Orthopedic Board Prep MCQs: Arthroplasty & Foot

About This Board Review Set

This is Part 174 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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Two distinct learning modes are available:

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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 174

This module focuses heavily on: Arthroplasty, Foot, Hip, Knee.

Sample Questions from This Set

Sample Question 1: Ayear-oldwomanisscheduledtoundergorighttotalhiparthroplasty.Herpreoperativeradiographisshowninbelow.Toavoidincreasingthispatient’scombinedoffsetwhilemaintainingherleglength, what is the most appropriate surgical plan?...

Sample Question 2: ..First-line treatment recommendations include...

Sample Question 3: An 18-year-old man sustains a twisting injury to the left knee while playing football. An MRI scan is shown in Figure 48. What is the most likely diagnosis? Review Topic...

Sample Question 4: Figure 19 shows the radiograph of a 6-month-old infant who has limited hip motion. History reveals no complications during pregnancy or delivery. Examination reveals that hip abduction is 45 degrees in flexion bilaterally. The neurologic ex...

Sample Question 5: -The patient has no postsurgical complications and begins physical therapy rehabilitation. The boy and his parents stress they “want to get the therapy over with as fast as possible” to expedite his return to sports,and the surgeon and reha...

Why Active MCQ Practice Works

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

A year-old woman is scheduled to undergo right total hip arthroplasty. Her preoperative radiograph is shown in below. To avoid increasing this patient’s combined offset while maintaining her leg length, what is the most appropriate surgical plan?

Explanation

DISCUSSION:
The management of patients with proximal femoral deformity can be difficult. Appropriate implant selection and preoperative templating are critical. In this patient, it would be difficult to avoid increasing the combined offset by too much, which could contribute to the overtensioning of the soft tissues and trochanteric pain. By medializing the acetabular component (decreasing the combined offset), using a low offset femoral component or a cemented component placed more valgus (decreasing the combined offset), and making a longer neck cut (to avoid shortening of the lower extremity), restoration of the patient’s native offset and leg length can be achieved.

Question 2

..First-line treatment recommendations include

Explanation

RESPONSES FOR QUESTIONS 47 THROUGH 52
Ultrasound
MRI scan of the thigh
Chest CT scan and whole-body bone scan
Positron emission tomography (PET) scan
Presurgical radiation therapy
Marginal resection
Radical resection and postsurgical radiation
Transverse incision centered over the mass
Incision centered over the mass in line with long axis of limb
Sentinel node biopsy
Core needle biopsy
For each soft-tissue mass clinical scenario or question below, match the most appropriate next evaluation or treatment step listed above.

Question 3

An 18-year-old man sustains a twisting injury to the left knee while playing football. An MRI scan is shown in Figure 48. What is the most likely diagnosis? Review Topic

Explanation

The MRI scan shows a displaced, bucket-handle lateral meniscus tear. The sagittal view shows the typical "large anterior horn" sign, or "double meniscus" sign in which the displaced bucket-handle fragment appears just anterior to the native anterior horn of the lateral meniscus. The presence of the fibula on the sagittal view confirms this as the lateral compartment. The image is lateral and the cruciate ligaments are not visualized. The articular cartilage shown does not demonstrate an osteochondral lesion.

Question 4

Figure 19 shows the radiograph of a 6-month-old infant who has limited hip motion. History reveals no complications during pregnancy or delivery. Examination reveals that hip abduction is 45 degrees in flexion bilaterally. The neurologic examination is normal. What is the best course of action?

Explanation

DISCUSSION: Diminished hip abduction can occur in normal children and is not always associated with hip pathology; therefore, initial management should consist of observation.
REFERENCE: Castelein RM, Korte J: Limited hip abduction in the infant. J Pediatr Orthop 2001;21:668-670.

Question 5

-The patient has no postsurgical complications and begins physical therapy rehabilitation. The boy and his parents stress they “want to get the therapy over with as fast as possible” to expedite his return to sports,and the surgeon and rehabilitation team consider their request. Compared to nonaccelerated rehabilitation,patients who follow an early accelerated rehabilitation protocol experience

Explanation

DISCUSSION FOR QUESTIONS 44 AND 45
The Lachman test is the most sensitive examination for acute ACL injuries. ACL injury rates are higher in women than in men. This likely is attributable to anatomic differences (smaller notches, smaller ligaments, and different landing biomechanics). Lateral meniscal tears are more common than medial tears. The anterior drawer test is accentuated with 30 degrees of external rotation of the tibia. The MRI scan shows bone bruises consistent with an ACL tear. It is also always necessary to examine other structures of the knee in patients with ACL tears. All ligaments of the affected knee should be assessed.Lateral meniscal tears are frequently associated with ACL tears. Medial meniscal tears and posterolateral corner deficiency are also possible. Randomized clinical trials comparing an early accelerated vs nonaccelerated rehabilitation have demonstrated no significant differences in long-term results. These studies did not address timing of return to play with an early accelerated rehabilitation program. At 2 and 3 years postsurgically, there are no differences in laxity, number of graft failures, or KOOS scores.

Question 6

A 20-year-old woman with spastic hemiplegia is evaluated for function and hygiene issues with her right wrist. Her wrist has a resting posture of 90° of flexion and can be passively extended to 65° of flexion. Her fingers are flexed into her palm but can be passively extended with the wrist at 95°. What treatment is likely to provide the most durable result for improved hygiene, function, and cosmesis?

Explanation

EXPLANATION:
The patient has a static deformity of the wrist with a fixed flexion deformity of more than 45°. Soft-tissue procedures such as those referenced in options A and B would not be sufficient to address the degree of contracture. Additionally, Botulinum toxin injections would not provide relief for capsular contractures. Wrist arthrodesis combined with a proximal row carpectomy has been shown to provide a functional and cosmetic alternative for patients with severe wrist flexion contractures.

Question 7

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 8

The patient has weakness with elbow flexion and has numbness down the anterior lateral aspect of the forearm.

Explanation

DISCUSSION
The Latarjet procedure was initially described in 1959 as a modification of the Bristow procedure. It has been used as a primary procedure to address instability, but is used more commonly for patients with instability and glenoid bone loss. In 2000, Burkhart and associates reported a 67% failure rate of the Bankart procedure in patients with an inverted pear-shaped glenoid (glenoid bone loss) or an engaging Hill-Sachs lesion, with a suggestion that a bone graft procedure would be optimal in this population. Complications following the Latarjet procedure have been reported as high as 25%, with the majority attributable to nerve injury, recurrent instability, and arthritis. Many of these complications are likely secondary to surgical technique. A coracoid graft that is placed too laterally or with prominent screws will overhang the glenoid and lead to early degenerative glenohumeral arthritis. A coracoid graft placed too medially can lead to recurrent instability secondary to an ineffective subscapularis sling and bone block. A coracoid graft placed inferiorly indicates dissection close to the axillary nerve, which can place tension on the axillary nerve or cause injury from direct trauma. After harvesting the coracoid graft, the surgeon must find the musculocutaneous nerve as it enters the conjoint tendon on the medial surface about 5 cm distal to the coracoid. Excessive dissection or retraction can lead to musculocutaneous nerve palsy.

Question 9

A 13-year-old boy sustains a valgus stress injury to the knee while playing football, and he is unable to bear weight after the injury. Examination reveals tenderness medially superior to the joint line. The knee is held in flexion, and he has a large effusion and localized medial swelling. Plain radiographs show no obvious fracture. What is the next diagnostic step?

Explanation

DISCUSSION: In the skeletally mature individual, this mechanism of injury will often result in a sprain of the medial collateral ligament. In skeletally immature patients, the same mechanism can cause a fracture of the distal femoral physis. If the fracture is nondisplaced, the plain radiographs may show only soft-tissue swelling or effusion. While the MRI scan may show edema in the soft tissues on the medial side of the knee and even an abnormality of the physis, stress radiographs provide a quicker and less expensive means of making the diagnosis. Arthroscopy and arthrography would not be helpful in making the diagnosis. Arthroscopy may result in further displacement of the injury.
REFERENCES: Smith L: Concealed injury to the knee. J Bone Joint Surg Am 1962;44:1659-1660.
Beaty JH, Kumar A: Fractures about the knee in children. J Bone Joint Surg Am 1994;76:1870-1880.

Question 10

A decrease in alkaline phosphatase would most likely be manifest in which metabolic disorder?

Explanation

A decrease in tissue non-specific alkaline phosphatase (TNSALP) is found in hypophosphatasia.
TNSALP is found in osteoblasts and hydrolyzes inorganic phosphates, leading to an increase in serum phosphate levels, which helps to maintain physiologic levels. A decrease in this process impairs bone mineralization leading to rickets. In the perinatal period, hypophosphatasia and decreased mineralization leads to caput membraneceum, shortened limbs and respiratory failure. Childhood hypophosphatasia is marked by premature loss of deciduous teeth and rachitic deformities. Adult hypophosphatasia I is characterized by teeth and chest wall deformities (similar to adolescent hypophosphatasia) as well as recurrent metatarsal and femoral stress fractures.
Mornet reviewed hypophosphatasia and the alkaline phosphatase mutations. Screening for the 65 distinct mutation can aid in diagnosis and family counseling in severe forms.
Illustration A shows abnormal dentition found in hypophosphatasia. Illustration B shows widespread rachitic changes characteristic of hypophosphatasia.
Incorrect Answers:

Question 11

A previously healthy 13-year-old girl has had thigh pain for the past 3 weeks. The radiograph shown in Figure 47a reveals a lesion in the right femur. A bone scan and CT scan of the chest show no evidence of other lesions. A biopsy specimen is shown in Figure 47b. What is the most likely diagnosis?

Explanation

DISCUSSION: The patient has Langerhans cell histiocytosis that may be solitary (eosinophilic granuloma) or associated with systemic illness (Hand-Schuller-Christian disease and Letterer-Siwe disease). The solitary form of the disease, eosinophilic granuloma, typically affects patients in the first three decades of life. Radiographically, it is characterized as a well-defined, lytic, “punched out” intramedullary lesion. Histologically, two cell types, eosinophils and Langerhans cells, are seen. The Langerhans cells are seen as mononuclear histiocyte-like cells with oval nuclei with well-defined round or oval cytoplasm. A prominent nuclear groove can be seen in most of the nuclei (coffee bean nuclei). A mixture of inflammatory cells and lipid-laden foam cells with nuclear debris may be present as well. The lack of nuclear atypia and atypical mitoses excludes malignant conditions such as Ewing’s sarcoma, lymphoma of bone, and metastatic neuroblastoma. The lack of acute inflammatory cells excludes the diagnosis of osteomyelitis. The eosinophils have bi-lobed nuclei and granular eosinophilic cytoplasm.
REFERENCES: Dorfman H, Czerniak B: Bone Tumors. St Louis, MO, Mosby, 1988.
Mirra, JM: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea & Febiger, 1989.

Question 12

Figure 62 shows the radiograph of a 46-year-old man who has had increasing shoulder pain and diminishing motion over the last 10 years. Because his difficulties are severely impacting his quality of life, he is seeking advice and treatment options. Twenty five years ago, he underwent a shoulder stabilization procedure for recurrent shoulder dislocations. Examination reveals he can only elevate his arm to less than shoulder level and his external rotation is no more than 10 degrees. Management consisting of nonsteroidal anti-inflammatory drugs and intra-articular steroid injections has failed to provide relief. What is the most appropriate treatment recommendation? Review Topic

Explanation

The patient has classic "arthritis of dislocation." Procedures done years ago were designed to enhance shoulder stability by limiting external rotation. However, it is now understood that limiting external rotation results in significant alteration of joint mechanics and kinematics, thus leading to the development of osteoarthritis. The average age of patients who develop arthritis of dislocation is 45 years old. Despite the young age of these patients, total shoulder arthroplasty offers the most predictable improvement in pain and function. However, the patient must be made aware of the need to protect the arm from excessive loads to protect the glenoid implant. Because there is complete loss of articular cartilage and incongruent joint surfaces, there is no role for arthroscopic debridement and capsular release. Injections offer little, if any, chance of improvement with the prior history of nonresponse. Physical therapy predictably makes patients worse because loading the arthritic joint generates more pain. Reverse shoulder arthroplasty is reserved for elderly patients with severe rotator cuff deficiency. A humeral head arthroplasty, while potentially more ideal than a total shoulder arthroplasty because of glenoid concerns, would likely not offer pain relief in the face of the significant glenoid involvement and incongruity.

Question 13

Which of the following is the strongest contraindication to unicompartmental knee arthroplasty (UKA)?

Explanation

DISCUSSION: UKA prostheses cannot substitute for an absent ACL, and if arthroplasty is indicated, these patients should receive a total knee arthroplasty rather than a UKA. Age is not an absolute contraindication, and the procedure has been advocated for young patients as well as older patients if they meet the appropriate indications for an arthroplasty. Varus deformities of the mechanical axis of up to 10 degrees generally are not a contraindication to unicompartmental arthroplasty, as long as the knee can be properly balanced at the time of surgery. Modest chondromalacia of the patellofemoral joint, especially if asymptomatic, is not a contraindication to UKA.
REFERENCES: Lotke PA (ed): Knee Arthroplasty: Master Techniques in Orthopaedic Surgery. New York, NY, Raven Press, 1995, pp 275-293.
Insall JN, Windsor RE, Scott WN, et al (eds): Surgery of the Knee, ed 2. New York, NY, Churchill Livingstone, 1993, pp 805-814.
Tabor OB Jr, Tabor OB: Unicompartmental arthroplasty: A long-term follow-up study.

J Arthroplasty 1998;13:373-379.

Question 14

An 81-year-old man with severe low back pain reports right extensor hallucis longus and anterior tibialis weakness and difficulty urinating over the past 24 hours. He has a temperature of 101 degrees F (38.3 degrees C). MRI scans are shown in Figures 31a and 31b. Management should consist of

Explanation

DISCUSSION: An epidural abscess with neurologic deficit represents a medical and surgical emergency. The prognosis is related to the timeliness of diagnosis and treatment. Once identified, the primary treatment is surgical decompression of the abscess, followed by organism-specific antibiotics. In the absence of a significant anterior process such as diskitis or vertebral osteomyelitis, lumbar epidural abscesses generally can be drained through a posterior approach. Delayed stabilization usually is not required unless, in the course of decompression, removal of too much of the facets creates an instability; this is an uncommon occurrence.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 257-271.
Reihsaus E, Waldbaur H, Seeling W: Spinal epidural abscess: A meta-analysis of 915 patients. Neurosurg Rev 2000;23:175-204.

Question 15

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Explanation

Factor V Leiden is a disease caused by an abnormality of factor V in which a single amino acid substitution of glutamine for arginine in the protein C cleavage region leads to decreased inactivation of factor V and thus a greater tendency to form clots. More than half of all individuals with Factor V Leiden will develop deep venous thrombosis in the presence of a single additional risk factor such as long bone fracture or total joint arthroplasty.

Question 16

In patients with suspected hepatitis C, which of the following tests is commonly used to confirm the diagnosis after a positive ELISA screening test?

Explanation

DISCUSSION: The basic diagnostic test for hepatitis C (HCV) is detection of an antibody to epitopes on an enzyme-linked immunosorbent anti-HCV assay (ELISA). The currently used ELISA has high sensitivity (92%) and specificity (95%). False positives, however, still occur. The currently used supplemental test for HCV is strip immunoblot assay, which is based on detection of several HCV epitopes on nitrocellulose paper by antibody-capture techniques. Molecular amplification by PCR technology is very sensitive, but difficult to standardize and susceptible to contamination. Microarray and proteomics are relatively recent molecular techniques used for analysis of genes or proteins, respectively. A Northern blot is used to detect mRNA levels of specific genes but is not used in this situation.
REFERENCES: de Medina M, Schiff ER: Hepatitis C: Diagnostic assays. Semin Liver Dis 1995;15:33-40.
McGrory BJ, Kilby AE: Hepatitis C virus infection: Review and implications for the orthopedic surgeon. Am J Orthop 2000;29:261-266.

Question 17

What muscles are responsible for the most common deformity after antegrade intramedullary nailing for a subtrochanteric femur fracture?

Explanation

DISCUSSION: The most common deformity after antegrade nailing of a subtrochanteric femur fracture is varus and procurvatum (or flexion). This is caused by the hip abductors and iliopsoas pulling the proximal fragment into abduction and flexion, while the distal fragment is pulled into adduction from the adductors.
The reference by French et al is a review on 45 patients with subtrochanteric fractures treated with cephalomedullary interlocked nailing. Based on femoral neck-shaft angle, 61% of the fractures were reduced in at least 5º varus. The authors attributed this malalignment to failure to counteract muscle forces acting on the proximal fragment, combined with the adducted position of the distal femur during portal creation.
The reference by Ricci et al is a report of 403 femoral shaft fractures treated with intramedullary nailing. Patients with proximal femoral shaft fractures were found to have the highest incidence of malalignment. The most common deformity in this group was varus, followed by procurvatum (or flexion).

Question 18

Poor pre-injury cognitive function has been proven to increase mortality for which of the following injuries?

Explanation

DISCUSSION: Several studies have shown that only patient age and pre-injury functional independence measure scores were independent predictors of functional outcome after hip fracture. The other choices are less predictive than pre-injury functional status. The Soderqvist et al study showed that a Short Portable Mental Status Questionnaire score of <3 and male gender were associated with an increased mortality rate during the first twelve months. Moreover, patients with a score of <3 had a significantly worse outcome with regard to the ability to walk and to perform the activities of daily living. The referenced study by Holt et al is a prospective review of 1000 hip fractures and reported that pre-injury mobility to be the most significant determinant for post-operative survival. The referenced study by Cornwall et al found that six-month mortality was lowest for patients with nondisplaced femoral neck fractures (5.7%) and highest for patients with displaced femoral neck fractures (15.8%), but multivariate analysis only identified preinjury function as an independent predictor of mortality.

