic requirements have become a major focus and include nonsteroidal anti- inflammatories, selective COX-2 inhibitors, gabapentinoids, local anesthetic blocks, and acetaminophen. Acetaminophen acts directly the central nervous system, providing both pain relief and antipyretic effects. It does so by inhibiting prostaglandin E2 production through the blockade of interleukin-1 beta.
Jinnah et al. performed a comparison of two multimodal pain regimens used for postoperative pain control in total joint arthroplasty patients. They hypothesized that using a multimodal pain protocol focusing on periarticular injections including liposomal bupivacaine would have improved results when compared with a parenteral opioid- based regimen. They found a decrease in length of stay and rate of discharge to skilled nursing facilities with the implementation of a novel multimodal protocol. They concluded that a multimodal approach inclusive of periarticular injection can lead to a reduced
length of stay.
Politi et al. performed a prospective randomized trial comparing the use of intravenous versus oral acetaminophen in total joint arthroplasty. They found that IV acetaminophen did not provide a significant difference in pain relief except within the first 0-4 hours. They concluded that IV acetaminophen does not provide a significant benefit when compared to the oral form, which is also less expensive.
Incorrect Answers:
Which of the following agents results in blood anticoagulation by exerting inhibitory effects on the factor circled in the color red in Figure A?
Based on the stress-strain curve in Figure A, ceramic has the highest modulus of elasticity.
Young's modulus is a measure of the stiffness (ability to resist deformation) of a material in the elastic zone that is calculated by measuring the slope of the stress-strain curve in the elastic zone. A higher modulus of elasticity indicates a stiffer material. Relative values of Young's modulus include: (1) ceramic, (2) alloy, (3) stainless steel, (4) titanium, (5)
cortical bone, (6) matrix polymers, (7) PMMA, (8) polyethylene, (9) cancellous bone, (10) tendon/ligaments, and (11) cartilage.
Lang et al. published a review on the use of ceramics in total hip replacement. They report that properties of ceramic which make it particularly attractive for this application include its hardness, high compression strength, and excellent wettability. However, its low fracture toughness and linear elastic behavior make it prone to breakage under stress.
Figure A is a stress-strain curve, the slope of which is used to determine Young's modulus.
Incorrect Answers:
Which of the following medications work by inhibiting prostaglandin E2 production through interleukin-1 beta?
A power analysis determines the minimum number of patients needed in a study to show a clinically significant difference. It should be performed before starting the study.
Power is the probability of finding a significant association if one truly exists. It is defined as 1 minus the probability of a type 2 error (beta) and is generally set to 80% meaning that we are willing to accept a 20% chance of a type 2 error. A power analysis will determine the minimum number of patients that shows a clinically significant difference. The minimum number of patients should be determined prior to initiating a study. Calculation of power after a study has been completed is controversial and discouraged.
Vavken et al. performed a review on the management of confounding in controlled orthopaedic trials. They report that confounding occurs when the effect of exposure of an outcome is distorted by a confounding factor and will lead to spurious effect estimates in clinical studies. They performed a cross- sectional study of a sample of controlled trials reported in the orthopaedic literature in 2006. They conclude that only 30 studies reported that the had a power analysis performed.
Kocher et al. performed a review of clinical epidemiology and biostatistics as a primer for orthopedic surgeons. They report that a power analysis should be performed prior to initiating the study. This will ensure the study is appropriately powered and decrease the effects of chance. They conclude that when a study determines no significant effect the power of the study should be reported.
Incorrect Answers:
Based on the stress-strain curve in Figure A, which of the following materials has the highest modulus of elasticity?
The World Health Organization (WHO) defines osteopenia as a bone mineral density (BMD) that is between 1 and 2.5 standard deviations below young normal (T-score of - 1 to -2.5).
The WHO defines osteopenia as decreased BMD without fracture risk. Osteopenia is defined as a T-score of 1 to 2.5 standard deviations below young normals (-1 to -2.5), while osteoporosis is defined as a T-score of more than

Question 63

A 5-year-old girl sustains an isolated injury to the right shoulder area after falling off the monkey bars. Examination reveals intact neurovascular function in the extremity distally, but she is quite uncomfortable. An AP radiograph of the proximal humerus is shown in Figure 24. Her parents state that she is a very talented gymnast. Considering her age and potential athletic career, management should consist of

Explanation

DISCUSSION: In this age group, bayonet apposition can produce very good results. Healing occurs rapidly, and remodeling usually is complete in less than 1 year. All of the other methods have significant risks of complications and are unnecessary for this fracture.
REFERENCES: Martin RF: Fractures of the proximal humerus and humeral shaft, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994,

pp 144-148.
Sanders JO, Rockwood CA Jr, Curtis RJ: Fractures and dislocation of the humeral shaft and shoulder, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 937-939.

Question 64

What nerve is most at risk during placement of the anterolateral portal in elbow arthroscopy?

Explanation

DISCUSSION: The radial nerve is only 4 mm from the anterolateral portal, while the median nerve is 11 mm away from the anteromedial portal. The ulnar nerve is only at risk on the medial side of the elbow. Anterior and posterior interosseous nerves are more distal within the forearm and are not in danger during portal placement.
REFERENCES: O’Driscoll SW, Morrey BF: Elbow arthroscopy, in Morrey BF (ed): The Elbow. Philadelphia, PA, Lippincott, Williams and Wilkins, 1994, pp 21-34.
Field LD, Altchek DW, Warren RF, O’Brien SJ, Skyhar MJ, Wickiewicz TL: Arthroscopic anatomy of the lateral elbow: A comparison of three portals. Arthroscopy 1994;10:602-607.

Question 65

A 15-year-old wrestler sustains an abduction, hyperextension, and external rotation injury to his right shoulder. The MRI scan findings shown in Figures 27a and 27b are most consistent with Review Topic

Explanation

An isolated avulsion of the lesser tuberosity occurs very rarely and usually is found in 12- and 13-year-old adolescents. The MRI scans reveal a tear of the humeral attachment of the inferior glenohumeral ligament, a so-called HAGL lesion. This injury to the inferior glenohumeral ligament occurs much less commonly than the classic Bankart lesion (anterior inferior labral tear). A tear of the subscapularis occurs with a similar mechanism of injury but generally occurs in older individuals.

Question 66

Figures below show the radiographs, and the CT obtained from a 58-year-old woman who underwent cementless left total hip arthroplasty. Nine months after surgery, she continued to have groin pain when actively flexing her hip. She has trouble walking up stairs and getting out of her car. What is the most likely diagnosis?

Explanation

DISCUSSION:
Groin pain after total hip replacement has a number of possible causes, and an exact diagnosis may remain elusive in some patients. Infection should be ruled out with laboratory studies and, if indicated, diagnostic aspiration of the hip joint. Implant loosening should be evaluated by plain radiograph and bone scan, if indicated. Synovitis resulting from wear debris should be considered in patients with polyethylene liners who experience late-onset symptoms or in any patient with a metal-on-metal bearing. This patient's symptoms are classic for iliopsoas tendonitis. Physical examination usually reveals pain and weakness with resisted hip flexion. A cross-table lateral radiograph and CT show that the anterior edge of the acetabulum protrudes beyond the anterior wall, thereby acting as a source of iliopsoas tendon irritation. In such cases, acetabular component revision and repositioning are indicated. Fluoroscope-guided iliopsoas cortisone injection can help to establish the diagnosis and relieve groin pain. If the acetabular component is well positioned, then iliopsoas tenotomy should be considered.

Question 67

A 47-year-old man is seen in consultation in the ICU after being admitted and treated emergently for a dissecting aortic aneurysm. Current examination reveals generalized weakness of the lower extremities with a significant decrease in pain and temperature sensation from approximately the waist down. Proprioception is maintained. What is the most likely diagnosis at this time? Review Topic

Explanation

Incomplete cord syndromes include anterior cord syndrome, Brown-Sequard syndrome, central cord syndrome, and posterior cord syndrome. The anterior cord syndrome involves a variable loss of motor function and pain and/or temperature sensation, with preservation of proprioception as seen in this patient. The Brown-Sequard syndrome involves an ipsilateral loss of proprioception and motor function, with contralateral loss of pain and temperature sensation. The posterior cord syndrome is a rare injury and is characterized by preservation of motor function, sense of pain and light touch, with loss of proprioception and temperature sensation below the level of the lesion. The central cord syndrome is characterized with greater motor weakness in the upper extremities than in the lower extremities. The pattern of motor weakness shows greater distal involvement in the affected extremity than proximal muscle weakness. Spinal shock is the period of time, usually 24 hours, after a spinal injury characterized by absent reflexes, flaccidity, and loss of sensation below the level of the injury.

Question 68

Figures 1 and 2 are the radiographs of a 24-year-old male wrestler who underwent surgery for recurrent shoulder dislocations using coracoid autograft. At his first postoperative visit, the patient complains of decreased sensation on the lateral aspect of his forearm. The patient’s symptoms are most likely due to injury of the

Explanation

The patient has undergone a Latarjet procedure as shown in the radiographs. After harvesting the coracoid graft, care must be taken to not place too much tension on or dissect excessively near the musculocutaneous nerve. The nerve is encountered 5 cm distal to the coracoid as it enters the conjoint tendon. The lateral antebrachial cutaneous nerve is the terminal branch of the musculocutaneous nerve and; therefore, injury can cause decreased sensation in the lateral forearm.

Question 69

A 16-year-old girl has had anterior leg pain and a mass for the past 8 months. Figures 2a and 2b show a radiograph and an H & E histologic specimen. Which of the following disorders is believed to be a precursor of this lesion?

Explanation

DISCUSSION: The radiograph and pathology are consistent with adamantinoma. While the mechanism underlying adamantinoma has not been identified, it is believed to be closely related to osteofibrous dysplasia, which may represent a precursor. The other diagnoses are not known to give rise to adamantinoma.
REFERENCE: Springfield DS, Rosenberg AE, Mankin HJ, et al: Relationship between osteofibrous dysplasia and adamantinoma. Clin Orthop 1994;309:234-244.

Question 70

A 45-year-old man is seen in the emergency department after returning from a 2-hour airplane flight. He is reporting severe pain in his right leg but has no trouble moving his ankle, leg, or knee. Venous doppler testing reveals no evidence of deep venous thrombosis. He is placed on IV cephazolin but continues to worsen. On the third day in the hospital he has increased pain, some respiratory distress, and trouble maintaining his blood pressure. His leg takes on the appearance seen in Figure 15. An urgent MRI scan shows thickening of the subcutaneous tissues and superficial swelling in the leg but no evidence of an abscess. What is the next most appropriate step in management? Review Topic

Explanation

The patient has necrotizing fasciitis, a rare and sometimes fatal disease that has many different etiologies. Signs that this is not a normal infection are the worsening clinical symptoms despite IV antibiotics and the systemic symptoms. He needs urgent surgical care before he becomes completely septic and unstable. He needs very aggressive debridement of his tissues. Hyperbaric oxygen and immunoglobulins are only anecdotally helpful, and would only be used after surgery.

Question 71

A 66-year-old man has a high-grade angiosarcoma of the right tibia. A radiograph is shown in Figure 43. Treatment should consist of

Explanation

DISCUSSION: Angiosarcoma is a locally aggressive sarcoma. The radiograph shows extensive multiple discontinuous lesions throughout the entire tibia. The extent of bone involvement precludes resection; therefore, the treatment of choice is amputation, either above the knee or through the knee. Radiation therapy is not needed after amputation, and chemotherapy remains investigational for soft-tissue sarcoma.
REFERENCE: Simon MA, Springfield DA: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott-Raven, 1998, ch 29.

Question 72

What is the primary reason for including the ilium in the distal fixation of long instrumentation constructs in adult scoliosis?

