Orthopedic Board Review MCQs: Arthroplasty | Part 119

About This Board Review Set

This is Part 119 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

This set has been strictly audited and contains 100 100% verified, high-yield multiple-choice questions (MCQs) modelled on the exact format of the Orthopaedic In-Training Examination (OITE) and the American Academy of Orthopaedic Surgeons (AAOS) board examinations.

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Pro Tip: Use keyboard shortcuts A–E to select options, F to flag a question for review, and Enter to jump to the next unanswered question.

Topics Covered in Part 119

This module focuses heavily on: Arthroplasty, Elbow, Fracture, Hip, Infection, Knee.

Sample Questions from This Set

Sample Question 1: CLINICAL SITUATIONFigures 1 through 3 are the radiographs of a 25-year-old man who is brought to the emergency department after a motorcycle collision. He is complaining of isolated knee pain. Examination reveals swelling, popliteal ecchymo...

Sample Question 2: Figures 1 and 2 demonstrate the radiographs obtained from a 35-year-old woman with end-stagedebilitating osteoarthritis of the right hip. She is contemplating total hip arthroplasty (THA). She has a history of right hip dysplas...

Sample Question 3: A 12-year-old boy reports limping and chronic knee pain that is now inhibiting his ability to participate in sports. Clinical examination and radiographs of the knee are normal. Additional evaluation should include...

Sample Question 4: In a patient with a major head injury and a femoral shaft fracture, intraoperative hypotension during femoral fixation has been associated with which of the following?...

Sample Question 5: A 25-year old right-hand dominant professional baseball pitcher complains of posteromedial right elbow pain that is worsened by throwing. He also reports occasional paresthesias in his small and ring finger after lengthy bullpen sessions. O...

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Evidence consistently demonstrates that active recall through spaced MCQ practice yields substantially greater long-term retention than passive reading alone (Roediger & Karpicke, 2006). All questions in this specific module have been algorithmically verified for clinical integrity and complete explanations.

Comprehensive 100-Question Exam

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Question 1

CLINICAL SITUATION Figures 1 through 3 are the radiographs of a 25-year-old man who is brought to the emergency department after a motorcycle collision. He is complaining of isolated knee pain. Examination reveals swelling, popliteal ecchymosis, joint line pain, and limited knee joint motion. His pulses and sensation are normal. Initial surgical management should consist of

Explanation

Discussion: Medial plateau fracture dislocations are rare. Failure to recognize this pattern can lead to poor patient outcomes secondary to poor surgical decision making. Pathognomonic findings on the anteroposterior radiograph include an intact lateral column (lateral articular surface still in continuity with tibial shaft), centrolateral articular impaction, shortening, and condylar widening. The medial femoral condyle stays with the fractured medial tibial plateau segment.
Initial management of axially unstable tibial plateau fractures with soft tissue swelling should consist of spanning external fixation and closed manipulative realignment. This allows for soft tissue recovery with the knee joint provisionally stabilized in reduced station. It also provides time for pre-operative planning, which is typically empowered via a CT scan with reconstructions. If the pattern was initially misdiagnosed as a more typically bicondylar tibial plateau fracture, the CT scan will clarify the misconception and allow for better surgical decision making.
Supine positioning is preferred for definitive fixation, but surgical approaches vary. Attempting to stabilize a medial partial articular pattern in the supine position from a lateral utility approach is fraught with difficulties. Lateral locked plating is not designed for this indication. The lateral utility approach allows for visualization of the centrolateral impaction and lateral meniscal peripheral capsular avulsion repair,
but when used alone leads to biomechanically unsound implant placement. The primary plate should be on the medial side of the tibia rather than the intact lateral column.

Question 2

Figures 1 and 2 demonstrate the radiographs obtained from a 35-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. Which bearing surface is contraindicated for this patient?

Explanation

DISCUSSION:
THA has proven durable and reliable for pain relief and improving function for 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. With its capacity to offer 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 with potential 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 workup of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including sedimentation rate, CRP, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging including MARS MRI 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 revision of failed metal-on-metal hip replacements.

Question 3

A 12-year-old boy reports limping and chronic knee pain that is now inhibiting his ability to participate in sports. Clinical examination and radiographs of the knee are normal. Additional evaluation should include

Explanation

DISCUSSION: While all of the answers may be appropriate, radiating pain from hip pathology must be excluded. At this age, a slipped capital femoral epiphysis is likely. Therefore, the hip must be examined.
REFERENCES: Kocher MS, Bishop JA, Weed B, et al: Delay in diagnosis of slipped capital femoral epiphysis. Pediatrics 2004;113:322-325.
Matava MJ, Patton CM, Luhmann S, et al: Knee pain as the initial symptom of slipped capital femoral epiphysis: An analysis of initial presentation and treatment. J Pediatr Orthop 1999;19:455-460.

Question 4

In a patient with a major head injury and a femoral shaft fracture, intraoperative hypotension during femoral fixation has been associated with which of the following?

Explanation

DISCUSSION: Hypoxia and hypotension are associated with lower GCS scores in polytrauma patients with major head injuries, but whether early fracture fixation adversely affect CNS outcomes has been controversial. New studies, however, have found no association between early surgery and decreased discharge GCS scores. The referenced study by Scalea et al reviewed 171 patients with pelvic or lower extremity fractures and head injuries; they showed no difference in CNS outcomes or mortality in patients who underwent early fixation. The second reference by Brundage et al showed improved outcomes (including high GCS scores at time of discharge) in those who had early fixation of femoral shaft fractures in the head-injured patient. The last referenced study by Jaicks et al found a lower discharge GCS in the early fracture fixation group compared with the late group. However, they also found that early fracture fixation was associated with hypoxemia and hypotension, as well as greater fluid administration.

Question 5

A 25-year old right-hand dominant professional baseball pitcher complains of posteromedial right elbow pain that is worsened by throwing. He also reports occasional paresthesias in his small and ring finger after lengthy bullpen sessions. On examination, he is tender along the medial olecranon and complains of pain when extending the elbow >- 20° of extension. He has negative valgus stress, moving valgus stress, and milking maneuver tests. He is stable to varus stress, chair rise, and lateral pivot shift tests. Radiographs reveal a small osteophyte along the posteromedial border of the olecranon. What is the most likely diagnosis?

Explanation

A patient sustains a displaced diaphyseal humerus fracture following a motor vehicle accident. Open reduction internal fixation is indicated due to concomitant lower extremity trauma and is planned through an anterior approach. Which intramuscular interval is exploited during the deep dissection of the mid-humerus in this approach?
A. Lateral head of triceps (radial nerve) and brachialis (musculocutaneous nerve)
B. Lateral head of the triceps (radial nerve) and biceps brachii (musculocutaneous nerve)
C. Lateral brachialis (radial nerve) and medial brachialis (musculocutaneous nerve)
D. Brachialis (musculocutaneous nerve) and coracobrachialis (musculocutaneous nerve)

Question 6

A 78-year-old woman has had activity-limiting cervical pain and occipital headaches for the past 4 years. Management consisting of injections, analgesics, and part-time collar wear has provided temporary relief. Examination reveals that her neck pain seems to be primarily located immediately below the skull and is aggravated by long periods of sitting and rotation of her head. Plain radiographs are shown in Figures 36a through 36c. What is the best course of action?

Explanation

DISCUSSION: Posterior atlantoaxial arthrodesis predictably relieves pain associated with arthrosis of the atlantoaxial joints. Typically, these patients have pain at the base of the occiput and in the most cephalad portion of the posterior aspect of the neck. Associated headache is common and often severe. Pain is aggravated by rotation but usually not by flexion and extension. Diagnostic blocks of the C1-C2 joint and the greater occipital nerve may be helpful to confirm the diagnosis preoperatively.
REFERENCES: Ghanayem AJ, Leventhal M, Bohlman HH: Osteoarthrosis of the atlanto-axial joints: Long-term follow-up after treatment with arthrodesis. J Bone Joint Surg Am 1996;78:1300-1307.
Star MJ, Curd JG, Thorne RP: Atlantoaxial lateral mass osteoarthritis: A frequently overlooked cause of severe occipitocervical pain. Spine 1992;17:S71-S76.

Question 7

An obese 4-year-old boy has infantile Blount’s disease. Radiographs reveal a metaphyseal-diaphyseal angle of 18 degrees and a depression of the medial proximal tibial physis. Management should consist of

Explanation

DISCUSSION: The deformity is too severe for observation, and at age 4 years, the child is too old for orthotic treatment. To prevent recurrence, surgery should be performed before irreversible changes occur in the medial physis. A proximal tibial osteotomy should overcorrect the mechanical axis to 10 degrees of valgus. Bar resection has not been shown to be as effective in this severe deformity, especially without a concomitant osteotomy.
REFERENCES: Raney EM, Topoleski TA, Yaghoubian R, Guidera KJ, Marshall JG: Orthotic treatment of infantile tibia vara. J Pediatr Orthop 1998;18:670-674.
Loder RT, Johnston CE: Infantile tibia vara. J Pediatr Orthop 1987;7:639-646.

Question 8

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

Explanation

DISCUSSION: An os trigonum is usually asymptomatic, but this accessory bone has been associated with persistent posterior ankle pain, which has been described as os trigonum syndrome. This usually affects athletes and ballerinas. Forced plantar flexion leads to impingement of the os trigonum against the posterior tibial plafond, and flexor hallucis tendinitis may develop. It may be difficult to differentiate a fractured trigonal process from the os trigonum. MRI may reveal bone marrow edema that may aid in the diagnosis of os trigonum syndrome. Steroid injections may lead to tendon rupture. The results of excision of a symptomatic os trigonum through a posteromedial or lateral approach are favorable, with a rapid return to full function. The main complication of this procedure is sural nerve injury with a lateral approach.
REFERENCES: Hedrick MR, McBryde AM: Posterior ankle impingement. Foot Ankle Int 1994;15:2-8.
Abramowitz Y, Wollstein R, Barzilay Y, et al: Outcome of resection of a symptomatic os trigonum. J Bone Joint Surg Am 2003;85:1051-1057.

Question 9

By which mechanism can a true aneurysm of the ulnar artery result?

Explanation

Figures 1 and 2 are the radiographs of a 17-year-old boy who injured his wrist 6 months ago. He is experiencing pain and limited motion. What is the most effective treatment option?

Question 10

A 14-year-old patient has sustained a complete ACL tear of his right knee. Which of the following options has shown to be the most limiting factor for access to pediatric orthopaedic management in the United States?

Explanation

The type of health insurance in the pediatric population has shown to be a significant factor for access to specialized healthcare in the United States.
Access to pediatric orthopaedic management has been well investigated. Numerous Level 4 studies have shown that orthopaedic offices in urban and rural areas prefer treating patients with private insurance over patients with Medicaid.
Iobst et al. telephoned 100 urban and rural orthopaedic outpatient offices to schedule an appointment for a 10-year-old patient with a forearm fracture. They showed that 8/100 offices would schedule an appointment within 1 week to the child with Medicaid insurance, as compared to 36/100 that gave an appointment to a child with private insurance.
Pierce et al. contacted 42 orthopaedic practices to schedule an appointment for a 14-year-old patient with an ACL injury. They showed that 38/42 offices scheduled an appointment for the child within 2 weeks with private insurance. This compared to 6/42 that scheduled an appointment for a similar child with Medicaid.
Incorrect Answers:

Question 11

Figures 1 and 2 are the radiographs of a 20-year-old college multisport athlete who has had longstanding pain in his left hip. He denies any specific event that initiated his pain, but he notes that he had hip problems when he was an infant. He denies pain with activities of daily living, but he believes his pain is increasingly limiting his ability to exercise. He localizes the pain to his groin. He denies low-back or buttock pain or pain that radiates down his leg. What is the most likely diagnosis for the source of this patient's pain?

Explanation

This patient has cam-type femoroacetabular impingement. Decreased internal rotation and a positive impingement test (forced flexion, adduction, and internal rotation) are classic findings. The lack of pain with resisted hip flexion makes hip flexor strain unlikely, and the lack of tenderness at the greater trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement. Surgical treatment for cam impingement can be effective for symptomatic patients. Even among high-level athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable with those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment. Byrd and Jones described five patients who developed transient neurapraxias that resolved uneventfully. The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a periacetabular osteotomy can develop a more retroverted acetabulum as well.

Question 12

What is the most important sign of impending modulation with rapid progression of a spinal deformity in neurofibromatosis?

Explanation

DISCUSSION: Rib penciling is the only singular factor; 87% of the curves progressed significantly in patients with three or more penciled ribs. Modulation in neurofibromatosis scoliosis implies the change from an idiopathic type to a dysplastic type of curve with rapid progression and the need for aggressive stabilization by fusion.
REFERENCES: Crawford AH, Schorry EK: Neurofibromatosis in children: The role of the orthopaedist. J Am Acad Orthop Surg 1999;7:217-230.
Durrani AA, Crawford AH, Chouhdry SN, et al: Modulation of spinal deformities in patients with neurofibromatosis type 1. Spine 2000;25:69-75.

Question 13

A 25-year-old man sustained an L1 compression fracture in a fall from his roof. He is neurologically intact and has no other injuries. Radiographs reveal a 25% loss of height anteriorly and 5 degrees of kyphosis at the fracture site. A CT scan reveals no compromise of the posterior column. Management should consist of

Explanation

DISCUSSION: The patient has a stable fracture that can be initially treated with bed rest, followed by bracing and quick mobilization. The outcome is good and surgery is not required. These fractures can be treated nonsurgically if there is less than 50% compression, 15 degrees of angulation, and intact posterior structures.
REFERENCES: Cantor JB, Lebwohl NH, Garvey T, Eismont FJ: Nonoperative management of stable thoracolumbar burst fractures with early ambulation and bracing. Spine 1993;18:971-976.
Rechtine GR II, Cahill D, Chrin AM: Treatment of thoracolumbar trauma: Comparison of complications of operative versus nonoperative treatment. J Spinal Disord 1999;12:406-409.

Question 14

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

Explanation

DISCUSSION: Although thoracic disk herniations have been reported at all levels of the thoracic spine, more than two thirds are found at T9-T12, which is the more mobile lower third of the thoracic region.
REFERENCES: Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine. Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.
Bohlman HH, Zdeblick TA: Anterior excision of herniated thoracic discs. J Bone Joint Surg Am 1988;70:70-77.

Question 15

At what age does the lateral epicondyle normally ossify in males?

Explanation

The lateral epicondylar epiphysis is the last to ossify in the elbow at age 12 to 14 years in males. The first secondary ossification center to ossify is the capitellum, which ossifies during the first 6 months of life. Next is the radial head, ossifying between age 3 and 6 years. The medial epicondyle appears between 5 and 7 years; the trochlea and olecranon at 8 and 10 years, respectively. In females, the appearance of ossification centers is about a year earlier than males.

Question 16

Plate fixation of olecranon fractures is recommended over tension band wire fixation when

Explanation

Tension band wire fixation of olecranon fractures is recommended for fracture patterns that are proximal to the coronoid process and are relatively transverse to withstand compressive forces. When comminution is present, a neutralization technique such as plating is preferred over a compressive technique such as tension band wire fixation. Such neutralization plating, if performed correctly, does not have the risk of narrowing the sigmoid notch as tension band wire fixation would. Fractures of the tip of the olecranon, transverse fractures, fractures associated with osteoporosis, and displaced fractures are all relative indications for tension band wire fixation.

Question 17

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 18

Physiologic bowing of the lower extremities should spontaneously correct by what age?

Explanation

DISCUSSION: Physiologic bowing is common and benign. Bowing is typically symmetric, involves both the femur and tibia, and is usually most prominent in toddlers. It usually resolves by 2 years of age but there is great variability. By age 36 months, almost all children will correct spontaneously. In children with physiologic bowing, the screening examination is typically normal and a family history is absent; therefore, radiographs are not necessary. If the deformity has not resolved by age 2 years, an AP radiograph of the lower limbs should be obtained. This provides documentation of the severity of the bowing, permits measurement of the metaphyseal-diaphyseal angle and/or Langenskiold grade, and allows evaluation for conditions such as rickets or bony dysplasia. No treatment is indicated for physiologic bowing.
REFERENCES: Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, p 7.
Salenius P, Vankka E: The development of the tibiofemoral angle in children. J Bone Joint Surg Am
J V :

Question 19

A 3-year old child from an isolated mountain area is evaluated for multiple medical problems, including vomiting, loss of appetite, polyuria, and failure to thrive. History reveals the child was normal at birth. The parents, who appear healthy, are second cousins and have two other children who are normal. The parents state that they know of another family member who died at age 6 years after a similar medical history. Radiographs of the lower extremities show bowing of the long bones with cupping and widening of the physes. What is the most likely diagnosis?

Explanation

Hypophosphatemia-The patients who were symptomatic had obtundation,
hemolytic anemia, rhabdomyolysis, and hepatocellular injury that began during refeeding and resolved with treatment. The signs and symptoms, pathophysiology, and treatment of refeeding hypophosphatemia are reviewed.
Renal Osteodystrophy-Musculoskeletal complications in patients with chronic renal failure are common and may be related to the disease itself or to treatment. The altered metabolism in patients with chronic renal failure leads to renal osteodystrophy, which consists of osteomalacia and secondary hyperparathyroidism [1]. Erosive changes attributable to secondary hyperparathyroidism may be easily confused with rheumatoid arthritis, seronegative spondyloarthropathies, infection, or even malignancy.
Primary Hyperparathyroidism-Preferential involvement of cortical bone with apparent preservation of cancellous bone in primary hyperparathyroidism was confirmed by percutaneous bone biopsy. Over 80% of patients had a mean cortical width below the expected mean, whereas cancellous bone volume in over 80% of patients was above the expected mean.
Skeletal disease in primary hyperparathyroidism J Bone Miner Res 1989 Jun; 4(3):283-91
Nutritional vitamin D deficiency-Rickets, osteomalacia, and renal osteodystrophy are disorders of the mineralization of bone that result from a lack of available calcium, phosphorus, or both. The diseases that result from numerous mechanisms present with a symptom-sign-radiographic complex with such a high degree of stereotypy that laboratory investigation is often required to distinguish one form from another. The disorders in children, known as rickets, produce bowing and other deformities of the long bones and dwarfism. These disorders are principally related to the profound effect of the deficiency states on the epiphyseal plate; whereas the same disorders in adults produce an often severe osteopenia and pathologic fractures. Because of newer developments in our understanding of the factors affecting calcium-phosphorus
hemostasis and vitamin D metabolism, many of the children and Rickets, osteomalacia, and renal osteodystrophy.

Question 20

Which of the following anatomic structures is labeled 6 in Figure 27?

Explanation

DISCUSSION: The line labeled 6 points to the A2 pulley. This structure is the condensation of the digital flexor tendon sheath corresponding to the proximal aspect of the proximal phalanx. Grayson’s ligament is volar to the digital nerve and artery. Cleland’s ligament is dorsal to the digital nerve and artery. The sagittal band anchors the extensor tendons over the metacarpophalangeal joints. The triangular ligament connects the lateral bands just proximal to the terminal tendon inserting onto the base of the distal phalanx.
REFERENCES: Hollinshead WH: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, p 467.
Tubiana R, McCullough CJ, Masquelet AC: An Atlas of Surgical Exposures of the Upper Extremity. Philadelphia, PA, JB Lippincott, 1990, p 309.

Question 21

A coach of 3 football teams—the B team, junior varsity team, and varsity team—wants to study the average times in the 40-yard dash for his players. Which test would help him determine if the mean 40-yard dash times for the athletes on 1 team are different from those on the other teams?

Explanation

DISCUSSION
Data collected in research studies fall into 1 of 2 categories—continuous or discrete. Continuous data can be displayed on a curve. Examples include height, weight, and time recorded in a 40-yard dash. Discrete data represent data that fall into specific categories such as gender or the presence or absence of a risk factor.
ANOVA is used to determine statistical significance in mean values of continuous data when there are more than 2 independent samples. The 2-sample t test compares mean values of continuous data between 2 independent groups. The Chi-square test and Fisher's exact tests are tests used to analyze discrete data.
RESPONSES FOR QUESTIONS 58 THROUGH 61
Paresthesias in the fourth and fifth digits
Numbness on the lateral side of the forearm
Heterotopic ossification
Posterolateral rotatory instability of the elbow
Medial antebrachial cutaneous neuroma
For each surgical case described below, match the most likely related complication listed above.

Question 22

A 50-year-old competitive tennis player sustained a shoulder dislocation after falling on his outstretched arm 3 weeks ago. He now reports that he has regained motion but continues to have painful elevation and weakness in external rotation. A subacromial cortisone injection provided 3 weeks of relief, but the pain has returned. Which of the following studies will best aid in diagnosis?

Explanation

DISCUSSION: Based on these findings, the most likely diagnosis is a rotator cuff injury and probable tear; therefore, MRI is the study of choice. CT is preferred for articular fractures. A bone scan is nonspecific and can identify inflammation or occult fracture. Joint aspiration is not likely to identify an effusion. Physical therapy and a functional capacity examination are used to identify weakness during recovery prior to a return to work or sports.
REFERENCES: Hawkins RJ, Bell RH, Hawkins RH, Koppert GJ: Anterior dislocation of the shoulder in the older patient. Clin Orthop 1986;206:192-195.
Matsen FA III, Thomas SC, Rockwood CA: Anterior glenohumeral instability, in Rockwood CA, Matsen FA III (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, pp 526-622.