Question 19

Which of the following radiographic views best depicts a Hill-Sachs defect?

Explanation

DISCUSSION: The Stryker notch view best shows this type of defect. An outlet view helps evaluate acromial shape, a true AP shows joint space narrowing, a serendipity view evaluates the sternoclavicular joint, and a Zanca view helps evaluate the acromioclavicular joint. An internal rotation AP may also depict a Hill-Sachs defect.
REFERENCE: Rockwood CA, et al: X-ray evaluation of shoulder problems, in Rockwood CA, Matsen FA (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, vol 1, pp 178-207.

Question 20

A 32-year-old volleyball player has dull posterior shoulder pain. An examination reveals moderate external rotation weakness with his arm at his side, but normal strength on supraspinatus isolation. Deltoid and supraspinatus bulk appear normal, although there appears to be mild infraspinatus atrophy. Sensation is normal throughout the shoulder and shoulder girdle. What is the most likely diagnosis?

Explanation

DISCUSSION
This clinical scenario describes a patient with an isolated injury affecting the infraspinatus muscle. The anatomic location of such a lesion would be at the spinoglenoid notch, at which the suprascapular nerve may be compressed distal to its innervation of the supraspinatus but proximal to the infraspinatus innervation. A calcified transverse scapular ligament would also affect the suprascapular nerve but is proximal to the innervation of both muscles. Quadrilateral space syndrome would affect innervation of the deltoid (and teres minor). Parsonage-Turner syndrome is a more diffuse, and often severely painful, brachial plexus neuropathy.

Question 21

A 17-year-old high school soccer player sustains an anterior cruciate ligament (ACL) tear at the beginning of the season. An MRI scan confirms a complete ACL tear with no meniscal injuries. The patient plans an early return to play and would like to avoid surgery. Therefore, the patient and family should be advised that nonsurgical management consisting of rehabilitative exercises and the use of a functional knee brace will most likely result in

Explanation

DISCUSSION: While there are athletes who can function at a full level with an ACL tear, they are in the minority. As yet, there is no reliable way to predict the patients who will be able to compensate for the loss of the ACL. Studies have confirmed the risk of recurrent instability and meniscal injury in athletes with an ACL-deficient knee who participate in cutting sports. One study showed that only 12 of 43 patients who attempted rehabilitation and bracing were able to return successfully for the season. Another study showed that 17 of 31 athletes who were able to return to their sport sustained 23 meniscal tears because of recurrent instability.
REFERENCES: Shelton WR, Barrett GR, Dukes A: Early season anterior cruciate ligament tears: A treatment dilemma. Am J Sports Med 1997;25:656-658.
Snyder-Mackler L, Fitzgerald GK, Bartolozzi AR III, Ciccotti MG: The relationship between passive joint laxity and functional outcome after anterior cruciate ligament injury. Am J Sports Med 1997;25:191-195.

Question 22

A 35-year-old rock climber sustains an L1 burst fracture from a 30-foot fall while climbing. He sustained no other fractures or serious injuries. He is neurologically intact and has minimal posterior tenderness without increased spinous process separation on examination. Radiographs reveal kyphosis of 20 degrees between T12 and L2 with 30% vertebral height loss. A CT scan shows 55% canal compromise. What is the most appropriate management? Review Topic

Explanation

Wood and associates have shown that the use of a TLSO or a body jacket was equally effective as surgery for the treatment of thoracolumbar burst fractures without neurologic deficit. The only difference in any of the measured parameters (including pain, functional outcome, residual canal compromise, and kyphosis) was a decreased complication rate in the nonsurgical group compared with the surgical group. The maximum time to mobilization in the nonsurgical group was 5 days.

Question 23

A 17-year-old javelin thrower reports medial-sided elbow pain and diminished grip strength while throwing. He has decreased sensation in the little and ring fingers of his throwing hand only while throwing. The sensory deficits resolve at rest. Examination of the elbow reveals no instability and full motion. He has a positive Tinel’s sign over the cubital tunnel and a positive elbow flexion test. Radiographs are normal. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient’s symptoms and examination findings are consistent with ulnar neuritis/cubital tunnel syndrome, most probably exacerbated by javelin throwing. The first step includes rest and extension splinting. Surgical intervention should only be considered after failure of nonsurgical management.
REFERENCES: Posner MA: Compressive neuropathies of the ulnar nerve at the elbow and wrist. Instr Course Lect 2000;49:305-317.
Omer GE, Spinner M, Van Beek AL (eds): Management of Peripheral Nerve Problems, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 65-69.

Question 24

Figures 31a and 31b show the radiograph and MRI scan of an otherwise normal 3-month-old infant who has a spinal deformity. MRI reveals no intraspinal anomalies. What is the next step in management?

Explanation

DISCUSSION: Congenital scoliosis in an infant warrants evaluation of the renal, cardiac, and neurologic systems because frequently there is concurrent pathology. Progression in this instance is possible but not certain; therefore, progression must be documented prior to any surgical intervention. Close observation with serial radiographs every 4 to 6 months is appropriate. All of the surgical options listed may be reasonable choices in the future, but cardiac evaluation is the most important issue at this time.
REFERENCES: Basu PS, Elsebaie H, Noordeen MH: Congenital spinal deformity:

A comprehensive assessment at presentation. Spine 2002;27:2255-2259.
Hedequist D, Emans J: Congenital scoliosis. J Am Acad Orthop Surg 2004;12:266-275.

Question 25

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule?

Explanation

DISCUSSION: Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.
REFERENCES: Dreese J, D’Alessandro D: Posterior capsulorrhaphy through infraspinatus split for posterior instability. Tech Shoulder Elbow Surg 2005;6:199-207.
Shaffer BS, Conway J, Jobe FW, et al: Infraspinatus muscle-splitting incision in posterior shoulder surgery: An anatomic and electromyographic study. Am J Sports Med 1994;22:113-120.
Fuchs B, Jost B, Gerber C: Posterior-inferior capsular shift for the treatment of recurrent voluntary posterior subluxation of the shoulder. J Bone Joint Surg Am 2000;82:16-25.

Question 26

A 57-year-old woman experiences pain 1 year after total knee arthroplasty (TKA). She reports sharp anterior pain and a painful catching sensation that is aggravated by rising from a chair or climbing stairs. Physical examination reveals a mild effusion and a range of motion of 2° to 130°, with patellar crepitus. The symptoms are reproduced by resisted knee extension. Radiographs show a well-aligned posterior-stabilized TKA without evidence of component loosening. What is the most likely cause of this patient's pain?

Explanation

DISCUSSION:
Patellar clunk syndrome is caused by the development of a fibrous nodule on the posterior aspect of the quadriceps tendon at its insertion into the patella. It causes a painful catching sensation when the extensor mechanism traverses over the trochlear notch as the knee extends from 45° of flexion to 30° from full extension. It characteristically occurs in posterior stabilized total knee arthroplasties and appears to be related to femoral component design. The syndrome can usually be prevented by excising the residual synovial fold just proximal to the patella. Flexion gap instability can also cause a painful total knee arthroplasty but is less common in posterior stabilized implants. Femoral component malrotation can cause pain attributable to a flexion gap imbalance or patellar tracking problems. Polyethylene wear would be unlikely after just 1 year. Patellar clunk syndrome can usually be addressed successfully with arthroscopic synovectomy. Recurrence is uncommon. Physical therapy may help to strengthen the quadriceps following synovectomy but would not resolve the clunk syndrome symptoms. Femoral or tibial insert revision is not indicated if patellar clunk syndrome is the only problem resulting in a painful
total knee arthroplasty.

Question 27

A 10-month-old boy has an untreated developmental hip dislocation.

Explanation

DISCUSSION
Early radiographic findings of avascular necrosis (AVN) of the hip include sclerosis and a subchondral lucency. A common presentation of Legg-Calve-Perthes disease (idiopathic pediatric hip AVN) is intermittent pain in the thigh, groin, or knee with an examination localizing to the hip; a Trendelenburg gait or sign; and painful, restricted passive hip range of motion. AVN also may be observed in association with a slipped capital femoral epiphysis (SCFE). AVN risk is highest in the setting of an unstable SCFE (10%-60%); risk is 0% to 1.4% when the SCFE is stable. A multicenter review of the modified Dunn procedure for treatment of unstable SCFE noted an AVN rate of 26%.
The most common deformity associated with SCFE is proximal femoral varus, flexion, and external rotation leading to an abnormal femoral head-neck junction offset. This causes a loss of passive hip flexion and internal rotation and the phenomenon of obligate external
rotation with flexion. The residual deformity frequently results in femoroacetabular impingement. Labral tears also are associated with cam impingement secondary to underlying osseous abnormalities including abnormal femoral head-neck junction offset.
Endocrinopathies potentially are associated with SCFE because of hormone-related physeal changes and subsequent mechanical insufficiency of the proximal femoral physis. With renal osteodystrophy, the physeal widening results from secondary hyperparathyroidism and progressive proximal femoral deformity may develop. Optimal medical management of hyperparathyroidism is essential. Surgical stabilization via in situ fixation of the proximal femur is indicated when SCFE is diagnosed.
The proximal femoral epiphysis secondary ossification center commonly appears between the ages of 4 and 7 months. In the setting of developmental hip dislocation, the appearance of the secondary ossification center is commonly delayed. After closed or open reduction of developmental dysplasia of the hip, failure of the femoral head ossific nucleus to appear within 12 months following the reduction is a sign of proximal femoral growth disturbance and AVN.

Question 28

Figures 9a and 9b show the radiographs of a 75-year-old man who underwent a revision total knee arthroplasty with a long-stemmed tibial component. In rehabilitation, he reports fullness and tenderness in the proximal medial leg (at the knee). The strategy that would best limit this postoperative problem is use of

Explanation

DISCUSSION: The problem with this reconstruction is the medial protrusion of the base plate. The use of a base plate with an offset stem can prevent the protrusion and thus the impingement and pain. Allograft bone or smoothing the outline with cement would be just as prominent and likely to cause pain. An ingrowth surface may improve soft-tissue attachment but would still leave the implant protruding medially and likely to cause pain. A nonstemmed tibial base plate would lead to less medial protrusion but at the expense of a smaller area for load carriage on the proximal tibia.
REFERENCE: Gustke K: Cemented tibial stems are not requisite in revision. Orthopedics 2004;27:991-992.

Question 29

A 34-year- woman has pain at the base of the thumb that worsens é pinching activities. Nonsurgical treatment has failed to provide relief. Examination reveals that the basilar joint is hypermobile, tender and painful when stressed. A radiograph of the trapeziometacarpal joint shows normal contour with widening when compared with the opposite side. Management should consist of

Explanation

Painful instability of the thumb carpometacarpal (CMC) joint as manifested by “idiopathic hypermobility of the basal joint is not uncommon, particularly in women, and would seem to be a significant factor in producing the arthrosis that so frequently afflicts this joint.” “Extra-articular ligament reconstruction to stabilize the thumb carpometacarpal (CMC) (basal) joint by routing a portion of the flexor carpi radialis (FCR) through the base of the thumb metacarpal … is recommended only for patients in stage I and stage II disease (i.e., patient’s having zero to only slight cartilage attrition). With 95 % of stage I and stage II patients having achieved and maintained good or excellent results, (restoration of stability, pain reduction and possibly retarding joint degeneration) … we feel the procedure has proved predictable and durable. Despite limited success in patients with significant articular deterioration (stage III and stage IV), we do not recommend ligament reconstruction alone in such cases. Instead we would recommend articular resurfacing or implant arthroplasty that would depend on the number of trapezium surfaces involved.”

Question 30

A neurologic injury at T11-L2 with loss of bowel and bladder control is best described as what syndrome?

Explanation

DISCUSSION: Conus medullaris syndrome describes isolated loss of bowel and bladder function, usually at T12-L1 but can include T11-L2. In central cord syndrome, lower extremity motor function is better than upper extremity function. Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss. Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss. In anterior cord syndrome, the lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as motor function.
REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3. Philadelphia, PA, WB Saunders, 1992, Chapter 31.
Weisberg LA: Neurologic localization: Lesions below foramen magnum, in Weisberg LA, Strub RL, Garcia CA (eds): Adult Neurology, ed 2. St. Louis, MO, Mosby, 1993.

Question 31

Which of the following conditions is most likely inherited as an autosomal dominant trait?

Explanation

Postaxial polydactyly involves polydactyly of the little finger, preaxial polydactyly usually involves the thumb or the index finger. Postaxial polydactyly is further divided into Type A, in which the well formed extra digit artier with the fifth or an extra metacarpal and Type B, a small extra digit that is poorly formed and often is little more than a skin tag. Postaxial polydactyly is inherited as an autosomal dominant trait with marked penetrance.

Question 32

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

Explanation

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

Question 33

What is the most common maxillofacial/dental injury in ice hockey?

Explanation

DISCUSSION: Lahti and associates reported that the most common dental injury in a study of 479 injured ice hockey players was a noncomplicated crown fracture, which accounted for 43.5% of all maxillofacial/ dental injuries. The most common cause of injury was a blow from an ice hockey stick. As a cause of injury, the stick was approximately three times as common in games as in training, and only 10% of injured players wore some sort of protective guard. A tooth avulsion is a partial or complete
displacement of the tooth from aleveolar support. A crown fracture is an incomplete loss or fracture of the tooth enamel without loss of the tooth. The other injuries (mandible fracture, lip laceration, tooth
avulsion, and temporomandibular contusion) occur but are not nearly as common.
REFERENCES: Lahti H, Sane J, Ylipaavalniemi P: Dental injuries in ice hockey games and training. Med Sci Sports Exerc 2002;34:400-402.
Minkoff J, Stecker S, Varlotta GP, et al: Ice hockey, in Fu FH, Stone DA (eds): Sports Injuries, ed 2.
Philadelphia, PA, 2001, pp 516-517.

Question 34

Figure 35 is the radiograph of a 37-year-old woman who began having right forefoot pain about 4 weeks ago after increasing her daily running mileage. She denies any specific injury. Upon examination she has tenderness over the medial forefoot with mild swelling. In addition to her activity level, what is the primary etiology of the radiograph finding?

Explanation

DISCUSSION
Stress fractures are the result of physiological bone response to increased stress. Increased stress on bone triggers an increase in remodeling, which begins with resorption of bone at the site of stress. Ongoing stress can overwhelm bone strength, resulting in a fracture. In the foot this most commonly is seen in the second metatarsal at the junction of the middle and distal thirds. Contributing factors to increased loading of the second metatarsal include hallux valgus (decreased hallux loading transfers to the second metatarsal head), hallux rigidus (offloading of the hallux attributable to pain increases second metatarsal loading), and a long second metatarsal (increased duration of contact during push-off in the stance phase).
RECOMMENDED READINGS
Shindle MK, Endo Y, Warren RF, Lane JM, Helfet DL, Schwartz EN, Ellis SJ.
Stress fractures about the tibia, foot, and ankle. J Am Acad Orthop Surg. 2012 Mar;20(3):167-

Question 35

A 17-year-old African American high school football player is in the afternoon session of an August “2-a-day” practice. He tells his trainer he is experiencing weakness, dizziness, and nausea. The ambient temperature is 31°C with a relative humidity of 70%. An examination by the team trainer reveals a body temperature of 39°C and headache, chills, confusion, and disorientation. What is the most likely diagnosis?

Explanation

DISCUSSION
Heat exhaustion and heatstroke are both forms of heat illness during which the body is unable to self-regulate internal temperature. The hallmarks of heatstroke are altered mental status and/or core temperature higher than 40°C. Heat exhaustion may be marked by nausea, vomiting, headache, dizziness, chills, and excessive sweating, but there are no mental status
changes. In heatstroke, sweating can often slow or cease as dysregulation worsens. Simple dehydration would not result in mental status changes or elevated core temperature. Sickle-cell crisis is marked by extreme pain, with location depending on the site of crisis. Four main patterns are common: bone, chest, abdominal, or joint crises. Sickle-cell crisis can be precipitated by dehydration, although it also can occur as a result of cold exposure.

Question 36

Compared with surgically treated patients, patients with extra-articular distal third humeral shaft fractures that are treated nonsurgically with functional bracing can be expected to show which of the following findings?

Explanation

In a retrospective review of patients with extra-articular distal humeral shaft fractures treated surgically versus nonsurgically, the authors found that the amount of motion loss was not different between the treatment groups. Of 21 patients in the nonsurgical group, one lost 20 degrees of extension, one lost 30 degrees of extension, and one patient lost 15 degrees of flexion. Of the 19 patients in the surgical group, two patients lost 5 degrees of extension, and one each lost 10, 15, and 20 degrees of extension, respectively. One patient lost 5 degrees of flexion and one lost 15 degrees of flexion. The average loss of motion in the surgical group was 3 degrees, compared with 6 degrees in the nonsurgical group, but this difference was not significant. One hundred percent of the nonsurgically treated fractures healed. Both groups of patients regained shoulder motion within 10 degrees of normal. In the nonsurgically treated group, 10 healed with less than 10 degrees of malalignment, 6 healed with 11 to 20 degrees of malalignment, and three healed with greater than 30 degrees of malalignment, but the authors did not report any functional problems due to these deformities.

Question 37

Which of the following muscles has dual innervation?