Explanation

DISCUSSION: Studies have shown that when compared with fixation to the sacrum alone, the success rate of fusion across the lumbosacral junction increases when both the sacrum and ilium are included in the posterolateral construct. Curve correction, coronal balance, and pelvic balance are all attended to within the thoracolumbar spine and are not directly related to the pelvic fixation. Fretting and corrosion are a byproduct of metal-to-metal connections.
REFERENCES: Islam NC, Wood KB, Transfeldt EE, et al: Extension of fusions to the pelvis in idiopathic scoliosis. Spine 2001;26:166-173.
Emami A, Deviren V, Berven S, et al: Outcome and complications of long fusions to the sacrum in adult spine deformity: Luque-Galveston, combined iliac and sacral screws, and sacral fixation. Spine 2002;27:776-786.

Question 73

What tendon has an intra-articular (instrasynovial) location in the knee joint?

Explanation

DISCUSSION: The popliteal tendon arises from the posterior aspect of the tibia and courses through the knee joint through the popliteus hiatus of the lateral meniscus before attaching on the lateral femur anterior to the lateral collateral ligament. It is the only tendon in the knee joint that can be viewed directly on arthroscopy.
REFERENCES: Kimura M, Shirakura K, Hasegawa A, Kobayashi Y, Udagawa E: Anatomy and pathophysiology of the popliteal tendon area in the lateral meniscus: 1. Arthroscopic and anatomical investigation. Arthroscopy 1992;8:419-423.
Arnoczky SP, Skyhar MJ, Wickiewicz TL: Basic science of the knee, in McGinty JB (ed): Operative Arthroscopy. New York, NY, Raven Press, 1991, pp 155-182.

Question 74

A 77-year-old woman who underwent total knee arthroplasty 16 years ago now reports pain, swelling, and notable crepitation with range of motion. AP, lateral, and Merchant radiographs are shown in Figures 54a through 54c. What is the most likely diagnosis?

Explanation

DISCUSSION: The Merchant radiograph shows a lateral patellar shift with total polyethylene failure, resulting in a metal-on-metal bearing. This problem is associated with metal-backed patellar components. Component fixation appears solid, and no osteolysis is evident.
REFERENCES: Poss R (ed): Orthopaedic Knowledge Update 3. Park Ridge, IL, American Academy of Orthopaedic Surgeons, 1990, pp 590-593.
Leopold SS, Berger RA, Patterson L, et al: Serum titanium level for diagnosis of a failed metal-backed patellar component. J Arthroplasty 2000;15:938-943.
Frymoyer JW (ed): Orthopaedic Knowledge Update 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1993, pp 613-614.

Question 75

.What is the most appropriate treatment if instability is present at the time of evaluation?

Explanation

Question 76

Which of the following findings helps to distinguish between stress fractures of the tibia and shin splints?

Explanation

images with tibial stress fractures.
After activity, pain persists longer with tibial stress fractures.
DISCUSSION: Anterior tibial pain can often be difficult to diagnose. A bone scan showing the tibial cortex in a diffuse, longitudinal orientation is consistent with shin splints compared to a more discreet, localized uptake more commonly seen with a stress fracture. Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but are also seem in otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patient’s history of increased physical activity and on imaging findings.
The general symptom of a bone stress injury is stress-related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis. If the diagnosis is made early, most bone stress injuries heal well without complications.
REFERENCES: Mubarak SJ, Gould RN, Lee YF, et al: The medial tibial stress syndrome: A cause of shin splints. Am J Sports Med 1982;10:201-205.
Knobloch K, Yoon U, Vogt PM: Acute and overuse injuries correlated to hours of training in master running athletes. Foot Ankle Int 2008:29:671-676.
Kiuru MJ, Pihlajamaki HK, Ahovuo JA: Bone stress injuries. Acta Radiol 2004;45:317-326.

Question 77

Figures 1 and 2 display the radiographs obtained from a woman who had volar plating of the distal radius 8 months earlier. Two days ago, she noticed she could not actively extend her thumb. What is the most appropriate treatment that would restore active thumb extension?

Explanation

EXPLANATION:
Although the fracture is aligned in anatomic position, prominence of a least one of the distal screws is evident on the lateral radiographic view. The prominent screw is the most likely cause of the EPL tendon rupture. If the patient chooses surgical treatment, the best option would be removal of the offending hardware combined with extensor indicis proprius to EPL tendon transfer. Intercalary grafting would also be an acceptable option. If the tendon transfer were to be performed alone, the prominent screw(s) could rupture the transferred tendon as well. Also, it is rarely possible to repair the EPL tendon primarily in such cases, because this rupture is an attrition type. Casting would obviously not provide any benefit in this situation, and IP arthrodesis would not be the first surgical treatment option. This problem can be avoided by using shorter screws or not placing screws in plate holes that direct screws into the third dorsal extensor compartment. Intraoperative fluoroscopy and special views, such as the carpal shoot-through view, are useful for avoiding this complication.

Question 78

Figures 1 through 5 show the radiographs obtained from a 37-year-old man who has a 10-year history of right, ulnar-sided wrist pain and a volar ulnar prominence with wrist supination. Approximately 20 years ago, he had a forearm injury that was definitively treated in a long arm cast. What surgical treatment option is most likely to improve his symptoms and maintain pronosupination?

Explanation

EXPLANATION:
The patient sustained a radial shaft fracture with subsequent apex volar malunion. As a result, his distal ulna subluxates volarly with wrist supination. Radiographs of the wrist reveal minimal arthritic changes. The most appropriate treatment option is to surgically correct his radial shaft malunion, which would indirectly address his DRUJ instability. A DRUJ ligament reconstruction or triangular fibrocartilage complex repair could be used to augment DRUJ stability; however, they might be unnecessary after correction of the radial shaft malunion. A DRUJ ligament reconstruction alone would not achieve stability of the DRUJ joint and maintain full wrist pronosupination. An ulnar head implant arthroplasty would not be reliable in eliminating the instability or the pain. Similarly, a one-bone forearm procedure might
improve the patient's pain and instability but at the cost of abnormal wrist and forearm mechanics and kinematics.

Question 79

98 degrees (range, 0 degrees to 9 degrees). In knees with varus joint lines

Explanation

Question 80

Which of the following mechanisms of inhibition has been linked to cigarette smoking and lumbar spinal fusion?

Explanation

Question 81

A 40-year old man has limited, painful motion in dorsiflexion at the metatarsophalangeal (MTP) joint of the right great toe, despite nonsurgical treatment. Radiographs show dorsal and medial osteophytes and minimal narrowing of the articular space. Treatment should consist of

Explanation

Cheilectomy, the excision of an irregular osseous rim that interferes with motion of a joint was performed on the distal part of the metatarsal of patients who had hallux rigidus. In this study by Mann, published in JBJS 1988, they were able to conclude that cheilectomy is a better method of treatment for hallux rigidus than arthrodesis, resection arthroplasty, or arthroplasty with the use of a flexible implant. In older adults who present late, with more severe X-Ray changes, Keller procedure is indicated.

Question 82

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

Explanation

DISCUSSION: Because the radiograph shows that the femoral stem is loose within the femoral canal and there is a fracture in the distal cement mantle, the stem should be revised. The Ogden-type plate and the allograft bone plates will reconstruct the femur but will not restore stability to the stem. Similarly, traction may allow the femur to heal but will not restore stability to the femoral stem within the femur. Resection arthroplasty is considered a salvage option following failure of the other procedures.
REFERENCES: Lewallen DG, Berry DJ: Periprosthetic fracture of the femur after total hip arthroplasty: Treatment and results to date, in Cannon WD Jr (ed): Instructional Course Lectures 47. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 243-249.
Bethea JS, DeAndrade JR, Fleming LL, Lindenbaum SD, Welch RB: Proximal femoral fractures following total hip arthroplasty. Clin Orthop 1982;170:95-106.

Question 83

Which of the following represents a contraindication for interspinous process decompression for the treatment of lumbar spinal stenosis? Review Topic

Explanation

Kondrashov and associates noted stable good outcomes at 4 years in 14 of 18 patients treated with X-STOP interspinous process decompression as defined as an improvement over preoperative Oswestry scores of 15 points or more. Similar results were seen after 1 year in a European study by Siddiqui and associates. Exclusion and inclusion criteria for these studies varied somewhat, but cauda equina syndrome was the only exclusion criteria listed in both studies. All of the other choices did not represent exclusion criteria in either study.

Question 84

A 14-year-old girl has had progressive heel pain for the past several months. Based on the radiograph, MRI scan, and biopsy specimens shown in Figures 37a through 37d, treatment should include

Explanation

DISCUSSION: An aneurysmal bone cyst is a benign, locally destructive lesion of bone. Most are seen in patients in the second decade of life. The clinical presentation varies, but most patients have pain, tenderness, swelling, and/or pathologic fracture. Radiographs show a radiolucent lesion sometimes with expansile remodeling of the cortex. MRI best detects the commonly seen fluid-fluid levels associated with this lesion. Histologic findings include

blood-filled spaces with bland fibrous connective tissue septa. The stroma has histiocytes, fibroblasts, scattered giant cells, hemosiderin, and occasional inflammatory cells. Treatment of these lesions consists of extended curettage, plus or minus the use of adjuvants (liquid nitrogen, phenol, argon beam coagulation), and finally filling the bone void (allograft or other bone substitute).
REFERENCES: Gibbs CP Jr, Hefele MC, Peabody TD, et al: Aneurysmal bone cyst of the extremities: Factors related to local recurrence after curettage with a high-speed burr. J Bone Joint Surg Am 1999;81:1671-1678.
Ramirez AR, Stanton RP: Aneurysmal bone cyst in 29 children. J Pediatr Orthop 2002;22:533-539.

Question 85

A construction worker sustained a comminuted calcaneus fracture 2 years ago. He now reports progressive hindfoot pain with the recent onset of anterior ankle pain. A lateral hindfoot radiograph is shown in Figure 31. Treatment should consist of

Explanation

DISCUSSION: The patient has subtalar arthrosis, a loss of heel height with anterior ankle impingement. The mechanics of the ankle are impaired, and dorsiflexion is painful and limited. The talar declination angle is measured by drawing a line through the longitudinal axis of the talus and the plane of support of the foot on a weight-bearing lateral radiograph. Anterior impingement is suggested with any value below 20 . By performing a distraction arthrodesis through the subtalar joint, the normal declination of the talus is reestablished, eliminating the anterior ankle impingement. Tibiotalocalaneal fusion would be inappropriate because the patient does not have arthritic symptoms in the ankle. Ankle arthroscopy or in situ arthrodesis would not reestablish appropriate ankle mechanics, and the osteophytes would be prone to redevelop. Lateral wall ostectomy may help with impingement at the level of the fibula or the lateral ankle but would provide no benefit to anterior ankle impingement.
REFERENCES: Carr JB, Hansen ST, Benirschke SK: Subtalar distraction bone block fusion for late complications of os calcis fractures. Foot Ankle 1988;9:81-86.
Myerson M, Quill GE Jr: Late complications of fractures of the calcaneus. J Bone Joint Surg Am 1993;75:331.

Question 86

As reflected by the SF-36 scores, patients with which of the following conditions demonstrate the most disability in physical function?

Explanation

DISCUSSION: Pollak and associates found that the average SF-36 score for patients who sustained a pilon fracture was significantly lower than patients with diabetes mellitus, AIDS, hypertension, asthma, migraines, pelvic fracture, polytrauma, and AMI. Moreover, patients having undergone pilon fixation scored lower on all but three of the SF-36 scales (vitality, mental health, and emotional health).
REFERENCE: Pollak AN, McCarthy ML, Bess RS, et al: Outcomes after treatment of high-energy tibial plafond fractures. J Bone Joint Surg Am 2003;85:1893-1900.

Question 87

During total shoulder replacement for rheumatoid arthritis, fracture of the humeral shaft occurs. An intraoperative radiograph shows a displaced short oblique fracture at the tip of the prosthesis. At this point, the surgeon should

Explanation

DISCUSSION: The risk of intraoperative fracture in osteopenic rheumatoid bone is significant. Fractures may occur with dislocation of the head and canal reaming, especially while extending and externally rotating the shoulder. If the fracture occurs at the distal tip of the prosthesis, the use of a long-stemmed prosthesis to bypass the fracture site and supplementation with wire cables has been reported with good results.
REFERENCES: Wright TW, Cofield RH: Humeral fractures after shoulder arthroplasty. J Bone Joint Surg Am 1995;77:1340-1346.
Boyd AD Jr, Thornhill TS, Barnes CL: Fractures adjacent to humeral protheses. J Bone Joint Surg Am 1992;74:1498-1504.
Petersen SA, Hawkins RJ: Revision of failed total shoulder arthroplasty. Orthop Clin North Am 1998;29:519-533.