Question 23

In the treatment of thoracolumbar idiopathic scoliosis using an anterior single rod technique with interbody cages, which of the following variables has been associated with pseudoarthrosis. Review Topic

Explanation

In select patients with thoracolumbar idiopathic scoliosis, an anterior approach with a single rod and interbody cages may be indicated. Thoracic hyperkyphosis (>40 degrees ) is a risk factor for pseudoarthrosis in patients treated with this method.
In a prospective study, Sweet et al found anterior instrumented fusions using a single solid rod had good radiographic and clinical outcomes. In their treatment group they found common risk factors for pseudarthrosis were smoking, weight >70 kg, and T5-T12 hyperkyphosis of > 40 degrees. They recommend consideration should be given to alternate techniques in larger adolescents (>70 kg) with thoracic hyperkyphosis (>40 degrees ). The average coronal correction of thoracic curves was from 55 degrees to 29 degrees (47%). The average correction of thoracolumbar/lumbar curves was from 50 degrees to 15 degrees (70%). Neither of these variables were associated with pseudoarthrosis. In the sagittal plane, lordosis was maintained in thoracolumbar/lumbar fusions at -58 degrees (T12-sacrum). Improved maintenance of lumbar lordosis is considered one of the advantages of an anterior approach.
In an additional study from the same group at Wash U, Hurford et al designed a study to compare the results of anterior DUAL-rod instrumentation with their previous experience using single-rod constructs. They found the two technique were comparable in the amount of radiographic deformity correction obtained. However, they report the absence of any pseudarthroses in the 60 patients with dual-rod is a distinct advantage over the single rod technique.

Question 24

A 55-year-old man was injured when a large piece of sheet metal lacerated his medial elbow while working at a factory. He underwent primary repair of the lacerated structures shown in Figures 1 and 2 on the day of injury. In addition to this surgical treatment, what nerve transfer procedure should be considered during this primary operative intervention to improve his functional recovery?

Explanation

EXPLANATION:
In adults, the repair of high ulnar nerve injuries typically yields incomplete motor recovery and disappointing functional results despite early surgical intervention and careful surgical technique. Early transfer of the terminal branch of the AIN to the deep ulnar motor fascicle can rapidly reinnervate distal targets and potentially preserve motor end plate function in the intrinsic musculature of the hand because of the proximity of the nerve transfer to the target muscle. Sensory deficits due to an ulnar nerve injury
can be restored through a transfer of median sensory fascicles to the distal ulna sensory fascicles. This procedure typically would not be considered at the time of the original surgery, because sensory recovery is more likely than motor recovery in the setting of a high ulnar nerve injury. For radial nerve injuries, wrist extension can be restored through an FDS branch of the median nerve transfer to the ECRB branch of the radial nerve. The FCU fascicle of the ulnar nerve can be transferred to the biceps branch of the musculocutaneous nerve to restore elbow flexion and supination.

Question 25

A 39-year-old man has had persistent right shoulder pain for the past 6 months. A formal physical therapy program has failed to provide relief, and an injection several months ago provided only short-term relief. Examination reveals a positive Neer and Hawkins test. There is no instability and the neurovascular examination is normal. Arthroscopy reveals a partial rotator cuff tear on the bursal side measuring 60% of the tendon thickness. What is the next most appropriate step in management?

Explanation

DISCUSSION: Although arthroscopic debridement with or without subacromial decompression is a reasonable response, the patient has positive impingement signs. Several recent studies regarding the surgical treatment of partial rotator cuff tears have demonstrated good to excellent results after repair of tears involving more than 50% of the tendon thickness. This was shown specifically for bursal-sided tears and joint-side tears. Biceps tenotomy is not indicated in a young patient.
REFERENCES: Matava MJ, Purcell DB, Rudzki JR: Partial-thickness rotator cuff tears.

Am J Sports Med 2005;33:1405-1417.
Fukuda H: The management of partial-thickness tears of the rotator cuff. J Bone Joint Surg Br 2003;85:3-11.

Question 26

A lO'/z-year-old boy sustained the injury shown in Figure 72 when he fell out of a tree. This is a closed, neurologically intact injury and the patient has no head injury or loss of consciousness. He weighs 115 pounds and is otherwise healthy. What is the optimal treatment option for this injury?

Explanation

DISCUSSION: Although flexible intramedullary nails are a good treatment alternative for femoral shaft fractures in older children, patients weighing more than 100 pounds have a higher incidence of complications that include bending of the nails. Therefore, transtrochanteric solid intramedullary nail fixation is most likely the best option for this patient. Using a greater trochanteric entry point avoids the piriformis fossa and the possibility of osteonecrosis. External fixation is not a good alternative for this patient because of the transverse nature of the fracture. External fixation of this fracture pattern has been associated with a high refracture rate. Traction and casting can be performed but results in a lengthy hospital stay and a very large cast in an overweight 10-year-old child.
REFERENCES: Flynn JM, Schwend RM: Management of pediatric femoral shaft fractures. J Am Acad Orthop Surg 2004;12:347-359.

Gordon JE, Swenning TA, Burd TA, et al: Proximal femoral radiographic changes after lateral transtrochanteric intramedullary nail placement in children. J Bone Joint Surg Am 2003;85:1295-1301.
Figure 73a Figure 73b

Question 27

After performing a total hip arthroplasty through a posterolateral approach, an orthopaedic surgeon is unable to adequately externally rotate the leg and subsequently exposes the anterior capsule. When releasing the inferior aspect of the anterior capsule, pulsatile bleeding is encountered. A branch of which artery is most likely lacerated?

Explanation

DISCUSSION
Branches of the lateral femoral circumflex artery arise from the inferior aspect of the anterior hip capsule. They can be injured when removing the anterior capsule from any approach. The inferior gluteal artery supplies the gluteus maximus. The medial femoral circumflex artery enters the hip joint along the path of the obturator externus tendon. The femoral artery crosses the anterior hip joint in the superior-to-inferior direction and is located just medial to the hip joint.

Question 28

A 42-year-old man who is right-hand dominant injured his right shoulder when he fell from a ladder onto his outstretched arm 1 hour ago. Radiographs reveal a two-part greater tuberosity anterior fracture-dislocation. Initial management should consist of

Explanation

DISCUSSION: Greater tuberosity anterior fractures associated with anterior glenohumeral dislocations respond very well to closed methods in the majority of patients. Closed reduction of the glenohumeral joint often anatomically reduces the greater tuberosity into its cancellous bed, without the need for open fixation or cuff repair. Once closed reduction of the joint is performed, tuberosity displacement and joint articulation should be evaluated radiographically with AP and scapular lateral views as well as an axillary view. The axillary view will not only definitively show the joint articulation but also demonstrate posterior displacement of the greater tuberosity missed on the AP and lateral views. If no or minimal (5 mm) displacement is found, then nonsurgical management consisting of a sling and gentle passive range-of-motion exercises can be instituted.
REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.
Flatow EL, Cuomo F, Maday MG, Miller SR, McIlveen SJ, Bigliani LU: Open reduction and internal fixation of two-part displaced fractures of the greater tuberosity of the proximal part of the humerus. J Bone Joint Surg Am 1991;73:1213-1218.

Question 29

Figure A is the lateral view of a left knee cadaveric specimen that has the extensor mechanism removed. Which two structures labeled provide the most rotational stability in knee flexion? Review Topic

Explanation

The politeus tendon (C) and the popliteofibular ligament (D) are the lateral knee structures that provide the most rotational stability in knee flexion. The lateral collateral ligament (B) provides varus stability and rotational stability in knee
extension.
The lateral knee is stabilized by 28 unique static and dynamic structures. These structures work in concert to resist varus gapping and rotational knee instability. The three primary stabilizers include the fibular or lateral collateral ligament (LCL), the popliteus tendon (PT) and the popliteofibular ligament (PFL). Injury to these ligaments results in increased forces seen on ACL and PCL ligament reconstruction grafts with combined posterolateral corner (PLC) injuries, which can result in graft failure if the PLC is not reconstructed as well.
James et al reviewed the anatomy and biomechanics of the lateral knee stabilizers, detailing the specific functional contributions of the individual structures. The LCL is the primary restraint to varus instability, the highest forces occurring at knee extension (0°-30°). The PT and PFL serve as restraints to rotational instability, the highest forces occurring at knee flexion (60°-90°).
LaPrade et al reviewed the anatomy and biomechanics of the medial knee stabilizers. The three key static stabilizers are the superficial medial collateral ligament (sMCL), the deep medial collateral ligament (dMCL), and the posterior oblique ligament (POL). The sMCL is the primary restraint to valgus instability (proximal sMCL) and secondary restraint to rotational instability (distal sMCL) at all knee flexion angles. The dMCL is a secondary restraint to valgus and rotational instability. The POL is the primary restraint to rotational instability.
Figure A depicts the lateral knee structures in a cadaver specimen (A = lateral meniscus, B = LCL, C = PT, D = PFL, E = lateral head of gastrocnemius). Illustration A is a labeled picture of the lateral knee structures. Illustration B is a table from James et al demonstrating the change in forces experienced by the different lateral stabilizers at varying degrees of knee flexion. You see the LCL resists rotation at 0°-30° (extension) while the PT and PFL resist rotation at 60°-90° (flexion).
Incorrect Responses:

Question 30

Halo treatment for preadolescent children typically requires the use of which of the following? Review Topic

Explanation

The complication rate with halo vest treatment in children is reported to be as high as 68% in contrast to a 36% complication rate in adults. These complications include not only pin tract infections, but also skull penetration. Multiple pins allow for the early removal of pins without fixation consequences should pin site infections begin to develop. Moreover, there is significant variability in the insertional torque applied by a variety halo pin torque wrenches, including those from the same manufacturer. Consequently, the use of a large number of pins (8 to 12) placed a very low insertional torque (1 to 5 in-lb) in children is recommended. A CT scan of the head should also be considered to assess for the thickest areas of the skull suitable for pin application.

Question 31

Figure 26 shows the radiograph of a 48-year-old woman who has right arm pain and hematuria. A bone scan reveals increased uptake in the left ribs and thoracic spine. A needle biopsy specimen shows that the lesion is highly keratin positive and composed primarily of clear cells. What is the best course of action?

Explanation

DISCUSSION: The lesion has the typical “blown out” lytic radiographic appearance that is most commonly found in thyroid or renal cell metastases. Given the history of hematuria and histology findings, the most likely diagnosis is metastatic renal cell carcinoma. This tumor is relatively resistant to chemotherapy. Radiation therapy is used as a postoperative adjuvant treatment with varying response rates. Surgery should be performed after preoperative embolization to decrease the risk of intraoperative bleeding, as no tourniquet can be used in this location. Patients with metastatic renal cell carcinomas may survive for years, resulting in a higher likelihood of local tumor progression with ineffective adjuvant therapy. Intramedullary fixation combined with curettage and cementation will provide the best chance of local control while maintaining the patient’s native shoulder and elbow joints. A total humeral resection is an extensive surgery with considerable morbidity and is not indicated for this patient because less extensive surgery is likely to be effective.
REFERENCES: Harrington KD, Sim FH, Enis JE, Johnston JO, Diok HM, Gristina AG: Methylmethacrylate as an adjunct in internal fixation of pathological fractures: Experience with three hundred and seventy-five cases. J Bone Joint Surg Am 1976;58:1047-1054.
Sun S, Lang EV: Bone metastases from renal cell carcinoma: Preoperative embolization. J Vasc Interv Radiol 1998;9:263-269.
Katzner M, Schvingt E: Operative treatment of bone metastases secondary to renal carcinoma: Basic research and treatment of renal cell carcinoma metastasis. Prog Clin Biol Res EORTC 1990;348:151-168.

Question 32

A skeletal survey is more accurate than a bone scan for detecting skeletal involvement in which of the following neoplastic diseases?

Explanation

Multiple Myeloma lesions are cold on bone scan and because of this a skeletal survey is more useful.

Question 33

What is the most common nonanesthetic-related reversible cause of changes in intraoperative neurophysiologic monitoring data?

Explanation

DISCUSSION: Patient positioning that results in local nerve compression, plexus traction, or improper neck alignment is the most common nonanesthetic-related cause of changes in intraoperative neurophysiologic monitoring data during spinal surgery.
REFERENCES: Jones SC, Fernau R, Woeltjen BL: Use of somatosensory evoked potentials to detect peripheral ischemia and potential injury resulting from positioning of the surgical patient: Case reports and discussion. Spine J 2004;4:360-362.
Schwartz DM, Sestokas AK, Hilibrand AS, et al: Neurophysiological identification of position-induced neurologic injury during anterior cervical spine surgery. J Clin Monit Comput 2006;20:437-444.

Question 34

Figures below show the radiographs obtained from a 79-year-old woman who has been experiencing increasing tibial pain 10 years after undergoing revision total knee arthroplasty. No evidence of infection is seen. What is the most appropriate treatment?

Explanation

DISCUSSION:
Stems are available for cemented and press-fit implantation. To be effective, press-fit stems should engage the diaphysis, as shown in Figures 3 and 4. They also assist in obtaining correct limb alignment. Short metaphyseal-engaging stems are associated with failure rates that range between 16% and 29%. Cemented stems may be shorter than press-fit stems, because they do not have to engage the diaphysis. Short, fully cemented stems offer the advantage of metaphyseal fixation. Hybrid stem fixation makes use of the metaphysis for cement fixation with metaphyseal cones or sleeves and diaphyseal-engaging press-fit stems.

Question 35

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

Explanation

DISCUSSION: Tibial tubercle avulsion is an injury of the adolescent knee that most often occurs just before the end of growth. The fracture usually occurs with jumping, either at push-off or landing. This patient has a type III injury. In type III injuries, the articular surface is disrupted, and meniscal injury and compartment syndrome can occur. Open reduction is the treatment of choice, and anterior fasciotomy should be considered prophylactically at the time of surgery. Although the fracture heals with an anterior epiphysiodesis of the proximal tibia, little growth remains in this patient and no special handling of the physis is warranted.
REFERENCES: Ogden JA, Tross RB, Murphy MJ: Fractures of the tibial tuberosity in adolescents. J Bone Joint Surg Am 1980;62:205-215.
Pape JM, Goulet JA, Hensinger RN: Compartment syndrome complicating tibial tubercle avulsion. Clin Orthop 1993;295:201-204.

Question 36

Figures 34a through 34c show the radiographs of a 51-year-old woman who injured her elbow in a fall from standing height. Examination reveals that elbow range of motion is limited by pain only. Management should consist of

Explanation

DISCUSSION: The radiographs show a small minimally displaced radial head fracture that is amenable to nonsurgical management. Early range-of-motion exercises will best restore

function and minimize stiffness. A long arm cast for any length of time will result in severe elbow stiffness.
REFERENCES: Morrey BF: Radial head fracture, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 341-364.
Hotchkiss RN: Displaced fractures of the radial head: Internal fixation or excision? J Am Acad Orthop Surg 1997;5:1-10.

Question 37

..Figures 83a and 83b are the radiographs of a 53-year-old otherwise healthy homemaker who had a syncopal episode and sustained a ground-level fall and injury to her right elbow. She presently admits to right elbow pain, swelling, and an inability to bend her elbow. What is the best initial treatment for this injury?

Explanation

He did not have an engaging Hill-Sachs lesion, the rotator cuff was unremarkable, and the capsule was not torn from the humerus. After surgery, he did well for 6 months until he jumped into a lake and again dislocated his shoulder anteriorly. He says his shoulder no longer felt stable after his reduction.

Question 38

A 7-year-old girl reports foot pain and has difficulty ambulating. History reveals that she fell off a scooter 1 week ago, and there is possible exposure to a tick bite. A radiograph is shown in Figure 29. What is the best course of action?

Explanation

DISCUSSION: The child has Kohler’s disease. This is a self-limiting osteochondritis of the navicular. It is treated symptomatically with initial cast immobilization for 6 to 12 weeks, followed possibly by orthotic management. Findings shown in the radiograph usually will normalize within 1 year, and there are no long-term sequelae.
REFERENCES: Borges JL, Guille JT, Bowen JR: Kohler’s bone disease of the tarsal navicular. J Pediatr Orthop 1995;15:596-598.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 65-78.

Question 39

A 32-year-old man sustains a forceful inversion injury while playing soccer. Examination reveals tenderness in the lateral hindfoot and midfoot region with associated ecchymosis and swelling. Radiographs show proximal migration of the os peroneum. Active eversion is still present. These findings indicate disruption of the

Explanation

DISCUSSION: The os peroneum is an accessory ossicle located within the peroneus longus tendon. It is typically located at the level of the cuboid groove in the lateral hindfoot and midfoot region. Proximal migration of the os peroneum indicates disruption of the peroneus longus tendon and is an important clue to diagnosis. This unusual condition can cause chronic lateral ankle pain, and surgical repair may be indicated. Active eversion indicates that the peroneus brevis is clinically intact. Disruption of the extensor digitorum brevis, plantar fascia, or syndesmosis would have no effect on the position of the os peroneum.
REFERENCES: Thompson FM, Patterson AH: Rupture of the peroneus longus tendon: Report of three cases. J Bone Joint Surg Am 1989;71:293-295.
Clanton TO: Athletic injuries to the soft tissues of the foot and ankle, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 1090-1209.

Question 40

Which of the following methods is effective in correcting recurrent dislocation following total hip arthroplasty?

Explanation

DISCUSSION: Recurrent dislocation following total hip arthroplasty is a difficult problem to correct. Studies conducted by the Mayo Clinic show a failure rate of close to 40% with surgical treatment. A variety of methods have been successful, but no specific approach has been reported to be the most predictably successful. To select and institute the proper treatment option, the cause of the dislocation must be identified. Surgical options fall into several broad categories that include increasing soft-tissue tension (trochanteric advancement or longer neck lengths) or more stable articulation (larger diameter head component, bipolar prosthesis, or a constrained component). In a series of total hip arthroplasties done with a constrained cup, the loosening rates of the cup and the stem were reported to be 6% each, comparable to a reported series of complex revision total hip arthroplasties at a similar follow-up interval.
REFERENCES: Woo RY, Morrey BF: Dislocations after total hip arthroplasty. J Bone Joint Surg Am 1982;64:1295-1306.
Goetz DD, Capello WN, Callaghan JJ, Brown TD, Johnston RC: Salvage of a recurrently dislocating total hip prosthesis with use of a constrained acetabular component: A retrospective analysis of fifty-six cases. J Bone Joint Surg Am 1998;80:502-509.

Question 41

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

Explanation

DISCUSSION: While Köhler’s disease has a benign course, temporary cast immobilization has been shown to result in a shortened duration of symptoms. Core decompression or other surgery is not warranted because of the benign nature. Shoe inserts may be beneficial, but there are no studies to support their use.
REFERENCES: Borges JL, Guile JT, Bowen JR: Köhler’s bone disease of the tarsal navicular.

J Pediatr Orthop 1995;15:596-598.
Williams GA, Cowell HR: Köhler’s disease of the tarsal navicular. Clin Orthop 1981;158:53-58.

Question 42

During particle-induced osteolysis around implants, what cell secretes most of the interleukin-6 (IL-6)?

Explanation

DISCUSSION: During osteolysis, IL-6 is secreted by fibroblasts in the membrane surrounding the prosthesis. IL-6 also can be secreted by osteoblasts in other settings, but they are not the predominant source of IL-6 in particle-induced osteolysis. The remaining cells are not major sources of IL-6.
REFERENCE: Bukata SV, Gelinas J, Wei X, et al: PGE2 and IL-6 production by fibroblasts in response to titanium wear debris particles is mediated through a Cox-2 dependent pathway. J Orthop Res 2004;22:6-12.

Question 43

A 24-year-old man who plays golf noted the immediate onset of pain on the ulnar side of his hand and has been unable to swing a club for the past 6 weeks after striking a tree root with his club during his golf swing. Examination reveals full motion of the wrist, diminished grip strength, and tenderness over the hypothenar region. A CT scan of the hand and wrist is shown in Figure 26. Management should consist of

Explanation

DISCUSSION: Fractures of the hook of the hamate frequently are not identified in the acute phase. Because the fracture can be difficult to see on plain radiographs, the lack of findings can lead to a painful nonunion. A carpal tunnel view may show the fracture, but a CT scan will best detect the injury. Immobilization is the treatment of choice and will result in union in most patients unless the diagnosis is delayed. However, excision of the fragment may be necessary for patients who have nonunion, persistent pain, or ulnar nerve palsy.
REFERENCES: Carroll RE, Lakin JF: Fracture of the hook of the hamate: Acute treatment. J Trauma 1993;34:803-805.
Whalen JL, Bishop AT, Linscheid RL: Nonoperative treatment of acute hamate hook fractures. J Hand Surg Am 1992;17:507-511.

Question 44

A 13-year-old girl has had pain in her ankle and difficulty with sporting activities for the past 6 months. Nonsteroidal anti-inflammatory drugs and use of a short leg cast have provided minimal relief. A radiograph and MRI scan are shown in Figures 43a and 43b. What is the next most appropriate step in treatment?

Explanation

DISCUSSION: The MRI scan shows an obvious talocalcaneal coalition of the medial facet. Because nonsurgical management has failed, surgical resection of the coalition is indicated. Arthrodesis would be indicated only if resection fails to relieve pain or if advanced degeneration of the hindfoot joints is present.
REFERENCES: McCormack TJ, Olney B, Asher M: Talocalcaneal coalition resection: A 10-year follow-up. J Pediatr Orthop 1997;17:13-15.
Thometz J: Tarsal coalition. Foot Ankle Clin 2000;5:103-118.

Question 45

Which of the following best characterizes the antigenicity of allograft bone?