Explanation

DISCUSSION: The brachialis muscle typically receives dual innervation. The major portion is innervated by the musculocutaneous nerve. Its inferolateral portion is innervated by the radial nerve. The others listed have single innervation. The anterior approach to the humerus, which requires splitting of the brachialis, capitalizes on this dual innervation.
REFERENCE: Mahakkanukrauh P, Somsarp V: Dual innervation of the brachialis muscle.

Clin Anat 2002;15:206-209.

Question 38

Which of the following postoperative rehabilitation techniques causes minimal rotator cuff muscle activation? Review Topic

Explanation

Electromyography (EMG) studies have shown that the rotator cuff is least active with passive range of motion and hence this is allowed early in most postoperative rotator cuff rehabilitation protocols. Active forward flexion, active-assisted motion, and isometric strengthening all cause activation of the rotator cuff muscles (as measured by EMG) and therefore should be introduced later in rehabilitation when the repair can withstand these forces. Whereas some authors have felt that pulley-assisted range of motion exercises are safe, EMG analysis has demonstrated that these exercises do cause activation of the rotator cuff musculature and probably should be avoided early in the rehabilitation protocol.

Question 39

What is the usual mechanism of injury for the fracture shown in Figures 49a and 49b?

Explanation

Figures 49a and 49b show a severely comminuted, displaced fracture of the distal tibial metaphysis with intra-articular extension, i.e. pilon fx, or the so-called “distal tibial explosion fracture.” According to the article by Kellam JF and Waddell JP, there are “two mechanisms that can cause this fracture, a rotational pronation dorsiflexion force, and an axial compression force with the foot in either neutral or dorsiflexion at the moment of impact. Because of these mechanisms of injury, two fracture patterns were observed in the series of patients reported. The rotational pattern results in several large metaphyseal fragments, and usually a fibular fracture of a short oblique type above the level of the ankle joint…The second and unfortunately the more common fracture pattern is caused by a severe axial compression force which causes marked comminution of the distal tibial metaphysis, loss of bone substance due to impaction, superior migration of the talus, and loss of the ankle cartilage space.”

Question 40

A 50-year-old man fell from a ladder onto his left shoulder and sustained the injury shown in the radiographs in Figures 71a and 71b. He underwent surgery with repair of the coracoclavicular ligaments and deltotrapezial fascia with coracoclavicular screw placement. Which of the following statements regarding postoperative complications is most accurate? Review Topic

Explanation

Whereas pain and functional disturbance may persist with nonsurgical management, the lack of articular surface contact prevents arthritic symptoms from developing. Cartilage injury caused by trauma and any persistent joint incongruity following repair would contribute to posttraumatic arthritis. Pinning across the acromioclavicular joint has a high incidence of hardware migration and potential catastrophic consequences. Most cases of lost fixation of coracoclavicular screws are at the level of the thread purchase in the coracoid. Routine hardware removal at 8 to 12 weeks is recommended to avoid screw breakage because of natural movement between the clavicle and scapula. The axillary nerve passes around the inferior edge of the subscapularis and is anatomically distant to the the coracoid. The musculocutaneous nerve would have the closest anatomic position to the coracoid.

Question 41

Figure 1 shows the radiograph obtained from a 67-year-old woman who has progressive wrist pain. She undergoes a salvage motion-sparing surgery that relies on the intact cartilage of the capitate head. It is necessary to preserve what structure during this procedure?

Explanation

EXPLANATION:
The radioscaphocapitate ligament must be preserved in cases of proximal row carpectomy or scaphoidectomy with four-corner fusion. Failure to do so can result in ulnar translocation of the carpus. The attachment of the long radiolunate ligament to the lunate is compromised in proximal row carpectomy, although it is left intact in scaphoidectomy with four-corner fusion. Preservation of the dorsal radiocarpal ligament through a limited arthrotomy is advocated by Ozyurekoglu and Turker as a method of preserving the blood and nerve supply of the carpus, but this technique has not been proven to be required. The authors did cut through the dorsal intercarpal ligament in their exposure.

Question 42

Radiographs of a 15-year-old girl with knee pain reveal a radiopaque lesion of the distal femoral metaphysis and epiphysis with a small associated soft-tissue mass. A biopsy specimen shows osteoid and pleomorphic cells with multiple mitotic figures. Staging studies show no other sites of disease. Treatment should consist of

Explanation

DISCUSSION: Based on the location and extent of the tumor, most patients are candidates for limb salvage surgery. The patient has an osteosarcoma; therefore, the treatment of choice is preoperative chemotherapy, wide resection, and reconstruction. There is no difference in survival rates between patients who undergo limb salvage surgery and those who undergo amputation. Curettage and placement of methylmethacrylate is used to treat benign lesions of bone and would not be appropriate in this patient.
REFERENCE: Simon MA, Springfield DS, et al: Common Malignant Bone Tumors: Osteosarcoma. Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 265-274.

Question 43

A year-old man reports symptomatic medial knee pain that has become progressively worse during the past year. MRI reveals a complex, posterior horn medial meniscus tear with associated medial lateral and patellofemoral cartilage defects. Radiographs reveal medial joint space narrowing and osteophytes in the other compartments. What treatment is most likely to provide long-term, durable relief of symptoms?

Explanation

DISCUSSION:
Total knee replacement is a well-established surgery for diffuse, symptomatic osteoarthritis of the knee joint, and its efficacy has been shown in many studies. According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee, arthroscopy in the setting of existing osteoarthritis is efficacious for relieving the signs and symptoms of a torn meniscus but not for osteoarthritis. Likewise, in young and active patients, clinical outcomes show improvement after realignment osteotomy for single- compartment osteoarthritis. Unicondylar knee replacement is not indicated for tricompartmental disease
of the knee.

Question 44

A 45-year-old distance runner has a hyaluronic acid injection to his knee because of degenerative arthritis. He immediately develops a severe rash and a systemic hypersensitivity reaction. This patient most likely is also allergic to which of the following?

Explanation

DISCUSSION: Preparations of hyaluronic acid can be divided into low and high molecular weight compounds. Contraindications to intra-articular hyaluronic acid include joint or skin infection, overlying skin disease, and allergies to chicken or egg products if using a preparation derived from rooster comb.
REFERENCES: Gloyscen DN, Gillespie MJ, Schenek RC: The effects of medication in sports injuries, in DeLee JC, Drez D Jr, Miller MD (eds): Orthopedic Sports Medicine: Principles and Practice, ed 2.
Philadelphia, PA, WB Saunders, 2003, vol 1, pp 121-124.
Schenck RC Jr: New approaches to the treatment of osteoarthritis: Oral glucosamine and chondroitin sulfate. Instr Course Lect 2000;49:491-494.

Question 45

Which factor increases the success rate associated with all-inside lateral meniscal repair?

Explanation

DISCUSSION
Decreased patient age, neutral alignment, and a concomitant ACL tear are associated with improved success rates of meniscal repair. Meniscus tears on the contralateral side of the knee and articular cartilage defects are not associated with improved healing rates.
RESPONSES FOR QUESTIONS 5 THROUGH 6
Physical therapy and a home exercise program
Corticosteroid injection
Arthroscopic debridement
Microfracture
Osteochondral autograft transplantation (OAT)
Match the treatment above with the clinical scenario below

Question 46

Figure 91 is the radiograph of a 20-year-old man who kicked a door while intoxicated. At the emergency department, his leg is placed into a long-leg cast. After 2 hours, he reports increasing pain, numbness, and tingling in his toes. What is the most appropriate initial treatment?

Explanation

Observation only
Referral to physiotherapy
MRI spine and hip
Total hip arthroplasty
Intramedullary femoral nail
This osteoporotic female patient is presenting with subtrochanteric lateral cortical thickening and hip pain. This is consistent with an insufficiency fracture of the femur secondary to use of bisphosphonate medication for treatment of osteoporosis. The most appropriate treatment would be intramedullary femoral nail fixation.
Bisphosphonate medications have been shown to be associated with atypical (subtrochanteric) femur fractures. These patients often have prodromal hip pain and lateral cortical thickening on radiographs prior to fracture. In addition, there has shown to be a significantly increased risk of fracture in the presence of the “dreaded black line” that occurs at the site of thickening.
Lenart et al. examined a case series of patients using bisphosphonates for the treatment of osteoporosis. They identified 15 postmenopausal women who had been receiving alendronate for a mean (±SD) of 5.4±2.7 years and who presented with atypical low-energy fractures. Cortical thickening was present in the contralateral femur in all the patients with this pattern.
Goh et al. retrospectively reviewed patients who had presented with a low-energy subtrochanteric fractures. They identified 13 women of whom nine were on long-term alendronate therapy. Five of these nine patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur.
Figure A shows a right hip radiograph with subtrochanteric lateral cortical thickening. There is mild arthritic changes in the hip. Illustration A shows a bone scan and radiographs of subtrochanteric lateral cortical thickening that resulted in fracture.
Incorrect Answers

Question 47

What artery provides the only direct vascularizaton to both the intraneural and extraneural blood supply of the ulnar nerve just proximal to the cubital tunnel?

Explanation

DISCUSSION: The superior ulnar collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries provide consistent vascular supply to the ulnar nerve. This supply is segmental in nature. No identifiable direct anastomosis is seen between the superior ulnar collateral and the posterior ulnar recurrent arteries. The inferior ulnar collateral artery provides the only direct vascularization to the nerve and is located in the region just proximal to the cubital tunnel. The segmental nature of the blood supply to the ulnar nerve underscores the importance of its preservation during transposition.
REFERENCE: Yamaguchi K, Sweet FA, Bindra R, et al: The extraneural and intraneural arterial anatomy of the ulnar nerve at the elbow. J Shoulder Elbow Surg 1999;8:17-21.

Question 48

Which of the following best describes the relationship of the anterior tibial artery and dorsalis pedis artery to the extensor hallucis longus (EHL) tendon as they progress from the level of the ankle to the dorsum of the foot?

Explanation

DISCUSSION: At the ankle level, the anterior tibial artery lies medial to the EHL tendon. The artery becomes the dorsalis pedis after crossing onto the dorsum of the foot. At this point, the artery lies lateral to the tendon.
REFERENCES: Resch S: Functional anatomy and topography of the foot and ankle, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 1, pp 25-49.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993.

Question 49

What is the most common physical finding in myelopathic patients? Review Topic

Explanation

The Hoffman sign is the most common finding, occurring in 80% of myelopathic patients, and it is more common with increasing severity of the myelopathy. The prevalence of hyperreflexia has been shown to be no different from the prevalence in individuals without myelopathy. Sustained clonus and Babinski signs have been shown to occur in only one third of the patients with myelopathy.

Question 50

When treating a proximal tibia fracture, the surgeon decides to (1) use blocking screws in the proximal fragment, and (2) pick the intramedullary nail based on the location of the Herzog curve. Which of the following combinations will best prevent the classic deformity associated with this fracture?

Explanation

Proximal tibial fractures develop an apex anterior (procurvatum) and valgus malalignment. Blocking (poller) screws should be placed in the concavity of the deformity, thus posterior and lateral to the nail. The Herzog curve should be proximal to the fracture site.
Up to 58% of proximal tibial fractures are malaligned. Malalignment arises because the nail fits loosely in the wide metaphyses and cannot control alignment. Without close fit of the nail at the fracture site, the nail will not align the fracture independent of a stable reduction and careful nail path. Blocking screws serve to reduce the size of the proximal metaphyseal canal and guide final nail passage.
Stinner et al. discuss strategies in proximal tibial fracture nailing. They describe an accurate starting point (using the twin peaks AP view or fibular bisector AP view, and flat plateau lateral view). They emphasize fracture reduction prior to reaming and implant placement.
Hiesterman reviewed nailing of extra-articular proximal tibial fractures. Techniques described include blocking screws, unicortical plating, using a universal distractor, nailing in flexion/locking in extension, semiextended nailing (including percutaneous suprapatellar quads-splitting approaches), multiple proximal interlocking screws (>=3).
Illustration A shows placement of a coronal blocking screw. Illustration B shows placement of a sagittal blocking screw. Illustration C shows the effect of the Herzog curve. A more distal Herzog curve leads to a "wedge" effect and fracture displacement whereas a proximal Herzog curve contains the fracture. The "wedge" effect occurs as the nail is seated and impinges on the posterior cortex of the distal segment accentuating an apex anterior deformity because of the effective widening of the nail above the bend and posterior force on the distal segment to match the nail shape.
Incorrect Answers:

Question 51

Figure 27 shows the radiograph of a 26-year-old man who sustained a closed head injury and a closed elbow dislocation 6 weeks ago. Examination reveals 65 degrees to 115 degrees of flexion, and intensive physical therapy has resulted in no improvement. A decision regarding the timing of surgical correction of the contracture should be based on

Explanation

DISCUSSION: The patient has heterotopic ossification, a more common finding in patients who have sustained head injuries. Treatment will require removal of the heterotopic bone and anterior and posterior capsulectomies. The main concern about timing is the possible recurrence of heterotopic bone. While an extended wait was once thought necessary, this is no longer true. The timing is based on the time since injury and evidence of bone maturation on plain radiographs. A sharp marginal demarcation of the new bone and a trabecular pattern within it are usually present 3 to 6 months after onset, indicating that it is safe to proceed with surgical excision. It is not necessary to wait more than 6 months. Bone scan results are not good indicators because they may remain “hot” for long periods of time. The levels of alkaline phosphatase and serum calcium-phosphorus product do not need to be measured.
REFERENCE: Norris TR (ed): Orthopaedic Knowledge Update: Shoulder and Elbow. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 325-335.

Question 52

A “p value” of 4% (p=0.04) indicates that the

Explanation

The paper cited is an excellent review in detail about confidence intervals including the mathematical equations.
The p value is the probability that the chance selection of patients might suggest a difference in treatment that was not real. Only with a small p value are we willing to believe that the observed difference in treatment is very likely real and not simply due to chance.
The confidence interval provides a measure of the magnitude of the possible difference between two groups of patients, regardless of whether or not the p value was small. This makes the confidence interval more informative than the p value when different treatments are compared. This is much beyond the scope of this review.

Question 53

Which of the following statements best describes the instantaneous axis of rotation (IAR) for the functional spinal unit? Review Topic

Explanation

The instantaneous axis of rotation is the axis about which each vertebral segment rotates, but is theoretical depending on how it is defined, and varies depending on multiple factors. It is not a fixed point but can move depending on the position of the spine, and it is affected by degenerative conditions, fractures, injuries, and other anatomic changes of the spine. There are three axes of movement with 6 degrees of freedom (rotation and translation movements about each axis).

Question 54

Figure 131 is the abdominal radiograph of a 70-year-old man who experiences nausea and abdominal tightness 48 hours after undergoing left total knee arthroplasty. An examination reveals severe abdominal distension and markedly decreased bowel sounds. Insertion of a nasogastric tube does not relieve abdominal tightness. What is the best next step?

Explanation

DISCUSSION
The abdominal radiograph reveals an acute colonic pseudo-obstruction. It is associated with parenteral narcotic use and hypokalemia. Initial treatment is insertion of a nasograstric tube, discontinuation of parenteral narcotics, and correction of electrolyte imbalances. If a pseudo-obstruction is not relieved, colonoscopy should be performed.

Question 55

What type of cementless femoral fixation results in the highest rate of distal femoral osteolysis?

Explanation

DISCUSSION: Despite the relatively few problems with porous-coated cementless stems, stress shielding and thigh pain do occur. One design feature of proximally coated stems that has been associated with a higher incidence of distal osteolysis is the presence of noncircumferential proximal porous coating. Tapered, modular with sleeve, and hydroxyapatite proximally porous-coated stems have all performed well. Fully porous-coated straight stems have a high survivorship rate as well.
REFERENCES: Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 175-180.
Koval KJ (ed): Orthopaedic Knowledge Update 7. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 417-451.
Emerson RH Jr, Sanders SB, Head WC, Higgins L: Effect of circumferential plasma-spray porous coating on the rate of femoral osteolysis after total hip arthroplasty. J Bone Joint Surg Am 1999;81:1291-1298.

Question 56

A 47-year-old man has an acute swollen, red, painful first metatarsophalangeal joint. He denies any history of similar symptoms. What is the first step in evaluation?

Explanation

DISCUSSION: The patient’s symptoms are typical for gouty arthropathy, and the diagnosis can only be confirmed with aspiration and visualization of the crystals. A concomitant infection also must be ruled out; therefore, it is important to obtain a cell count and culture. Colchicine may have a role in gouty management, but the diagnosis must be confirmed. Allopurinol is not effective in acute gouty arthropathy. Measurement of serum uric acid levels is often not helpful in making a definitive diagnosis. Steroid injections should be deferred until cell count and culture results indicate no accompanying infection.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 172-173.
Jahss MH: Disorders of the Foot and Ankle, ed 2. Philadelphia, PA, WB Saunders, 1991,

pp 1712-1718.

Question 57

A 22-year-old man who sustained a Gustilo-Anderson grade IIIC open fracture of the right tibia and fibula was treated with an immediate open transtibial amputation. After two serial debridements, he underwent wound closure with a posterior myocutaneous soft-tissue flap. What is the preferred method of early rehabilitation?

Explanation

DISCUSSION: There is no evidence that early weight bearing enhances ultimate rehabilitation. At the other extreme, weight bearing should not be delayed for a prolonged period of time. In a young, healthy individual, the rigid plaster dressing appears to be the safest method of protecting the wound during the early postoperative period. If the wound appears to be secure, early partial weight bearing can be safely initiated.
REFERENCES: Burgess EM, Romano RL, Zettl JH: The Management of Lower Extremity Amputations. Washington, DC, US Government Printing Office, 1969, also at: www.prs-research.org.
Smith DG, McFarland LV, Sangeorzan BJ, et al: Postoperative dressing and management strategies for transtibial amputations: A critical review. J Rehabil Res Dev 2003;40:213-224.