Question 88

Figures 87a and 87b are the radiographs of an 18-year-old pedestrian who was struck by a car. During intramedullary nailing, it is difficult to maintain proper alignment. Poller blocking screws placed in the proximal fragment at which position(s) relative to the nail can help prevent the typical deformity?

Explanation

This is a proximal one third tibial shaft fracture. Typically nailing of this fracture creates a valgus and procurvatum malalignment that must be addressed. This can be difficult when using an intramedullary nail in the wide metaphyseal bone of the proximal tibia. To help direct and center the nail in the metaphysis, blocking screws can be used. Blocking screws should be placed where the nail should not travel. If the nail was passed with the proximal fragment in this position, it would occupy the lateral and posterior aspects of the metaphyseal fragment. To prevent this, blocking screws should be placed in the lateral and posterior aspects of the proximal fragment.

Question 89

Figure 62a and Figure 62b

Explanation

DISCUSSION
Figure 58 reveals a posttraumatic valgus deformity. Correction of valgus with lateral soft-tissue release places tension on the peroneal nerve, resulting in an increased risk for nerve palsy. Figures 59a (lateral view) and 59b (Merchant view) illustrate juvenile rheumatoid arthritis with tibiofibular fusion and lateral patellar dislocation. Chronic patellar dislocation is associated with contracture of the lateral retinacular soft tissues and increased risk for patellar subluxation or dislocation after TKA. Extensor mechanism realignment, possibly including tibial tubercle osteotomy and/or proximal soft-tissue realignment, may be required during TKA to centralize the extensor mechanism. Figures 60a (anteroposterior [AP] view) and 60b (lateral view) reveal a fused knee in full extension.
TKA after fusion is associated with multiple complications including skin necrosis, infection, and instability. The skin is contracted because of limited knee motion and has multiple scars (Figure 60c). Mobilization of the skin during and after knee arthroplasty can place excess tension on the soft tissues, resulting in skin necrosis and infection. Treatment consisting of prompt debridement and soft-tissue coverage, usually with medial gastrocnemius muscle transposition, is required. Figure 61 shows a knee with prior tibial tubercle fixation and marked patella infera. Shortening of the patellar ligament is associated with restricted knee motion. This may necessitate more extensile exposure using tibial tubercle osteotomy or rectus snip during TKA to obtain adequate surgical exposure. The inferior position of the patella can cause impingement between the patellar component and tibial insert, resulting in anterior knee pain. Restoring a more normal position of the patella may necessitate distal positioning of the femoral component as well as tibial tubercle osteotomy with proximal recession of the osteotomized tibial tubercle. Figures 62a (AP view of the distal femur) and 62b (AP view of the proximal femur) show a posttraumatic deformity with a large retained intramedullary rod. There is a varus distal femoral deformity that is not severe enough to necessitate extra-articular corrective osteotomy. However, intramedullary hardware precludes use of conventional intramedullary instrumentation, so computer navigation or patient-specific cutting guides will be necessary to orient the bone cuts and avoid implant malalignment.

Question 90

The best candidate for a reverse total shoulder arthroplasty is a patient with rotator cuff tear arthropathy with Review Topic

Explanation

Reverse total shoulder arthroplasty is relatively contraindicated in patients with acromial stress fractures and rheumatoid arthritis. A patient with active forward elevation to 130 degrees is better treated with a hemiarthroplasty because the motion already exceeds the average forward elevation attained in most studies using the reverse prosthesis. A centered case of rotator cuff tear arthropathy is also better treated with a hemiarthroplasty, especially in patients with a large external rotation lag sign because the reverse prosthesis has been shown to decrease active external rotation. However, hemiarthroplasties have not performed well in patients with anterior superior escape and in this group of patients, the reverse prosthesis is best.

Question 91

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

Explanation

DISCUSSION: Complications of thermal capsule shrinkage or accelerated rehabilitation include capsule ablation. Since the original surgery did not include labral reattachment, findings of a Bankart lesion or a glenoid fracture from a nontraumatic injury are unlikely. Subscapularis detachment or biceps subluxation is a postoperative complication of open repairs. Failure of early postoperative instability treatment should not produce loose bodies.
REFERENCES: Abrams JS: Thermal capsulorrhaphy for instability of the shoulder: Concerns and applications of the heat probe. Instr Course Lect 2001;50:29-36.
Hecht P, Hayashi K, Lu Y, et al: Monopolar radiofrequency energy effects on joint capsular tissue: Potential treatment for joint instability. An in vivo mechanical, morphological, and biochemical study using an ovine model. Am J Sports Med 1999;27:761-771.

Question 92

Figures 3a and 3b show the MRI scans of a patient with neck pain. What is the most likely diagnosis?

Explanation

DISCUSSION: Muliple neurofibromas result in marked foraminal enlargement as seen on the sagittal MRI scan. Collagen disorders leading to dural ectasia may show similar enlargement, but none of these is listed as a possible answer.
REFERENCES: Kim HW, Weinstein SL: Spine update: The management of scoliosis in neurofibromatosis. Spine 1997;22:2770-2776.
Funasaki H, Winter RB, Lonstein JB, et al: Pathophysiology of spinal deformities in neurofibromatosis: An analysis of seventy-one patients who had curves associated with dystrophic changes. J Bone Joint Surg Am 1994;76:692-700.

Question 93

A 21-year-old football player who sustained a direct blow to the posterior hindfoot while making a cut is unable to bear weight on the injured foot. Examination reveals tenderness and swelling of the great toe metatarsophalangeal (MTP) joint. Radiographs are shown in Figures 9a and 9b. What is the most likely diagnosis?

Explanation

DISCUSSION: Turf toe occurs in collision and contact sports in which the athlete pushes off to accelerate or change direction and there is hyperextension of the great toe MTP joint. Typically, there is also axial loading of the posterior hindfoot, which increases the hyperextension of the MTP joint. The most common presentation is pain and swelling of the MTP joint and inability to hyperextend the joint without significant symptoms. With significant force, fractures of the sesmoids and plantar soft tissues can occur. The radiographs do not show a dislocation of the great toe MTP joint because it is concentrically located on both radiographs. However, the radiographs show a fracture of the lateral sesamoid or a diastasis of a bipartite lateral sesamoid. The medial sesamoid is also proximal indicating a rupture of the plantar (volar) plate. Therefore, the most likely diagnosis is a fracture of the lateral sesamoid with rupture of the plantar plate leading to proximal migration of the proximal fragment of the lateral sesamoid and the medial sesamoid.
REFERENCES: Rodeo SA, et al: Diastasis of bipartite sesamoids of the first metatarsophalangeal joint. Foot Ankle 1993;l4:425-434.
Rodeo SA, O’Brien S, Warren RF, et al: Turf toe: An analysis of metatarsal joint sprains in professional football players. Am J Sports Med 1990;18:280-285.

Question 94

Deep anterior compartment

Explanation

How many compartments exist in the foot:

Question 95

During total hip arthroplasty, what characteristic of irradiated (10 Mrad) and subsequently melted highly cross-linked polyethylene should provide a more wear-resistant construct than traditional gamma- irradiated (2.5-4 Mrad)-in-air polyethylene mated with the same head?

Explanation

DISCUSSION:
Highly cross-linked polyethylene makes material resistant to adhesive wear. Abrasive wear from third bodies does not decrease wear. The fatigue strength of such material is inferior to that of traditional polyethylene, and its resistance to creep is the same, if not lower, than that of traditional polyethylene.

Question 96

An elite gymnast injured her ankle in an awkward dismount 36 hours ago. Examination reveals weakness on single leg step-up. A clinical photograph of the medial ankle is shown in Figure 15. Plain radiographs are normal. To help confirm the diagnosis, the next step in evaluation should consist of

Explanation

DISCUSSION: Ecchymosis on the medial side of the ankle is distributed in the posterior tibialis tendon sheath location, posterior to the medial malleolus, and extending inferiorly to the tendon’s attachment on the navicular. MRI is the imaging study of choice to determine the extent of tendon damage. MRI will also help assess the deltoid ligament. Bone scans and CT are helpful in identifying osteochondral fractures and occult fractures; however, these studies are not indicated for this patient. Peroneal tendons are located lateral on the ankle. Arthroscopy of the ankle joint would not be helpful in assessing the posterior tibial tendons.
REFERENCES: Lutter LD, Mizel MS, Pfeffer GB (eds): Orthopaedic Knowledge Update: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 307-317.
Rosenberg ZS, Cheung Y, Jahss MH, Noto AM, Norman A, Leeds NE: Rupture of the posterior tibial tendon: CT and MR imaging with surgical correlation. Radiology 1988;169:229-235.

Question 97

Figure 16 shows the clinical photograph of a 3-month-old infant with a foot deformity that has been nonprogressive since birth. Examination reveals that the deformity corrects actively and with passive manipulation. There is no associated equinus. Management should consist of

Explanation

DISCUSSION: The patient has bilateral metatarsus adductus deformities. In a long-term follow-up study by Farsetti and associates, deformities that were passively correctable spontaneously resolved and no treatment was required. More rigid deformities were successfully treated with serial manipulation, with good results in 90%. There were no poor results. Therefore, observation is the management of choice for passively correctable deformities. In feet that are more rigid, serial manipulation and casting is the management of choice.
REFERENCE: Farsetti P, Weinstein SL, Ponseti IV: The long-term functional and radiographic outcomes of untreated and non-operatively treated metatarsus adductus. J Bone Joint Surg Am 1994;76:257-265.

Question 98

A right-handed, 53 year old man reports pain in the left shoulder following a fall on an abducted externally rotated shoulder 3 months ago. Examination reveals pain on elevation and tenderness localized to the anterior aspect of the shoulder. Results of the lift-off test are inconclusive due to limited internal rotation. Figure 2 shows the T1-weighted axial image from an MRI-arthrogram. Treatment should include

Explanation

Subscapularis repair-Traumatic rupture of the tendon of the subscapularis muscle is caused by forceful hyperextension or external rotation of the adducted arm. A simple clinical maneuver called the "lift-off test", reliably diagnosed or excluded clinically relevant rupture of the subscapularis tendon.

Question 99

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Explanation

EXPLANATION:
Reduction, either open or closed, with internal fixation (pinning) is the recommended treatment for the majority of these injuries. Closed reduction with pinning is most often performed for acute injuries. Open reduction with pinning is performed for those injuries that cannot be reduced by closed means or those with a delayed presentation. Four cases of successful closed reduction and splinting, all performed upon presentation in the emergency department, have been described by Storken and associates, but the authors note that their review of three prior reports uncovered cases of secondary dislocation, which required surgical stabilization. One of the dislocations occurred 4 months after the reduction. They assert that an indication for primary ORIF is a CMC dislocation associated with major fractures. Primary arthrodesis can be considered in cases with severe intra-articular comminution, but this procedure substantially limits the ability of the hand to increase and decrease the transverse metacarpal arch, which is an important functional movement. It can also lead to osteoarthritis of the triquetrohamate joint. Suspension arthroplasty has been described for old fracture-dislocations of the fifth CMC joint, using a partial slip of the extensor carpi ulnaris.

Question 100

A 32-year-old has diffuse pain, weakness, and limited overhead motion in the shoulder as a result of falling on his outstretched arm 2 months ago. Examination reveals medial scapular winging, and an electromyogram shows denervation of the long thoracic nerve. Management should consist of

Explanation

Most cases of isolated serratus anterior palsy resolve spontaneously, usually within 6 to 9 months after traumatic injury and within 2 years after an infectious cause. Pectoralis major-fascia lata graft is an effective treatment for persistent winging.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

multiple osteotomies and femoral rodding.
pharmocologic doses of vitamin D and phosphate.
biopsy, followed by appropriate chemotherapy.
pamidronate therapy.
radiation therapy and a bone marrow transplant.