Explanation

DISCUSSION: Cell surface glycoproteins present in the heterogeneous population of the cells within the graft are primarily responsible for the antigenicity. Macromolocules of the matrix have also been implicated. Cryopreserved grafts have less antigenicity than fresh. Freezing, freeze-drying, or chemical sterilization and antigen extraction of the bone allograft have all been shown to reduce the antigenicity of the graft. Freeze-drying of retroviral-infected cortical bone and tendon does not inactivate retrovirus. Immunosuppression has been shown to decrease response. Hematopoietic elements along with osteogenic, chondrogenic, fibrous, and vascular cells have been shown to be antigenic.
REFERENCES: Crawford MJ, Swenson CL, Arnoczky SP, et al: Lyophilization does not inactivate infectious retrovirus in systemically infected bone and tendon allografts. Am J Sports Med 2004;32:580-586.
Stevenson S, Li XQ, Davy DT, et al: Critical biological determinants of incorporation of non-vascularized cortical bone grafts: Quantification of a complex process and structure. J Bone Joint Surg Am 1997;79:1-16.
Simon SR (eds): Orthopaedic Basic Science. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 277-320.

Question 46

A right-handed 24-year-old professional baseball player injured his left shoulder 6 weeks ago when he dove forward and landed hard with the arm extended. He reports that the shoulder “slipped out” and “went back in.” The shoulder did not need to be reduced. He now reports deep pain in the front of the shoulder when batting on either side and is hesitant to raise his left arm up over his head to catch a ball. Examination reveals no obvious deformities of the shoulder and a somewhat guarded, limited range of motion in all planes. Provocative tests for the rotator cuff and labrum are equivocal. MRI scans are shown in Figures 16a and 16b. What is the best course of action?

Explanation

DISCUSSION: A hard fall on an outstretched arm often results in injury to the glenoid labrum. A significant tear of the anterior/inferior labrum often leads to instability, pain, and mechanical symptoms of the shoulder. The MRI scan shows no obvious labral tear or Hill-Sachs lesion to suggest an anterior dislocation. Recent clinical studies have suggested that early stabilization of initial anterior dislocations may lead to better results than nonsurgical management in young, athletic patients. However, there are no data to support early surgery for anterior labral tears resulting from traumatic subluxation without dislocation. Initial treatment should consist of a short period of rest and immobilization, followed by a physical therapy rehabilitation program designed to restore motion, strength, and dynamic stability to the shoulder. If the athlete cannot return to play following nonsurgical management, surgical repair of the labrum, either through an open or arthroscopic approach, is indicated. There is no role for immediate thermal capsular shift in this setting.
REFERENCES: Abrams JS, Savoie FH III, Tauro JC, et al: Recent advances in the evaluation and treatment of shoulder instability: Anterior, posterior and multidirectional. Arthroscopy 2002;18:1-13.
DeBerardino TM, Arciero RA, Taylor DC, et al: Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes: Two- to five-year follow-up. Am J Sports Med 2001;29:586-592.

Question 47

A 5-year-old boy complains of atraumatic foot pain that is aggravated by weight-bearing and an antalgic limp for a few days. He is splinted for 2 weeks by his pediatrician and referred to your office. Examination is unremarkable. Radiographs are shown in Figures A through C. What is the next best step? Review Topic

Explanation

Delayed motor milestones, and cardiac and renal work up are necessary
Normal motor milestones, but cardiac and renal work up are necessary
Delayed motor milestones, but no further work up is necessary
Normal motor milestones, and no further work up is necessary
No chance of passing on this trait to children, as it results from a spontaneous genetic mutation
This patient has post-axial polydactyly of the feet. Children with this condition exhibit normal motor milestones. If the remainder of the physical examination is normal, no further work up is necessary.
Post-axial polydactyly is a common autosomal dominant trait. As such, there is usually a family history. In the absence of other physical exam abnormalities, this condition is not associated with systemic disorders. Normal motor development can be expected, though surgical treatment may be undertaken to facilitate cosmesis or shoe-wear.
Phelps et al. reviewed supernumerary digits in 61 patients at an average of 15 year follow up. They found 94% good to excellent results. Poor results were associated with pre-axial duplications and persistent hallux varus.
Figure A is a clinical photo showing bilateral post-axial polydactyly of the foot. Incorrect answers:
cardiac or renal conditions without any manifestations. Answer 5. This is an autosomal dominant condition.

Question 48

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

Explanation

DISCUSSION: MRI arthrography is the imaging study of choice for evaluation of medial collateral ligament injuries.
REFERENCES: Carrino JA, Morrison WB, Zou KH, et al: Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: Prospective evaluation of two-dimensional pulse sequences for detection of complete tears. Skeletal Radiol 2001;30:625-632.
Munshi M, Pretterklieber ML, Chung CB, et al: Anterior bundle of ulnar collateral ligament: Evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004;231:797-803.

Question 49

..Figures 78a and 78b are the radiographs of a 47-year-old right-hand-dominant woman who has a 3-month history of gradually progressive right shoulder pain. She reports no previous trauma, but does report pain at night and with activity such as weight training. Examination demonstrates active and passive range of motion to be 110 degrees forward elevation, external rotation to 20 degrees, and internal rotation to the sacrum. The next treatment step should include

Explanation

RESPONSES FOR QUESTIONS 79 THROUGH 82
Rotator cuff and scapular stabilizer strengthening exercises
Diagnostic and therapeutic corticosteroid injection
Arthroscopic debridement
Completion of rotator cuff tear, repair, and biceps tenotomy
Acromioplasty
Repair of rotator cuff and superior labrum anterior to posterior (SLAP) repair

Repair of subscapularis tendon and biceps tenodesis

Question 50

Figures below show the radiographs obtained from an 86-year-old-woman who has had chronic left hip pain for several years. She now uses a walker and a wheelchair for ambulation. She is medically healthy. What is the most appropriate surgical intervention?

Explanation

DISCUSSION:
This 86-year-old woman has poor bone quality and osteoarthritis of the left hip. Her lateral radiograph confirms Dorr type C bone quality. A hybrid left THA with a cemented femoral stem would be the treatment of choice.

Question 51

Figures below demonstrate the radiographs obtained from a 35-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. A further work-up reveals elevations in serum cobalt and chromium levels and fluid collections surrounding the hip on MRI with MARS. Revision THA is recommended. The most common complication following revision of a failed metal-on-metal hip arthroplasty is

Explanation

THA has proven durable and reliable for pain relief and improving function for 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. With its capacity to offer 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 with potential transfer of metal ions across the placental barrier make metal-on-metal bearings less desirable and relatively contraindicated for younger women of childbearing age. The workup of a painful metal-on-metal hip arthroplasty necessitates a systematic approach. Several algorithms have been proposed. Routine laboratory studies including sedimentation rate, CRP, and serum cobalt and chromium ion levels should be obtained for all patients with pain. Advanced imaging including MARS MRI 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 cellcounts. 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 revision of failed metal-on-metal hip replacements.

Question 52

Which of the following activities can improve posterior capsular contractures?

Explanation

DISCUSSION: Posterior capsule stretching is performed in the cross-chest and behind the back positions. Stretching in internal rotation in the abducted shoulder will further stretch the posterior capsule. Wide grip stretch, and anterior capsule and strengthening exercises will not necessarily stretch the capsule.
REFERENCES: Ellenbacher TS: Shoulder internal and external rotation strength and range of motion of highly-skilled junior tennis players. Isokinetic Exercise Sci 1992;2:1-8.
Kibler WB, McMullen J, Uhl J: Shoulder rehabilitation strategies, guidelines, and practice. Op Tech Sports Med 2000;8:258-267.

Question 53

A patient reports hyperesthesia over the base of the thenar eminence following volar locked plating of a distal radius fracture. A standard volar approach of Henry was used. What is the most likely cause of the hyperesthesia?

Explanation

DISCUSSION: The palmar cutaneous branch of the median nerve separates from the median nerve approximately 4 to 6 cm proximal to the wrist crease and travels between the median nerve and the flexor carpi radialis tendon. It supplies the skin of the thenar region. This nerve is at risk for injury with retraction of the digital flexor tendons in plating the distal radius. Wartenberg’s syndrome is compression of the superficial radial nerve which innervates the dorsum of the thumb and the first dorsal web space. Carpal tunnel syndrome causes dysesthesias of the thumb, index, and/or middle fingers. C7 radiculopathy affects the index and middle fingers.
REFERENCES: Jupiter JB, Fernandez DL, Toh CL, et al: Operative treatment of volar intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1996;78:1817-1828.
Hoppenfield S, deBoer P (eds): Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 2. Philadelphia, PA, JB Lippincott, 1994, pp 156-176.

Question 54

A teenager is undergoing a correction of deformity and lengthening of the femur. Distractions are proceeding as expected; however, during his 6-week follow-up examination, the patient reports that the distraction motors have become harder to turn over for the past 2 to 3 days. Figures 37a and 37b show current radiographs. What is the most likely complication being encountered?

Explanation

DISCUSSION: Premature consolidation is a complication that is unique to gradual bone lengthening after corticotomy. Causes include excessive latency period, inadequate distraction rate, exuberant bone formation, patient compliance problems, and mechanical failure of the distraction apparatus. The femur and fibula are most commonly involved. This patient did not have an incomplete corticotomy, as initial distraction occurred before the distraction device was noted to seize up. The radiographs show bowing of the Ilizarov wires and mature regenerate bone, both suggestive of premature consolidation. No wire breakage or joint subluxation is seen on the radiographs. Treatment for premature consolidation includes continuing distraction until the consolidation bridge ruptures, or additional surgery may include closed rotational osteoclasis or repeat corticotomy.
REFERENCES: Paley D: Problems, obstacles and complications of limb lengthening, in Maiocchi AB, Aronson J (eds): Operative Principles of Ilizarov. Baltimore, MD, Williams & Wilkins, 1991, p 360.
Herring JA: Limb length discrepancy, in Herring JA (ed): Tachdjian’s Pediatric Orthopaedics,

ed 3. Philadelphia, PA, WB Saunders, 2002, p 1088.

Question 55

A 55-year-old male returns for followup 3 months after reverse shoulder arthroplasty. He reports limited function of his right shoulder but no antecedent trauma. A radiograph of his shoulder is shown in Figure A. All of the following variables are associated with this complication EXCEPT: Review Topic

Explanation

Rheumatoid arthritis is not associated with reverse shoulder arthroplasty (RSA) dislocation.
RSA dislocation is a known complication of RSA. Risks include proximal humeral bone loss, chronic fracture sequelae with malunited/ununited tuberosities, failed previous arthroplasty, and fixed glenohumeral dislocation preoperatively. An irreparable subscapularis tears may be less of an issue with newer implant designs.
Trappey et al. studied instability and infection rates after RSA. They found that the rate of instability was similar in primary and revision surgery, but the rate of infection was higher in revision surgery. Instability was highest in the fracture sequelae group because of malunited tuberosities, contractures and proximal humeral bone loss.
Favre et al. examined the effect of component positioning on RSA stability. They found that humeral version was more important than glenoid version. Stability is improved with the humerus in neutral or slight anterversion. They recommend avoiding retroversion >10deg.
Edwards et al. examined subscapularis insufficiency and the risk of RSA dislocation. They found that of 138 RSA, all 7 dislocations occurred in patients with an irreparable subscapularis. Dislocation was also more likely in patients with complex diagnoses, including proximal humeral nonunion, fixed dislocation, and failed prior arthroplasty.
Figure A shows reverse shoulder arthroplasty dislocation. Incorrect Answers:

Question 56

A 56-year-old laborer sustained a subcoracoid dislocation of the shoulder as a result of falling off a scaffold 3 weeks ago. He now is unable to actively raise his arm and has constant pain. What is the most likely diagnosis?

Explanation

Thirty-one patients who were unable to abduct the involved arm after reduction of a primary anterior dislocation of the glenohumeral joint were found to have a ruptured rotator cuff. In their series, the incidence of injury to the axillary nerve was 7.8% as compared with 100% for rupture of the rotator cuff.

Question 57

Figure 93 shows the axial T2-weighted MRI scan of the lumbar spine of a 70-year-old man. The arrow points to which of the following structures? Review Topic

Explanation

The ligamenta flava (singular, ligamentum flavum, Latin for yellow ligament) are ligaments that connect the laminae of adjacent vertebra, all the way from the axis to the first segment of the sacrum. In T2-weighted sequencing, ligamentous structures possess a low signal intensity. The ligamentum in this patient is markedly thickened, resulting in severe spinal stenosis. The epidural space lies ventral and medial to the ligamentum flavum and should possess a high signal intensity secondary to the presence of cerebrospinal fluid. However, in the case of high-grade stenosis, there may be little if any cerebrospinal fluid present, making the epidural space and central canal difficult to identify. A lumbar synovial cyst should also have high signal intensity because of the presence of synovial fluid.
(SBQ12SP.14) A 36-year-old male presents with acute onset of right buttock and leg pain following lifting a heavy object. On physical exam he has weakness to knee extension, numbness over the medial malleolus, and a decreased patellar reflex. Which of the following would most likely explain this clinical presentation. Review Topic
Lumbar arachnoiditis
L4/L5 paracentral disc herniation
L3/L4 far lateral (foraminal) disc herniation
L4/L5 far lateral (foraminal) disc herniation
L5/S1 far lateral (foraminal) disc herniation
The clinical presentation is consistent with a L4 radiculopathy. A L4/L5 far lateral (foraminal) disc herniation would compress the exiting root (L4) and cause these symptoms.
The location of a prolapsed lumbar disc determines its symptoms. Central disc herniations may give rise to back pain or cauda equina syndrome. Paracentral disc herniations (90-95% of cases) affect the traversing nerve root. Far lateral disc herniations (5-10%) affect the exiting nerve root.
Gregory et al. summarize physical signs in lumbar disc herniation. They state that the straight-leg-raise is the most sensitive (73-98% sensitive) test and the crossed straight-leg-raise is the most specific (88-98% specific) test for lumbar disc herniation. Other specific tests include weak ankle dorsiflexion (89% specific), absent ankle reflex (89% specific), and calf wasting (94% specific, but a late finding).
Illustration A shows how a paracentral L4/L5 disc herniation affects the traversing L5 root, but a far lateral L4/L5 disc herniation affects the L4 root. Illustration B shows the dermatomal distribution of pain with root involvement from L3 to S1.
Incorrect Answers:

Question 58

Figure A shows the 2 bundles of the ACL dissected from a cadaveric knee off their bony attachments. They are labeled Bundle A and Bundle B, respectively. Which of the following is true? Review Topic

Explanation

Bundle A is the anteromedial (AM) bundle, which is longer, and is tight in flexion. Bundle B is the posterolateral (PL) bundle, which is shorter, and is loose in flexion. The AM bundle is attached anterior to the PL bundle on the tibia.
The ACL is comprised of 2 bundles. The AM bundle is longer than the PL bundle.
Their names reflect their relative anatomic positions on the tibial insertion site. On the femur, the AM bundle begins at the proximal-anterior aspect of the femoral insertion site, while the PL bundle begins at the posterior-inferior part. In flexion, the AM bundle is tight and the PL bundle is loose. In extension, the AM bundle is loose and the PL bundle is tight.
Bicer et al. reviewed the anatomy of the ACL. They found that the AM bundle was longer (32mm) compared with the PL bundle (18mm). PL bundle carries greater force near full extension, and the AM bundle carries greater force after 15-45° of flexion. Under combined rotatory loads (valgus and internal tibial torque at knee flexion
>30°), the AM bundle bore more force than the PL bundle.
Figure A shows the 2 bundles of the ACL. The AM bundle is longer than the PL bundle. The oft referred to length of ACL refers mainly to the length of the AM bundle. Illustrations A and B show the spatial relationships of the AM and PL bundles in a cadaveric knee. Illustration C shows the relative positions of the attachments of each bundle.
Incorrect

Question 59

Which of the following conditions is associated with palmoplantar pustulosis?

Explanation

DISCUSSION: Sternoclavicular hyperotosis is a seronegative and HLA-B27 negative rheumatic disease. In this condition, hyperostosis may appear in the spine, long bones, sacroiliac joints, and the sternoclavicular region. This entity is also associated with palmoplantar pustulosis.
REFERENCES: Wirth MA, Rockwood CA: Disorders of the sternoclavicular joint, in Rockwood CA, Matsen FA, Wirth MA, et al (eds): The Shoulder. Philadelphia, PA,

WB Saunders, 2004, vol 2, pp 608-609.
Sonozaki H, Azuma A, Okai K, et al: Clinical features of 22 cases with inter-sterno-costo-clavicular ossification: A new rheumatic syndrome. Arch Orthop Trauma Surg 1979;95:13-22.

Question 60

Figures 9a and 9b are the radiographs of a 19-year-old woman with a painful juvenile bunion. The pathologic findings associated with this deformity include a

Explanation

DISCUSSION
The radiographs show a hallux valgus deformity with a laterally deviated distal metatarsal articular surface, a large intermetatarsal angle with medial deviation at the first metatarsocuneiform joint, an elongated medial collateral ligament, and a contracted lateral collateral ligament. There is no distal 1-2 transverse intermetatarsal ligament. The distal transverse ligament in the first interspace extends from the second metatarsal to the lateral (fibular) sesamoid, remains intact, and keeps the sesamoids in a lateral position as the first metatarsal head migrates medially.
RECOMMENDED READINGS
Coughlin MJ. Roger A. Mann Award. Juvenile hallux valgus: etiology and treatment. Foot Ankle Int. 1995 Nov;16(11):682-97. PubMed PMID: 8589807.
View Abstract at PubMed
Coughlin MJ, Mann RA. Hallux valgus. In: Coughlin MJ, Mann RA, Saltzman CL, eds. Surgery of the Foot and Ankle. 8th ed. Philadelphia, PA: Mosby Elsevier; 2007:183-226.

Question 61

A 45-year-old man reports severe discomfort following a twisting injury to his right ankle and foot. Plain radiographs are negative; however, the CT scans shown in Figures 39a and 39b reveal a fracture. Management should consist of

Explanation

DISCUSSION: The CT scans show a fracture of the anterior process of the calcaneus that involves less than 25% of the joint surface with minimal to no displacement. The preferred treatment is external immobilization in either a walking cast or, more typically, a removable cast boot. For larger fractures that involve more than 25% of the articular surface with joint incongruity, open reduction and internal fixation may be indicated. Primary calcaneocuboid joint arthrodesis is not warranted because symptoms are rare in most patients. Delayed excision of the fragment is a late reconstructive option if painful nonunion develops. Percutaneous pin fixation is not indicated beceause there tends to be inherent stability in this fracture.
REFERENCES: Heckman JD: Fractures and dislocations in the foot, in Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD (eds): Rockwood and Green’s Fractures in Adults, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, pp 2267-2405.
Juliano TJ, Myerson MS: Fractures of the hindfoot, in Myerson MS (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 1297-1340.

Question 62

An eversion mechanism of injury is associated with which of the following ankle conditions?

Explanation

DISCUSSION: A fracture of the anterior colliculus is typically the result of an eversion mechanism resulting in a bony avulsion of the deltoid ligament from the anterior colliculus of the medial malleolus. An inversion ankle injury typically involves ligamentous damage to the lateral ligaments of the ankle to include the anterior talofibular ligament and calcaneofibular ligament. Acute and particularly chronic ankle sprains also can have associated injuries. The inversion mechanism has been implicated in osteochondral and transchondral talar dome lesions, producing splits in the peroneus tendons, and in the development of meniscoid and soft-tissue impingement lesions in the anterolateral ankle. An inversion mechanism can also stretch the superficial peroneal nerve, leading to pain and paresthesias along its distribution.
REFERENCES: Casillas MM: Ligament injuries of the foot and ankle in the athlete, in DeLee JC, Drez D, Miller MD (eds): Orthopaedic Sports Medicine: Principles and Practice, ed 2. Philadelphia, PA, WB Saunders, 2003, pp 2323-2357.
Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 233-245.

Question 63

Figures 1a and 1b show the clinical photograph and oblique radiograph of a 52-year-old man who has plantar first metatarsal pain. A felt pad in the shoe proximal to the area of pain has failed to provide relief. Management should now consist of

Explanation

DISCUSSION: The patient has a discrete callus that overlies a prominent medial sesamoid. Calluses typically occur in response to increased pressure on the skin. Initial treatment should be directed at reducing local pressure with a felt pad. Sesamoid shaving is indicated if the felt pad fails to provide relief. Sesamoidectomy should be reserved for refractory callus given the potential complications of transfer metatarsalgia or callus and hallux valgus. A first metatarsal dorsiflexion osteotomy is more appropriate for a diffuse callus that fails to respond to nonsurgical management. Cryoablation and topical salicylic acid are appropriate for plantar warts, which have a rougher appearance with multiple, small black spots in the lesion.
REFERENCES: Mann RA, Wapner KL: Tibial sesamoid shaving for treatment of intractable plantar keratosis. Foot Ankle 1992;13:196-198.
Mann RA, Mann JA: Keratotic disorders of the plantar skin. Instr Course Lect 2004;53:287-302.

Question 64

Figure 6 shows an object being held in an outstretched hand. To offset the moment created by the object (ignoring the weight of the forearm), the biceps must generate a force of

Explanation

DISCUSSION: Answering this question requires understanding of two important biomechanics concepts. First, because neither the object being held in the hand nor the body is moving and, hence, their accelerations are zero, the problem is one of static equilibrium in which the sum of the moments acting on the body is zero. Second, a moment is the action of a force that causes an object to rotate about any point away from its line of action. The magnitude of the moment is the magnitude of the force multiplied by the perpendicular distance between the line of action and the point (often called the moment arm or lever arm). In this problem, two forces are causing moments about the elbow. The magnitude of the moment caused by the object in the hand is 5 N times 30 cm or 150 N-cm. To maintain equilibrium, the moment caused by the biceps force must also have a magnitude of 150 N-cm. Its moment arm is 2 cm, so the magnitude of the biceps force is 150 N-cm divided by 2 cm, which equals 75 N. In general, functional loads such as the object are always at a mechanical advantage (ie, have a longer moment arm) over the muscle. Therefore, muscles must generate large forces to overcome the moments caused by even small functional loads.
REFERENCES: An KN, Chao ES, Kaufman KR: Analysis of muscle and joint loads, in Mow VC, Hayes WC (eds): Basic Orthopaedic Biomechanics, ed 2. New York, NY, Lippincott-Raven, 1997, pp 1-14.
Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 134-143.