Question 58

Figure 37 shows a coronal T2-weighted MRI scan. What is the name of the labeled torn structure?

Explanation

DISCUSSION: The labeled structure is the LCL, and it is avulsed from the lateral humeral epicondyle. This is the most common site of injury for the LCL. The biceps and brachialis tendon insertions are not well visualized in this section. The MCL and flexor/pronator origin

are intact.
REFERENCES: Potter HG, Weiland AJ, Schatz JA, et al: Posterolateral rotatory instability of the elbow: Usefulness of MR imaging in diagnosis. Radiology 1997;204:185-189.
King JC, Spencer EE: Lateral ligamentous instability: Techniques of repair and reconstruction. Techniques in Orthopaedics 2000;8:93-104.

Question 59

A 23-year-old woman has had vague left knee pain for the past 6 months. A radiograph and CT scan are shown in Figures 50a and 50b. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiographic appearance of the lesion emanating from the posterior cortex of the left distal femur is consistent with a surface bone-producing lesion; therefore, the most likely diagnosis is a parosteal osteosarcoma. In an osteochondroma, the cortex and medullary cavity of the lesion are in continuity with that of the native bone. A dedifferentiated chondrosarcoma has histologic components of a high-grade sarcoma plus a benign or low-grade malignant cartilage tumor. Tumoral calcinosis is characterized by amorphous calcium in the soft tissues and does not emanate from the bone itself. While often confused with parosteal osteosarcoma, myositis ossificans is usually more mature at the periphery of the lesion rather than the center. In addition, myositis ossificans does not involve the underlying cortex but remains separate from the bone.
REFERENCES: Unni KK: Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases, ed 5. Philadelphia, PA, Lippincott-Raven, 1996, pp 185-196.
Okada K, Frassica FJ, Sim FH, Beabout JW, Bond JR, Unni KK: Parosteal osteosarcoma. A clinicopathological study. J Bone Joint Surg Am 1994;76:366-378.

Question 60

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

Explanation

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

Question 61

A 5-month-old girl with arthrogryposis has a limb-length discrepancy. Examination and radiographs reveal unilateral hip dislocation. Management should consist of

Explanation

DISCUSSION: In this age group of patients with arthrogryposis, open reduction through a medial approach is generally recommended. Open reduction through an anterior approach is reserved for patients in which a medial approach has failed or for older patients who require simultaneous femoral shortening and/or pelvic osteotomy. Closed treatment of unilateral hip dislocation in association with arthrogryposis is rarely successful. In bilateral hip dislocation associated with arthrogrypsis, the consensus is that the hips are best left unreduced because of the difficulty in obtaining excellent clinical and radiographic results bilaterally.
REFERENCES: Staheli LT, Chew DE, Elliot JS, Mosca VS: Management of hip dislocations in children with arthrogryposis. J Pediatr Orthop 1987;7:681-685.
Szoke G, Staheli LT, Jaffe K, Hall JG: Medial-approach open reduction of hip dislocation in amyoplasia-type arthrogryposis. J Pediatr Orthop 1996;16:127-130.
Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996.

Question 62

What factor is associated with a high risk of developing pseudotumors after metal-on-metal hip resurfacing?

Explanation

The recent experience of a large clinical cohort revealed the most likely risk factors as being female gender, age younger than 40, small components, and a diagnosis of hip dysplasia causing osteoarthritis. Failure was least likely among men and after procedures involving larger components. These data have prompted some authors to caution against using metal-on-metal hip resurfacing in women and to primarily target candidates who are men younger than age 50. Small components may be more prone to failure because of malpositioning and edge loading, which have been noted to be more common in dysplasia cases.

Question 63

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

Explanation

DISCUSSION: Patient safety and prevention of medical errors is a major focus of recent national advocacy groups. Analysis has shown that the most common sentinel event in spine surgery is surgery on the wrong level. Therefore, it is recommended that every patient have the surgical site signed, the level of surgery marked intraoperatively, and a radiograph taken. Surgery on the wrong level is most likely to occur in single-level decompressive procedures.
REFERENCES: Wong DA, Watters WC III: To err is human: Quality and safety issues in spine care. Spine 2007;32:S2-S8.
Wong DA: Spinal surgery and patient safety: A systems approach. J Am Acad Orthop Surg 2006;14:226-232.

Question 64

The parents of a 3-year-old girl who has had pain and swelling in the right ankle for the past 3 months now report that she has a limp and that the right knee and both ankles are painful and swollen. The limp and difficulty walking are most severe in the morning when the child first gets out of bed and are also more severe after extended walking. The parents deny fever, chills, weight loss, or night pain. Examination shows mild swelling and slightly restricted motion of the right knee and both ankles but is otherwise normal. In addition to initiation of treatment, the child should be referred to which of the following specialists?

Explanation

DISCUSSION: Pauciarticular juvenile rheumatoid arthritis (JRA) is the most common subgroup of JRA. It typically presents between the ages of 2 to 4 years with a mild swelling of one to four joints. Girls are affected four times more often than boys. The ankle and knee are commonly involved, and limping is typically worse in the morning and after extended activity. The diagnosis of pauciarticular JRA is typically one of exclusion because laboratory studies, including erythrocyte sedimentation rate and rheumatoid factor, are usually within normal limits. Pauciarticular JRA has the highest incidence of chronic uveitis, and in the subgroup with elevated antinuclear antibody (ANA) titers, the incidence is 75%. In JRA, uveitis usually occurs after the onset of synovitis but may precede the joint symptoms. At the early stage of uveitis, the patient is asymptomatic. If the eye condition is not detected and treated, progressive loss of vision may occur. Orthopaedic surgeons may be instrumental in making the diagnosis of pauciarticular JRA. Pauciarticular JRA is not associated with conditions that require input from the other specialists.
REFERENCES: Carey TP: Inflammatory arthritides: Juvenile rheumatoid arthritis, seronegative spondyloarthropathies, transient synovitis, hemophilic arthropathy, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics. St Louis, MO, Mosby, 2002, pp 1315-1321.
Wright D: Juvenile idiopathic arthritis, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001,

pp 427-458.

Question 65

A 42-year-old female with chronic discogenic back pain undergoes lumbar spine surgery via retroperitoneal approach. Figure A is the postoperative radiograph of her lumbar spine. Six weeks after the surgery the patient develops worsening low back pain. You obtain a radiograph of her lumbar spine, pictured in Figure B. What is the next best step in management? Review Topic

Explanation

This patient has a failed lumbar total disc replacement (TDR) with anterior dislocation of the polyethylene inlay and requires revision surgery, either revision arthroplasty or anterior interbody fusion, via retroperitoneal approach.
Management of failed TDR is dictated by (1) patient symptoms and (2) radiographic implant position. Asymptomatic patients with implant subsidence without extrusion can be managed with close observation. Patients with persistent symptomatic back pain relating to facet joint or implant microinstability in the setting of an otherwise well-positioned TDR can be treated with posterior stabilization alone. Symptomatic patients with unacceptable implant position (i.e. complete dislodgement, fracture) require either revision arthroplasty or conversion to arthrodesis (anterior +/-
posterior).
Harrison et al. authored a report detailing a case of failed L5-S1 TDR with anterior dislocation of the polyethylene inlay and bilateral L5 pars fractures noted 2 weeks postoperatively. It is unclear whether the pars defect was missed following previous microdiscectomy, acquired during instrumentation, or acquired postoperatively due to abnormal endplate forces during rehabilitation. The patient underwent removal of TDR components and revision to anterior arthrodesis followed by percutaneous fixation of the bilateral L5 pars fractures.
Patel et al. published a review of the literature regarding revision lumbar TDR. Retroperitoneal revision procedures are complicated by higher risk of injury to vascular structures (16.7% versus 3.6% at primary surgery) and urogenital structures due to adhesions. Revision surgery should only be performed by surgeons familiar with the retroperitoneal approach to the spine. Alternative surgical approaches, such as the far lateral approach, should be considered to access the anterior spine at L4-L5 and above.
Madigan et al. reviewed the management of lumbar degenerative disc disease (DDD). They state that TDR is a motion-sparing surgical option designed to temper the problem of adjacent-segment disease. They report that long-term studies are limited, but point out that several short-term comparisons between TDR and ALIF show equivalent improvement in pain and function, equal complication rate, shorter hospitalization and lower rate of reoperation in the TDR group.
Figure A is a lateral radiograph of the lumbar spine showing L5-S1 total disc replacement. Figure B is a lateral radiograph of the lumbar spine showing L5-S1 total disc replacement with anterior dislocation of the polyethylene inlay.
Incorrect Responses:

Question 66

Which of the following vertebrae has the smallest pedicle isthmic width in a nondeformity patient?

Explanation

DISCUSSION: The smallest pedicle isthmic width is at L1, whereas T12 has the largest pedicle width in the upper lumbar and lower thoracic spine. Although smaller in diameter than T12, both T10 and T11 have larger pedicle widths than L1.
REFERENCE: Ofiram E, Polly DW, Gilbert TJ Jr, et al: Is it safe to place pedicle screws in the lower thoracic spine than in the upper lumbar spine? Spine 2007;32:49-54.

Question 67

A 47-year-old woman underwent a distal chevron bunionectomy 2 months ago. Her postoperative recovery had been uneventful until 1 week ago. She now has new onset pain and dorsal swelling in the area of the third metatarsal. A radiograph is shown in Figure 27. What is the most likely diagnosis?

Explanation

DISCUSSION: Based on findings of a sudden increase in pain with associated swelling, the most likely diagnosis is a stress fracture. The initial radiographic findings usually will be negative. Morton’s neuroma and transfer metatarsalgia are not associated with swelling. Metatarsophalangeal synovitis usually involves the second metatarsophalangeal joint. Freiberg’s infraction is seen clearly on a radiograph.
REFERENCE: Boden BP, Osbahr DC: High risk stress fractures: Evaluation and treatment. J Am Acad Orthop Surg 2000;8:344-353.

Question 68

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

Explanation

DISCUSSION: Achieving stability in chronic locked posterior dislocations of the shoulder remains a difficult challenge. Intraoperative measures include decreased humeral retroversion, anterior releases, and posterior capsular tightening. Postoperative rehabilitation is of equal importance. Immobilization in an external rotation brace (10 degrees to 15 degrees) with the arm at the side for 4 to 6 weeks is recommended to decrease tension in the posterior capsule. When passive range-of-motion exercises are instituted, they should be performed in the plane of the scapula to avoid stress posteriorly. Internal rotation and supine elevation should be avoided for similar reasons.
REFERENCES: Hawkins RJ, Neer CS II, Pianta RM, Mendoza FX: Locked posterior dislocation of the shoulder. J Bone Joint Surg Am 1987;69:9-18.
Loebenberg MI, Cuomo F: The treatment of chronic anterior and posterior dislocations of the glenohumeral joint and associated articular surface defects. Orthop Clin North Am 2000;31:23-24.

Question 69

Where is the watershed zone for tarsal navicular vascularity?

Explanation

DISCUSSION: The central one third has been established as the watershed zone by angiographic studies, and has been borne out in clinical conditions involving the navicular, such as stress fractures and osteonecrosis. These findings account for the susceptibility to injury at this level.
REFERENCES: Nunley JA, Pfeffer GB, Sanders RW, et al (eds): Advanced Reconstruction: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004,

pp 239-242.
Sarrafian SK: Anatomy of the Foot and Ankle. Philadelphia, PA, JB Lippincott, 1983,

pp 299-302.

Question 70

A 62-year-old patient is seen for routine follow-up after undergoing cementless total hip arthroplasty 2 years ago. The patient reports limited range of motion that severely affects daily activities. A radiograph is shown in Figure 51. Management should now consist of

Explanation

DISCUSSION: The patient has symptomatic postoperative heterotopic ossification after total hip arthroplasty. Postoperative prophylactic treatments include nonsteroidal anti-inflammatory drugs (usually indomethacin) or low-dose irradiation. The heterotopic ossification shown here is quite mature; therefore, nonsurgical management will not be successful. Surgical excision of grade III or IV heterotopic ossification should be followed with postoperative irradiation to minimize the chances of recurrence.
REFERENCES: Ayers DC, Evarts CM, Parkinson JR: The prevention of heterotopic ossification in high-risk patients by low-dose radiation therapy after total hip arthroplasty. J Bone Joint Surg Am 1986;68:1423-1430.
Healy WL, Lo TC, DeSimone AA, et al: Single-dose irradiation for the prevention of heterotopic ossification after total hip arthroplasty: A comparison of doses of five hundred and fifty and seven hundred centigray. J Bone Joint Surg Am 1995;77:590-595.

Question 71

Figure 4 shows the MRI scan of a patient who has had bilateral leg pain, weakness, diffuse numbness, and urinary retention for the past week. Examination reveals that motor strength is diffusely decreased, although it may be secondary to pain. The patient is numb throughout both legs, and reflexes in the lower extremities are absent. Rectal examination shows decreased tone, but voluntary tightening is present. Management should consist of

Explanation

DISCUSSION: The patient has a cauda equina syndrome. The fact that he has decreased rectal tone and urinary retention suggests the need for urgent surgery. Patients who are left untreated will have a poor prognosis for return of function. Although most patients who have insidious onset of symptoms with urinary retention will regain normal motor function following decompression, nearly one third will continue to have abnormal voiding patterns or sexual dysfunction of varying degrees.
REFERENCES: Kostuik JP, Harrington I, Alexander D, Rand W, Evans D: Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am 1986;68:386-391.
Wisneski RJ, Garfin SR, Rothman RH, Lutz GE: Lumbar disk disease, in Herkowitz HN, Garfin SR, Balderston RA, et al (eds): The Spine, ed 4. Philadelphia, PA,WB Saunders, 1992, vol 1,

pp 613-679.

Question 72

A cord-like middle glenohumeral ligament and absent anterosuperior labrum complex can be a normal anatomic capsulolabral variant. If this normal variation is repaired during arthroscopy, it will cause Review Topic

Explanation

If the Buford complex is mistakenly reattached to the neck of the glenoid, severe painful restriction of external rotation will occur.

Question 73

Which of the following is considered the most appropriate indication for conversion of a hip fusion to total hip arthroplasty?

Explanation

DISCUSSION: Hip fusion provides successful long-term results (20 to 30 years). The usual mode of failure is symptomatic arthrosis of the lower back, contralateral hip, or the ipsilateral knee. Disabling low back pain is the best indication for conversion and responds well to the procedure. Degenerative changes in the other joints do not respond as well and frequently require replacement arthroplasty. Restoration of limb length is not predictable after conversion to hip replacement.
REFERENCES: Santore RF: Hip reconstruction: Nonarthroplasty, in Callaghan JJ, Dennis DA, Paprosky WG, Rosenberg AG (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, pp 109-115.
Callaghan JJ, Brand RA, Pedersen DR: Hip arthrodesis: A long-term follow-up. J Bone Joint Surg Am 1985;67:1328-1335.

Question 74

Bridge plating of the olecranon is MOST appropriate in which of the following clinical scenarios?

Explanation

DISCUSSION: Bridge plating is most appropriately used for fixation of comminuted fractures which are not able to be fixed anatomically. Of the choices listed above, this would be most appropriate in a comminuted fracture in a 45-year-old male. In contrast, literature shows that severely comminuted, osteoporotic low-demand elderly are best treated with olecranon fracture excision and triceps advancement when possible.
Bailey et al looked at the outcome of plate fixation of olecranon fractures. They concluded that plate fixation is effective for displaced olecranon fractures and leads to good functional outcome. There were low incidence of complications, although 20% did have removal of hardware due to irritation.
Hak et al reviewed the fixation options for olecranon fractures. In their review, they state that comminuted olecranon fractures can be treated by limited-contact dynamic-compression plates. They also supported the use of supplemental bone graft to support comminuted depressed articular fragments. Fragment excision and triceps advancement is appropriate in selected cases in which open reduction seems unlikely to be successful, such as in osteoporotic elderly patients with severely comminuted fractures.

Question 75

Which of the following classes of antibiotics works by binding to the 30S-ribosomal subunit?

Explanation

Aminoglycosides work by inhibiting peptide elongation by binding to the 30S-ribosomal subunit.
Aminoglycosides are among the oldest classes of antibiotics. They are act by binding to the 30S ribosomal subunit and are considered bactericidal. Due to their effectiveness on Gram-negative bacteria they are often used in conjunction with cephalosporins for treatment of open fractures. Care must be taken when using aminoglycosides due to their potential nephrotoxicity and ototoxicity.
Mader et al. present an instructional course lecture reviewing common antibiotics and their mechanisms of action. For aminoglycosides, they comment that their primary use is for aerobic Gram-negative organisms, particularly enterobacter species and P. aeruginosa. Aminoglycosides have realtively poor activity against Gram-positive organisms and should not be used for staph or strep species.
Illustration A is a diagram showing the mechanism of action of different antibiotics. Incorrect Answers:

Question 76

The posterior cord of the brachial plexus terminates into what two main branches?

Explanation

DISCUSSION: The posterior cord of the brachial plexus terminates into the radial and axillary nerves. The lateral cord terminates in branches to the musculocutaneous and the lateral root of the median nerve. The medial cord terminates in branches to the ulnar and medial roots of the median nerve.
REFERENCE: Hollinshead WH: Anatomy for Surgeons: The Back and Limbs, ed 3. Philadelphia, PA, Harper and Row, 1982, pp 228-236.