Correct Answer: multiple osteotomies and femoral rodding.

Explanation:

Question 2:

Which factor has the most negative influence on the success of knee osteochondral allograft transplantation?

Options:

Mechanical axis malalignment
Blood-type matching of the host and donor
Sex of the donor
Failed previous cartilage procedure

Correct Answer: Mechanical axis malalignment

Explanation:

Question 3:

Which of the following factors has been shown to be the strongest predictor of screw cutout of a dynamic compression hip screw used for an intertrochanteric femur fracture?

Options:

Age of the patient
Intrinsic stability of the fracture
Tip-apex distance
Quality of reduction
Angle of the sideplate

Correct Answer: Age of the patient

Explanation:

Question 4:

Deep venous thromboses are primarily composed of red blood cells and fibrin. What is fibrin?

Options:

Platelet cytoskeletons
Fragmented collagen
A type of thromboplastin
A product of the coagulation cascade
A product of the fibrinolytic system

Correct Answer: A product of the coagulation cascade

Explanation:

Question 5:

Options:

Increased wettability
Increased hardness
Increased fracture toughness
Decreased surface roughness
Lower coefficient of friction

Correct Answer: Increased fracture toughness

Explanation:

DISCUSSION: Alternative bearing surfaces in THA have received much attention in recent years as more and more hip arthroplasties are being performed on younger patients with hip arthritis. The two most popular nonmetal-on-polyethylene bearing surfaces are metal-on-metal and ceramic-on-ceramic. There are arguments supporting the use of either, but ceramic bearings have been shown to have a theoretic increased risk of fracture compared with cobalt-chromium. This has been shown to be clinically relevant with zirconium ceramics. Newer alumina ceramics are being produced with lower porosity and grain size and with higher density and purity, resulting in lower fracture risk but still greater than that of cobalt-chromium.
REFERENCES: Heisel C, Silva M, Schmalzried TP: Bearing surface options for total hip replacement in young patients. Instr Course Lect 2004;53:49-65.
D’Antonio J, Capello W, Manley M, et al: New experience with alumina-on-alumina ceramic bearings for total hip arthroplasty. J Arthroplasty 2002;17:390-397.

Question 6:

Options:

Advanced degenerative disk disease with facet arthrosis at L5-S1
Decreased T2 signal in the L5-S1 disk with normal facet joints
Previous laminectomy at L5-S1
Fixed tilt of L5 with severe unilateral facet arthrosis
Spondylolysis bilaterally at L5

Correct Answer: Decreased T2 signal in the L5-S1 disk with normal facet joints

Explanation:

Question 7:

Options:

MRI with metal artifact reduction sequence (MARS) only. B. serum cobalt only.
serum cobalt and chromium levels.
serum cobalt and chromium levels and MRI with MARS.

Correct Answer: MRI with metal artifact reduction sequence (MARS) only. B. serum cobalt only.

Explanation:

DISCUSSION:
THA has proven to be durable and reliable for pain relief and improvement of function in patients with end-stage arthritis. Appropriate bearing selection is critical to minimize wear and hip complications. A
metal-on-metal articulation is associated with excellent wear rates in vitro. Because it offers a low wear rate with large femoral heads, it is an attractive bearing choice for THA. However, local soft-tissue reactions, pseudotumors, and potential systemic reactions—including renal failure, cardiomyopathy, carcinogenesis, and potential teratogenesis after the possible transfer of metal ions across the placental barrier—make metal-on-metal bearings less desirable and relatively contraindicated for younger women of child-bearing age.The work-up of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including the erythrocyte sedimentation rate, C-reactive protein (CRP) level, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging, including MRI with MARS, should be performed to evaluate for the presence of fluid collections, pseudotumors, and abductor mechanism destruction. Infection can coexist with metal-on-metal reactions, so when indicated (if the CRP level is elevated), a hip arthrocentesis should be obtained. However, in this setting, a manual cell count and differential should be obtained because an automated cell counter may provide falsely elevated cell counts. The results of revision surgery for a failed metal-on-metal hip prosthesis can be variable. The amount of local tissue destruction and the integrity of the hip abductor mechanism can greatly influence outcomes. Instability is the most common complication following a revision of failed metal-on-metal hip replacements.

Question 8:

- Which of the following radiographic findings would be characteristic of the knee joints of a patient with neuropathic osteoarthropathy of the knee?

Options:

Fragmentation and subluxation of the normal joint articulation
Varus deformity with medial subchondral sclerosis
Preferential narrowing of the medial tibiofemoral compartment
Narrowing of the medial, lateral, and patellofemoral compartments
Bone proliferation at the patellar tendon and ligament insertion sites

Correct Answer: Fragmentation and subluxation of the normal joint articulation

Explanation:

Question 9:

Which of the following methods best aids in diagnosis of an interdigital neuroma?

Options:

Ultrasound
MRI
Web space injection
Electromyography and nerve conduction velocity studies
History and physical examination

Correct Answer: History and physical examination

Explanation:

Question 10:

Options:

Semimembranosis tendonitis
Patellar tendonitis
Iliotibial band friction syndrome
Quadriceps tendonitis

Correct Answer: Patellar tendonitis

Explanation:

Question 11:

Which of the following is a recognized consequence of hip fusion?

Options:

Low back pain
Contralateral knee laxity
Difficulty delivering children
Meralgia paresthetica
Contralateral abductor weakness

Correct Answer: Low back pain

Explanation:

Question 12:

Options:

Patellofemoral syndrome
Bipartite patella
Stress fracture of the distal femur
Patella alta
Patella baja

Correct Answer: Patellofemoral syndrome

Explanation:

Question 13:

Overgrowth of a limb in a patient with neurofibromatosis type 1 (NF1) is most likely associated with the presence of

Options:

dural ectasia.
Lisch nodules.
juvenile xanthogranuloma.
malignant peripheral nerve sheath tumor.
plexiform neurofibroma.

Correct Answer: plexiform neurofibroma.

Explanation:

Question 14:

In a patient who has undergone fusion with instrumentation from T4 to the sacrum for adult scoliosis, at which site is a pseudarthrosis most likely to be discovered?

Options:

T4-T5
T7-T8
L2-L3
L4-L5
L5-S1

Correct Answer: L5-S1

Explanation:

DISCUSSION: Although pseudarthrosis can be found anywhere within the spine that has been fused using long multisegmental fixation to the sacrum, it most commonly occurs at the lumbosacral junction. The thoracolumbar junction is another common site of potential pseudarthrosis. In this location, the anatomy changes from lumbar transverse processes to thoracic through the transition zone, and overlying instrumentation often makes it difficult to obtain enough sound bone on decorticated bone to achieve a successful fusion.
REFERENCES: Saer EH III, Winter RB, Lonstein JE: Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis: An improved method. Spine 1990;15;650-653.
Kostuik JP, Hall BB: Spinal fusions to the sacrum in adults with scoliosis. Spine
1983;8:489-500.
Balderston RA, Winter RB, Moe JH, et al: Fusion to the sacrum for nonparalytic scoliosis in the adult. Spine 1986;11:824-829.

Question 15:

Options:

Femoral attachment of the medial collateral ligament
Tibial attachment of the medial collateral ligament
Hypertrophic zone of the growth plate
Proliferative zone of the growth plate

Correct Answer: Hypertrophic zone of the growth plate

Explanation:

Question 16:

Options:

disruption of the sympathetic nerves during anterior lumbar exposure.
traction on the parasympathetic nerve at the L4-5 level.
not related to the surgical dissection.
injury to the pudendal nerves in the anterior sacral region during dissection at the L5-S1 level.
sexual dysfunction secondary to retrograde ejaculation.

Correct Answer: not related to the surgical dissection.

Explanation:

Question 17:

Options:

Closed head injury
Facial fractures
Splenic rupture
Pelvic ring injuries
Flail chest

Correct Answer: Closed head injury

Explanation:

Question 18:

Options:

MR imaging with contrast
MR imaging without contrast
CT scan along the scaphoid axis
Axial-cut CT scans with reformats

Correct Answer: CT scan along the scaphoid axis

Explanation:

EXPLANATION:
Scaphoid nonunions are difficult to diagnose on plain radiographs, which offer poor reliability when attempting to determine if there is bridging trabeculae crossing the fractures site. CT scans are more useful for diagnosing scaphoid nonunion. When scanned using conventional axial cuts, the slices mayskip through the fracture nonunion site, thereby missing the defect, even with reformats. MR imaging is useful in diagnosing acute scaphoid fractures and has a high sensitivity and diagnostic value for excluding
scaphoid fractures as well. Contrast does not enhance the utility of MR imaging in fracture diagnosis.

Question 19:

What is the most common malignant tumor of the foot?

Options:

Chondrosarcoma
Synovial sarcoma
Osteosarcoma
Clear cell sarcoma
Melanoma

Correct Answer: Melanoma

Explanation:

DISCUSSION: Whereas chondrosarcoma is the most frequently occurring malignant bone tumor of the foot and synovial sarcoma is the most common soft-tissue foot malignancy, the most common malignant tumor overall is melanoma. It constitutes approximately 25% of lesions found on the lower extremity. Furthermore, 31% of all melanomas arise in the foot.
REFERENCES: Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 11-26.
Bos GD, Ester RJ, Woll TS: Foot tumors: Diagnosis and treatment. J Am Acad Orthop Surg 2002;10:259-270.

Question 20:

A 22-month-old girl has cerebral palsy. Which of the following findings is a good prognostic indicator of the child’s ability to walk in the future?

Options:

Asymmetric tonic neck reflex
Moro reflex
Extensor thrust
Positive parachute reaction
Absent foot placement

Correct Answer: Positive parachute reaction

Explanation:

DISCUSSION: For the parachute test, the examiner holds the child prone and then lowers the child rapidly toward the floor. The parachute reaction is normal or positive if the child reaches toward the floor. The Moro or startle reflex should not be present beyond age 6 months. Asymmetric tonic neck reflex, extensor thrust, and absent foot placement are abnormal findings at any age.
REFERENCES: Bleck EE: Orthopaedic Management in Cerebral Palsy. Lavenham, Suffolk, The Lavenham Press, 1987, pp 121-139.
Tachdjian MO: The neuromuscular system: Cerebral palsy, in Wickland EH Jr (ed): Pediatric Orthopaedics, ed 2. Philadelphia, PA, WB Saunders, 1990, vol 2, p 1621.

Question 21:

A patient who underwent intramedullary nailing of a femoral shaft fracture 2 weeks ago now reports groin pain. What is the next most appropriate step in management?

Options:

Obtain a radiograph of the hip
Obtain radiographs of the lumbar spine
Obtain an MRI scan of the lumbar spine
Review the radiographic report from the time of injury
Reassure the patient that the pain will improve and order physical therapy

Correct Answer: Obtain a radiograph of the hip

Explanation:

Question 22:

Options:

Adhesive capsulitis
Calcific tendinitis
Anterior shoulder dislocation
Posterior shoulder dislocation
Glenohumeral osteoarthritis

Correct Answer: Posterior shoulder dislocation

Explanation:

DISCUSSION: The patient has a posterior shoulder dislocation. The AP radiograph shows overlapping of the humeral head on the glenoid. The scapular Y view shows his humeral articular surface posterior to the glenoid. The posterior shoulder dislocation is frequently missed because the patient is comfortable in the "sling" position with the arm adducted and internally rotated across the abdomen. The marked restriction in external rotation on examination raises the suspicion of a posterior dislocation, adhesive capsulitis, or glenohumeral osteoarthritis. The posterior dislocation is diagnosed based on the radiographic findings. An axillary view or CT is recommended to better evaluate the dislocation.
REFERENCES: Robinson CM, Aderinto J: Posterior shoulder dislocations and
fracture-dislocations. J Bone Joint Surg Am 2005;87:639-650.
Cicak N: Posterior dislocation of the shoulder. J Bone Joint Surg Br 2004;86:324-332.