Question 65

Figure 45 shows the current radiograph of an 11-year-old girl who sustained a simple nondisplaced fracture of the distal radius 4 weeks ago. Management at the time of injury consisted of application of a short arm cast but no manipulation. What is the major concern at this time?

Explanation

DISCUSSION: The fracture pattern represents a Peterson type I physeal injury, which is a comminuted metaphyseal fracture in which the fracture lines extend up to the physis. Because there is no displacement of the physis and the fracture lines do not cross the physis, there may be a tendency to dismiss this injury as a simple metaphyseal fracture with no significant sequelae. A small percentage of patients (3% in Peterson’s series) experience growth arrest. In this patient, a disabling ulnar plus deformity, defined as increased ulnar length in relationship to the distal radius, developed.
REFERENCES: Peterson HA: Physeal fractures: Part 2. Two previously unclassified types. J Pediatr Orthop 1994;14:431-438.
Peterson HA: Physeal and apophyseal injuries, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 108-109.

Question 66

A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Explanation

The patient’s curve is beyond the limit for bracing to be effective (40 degrees). Therefore, surgical treatment should be utilized. King type II curves (predominant thoracic curve with secondary lumbar curve) historically has used selective posterior thoracic fusion with segmental hook systems and rotation maneuvers to correct the thoracic curve and compensatory lumbar curve. The patient’s primary curve is thoracic and lumbar fusion would be contraindicated.

Question 67

A 7-year-old boy presents to the ED with visible right elbow deformity after a fall on the playground. His injury films are shown in figures A and B. The injury is closed, and there is a palpable radial pulse with a well-perfused hand. He undergoes multiple attempts at closed reduction and percutaneous pinning with 3 lateral pins in the operating room. Final radiographs show some gapping at the fracture site. At the end of the case, the radial pulse is no longer palpable and the hand appears pale. What is the next best step in management? Review Topic

Explanation

The patient has a type III supracondylar humerus fracture that lost a palpable radial pulse after closed reduction. Due to continued gapping at the fracture site, the next best step is to remove the pins, displace the fracture, and reassess perfusion as the brachial artery was likely interposed in the fracture site during the reduction maneuver.
The management of supracondylar humerus fractures is dictated significantly by the neurovascular examination. Loss of pulse and a pale, cool hand warrants emergent closed reduction and percutaneous pinning. If the vascular status does not change, open exploration is warranted. When a hand becomes pulseless and cool after reduction, it is typically due to the brachial artery being interposed in the fracture site. Undoing the reduction can often help. If there is still evidence of vascular compromise, open exploration is warranted. A pale (poorly perfused) hand or any change in neurovascular status requires urgent intervention. A pink, pulseless but well perfused hand can be observed.
Carter et al. surveyed over 300 pediatric orthopaedic surgeons on the management of type III supracondylar humerus fractures. They found an increasing trend toward lateral pin configuration and non-emergent delayed treatment.
Abzug et al. reviewed current concepts regarding management of supracondylar humerus fractures. They report an increased trend in surgical management of type II supracondylar humerus fractures. For the pink pulseless hand, they recommend admission for observation and splinting in 45 degrees of flexion.
Babal et al. reviewed nerve injuries in pediatric supracondylar humerus fractures. Anterior interosseous nerve palsy ranks highest, with ulnar nerve palsy highest with flexion type injuries. Medial pinning leads to risk of iatrogenic ulnar nerve injury.
Figures A and B are AP and lateral elbow radiographs showing a Gartland type III supracondylar humerus fracture.
Incorrect Answers:

Question 68

During the revision surgical procedure, thoracic pedicle screws are placed. Following placement, triggered electromyography (EMG) is performed by stimulating the pedicle screw heads. During testing the right T2 pedicle screw head returns a threshold of 2 mA. What does this reading indicate?

Explanation

DISCUSSION
This patient has developed a proximal junctional kyphosis following a long posterior fusion performed for treatment of degenerative lumbar scoliosis. Risk factors for proximal junctional kyphosis in the setting of instrumented fusions performed for degenerative scoliosis include advanced age, 360-
degree fusions, extension of fusion constructs to the sacrum, and upper instrumented vertebrae at the level of T1-3. The patient's junctional kyphosis is attributable to failure of the disk and ligamentous structures at T2-3 and would be graded as type I using the classification system of Yagi and associates. Most symptomatic proximal junctional kyphoses are treated with posterior extension of the fusion construct to a more proximal level spanning the kyphosed region. The use of orthoses or simple removal of instrumentation is unlikely to substantively impact symptoms or address the proximal kyphosis. Diabetes and obesity are known factors that increase risk for postsurgical infection following a spine fusion procedure. The most frequent complication following revision surgery for proximal junctional kyphosis, however, is the need for further surgery. In the study by Yagi and associates, 48% of patients who underwent revision surgery for proximal kyphosis developed further adjacent segment degeneration. In the proximal thoracic spine, where the pedicle may be narrow, triggered EMG testing of inserted pedicle screws may be used to assess for violation of the pedicle wall during insertion. In the setting of triggered EMG, thresholds exceeding 10 mA indicate a well-placed pedicle screw. Thresholds lower than 4 mA to 6 mA indicate that a screw is directly contacting a neural structure. Thresholds between 9 mA and 10 mA suggest that a breach of the pedicle may be present, but the screw is not contacting a neural structure.
RECOMMENDED READINGS
Yagi M, Rahm M, Gaines R, Maziad A, Ross T, Kim HJ, Kebaish K, Boachie-Adjei O; Complex Spine Study Group. Characterization and surgical outcomes of proximal junctional failure in surgically treated patients with adult spinal deformity.Spine (Phila Pa 1976). 2014 May 1;39(10):E607-14. doi: 10.1097/BRS.0000000000000266. PubMed PMID: 24525992. View
Abstract at PubMed
Cammarata M, Aubin CÉ, Wang X, Mac-Thiong JM. Biomechanical risk factors for proximal junctional kyphosis: a detailed numerical analysis of surgical instrumentation variables. Spine (Phila Pa 1976). 2014 Apr 15;39(8):E500-7. doi: 10.1097/BRS.0000000000000222. PubMed
PMID: 24480964. View Abstract at PubMed
Kim HJ, Lenke LG, Shaffrey CI, Van Alstyne EM, Skelly AC. Proximal junctional kyphosis as a distinct form of adjacent segment pathology after spinal deformity surgery: a systematic review. Spine (Phila Pa 1976). 2012 Oct 15;37(22 Suppl):S144-64. doi: 10.1097/BRS.0b013e31826d611b. PubMed PMID: 22885829. View Abstract at PubMed Schoenfeld AJ, Carey PA, Cleveland AW 3rd, Bader JO, Bono CM. Patient factors, comorbidities, and surgical characteristics that increase mortality and complication risk after spinal arthrodesis: a prognostic study based on 5,887 patients. Spine J. 2013 Oct;13(10):1171-9. doi: 10.1016/j.spinee.2013.02.071. Epub 2013 Apr 9. PubMed PMID:

Question 69

When planning a research study, the power of the study may be increased by

Explanation

The power of a study refers to the researchers' ability to detect a true association when one exists. Power is defined as 1-beta, with beta being the probability of concluding an association does not exist when one actually does (type II error). Increasing the sample size will increase the power of a study. A power analysis can be performed for both retrospective and prospective studies and is independent of the sample population used.

Question 70

A 55-year-old woman develops posttraumatic arthritis in the elbow following a distal humerus fracture. What is the most likely mid-term (5-10 years after surgery) complication following semiconstrained total elbow arthroplasty (TEA)?

Explanation

TEA has been described for posttraumatic arthritis of the elbow and typically involves a young patient population with multiple previous operations on the affected elbow. Morrey and Schneeberger found aseptic component loosening to be uncommon (<10% of patients) and usually occurring >10 years after surgery. Prosthetic fracture, usually of the ulnar component, is also a late-term finding. Infection is the most common mode of early failure but usually occurs within the first 5 years and has an overall rate of approximately 5%. Bushing wear has been reported as the most common cause of mechanical TEA failure in this population at
intermediate-term follow-up.

Question 71

A polytrauma patient underwent the following procedures: (1) statically locked intramedullary nailing for a right femoral shaft fracture; (2) open reduction with plate-and-screw fixation [ORIF] for a right simple distal fibula fracture; (3) ORIF right middle third radius and ulna fracture; and (4) ORIF left humeral shaft fracture. What is the appropriate weightbearing status for this patient? Review Topic

Explanation

The standard postoperative weightbearing for locked medullary nailing for femoral shaft fractures and humeral shaft fractures is weight bearing as tolerated (WBAT). Simple ORIF ankle fractures may be managed with early protected weight bearing. ORIF right middle third radius and ulna fracture should be managed with a period of non-weight bearing due to risk of secondary displacement of the fracture.
Tingstad et al. examined the effect of immediate weightbearing on plated fractures of the humeral shaft. They reported that immediate weightbearing on humeral shaft fractures, treated with plating and full weightbearing, did not have any negative effect on the union or malunion rates.
Brumback et al. evaluated the feasibility, safety and efficacy of immediate weightbearing after treatment of femoral shaft fractures with statically locked IM nail. Using biomechanical and clinical data, they showed that all fractures united with no loss of fixation or hardware failure.
Starkweather et al. retrospectively assessed the complications and loss of reduction in patients who bore weight in a short leg cast within 15 days after surgical repair of acute unilateral closed ankle fractures. Of the 81 ankle fracture radiographs, 80 (98.8%) showed no displacement in fracture reduction on the final follow-up examination. These results suggest early protected weightbearing may be safe.
Incorrect Answers:

Question 72

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 73

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

Explanation

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

Question 74

A 71-year-old woman undergoes a posterior lumbar decompression and fusion from L4-S1. Thirty-six hours after the procedure, she reports severe right-sided chest pain and shortness of breath. Doppler ultrasound reveals a clot proximal to the knee within the femoral vein. A large pulmonary embolus is confirmed by CT angiography. The next most appropriate step in management should consist of

Explanation

DISCUSSION: In a review of 13,000 spinal procedures, nine patients were treated with heparin following development of pulmonary emboli. Of these patients, six had serious complications ranging from wound drainage to paralysis. Heparin therapy instituted within 10 days of the surgical procedure resulted in a 100% complication rate. Vena cava filter placement has a complication rate of 0.12% to 10.1%. Removable filters are currently in clinical trials.
REFERENCES: Cain JE Jr, Major MR, Lauerman WC, et al: The morbidity of heparin therapy after development of pulmonary embolus in patients undergoing thoracolumbar or lumbar spinal fusion. Spine 1995;20:1600-1603.
Roberts AC: Venous imaging and inferior vena cava filters. Curr Opin Radiol 1992;4:88-96.
Becker DM, Philbrick JT, Selby JB: Inferior vena cava filters. Arch Intern Med
1992;152:1985-1994.

Question 75

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

Explanation

DISCUSSION: Surgical margins are classified according to the plane of dissection in relation to the tumor. An intralesional procedure is where the plane of dissection passes through the tumor. A marginal resection involves a resection where the plane of dissection is through the reactive zone of the tumor. A wide resection is through completely normal tissue outside of the reactive zone. A radical resection removes all of the muscles and/or bone of the compartment that are involved by the tumor.
REFERENCE: Enneking WF, Spanier SS, Goodman MA: A system for the surgical staging of musculoskeletal sarcoma. Clin Orthop 1980;153:106-120.

Question 76

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Explanation

DISCUSSION: Etanercept is a molecule consisting of the Fc portion of IgG fused to the extracellular domain of the p76 human THF-α receptor. It is soluble and binds TNF-α. Infliximab is the monoclonal antibody that binds TNF-α. IL-1 receptor antagonists are still in development. Leflunomide is a drug that inhibits pyrimidine synthesis and is similar to methotrexate as an antimetabolite.
REFERENCE: Koval KJ (ed): Orthopaedic Knowlegde Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 193-199.

Question 77

A pediatric orthopaedic surgeon refers a child to a neurologist. The neurologist’s office requests the office records of the pediatric orthopaedic surgeon. To maintain Health Insurance Portability and Accountability Act (HIPAA) compliance, what must the surgeon obtain from the parent(s) prior to sending records?

Explanation

The privacy rules do not require an individual’s written authorization for certain permitted or required uses and disclosures of the medical records. Patient or parental authorization is not required for disclosures for certain purposes related to treatment, payment, or health care operations. Specifically, HIPAA does not require a covered entity to obtain patient authorization for many of the health care industry’s most fundamental activities such as providing care.

Question 78

A 6-year-old girl has never been able to crawl or walk and can sit only when propped. History reveals no complications during pregnancy or delivery. Examination reveals a 30-degree scoliosis from T4 to L3. Deep tendon reflexes are absent, but fasciculations are present. The most likely genetic defect is the result of an abnormality in

Explanation

DISCUSSION: The patient’s findings are consistent with an intermediate form of spinal muscular atrophy. Children with this condition appear normal at birth but are not able to walk. The disorder affects anterior horn cells. Fasciculations may be present, but deep tendon reflexes are typically absent. The development of scoliosis is almost universal with this type of spinal muscular atrophy. More than 90% of patients with spinal muscular atrophy have deletions in the telomeric survival motor neuron gene. Peripheral myelin protein 22 is abnormal in Charcot-Marie-Tooth type IA. Connexin 32 is abnormal in the X-linked type of Charcot-Marie-Tooth disease. Neurofibromin is affected in neurofibromatosis type 1. Friedreich’s ataxia is secondary to a disorder of frataxin.
REFERENCES: Buckwalter JA, Einhorn TA, Simon SR (eds): Orthopaedic Basic Science, ed 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 111-131.
Thompson GH, Berenson FR: Other neuromuscular disorders, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 633-676.

Question 79

A 68-year-old woman has been progressing slowly after undergoing humeral head replacement for a four-part fracture 3 months ago. She has not regained active elevation, she feels an audible clunk on attempting elevation, and she reports pain and weakness. She used a sling for 2 weeks in the immediate postoperative period. Radiographs are shown in Figure 37a through 37c. Management should consist of

Explanation

DISCUSSION: Immediate repair of the tuberosity and rotator cuff is recommended on identifying the avulsion or nonunion. Revising the humeral component to increase tension and length will overtighten the cuff and increase the chance of tuberosity pull-off. The glenoid is uninvolved and should not be replaced. Attempts to strengthen the rotator cuff will be unsuccessful because the insertions are no longer attached to the humerus when the tuberosities avulse.
REFERENCES: Brown TD, Bigliani LU: Complications with humeral head replacement. Orthop Clin North Am 2000;31:77-90.
Muldoon MP, Cofield RH: Complications of humeral head replacement for proximal humeral fractures. Instr Course Lect 1997;46:15-24.

Question 80

Figure 13 is the photograph of 18-month-old triplets with a lower-limb condition. What is the best initial treatment? Review Topic

Explanation

Brodie's Abscess
Osteomyelitis of the humeral metaphysis
Subperiosteal abscess of the humerus
Presence of subcutaneous air
High risk of proximal humeral growth arrest
This patient has osteomyelitis of the humerus with a large subperiosteal abscess. The presence of subperiosteal abscess necessitates surgical intervention for irrigation and debridement (I&D).
The diagnosis of acute osteomyelitis in children is made based upon a constellation of findings including pain, systemic signs of infection, elevated serum inflammatory markers, and imaging studies demonstrative of osseous infection. It is most commonly hematogenously spread to the metaphysis of immature bone, which is highly vascular prior to skeletal maturity. Treatment involves obtaining specimen for culture, empiric antibiotic treatment, and surgical irrigation and debridement of known abscesses. The end-point of treatment is return of pain-free functionality and the resolution of local/systemic signs of infection.
Conrad reviewed the management of acute hematogenous osteomyelitis and emphasized that surgical intervention in the presence of abscess can be both therapeutic and diagnostic: I&D can obtain culture and narrow the antibiotic plan.
Jones et. al. reviewed chronic pediatric osteomyelitis and report that surgery is the mainstay of treatment because removal of dead bone is essential for resolution of infection. This may be performed with sequestrectomy and curettage, with an emphasis on prevention of pathologic fracture, growth disturbances, bone loss, joint involvement, and permanent loss of function.
Figure A is a coronal STIR MRI image of the humerus demonstrating osteomyelitis
with extensive subperiosteal abscess.
Incorrect Answers:
Brodie's abscess is a type of subacute osteomyelitis which remains indolent and creates a focal intra-osseous abscess. This is not demonstrated in the clinical image.
The patient does have osteomyelitis of the humeral metaphysis, but this alone is not the indication for surgery. Uncomplicated osteomyelitis may be treated effectively with antibiotics alone.
Presence of subcutaneous air is suggestive of necrotizing fasciitis, which is a surgical emergency. The MRI however does not demonstrate this finding.
The infection and its surgical management both increase risk of injury to the proximal humeral physis and has the potential for growth arrest or angular deformity.
(SBQ13PE.3) Figure A demonstrates a physical examination maneuver in a 1 month old infant. What is this maneuver? Review Topic

Ortolani Test
Barlow Test
Galeazzi Sign
Patrick test
Teratologic Sign
Figure A shows a schematic image of the Ortalani test.
The Ortolani test, or Ortolani maneuver, is part of the physical examination for developmental dysplasia of the hip. It is used alongside the Barlow test to detect subluxated hips that are either reducible or irreducible. A positive sign is a distinctive 'clunk' which can be heard and felt as the femoral head relocates anteriorly into the acetabulum.
Guille et al. showed that the use of Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step before they are able to stand.
Video V is a lecture discussing the hip examination of the infant. Incorrect Answers:
pressure on the knee, directing the force the femoral head posteriorly. A positive Barlow test would result in posterior subluxation/dislocation of the hip. Answer 3: Galeazzi test is performed by flexing an infant's knees in the supine position so that the ankles touch the buttocks. If the knees are not level then the test is positive, which indicates a potential congenital hip issue (e.g. DDH). Answer 4: Patrick or Faber test (flexion, abduction, external rotation) has been described both for stressing the SI joint and for isolating symptoms to the hip Answer 5: Teratologic dislocation of the hip is a term used to imply that the hip joint did not develop normally in utero, thus the hip is in a fixed dislocated position at birth.

Question 81

A 51-year-old plumber has a failed peroneus brevis tendon repair. He reports continued pain and swelling in the distal retrofibular area. MRI shows longitudinal tears of the peroneus longus and peroneus brevis. What is the surgical treatment of choice at this time?

Explanation

DISCUSSION: A flexor digitorum longus transfer, while not as strong as the peroneals, improves the tendon balance and maintains hindfoot mobility. Subtalar fusion is a salvage procedure. Posterior tibial tendon transfer compromises inversion strength and arch height. Functional absence of the peroneals results in an imbalance that could lead to forefoot varus.
REFERENCES: Redfern D, Myerson M: The management of concomitant tears of the peroneus longus and brevis tendons. Foot Ankle Int 2004;25:695-707.
Borton DC, Lucas P, Jomha NM, et al: Operative reconstruction after transverse rupture of the tendons of both peroneus longus and brevis: Surgical reconstruction by transfer of the flexor digitorum longus tendon. J Bone Joint Surg Br 1998;80:781-784.

Question 82

A 62-year-old man who underwent total knee arthroplasty 6 months ago now reports pain after falling on the anterior portion of the knee. Examination reveals weakness of knee extension but no extensor lag. Flexion that had once measured 115 degrees is now limited to 70 degrees because of pain. A radiograph is shown in Figure 25. Management should now consist of

Explanation

DISCUSSION: The patient has a type IIIB patellar fracture (inferior pole fracture with an intact patellar tendon). Nonsurgical management is the treatment of choice if there is little displacement and the extensor mechanism is intact.
REFERENCES: Brown TE, Diduch DR: Fractures of the patella, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 3. Philadelphia, PA, Churchill Livingstone, 2001, vol 2, pp 1290-1312.
Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000,

pp 323-337.

Question 83

A skeletally mature GMFCS V child with spastic quadriplegic cerebral palsy presents with progressive scoliosis and inability to sit upright in a wheelchair. Radiographs are shown in Figures A and B, depicting a long C-shaped 75 degree curve with pelvic obliquity. Which is the most appropriate treatment option? Review Topic

Explanation

She requires surgical decompression to prevent progressive neurologic deterioration
85% of individuals over the age of 60 years of age demonstrate these findings
She is indicated for MRI to rule out cervical radiculopathy
She would benefit from modalities such as heat, cold, and transcutaneous electrical stimulation
She has <10% chance of having symptomatic improvement with non-operative treatment
The patient has symptomatic cervical spondylosis. She should be told that 85% of asymptomatic individuals over the age of 60 demonstrate these radiographic findings.
Cervical spondylosis is defined as age-related degenerative changes within the cervical spinal column. It can present as axial neck pain, cervical radiculopathy, cervical myelopathy, or as a combination of each. Radiographs demonstrate loss of disc height, arthrosis of the facet and uncovertebral joints, and endplate sclerosis. Imaging such as cervical spine radiographs and MRI should be interpreted carefully and correlated with clinical symptoms, as radiographic evidence of spondylosis is frequently seen in asymptomatic patients.
Boden et. al. reviewed the cervical MRI of 63 asymptomatic volunteers with no history of cervical spine symptoms. Of those, 19% were interpreted as having an abnormality. These findings included herniated nucleus pulposus, bulging disc, and foraminal stenosis. 60% of patients over 40 years demonstrated disc degeneration or narrowing at one level.
Rao et al. reviewed the presentation, pathogenesis, and management of cervical spondylosis. In this review, they report that 85% of patients older than 60 years demonstrate cervical spondylosis on radiography.
Figure A is a lateral cervical spine radiograph demonstrating spondylosis at multiple levels. There is disc height loss, facet sclerosis, and anterior osteophyte formation.
Incorrect Answers:

Question 84

What molecules have been shown to promote fibrosis during muscle injury?