Question 77

A 57-year-old woman experiences pain 1 year after total knee arthroplasty (TKA). She reports sharp anterior pain and a painful catching sensation that is aggravated by rising from a chair or climbing stairs. Physical examination reveals a mild effusion and a range of motion of 2° to 130°, with patellar crepitus. The symptoms are reproduced by resisted knee extension. Radiographs show a well-aligned posterior- stabilized TKA without evidence of component loosening. What is the most likely cause of this patient's pain?

Explanation

Question 78

What is the most significant benefit of percutaneous transforaminal lumbar interbody fusion (TLIF) vs open posterior lumbar interbody fusion (PLIF)?

Explanation

DISCUSSION
Humphreys and associates in a retrospective review of TLIF vs PLIF found fusion rates, surgical time, and length of hospital stay were similar with both procedures. The only benefits associated with TLIF were less blood loss and preservation of the paraspinal muscle sleeve. Manos and associates in a cadaver study found no difference in the volume of disk material evacuated or the area of endplate exposed in either procedure.
RECOMMENDED READINGS
Humphreys SC, Hodges SD, Patwardhan AG, Eck JC, Murphy RB, Covington LA. Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine (Phila Pa 1976). 2001 Mar 1;26(5):567-71. PubMed PMID: 11242386. View Abstract at PubMed
Manos R, Sukovich W, Weistroffer J: Transforaminal lumbar interbody fusion: Minimally invasive versus open disc excision and endplate preparation. Presented at the 12th International Meeting of Advanced Spine Techniques, Banff, Alberta, Canada, July 7-9, 2005.

Question 79

Following irrigation and debridement, what is the preferred method of fixation for a displaced open tibia fracture with a 16-cm clean wound?

Explanation

Unreamed nails disrupt the diaphyseal cortical circulation by about 30% as compared to reamed nails that disrupt the circulation about 70%. This aids in healing of open fractures. Because of the smaller diameter used with unreamed nails they are weaker and therefore are made solid without cannulation for added strength. Unreamed nails have a lower rate of infection than plates. External fixators are used for periarticular fractures with compromised soft tissue and when the foreign body might attribute to higher rates of infection like a nail or plate.

Question 80

Benign Ethnic Neutropenia is more common in males.