Question 23:

repair of the rotator cuff

Options:

closed reduction and immobilization
open reduction and immobilization
open reduction and early passive motion

Correct Answer: closed reduction and immobilization

Explanation:

Question 24:

- Which of the following conditions associated with a closed fracture of the clavicle indicates the need for open reduction and internal fixation?

Options:

Injury to the subclavian artery
Injury to the brachial plexus
Segmental fracture
100% displacement
Associated displaced surgical neck fracture of the humerus

Correct Answer: Injury to the subclavian artery

Explanation:

Question 25:

Options:

medial sliding calcaneal osteotomy with flexor digitorum longus (FDL) transfer.
isolated subtalar arthrodesis.
isolated talonavicular arthrodesis.
triple arthrodesis.
subtalar arthroereisis.

Correct Answer: triple arthrodesis.

Explanation:

Question 26:

Options:

Sural nerve injury
Tethering of the flexor hallucis longus by fracture fragments
Medial plantar nerve neuropathy
Weakness of the tibialis posterior
Unrecognized foot compartment syndrome

Correct Answer: Sural nerve injury

Explanation:

Question 27:

Options:

Pitchers throwing less fastballs and more changeups
Evaluate the pitchers elbows for ulnar collateral ligament acute ruptures.
Increasing the weight training for the deltoid and latissimus dorsi muscles
Focused stretches and therapies that address posterior capsular tightness
Firing the general manager for finding pitchers that "lose their stuff"

Correct Answer: Pitchers throwing less fastballs and more changeups

Explanation:

Question 28:

Options:

observation.
a knee-ankle-foot orthosis.
a medial proximal tibial epiphyseodesis.
a proximal tibial osteotomy.
lateral proximal tibial stapling.

Correct Answer: observation.

Explanation:

Question 29:

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

Options:

Allograft ACL
Bone-patellar tendon-bone with a width of 10 mm
Fascia lata with a width of 15 mm
Central quadriceps tendon with a width of 15 mm
Quadruple semitendinosus and gracilis tendons

Correct Answer: Quadruple semitendinosus and gracilis tendons

Explanation:

Question 30:

- The stability of the longitudinal arch of the foot during standing with equal weight on both feet is due primarily to

Options:

plantar fascia and quadratus plantae tendon.
ligamentous structures connecting the tarsal bones.
shape of the tarsal bones and the intervening joints.
activity of the intrinsic muscles of the foot.
activity of the posterior tibialis and the peroneus longus muscles.

Correct Answer: ligamentous structures connecting the tarsal bones.

Explanation:

Question 31:

Options:

Midsubstance tear of the lateral ulnar collateral ligament
Proximal avulsion of the ulnar collateral ligament
Proximal avulsion of the lateral ulnar collateral ligament
Distal bony avulsion of the ulnar collateral ligament from the sublime tubercle

Correct Answer: Proximal avulsion of the lateral ulnar collateral ligament

Explanation:

Question 32:

Which of the following complications may occur subsequent to resurfacing hip arthroplasty for osteonecrosis of the hip but not after total hip arthroplasty?

Options:

Aseptic loosening of the acetabular component
Fracture of the femoral neck
Fracture of the acetabulum
Infection
Groin pain

Correct Answer: Fracture of the femoral neck

Explanation:

DISCUSSION: Advocates of resurfacing hip arthroplasty cite preservation of the proximal femoral bone stock as the main advantage of this procedure over total hip arthroplasty. Fracture of the retained femoral neck has been reported following resurfacing arthroplasty. The exact etiology of the latter is unknown. Technical errors, such as notching of the femoral neck or possibly disruption of the blood supply to the femoral head during extensive soft-tissue exposure, may result in femoral neck fracture.
REFERENCES: Gabriel JL, Trousdale RT: Stem fracture after hemiresurfacing for femoral head osteonecrosis. J Arthroplasty 2003;18:96-99.
Amstutz HC, Campbell PA, Le Duff MJ: Fracture of the neck of the femur after surface arthroplasty of the hip. J Bone Joint Surg Am 2004;86:1874-1877.

Question 33:

Options:

10% decrease in amplitude, 50% decrease in latency.
10% decrease in amplitude, 50% increase in latency.
0% loss of amplitude, transient increase in latency.
50% decrease in amplitude, 10% increase in latency.
50% decrease in amplitude, 10% decrease in latency.

Correct Answer: 50% decrease in amplitude, 10% increase in latency.

Explanation:

Question 34:

A 35-year-old woman began to train for a half marathon. After 8 weeks of increasing her mileage, what changes can you expect in her Achilles tendon?

Options:

Net decrease of type I collagen
Net increase of type I collagen
Increased diameter of collagen fibrils
Increased cross-sectional area of the tendon

Correct Answer: Net increase of type I collagen

Explanation:

Question 35:

Figure 29 is the radiograph of a 30-year-old man who sustained an isolated tibial shaft fracture. What is the most common deformity with nonsurgical management?

Options:

Varus
Malrotation
Valgus
Valgus and procurvatum
Valgus and recurvatum

Correct Answer: Varus

Explanation:

Question 36:

A patient notes pain under the first metatarsophalangeal joint following a soccer injury. The MRI scans shown in Figures 27a and 27b reveal what pathologic finding?

Options:

Sesamoid fracture
Phalangeal fracture
Osteochondral lesion
Disruption of the plantar plate
Rupture of the flexor hallucis tendon

Correct Answer: Disruption of the plantar plate

Explanation:

Question 37:

The Lisfranc ligament connects the base of the

Options:

first metatarsal and the medial cuneiform.
first metatarsal and the base of the second metatarsal.
first metatarsal and the middle cuneiform.
second metatarsal and the medial cuneiform.
second metatarsal and the middle cuneiform.

Correct Answer: second metatarsal and the medial cuneiform.

Explanation:

Question 38:

Options:

Silastic arthroplasty
Cheilectomy and soft-tissue interposition arthroplasty
Moberg phalangeal dorsiflexion osteotomy
Bone graft interposition arthrodesis
Waterman first metatarsal dorsal osteotomy

Correct Answer: Bone graft interposition arthrodesis

Explanation:

Question 39:

The arrow in Figure 11 points toward a finding consistent with which of the following?

Options:

Metastatic disease
Hemangioma
Flexion-compression fracture
Infection
Diastomatomyelia

Correct Answer: Metastatic disease

Explanation:

DISCUSSION: The finding of a unilateral absent pedicle is often referred to as a winking owl sign and is a manifestation of pedicle destruction from metastatic disease. As the vertebral body is destroyed from the neoplastic process, it extends into the pedicle and destroys the cortical rim that normally creates the oval ring of the pedicle on an AP image.
REFERENCES: McLain R, Weinstein J (eds): Rothman-Simeone: The Spine, ed 4. Philadelphia, PA, WB Saunders, 1999, p 1173.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 674.

Question 40:

Options:

Range of motion
Infraspinatus strength
Activity level
Quality of the subscapularis

Correct Answer: Quality of the subscapularis

Explanation:

Question 41:

Options:

Cast immobilization and no weight bearing for 4 to 8 weeks
Immobilization in a walking cast for 4 to 8 weeks
Hard-soled shoe for 4 to 8 weeks
Sesamoid bone grafting
Medial sesamoidectomy

Correct Answer: Medial sesamoidectomy

Explanation:

Question 42:

Options:

Torn posterolateral corner
Torn posterior cruciate ligament (PCL) and posterolateral corner
Torn PCL
Rupture of the quadriceps tendon
Rupture of the lateral collateral ligament

Correct Answer: Torn posterolateral corner

Explanation:

Question 43:

Options:

Formality
Empathy
Yes-no questions
Taking copious notes
Sitting leaning back in a chair

Correct Answer: Empathy

Explanation:

Question 44:

Options:

Contact area and contact pressure both decrease.
Contact area and contact pressure both increase.
Contact area and contact pressure both remain the same.
Contact area increases and contact pressure decreases.
Contact area decreases and contact pressure increases.

Correct Answer: Contact area increases and contact pressure decreases.

Explanation:

Question 45:

Options:

a long leg cast.
a reamed nail.
an unreamed nail.
an external fixator.
plates and screws.

Correct Answer: an external fixator.

Explanation:

Question 46:

Options:

immediate internal fixation of the right femoral neck stress fracture.
non-weight-bearing crutch ambulation until symptoms resolve, followed by a gradual resumption of activities.
ultrasound therapy to promote fracture healing.
a metabolic work-up.
a bone scan to look for other stress fractures.

Correct Answer: non-weight-bearing crutch ambulation until symptoms resolve, followed by a gradual resumption of activities.

Explanation:

Question 47:

Options:

Rim width
Rim length
Time from injury to repair
Use of a fibrin clot
Whether the tear occurred in the medial versus lateral meniscus

Correct Answer: Rim width

Explanation:

Question 48:

Options:

spinal accessory nerve, causing shoulder elevation with the scapula translated and the inferior angle rotated medially.
spinal accessory nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.
long thoracic nerve, causing shoulder elevation with the scapula translated medially and the inferior angle rotated medially.
long thoracic nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.
thoracodorsal nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.

Correct Answer: spinal accessory nerve, causing shoulder depression with the scapula translated laterally and the inferior angle rotated laterally.

Explanation:

Question 49:

5 mm of change in the atlanto-dens interval (ADI) between flexion and extension views

Options:

Posterior atlanto-dens interval (PADI) <14 mm
Progressive myelopathy
ADI > 10 mm with no change on flexion/extension views

Correct Answer: Posterior atlanto-dens interval (PADI) <14 mm

Explanation:

Question 50:

Options:

hemivertebra excision.
anterior and posterior spinal fusion with instrumentation from T4 to L4.
convex anterior hemiepiphyseodesis.
convex posterior hemiarthrodesis.
an orthosis.

Correct Answer: hemivertebra excision.

Explanation:

Question 51:

An ulnar nerve palsy at the level of the wrist is typically associated with deficits in the palmaris brevis, the hypothenar muscles, and what other groups of muscles?

Options:

Volar interossei, adductor pollicis, and the deep head of the flexor pollicis brevis
Dorsal interossei, adductor pollicis, and the deep head of the flexor pollicis brevis
Dorsal interossei, adductor pollicis, and both heads of the flexor pollicis brevis
All of the interossei and the abductor pollicis brevis
All of the interossei, adductor pollicis, and the deep head of the flexor pollicis brevis

Correct Answer: All of the interossei, adductor pollicis, and the deep head of the flexor pollicis brevis

Explanation:

DISCUSSION: The intrinsic muscles innervated by the ulnar nerve include the palmaris brevis, hypothenar muscles, all of the interossei, adductor pollicis, and the deep head of the flexor pollicis brevis. The superficial head of the flexor pollicis brevis is innervated by the
median nerve.
REFERENCES: Goldfarb CA, Stern PJ: Low ulnar nerve palsy. JASSH 2003;3:14-26.
Omer G: Ulnar nerve palsy, in Green DP, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4. Philadelphia, PA, Churchill Livingstone, 1999, pp 1526-1541.

Question 52:

Which of the following mechanisms of inhibition has been linked to cigarette smoking and lumbar spinal fusion?

Options:

Diminished revascularization of cancellous bone graft
Increased activity of osteoblasts
Increased activity of osteocytes
Antibody-induced necrosis
Inhibition of prostaglandins

Correct Answer: Diminished revascularization of cancellous bone graft

Explanation:

DISCUSSION: Cigarette smoking has been directly linked to pseudarthrosis in spinal fusions. The direct mechanism of action is diminished revascularization of cancellous bone graft. Additionally, a smaller area of revascularization is seen in these grafts, as well as an increased area of necrosis. Increased activity of osteoblasts would result in more bone production. Increased activity of osteocytes would not affect the fusion because osteocytes are mature bone cells.
REFERENCE: Daftari TK, Whitesides TE Jr, Heller JG, et al: Nicotine on the revascularization of bone graft: An experimental study in rabbits. Spine 1994;19:904-911.