Explanation

A muscle's response to injury can be divided into 4 phases: necrosis, inflammation, repair, and fibrosis. Necrosis involves the degeneration of the muscle fibrils and death. The inflammatory cells then phagocytose the debris and secrete cytokines that promote vascularity. Muscle regeneration does not occur until phagocytic cells remove the debris. Consequently, anti-inflammatory drugs may have negative effects on muscle healing by inhibiting macrophage-induced phagocytosis. Muscle fibrosis occurs at the same time as muscle regeneration and has been shown to involve TGF-ß1. IGF-1 and bFGF are important trophic factors in muscle regeneration. Bone morphogenetic protein has several functions including bone and cartilage regeneration.

Question 85

Which of the following factors increases the risk of sciatic nerve injury in primary total hip arthroplasty (THA)?

Explanation

DISCUSSION: Injury to the sciatic nerve is a relatively rare but serious complication of THA. Dissection of the sciatic nerve is not typically done during primary THA, although the nerve can be identified during the surgical approach. An anterolateral approach to THA would not necessarily be associated with any greater incidence of sciatic nerve injury than other approaches. Screw fixation for the acetabular component is often a matter of surgeon preference. Provided that the anatomic safe zones for screw fixation (posterior inferior and posterior superior) are recognized, injury to the sciatic nerve from acetabular screws can be minimized. Restoration of anatomic length is important in primary THA. Overlengthening can result in sciatic nerve palsy. Developmental dysplasia of the hip can lead to a congenitally shortened extremity with concomitant congenital shortening of the associated neurovascular structures. Overlengthening of the extremity during THA for developmental dysplasia of the hip can lead to sciatic palsy. Osteonecrosis is not an associated risk factor for sciatic nerve palsy.
REFERENCES: DeHart MM, Riley LH Jr: Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg 1999;7:101-111.
Anas P, Felix B: Evaluation and prevention of postoperative complications, in Neurologic Injury in Revision THA. New York, NY, Springer Verlag, 1999, pp 361-371.

Question 86

What clinical scenario is most consistent with the MR image of the L4-L5 disk level shown in Figure 14? Review Topic

Explanation

The MRI scan reveals a foraminal disk herniation originating from the L4-L5 disk space that has migrated into the foramen compressing the left L4 nerve root. There is no evidence of compression of the right L5 nerve root. Bowel and bladder dysfunction are not associated with L4-mediated nerve function. There is no evidence of arachnoiditis or pseudomeningocele.

Question 87

Based on the findings seen at C5-6 in Figure 30, the most likely deficit for this patient will be weakness of the

Explanation

DISCUSSION: A herniated cervical disk at C5-6 causes a C6 radiculopathy. There are eight cervical nerve roots and seven cervical vertebrae, and C8 exits between the C7 and T1 vertebrae. The C6 nerve root typically innervates the biceps and wrist extensor. The deltoid is predominantly innervated by C5. The wrist flexor and triceps are predominantly innervated by C7. Grip strength is predominantly a function of C8.
REFERENCE: Hoppenfeld S: Evaluation of nerve root lesions involving the upper extremity, in Orthopaedic Neurology. Philadelphia, PA, JB Lippincott, 1977, pp 7-23.

Question 88

Figure 37 shows the clinical photograph of a 1-day-old infant who weighed 10.25 lb at birth. Examination reveals an absent right Moro reflex and limited active motion of the right shoulder, elbow, and wrist, but flexion of the fingers. Passive range of motion of the shoulder and elbow is normal. What is the most likely diagnosis?

Explanation

DISCUSSION: The patient’s right upper extremity is held in the “head waiter’s” posture with the shoulder internally rotated, the elbow extended, and the wrist in flexion. The Erb type of obstetrical brachial plexus palsy involves the C5 and C6 nerve root, and occasionally, as in this child, the C7 nerve root. Obstetrical palsy is a traction injury, and is associated with a high birth weight, shoulder dystocia, cephalopelvic disproportion, or the use of forceps. Erb palsy is four times more common than injury to the entire plexus or injury to the C8 and T1 nerve roots. It results from the shoulder being depressed while the head and neck are laterally rotated, extended, and tilted in the opposite direction. Most patients recover wrist extension and elbow flexion. Patients with residual weakness of shoulder external rotation and abduction will benefit from release of the pectoralis major, latissimus dorsi, and teres major, with transfer of the latissimus dorsi and the teres major to the posterosuperior aspect of the rotator cuff. Recent studies using arthrograms and CT scans have shown a higher incidence of posterior glenoid deficiency and posterior subluxation than that observed with plain radiographs. The posterior subluxation or dislocation can be effectively reduced by tendon release and transfer procedures.
REFERENCES: Hoffer MM, Phipps GJ: Closed reduction and tendon transfer for treatment of dislocation of the glenohumeral joint secondary to brachial plexus birth palsy. J Bone Joint Surg Am 1998;80:997-1001.
Pearl ML, Edgerton BW: Glenoid deformity secondary to brachial plexus birth palsy. J Bone Joint Surg Am 1998;80:659-667.
Waters PM, Smith GR, Jaramillo D: Glenohumeral deformity secondary to brachial plexus birth palsy. J Bone Joint Surg Am 1998;80:668-677.

Question 89

What is the average linear wear rate of a conventional, noncross-linked ultra-high molecular weight polyethylene liner used in total hip arthroplasty?

Explanation

DISCUSSION: Several studies have shown that ultra-high molecular weight polyethylene liners used in total hip arthroplasties wear at a rate of 0.1 to 0.2 mm/yr. The orthopaedic surgeon performing total hip arthroplasties should be aware of the average wear rate so that potential problems can be identified when following patients postoperatively.
REFERENCES: Callaghan JJ, Albright JC, Goetz DD, Olejniczak JP, Johnston RC: Charnley total hip arthroplasty with cement: Minimum twenty-five year follow-up. J Bone Joint Surg Am 2000;82:487-497.
Isaac GH, Wroblewski BM, Atkinson JR, Dowson D: A tribological study of retrieved hip prostheses. Clin Orthop 1992;276:115-125.

Question 90

Figure 48 shows the radiograph of a 17-year-old boy who sustained a gunshot wound to his forearm. There is a small entrance wound on the volar surface. The exit wound is dorsal and more than 15 cm in size, with loss of skin and an extensive amount of devitalized muscle hanging out of the wound. Vascular supply to the hand is excellent, the ulnar and median nerves are intact in the hand, but the radial sensory nerve function is absent. After repeated surgical debridements of the wound and bone, definitive treatment for the fracture would most likely be which of the following? Review Topic

Explanation

The injury needs a very complex traumatic reconstruction. After repeat debridements, there will be a very long segmental loss of the radius, with a significant loss of skin and muscle covering the bone. Spanning external fixation represents a good temporary fixation tool but will not be a definitive solution. The preferred procedure is a vascularized fibular graft with associated skin flap from the lateral leg. This surgical option brings healthy vascularized bone and soft-tissue coverage into an area with significant bone and soft-tissue loss. Placement of large quantities of allograft material, especially strut allograft, is generally contraindicated in the setting of open fractures with soft-tissue compromise because of the risk of infection. Internal fixation and massive cancellous autografting is usually limited to one defect of less than 5 cm with intact soft-tissue covering.

Question 91

No fractures were identified and the patient was treated nonsurgically in a range-of-motion brace. Two months later, he continued to experience elbow pain and was unable to return to sports. He regained motion and strength with physical therapy, there was no gross instability with varus or valgus testing, and he had a negative moving-valgus stress test. The orthopaedic surgeon performed an examination under anesthesia in the operating room (Video 54). Which anatomic structure is injured?

Explanation

DISCUSSION
Ninety percent of elbow dislocations occur in a posterolateral direction. O’Driscoll and associates described the mechanism of injury in posterolateral elbow dislocations in 1992, reporting that they occur most typically after a fall onto an outstretched arm. As the arm hits the ground it causes axial compression, forearm supination, and valgus load across the elbow. The triceps fires, pulling the olecranon posterior; the forearm supinates while simultaneous shoulder internal rotators fire; and the elbow falls into valgus. These 3 mechanisms cause the elbow to subluxate and dislocate posterolaterally. The elbow is most stable following posterolateral dislocation in a flexed and pronated position. The elbow is least stable in extension and supination. Simple dislocation often can be treated nonsurgically, while fracture dislocation will usually necessitate surgical intervention. The video shows the elbow pivot-shift test, which evaluates for posterolateral rotatory instability. A positive test finding elicits apprehension and, in this case, radial head subluxation and confirms an insufficient lateral UCL.

Question 92

A 35-year-old woman who underwent open reduction and internal fixation of a calcaneal fracture 14 months ago reports pain that has failed to respond to nonsurgical management. Examination reveals limited painful subtalar motion but no hindfoot deformity. A lateral radiograph is shown in Figure 6. Surgical reconstruction is best accomplished with

Explanation

DISCUSSION: The patient has posttraumatic subtalar joint arthrosis that developed following a calcaneal fracture. Because there is no hindfoot deformity, in situ subtalar joint arthrodesis is the treatment of choice. Calcaneal osteotomy or distraction bone block arthrodesis is beneficial in patients with severe talar dorsiflexion or malunion of the calcaneal body. Triple arthrodesis is not warranted without changes at the transverse tarsal joint, and typically even with injury into the calcaneocuboid joint, this joint is often asymptomatic. Pantalar arthrodesis is not indicated as the pathology is occurring at the subtalar joint and not in the ankle joint.
REFERENCES: Sanders R: Fractures and fracture-dislocations of the calcaneus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999,

pp 1422-1464.
Juliano TJ, Myerson MS: Fractures of the hindfoot, in Myerson MS (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 1297-1340.
Chandler JT, Bonar SK, Anderson RB, Davis WH: Results of in situ subtalar arthrodesis for late sequelae of calcaneus fractures. Foot Ankle Int 1999;20:18-24.

Question 93

A 6-year-old girl is referred for the elbow injury seen in Figure 2. What is the most appropriate treatment?

Explanation

DISCUSSION: The patient has a displaced lateral condyle fracture; therefore, simple immobilization for 3 to 8 weeks is likely to result in malunion or nonunion. Closed reduction of such injuries is rarely successful. The fracture is unstable, so fixation is required after open reduction. Because the fixation must cross the physis, smooth pins are indicated for the skeletally immature elbow. Open reduction with fixation has been shown to reduce the risk of delayed union and malunion.
REFERENCES: Beaty JH, Kasser JR: The elbow: Physeal fractures, apophyseal injuries

of the distal humerus, avascular necrosis of the trochlea, and T-condylar fractures, in Beaty JH, Kasser JR (eds): Fractures in Children, ed 5. Philadelphia, PA, Lippincott Williams & Wilkins, 2001, pp 625-703.
Rutherford A: Fractures of the lateral humeral condyle in children. J Bone Joint Surg Am 1985;67:851-856.
Hasler CC, von Laer L: Prevention of growth disturbances after fractures of the lateral humeral condyle in children. J Pediatr Orthop B 2001;10:123-130.

Question 94

Figure 6 shows the lateral radiograph of a 22-year-old woman who has painful Scheuermanns’s kyphosis in the middle and lower thoracic spine. When planning surgical correction using instrumentation, the distal aspect of the instrumentation should ideally extend to the

Explanation

DISCUSSION: Posterior constructs for Scheuermann’s kyphosis ideally should extend from the most superior to the most inferior aspect of the Cobb angulation. However, the most distal fusion level must be in a stable or lordotic position to avoid the development of junctional kyphosis. Lowe reported that failure to incorporate the first lordotic segment of the lumbar spine is associated with a higher risk of junctional kyphosis. The first lordotic segment of the lumbar spine is typically at least one level below the distal aspect of the curve as measured by the Cobb technique and most commonly is in the upper part of the lumbar spine.
REFERENCES: Lowe TG: Scheuermann’s disease. Orthop Clin North Am 1999;30:475-487.
Lenke LG: Kyphosis of the thoracic and thoracolumbar spine in the pediatric patients: Prevention and treatment of surgical complications. Instr Course Lect 2004;53:501-510.

Question 95

The radiographic finding in Figure 58 is indicative of what type of acetabular fracture?

Explanation

Bilateral open reduction and internal fixation
Open reduction internal fixation on the right, reamed intramedullary nailing on the left
Temporizing external fixation on the right, open reduction and internal fixation on the left
Bilateral reamed intramedullary nailing
Bilateral temporizing external fixation
This patient presents with features of hemodynamic instability and a high injury severity score. The next most appropriate treatment would be temporizing external fixation bilaterally. This patient meets the criteria for damage control orthopaedics.
Damage control orthopaedics is an approach that contains and stabilizes orthopaedic injuries so that the patient's overall physiology does not undergo further inflammatory insult. As a result, external fixation of femoral shaft fracture and pelvic stabilization is an effective treatment under this strategy. Other indications include vascular injury and severe open fracture.
Pallister et al. reviewed the effects of surgical fracture fixation on the systemic inflammatory response to major trauma. They show that early stabilization of major long bone fractures is beneficial in reducing the incidence of acute respiratory distress syndrome and multiple organ failure. However, early fracture surgery increases the post-traumatic inflammatory response, which carries a higher complication rate compared to temporary fixation.
Tisherman et al. created clinical guidelines for the endpoints of resuscitation. Level I data found that standard hemodynamic parameters do not adequately quantify the degree of physiologic derangement in trauma patients. The initial base deficit, lactate level, or gastric pH should be used to stratify patients with regard to the need for ongoing fluid resuscitation.
Pape et al. retrospectively reviewed the impact of early total care vs. damage control orthopaedics in the treatment of femoral shaft fractures in polytrauma patients. They found a significantly higher incidence of acute respiratory distress syndrome (ARDS) with intramedullary nailing (15.1%) compared to external fixation (9.1%) when DCO subgroups were compared.
Figure A is a pelvic AP radiograph showing a right hip fracture-dislocation with an ipsilateral femoral shaft fracture. On the left side there is a displaced pertrochanteric hip fracture.
Incorrect Answers:

Question 96

Demyelination diseases as multiple sclerosis and Guillain-Barre $ create neurologic symptoms by

Explanation

These diseases cause demyelinated regions of the axon and thus have a higher capacitance and lower membrane resistance (opposite of normal) and thus affects an action potential’s saltatory propagation. When an action potential is propagate down a myelinated axon and reaches a demyelinated region its conduction becomes slowed or may even stop. This loss of conduction had effects on behavior.

Question 97

A full-term newborn has webbing at the knees, rigid clubfeet, a Buddha-like posture of the lower extremities, and no voluntary or involuntary muscle action at and below the knees. Radiographs of the spine and pelvis reveal an absence of the lumbar spine and sacrum. What maternal condition is associated with this diagnosis?

Explanation

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.

J Perinatol 2002;22:171-174.

Question 98

A 67-year-old female presents with shoulder pain for 3 months after falling down stairs. Imaging demonstrates a large rotator cuff tear involving multiple tendons. You perform an arthroscopic rotator cuff repair and biceps tenodesis. At her 2 month follow up, she reports worsening shoulder pain and decreased range of motion. Examination reveals active forward flexion to 80°. Passive range of motion is full. There is a positive external rotation lag sign. An MRI is performed and is pictured in Figure A. Which is the best treatment for this patient? Review Topic

Explanation

The next best step for this patient's failed rotator cuff repair is a revision repair of the infraspinatus.
Failed rotator cuff repair is multifactorial. Structural failure of repair is the result of both intrinsic and extrinsic factors. Intrinsic factors include advancing patient age, increasing tear size, poor tendon and muscle quality, systemic disease and smoking history. Extrinsic factors include inadequate biomechanical construct or repair configuration and overaggressive postoperative rehabilitation.
Denard et al authored a review article on revision rotator cuff repair. Indications for revision repair are persistent symptoms despite nonoperative management in whom infection and advanced degenerative changes have been ruled out. Satisfactory results have been reported following revision repair of recurrent rotator cuff tears, particularly with arthroscopic techniques. Female sex and preoperative forward flexion < 135° is associated with poorer outcomes.
Lambers Heerspink et al found that increasing age, larger tear size and additional biceps or acromioclavicular (AC) joint procedures have a negative influence on cuff integrity at follow up. Smoking, duration of symptoms, obesity and medical comorbidities were not found to influence cuff integrity in this study. Only AC procedures and workers’ compensation status were associated with worse functional outcomes.
Figure A is a coronal T2 MRI demonstrating a failed rotator cuff repair with retear. Incorrect Responses:

Question 99

A 45-year-old woman awakens with the acute onset of burning left shoulder pain that radiates toward the axilla. She denies any history of trauma. On examination, she is unable to abduct her arm but has full passive shoulder motion. Her sensation is intact. Cervical spine examination reveals full range of motion and a negative Spurling’s test. Radiographs and MRI studies are normal for the cervical spine and shoulder. What is the most likely diagnosis?

Explanation

DISCUSSION: The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.
REFERENCES: Misamore GW, Lehman DE: Parsonage-Turner syndrome (acute brachial neuritis). J Bone Joint Surg Am 1996;78:1405-1408.
McCarty EC, Tsairis P, Warren RF: Brachial neuritis. Clin Orthop Relat Res 1999;368:37-43.

Question 100

A 25-year-old semiprofessional football player sustains a hyperextension injury to the left foot. He is unable to bear weight. Examination reveals tenderness along the midfoot with swelling and plantar ecchymosis. Radiographs are negative. What is the next step in evaluation of this patient?

Explanation

DISCUSSION: The patient has a suspected Lisfranc sprain based on the plantar ecchymosis. The first step in diagnosis is a dynamic radiographic study. This should include a physician-assisted midfoot stress examination or standing weight-bearing radiographs to evaluate for displacement. There is no evidence of compartment syndrome, and a bone scan, CT, and MRI are expensive tests that are not warranted.
REFERENCES: Early JS: Fractures and dislocations of the midfoot and forefoot, in Bucholz R, Heckman JD, Court-Brown CM (eds): Rockwood and Green’s Fractures in Adults. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp 2337-2400.
Hunt SA, Ropiak C, Tejwani NC: Lisfranc joint injuries: Diagnosis and treatment. Am J Orthop 2006;35:376-385.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

closed reduction and percutaneous screw placement.
open reduction internal fixation through an anterior midline approach.
spanning external fixation and closed manipulative realignment.
ring fixation.

Correct Answer: spanning external fixation and closed manipulative realignment.

Explanation:

Question 2:

Options:

Ceramic-on-ceramic
Ceramic-on-highly cross-linked polyethylene (HXPE)
Metal-on-HXPE
Metal-on-metal

Correct Answer: Metal-on-metal

Explanation:

Question 3:

Options:

mechanical alignment radiographs.
stress radiographs of the knee.
comparison radiographs of both knees.
an erythrocyte sedimentation rate and a C-reactive protein.
examination of the hip.

Correct Answer: examination of the hip.

Explanation:

DISCUSSION: While all of the answers may be appropriate, radiating pain from hip pathology must be excluded. At this age, a slipped capital femoral epiphysis is likely. Therefore, the hip must be examined.
REFERENCES: Kocher MS, Bishop JA, Weed B, et al: Delay in diagnosis of slipped capital femoral epiphysis. Pediatrics 2004;113:322-325.
Matava MJ, Patton CM, Luhmann S, et al: Knee pain as the initial symptom of slipped capital femoral epiphysis: An analysis of initial presentation and treatment. J Pediatr Orthop 1999;19:455-460.

Question 4:

In a patient with a major head injury and a femoral shaft fracture, intraoperative hypotension during femoral fixation has been associated with which of the following?

Options:

Increased time needed for rehabilitation
Increased pneumonia rate
Increased intensive care unit length of stay
Decreased discharge Glascow Coma Scale
Decreased hospital length of stay

Correct Answer: Increased time needed for rehabilitation

Explanation:

Question 5:

Options:

Valgus extension overload
Varus posteromedial rotatory instability (VPMRI)
Valgus posterolateral rotatory instability (VPLRI)
Olecranon bursitis The patient has valgus extension overload. This is a spectrum of pathologies, often seen in pitchers, that begins with posteromedial impingement between the medial olecranon and posterior trochlea during forceful elbow extension. As a result, a medial olecranon osteophyte is typically the first notable imaging finding. As pathology increases, there can be progressive damage to the medial collateral ligament (MCL), degeneration of the radiocapitellar articulation, and neuritis of the ulnar nerve. VPMRI is often associated with a large anteromedial coronoid fracture and posterior band MCL rupture. VPLRI occurs when the lateral collateral ligament complex is ruptured. Olecranon bursitis presents with focal swelling or a fluid collection over the posterior aspect of the olecranon.