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:
The perioperative use of which medication has been shown to increase the risk of post-operative infection following orthopaedic procedures in patients with rheumatoid arthritis (RA)?
Naproxen
Leflunomide
Sulfasalazine
Etanercept
Aspirin
Of the medications listed, only etanercept has been shown to increase the risk of post- operative infection following orthopaedic procedures in patients with RA.
Etanercept is a TNF-alpha antagonist with a short half-life that is administered once or twice weekly in patients with RA. Since TNF-alpha plays a central role in the pathogenesis of RA and is instrumental in causing joint destruction, the inhibition of this molecule has shown excellent results in controlling disease. The most powered study on TNF-alpha inhibitor use in the perioperative period following an orthopaedic procedures demonstrated a significant increase in
post-operative infection.
Howe et al. review the medical management of patients with RA who underwent orthopaedic procedures. They state that while there is conflicting information regarding TNF-alpha antagonists, they recommend holding them prior to major orthopaedic interventions.
Giles et al. review 91 patients with rheumatoid arthritis who underwent an orthopaedic procedure. They found TNF-alpha inhibitor therapy to be significantly associated with the development of a serious postoperative infection (p=.041)
Perhala et al. review 61 patients with RA who were treated with methotrexate during the perioperative period surrounding a total joint arthroplasty. They
failed to find a significant increase in complications in this patient group, stating the perioperative use of methotrexate does not affect wound healing or increase the likelihood of periprosthetic infection.
Illustration A shows the site of action of TNA-alpha inhibitors in the RA pathway.
Incorrect Answers:
Communication breakdown is the leading cause of which of the following?
Delayed diagnoses
Medication errors
Surgical site infections
1 and 2
All of the above
Communication failures are the leading cause of wrong side surgeries, medication errors and diagnostic delays.
Poor communication sets up environments in which medical errors can take place. Per the Joint Commission, medical errors may be the among the top 10 causes of death in the United States. Establishing open lines of communication is critical to reduce the risk of error and enhance patient safety.
Gandhi et al. designed a framework to study missed or delayed diagnoses and their causes. The most significant factors contributing to errors were poor handoffs, failures in judgment, failures in memory and failures in knowledge.
O’Daniel et al. review the importance of professional communication and collaborative team efforts. They note that patient safety is at risk when poor communication is in place. The leading cause for medication errors, treatment delays and wrong-site surgeries is communication failure.
Illustration A shows the leading causes of death in the United States. This includes “preventable errors” as a cause.
Incorrect Answers:
treatment, medication errors and wrong side surgery
Which of the following is true regarding osteoprotegerin (OPG)?
It is secreted by osteoclasts
It increases bone resorption
Binds to prostoglandin E2 before stimulating osteoclasts
Osteoprotegerin knock-out mice develop osteopetrosis
Binds to and sequesters RANKL
Osteoprotegerin is a decoy receptor for RANKL. Binding to RANKL causes decreased production of osteoclasts by inhibiting the differentiation of osteoclast precursors.
Bone resporption/remodeling is a complex process regulated by a large variety of molecules. Molecules that have shown to inhibit osteoclasts include OPG, calcitonin, estrogen, TGF-B, and IL-10. Corticosteroids have been shown to decrease production of OPG, thereby enhancing osteoclast formation and longevity. Prolia, or denosumab, is a newly approved drug used to treat osteoporosis and has a mechanism of action similar to osteoprotegerin
(inhibits binding of RANKL to RANK).
Boyle et al. review osteoclast differentiation and activation. The authors state that targeted disruption of OPG causes increased osteoclastogenesis and/or activation resulting in osteopenia.
Illustration A shows how OPG binds to RANKL inhibiting the stimulation of osteoclasts.
Incorrect Answers:
A 55-year-old woman has T-score -2.0 at the femoral neck. According to the World Health Organization Fracture Risk Assessment Tool (FRAX), she has a ten- year probability of sustaining a hip fracture of 1.5% and a ten-year probability of sustaining a major osteoporotic fracture of 8.9%. Which of the following statements is true regarding her antiresorptive therapy management?
Antiresorptive therapy should be started based on her T-score
Antiresorptive therapy should be started based on her risk of hip fracture alone
Antiresorptive therapy should be started based on her risk of major osteoporotic fracture alone
Antiresorptive therapy should not be started
Antiresorptive therapy should be started based on her risks of both hip fracture and major osteoporotic fracture
This patient has osteopenia. Assessment by FRAX shows that ten-year risk of hip fracture is less than 3% and her ten-year risk of major osteoporosis- related fracture is less than 20%. Therefore, antiresorptive therapy is not indicated at this time.
According to the 2008 National Osteoporosis Foundation guidelines, pharmacologic treatment for osteoporosis should be considered if patients are
postmenopausal women or men greater than 50 years old AND meet one of the following criteria: (1) they have a prior hip or vertebral fracture, (2) they have a T score -2.5 or less at the femoral neck or spine, (3) they have a T score between -1.0 and -2.5 at the femoral neck or spine AND a 10-year risk of hip fracture greater than 3% or 10-year risk of major osteoporosis-related fracture greater than 20%.
FRAX (World Health Organization Fracture Risk Assessment Tool) calculates
year risk of fracture based on the following variables: age, sex, race, height, weight, BMI, history of fragility fracture, parental history of hip fracture, use of oral glucocorticoids, secondary osteoporosis and alcohol use to calculate 10-year risk of fracture.
Unnanuntana et al. reviewed the assessment of fracture risk. Besides FRAX score and T-score, they discussed biochemical markers of bone formation and resorption, which are useful for monitoring the efficacy of antiresorptive / anabolic therapy, and may help identify patients at high risk for fracture.
Ekman et al. reviewed the role of the orthopaedic surgeon in minimizing mortality and morbidity associated with fragility fractures. The surgeon should consider prescribing appropriate medications, physical therapy, assessing fall risk and preventing falls and changing lifestyle factors (exercise, smoking and alcohol).
Illustration A shows the FRAX online tool (http://www.shef.ac.uk/FRAX/tool.aspx?country= =9).Illustration B shows the clinical risk factors considered in FRAX calculation.
Incorrect Answers:
A 32-year-old runner sustains a trimalleolar left ankle fracture. She undergoes open reduction and internal fixation and is kept non- weightbearing after surgery. At 2 months, what changes will occur in the articular cartilage of both her knees as a result of her current weightbearing regimen?
Cartilage thickening in the left (ipsilateral) knee and no change in cartilage thickness in the right (contralateral) knee
Cartilage thinning in both knees
Cartilage thinning in the left (ipsilateral) knee and no change in cartilage thickness in the right (contralateral) knee
Cartilage thinning in the left (ipsilateral) knee and increased cartilage thickness in the right (contralateral) knee
Increased cartilage thickness in both knees
After a period of off-loading, the off-loaded limb will experience cartilage thinning. The contralateral limb will not demonstrate any cartilage changes.
Physiologic loading of cartilage increases proteoglycan synthesis and cell proliferation and is chondroprotective. Joint immobilization leads to cartilage thinning, tissue softening, and reduced proteoglycan content, leading to cartilage erosion. Joint overuse leads to cartilage damage (in vitro only).
Hinterwimmer et al. examined cartilage atrophy after partial load bearing
using quantitative MRI. They found cartilage thinning in all knee compartments (greatest thinning, medial tibia; least thinning, patella). There was no change in cartilage morphology in the contralateral knee.
Sun reviewed the relationship between mechanical loading and cartilage degeneration. In OA, cartilage breakdown occurs at the articular surface, and is then fueled by synovial proteases and cytokines. In RA, synovial cells and macrophages are the source of degradative enzymes and incite cartilage destruction.
Milward-Sadler et al. examined mRNA levels following mechanical stimulation in normal and osteoarthritic chondrocytes. Normal chondrocytes showed increased aggrecan mRNA and decreased matrix metalloproteinase 3 (MMP-3) mRNA after stimulation. This
chondroprotective response was absent in osteoarthritic chondrocytes.
Illustration A shows pro- and anti-inflammatory mechanisms of mechanical loading on chondrocytes. Underloading and overloading induce cartilage damage through pathways involving the upregulation of MMPs and ADAMTSs (ADAMTS, a disintegrin and metalloproteinase with thrombospondin motifs, or aggrecanase). Physiological loading blocks these increases.
Incorrect Answers:
A morbidly obese 40-year-old man is scheduled to undergo hemilaminectomy for resection of an painful osteoid osteoma of the T6 lamina. He is positioned prone on a Jackson table and localization is performed with intraoperative fluoroscopy prior to the start of the case. At close to the end of the case, intraoperative frozen section reveals only normal bone fragment from the resected lamina. A probe is placed and a cross-table lateral radiograph reveals that the T7 lamina was resected instead of T6. At this point, the surgeon should
do all of the following EXCEPT
Complete the surgery
Abort the case and obtain further imaging
Apologize to the patient and family
Formally document the error in the operative report
Inform the patient and family immediately after the operation
Fluoroscopic localization of the correct thoracic vertebra can be difficult in the obese
patient. Upon detection of wrong level surgery, he should not abort the case. Rather, he should perform the desired procedure at the correct site, and advise the patient and family upon completion.
Adverse events are inevitable. The correct action following wrong-site surgery is to perform the desired procedure at the correct site followed by frank and honest communication with the patient/family. Open, honest communication favorably affects patient behavior, health outcomes, patient satisfaction, and often reduces the incidence of medical professional liability actions. The
discussion should include a disclosure of known facts and an explanation as to the likely cause, as well as ongoing treatment, follow up care, and prognosis.
The AAOS Information Statement about Wrong Site Surgery identifies 3 treatment steps following discovery of an error during surgery under general anesthesia: Return the patient to his preoperative condition, perform the correct procedure at the correct site, and advise the patient and family of what occurred and the likely consequences, if any, of the wrong- site surgery.
The AAOS Information Statement on Communicating Adverse Events states that the surgeon has an ethical and professional obligation to disclose the error to the patient and/or family. Disclosure should include what happened, why it happened, health implications, and what measures are being instituted to prevent recurrences.
Incorrect Answers:
All of the following are Standards of Professionalism relating to interactions with industry for practicing orthopaedic surgeons EXCEPT:
Decline gifts from industry with a market value over $100 (unless they are medical textbooks or patient educational materials)
Disclose to the patient any financial arrangements with industry that relates to the patient's treatment
Accept no direct financial inducements from industry for utilizing a particular implant
Disclose any relationship with industry to colleagues who may be influenced by your work
Decline to participate in industry sponsored non-CME courses or
conferences
The AAOS has adopted the Standards of Professionalism (SOP). These SOP’s establish mandatory, minimum levels of acceptable conduct for fellows and members of the AAOS to engage in relationships with industry. There are 17 standards with relation to industry. Answer choice 5 is not a SOP as surgeons are allowed to participate in or consult in meetings that are conducive to the effective exchange of information. The SOP also stipulate that tuition, travel, and modest hospitality (including meals and receptions) are allowed to attend an industry-sponsored non-CME course.
A prospective randomized trial is conducted to test the efficacy of Vitamin C versus placebo in treating patients who develop chronic regional pain syndrome (CRPS) after distal radius fractures. At first follow-up, the rates of CRPS are 1% and 9% in the study and placebo group, respectively. Which statistical test is most appropriate to determine significance?
Single factor analysis of variance
Chi-square test
Student t-test
Mann-Whitney rank sum test
Wilcoxon rank sum test
In the study provided, we need to determine whether distributions of categorical variables differ from one another. The appropriate study is the chi- square test.
Data can be classified as numerical (continuous) or categorical (proportional). Responses to such questions as "What is your major?" or Do you own a car?" are categorical because they yield data such as "biology" or "no." In contrast, responses to such questions as "How tall are you?" or "What is your G.P.A.?" are numerical. When comparing two independent means from numeric data, a t-test is performed. However, if categorical data is being compared, the chi- square test will determine if the proportions are really different.
Kocher et al. review basic clinical epidemiology and biostatistics relevant to orthopaedic surgery. Amongst other things, they describe that data can be summarized in terms of measures of central tendency, such as mean, median, and mode, and in terms of measures of dispersion, such as range, standard deviation, and percentiles.
Illustration A shows an algorithm for determining which test to use for varying data. Incorrect Answers:
distributed.
A 35-year-old patient is involved in a motor vehicle accident and sustains multiple fractures including a closed comminuted proximal meta-diaphyseal tibia fracture. The surgeon is considering bridge plating the fracture using a minimally invasive approach. Which of the following is true regarding bridge plating?
A locked plate construct (locked screws) or hybrid construct (locked and non- locked screws) is necessary.
Periosteal stripping is performed through two incisions proximal and distal to the fracture.
Bridge plating is performed following direct reduction of the fracture.
AO Type A diaphyseal fractures are best treated with this technique.
Bridge plating with a long working length creates a flexible, axially stable construct.
In bridged plating, only the most proximal and distal screw holes are filled. This creates a flexible, axially stable construct.
Bridge plating is applicable to all long-bone fractures with complex fragmentation and where intramedullary nailing or conventional plate fixation is not suitable. The construct preserves the blood supply to the fracture fragments as the fracture site is undisturbed during the operative procedure. It provides RELATIVE stability, allowing for some motion at the fracture site, leading to callus formation and secondary bone healing. The construct is FLEXIBLE because of increased distance between the 2 screws closest to the fracture (long working length), allowing for stress distribution and permitting more motion at the fracture site. The construct is also AXIALLY STABLE because the plate acts as an extramedullary splint and resists axial compression.
Livani et al. advocate using an anterior or antero-lateral approach for minimally invasive plating of the humerus. They recommend that distal access is obtained first, allowing identification of the lateral antebrachial cutaneous nerve. For distal fractures, they recommend extending the plate down to the lateral column.
Apivatthakakul et al. defined minimally-invasive plate osteosynthesis (MIPO) danger zones from the lateral epicondyle. They found the musculocutaneous nerve averaged 18- 43% of the humeral length, the danger zone for the radial nerve averaged 36-59% of the humeral length, and the most dangerous screws that penetrated or touched the radial nerve lay 47-53% of the humeral length.
Illustration A shows a distal tibia fracture. Illustration B shows radiographs 5 months after bridge plating of this fracture. There is callus formation, characteristic of indirect bone healing.
periosteal blood supply is critical.
Which of the following components of bone is most responsible for compressive strength?
Type I collagen
Osteocalcin
Proteoglycans
Osteonectin
Osteopontin
Proteoglycans, in addition to calcium hydroxyapatite [Ca10(PO4)6(OH)2], are most responsible for providing compressive strength.
Bone is composed of both organic and inorganic components. Inorganic components include calcium hydroxyapatite and osteocalcium phosphate. Organic components include collagen, proteoglycans, matrix proteins, cytokines and growth factors. While Type I collagen is responsible for providing the tensile strength of bone, proteoglycans and calcium hydroxyapatite [Ca10(PO4)6(OH)2] are most responsible for providing compressive strength. Proteoglycans contain a core protein with various
numbers of covalently attached side chains of glycosaminoglycans. In addition to providing compressive strength, they are also responsible for binding growth factors and inhibiting mineralization.
Knothe et al. review the osteocyte. They discuss that osteocytes are the most abundant
cells in bone, are actively involved in maintaining the bony matrix, and may act as mechanosensors.
Illustration A shows a proteoglycan aggregate, which can form when individual molecules link onto a chain of hyaluronic acid.
Incorrect Answers:
A prospective, randomized controlled trial of 150 patients undergoing total hip arthroplasty is performed to test whether repair of the capsule during a posterior approach reduces post-operative dislocations in the first three months. The study found no difference in dislocation rate if the capsule was repaired versus not repaired (p =
.34). Subsequently, a multicenter follow-up study of 2000 patients showed that repairing the capsule led to a decreased dislocation rate
in the first three months (p = .03). Assuming the second study reflects reality, which of the following errors occurred in the first study?
Observer bias
Type-II error
Alpha error
Type-I error
Confounding error
In this situation, the null hypothesis was accepted when it should have been rejected.
This is a type-II error.
A study can have two types of errors. Type-I errors, or alpha errors, occur when the null hypothesis is rejected when it should have been accepted. The alpha level refers to the probability of a type-I error. By convention, the alpha level of significance is set at 0.05, which means that we accept the finding of a significant association if there is less than a one in twenty chance that the observed association was due to chance alone. Type-II errors, or beta errors, occur when the null hypothesis is accepted when it should be rejected. This
often occurs when studies are underpowered. In the example above, the null hypothesis is that repair of the capsule does not reduce dislocations within the first three months. Since the first study did not show a statistically significant difference, the null hypothesis was accepted. Since a more powered study showed that repair of the capsule does reduce dislocations, the null hypothesis should have been rejected in the initial study (if it was adequately powered).
Fosgate et al. review the importance of sample size calculations when performing research. They state that sample size ensures statistical significance if the subsequent data collection is perfectly consistent with the assumptions made for the sample size calculation (assuming power was set as
50% or greater).
Illustration A shows the difference between type-I and type-II errors. Video V is a lecture discussing statistical definition review of PPV, NPV, sensitivity and specificity.
Incorrect Answers:
that properly constructed studies attempt to avoid.
Which of the following is a potential cause of fretting corrosion?
The micromotion at the femoral head-neck junction in a modular total hip replacement
A stainless-steel cerclage wire is in contact with a titanium-alloy femoral stem
Friction between polyethylene liner and femoral head leading to osteolysis
The formation of pits within a stainless-steel plate and the subsequent release of metal ions
The formation of an adherent oxide coating on titanium implants
Micromotion at the femoral head-neck junction can lead to fretting corrosion, one of the most common causes of failure of a modular implant.
Modular components give surgeons excellent intraoperative flexibility, but are susceptible to various types of corrosion. While titanium and cobalt-chrome contain a protective surface oxide layer, continued micromotion at the modular junction may disrupt the protective layer leading to fretting corrosion, defined as micromotion at contact sites under load. This may eventually lead to a painful synovitis that necessitates a revision procedure.
Srinivasan et al. review modularity in total hip arthroplasty. Amongst other things, they discuss the modularity of the femoral head/neck junction, describing the morse taper interlocking system that provides both axial and rotational stability.
Illustration A shows an example of corrosion at the head/neck junction of a total hip arthroplasty.
Incorrect Answers:
Which of the following situations is most likely to decrease sentinel event errors?
Physician and nurse training is lengthened by 20%
Resident hours are decreased to 55 hours per week
An environment is created where all members of the healthcare team feel empowered to express their concerns and beliefs
Holding individuals responsible for errors in clinical judgement
Physicians and nurses are assigned to a smaller number of patients
Creating an environment where all members of the healthcare team feel empowered to express their beliefs increases communication, the key element in decreasing sentinel events.
Research has shown that 70% of sentinel event errors are caused by improper communication. Specific ways to improve communication include effective clinical handover between shifts and breaking down the "hierarchy" so that all members of the team can discuss their expectations and concerns. Barriers to effective communication include distractions, cultural differences, power distance relationships, time pressures, and lack of organization.
Leonard et al. describe specific clinical experiences in the application of surgical briefings, properties of high reliability perinatal care, the value of critical event training and simulation, and benefits of a standardised communication process in the care of patients transferred from hospitals to skilled nursing facilities. They recommend embedding standardized tools and behaviors to bridge differences in communications styles between clinicians.
Incorrect Answers:
Which of the following side effects is most strongly associated with the use of NSAIDs?
Hepatic dysfunction
Renal impairment
Prolonged QTc
Seizures
Hematuria
All NSAIDs have the potential to cause serious renal impairment.
NSAIDs work by inhibiting the cyclooxygenase pathway (COX), which is comprised of the COX-1 and COX-2 pathways. The COX-1 pathway is involved in prostaglandin E2– mediated gastric mucosal protection and thromboxane effects on coagulation, while the COX-2 pathway is mainly involved with the modulation of pain and fever without effect on platelet function. While selective COX-2 inhibitors have a decreased side effect profile, all NSAIDS
have the potential to cause renal impairment and their use should be limited in patients with underlying renal disease.
Horlocker et al. review multimodal pain management in the perioperative setting of a total joint arthroplasty. Specifically, they note that NSAIDs should be used cautiously in patients with underlying renal dysfunction who are to undergo a procedure with major blood loss.
Griffin et al. reviewed 1,799 patients hospitalized for acute renal failure. They found that NSAIDs increased the risk of renal failure by 58% and that NSAID use resulted in 25 excess hospital admissions per 10,000 years of use.
Illustration A shows the COX pathways and their inhibition by NSAIDs. Incorrect Answers:
It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?
Glucosamine
Cholecalciferol
Levothyroxine
Teriparatide
Bisphosphonates
Bisphosphonate therapy combined with invasive dental work increases the risk for development osteonecrosis of the jaw.
Bisphosphonates are a class of drugs that prevent bone mass loss by inhibiting osteoclast resorption. They are used in the treatment of vertebral compression fractures, non- vertebral fragility fractures, osteogenesis imperfecta, multiple myeloma, and avascular necrosis. Because bisphosphonates have been associated with osteonecrosis of the jaw, it is suggested that all invasive
dental work be completed prior to initiation of treatment.
Pazianas et al. (2011) review the safety profile of bisphosphonates. Specifically, they cite gastrointestinal discomfort, atypical femur fractures, osteonecrosis of the jaw, ocular inflammation, and musculoskeletal pain as common side effects. They state there is limited evidence surrounding
bisphosphonate's association with esophageal cancer and atrial fibrillation.
Pazianas et al. (2007) reviewed 11 publications that reported 26 cases of osteonecrosis of the jaw following initiation of bisphosphonate treatment. Age
>60 years, female sex, and previous invasive dental treatment were the most common characteristics of those who developed ONJ.
Illustration A shows the various bisphosphonates and their mechanisms of action. Illustration B shows an example of osteonecrosis of the jaw, a side effect that has been linked to bisphonphonate treatment.
Incorrect Answers:
Figures A and B show radiographs of a 24-year-old female with a soccer injury. A physical examination reveals an isolated, closed injury with no clinical features of neurovascular injury or compartment syndrome. She has been consented to be treated with intramedullary nail fixation. A pre-operative note by the anaesthesiology team makes reference to the patients fair skin and natural red-hair color. How will this information affect the post-operative management of this patient?
Longer duration of anticoagulation due to increased risk of DVT
Avoiding anticoagulation medications due to increased risk of bleeding
Require higher dosages of post-operative analgesia
Longer period of non-weight bearing on surgical limb
Avoiding opioids due to higher risk of unrecognized allergies
Female patients with natural red-hair may require higher dosages of post- operative analgesia compared to other hair types.
Melanocortin-1-receptor (MC1R) is one of the key proteins involved in hair color and skin tone. Mutations of the MC1R alleles can render this protein non- functional, which results in a phenotype of red-hair and fair skin. Mutations of the MC1R have shown to modulate the pain response and opioid efficacy in these patients. Women are more commonly affected and often require more anaesthetic and higher dosages of opioid to achieve comparable MAC level and pain-relief, respectively, as women with other hair types.
Liem et al. showed that a greater concentration of induction and maintenance agents (sevoflurane and desflurane, respectively) were required to sustain comparable MAC levels in red-haired patients as dark haired patients.
Fillingim et al. reviewed the affect of gender, sex and pain. They concluded there is a biopsychosocial element of pain that is perceived differently by men and women. In terms of postoperative and procedural pain, the outcome might be more severe in women than men.
Delaney et al. looked at the involvement of the melanocortin-1 receptor in acute pain in mice. They found that while the MC1R is better known as a gene involved in mammalian hair colour, it was shown to be involved in the pain pathway of inflammatory but not neuropathic origin. Mutations of MC1R showed increased tolerance to noxious pain stimulus in mice.
Figures A and B are AP and lateral radiographs of a left tibia. There is a low energy, distal third shaft fracture with no cortical apposition on the AP view.
Incorrect Answers:
Which of the following medications used for thromboprophylaxis following orthoapedic surgery is a direct inhibitor of factor Xa?
Dextran
Rivaroxaban (Xarelto)
Coumadin
Fondaparinux (Arixtra)
Aspirin
Rivaroxaban (Xarelto), an oral anticoagulant, is a direct inhibitor of factor Xa.
Rivaroxaban (Xarelto) is a member of a new class of oral, direct (antithrombin- independent) factor Xa inhibitors, which restrict thrombin generation both in vitro and in vivo. Inhibition of Factor Xa interrupts the intrinsic and extrinsic pathway of the blood coagulation cascade, inhibiting both thrombin formation and development of thrombi.
Eriksson et al. compare rivaroxaban to enoxaparin for the prevention of symptomatic venous embolism following total hip arthroplasty. Major venous thromboembolism occurred in 4 of 1686 patients (0.2%) in the rivaroxaban group and in 33 of 1678 patients (2.0%) in the enoxaparin group. Additionally, major bleeding events were similar between the two groups.
Illustration A shows the mechanisms of action of various agents used for thromboprophylaxis.
Incorrect Answers:
as Protein C and Protein S.
The origin of bovine derived grafts is particularly important to which of the following religious groups?
Christianity
Islam
Hinduism
Buddhism
Judaism
The origin of bovine-derived surgical implants should be discussed in further detail with patients ascribing to Hinduism.
Patients come from a variety of religious backgrounds. Depending on a patient’s religion, the origin of surgical implants may have implications for their use. In Hinduism, bovine animals are considered sacred. Use of cow by- products is considered purifying in nature. Subsequently, the origin of bovine derived implants should be discussed with patients ascribing to Hinduism.
Easterbrook et al. evaluated the utility of porcine and bovine surgical implants amongst those of Jewish, Muslim and Hindu faiths. Hindu religious leaders, who were surveyed, did not approve of the use of bovine surgical implants.
Enoch et al. evaluated the acceptability of biological products amongst various religious groups. The Hindu religious leaders were found to not have an objection to the use of biological implants derived from cows.
Illustration A shows a clinical photo of a fetal bovine derived dermal substitute. Incorrect Answers:
Immunological testing of anti-cyclic citrullinated peptide antibodies (anti- CCP) is most commonly used for the diagnosis and prognosis of which immunological condition?
Ankylosis spondylitis
Rheumatoid arthritis
Psoriatic arthritis
Systemic lupus erythematosus
Reiter's syndrome
Anti-cyclic citrullinated peptide antibodies (anti-CCP) are commonly used as a marker for the diagnosis and prognosis of rheumatoid arthritis (RA).
Immunological studies are commonly performed to investigate cases of suspected rheumatoid arthritis. Rheumatoid factor has historically been used as a primary marker for RA. However, in more recent years, the use of anti- CCP antibodies has shown to be as sensitive as, and more specific than, rheumatoid factor (RF) in early and fully established disease. In general, anti-
CCP assays equate to a sensitivity of 50-75% and a specificity of 90-95%. High levels of anti-CCP have been shown to be indicative of a more erosive disease process and may be detected before the onset of arthritis.
Gardner and Kadel reviewed the laboratory studies most commonly used in rhuematologic diseases. Standard ordering for clinically suspected RA include Rf, anti- CCP, ESR/CRP as well as other markers of autoimmune diseases such as antinuclear antibodies, anticardiolipin antibodies and lupus anticoagulant, HLA-B27, and uric acid levels.
Illustration A shows the sensitivity and specificity of anti-CCP vs. RF in a variety of autoimmune diseases.
Incorrect Answers:
Vitamin C has been shown to decrease the likelihood of which of the following complications following surgery on the foot and ankle in non-diabetic patients?
Nonunion
Complex Regional Pain Syndrome, type II
Malunion
Complex Regional Pain Syndrome, type I
Wound infection
Vitamin C has been shown to decrease the likelihood of developing complex regional pain syndrome (CRPS), type 1, when given post-operatively to patients undergoing foot and ankle and wrist surgery.
CRPS is a frequent post-operative complication, with rates varying from 10-
37%. Type I CRPS does not have an identifiable nerve lesion, while type II has an identifiable nerve lesion. Multiple studies have shown that vitamin C decreases rates of CRPS following distal radius fractures, and more recently, the same has been shown following foot and ankle surgery. While the exact mechanism of CRPS is unknown, vitamin C has been shown to reduce lipid peroxidation, scavenge hydroxyl radicals, protect the capillary endothelium, and inhibit vascular permeability. All of these characteristics of vitamin C may play a role in modulating the pain pathway.
Zollinger et al. perform a double-blind, prospective, multicenter trial where
416 patients with 427 wrist fractures were randomly allocated to treatment with placebo or treatment with 200, 500, or 1500 mg of vitamin C daily for fifty days. The prevalence of complex regional pain syndrome was 2.4% in the vitamin C group and 10.1% in the placebo group.
Besse et al. compare two groups of patients undergoing surgery on the foot and ankle to determine the effect of vitamin C on the development of CRPS, type I. CRPS type I occurred in 18 cases (9.6%) in the group not given vitamin C, and 4 cases (1.7%) in the group given vitamin C.
Illustration A shows an example of a limb affected by CRPS. Note the increased swelling, a common physical exam finding in patients afflicted with the disease.
Incorrect Answers:
A 25-year-old Spanish speaking male presents to the emergency department 6 hours after sustaining the injury seen in Figure A. He is grossly intoxicated and screaming in pain. Physical examination reveals a closed injury with overlying muscular compartments that are extremely firm to palpation. After sedating the patient, measurements of the intracompartmental pressures were all found to be
>75mmHg. His wife is Spanish speaking and expected to arrive to the hospital in 2-3 hours with a relative to help with translation. No medical translator is
available. You attempt to outline the risk and benefits of surgery to the patient, but the he repeatedly interrupts you and yells out ,"No surgery!". An English-Spanish speaking friend is with the patient and says that he has known the patient for over 2 years and will help with any decision making. What would be the next most appropriate step in the management of this patient?
Delay surgery to monitor the patient for impending compartment syndrome
Proceed with surgery with urgent fasciotomy after documenting the necessity of treatment without consent
Delay the surgery until the wife arrives and able to give informed consent with the aid of a translator
Proceed with surgery for urgent fasciotomy after obtaining informed consent from the patients friend
Respect the patients autonomy and reassess the patient in the morning when he demonstrates capacity to accurately comprehend the proposed treatment
This patient is presenting with compartment syndrome of the right tibia. In a situation of required surgery for limb threatening injury without available legal consent the surgeon should confirm and document the necessity of care with a fellow colleague.
Physicians are responsible for whether a patient is able to reasonably understand their medical condition and the nature of any proposed medical procedure, including the risks, benefits, and available alternatives. If the patient lacks this capacity, disclosure imposed by the doctrine of informed
consent are excused because irreparable harm that may result from the physician’s hesitation to provide treatment. Detailed documentation is also important. In addition, the attending physician should contact the Risk Management Dept at the hospital for support prior to surgical intervention or have a medical translator involved to ensure information is being translated properly.
Katz et al. reviewed the medical decision making process of Hispanic people. They showed that Hispanic people are more likely to permit their physician to take the predominant role in making health decisions compared to Non- Hispanic people.
Figure A shows a comminuted tibia and fibula fracture. Incorrect Answers
A Spanish speaking child sustained the injury seen in Figure A after a fall at school. He was casted in the emergency department without the assistance of an interpreter and advised to return to see an orthopaedic surgeon in 1 week. However, the family returns to the emergency department with the child 3 months later, still in the cast. What is the most likely reason the child did not attend the recommended orthopaedic follow-up visit.?
The child is a victim of neglect
The child had no symptoms of pain
He was allowed to return to school wearing the cast
Concerns of cost
Follow-up instructions were not effectively communicated
The most likely reason the child did not attend the recommended orthopaedic follow-up visit was a language barrier preventing effective communication of the intended follow-up instructions.
Communication skills and cultural competence is a key element in good orthopaedic care. Poor communication can often lead to devastating outcomes. In this example, poor communication resulted in this patient being lost to
follow-up. Language barriers must be accommodated and alternative methods of communication must be utilized.
Levinson et al. examined how patients present their medical issues in clinical encounters and how physicians respond to these clues in routine primary care and surgical settings. They showed that good communication relies mostly on the physicians ability to identify patient clues within the clinical encounter.
Poor communication between the physician tended to delay clinical visits, poor follow-up and unsatisfactory outcomes.
Figure A is an AP radiograph of the elbow in a skeletally immature patient. Figure B is a lateral radiograph of the elbow with a posterior fat pad sign, suggestive of an occult fracture.
Incorrect Answers:
A 25-year-old female presents to the emergency room within increasing left shoulder pain after walking into a door 5 months ago. She previously sustained a femoral fracture 2 years ago after tripping on a rug. Relevant skeletal survey radiographs and tissue biopsy results are shown in Figures A through D. Laboratory investigations show normal glomerular filtration rate and creatinine clearance. Dual energy x-ray absorptiometry (DEXA) scan shows T-score of -1.4 and
-1.2 at the hip and lumbar spine, respectively. Which of the following laboratory values in Figure E most likely reflects this patient's condition?
A
B
C
D
E
This patient has primary hyperparathyroidism. Laboratory investigations are likely to show elevated serum intact parathyroid hormone (PTH), alkaline phosphatase (ALP) and ionized serum calcium, and low serum phosphate.
Primary hyperparathyroidism is most commonly caused by a single adenoma (80-90%). Besides the signs and symptoms of hypercalcemia, patients present
with calcification of menisci and articular cartilage, erosions in hand bones, "salt and pepper skull", and brown tumors (osteoclastomas), which appear as lytic regions expanding the cortex and causing pathological fractures, so named because of hemosiderin deposition.
Singhal et al. reviewed primary hyperparathyroidism. They advocate routine serum calcium levels for patients with pathologic fractures. If this is elevated, total and ionized calcium and intact PTH levels should be obtained. They feel that surgery for orthopaedic stabilization and parathyroidectomy should be performed simultaneously for better outcome.
Mankin et al. reviewed metabolic bone disease. They suggest that patients with mild disease with normal calcium levels do not require treatment. For patients with high calcium levels, treatment should include maintenance of fluid balance, localization and removal of the adenoma, bony stabilization, and medications (calcitonin, estrogen, bisphosphonates, and calcimimetics such as cinacalcet).
Figure A is an AP radiograph showing a lytic expansile lesion with pathological fracture in metadiaphyseal region of left humerus with similar lesion in the
fifth posterior rib. Figure B is an AP radiograph showing a lytic expansile lesion in the third metacarpal of the right hand and the fifth metacarpal of the left hand. Figure C is a low power micrograph of a brown tumor demonstrating a central zone of bone resorption, and filling with fibroblastic tissue, with a peripheral rim of osteoid production. Figure D is a high power micrograph of a brown tumor. In areas of bone resorption, there are numerous osteoclast-like giant cells amidst a fibrous stroma. This is unlike a true giant cell tumor, which lacks a fibrogenic stroma.
Incorrect Answers:
and impaired 1,25-dihydroxyvitamin D production by the diseased kidneys. This patient has normal renal function. Answer 3: Elevated PTH, ALP, serum calcium and phosphate occur in tertiary hyperparathyroidism. This again occurs in chronic renal disease after prolonged chronic secondary hyperparathyroidism or after renal transplantation, where the parathyroid glands become autonomous and PTH levels do not normalize. This patient has normal renal function.
elevated.
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Question 81