Question 53:

Options:

Osteosarcoma
Osteochondroma
Ewing’s sarcoma
Chondrosarcoma
Periosteal chondroma

Correct Answer: Osteosarcoma

Explanation:

Question 54:

Options:

Fracture of the posterior glenoid
Triceps insertion avulsion
Calcific tendinitis
Posterior glenoid exostosis
Loose body

Correct Answer: Posterior glenoid exostosis

Explanation:

Question 55:

Options:

Resect more distal femur.
Resect more anterior tibia.
Use a larger femoral component.
Use a smaller polyethylene insert.
Recess the posterior cruciate ligament.

Correct Answer: Recess the posterior cruciate ligament.

Explanation:

Question 56:

Options:

Gentamicin and penicillin
Cefazolin and penicillin
Doxycycline and ceftazidime
Vancomycin and sulfamethoxazole-trimethoprim

Correct Answer: Doxycycline and ceftazidime

Explanation:

Question 57:

40A B Figures 40a and 40b are this patient's intraoperative arthroscopic images. The abnormality seen here illustrates which of the patient's clinical findings?

Options:

Instability on unlevel ground
Ankle pain and swelling
Anterior laxity on lateral radiographs
Osteochondral lesion of the talus on MR imaging

Correct Answer: Ankle pain and swelling

Explanation:

DISCUSSION
Ankle sprains are the most common musculoskeletal injury; however, most of these sprains do not progress to chronic instability. Initial injuries are treated with RICE (rest, ice, compression, elevation), range of motion, weight bearing
as tolerated, and proprioceptive therapy. Lace-up ankle braces are most effective during the subacute period after a sprain. Structured physical therapy focused on proprioception is recommended for 6 weeks. Examination findings for ankle ligament instability are unreliable because of associated subtalar joint motion. Casting is not as effective as functional rehabilitation. Stress radiographs are recommended, but a clear pathologic range of measurements is not defined. Generalized ligament laxity can result in false-positive findings of instability; therefore, contralateral stress radiographs are often necessary for comparison. The difference in anterior drawer measurement between both ankles should not exceed 5mm. Likewise, the difference in talar tilt measurement between both ankles should be 5 or fewer degrees. Patients with mechanical symptoms, a joint effusion, or continued pain may have an intra-articular pathology such as a loose body or osteochondral lesion. Ankle instability can exist without ligamentous laxity. Symptoms of chronic instability can result from osteochondral lesions of talus, peroneal tendon pathology, loose bodies, anterior ankle impingement, and fracture nonunions. Although there is not sufficient evidence to recommend arthroscopy prior to all ligament reconstructions, arthroscopy is recommended when other pathology is suspected.
RECOMMENDED READINGS
Colville MR. Surgical treatment of the unstable ankle. J Am Acad Orthop Surg. 1998 Nov-Dec;6(6):368-77. Review. PubMed PMID: 9826420.
View Abstract at PubMed
DiGiovanni CW, Brodsky A. Current concepts: lateral ankle instability. Foot Ankle Int. 2006 Oct;27(10):854-66. Review. PubMed PMID: 17054892.
View Abstract at PubMed
Maffulli N, Ferran NA. Management of acute and chronic ankle instability. J Am Acad Orthop Surg. 2008 Oct;16(10):608-15. Review. PubMed PMID: 18832604.
View Abstract at PubMed

Question 58:

What is the most consistent finding regarding glenohumeral kinematics in patients with symptomatic tears of the rotator cuff?

Options:

No superior translation during abduction
Retention of ball-and-socket kinematics with more than 30 degrees of abduction
Loss of ball-and-socket kinematics with less than 30 degrees of abduction
Superior translation of the humeral head with more than 30 degrees of abduction
Superior translation of the humeral head with external rotation

Correct Answer: Superior translation of the humeral head with more than 30 degrees of abduction

Explanation:

Question 59:

Options:

Giant cell tumor
Nonossifying fibroma
Fibrous dysplasia
Eosinophilic granuloma
Osteofibrous dysplasia

Correct Answer: Osteofibrous dysplasia

Explanation:

DISCUSSION: Osteofibrous dysplasia frequently presents at a very young age, usually less than 10 years. In most patients, it involves the anterior cortex of the tibial shaft and minor anterior bowing of the tibia is frequently seen. The lesion is unpredictable in nature, but local recurrence is very high in patients who undergo surgery before 15 years of age.
REFERENCES: Campanacci M, Laus M: Osteofibrous dysplasia of the tibia and fibula. J Bone Joint Surg Am 1981;63:367-375.
McCaffery M, Letts M, Carpenter B, et al: Osteofibrous dysplasia: A review of the literature and presentation of an additional 3 cases. Am J Orthop 2003;32:479-486.

Question 60:

During C1-C2 transarticular screw fixation, screw misplacement is most likely to result in injury to the

Options:

spinal cord if the screw is angled too medial.
occiput-C1 joint if the screw is angled too cephalad.
occiput-C1 joint if the screw is angled too lateral.
vertebral artery if the screw is angled too cephalad.
vertebral artery if the screw is angled too caudally.

Correct Answer: vertebral artery if the screw is angled too caudally.

Explanation:

Question 61:

What part of the glenoid labrum has the least vascularity?

Options:

Midanterior
Anterior/inferior
Anterior/superior
Posterior/superior
Posterior/inferior

Correct Answer: Anterior/superior

Explanation:

Question 62:

This reporting avoids a ceiling and floor effect, where most of the respondents score either at the top or the bottom of the assessment scale.

Options:

Brodke et al. performed a comparative study of the psychometric properties of
the PROMIS physical function domain, the Oswestry Disability Index (ODI), and the Short Form 36 (SF-36) questionnaire in the spine population. They reported that the PROMIS PF CAT required less time and had less ceiling and floor effects than the ODI and SF-36 questionnaires. Additionally, there was a high correlation between the three evaluation methods. They concluded that the PROMIS system provides better outcomes assessment while taking less time and fewer questions than legacy tests.
Brodke et al. reviewed the literature regarding the use of the PROMIS outcomes measure for several orthopedic conditions. The use of the computerized adaptive testing version allows for a higher level of precision with fewer questions administered and reduced time. In the spine literature, the PROMIS system has shown a reduced ceiling and floor effect compared to other legacy tests. They concluded that this system provides a highly reliable and valid means of measuring patient-reported outcomes while reducing respondent and administrative burden.
Incorrect Answers:

Correct Answer: Brodke et al. reviewed the literature regarding the use of the PROMIS outcomes measure for several orthopedic conditions. The use of the computerized adaptive testing version allows for a higher level of precision with fewer questions administered and reduced time. In the spine literature, the PROMIS system has shown a reduced ceiling and floor effect compared to other legacy tests. They concluded that this system provides a highly reliable and valid means of measuring patient-reported outcomes while reducing respondent and administrative burden.

Explanation:

Which of the following statistical tools is used to determine responsiveness?
The only accurate statement is that, at 1 month, patients in group 3 are more likely to live longer than patients in group 1 and 2.
The Kaplan-Meier curve is a statistical method used in survivorship analysis to estimate survival rates at different time points. The horizontal axis depicts the time points and the vertical axis depicts the probability of survival. At a given time point, greater survivorship is demonstrated by higher values on the vertical axis.
Kocher et al. reviewed clinical epidemiology and biostatistics relevant in orthopaedic
surgery. They reported that survivorship data are typically analyzed with use of the Kaplan-Meier method. This analysis is used when the actual date of the end point is known. A survivorship curve can be plotted to illustrate the percentage of patients still alive after the intervention.
Petrie et al. reviewed statistics, terminology and the principles involved in simple data analysis, and outlines areas of medical statistics that have gained
prominence in recent years in orthopaedic papers. The authors provide an insight into some of the more common errors that occur in published orthopaedic journals and which are frequently encountered at the review stage in papers submitted to the Journal of Bone and Joint Surgery.
Figure A depicts a Kaplan-Meier curve for 3 groups of patients undergoing 3 different interventions.
Incorrect Answers:
When evaluating patient-reported outcomes in spine surgery, the Patient- Reported Outcomes Measurement Information System (PROMIS) has been found to have what differences compared to other assessment tools?
Communication failures have been associated with increased treatment costs, increased complications, and delays in patient care.
The leading cause of medical errors, wrong-site surgeries, diagnostic delays and loss to follow-up is attributed to communication errors. Studies have shown that this directly leads to increased complications, increased treatment costs, and delays in patient care. In the surgical setting, the performance of the pre-surgical time-out affords clarification of the treatment plan, confirmation of the procedure and site, and an opportunity for the team to address any concerns.
Weller et al. reviewed barriers to effective teamwork in healthcare delivery. They found that effective communication across all team members, inclusive training, and the creation of democratic teams can reduce treatment delays and minimize complications. They concluded that all team members should have a shared understanding of the situation when involved in patients care.
Lingard et al. performed a prospective study determining the feasibility of a preoperative 10-item checklist discussion including nurses, surgeons, and anesthesiologists. They reported that the discussion usually took place prior to bringing the patient to the OR and took on average 3.5 minuted. Overall, the guided discussion was very well received by participants and provided an opportunity to inform providers of the patient's information to address potential problems. The authors cited that variations in workflow patterns as a potential barrier to widescale implementation of the checklist discussion.
Incorrect answers:
The outcomes of three novel interventions are investigated and the preliminary results are depicted in Figure A. Which of the following statements is most accurate?
Linezolid acts to inhibit protein synthesis by preventing the formation of the initiation complex between the 30S and 50S subunits of the ribosome.
Linezolid is a type of oxazolidinone, a relatively newer class of antibiotics that are active against multidrug-resistant staphylococci, streptococci, and enterococci. Although many antimicrobial agents affect or disrupt protein synthesis in bacteria, linezolid is unique in that it disrupts protein synthesis at its origin rather than later in the cascade. It achieves this by binding to the
50S subunit of the bacterial ribosome, preventing the formation of the initiation complex.
Swaney et al. performed a study to investigate the mechanism of action of linezolid. They found that linezolid inhibits the formation of the initiation complex in bacterial translation systems by preventing the formation of the N- formylmethionyl-tRNA-ribosome-mRNA ternary complex.
Thompson et al. performed a study on the efficacy of various antibiotics in treating periprosthetic joint infections (PJI). They administered oral linezolid with or without oral rifampin, intravenous vancomycin with oral rifampin, intravenous daptomycin or ceftaroline with or without oral rifampin, oral doxycycline, or sham treatment at human- exposure doses for 6 weeks in a mouse model of PJI. They found that oral-only linezolid-rifampin and all intravenous antibiotic-rifampin combinations resulted in no recoverable bacteria and minimized reactive bone changes. Additionally, although oral linezolid was found to be the most effective monotherapy, all oral and intravenous antibiotic monotherapies failed to clear infection or prevent reactive bone changes.
They concluded that the oral-only linezolid-rifampin option might reduce venous access complications and health-care costs.
Illustration A is a diagram depicting the mechanism of action of various antibiotics.
Incorrect Answers:
50S subunit of the bacterial ribosome, preventing protein chain elongation by inhibiting peptidyl transferase activity of the ribosome.
elongation by blocking aminoacyl translocation.
Failure of effective communication in the surgical setting has been associated with what?
Unfractionated heparin works in the coagulation cascade by promoting the ability of antithrombin III to inhibit factors IIa, III, Xa.
Heparin works by binding to and enhancing the ability of antithrombin III to inhibit factors IIa, III, Xa. It is metabolized by the liver. The risks associated with the use of unfractionated heparin include bleeding and heparin induced thrombocytopenia (HIT). The reversal agent is protamine sulfate.
Agnelli et al. reviewed direct thrombin inhibitors for the prevention of VTE after major orthopaedic surgery. They reported widespread use, however, limitations in the use of unfractionated heparin and low-molecular-weight heparins. They highlighted that direct thrombin inhibitors (Ximelagatran) inactivate thrombin without requiring any plasma cofactor, inhibit both free
and fibrin-bound thrombin, and do not appreciably bind to plasma proteins. They concluded that the features of rapid absorption, conversion, bioavailability, low variability, dose-time, food independency, and the predictable anticoagulant activity make direct thrombin inhibitors an attractive antithrombotic agent especially for prolonged out-of hospital prophylaxis.
Kwong et al. reviewed the efficacy and safety of fondaparinux, a selective factor Xa inhibitor and reported its efficacy and safety in 4 phase III clinical trials. They reported fondaparinux usage resulted in an overall 55% decrease in the risk of venous thromboembolism (VTE) relative to the low-molecular- weight heparin enoxaparin without increasing the incidence of clinically relevant bleeding, which was similarly low for both agents. They concluded
that the superior efficacy of fondaparinux relative to enoxaparin is the result of its unique mechanism of action, clinical pharmacology.
McLynn et al. investigated the risk factors and chemoprophylaxis for VTE in elective spine surgery. They reported that independent risk factors for VTE included greater age, male gender, increasing body mass index, dependent functional status, lumbar spine surgery, longer operative time, perioperative blood transfusion, longer length of stay, and other postoperative
complications. The majority of patients received unfractioned heparin and they observed this did not significantly influence the rate of VTE, but was associated with a significant increase in hematoma requiring a return to the operating room. They concluded that there is insufficient evidence to support the routine use of chemoprophylaxis in low-risk patients, and recommended full consideration of risks and benefits after elective spine surgery.
Figure A depicts the coagulation cascade, with the factor circled in red (IIa) being the target of unfractionated heparin, through its effect on antithrombin III.
Incorrect Answers:
Which of the following antibiotics acts to inhibit protein synthesis by preventing the formation of the initiation complex between the 30S and 50S subunits of the ribosome?
Acetaminophen inhibits prostaglandin E2 production through its effect on interleukin-1 beta. It exerts its effects on the central nervous system.
Multimodal pain management has become an increasingly important consideration in total joint arthroplasty recovery, namely in regard to minimizing opioid requirements while optimizing pain control and patient satisfaction. Given the negative side effects and increasing scrutiny on narcotic use, modalities that help to decrease post-operative narcotic requirements have become a major focus and include nonsteroidal anti- inflammatories, selective COX-2 inhibitors, gabapentinoids, local anesthetic blocks, and acetaminophen. Acetaminophen acts directly the central nervous system, providing both pain relief and antipyretic effects. It does so by inhibiting prostaglandin E2 production through the blockade of interleukin-1 beta.
Jinnah et al. performed a comparison of two multimodal pain regimens used for postoperative pain control in total joint arthroplasty patients. They hypothesized that using a multimodal pain protocol focusing on periarticular injections including liposomal bupivacaine would have improved results when compared with a parenteral opioid- based regimen. They found a decrease in length of stay and rate of discharge to skilled nursing facilities with the implementation of a novel multimodal protocol. They concluded that a multimodal approach inclusive of periarticular injection can lead to a reduced
length of stay.
Politi et al. performed a prospective randomized trial comparing the use of intravenous versus oral acetaminophen in total joint arthroplasty. They found that IV acetaminophen did not provide a significant difference in pain relief except within the first 0-4 hours. They concluded that IV acetaminophen does not provide a significant benefit when compared to the oral form, which is also less expensive.
Incorrect Answers:
Which of the following agents results in blood anticoagulation by exerting inhibitory effects on the factor circled in the color red in Figure A?
Based on the stress-strain curve in Figure A, ceramic has the highest modulus of elasticity.
Young's modulus is a measure of the stiffness (ability to resist deformation) of a material in the elastic zone that is calculated by measuring the slope of the stress-strain curve in the elastic zone. A higher modulus of elasticity indicates a stiffer material. Relative values of Young's modulus include: (1) ceramic, (2) alloy, (3) stainless steel, (4) titanium, (5)
cortical bone, (6) matrix polymers, (7) PMMA, (8) polyethylene, (9) cancellous bone, (10) tendon/ligaments, and (11) cartilage.
Lang et al. published a review on the use of ceramics in total hip replacement. They report that properties of ceramic which make it particularly attractive for this application include its hardness, high compression strength, and excellent wettability. However, its low fracture toughness and linear elastic behavior make it prone to breakage under stress.
Figure A is a stress-strain curve, the slope of which is used to determine Young's modulus.
Incorrect Answers:
Which of the following medications work by inhibiting prostaglandin E2 production through interleukin-1 beta?
A power analysis determines the minimum number of patients needed in a study to show a clinically significant difference. It should be performed before starting the study.
Power is the probability of finding a significant association if one truly exists. It is defined as 1 minus the probability of a type 2 error (beta) and is generally set to 80% meaning that we are willing to accept a 20% chance of a type 2 error. A power analysis will determine the minimum number of patients that shows a clinically significant difference. The minimum number of patients should be determined prior to initiating a study. Calculation of power after a study has been completed is controversial and discouraged.
Vavken et al. performed a review on the management of confounding in controlled orthopaedic trials. They report that confounding occurs when the effect of exposure of an outcome is distorted by a confounding factor and will lead to spurious effect estimates in clinical studies. They performed a cross- sectional study of a sample of controlled trials reported in the orthopaedic literature in 2006. They conclude that only 30 studies reported that the had a power analysis performed.
Kocher et al. performed a review of clinical epidemiology and biostatistics as a primer for orthopedic surgeons. They report that a power analysis should be performed prior to initiating the study. This will ensure the study is appropriately powered and decrease the effects of chance. They conclude that when a study determines no significant effect the power of the study should be reported.
Incorrect Answers:
Based on the stress-strain curve in Figure A, which of the following materials has the highest modulus of elasticity?
The World Health Organization (WHO) defines osteopenia as a bone mineral density (BMD) that is between 1 and 2.5 standard deviations below young normal (T-score of - 1 to -2.5).
The WHO defines osteopenia as decreased BMD without fracture risk. Osteopenia is defined as a T-score of 1 to 2.5 standard deviations below young normals (-1 to -2.5), while osteoporosis is defined as a T-score of more than

Question 63:

Options:

a shoulder spica cast with the upper extremity in the salute position.
a sling and swathe for 3 weeks, followed by gradual motion and strengthening.
closed reduction and antegrade intramedullary pinning.
closed reduction and retrograde intramedullary nailing.
open reduction and internal fixation with small plates and screws.

Correct Answer: a sling and swathe for 3 weeks, followed by gradual motion and strengthening.

Explanation:

DISCUSSION: In this age group, bayonet apposition can produce very good results. Healing occurs rapidly, and remodeling usually is complete in less than 1 year. All of the other methods have significant risks of complications and are unnecessary for this fracture.
REFERENCES: Martin RF: Fractures of the proximal humerus and humeral shaft, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994,
pp 144-148.
Sanders JO, Rockwood CA Jr, Curtis RJ: Fractures and dislocation of the humeral shaft and shoulder, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 937-939.

Question 64:

What nerve is most at risk during placement of the anterolateral portal in elbow arthroscopy?

Options:

Median
Ulnar
Radial
Posterior interosseous
Anterior interosseous

Correct Answer: Radial

Explanation:

Question 65:

Options:

an avulsion of the lesser tuberosity.
a midsubstance tear of the capsule.
a tear of the anterior inferior labrum.
a tear of the subscapularis.
a tear of the humeral insertion of the inferior glenohumeral ligament.

Correct Answer: a tear of the humeral insertion of the inferior glenohumeral ligament.

Explanation:

Question 66:

Options:

Trochanteric bursitis
Femoral component loosening
Iliopsoas tendonitis
Acetabular component loosening

Correct Answer: Iliopsoas tendonitis

Explanation:

Question 67:

Options:

Anterior cord syndrome
Central cord syndrome
Brown-Sequard syndrome
Posterior cord syndrome
Spinal shock

Correct Answer: Anterior cord syndrome

Explanation:

Question 68:

Options:

axillary nerve.
musculocutaneous nerve.
median nerve.
radial nerve.

Correct Answer: musculocutaneous nerve.

Explanation:

Question 69:

Options:

Nonossifying fibroma
Fibrous dysplasia
Unicameral bone cyst
Osteogenesis imperfecta
Osteofibrous dysplasia

Correct Answer: Osteofibrous dysplasia

Explanation:

Question 70:

Options:

Triple antibiotic coverage
Transfer to the ICU and a consult with infectious disease
Urgent irrigation and debridement with gentle skin closure
Urgent hyperbaric oxygen treatments and immunoglobulin
Urgent aggressive debridement of skin, subcutaneous fat, and fascia

Correct Answer: Urgent aggressive debridement of skin, subcutaneous fat, and fascia

Explanation:

Question 71:

A 66-year-old man has a high-grade angiosarcoma of the right tibia. A radiograph is shown in Figure 43. Treatment should consist of

Options:

amputation.
wide resection.
radical resection.
radiation therapy.
chemotherapy.

Correct Answer: amputation.

Explanation:

Question 72:

What is the primary reason for including the ilium in the distal fixation of long instrumentation constructs in adult scoliosis?

Options:

Better coronal balance
Better pelvic balance
Reduced fretting and corrosion
Improved curve correction
Improved fusion success

Correct Answer: Improved fusion success

Explanation:

DISCUSSION: Studies have shown that when compared with fixation to the sacrum alone, the success rate of fusion across the lumbosacral junction increases when both the sacrum and ilium are included in the posterolateral construct. Curve correction, coronal balance, and pelvic balance are all attended to within the thoracolumbar spine and are not directly related to the pelvic fixation. Fretting and corrosion are a byproduct of metal-to-metal connections.
REFERENCES: Islam NC, Wood KB, Transfeldt EE, et al: Extension of fusions to the pelvis in idiopathic scoliosis. Spine 2001;26:166-173.
Emami A, Deviren V, Berven S, et al: Outcome and complications of long fusions to the sacrum in adult spine deformity: Luque-Galveston, combined iliac and sacral screws, and sacral fixation. Spine 2002;27:776-786.

Question 73:

What tendon has an intra-articular (instrasynovial) location in the knee joint?

Options:

Patellar
Popliteal
Semitendinosus
Semimembranosus
Biceps femoris

Correct Answer: Popliteal

Explanation:

Question 74:

Options:

Failure of patellar polyethylene
Loosening of the femoral component
Loosening of the tibial component
Loosening of the patellar component
Wear-induced osteolysis

Correct Answer: Failure of patellar polyethylene

Explanation:

Question 75:

.What is the most appropriate treatment if instability is present at the time of evaluation?

Options:

TEA
Distal humeral replacement arthroplasty
Arthroscopic release with debridement
Soft-tissue interposition arthroplasty DISCUSSION.. The radiographs reveal ulnohumeral arthrosis with relative sparing of the radiocapitellar articulation secondary to underlying osteoarthritis. Arthrosis of the elbow joint in this young and active patient presents a treatment dilemma for the surgeon. Interposition arthroplasty allows for improved function with pain relief and no weight-lifting restrictions, as required with TEA. This option is an intermediate procedure that preserves bone stock and allows for conversion to a TEA if necessary. Conventional TEA would provide pain relief with improved range of motion, but activity limitation and lifetime weight restrictions make this an undesirable option. Arthroscopic debridement is not an option, considering the previous failure from this modality. Contraindications for soft-tissue interposition arthroplasty include elbow instability, active infection, and pain without motion loss. Common complications associated with this procedure include instability, infection, ulnar neuropathy, bone resorption, and heterotopic bone formation.

Correct Answer: Soft-tissue interposition arthroplasty DISCUSSION.. The radiographs reveal ulnohumeral arthrosis with relative sparing of the radiocapitellar articulation secondary to underlying osteoarthritis. Arthrosis of the elbow joint in this young and active patient presents a treatment dilemma for the surgeon. Interposition arthroplasty allows for improved function with pain relief and no weight-lifting restrictions, as required with TEA. This option is an intermediate procedure that preserves bone stock and allows for conversion to a TEA if necessary. Conventional TEA would provide pain relief with improved range of motion, but activity limitation and lifetime weight restrictions make this an undesirable option. Arthroscopic debridement is not an option, considering the previous failure from this modality. Contraindications for soft-tissue interposition arthroplasty include elbow instability, active infection, and pain without motion loss. Common complications associated with this procedure include instability, infection, ulnar neuropathy, bone resorption, and heterotopic bone formation.