Correct Answer: Valgus extension overload

Explanation:

Question 6:

Options:

Posterior atlantoaxial arthrodesis
Placement of a dens screw
Arthrodesis from the posterior occiput to C2
Continued nonsurgical management
Anterior cervical diskectomy and fusion at C2-3

Correct Answer: Posterior atlantoaxial arthrodesis

Explanation:

Question 7:

Options:

observation.
varus prevention orthoses.
physeal bar resection.
proximal tibial osteotomy that produces a neutral mechanical axis.
proximal tibial osteotomy that produces 10 degrees of valgus.

Correct Answer: proximal tibial osteotomy that produces 10 degrees of valgus.

Explanation:

Question 8:

Options:

a local steroid injection into the flexor hallucis longus tendon sheath.
range-of-motion exercises.
open reduction and internal fixation.
nonsteroidal anti-inflammatory drugs.
excision of the fragment.

Correct Answer: excision of the fragment.

Explanation:

Question 9:

By which mechanism can a true aneurysm of the ulnar artery result?

Options:

Blunt trauma
Stab wound
Gunshot wound
Arterial catheterization True aneurysms contain all arterial layers. As such, they occur following an arterial injury that allows the vessel to gradually dilate. A true aneurysm is more uniform in shape and is characterized by having an endothelial lining. True aneurysms result from repeated blunt trauma or vessel diseases that weaken the wall. A pseudoaneurysm, or false aneurysm, results from an arterial wall penetration. The extravasated hematoma subsequently organizes and then recanalizes. The lumen of this false aneurysm has no endothelial lining. Pseudoaneurysms result from penetrating injuries from external sources or from fractures.

Correct Answer: Blunt trauma

Explanation:

Figures 1 and 2 are the radiographs of a 17-year-old boy who injured his wrist 6 months ago. He is experiencing pain and limited motion. What is the most effective treatment option?

Question 10:

Options:

Sex of the patient
Type of health insurance
Child greater than 10 years of age
Acute knee injuries requiring operative treatment
Timing of the referral

Correct Answer: Sex of the patient

Explanation:

Question 11:

Options:

Cam-type femoroacetabular impingement
Pincer-type femoroacetabular impingement
Hip flexor strain
Athletic pubalgia

Correct Answer: Cam-type femoroacetabular impingement

Explanation:

This patient has cam-type femoroacetabular impingement. Decreased internal rotation and a positive impingement test (forced flexion, adduction, and internal rotation) are classic findings. The lack of pain with resisted hip flexion makes hip flexor strain unlikely, and the lack of tenderness at the greater trochanter renders trochanteric bursitis unlikely. Although athletic pubalgia can be a source of longstanding groin pain, he lacks the pain with a resisted sit-up and tenderness along the pubic ramus that is frequently noted in patients with pubalgia. His radiographs reveal a focal femoral neck prominence consistent with cam impingement, although pistol grip deformities and flattening of the lateral femoral head are often present as well. His MRI scan shows a labral tear, which is common in cam impingement. Surgical treatment for cam impingement can be effective for symptomatic patients. Even among high-level athletes, open surgical dislocation of the hip has been shown to have good results. Most patients with cam impingement can be treated with arthroscopic osteoplasty and achieve results comparable with those realized with open surgical dislocation. The literature describes success in terms of athletes returning to sports (even professional athletes) to be approximately 90% after arthroscopic treatment. Byrd and Jones described five patients who developed transient neurapraxias that resolved uneventfully. The patients in his series who had concomitant microfracture had a 92% return to sports within the follow-up period. Cam impingement has long been thought to be associated with a history of a slipped capital femoral epiphysis. The capitis in these patients is displaced posteriorly, resulting in a prominent anterior femoral neck and decreased hip internal rotation. Pincer impingement is associated with a deep acetabulum, such as protrusion acetabula and acetabular retroversion. A patient who underwent a
periacetabular osteotomy can develop a more retroverted acetabulum as well.

Question 12:

What is the most important sign of impending modulation with rapid progression of a spinal deformity in neurofibromatosis?

Options:

Apical curve rotation
Anterior vertebral body erosions
Cervical spine involvement
Penciling of three or more ribs
Curve magnitude of more than 50 degrees

Correct Answer: Penciling of three or more ribs

Explanation:

DISCUSSION: Rib penciling is the only singular factor; 87% of the curves progressed significantly in patients with three or more penciled ribs. Modulation in neurofibromatosis scoliosis implies the change from an idiopathic type to a dysplastic type of curve with rapid progression and the need for aggressive stabilization by fusion.
REFERENCES: Crawford AH, Schorry EK: Neurofibromatosis in children: The role of the orthopaedist. J Am Acad Orthop Surg 1999;7:217-230.
Durrani AA, Crawford AH, Chouhdry SN, et al: Modulation of spinal deformities in patients with neurofibromatosis type 1. Spine 2000;25:69-75.

Question 13:

Options:

bed rest only for 6 weeks.
mobilization in a kinetic therapy bed for 6 weeks, followed by a hyperextension brace.
a total contact thoracolumbosacral orthosis and rapid mobilization.
anterior decompression, vertebral reconstruction, and stabilization.
posterior reduction, stabilization, and grafting.

Correct Answer: a total contact thoracolumbosacral orthosis and rapid mobilization.

Explanation:

Question 14:

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

Options:

C7-T2
T2-T5
T5-T8
T9-T12
T12-L1

Correct Answer: T9-T12

Explanation:

Question 15:

At what age does the lateral epicondyle normally ossify in males?

Options:

2 to 4 years
5 to 6 years
7 to 8 years
9 to 11 years
12 to 14 years

Correct Answer: 12 to 14 years

Explanation:

Question 16:

Plate fixation of olecranon fractures is recommended over tension band wire fixation when

Options:

the fracture is proximal and only involves the olecranon tip.
the fracture is transverse.
the fracture is comminuted.
the fracture is widely displaced.
there is associated osteoporosis.

Correct Answer: the fracture is comminuted.

Explanation:

Question 17:

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 18:

Physiologic bowing of the lower extremities should spontaneously correct by what age?

Options:

3 months
6 months
12 months
36 months
72 months

Correct Answer: 36 months

Explanation:

Question 19:

Options:

Cystinosis
Hypophosphatemia
Renal osteodystrophy
Primary hyperparathyroidism
Nutritional vitamin D deficiency

Correct Answer: Cystinosis

Explanation:

Question 20:

Which of the following anatomic structures is labeled 6 in Figure 27?

Options:

A2 pulley
Grayson’s ligament
Cleland’s ligament
Triangular ligament
Sagittal band

Correct Answer: A2 pulley

Explanation:

Question 21:

Options:

Independent 2-sample t test
Analysis of variance (ANOVA)
Chi-square test
Fisher’s exact test

Correct Answer: Analysis of variance (ANOVA)

Explanation:

Question 22:

Options:

CT
Limited bone scan
MRI
Joint aspiration
Functional capacity examination

Correct Answer: MRI

Explanation:

Question 23:

Options:

Thoracic curve coronal correction of > 40%
Thoracolumbar/lumbar curve coronal correction > 50%
Smaller adolescents (<50 kg)
Failure to maintain lumbar lordosis of > 45 degrees
Thoracic hyperkyphosis (>40 degrees )

Correct Answer: Thoracic hyperkyphosis (>40 degrees )

Explanation:

Question 24:

Options:

Flexor digitorum superficialis (FDS) branch transfer to the extensor carpi radialis brevis (ECRB) branch
Third web space median fascicle transfer to the ulnar sensory fascicle
Flexor carpi ulnaris fascicle (FCU) transfer to the biceps branch
Terminal anterior interosseous nerve (AIN) transfer to the deep ulnar motor fascicle

Correct Answer: Terminal anterior interosseous nerve (AIN) transfer to the deep ulnar motor fascicle

Explanation:

EXPLANATION:
In adults, the repair of high ulnar nerve injuries typically yields incomplete motor recovery and disappointing functional results despite early surgical intervention and careful surgical technique. Early transfer of the terminal branch of the AIN to the deep ulnar motor fascicle can rapidly reinnervate distal targets and potentially preserve motor end plate function in the intrinsic musculature of the hand because of the proximity of the nerve transfer to the target muscle. Sensory deficits due to an ulnar nerve injury
can be restored through a transfer of median sensory fascicles to the distal ulna sensory fascicles. This procedure typically would not be considered at the time of the original surgery, because sensory recovery is more likely than motor recovery in the setting of a high ulnar nerve injury. For radial nerve injuries, wrist extension can be restored through an FDS branch of the median nerve transfer to the ECRB branch of the radial nerve. The FCU fascicle of the ulnar nerve can be transferred to the biceps branch of the
musculocutaneous nerve to restore elbow flexion and supination.

Question 25:

Options:

Arthroscopic debridement alone of the partial rotator cuff tear
Repair of the partial rotator cuff tear and subacromial decompression
Arthroscopic debridement combined with subacromial decompression
Arthroscopic subacromial decompression
Biceps tenotomy

Correct Answer: Repair of the partial rotator cuff tear and subacromial decompression

Explanation:

DISCUSSION: Although arthroscopic debridement with or without subacromial decompression is a reasonable response, the patient has positive impingement signs. Several recent studies regarding the surgical treatment of partial rotator cuff tears have demonstrated good to excellent results after repair of tears involving more than 50% of the tendon thickness. This was shown specifically for bursal-sided tears and joint-side tears. Biceps tenotomy is not indicated in a young patient.
REFERENCES: Matava MJ, Purcell DB, Rudzki JR: Partial-thickness rotator cuff tears.
Am J Sports Med 2005;33:1405-1417.
Fukuda H: The management of partial-thickness tears of the rotator cuff. J Bone Joint Surg Br 2003;85:3-11.

Question 26:

Options:

Immediate spica casting
Flexible intramedullary nail placement
Traction and casting
External fixation
Solid intramedullary nail fixation via the greater trochanter

Correct Answer: Solid intramedullary nail fixation via the greater trochanter

Explanation:

Question 27:

Options:

Inferior gluteal
Medial femoral circumflex
Lateral femoral circumflex
Femoral

Correct Answer: Lateral femoral circumflex

Explanation:

Question 28:

Options:

closed reduction of the glenohumeral joint and open reduction of the displaced greater tuberosity with rotator cuff repair.
closed reduction of the glenohumeral joint, followed by radiographic assessment of the tuberosity position to determine further treatment.
open reduction of both the joint and greater tuberosity with rotator cuff repair.
open reduction of the glenohumeral joint and closed treatment of the greater tuberosity.
use of a sling until the patient reports no discomfort, then early passive range of motion.

Correct Answer: closed reduction of the glenohumeral joint, followed by radiographic assessment of the tuberosity position to determine further treatment.

Explanation:

Question 29:

Options:

A + C
B + C
B + D
C + D
C + E

Correct Answer: A + C

Explanation:

Question 30:

Halo treatment for preadolescent children typically requires the use of which of the following? Review Topic

Options:

4 to 6 pins with an insertional torque of 1 to 5 in-lb
4 to 6 pins with an insertional torque of 4 to 6 in-lb
4 to 6 pins with an insertional torque of 6 to 8 in-lb
8 to 12 pins with an insertional torque of 1 to 5 in-lb
8 to 12 pins with an insertional torque of 4 to 6 in-lb

Correct Answer: 8 to 12 pins with an insertional torque of 1 to 5 in-lb

Explanation:

Question 31:

Options:

Interleukin-2-based chemotherapy
Embolization followed by curettage, intramedullary fixation, and cementation
Embolization followed by curettage and cementation
External beam radiation
Total humeral resection and prosthetic reconstruction

Correct Answer: Embolization followed by curettage, intramedullary fixation, and cementation

Explanation:

Question 32:

- A skeletal survey is more accurate than a bone scan for detecting skeletal involvement in which of the following neoplastic diseases?

Options:

Ewing’s sarcoma
Osteogenic sarcoma
Multiple myeloma
Metastatic prostate carcinoma
Metastatic breast carcinoma

Correct Answer: Multiple myeloma

Explanation:

Multiple Myeloma lesions are cold on bone scan and because of this a skeletal survey is more useful.

Question 33:

What is the most common nonanesthetic-related reversible cause of changes in intraoperative neurophysiologic monitoring data?

Options:

Pedicle screw misplacement
Patient positioning
Spinal cord ischemia
Retractor placement
Hypotension

Correct Answer: Patient positioning

Explanation:

DISCUSSION: Patient positioning that results in local nerve compression, plexus traction, or improper neck alignment is the most common nonanesthetic-related cause of changes in intraoperative neurophysiologic monitoring data during spinal surgery.
REFERENCES: Jones SC, Fernau R, Woeltjen BL: Use of somatosensory evoked potentials to detect peripheral ischemia and potential injury resulting from positioning of the surgical patient: Case reports and discussion. Spine J 2004;4:360-362.
Schwartz DM, Sestokas AK, Hilibrand AS, et al: Neurophysiological identification of position-induced neurologic injury during anterior cervical spine surgery. J Clin Monit Comput 2006;20:437-444.

Question 34:

Options:

Retain the components, and implant a tibial strut allograft.
Revise the tibial component with a metaphyseal cone and metaphyseal uncemented stem.
Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.
Revise the tibial component with a long cemented diaphyseal-engaging stem.

Correct Answer: Revise the tibial component with a metaphyseal cone and a press-fit diaphyseal-engaging stem.

Explanation:

Question 35:

Options:

closed reduction and casting in extension.
open reduction with suture fixation of the proximal fragment.
closed reduction, followed by functional bracing.
open reduction and internal fixation with screws and complete proximal tibial epiphysiodesis.
open reduction and internal fixation with screws.

Correct Answer: open reduction and internal fixation with screws.

Explanation:

Question 36:

Options:

open reduction and internal fixation.
excision of the radial head.
excision of the radial head and prosthetic arthroplasty.
a long arm cast.
a sling and early range-of-motion exercises.

Correct Answer: a sling and early range-of-motion exercises.

Explanation:

DISCUSSION: The radiographs show a small minimally displaced radial head fracture that is amenable to nonsurgical management. Early range-of-motion exercises will best restore
function and minimize stiffness. A long arm cast for any length of time will result in severe elbow stiffness.
REFERENCES: Morrey BF: Radial head fracture, in Morrey BF (ed): The Elbow and Its Disorders, ed 3. Philadelphia, PA, WB Saunders, 2000, pp 341-364.
Hotchkiss RN: Displaced fractures of the radial head: Internal fixation or excision? J Am Acad Orthop Surg 1997;5:1-10.

Question 37:

Options:

Closed reduction with immobilization
Closed reduction with percutaneous pinning
Open reduction, bicolumnar fixation with plate and screws
Open reduction, bicolumnar fixation with Kirschner wires DISCUSSION.. The radiographs and CT scans indicate a comminuted and displaced intra-articular fracture of the distal humerus. Rigid internal fixation with bicolumnar orthogonal or parallel plating is the treatment of choice for most fractures of the distal humerus that involve the joint surface. Closed reduction and variations thereof will not yield a stable environment for healing. To achieve adequate exposure for fixation, a chevron olecranon osteotomy is the preferred approach. Disadvantages associated with this approach include complications such as nonunion of the osteotomy site and intra-articular adhesions. Prominent hardware may need to be removed during a secondary procedure, and intraoperative conversion to an elbow arthroplasty may be limited. The most common complications after open reduction and internal fixation include elbow stiffness, nonunion (2%-10%), and ulnar neuropathy (0%-12%).

Correct Answer: Open reduction, bicolumnar fixation with plate and screws

Explanation:

CLINICAL SITUATION FOR QUESTIONS 84 THROUGH 87
Figure 84 is the glenoid CT scan of a 20-year-old man who dislocated his shoulder anteriorly while playing football. He had persistent instability 2 months after the injury, but he did not have a sulcus sign or posterior instability. He underwent an arthroscopic Bankart repair with 4 bioabsorbable anchors with simple sutures through the labrum and capsule.
He did not have an engaging Hill-Sachs lesion, the rotator cuff was unremarkable, and the capsule was not torn from the humerus. After surgery, he did well for 6 months until he jumped into a lake and again dislocated his shoulder anteriorly. He says his shoulder no longer felt stable after his reduction.

Question 38:

Options:

Consultation with an infectious disease specialist
Symptomatic treatment, with a full return to activities in 4 to 6 weeks
Cast immobilization for 6 to 12 weeks with the expectation of full recovery
A rheumatologic work-up with the expectation of significant long-term sequelae
Bone biopsy

Correct Answer: Cast immobilization for 6 to 12 weeks with the expectation of full recovery

Explanation:

Question 39:

Options:

extensor digitorum brevis.
plantar fascia.
peroneus brevis.
peroneus longus.
syndesmosis.

Correct Answer: peroneus longus.

Explanation:

Question 40:

Which of the following methods is effective in correcting recurrent dislocation following total hip arthroplasty?

Options:

Lateralization of the greater trochanter without advancement
Use of a shorter neck length
Use of a constrained acetabular component
Use of a small diameter head
High cup abduction angle

Correct Answer: Use of a constrained acetabular component

Explanation:

Question 41:

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

Options:

Crutches and no weight bearing
Core decompression
Shoe inserts
Temporary cast immobilization
Nonsteroidal anti-inflammatory drugs

Correct Answer: Temporary cast immobilization

Explanation:

DISCUSSION: While Köhler’s disease has a benign course, temporary cast immobilization has been shown to result in a shortened duration of symptoms. Core decompression or other surgery is not warranted because of the benign nature. Shoe inserts may be beneficial, but there are no studies to support their use.
REFERENCES: Borges JL, Guile JT, Bowen JR: Köhler’s bone disease of the tarsal navicular.
J Pediatr Orthop 1995;15:596-598.
Williams GA, Cowell HR: Köhler’s disease of the tarsal navicular. Clin Orthop 1981;158:53-58.

Question 42:

During particle-induced osteolysis around implants, what cell secretes most of the interleukin-6 (IL-6)?

Options:

Osteoblasts from surrounding bone
B-lymphocytes in the bone marrow
Fibroblastic cells in the periprosthetic lining
T-lymphocytes in the circulating blood
Macrophages in the granuloma

Correct Answer: Fibroblastic cells in the periprosthetic lining

Explanation:

Question 43:

Options:

immobilization of the wrist until the fracture heals.
excision of the hook of the hamate.
internal fixation of the fractured hook of the hamate.
ultrasound therapy to promote fracture healing.
limited intercarpal arthrodesis.

Correct Answer: immobilization of the wrist until the fracture heals.

Explanation:

Question 44:

Options:

Ankle ligament repair
Resection of the accessory navicular
Resection of the talocalcaneal coalition
Subtalar arthrodesis
Triple arthrodesis

Correct Answer: Resection of the talocalcaneal coalition

Explanation:

Question 45:

Which of the following best characterizes the antigenicity of allograft bone?

Options:

Cell surface glycoproteins are primarily responsible for the antigenicity of the graft.
Fresh grafts have less antigenicity than cryopreserved grafts.
Immunosupression provides little difference in response to allogenic bone.
Hematopoietic elements are the primary cells causing antigenic response.
Lyophilization (freeze-drying) or chemical sterilization does not change the antigenicity of the graft.

Correct Answer: Cell surface glycoproteins are primarily responsible for the antigenicity of the graft.

Explanation:

Question 46:

Options:

Physical therapy
Arthroscopic labral repair
Arthroscopic subscapularis repair
Arthroscopic thermal capsular shift
Open Bankart repair

Correct Answer: Physical therapy

Explanation:

Question 47:

Options:

MRI
Serum inflammatory markers and biopsy
Bone scan
Weight bearing cast
Non-weight bearing cast

Correct Answer: Serum inflammatory markers and biopsy

Explanation:

This child has Kohler's disease of the navicular. Weight-bearing cast immobilization (for 4-6weeks) is appropriate. Splinting for 2 weeks is insufficient.
Idiopathic avascular necrosis (AVN) of the navicular arises because the intraosseous blood flow of the navicular is centripetal, leaving a central watershed area. The primary blood supply is via perforating branches of the dorsalis pedis. Patients present with midfoot pain between 2-9 years of age. Navicular sclerosis, fragmentation, and flattening are noted radiographically.
Digiovanni et al. reviewed AVN in the foot. Nonsurgical management is routine. Cast immobilization will provide earlier resolution of symptoms. Weight-bearing will not affect outcome. The navicular will regain a normal appearance over time.
Aiyer and Hennrikus reviewed pediatric foot pain. That state that up to 25% of Kohler's disease is bilateral. They agree that casting for 4-6weeks will mitigate symptoms and increase the rate of symptom resolution.
Figures A through C are AP, oblique and lateral foot radiographs showing navicular flattening and sclerosis consistent with Kohler's disease.
Incorrect Answers:
(SBQ13PE.29) A 10-year-old girl presents to your office accompanied by her mother to discuss cosmetic concerns regarding her feet pictured in Figure A. They recently migrated to the U.S. and this is the first medical evaluation for this complaint. The father's feet apparently look similar. The remainder of the patient's physical
examination is normal. The parents should be counseled that children with this condition have:
Review Topic
Delayed motor milestones, and cardiac and renal work up are necessary
Normal motor milestones, but cardiac and renal work up are necessary
Delayed motor milestones, but no further work up is necessary
Normal motor milestones, and no further work up is necessary
No chance of passing on this trait to children, as it results from a spontaneous genetic mutation
This patient has post-axial polydactyly of the feet. Children with this condition exhibit normal motor milestones. If the remainder of the physical examination is normal, no further work up is necessary.
Post-axial polydactyly is a common autosomal dominant trait. As such, there is usually a family history. In the absence of other physical exam abnormalities, this condition is not associated with systemic disorders. Normal motor development can be expected, though surgical treatment may be undertaken to facilitate cosmesis or shoe-wear.
Phelps et al. reviewed supernumerary digits in 61 patients at an average of 15 year follow up. They found 94% good to excellent results. Poor results were associated with pre-axial duplications and persistent hallux varus.
Figure A is a clinical photo showing bilateral post-axial polydactyly of the foot. Incorrect answers:
cardiac or renal conditions without any manifestations. Answer 5. This is an autosomal dominant condition.