Figures below show the radiographs, and the MRIs obtained from a 32-year-old man with worsening left knee pain. A 3-foot hip-to-ankle radiograph shows a 13-degree varus knee deformity. The patient sustained a major left knee injury 5 years ago and a confirmed complete anterior cruciate ligament (ACL) tear. He managed this injury nonsurgically with a functional brace but experienced worsening pain. He was seen by an orthopaedic surgeon 18 months ago, and a medial meniscus tear was diagnosed; the tear was treated with an arthroscopic partial medial meniscectomy. Since then, his knee has been giving way more often, and he no longer feels safe working on a pitched roof. The patient received 6 months of formal physical therapy and was fitted for a new functional ACL brace, but he still has pain and instability. He believes he has exhausted his nonsurgical options and would like to undergo surgery. What is the most appropriate treatment at this time?

Explanation

DISCUSSION:
Proximal tibial osteotomy is the most appropriate intervention to correct varus malalignment and to reduce stress on the ACL. In some cases, proximal tibial osteotomy alone may address both pain and instability, but if instability persists, particularly in the setting in which instability can be dangerous, subsequent ACL reconstruction can further stabilize the knee with less stress on the graft after the correction of malalignment. Varus alignment places increased stress on the native or reconstructed ACL. ACL reconstruction should be performed only at the same time as or following proximal tibial osteotomy to correct alignment in the setting of varus malalignment. It is not appropriate to perform ACL reconstruction prior to proximal tibial osteotomy in this setting. Distal femoral osteotomy is not indicated to correct varus malalignment. Varus alignment places increased stress on the native or reconstructed ACL, and ACL reconstruction alone is not indicated for this patient.

Question 82

A 43-year-old man sustained a closed, intra-articular pilon fracture. It has now been 1 year since he underwent open reduction and internal fixation. Which of the following statements most accurately describes his perceived outcome? Review Topic

Explanation

Marsh and associates retrospectively reviewed 56 tibial plafond fractures and found that the patients perceived improvement in their function and pain for an average of

Question 83

Two years after undergoing a total shoulder arthroplasty, a patient reports increasing pain, stiffness, and swelling, and has an increased white blood cell count. Radiographs show lucencies around the glenoid and humeral components. You suspect infection. Which of the following is the most likely responsible organism? Review Topic

Explanation

The most likely organism to cause late infection in shoulder arthroplasty is Propionibacterium acnes. This is a slow growing organism that is present in over 50% of chronic infections. Staphylococcus epidermidis is the second most likely organism in this setting, present in 15% of cases. The other three organisms are unlikely to present with this clinical picture.

Question 84

A 42-year-old patient has had painful inferior subluxation of the glenohumeral joint following a recent cerebrovascular accident (CVA). Figure 34 shows the AP radiograph of the shoulder. Management should consist of

Explanation

DISCUSSION: Following a CVA and with the resumption of upright posture, downward subluxation of the glenohumeral joint may occur. Although usually painless, some patients may report pain secondary to stretching of the brachial plexus. This is the result of flaccid paralysis of the deltoid muscle, and it will persist until some motor tone or spasticity returns to the shoulder girdle musculature. Early sling support and range-of-motion exercises to prevent contracture will provide the best relief. Surgical procedures are not indicated.
REFERENCES: Braun RM, Botte MJ: Treatment of shoulder deformity in acquired spasticity. Clin Orthop 1999;368:54-65.
McCollough NC III: Orthopaedic evaluation and treatment of the stroke patient. Instr Course Lect 1975;24:45-55.

Question 85

The patient returns 1 year later to report curling of her toes and numbness on the plantar surface of her foot. What is the most likely cause of this condition?

Explanation

DISCUSSION
Radiographs reveal a Lisfranc fracture dislocation with fractures of the first and second metatarsals. Tenting of skin that is over a bony prominence is an orthopaedic emergency. The fracture dislocation should be reduced without delay. There is no evidence of compartment syndrome of the foot, but this may develop and monitoring is necessary. Toe deformity may develop on a delayed basis because of the subclinical presentation. Nerve irritation is not uncommon with dorsal midfoot surgical incisions. A positive Tinel test result over the midfoot in the distribution of the superficial common peroneal nerve is consistent with a stretch injury to this nerve. CRPS is usually associated with multiple nerve distributions and autonomic nerve findings such as cold hypersensitivity and hyperhidrosis.
RECOMMENDED READINGS
Benirschke SK, Meinberg EG, Anderson SA, Jones CB, Cole PA. Fractures and dislocations of the midfoot: Lisfranc and Chopart injuries. Instr Course Lect. 2013;62:79-91. PubMed PMID: 23395016. View Abstract at PubMed
Schepers T, Oprel PP, Van Lieshout EM. Influence of approach and implant on reduction accuracy and stability in lisfranc fracture-dislocation at the tarsometatarsal joint. Foot Ankle Int. 2013 May;34(5):705-10. doi: 10.1177/1071100712468581. Epub 2013 Jan 14. PubMed
PMID: 23637239. View Abstract at PubMed

Question 86

A patient sustains a closed dorsal dislocation of the proximal interphalangeal joint of the middle finger without an associated fracture. Closed treatment results in a cocentric stable reduction. The finger is not immobilized. Which of the following conditions may appear 1 year later?

Explanation

Examination of a 3-year-old boy who slammed his finger in a door 3 months ago reveals 0 to 40 degrees of proximal interphalangeal joint motion. Radiographs are shown in Figures 47a and 47b. Management should consist of
Volar osteotomy
Observation only
Flexor tenolysis
Volar plate arthoplasty
A hinged distraction external fixator
Subcondylar fractures of the proximal and middle phalynx occur at the neck of the phalynx, usually as a result of a crush injury, and almost exclusively in the pediatric age group. The distal fragment rotates dorsally and the degree of displacement may be misjudged if a true lateral is not obtained. If malunion occurs there is block to flexion. Subcondylar fossa reconstruction by removal of bone through a palmar approach removes this boney block.

Question 87

What is the most frequent late complication of cementless fixation in total knee arthroplasty?

Explanation

DISCUSSION: The incidence of osteolysis, particularly around fixation screws in the tibia, can be as high as 30%. Stable femoral component fixation is generally maintained. Infection, subluxation of the patella, and stiffness can occur with either cemented or cementless fixation.
REFERENCES: Peters PC, Engh GA, Dwyer KA, Vinh TN: Osteolysis after total knee arthroplasty without cement. J Bone Joint Surg Am 1992;74:864-876.
Parks NL, Engh GA, Topoleski LDT, Emperado J: Modular tibial insert micromotion: A concern with contemporary knee implants. Clin Orthop 1998;356:10-15.

Question 88

Based on the Young and Burgess classification of pelvic ring injuries, an anterior-posterior compression type II injury does not result in disruption of which of the following?

Explanation

DISCUSSION: An APC type 1 involves slight widening of pubic symphysis and/or anterior sacroiliac (SI) joint. An APC II is a continuation of this force, and additionally involves a disrupted anterior SI joint, as
well as sacrotuberous and sacrospinous ligaments. An APC III also involves disrupted posterior SI ligaments, causing complete SI joint disruption with potential translational and rotational displacement.
The reference by Young et al is a classic article that describes the Young and Burgess classification of pelvic ring injuries. They retrospectively analyzed pelvic ring radiographs and discussed four patterns of injury: anteroposterior compression, lateral compression, vertical shear, and a complex/combined pattern.
The reference by Burgess et al is a validation of the aforementioned classification and study, as they reviewed 210 consecutive patients who sustained a pelvic ring injury. They validated the classification scheme and found that overall blood replacement averaged: lateral compression, 3.6 units; anteroposterior compression, 14.8 units; vertical shear, 9.2 units; combined mechanical, 8.5 units. Overall mortality was: lateral compression, 7.0%; anteroposterior, 20.0%, vertical shear, 0%; combined mechanical, 18.0%.
Incorrect answers:
1,2,4,5: An APC - 2 pelvic ring injury involves injury to all of these structures.

Question 89

A 35-year-old patient is involved in a motor vehicle accident and sustains multiple fractures including a closed comminuted proximal meta-diaphyseal tibia fracture. The surgeon is considering bridge plating the fracture using a minimally invasive approach. Which of the following is true regarding bridge plating? Review Topic

Explanation

In bridged plating, only the most proximal and distal screw holes are filled. This creates a flexible, axially stable construct.
Bridge plating is applicable to all long-bone fractures with complex fragmentation and where intramedullary nailing or conventional plate fixation is not suitable. The construct preserves the blood supply to the fracture fragments as the fracture site is undisturbed during the operative procedure. It provides RELATIVE stability, allowing for some motion at the fracture site, leading to callus formation and secondary bone healing. The construct is FLEXIBLE because of increased distance between the 2 screws closest to the fracture (long working length), allowing for stress distribution and permitting more motion at the fracture site. The construct is also
AXIALLY STABLE because the plate acts as an extramedullary splint and resists axial compression.
Livani et al. advocate using an anterior or antero-lateral approach for minimally invasive plating of the humerus. They recommend that distal access is obtained first, allowing identification of the lateral antebrachial cutaneous nerve. For distal fractures, they recommend extending the plate down to the lateral column.
Apivatthakakul et al. defined minimally-invasive plate osteosynthesis (MIPO) danger zones from the lateral epicondyle. They found the musculocutaneous nerve averaged 18-43% of the humeral length, the danger zone for the radial nerve averaged 36-59% of the humeral length, and the most dangerous screws that penetrated or touched the radial nerve lay 47-53% of the humeral length.
Illustration A shows a distal tibia fracture. Illustration B shows radiographs 5 months after bridge plating of this fracture. There is callus formation, characteristic of indirect bone healing.

Question 90

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

Explanation

DISCUSSION: The radiographs show displacement of the prosthesis, and there has been large amounts of bone resected to insert the implant. Arthrodesis is indicated with interposition bone graft to stabilize the joint and restore length to the first ray.
REFERENCE: Myerson MS: Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, pp 265-266.

Question 91

A 53-year-old man has a 4- x 5-cm high-grade soft-tissue sarcoma in the midthigh. As part of the staging evaluation, regional nodes should be assessed by

Explanation

DISCUSSION: In general, soft-tissue metastases to regional nodes are a relatively rare occurrence (less than 5% overall). The incidence of lymphatic metastasis is highest for synovial sarcoma, rhabdomyosarcoma, clear cell sarcoma, and epithelioid sarcoma. Regional nodes should be assessed clinically. CT is not used to routinely assess regional nodes. Evaluation of a sentinal node is not indicated because of the low incidence of regional nodal involvement. Fine needle aspiration may be indicated to assess clinically suspicious nodes. Prophylactic inguinal node dissection is contraindicated because it may lead to unnecessary complications such as lymphedema.
REFERENCE: Sim FH, Frassica FJ, Frassica DA: Soft-tissue tumors: Diagnosis, evaluation and management. J Am Acad Orthop Surg 1994;2:202-211.

Question 92

-This boy’s parents are eager to get him back on the field as soon as possible. What is the most appropriate treatment option?

Explanation

DISCUSSION FOR QUESTIONS 60 AND 61
Although a recent increase in the number of pitches may have contributed to this patient’s development of little leaguer’s shoulder, the most significant overall factor is age. Little leaguer’s shoulder is caused by rotational stress placed on the proximal humeral epiphysis during overhead throwing. The growth plate is weakest to torsion stress, and is most susceptible to injury during periods of rapid growth commonly seen during puberty. Most chronic shoulder injuries occur in throwing athletes between 13 and 16 years of age. Genetic factors and gender have not been studied in association with little leaguer’s shoulder. An initial 3-month period of rest and activity modification will typically result in resolution of symptoms.Nonsteroidal anti-inflammatory drugs may be used as needed. After the rest period, a gradual return to baseline pitching is implemented until the patient is back to baseline. This protocol has a long-term success rate exceeding 90%.

Question 93

What structure (arrow) is shown in Figure 24?

Explanation

DISCUSSION: The structure illustrated is the sympathetic chain viewed from an anterolateral view of the lower lumbar spine. It descends along the anterolateral aspect of the spine into the pelvis closely adherent to the vertebral column. The spinal nerves, including L5, can be seen exiting from the foramen. The ureters descend from the kidneys and cross anterior to the iliac vessels to the bladder.
REFERENCES: Onibokun A, Khoo LT, Holly L: Anterior retroperitoneal approach to the lumbar spine, in Kim DH, Henn JS, Vaccaro AR, et al (eds): Surgical Anatomy and Techniques to the Spine. Philadelphia, PA, Saunders Elsevier, 2006, pp 101-105.
Netter GH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy Corporation, 1989.

Question 94

A 48-year-old male is involved in a motorycycle accident and arrives in the trauma bay in hypovolemic shock. He receives 6 units of packed red blood cells during his resuscitation. Which of the following viral microbes is he most at risk of exposure from the transfusions?

Explanation

DISCUSSION: According to the article by Wang et al the risk of viral transmission following a screened blood donation is: 1 in 1.9 million donations for human immunodeficiency virus (HIV), 1 in 1.8 million donations for hepatitis C virus (HCV), and 1 in 205,000 donations for hepatitis B virus (HBV). West Nile and Human T-cell leukemia viruses are even more rare in the general population, and both are screened in blood banks. Hepatitis A virus is not a blood borne viral disease. It is contracted by the fecal-oral route. Staph Aures is a bacteria, not a virus.

Question 95

A 42-year-old man sustained a burst fracture at L2 in a motor vehicle accident. Examination reveals that he is neurologically intact. Figure 18 shows a cross-sectional CT scan through the fracture. If the fracture is managed nonsurgically for the next 2 years, the retained fragments can be expected to

Explanation

DISCUSSION: Numerous articles have reported that both surgical and nonsurgical management of burst fractures are associated with resolution of impingement at long-term follow-up. If the patient is neurologically intact and appropriately treated at the time of injury, neurologic deterioration is not expected nor is there a risk of injury to the dural sac. The retained fragments can be expected to gradually resorb and widen the spinal canal.
REFERENCES: Mumford J, Weinstein JN, Spratt KF, et al: Thoracolumbar burst fractures: The clinical efficacy and outcome of nonoperative management. Spine 1993;18:955-970.
Wood KB, Butterman G, Mehbod A, et al: Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurologic deficit: A prospective, randomized study. J Bone Joint Surg Am 2003;85:773-781.

Question 96

Which wear mechanism is most likely responsible for the wear damage on the modular tibial insert retrieval shown in Figure 82?

Explanation

DISCUSSION
The figure shows the top side of a retrieved tibial liner. Pitting and delamination, which are associated with fatigue wear, are noted. Creep is deformation without wear. Adhesive and abrasive wear is associated with removal of material on the back side of modular tibial components.
CLINICAL SITUATION FOR QUESTIONS 83 THROUGH 87
A bilateral cemented total knee arthroplasty (TKA) was performed on an otherwise healthy 63-year-old woman. The surgery and immediate postsurgical course were uneventful. Two days after surgery, while in physical therapy at the hospital, the patient’s oxygen saturation is noted at 92%.