Question 76:

Which of the following findings helps to distinguish between stress fractures of the tibia and shin splints?

Options:

With shin splints, a bone scan shows the posterior tibial cortex in a diffuse, longitudinal orientation.
With tibial shin splints, the bone scan is more intense.
A more diffuse area of tenderness is seen in tibial stress fractures.
A three-phase bone scan is positive in all phases with shin splints, but only positive in delayed

Correct Answer: With shin splints, a bone scan shows the posterior tibial cortex in a diffuse, longitudinal orientation.

Explanation:

Question 77:

Options:

Removal of hardware with tendon transfer
Repair of the extensor pollicis longus (EPL) tendon primarily
Thumb interphalangeal (IP) arthrodesis
Nonsurgical treatment with cast placement keeping the thumb in a fully extended position for 4 weeks

Correct Answer: Removal of hardware with tendon transfer

Explanation:

Question 78:

Options:

Distal radial ulnar joint (DRUJ) ligament reconstruction
Ulnar head implant arthroplasty
Radial shaft osteotomy
One-bone forearm procedure

Correct Answer: Radial shaft osteotomy

Explanation:

Question 79:

98 degrees (range, 0 degrees to 9 degrees). In knees with varus joint lines

Options:

>4 degrees (normal = neutral), the posterior condylar angle was more internally rotated relative to the transepicondylar axis. Therefore, to prevent internal malalignment using standard components, the femoral component should be more externally rotated relative to the posterior condylar axis in this scenario.
Incorrect Answers:

Correct Answer: >4 degrees (normal = neutral), the posterior condylar angle was more internally rotated relative to the transepicondylar axis. Therefore, to prevent internal malalignment using standard components, the femoral component should be more externally rotated relative to the posterior condylar axis in this scenario.

Question 80:

Which of the following mechanisms of inhibition has been linked to cigarette smoking and lumbar spinal fusion?

Options:

Diminished revascularization of cancellous bone graft
Increased activity of osteoblasts
Increased activity of osteocytes
Antibody-induced necrosis
Inhibition of prostaglandins

Correct Answer: Diminished revascularization of cancellous bone graft

Explanation:

DISCUSSION: Cigarette smoking has been directly linked to pseudarthrosis in spinal fusions. The direct mechanism of action is diminished revascularization of cancellous bone graft. Additionally, a smaller area of revascularization is seen in these grafts, as well as an increased area of necrosis. Increased activity of osteoblasts would result in more bone production. Increased activity of osteocytes would not affect the fusion because osteocytes are mature bone cells.
REFERENCE: Daftari TK, Whitesides TE Jr, Heller JG, et al: Nicotine on the revascularization of bone graft: An experimental study in rabbits. Spine 1994;19:904-911.

Question 81:

- A 40-year old man has limited, painful motion in dorsiflexion at the metatarsophalangeal (MTP) joint of the right great toe, despite nonsurgical treatment. Radiographs show dorsal and medial osteophytes and minimal narrowing of the articular space. Treatment should consist of

Options:

Arthrodesis of the MTP joint
A Silastic implant of the MTP joint
Resection arthroplasty of the MTP joint
Cheilctomy of the MTP joint
Osteotomy of the base of the proximal phalanx

Correct Answer: Cheilctomy of the MTP joint

Explanation:

Question 82:

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

Options:

an Ogden-type plate with screws and cerclage bands or cables.
allograft bone plates fixed with cerclage cables and wires.
skeletal traction for 8 weeks.
revision of the femoral stem.
resection arthroplasty.

Correct Answer: revision of the femoral stem.

Explanation:

Question 83:

Which of the following represents a contraindication for interspinous process decompression for the treatment of lumbar spinal stenosis? Review Topic

Options:

Grade I degenerative spondylolisthesis
Inability to walk at least 100 feet
Cauda equina syndrome
Fixed sensory deficit
Intermittent foot drop

Correct Answer: Cauda equina syndrome

Explanation:

Question 84:

A 14-year-old girl has had progressive heel pain for the past several months. Based on the radiograph, MRI scan, and biopsy specimens shown in Figures 37a through 37d, treatment should include

Options:

observation.
wide resection.
radiation therapy.
extended curettage.
chemotherapy.

Correct Answer: extended curettage.

Explanation:

DISCUSSION: An aneurysmal bone cyst is a benign, locally destructive lesion of bone. Most are seen in patients in the second decade of life. The clinical presentation varies, but most patients have pain, tenderness, swelling, and/or pathologic fracture. Radiographs show a radiolucent lesion sometimes with expansile remodeling of the cortex. MRI best detects the commonly seen fluid-fluid levels associated with this lesion. Histologic findings include
blood-filled spaces with bland fibrous connective tissue septa. The stroma has histiocytes, fibroblasts, scattered giant cells, hemosiderin, and occasional inflammatory cells. Treatment of these lesions consists of extended curettage, plus or minus the use of adjuvants (liquid nitrogen, phenol, argon beam coagulation), and finally filling the bone void (allograft or other bone substitute).
REFERENCES: Gibbs CP Jr, Hefele MC, Peabody TD, et al: Aneurysmal bone cyst of the extremities: Factors related to local recurrence after curettage with a high-speed burr. J Bone Joint Surg Am 1999;81:1671-1678.
Ramirez AR, Stanton RP: Aneurysmal bone cyst in 29 children. J Pediatr Orthop 2002;22:533-539.

Question 85:

Options:

in situ subtalar fusion.
tibiotalocalcaneal arthrodesis using an intramedullary rod.
ankle arthroscopy with debridement of osteophytes.
subtalar distraction bone block arthrodesis.
lateral wall ostectomy of the calcaneus.

Correct Answer: subtalar distraction bone block arthrodesis.

Explanation:

Question 86:

As reflected by the SF-36 scores, patients with which of the following conditions demonstrate the most disability in physical function?

Options:

AIDS
Polytrauma
Pelvic fracture
Pilon fracture
Acute myocardial infarction (AMI)

Correct Answer: Pilon fracture

Explanation:

DISCUSSION: Pollak and associates found that the average SF-36 score for patients who sustained a pilon fracture was significantly lower than patients with diabetes mellitus, AIDS, hypertension, asthma, migraines, pelvic fracture, polytrauma, and AMI. Moreover, patients having undergone pilon fixation scored lower on all but three of the SF-36 scales (vitality, mental health, and emotional health).
REFERENCE: Pollak AN, McCarthy ML, Bess RS, et al: Outcomes after treatment of high-energy tibial plafond fractures. J Bone Joint Surg Am 2003;85:1893-1900.

Question 87:

Options:

insert a standard humeral prosthesis with cerclage wires at the fracture site and autologous cancellous bone graft.
insert a standard humeral component and apply a humeral orthosis postoperatively.
cement a long-stemmed humeral component to bypass the fracture site and supplement with cerclage wires.
remove all instrumentation, perform an open reduction and internal fixation of the fracture, and delay completion of replacement surgery until the fracture has healed.
discontinue the procedure and return for completion of total shoulder replacement when the fracture has healed.

Correct Answer: cement a long-stemmed humeral component to bypass the fracture site and supplement with cerclage wires.

Explanation:

Question 88:

Options:

Anterior only
Anterior and medial
Anterior and lateral
Posterior and medial
Posterior and lateral

Correct Answer: Posterior and lateral

Explanation:

Question 89:

Figure 62a and Figure 62b

Options:

Nerve palsy
Skin necrosis
Flexion instability
Patellar instability
Anterior knee pain
Malalignment

Correct Answer: Nerve palsy

Explanation:

Question 90:

The best candidate for a reverse total shoulder arthroplasty is a patient with rotator cuff tear arthropathy with Review Topic

Options:

anterior superior escape.
rheumatoid arthritis.
an acromial stress fracture.
a centered head and an external rotation lag sign of 50 degrees.
active forward elevation of 130 degrees.

Correct Answer: anterior superior escape.

Explanation:

Question 91:

Options:

biceps subluxation.
glenoid rim fracture.
subscapularis detachment.
loose body.
deficient anterior capsule.

Correct Answer: deficient anterior capsule.

Explanation:

Question 92:

Figures 3a and 3b show the MRI scans of a patient with neck pain. What is the most likely diagnosis?

Options:

Neurofibromatosis
Multiple sclerosis
Cervical spondylotic myelopathy
Acute poliomyelitis
Gaucher’s disease

Correct Answer: Neurofibromatosis

Explanation:

Question 93:

Options:

Dislocation of the great toe MTP joint
Rupture of the volar plate
Fracture of the lateral sesamoid
Fracture of the lateral sesamoid and rupture of the plantar plate
Subluxation of the sesamoids

Correct Answer: Fracture of the lateral sesamoid and rupture of the plantar plate

Explanation:

Question 94:

Deep anterior compartment

Options:

Anterior compartment
Compartment syndrome is most commonly missed in the deep posterior compartment. Like the anterior compartment, the deep posterior compartment is enveloped in fascia and is immediately adjacent to the tibia; however, the deep posterior compartment is more difficult to clinically assess secondary to its deep location. Associated findings include pain with passive extension of the toes and plantar foot numbness.
Compartment syndrome involving the superficial posterior compartment, lateral compartment, and anterior compartment is easy to detect because it is readily palpable on examination.
There is no deep anterior compartment in the leg.

Correct Answer: Compartment syndrome is most commonly missed in the deep posterior compartment. Like the anterior compartment, the deep posterior compartment is enveloped in fascia and is immediately adjacent to the tibia; however, the deep posterior compartment is more difficult to clinically assess secondary to its deep location. Associated findings include pain with passive extension of the toes and plantar foot numbness.

Explanation:

How many compartments exist in the foot:

Question 95:

Options:

Resistance to adhesive wear B. Resistance to abrasive wear C. Resistance to fatigue wear
Resistance to creep

Correct Answer: Resistance to creep

Explanation:

Question 96:

Options:

MRI to assess for posterior tibialis tendon damage.
enhanced CT to assess for an osteochondral fracture.
tenography of the peroneal tendons to assess for tendon sheath tearing with subluxation.
a bone scan to assess for occult fracture.
arthroscopy of the ankle to assess for articular cartilage damage.

Correct Answer: MRI to assess for posterior tibialis tendon damage.

Explanation:

Question 97:

Options:

serial casting.
UCBL orthotics.
abductor hallucis lengthening.
observation and parental reassurance.
corrective shoes.

Correct Answer: observation and parental reassurance.

Explanation:

Question 98:

- A right-handed, 53 year old man reports pain in the left shoulder following a fall on an abducted externally rotated shoulder 3 months ago. Examination reveals pain on elevation and tenderness localized to the anterior aspect of the shoulder. Results of the lift-off test are inconclusive due to limited internal rotation. Figure 2 shows the T1-weighted axial image from an MRI-arthrogram. Treatment should include

Options:

Labral repair
acromioplasty
excision of the coracoid process
an arthroscopic Bankart procedure
subscapularis repair

Correct Answer: subscapularis repair

Explanation:

Question 99:

A 44-year-old man sustains the injury shown in Figures 1 through 3. What is the most appropriate treatment?

Options:

Reduction and internal fixation
Closed reduction and splinting alone
Carpometacarpal arthrodesis
Carpometacarpal (CMC) joint suspension arthroplasty

Correct Answer: Reduction and internal fixation

Explanation:

Question 100:

- A 32-year-old has diffuse pain, weakness, and limited overhead motion in the shoulder as a result of falling on his outstretched arm 2 months ago. Examination reveals medial scapular winging, and an electromyogram shows denervation of the long thoracic nerve. Management should consist of

Options:

scapulothoracic fusion
strengthening of the periscapular muscles
pectoralis minor-fascia lata graft transfer to the scapula
pectoralis major-fascia lata graft transfer to the scapula
exploration of the long thoracic nerve, with sural nerve graft

Correct Answer: strengthening of the periscapular muscles

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Master Urinary Tract Stones: 2019 Exam Questions

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