Question 48:

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

Options:

Rupture of the medial collateral ligament
Rupture of the lateral collateral ligament
Intra-articular loose body
Flexor-pronator injury
Extensor origin avulsion

Correct Answer: Rupture of the medial collateral ligament

Explanation:

DISCUSSION: MRI arthrography is the imaging study of choice for evaluation of medial collateral ligament injuries.
REFERENCES: Carrino JA, Morrison WB, Zou KH, et al: Noncontrast MR imaging and MR arthrography of the ulnar collateral ligament of the elbow: Prospective evaluation of two-dimensional pulse sequences for detection of complete tears. Skeletal Radiol 2001;30:625-632.
Munshi M, Pretterklieber ML, Chung CB, et al: Anterior bundle of ulnar collateral ligament: Evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis. Radiology 2004;231:797-803.

Question 49:

Options:

an MRI of the shoulder.
a physical therapy referral for rotator cuff strengthening and proprioceptive exercise.
a home stretching program and corticosteroid injection.
arthroscopic glenohumeral capsular release. DISCUSSION.. This patient has idiopathic adhesive glenohumeral stiffness. Most patients with this condition are women between 40 and 60 years of age with no specific mechanism of onset. Patients typically develop pain, at which point the disease is marked by significant inflammation. This patient is likely in the second stage of the disease, marked by inflammation and early fibrosis of the joint capsule, leading to joint stiffness. Associated conditions include diabetes mellitus and hypothyroidism, although there is no explainable cause for most cases. The most appropriate treatment step at this stage is an intra-articular glenohumeral corticosteroid injection, most often in conjunction with either a supervised or home-based capsular stretching program. Physical therapy that prioritizes toward rotator cuff strengthening is more appropriate for patients with isolated subacromial impingement syndrome and may worsen symptoms in patients with stiff shoulders. An MRI scan likely would not alter initial treatment for patients who are stiff at presentation. Arthroscopic glenohumeral capsular release is reserved for those patients who fail initial attempts at nonsurgical management and remain functionally limited.

Correct Answer: a home stretching program and corticosteroid injection.

Explanation:

Question 50:

Options:

Cemented left total hip arthroplasty (THA)
Cementless left THA with a proximally porous coated femoral stem
Hybrid left THA
Cementless left THA with a diaphyseal engaging conical femoral stem

Correct Answer: Hybrid left THA

Explanation:

Question 51:

Options:

infection.
instability.
loosening.
periprosthetic fracture.

Correct Answer: instability.

Explanation:

Question 52:

Which of the following activities can improve posterior capsular contractures?

Options:

Theraband exercises to strengthen the external rotator
Latissimus pull-down exercises to the chest
Seated rows
Internal rotation stretch at 90 degrees abduction with scapular stabilization
Bench press with wide grip

Correct Answer: Internal rotation stretch at 90 degrees abduction with scapular stabilization

Explanation:

Question 53:

Options:

Complex regional pain syndrome
Wartenberg’s syndrome
Carpal tunnel syndrome
Palmar cutaneous nerve injury
C7 radiculopathy

Correct Answer: Palmar cutaneous nerve injury

Explanation:

DISCUSSION: The palmar cutaneous branch of the median nerve separates from the median nerve approximately 4 to 6 cm proximal to the wrist crease and travels between the median nerve and the flexor carpi radialis tendon. It supplies the skin of the thenar region. This nerve is at risk for injury with retraction of the digital flexor tendons in plating the distal radius. Wartenberg’s syndrome is compression of the superficial radial nerve which innervates the dorsum of the thumb and the first dorsal web space. Carpal tunnel syndrome causes dysesthesias of the thumb, index, and/or middle fingers. C7 radiculopathy affects the index and middle fingers.
REFERENCES: Jupiter JB, Fernandez DL, Toh CL, et al: Operative treatment of volar intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am 1996;78:1817-1828.
Hoppenfield S, deBoer P (eds): Surgical Exposures in Orthopaedics: The Anatomic Approach, ed 2. Philadelphia, PA, JB Lippincott, 1994, pp 156-176.

Question 54:

Options:

Incomplete corticotomy
Knee subluxation
Wire breakage
Poor regenerate bone formation
Premature consolidation

Correct Answer: Premature consolidation

Explanation:

DISCUSSION: Premature consolidation is a complication that is unique to gradual bone lengthening after corticotomy. Causes include excessive latency period, inadequate distraction rate, exuberant bone formation, patient compliance problems, and mechanical failure of the distraction apparatus. The femur and fibula are most commonly involved. This patient did not have an incomplete corticotomy, as initial distraction occurred before the distraction device was noted to seize up. The radiographs show bowing of the Ilizarov wires and mature regenerate bone, both suggestive of premature consolidation. No wire breakage or joint subluxation is seen on the radiographs. Treatment for premature consolidation includes continuing distraction until the consolidation bridge ruptures, or additional surgery may include closed rotational osteoclasis or repeat corticotomy.
REFERENCES: Paley D: Problems, obstacles and complications of limb lengthening, in Maiocchi AB, Aronson J (eds): Operative Principles of Ilizarov. Baltimore, MD, Williams & Wilkins, 1991, p 360.
Herring JA: Limb length discrepancy, in Herring JA (ed): Tachdjian’s Pediatric Orthopaedics,
ed 3. Philadelphia, PA, WB Saunders, 2002, p 1088.

Question 55:

Options:

History of malunited proximal humerus fracture
Proximal humeral bone loss
Failed primary arthroplasty
Rheumatoid arthritis
Fixed preoperative glenohumeral dislocation

Correct Answer: History of malunited proximal humerus fracture

Explanation:

Question 56:

Options:

Displaced labral tear
Tear of the rotator cuff
Fracture of the glenoid rim
Palsy of the axillary nerve
Palsy of the musculocutaneus nerve

Correct Answer: Tear of the rotator cuff

Explanation:

Question 57:

Figure 93 shows the axial T2-weighted MRI scan of the lumbar spine of a 70-year-old man. The arrow points to which of the following structures? Review Topic

Options:

Lamina
Facet joint
Lumbar synovial cyst
Ligamentum flavum
Epidural space

Correct Answer: Lamina

Explanation:

The ligamenta flava (singular, ligamentum flavum, Latin for yellow ligament) are ligaments that connect the laminae of adjacent vertebra, all the way from the axis to the first segment of the sacrum. In T2-weighted sequencing, ligamentous structures possess a low signal intensity. The ligamentum in this patient is markedly thickened, resulting in severe spinal stenosis. The epidural space lies ventral and medial to the ligamentum flavum and should possess a high signal intensity secondary to the presence of cerebrospinal fluid. However, in the case of high-grade stenosis, there may be little if any cerebrospinal fluid present, making the epidural space and central canal difficult to identify. A lumbar synovial cyst should also have high signal intensity because of the presence of synovial fluid.
(SBQ12SP.14) A 36-year-old male presents with acute onset of right buttock and leg pain following lifting a heavy object. On physical exam he has weakness to knee extension, numbness over the medial malleolus, and a decreased patellar reflex. Which of the following would most likely explain this clinical presentation.
Review
Topic
Lumbar arachnoiditis
L4/L5 paracentral disc herniation
L3/L4 far lateral (foraminal) disc herniation
L4/L5 far lateral (foraminal) disc herniation
L5/S1 far lateral (foraminal) disc herniation
The clinical presentation is consistent with a L4 radiculopathy. A L4/L5 far lateral (foraminal) disc herniation would compress the exiting root (L4) and cause these symptoms.
The location of a prolapsed lumbar disc determines its symptoms. Central disc herniations may give rise to back pain or cauda equina syndrome. Paracentral disc herniations (90-95% of cases) affect the traversing nerve root. Far lateral disc herniations (5-10%) affect the exiting nerve root.
Gregory et al. summarize physical signs in lumbar disc herniation. They state that the straight-leg-raise is the most sensitive (73-98% sensitive) test and the crossed straight-leg-raise is the most specific (88-98% specific) test for lumbar disc herniation. Other specific tests include weak ankle dorsiflexion (89% specific), absent ankle reflex (89% specific), and calf wasting (94% specific, but a late finding).
Illustration A shows how a paracentral L4/L5 disc herniation affects the traversing L5 root, but a far lateral L4/L5 disc herniation affects the L4 root. Illustration B shows the dermatomal distribution of pain with root involvement from L3 to S1.
Incorrect Answers:

Question 58:

Figure A shows the 2 bundles of the ACL dissected from a cadaveric knee off their bony attachments. They are labeled Bundle A and Bundle B, respectively. Which of the following is true? Review Topic

Options:

The tibial attachment of Bundle A is anterior to Bundle B. In extension, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle A is anterior to Bundle B. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle B is loose and Bundle A is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle A is loose and Bundle B is tight.
The tibial attachment of Bundle B is anterior to Bundle A. In extension, Bundle A is loose and Bundle B is tight.

Correct Answer: The tibial attachment of Bundle A is anterior to Bundle B. In extension, Bundle B is loose and Bundle A is tight.

Explanation:

Question 59:

Which of the following conditions is associated with palmoplantar pustulosis?

Options:

Condensing osteitis
Sternoclavicular hyperostosis
Friedreich’s disease
Scleroderma
Reiter syndrome

Correct Answer: Sternoclavicular hyperostosis

Explanation:

DISCUSSION: Sternoclavicular hyperotosis is a seronegative and HLA-B27 negative rheumatic disease. In this condition, hyperostosis may appear in the spine, long bones, sacroiliac joints, and the sternoclavicular region. This entity is also associated with palmoplantar pustulosis.
REFERENCES: Wirth MA, Rockwood CA: Disorders of the sternoclavicular joint, in Rockwood CA, Matsen FA, Wirth MA, et al (eds): The Shoulder. Philadelphia, PA,
WB Saunders, 2004, vol 2, pp 608-609.
Sonozaki H, Azuma A, Okai K, et al: Clinical features of 22 cases with inter-sterno-costo-clavicular ossification: A new rheumatic syndrome. Arch Orthop Trauma Surg 1979;95:13-22.

Question 60:

Figures 9a and 9b are the radiographs of a 19-year-old woman with a painful juvenile bunion. The pathologic findings associated with this deformity include a

Options:

Laterally deviated distal metatarsal articular surface, a
lax or disrupted distal 1-2 transverse intermetatarsal 12
ligament, and a contracted lateral collateral (lateral first
metatarsophalangeal) ligament.
Laterally deviated distal metatarsal articular surface, a contracted lateral collateral (lateral first metatarsophalangeal) ligament, and a medially deviated or hypermobile first metatarsocuneiform joint.
Medially deviated or hypermobile first metatarsocuneiform joint, a lax or disrupted distal 1-2 transverse intermetatarsal ligament, and a contracted lateral collateral (lateral first metatarsophalangeal) ligament.
Lax or disrupted distal 1-2 transverse intermetatarsal ligament, laterally deviated distal metatarsal articular surface, and a medially deviated or hypermobile first metatarsocuneiform joint.

Correct Answer: lax or disrupted distal 1-2 transverse intermetatarsal 12

Explanation:

Question 61:

Options:

open reduction and internal fixation.
percutaneous pin fixation.
excision of the fracture fragment.
primary calcaneocuboid joint arthrodesis.
a walking cast or removable cast boot.

Correct Answer: a walking cast or removable cast boot.

Explanation:

Question 62:

An eversion mechanism of injury is associated with which of the following ankle conditions?

Options:

Peroneal tendon splits
Osteochondral talar dome fracture
Superficial peroneal nerve palsy
Anterolateral soft-tissue impingement
Fracture of the anterior colliculus

Correct Answer: Fracture of the anterior colliculus

Explanation:

Question 63:

Options:

cryoablation with liquid nitrogen.
topical salicylic acid application.
first metatarsal dorsiflexion osteotomy.
sesamoidectomy.
sesamoid shaving.

Correct Answer: sesamoid shaving.

Explanation:

Question 64:

Figure 6 shows an object being held in an outstretched hand. To offset the moment created by the object (ignoring the weight of the forearm), the biceps must generate a force of

Options:

5 N.
15 N.
30 N.
75 N.
150 N.

Correct Answer: 75 N.

Explanation:

Question 65:

Options:

Stiffness of the wrist joint
Physeal growth arrest
Physeal overgrowth
Osteonecrosis of the metaphysis
Posttraumatic arthritis

Correct Answer: Physeal growth arrest

Explanation:

Question 66:

- A 14-year-old girl has idiopathic scoliosis with a 52-degree right thoracic curve and a 36-degree left lumbar curve. The rotation of the apical vertebra appears greater in the thoracic curve. A sagittal view radiograph shows the spine to be virtually straight. The iliac apophyses are Risser 2. Treatment should consist of

Options:

Anterior fusion of the lumbar curve
Anterior and posterior fusion of the thoracic curve
Posterior fusion of the thoracic curve
Posterior fusion of the thoracic and lumbar curves
Application of a brace until the iliac apophyses are Risser 4 or 5, followed by surgical correction

Correct Answer: Posterior fusion of the thoracic curve

Explanation:

Question 67:

Options:

Place a medial pin to further stabilize the fracture
Remove all of the pins and displace the fracture
Obtain an emergent CT angiogram to assess arterial flow
Explore the artery
Splint the arm in extension as the fracture is now stabilized

Correct Answer: Explore the artery

Explanation:

Question 68:

Options:

The right T2 pedicle screw is well seated within the pedicle.
The right T2 pedicle screw has breached the pedicle wall and has violated the costovertebral junction.
There is a breach in the right T2 pedicle wall, but the screw is not in contact with a neural structure.
There is a breach in the right T2 pedicle and the screw is in contact with a neural structure.

Correct Answer: There is a breach in the right T2 pedicle and the screw is in contact with a neural structure.

Explanation:

DISCUSSION
This patient has developed a proximal junctional kyphosis following a long posterior fusion performed for treatment of degenerative lumbar scoliosis. Risk factors for proximal junctional kyphosis in the setting of instrumented fusions performed for degenerative scoliosis include advanced age, 360-
degree fusions, extension of fusion constructs to the sacrum, and upper instrumented vertebrae at the level of T1-3. The patient's junctional kyphosis is attributable to failure of the disk and ligamentous structures at T2-3 and would be graded as type I using the classification system of Yagi and associates. Most symptomatic proximal junctional kyphoses are treated with posterior extension of the fusion construct to a more proximal level spanning the kyphosed region. The use of orthoses or simple removal of instrumentation is unlikely to substantively impact symptoms or address the proximal kyphosis. Diabetes and obesity are known factors that increase risk for postsurgical infection following a spine fusion procedure. The most frequent complication following revision surgery for proximal junctional kyphosis, however, is the need for further surgery. In the study by Yagi and associates, 48% of patients who underwent revision surgery for proximal kyphosis developed further adjacent segment degeneration. In the proximal thoracic spine, where the pedicle may be narrow, triggered EMG testing of inserted pedicle screws may be used to assess for violation of the pedicle wall during insertion. In the setting of triggered EMG, thresholds exceeding 10 mA indicate a well-placed pedicle screw. Thresholds lower than 4 mA to 6 mA indicate that a screw is directly contacting a neural structure. Thresholds between 9 mA and 10 mA suggest that a breach of the pedicle may be present, but the screw is not contacting a neural structure.
RECOMMENDED READINGS
Yagi M, Rahm M, Gaines R, Maziad A, Ross T, Kim HJ, Kebaish K, Boachie-Adjei O; Complex Spine Study Group. Characterization and surgical outcomes of proximal junctional failure in surgically treated patients with adult spinal deformity.Spine (Phila Pa 1976). 2014 May 1;39(10):E607-14. doi: 10.1097/BRS.0000000000000266. PubMed PMID: 24525992.
View
Abstract at PubMed
Cammarata M, Aubin CÉ, Wang X, Mac-Thiong JM. Biomechanical risk factors for proximal junctional kyphosis: a detailed numerical analysis of surgical instrumentation variables. Spine (Phila Pa 1976). 2014 Apr 15;39(8):E500-7. doi: 10.1097/BRS.0000000000000222. PubMed
PMID: 24480964.
View Abstract at PubMed
Kim HJ, Lenke LG, Shaffrey CI, Van Alstyne EM, Skelly AC. Proximal junctional kyphosis as a distinct form of adjacent segment pathology after spinal deformity surgery: a systematic review. Spine (Phila Pa 1976). 2012 Oct 15;37(22 Suppl):S144-64. doi: 10.1097/BRS.0b013e31826d611b. PubMed PMID: 22885829.
View Abstract at PubMed
Schoenfeld AJ, Carey PA, Cleveland AW 3rd, Bader JO, Bono CM. Patient factors, comorbidities, and surgical characteristics that increase mortality and complication risk after spinal arthrodesis: a prognostic study based on 5,887 patients. Spine J. 2013 Oct;13(10):1171-9. doi: 10.1016/j.spinee.2013.02.071. Epub 2013 Apr 9. PubMed PMID:

Question 69:

When planning a research study, the power of the study may be increased by

Options:

performing a retrospective study.
performing a prospective study.
using a case control design.
decreasing the sample size.
increasing the sample size.

Correct Answer: increasing the sample size.

Explanation:

Question 70:

Options:

Bushing wear
Infection
Aseptic component loosening
Component fracture

Correct Answer: Bushing wear

Explanation:

Question 71:

Options:

Weight bearing as tolerated in all extremities
Early protected weight bearing right lower extremity in walking cast, weight bearing as tolerated left upper extremity, non-weight bearing right forearm
Weight bearing as tolerated in bilateral lower extremities and right upper extremity, non-weight bearing left upper extremity
Non-weight bearing bilateral upper extremities and right lower extremity
Non-weight bearing right upper and lower extremities, weight bearing as tolerated left upper and lower extremities without walking cast

Correct Answer: Weight bearing as tolerated in all extremities

Explanation:

Question 72:

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

Options:

Patellar
Popliteal
Semitendinosus
Semimembranosus
Biceps femoris

Correct Answer: Popliteal

Explanation:

Question 73:

Options:

Conversion to a total shoulder arthroplasty
Conversion to a reverse shoulder arthroplasty
Continued physical therapy
Cortisone injection
Anti-inflammatory medication

Correct Answer: Conversion to a reverse shoulder arthroplasty

Explanation:

Question 74:

Options:

pneumatic compression stockings.
subcutaneous heparin administration.
a heparin bolus followed by therapeutic heparin anticoagulation.
warfarin anticoagulation.
placement of a vena cava filter.

Correct Answer: placement of a vena cava filter.

Explanation:

Question 75:

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

Options:

intralesional.
marginal.
wide.
wide contaminated.
radical.

Correct Answer: intralesional.

Explanation:

Question 76:

Etanercept is a recombinant genetically engineered fusion protein used to treat rheumatoid arthritis. What is its mode of action?

Options:

Monoclonal antibody that binds TNF-α
Blocks the binding of IL-1 to receptors
Soluble receptor that binds TNF-α
Soluble factor that binds rheumatoid factor
Directly inhibits pyrimidine synthesis

Correct Answer: Soluble receptor that binds TNF-α

Explanation:

Question 77:

Options:

No additional consent needed
Verbal approval
Written approval
Written approval with notarization
Telephone consent witnessed by a nurse

Correct Answer: No additional consent needed

Explanation:

Question 78:

Options:

peripheral myelin protein 22.
connexin 32.
survival motor neuron.
neurofibromin.
frataxin.

Correct Answer: survival motor neuron.

Explanation:

Question 79:

Options:

tuberosity and rotator cuff repair with bone graft.
revision arthroplasty leaving the prosthesis proud to increase humeral length and muscle tension.
revision total shoulder arthroplasty to neutralize eccentric glenoid wear.
revision of the humeral head replacement alone with increased retroversion.
additional therapy to include internal and external rotation strengthening of the rotator cuff.

Correct Answer: tuberosity and rotator cuff repair with bone graft.

Explanation:

Question 80:

Figure 13 is the photograph of 18-month-old triplets with a lower-limb condition. What is the best initial treatment? Review Topic

Options:

Vitamin D supplementation and serum level monitoring
Mechanical axis alignment measurements on serial standing knee radiographs
Genetic testing and counseling for short-stature syndrome
Observation and clinical follow-up.

Correct Answer: Mechanical axis alignment measurements on serial standing knee radiographs

Explanation:

These triplets exhibit genu varum and internal tibial torsion that can be part of normal development. Fetal packing is the likely major contributing cause for these triplets, however. Observation and follow-up will be sufficient. Bowing and torsion can be clinical features of vitamin D deficiency, Blount disease, and short-stature syndromes, but these are not the most likely diagnoses. Radiographic diagnosis of Blount disease may not be accurate at this age.
(SBQ13PE.56) A 22-month-old female is hospitalized with a fever and malaise. She is found to be bacteremic, and blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). During her hospitalization, the pediatrician notices her arm is slightly swollen and appears painful to use. MRI is obtained and demonstrated in figure A. Which feature of the MRI suggests the need for surgical management?
Review Topic
Brodie's Abscess
Osteomyelitis of the humeral metaphysis
Subperiosteal abscess of the humerus
Presence of subcutaneous air
High risk of proximal humeral growth arrest
This patient has osteomyelitis of the humerus with a large subperiosteal abscess. The presence of subperiosteal abscess necessitates surgical intervention for irrigation and debridement (I&D).
The diagnosis of acute osteomyelitis in children is made based upon a constellation of findings including pain, systemic signs of infection, elevated serum inflammatory markers, and imaging studies demonstrative of osseous infection. It is most commonly hematogenously spread to the metaphysis of immature bone, which is highly vascular prior to skeletal maturity. Treatment involves obtaining specimen for culture, empiric antibiotic treatment, and surgical irrigation and debridement of known abscesses. The end-point of treatment is return of pain-free functionality and the resolution of local/systemic signs of infection.
Conrad reviewed the management of acute hematogenous osteomyelitis and emphasized that surgical intervention in the presence of abscess can be both therapeutic and diagnostic: I&D can obtain culture and narrow the antibiotic plan.
Jones et. al. reviewed chronic pediatric osteomyelitis and report that surgery is the mainstay of treatment because removal of dead bone is essential for resolution of infection. This may be performed with sequestrectomy and curettage, with an emphasis on prevention of pathologic fracture, growth disturbances, bone loss, joint involvement, and permanent loss of function.
Figure A is a coronal STIR MRI image of the humerus demonstrating osteomyelitis
with extensive subperiosteal abscess.
Incorrect Answers:
Brodie's abscess is a type of subacute osteomyelitis which remains indolent and creates a focal intra-osseous abscess. This is not demonstrated in the clinical image.
The patient does have osteomyelitis of the humeral metaphysis, but this alone is not the indication for surgery. Uncomplicated osteomyelitis may be treated effectively with antibiotics alone.
Presence of subcutaneous air is suggestive of necrotizing fasciitis, which is a surgical emergency. The MRI however does not demonstrate this finding.
The infection and its surgical management both increase risk of injury to the proximal humeral physis and has the potential for growth arrest or angular deformity.
(SBQ13PE.3) Figure A demonstrates a physical examination maneuver in a 1 month old infant. What is this maneuver?
Review Topic
Ortolani Test
Barlow Test
Galeazzi Sign
Patrick test
Teratologic Sign
Figure A shows a schematic image of the Ortalani test.
The Ortolani test, or Ortolani maneuver, is part of the physical examination for developmental dysplasia of the hip. It is used alongside the Barlow test to detect subluxated hips that are either reducible or irreducible. A positive sign is a distinctive 'clunk' which can be heard and felt as the femoral head relocates anteriorly into the acetabulum.
Guille et al. showed that the use of Pavlik harness has become the mainstay of initial treatment for the infant who has not yet begun to stand. If concentric reduction of the hip cannot be obtained, surgical reduction of the dislocated hip is the next step before they are able to stand.
Video V is a lecture discussing the hip examination of the infant. Incorrect Answers:
pressure on the knee, directing the force the femoral head posteriorly. A positive Barlow test would result in posterior subluxation/dislocation of the hip. Answer 3: Galeazzi test is performed by flexing an infant's knees in the supine position so that the ankles touch the buttocks. If the knees are not level then the test is positive, which indicates a potential congenital hip issue (e.g. DDH). Answer 4: Patrick or Faber test (flexion, abduction, external rotation) has been described both for stressing the SI joint and for isolating symptoms to the hip Answer 5: Teratologic dislocation of the hip is a term used to imply that the hip joint did not develop normally in utero, thus the hip is in a fixed dislocated position at birth.

Question 81:

Options:

Subtalar fusion
Posterior tibial tendon transfer to the cuboid
Split posterior tibial tendon transfer to the lateral cuneiform
Flexor digitorum longus transfer to the fifth metatarsal
Excision of both the peroneus longus and brevis

Correct Answer: Flexor digitorum longus transfer to the fifth metatarsal

Explanation:

DISCUSSION: A flexor digitorum longus transfer, while not as strong as the peroneals, improves the tendon balance and maintains hindfoot mobility. Subtalar fusion is a salvage procedure. Posterior tibial tendon transfer compromises inversion strength and arch height. Functional absence of the peroneals results in an imbalance that could lead to forefoot varus.
REFERENCES: Redfern D, Myerson M: The management of concomitant tears of the peroneus longus and brevis tendons. Foot Ankle Int 2004;25:695-707.
Borton DC, Lucas P, Jomha NM, et al: Operative reconstruction after transverse rupture of the tendons of both peroneus longus and brevis: Surgical reconstruction by transfer of the flexor digitorum longus tendon. J Bone Joint Surg Br 1998;80:781-784.

Question 82:

Options:

immediate repair of the ruptured patellar tendon insertion.
knee joint aspiration and injection of a local anesthetic to facilitate examination.
joint aspiration for culture, broad-spectrum antibiotics, and immobilization.
immobilization until comfortable, followed by protected range of motion and strengthening.
immediate fracture repair.

Correct Answer: immobilization until comfortable, followed by protected range of motion and strengthening.

Explanation:

Question 83:

Options:

Bracing and molded wheelchair inserts
Anterior release and fusion from T2 to L5
Anterior release and fusion from T10 to L3 and posterior fusion from T2 to pelvis
Posterior fusion from T2 to pelvis
Posterior fusion from T2 to L4

Correct Answer: Bracing and molded wheelchair inserts

Explanation:

This patient has a large cerebral palsy (CP) scoliotic curve with pelvic obliquity. Posterior instrumentation should be from T2 to the pelvis.
Scoliosis in CP differs from adolescent idiopathic scoliosis. Curves can be classified into double curves (thoracic and lumbar) with minimal pelvic obliquity (Weinstein Group I) and large curves (lumbar/thoracolumbar) with marked pelvic obliquity (Group II). In the presence of pelvic obliquity (>15°), caudal instrumentation should end at the pelvis to reduce the risk of pseudoarthrosis and late loss of correction. Cephalad instrumentation should end high in the thoracic spine (T2) to decrease proximal junctional kyphosis.
Imrie et al. reviewed the management of spinal deformity in CP. They advocate posterior-only pedicle screw fusion for curves <100° that bend down to 50% on traction films, from T2-3 to the pelvis, using iliac screws. They advocate single-stage anterior release and posterior fusion for curves >120° with poor flexibility, or associated severe pelvic obliquity or sagittal deformity.
McCarthy et al. reviewed scoliosis in CP. They advocate proximal fixation to the upper thoracic spine (T1-2), and distal fixation to L4-5 (pelvic obliquity <15°) or to the pelvis (pelvic obliquity >15°). They add anterior release for larger, rigid curves that do not bend out to <60°, and in skeletally immature children.
Figures A and B are PA and lateral scoliosis radiographs demonstrating 75° of thoracolumbar scoliosis and severe pelvic obliquity, and progressive lumbar hyperlordosis. Illustrations A and B are PA and lateral scoliosis radiographs demonstrating correction of curve and pelvic obliquity using the Galveston Technique with segmental fixation utilizing sublaminar wires.
Incorrect Answers:
(SBQ12SP.26) Figure A is a lateral cervical spine radiograph of a 70-year-old female who presents with two months of posterior midline neck pain that is worse with motion. She has no history of trauma. She denies any symptoms of arm pain, gait instability, or dexterity problems with her hands. Physical exam of the lower extremities shows 2+ patellar reflexes and flexion of the great toe with a Babinski test. What should the patient be told regarding these radiographic findings?
Review
Topic
She requires surgical decompression to prevent progressive neurologic deterioration
85% of individuals over the age of 60 years of age demonstrate these findings
She is indicated for MRI to rule out cervical radiculopathy
She would benefit from modalities such as heat, cold, and transcutaneous electrical stimulation
She has <10% chance of having symptomatic improvement with non-operative treatment
The patient has symptomatic cervical spondylosis. She should be told that 85% of asymptomatic individuals over the age of 60 demonstrate these radiographic findings.
Cervical spondylosis is defined as age-related degenerative changes within the cervical spinal column. It can present as axial neck pain, cervical radiculopathy, cervical myelopathy, or as a combination of each. Radiographs demonstrate loss of disc height, arthrosis of the facet and uncovertebral joints, and endplate sclerosis. Imaging such as cervical spine radiographs and MRI should be interpreted carefully and correlated with clinical symptoms, as radiographic evidence of spondylosis is frequently seen in asymptomatic patients.
Boden et. al. reviewed the cervical MRI of 63 asymptomatic volunteers with no history of cervical spine symptoms. Of those, 19% were interpreted as having an abnormality. These findings included herniated nucleus pulposus, bulging disc, and foraminal stenosis. 60% of patients over 40 years demonstrated disc degeneration or narrowing at one level.
Rao et al. reviewed the presentation, pathogenesis, and management of cervical spondylosis. In this review, they report that 85% of patients older than 60 years demonstrate cervical spondylosis on radiography.
Figure A is a lateral cervical spine radiograph demonstrating spondylosis at multiple levels. There is disc height loss, facet sclerosis, and anterior osteophyte formation.
Incorrect Answers:

Question 84:

What molecules have been shown to promote fibrosis during muscle injury?

Options:

Insulin growth factor 1 (IGF-1)
Basic fibroblast growth factor (bFGF)
Transforming growth factor beta 1 (TGF-ß1)
Bone morphogenetic protein

Correct Answer: Transforming growth factor beta 1 (TGF-ß1)

Explanation:

Question 85:

Which of the following factors increases the risk of sciatic nerve injury in primary total hip arthroplasty (THA)?

Options:

Male gender
Anterolateral approach
Posterior superior quadrant acetabular screw placement
Osteonecrosis
Developmental dysplasia of the hip

Correct Answer: Developmental dysplasia of the hip

Explanation:

DISCUSSION: Injury to the sciatic nerve is a relatively rare but serious complication of THA. Dissection of the sciatic nerve is not typically done during primary THA, although the nerve can be identified during the surgical approach. An anterolateral approach to THA would not necessarily be associated with any greater incidence of sciatic nerve injury than other approaches. Screw fixation for the acetabular component is often a matter of surgeon preference. Provided that the anatomic safe zones for screw fixation (posterior inferior and posterior superior) are recognized, injury to the sciatic nerve from acetabular screws can be minimized. Restoration of anatomic length is important in primary THA. Overlengthening can result in sciatic nerve palsy. Developmental dysplasia of the hip can lead to a congenitally shortened extremity with concomitant congenital shortening of the associated neurovascular structures. Overlengthening of the extremity during THA for developmental dysplasia of the hip can lead to sciatic palsy. Osteonecrosis is not an associated risk factor for sciatic nerve palsy.
REFERENCES: DeHart MM, Riley LH Jr: Nerve injuries in total hip arthroplasty. J Am Acad Orthop Surg 1999;7:101-111.
Anas P, Felix B: Evaluation and prevention of postoperative complications, in Neurologic Injury in Revision THA. New York, NY, Springer Verlag, 1999, pp 361-371.

Question 86:

What clinical scenario is most consistent with the MR image of the L4-L5 disk level shown in Figure 14? Review Topic

Options:

Left L4 nerve root radiculopathy
Right L5 nerve root radiculopathy
Bowel and bladder dysfunction
Arachnoiditis
Symptomatic pseudomeningocele

Correct Answer: Left L4 nerve root radiculopathy

Explanation:

Question 87:

Based on the findings seen at C5-6 in Figure 30, the most likely deficit for this patient will be weakness of the

Options:

deltoid.
wrist flexor.
wrist extensor.
triceps.
grip.

Correct Answer: wrist extensor.

Explanation:

Question 88:

Options:

Pseudoparalysis secondary to fracture of the proximal humerus
Cervical myelomeningocele
Erb palsy
Arthrogryposis
Cerebral palsy and spastic hemiplegia

Correct Answer: Erb palsy

Explanation:

Question 89:

What is the average linear wear rate of a conventional, noncross-linked ultra-high molecular weight polyethylene liner used in total hip arthroplasty?

Options:

01 to 0.05 mm/yr
1 to 0.2 mm/yr
5 to 1 mm/yr
1 to 2 mm/yr
Greater than 2 mm/yr

Correct Answer: 1 to 0.2 mm/yr

Explanation:

Question 90:

Options:

Spanning external fixation of the radius
Open reduction and internal fixation of the radius with free fibular flap interposition
Open reduction and internal fixation of the radius with interposed strut allograft
Open reduction and internal fixation of the radius with massive cancellous allografting
Open reduction and internal fixation of the radius with massive cancellous autografting

Correct Answer: Open reduction and internal fixation of the radius with free fibular flap interposition

Explanation:

Question 91:

Options:

Medial ulnar collateral ligament (UCL) (anterior bundle)
Medial UCL (posterior bundle)
Lateral UCL
Annular ligament

Correct Answer: Lateral UCL

Explanation:

Question 92:

Options:

calcaneal osteotomy.
subtalar joint arthrodesis.
triple arthrodesis.
pantalar arthrodesis.
distraction bone block arthrodesis.

Correct Answer: subtalar joint arthrodesis.

Explanation:

DISCUSSION: The patient has posttraumatic subtalar joint arthrosis that developed following a calcaneal fracture. Because there is no hindfoot deformity, in situ subtalar joint arthrodesis is the treatment of choice. Calcaneal osteotomy or distraction bone block arthrodesis is beneficial in patients with severe talar dorsiflexion or malunion of the calcaneal body. Triple arthrodesis is not warranted without changes at the transverse tarsal joint, and typically even with injury into the calcaneocuboid joint, this joint is often asymptomatic. Pantalar arthrodesis is not indicated as the pathology is occurring at the subtalar joint and not in the ankle joint.
REFERENCES: Sanders R: Fractures and fracture-dislocations of the calcaneus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999,
pp 1422-1464.
Juliano TJ, Myerson MS: Fractures of the hindfoot, in Myerson MS (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 1297-1340.
Chandler JT, Bonar SK, Anderson RB, Davis WH: Results of in situ subtalar arthrodesis for late sequelae of calcaneus fractures. Foot Ankle Int 1999;20:18-24.

Question 93:

A 6-year-old girl is referred for the elbow injury seen in Figure 2. What is the most appropriate treatment?

Options:

Immobilization in a long arm cast for 3 weeks
Immobilization in a long arm cast for 8 weeks
Open reduction and immobilization in a long-arm cast for 3 weeks
Open reduction and internal fixation with smooth pins
Open reduction and internal fixation with a screw

Correct Answer: Open reduction and internal fixation with smooth pins

Explanation:

DISCUSSION: The patient has a displaced lateral condyle fracture; therefore, simple immobilization for 3 to 8 weeks is likely to result in malunion or nonunion. Closed reduction of such injuries is rarely successful. The fracture is unstable, so fixation is required after open reduction. Because the fixation must cross the physis, smooth pins are indicated for the skeletally immature elbow. Open reduction with fixation has been shown to reduce the risk of delayed union and malunion.
REFERENCES: Beaty JH, Kasser JR: The elbow: Physeal fractures, apophyseal injuries
of the distal humerus, avascular necrosis of the trochlea, and T-condylar fractures, in Beaty JH, Kasser JR (eds): Fractures in Children, ed 5. Philadelphia, PA, Lippincott Williams & Wilkins, 2001, pp 625-703.
Rutherford A: Fractures of the lateral humeral condyle in children. J Bone Joint Surg Am 1985;67:851-856.
Hasler CC, von Laer L: Prevention of growth disturbances after fractures of the lateral humeral condyle in children. J Pediatr Orthop B 2001;10:123-130.

Question 94:

Options:

first lordotic segment of the lumbar spine.
distal aspect of the curve as measured by the Cobb technique.
lower thoracic spine.
lower lumbar spine.
sacrum.

Correct Answer: first lordotic segment of the lumbar spine.

Explanation:

Question 95:

The radiographic finding in Figure 58 is indicative of what type of acetabular fracture?

Options:

Anterior column
Posterior column
Associated both column
Transverse
Associated transverse plus posterior wall

Correct Answer: Transverse

Explanation:

The radiographic image is an obturator oblique view of the left acetabulum and demonstrates a "spur" sign. It represents a spike of bone from the intact hemipelvis and no articular surface remains with the hemipelvis, which defines the associated both column fracture. The weight-bearing surface of the acetabulum is displaced with the femoral head. In all other patterns, at least part of the articular surface remains with the intact hemipelvis.
(SBQ12TR.58) A 35-year-old male was involved in a high speed motorcycle accident. He has a closed head injury, bilateral pulmonary contusions and splenic rupture. His orthopaedic injuries are shown in Figure A. He has a blood pressure of 90/50 mm Hg and a heart rate of 115, despite aggressive resuscitation. An arterial blood gas reveals that his blood lactate is 3.5 and base deficit is -6 mmol/L. Following successful closed reduction of the right hip in the operating room with a percutaneous inserted Schantz pin, what is the next most appropriate treatment for his orthopaedic injuries?
Review
Topic
Bilateral open reduction and internal fixation
Open reduction internal fixation on the right, reamed intramedullary nailing on the left
Temporizing external fixation on the right, open reduction and internal fixation on the left
Bilateral reamed intramedullary nailing
Bilateral temporizing external fixation
This patient presents with features of hemodynamic instability and a high injury severity score. The next most appropriate treatment would be temporizing external fixation bilaterally. This patient meets the criteria for damage control orthopaedics.
Damage control orthopaedics is an approach that contains and stabilizes orthopaedic injuries so that the patient's overall physiology does not undergo further inflammatory insult. As a result, external fixation of femoral shaft fracture and pelvic stabilization is an effective treatment under this strategy. Other indications include vascular injury and severe open fracture.
Pallister et al. reviewed the effects of surgical fracture fixation on the systemic inflammatory response to major trauma. They show that early stabilization of major long bone fractures is beneficial in reducing the incidence of acute respiratory distress syndrome and multiple organ failure. However, early fracture surgery increases the post-traumatic inflammatory response, which carries a higher complication rate compared to temporary fixation.
Tisherman et al. created clinical guidelines for the endpoints of resuscitation. Level I data found that standard hemodynamic parameters do not adequately quantify the degree of physiologic derangement in trauma patients. The initial base deficit, lactate level, or gastric pH should be used to stratify patients with regard to the need for ongoing fluid resuscitation.
Pape et al. retrospectively reviewed the impact of early total care vs. damage control orthopaedics in the treatment of femoral shaft fractures in polytrauma patients. They found a significantly higher incidence of acute respiratory distress syndrome (ARDS) with intramedullary nailing (15.1%) compared to external fixation (9.1%) when DCO subgroups were compared.
Figure A is a pelvic AP radiograph showing a right hip fracture-dislocation with an ipsilateral femoral shaft fracture. On the left side there is a displaced pertrochanteric hip fracture.
Incorrect Answers:

Question 96:

- Demyelination diseases as multiple sclerosis and Guillain-Barre $ create neurologic symptoms by

Options:

decreasing initiation of action potentials.
increasing action potential amplitude.
blocking the opening of gated sodium channels.
decreasing the number of functional motor units.
slowing or stopping action potential propagation through the axon.

Correct Answer: slowing or stopping action potential propagation through the axon.

Explanation:

Question 97:

Options:

Alcoholism
Drug abuse
Down syndrome
Diabetes mellitus
Idiopathic scoliosis

Correct Answer: Diabetes mellitus

Explanation:

DISCUSSION: The history, physical examination, and radiographic findings are consistent with type IV sacral agenesis or caudal regression syndrome. These children are born with no lumbar spine or sacrum. The T12 vertebra is often prominent posteriorly. Popliteal webbing and knee flexion contractures are common with this diagnosis. There is a higher incidence of this diagnosis when the mother has diabetes mellitus. Maternal drug abuse and alcoholism can produce phenotypically unique children but without the findings described here. Maternal idiopathic scoliosis is not associated with caudal regression syndrome.
REFERENCES: Chan BW, Chan KS, Koide T, et al: Maternal diabetes increases the risk of caudal regression caused by retinoic acid. Diabetes 2002;51:2811-2816.
Zaw W, Stone DG: Caudal regression syndrome in twin pregnancy with type II diabetes.
J Perinatol 2002;22:171-174.

Question 98:

Options:

Revision repair of subscapularis
Revision repair of infraspinatus
Latissimus dorsi transfer
Rotator interval release
Total shoulder arthroplasty

Correct Answer: Revision repair of subscapularis

Explanation:

Question 99:

Options:

Cervical C6-7 radiculopathy
Impingement
Rotator cuff tear
Brachial neuritis
Adhesive capsulitis

Correct Answer: Brachial neuritis

Explanation:

DISCUSSION: The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.
REFERENCES: Misamore GW, Lehman DE: Parsonage-Turner syndrome (acute brachial neuritis). J Bone Joint Surg Am 1996;78:1405-1408.
McCarty EC, Tsairis P, Warren RF: Brachial neuritis. Clin Orthop Relat Res 1999;368:37-43.

Question 100:

Options:

CT
MRI
Standing radiographs
Measurement of compartment pressures
Bone scan

Correct Answer: Standing radiographs

Explanation:

DISCUSSION: The patient has a suspected Lisfranc sprain based on the plantar ecchymosis. The first step in diagnosis is a dynamic radiographic study. This should include a physician-assisted midfoot stress examination or standing weight-bearing radiographs to evaluate for displacement. There is no evidence of compartment syndrome, and a bone scan, CT, and MRI are expensive tests that are not warranted.
REFERENCES: Early JS: Fractures and dislocations of the midfoot and forefoot, in Bucholz R, Heckman JD, Court-Brown CM (eds): Rockwood and Green’s Fractures in Adults. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp 2337-2400.
Hunt SA, Ropiak C, Tejwani NC: Lisfranc joint injuries: Diagnosis and treatment. Am J Orthop 2006;35:376-385.

Orthopedic Surgery Board Review MCQs: Arthroplasty, Ligament & Spine | Part 149

Orthopedic Board Review MCQs: Arthroplasty, Trauma & Elbow | Part 119

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