Question 97

A 20-year-old college soccer player comes for an evaluation 6 months after an injury during which he landed awkwardly from a jump. Although physical therapy, ice, and activity modification have helped him return to baseline motion, strength, and swelling, he continues to have lateral knee pain. He also notes a popping sensation on the lateral side of his knee with activity. A Lachman test, anterior and posterior drawer tests, a pivot shift test, and McMurray test findings are all negative. MR images reveal a 12-mm x 15-mm osteochondral defect in the lateral femoral condyle with full-thickness cartilage loss and approximately 4 mm of subchondral bone loss.

Explanation

DISCUSSION
Patellofemoral pain in a young athlete without patellar instability or a chondral or osteochondral defect often can be managed with nonsurgical treatment such as physical therapy and a home exercise program. Microfracture surgery is associated with good short-term results for younger athletes. Patients with no history of prior surgery, primary chondral rather than osteochondral lesions, and lesions smaller than 2 cm have experienced the best results. Microfracture surgery performed for chondral lesions of the central aspect of the medial femoral condyle is associated with worse results. Decreased activity levels over time of patients who undergo microfracture surgery are a concern. OAT provides good outcomes and return-to-sports rates for athletic people who are younger and have lesions smaller than 2 cm. Patients with lesions on the lateral femoral condyle have better success rates. Both microfracture surgery and OAT provide better results for chondral defects than osteochondral defects. OAT is associated with better results than microfracture for medium-sized lesions between 2 cm and 4 cm, while autologous chondrocyte implantation yields better improvement for patients with defects larger than 4 cm. All of the surgical techniques listed for articular cartilage repair are associated with better outcomes for patients younger than age 30.

Question 98

ACL rehabilitation often includes exercises with the distal end of the extremity fixed in place with axial loading and co-contracture of muscle groups to help stabilize the joint. This type of exercise is more commonly referred to as: Review Topic

Explanation

A "closed chain exercise" is one in which the distal end of the extremity is fixed, allowing axial loading of the extremity with co-contracture of muscles decreasing stress across that joint.
Closed chain exercises are preferred for any rehabilitation protocol that wants to minimize stress across a potentially unstable joint. After ACL reconstruction it is important to begin motion and strengthening but not stress the reconstructed ligament which may lead to loss of stability or failure.
An example of a closed chain exercise of the quadriceps is a squat or leg press in which the foot is fixed against the floor/plate and both the quadriceps and hamstrings can contract together keeping the knee joint stable and preventing excess stress across the reconstructed ACL. An example of an open chain exercise of the quadriceps is a seated leg extension in which the foot is not fixed and the quadriceps contract in isolation. This creates a strong anterior pull on the tibia which can lead to excess stress on the ACL graft.
Beynnon et al. present a review on the behavior of ACL grafts during rehabilitation. They found that exercises that produce the least amount of stress across an ACL graft are either dominated by hamstring muscle contraction, involve quadriceps muscle activity with the knee flexed at 60° or greater, or involve active knee motion between
35°
and
90°
of
flexion.
Illustration A is an example of a squat, which is a closed chain exercise. Notice the feet are fixed in place against the floor. Illustration B is an example of a seated leg extension, which is an open chain exercise. Notice the feet are not fixed in place and no axial loading or co-contracture can occur.
Incorrect

Question 99

The spinal cord terminates as the conus medullaris at what vertebral level in adults? Review Topic 1 T12

Explanation

The spinal cord anatomy changes at the thoracolumbar junction. The spinal cord terminates as the conus medullaris at the lower portion of L1 in women and the pedicle of L1 in men.

Question 100

A 2-year-old girl has the fracture shown in Figures 5a and 5b. This fracture is most commonly associated with which of the following entities? Review Topic

Explanation

The radiographs reveal constriction of the tibial diaphysis in the region of the fracture, which is characteristic of the dysplastic type of pseudarthrosis of the tibia. Neurofibromatosis occurs in approximately 50% of children who have anterolateral bowing with or without pseudarthrosis of the tibia. The appearance of this fracture differentiates it from those resulting from child abuse. Type II osteogenesis imperfecta is usually lethal in the perinatal period. Radiographs in children with osteopetrosis show overly dense bones. Achondroplasia is not associated with fractures of the tibia.

Full Question & Answer Text (for Search Engines)

Question 1:

Options:

Lateralize the acetabular component, use a low offset femoral component, and make a shorter neck cut
Medialize the acetabular component, use a low offset femoral component, and make a longer neck cut
Lateralize the acetabular component, use a high offset femoral component, and make a shorter neck cut
Medialize the acetabular component, use a high offset femoral component, and make a longer neck cut

Correct Answer: Medialize the acetabular component, use a low offset femoral component, and make a longer neck cut

Explanation:

Question 2:

..First-line treatment recommendations include

Options:

synovectomy.
arthrocentesis, compressive wrap, and rest.
en bloc resection.
intra-articular radioactive nucleotide injection. DISCUSSION… The MRI scans reveal classic findings of PVNS with low signal on proton density and T2 sequences and evidence of “blooming” on gradient echo sequences. A discrete mass suggestive of a sarcoma (which would typically appear dark on T1 and bright on T2, but heterogenous and enhancing) is not seen, and synovial sarcomas rarely arise in an intra-articular location. Cartilaginous nodules of synovial chondromatosis are not seen, and the abnormal synovial process indicates that this is more than just a posttraumatic hemarthrosis. Treatment is synovectomy; radiotherapy is reserved for select recurrent cases. Arthrocentesis would be used for a simple hemarthrosis, and resection used for a sarcoma.

Correct Answer: en bloc resection.

Explanation:

Question 3:

An 18-year-old man sustains a twisting injury to the left knee while playing football. An MRI scan is shown in Figure 48. What is the most likely diagnosis? Review Topic

Options:

Anterior cruciate ligament rupture
Posterior cruciate ligament rupture
Medial meniscus tear
Lateral meniscus tear
Osteochondral lesion

Correct Answer: Lateral meniscus tear

Explanation:

Question 4:

Options:

Adductor tenotomy
Physical therapy
Observation
Abduction orthosis
Neurologic consultation

Correct Answer: Observation

Explanation:

Question 5:

Options:

increased laxity.
no differences in long-term results.
increased risk for graft failure.
lower Knee Injury and Osteoarthritis Outcome Scores (KOOS).

Correct Answer: no differences in long-term results.

Explanation:

DISCUSSION FOR QUESTIONS 44 AND 45
The Lachman test is the most sensitive examination for acute ACL injuries. ACL injury rates are higher in women than in men. This likely is attributable to anatomic differences (smaller notches, smaller ligaments, and different landing biomechanics). Lateral meniscal tears are more common than medial tears. The anterior drawer test is accentuated with 30 degrees of external rotation of the tibia. The MRI scan shows bone bruises consistent with an ACL tear. It is also always necessary to examine other structures of the knee in patients with ACL tears. All ligaments of the affected knee should be assessed.Lateral meniscal tears are frequently associated with ACL tears. Medial meniscal tears and posterolateral corner deficiency are also possible. Randomized clinical trials comparing an early accelerated vs nonaccelerated rehabilitation have demonstrated no significant differences in long-term results. These studies did not address timing of return to play with an early accelerated rehabilitation program. At 2 and 3 years postsurgically, there are no differences in laxity, number of graft failures, or KOOS scores.

Question 6:

Options:

Flexor carpi ulnaris to extensor carpi radialis brevis transfer
Fractional lengthening of the wrist and finger flexor tendons
Wrist arthrodesis with proximal row carpectomy
Botulinum toxin injection

Correct Answer: Wrist arthrodesis with proximal row carpectomy

Explanation:

EXPLANATION:
The patient has a static deformity of the wrist with a fixed flexion deformity of more than 45°. Soft-tissue procedures such as those referenced in options A and B would not be sufficient to address the degree of contracture. Additionally, Botulinum toxin injections would not provide relief for capsular contractures. Wrist arthrodesis combined with a proximal row carpectomy has been shown to provide a functional and
cosmetic alternative for patients with severe wrist flexion contractures.

Question 7:

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 8:

The patient has weakness with elbow flexion and has numbness down the anterior lateral aspect of the forearm.

Options:

Excessive medial placement of coracoid autograft
Excessive lateral placement of coracoid autograft
Excessive inferior dissection during the procedure
Excessive retraction and dissection of the medial portion of the conjoint tendon

Correct Answer: Excessive retraction and dissection of the medial portion of the conjoint tendon

Explanation:

Question 9:

Options:

Arthroscopy
MRI scan
Stress radiographs
Tomogram
Arthrogram

Correct Answer: Stress radiographs

Explanation:

Question 10:

A decrease in alkaline phosphatase would most likely be manifest in which metabolic disorder?

Options:

Familial hypocalciuric hypercalcemia
Hypophosphatasia
X-linked hypophosphatemia
Secondary hyperparathyroidism
Tertiary hyperparathyroidism

Correct Answer: Familial hypocalciuric hypercalcemia

Explanation:

Question 11:

Options:

Ewing’s sarcoma
Lymphoma of bone
Metastatic neuroblastoma
Langerhans cell histiocytosis
Osteomyelitis

Correct Answer: Langerhans cell histiocytosis

Explanation:

Question 12:

Options:

Humeral head arthroplasty
Total shoulder arthroplasty
Reverse shoulder arthroplasty
Arthroscopic debridement/capsular release
Corticosteroid injection and physical therapy

Correct Answer: Total shoulder arthroplasty

Explanation:

The patient has classic "arthritis of dislocation." Procedures done years ago were designed to enhance shoulder stability by limiting external rotation. However, it is now understood that limiting external rotation results in significant alteration of joint mechanics and kinematics, thus leading to the development of osteoarthritis. The average age of patients who develop `arthritis of dislocation` is 45 years old. Despite the young age of these patients, total shoulder arthroplasty offers the most predictable improvement in pain and function. However, the patient must be made aware of the need to protect the arm from excessive loads to protect the glenoid implant. Because there is complete loss of articular cartilage and incongruent joint surfaces, there is no role for arthroscopic debridement and capsular release. Injections offer little, if any, chance of improvement with the prior history of nonresponse. Physical therapy predictably makes patients worse because loading the arthritic joint generates more pain. Reverse shoulder arthroplasty is reserved for elderly patients with severe rotator cuff deficiency. A humeral head arthroplasty, while potentially more ideal than a total shoulder arthroplasty because of glenoid concerns, would likely not offer pain relief in the face of the significant glenoid involvement and incongruity.

Question 13:

Which of the following is the strongest contraindication to unicompartmental knee arthroplasty (UKA)?

Options:

Patient age of younger than 60 years
Patient age of older than 80 years
Anterior cruciate ligament (ACL) deficiency
Varus deformity of 5 degrees
Outerbridge grade II chondromalacia of the patella

Correct Answer: Anterior cruciate ligament (ACL) deficiency

Explanation:

DISCUSSION: UKA prostheses cannot substitute for an absent ACL, and if arthroplasty is indicated, these patients should receive a total knee arthroplasty rather than a UKA. Age is not an absolute contraindication, and the procedure has been advocated for young patients as well as older patients if they meet the appropriate indications for an arthroplasty. Varus deformities of the mechanical axis of up to 10 degrees generally are not a contraindication to unicompartmental arthroplasty, as long as the knee can be properly balanced at the time of surgery. Modest chondromalacia of the patellofemoral joint, especially if asymptomatic, is not a contraindication to UKA.
REFERENCES: Lotke PA (ed): Knee Arthroplasty: Master Techniques in Orthopaedic Surgery. New York, NY, Raven Press, 1995, pp 275-293.
Insall JN, Windsor RE, Scott WN, et al (eds): Surgery of the Knee, ed 2. New York, NY, Churchill Livingstone, 1993, pp 805-814.
Tabor OB Jr, Tabor OB: Unicompartmental arthroplasty: A long-term follow-up study.
J Arthroplasty 1998;13:373-379.

Question 14:

Options:

hospital admission for IV antibiotics and observation.
an epidural steroid.
anterior diskectomy and fusion with autologous bone graft.
laminectomy for decompression and debridement.
laminectomy for decompression with an instrumented posterolateral fusion.

Correct Answer: laminectomy for decompression and debridement.

Explanation:

Question 15:

Familial (Leiden) thrombophilia is of importance in joint arthroplasty because of an abnormality in the clotting cascade. Which of the following statements best describes the condition?

Options:

It is a disease caused by an abnormality of platelets that leads to increased blood clotting.
It is a disease caused by an abnormality of vascular endothelium that leads to increased blood clotting.
It is a disease caused by an abnormality of hepatic metabolism that leads to decreased production of factor V and decreased blood clotting.
It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.
It is a familial, genetic disease that requires placement of a Greenfield filter in all individuals who have the abnormality, prior to surgery.

Correct Answer: It is a disease caused by an abnormality of factor V that leads to decreased inactivation of factor Va by activated protein C (aPC) and increased blood clotting.

Explanation:

Question 16:

In patients with suspected hepatitis C, which of the following tests is commonly used to confirm the diagnosis after a positive ELISA screening test?

Options:

Polymerase chain reaction (PCR)
Northern blot
Immunoblot assay
Microarray
Proteomics

Correct Answer: Immunoblot assay

Explanation:

Question 17:

What muscles are responsible for the most common deformity after antegrade intramedullary nailing for a subtrochanteric femur fracture?

Options:

Hip abductors and iliopsoas muscle
Hip internal rotators and iliopsoas muscle
Quadriceps and iliopsoas muscle
Hamstring and iliopsoas muscle
Quadriceps and hip adductors

Correct Answer: Hip abductors and iliopsoas muscle

Explanation:

Question 18:

Poor pre-injury cognitive function has been proven to increase mortality for which of the following injuries?

Options:

Proximal humerus fracture
Distal radius fracture
Pelvic ring fracture
Hip fracture
Distal femur fracture

Correct Answer: Proximal humerus fracture

Explanation:

Question 19:

Which of the following radiographic views best depicts a Hill-Sachs defect?

Options:

Outlet
True AP
Serendipity
Stryker notch
Zanca

Correct Answer: Stryker notch

Explanation:

Question 20:

Options:

Calcified transverse scapular ligament
Parsonage-Turner syndrome
Spinoglenoid notch cyst
Quadrilateral space syndrome

Correct Answer: Spinoglenoid notch cyst

Explanation:

Question 21:

Options:

recurrent buckling with a probable meniscal tear.
limitation of motion with a delay in recovery.
a full return to activity with no limitations.
an improvement in overall performance.
an uneventful completion of the soccer season.

Correct Answer: recurrent buckling with a probable meniscal tear.

Explanation:

Question 22:

Options:

Bed rest for 6 weeks, followed by a thoracolumbosacral orthosis (TLSO) until the fracture is healed
TLSO and or body cast for 3 to 6 months with mobilization when comfortable
Posterior spinal fusion and instrumentation
Anterior decompression with spinal fusion and instrumentation
Anterior decompression and anterior-posterior spinal fusion and instrumentation

Correct Answer: TLSO and or body cast for 3 to 6 months with mobilization when comfortable

Explanation:

Question 23:

Options:

Anterior ulnar nerve transposition
Cortisone injection
Nighttime elbow extension splinting
Medial collateral ligament reconstruction
Ulnar nerve decompression in situ

Correct Answer: Nighttime elbow extension splinting

Explanation:

DISCUSSION: The patient’s symptoms and examination findings are consistent with ulnar neuritis/cubital tunnel syndrome, most probably exacerbated by javelin throwing. The first step includes rest and extension splinting. Surgical intervention should only be considered after failure of nonsurgical management.
REFERENCES: Posner MA: Compressive neuropathies of the ulnar nerve at the elbow and wrist. Instr Course Lect 2000;49:305-317.
Omer GE, Spinner M, Van Beek AL (eds): Management of Peripheral Nerve Problems, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 65-69.

Question 24:

Figures 31a and 31b show the radiograph and MRI scan of an otherwise normal 3-month-old infant who has a spinal deformity. MRI reveals no intraspinal anomalies. What is the next step in management?

Options:

Posterior spinal fusion with instrumentation
Anterior-posterior hemiepiphysiodesis
Brace management
Cardiac and renal evaluation
Hemivertebrectomy and fusion

Correct Answer: Cardiac and renal evaluation

Explanation:

DISCUSSION: Congenital scoliosis in an infant warrants evaluation of the renal, cardiac, and neurologic systems because frequently there is concurrent pathology. Progression in this instance is possible but not certain; therefore, progression must be documented prior to any surgical intervention. Close observation with serial radiographs every 4 to 6 months is appropriate. All of the surgical options listed may be reasonable choices in the future, but cardiac evaluation is the most important issue at this time.
REFERENCES: Basu PS, Elsebaie H, Noordeen MH: Congenital spinal deformity:
A comprehensive assessment at presentation. Spine 2002;27:2255-2259.
Hedequist D, Emans J: Congenital scoliosis. J Am Acad Orthop Surg 2004;12:266-275.

Question 25:

In recurrent posterior shoulder instability, what is the recommended approach to the posterior capsule?

Options:

A teres minor-splitting approach
An infraspinatus-splitting approach
Between the infraspinatus and teres minor
Between the supraspinatus and infraspinatus
In the rotator interval

Correct Answer: An infraspinatus-splitting approach

Explanation:

DISCUSSION: Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.
REFERENCES: Dreese J, D’Alessandro D: Posterior capsulorrhaphy through infraspinatus split for posterior instability. Tech Shoulder Elbow Surg 2005;6:199-207.
Shaffer BS, Conway J, Jobe FW, et al: Infraspinatus muscle-splitting incision in posterior shoulder surgery: An anatomic and electromyographic study. Am J Sports Med 1994;22:113-120.
Fuchs B, Jost B, Gerber C: Posterior-inferior capsular shift for the treatment of recurrent voluntary posterior subluxation of the shoulder. J Bone Joint Surg Am 2000;82:16-25.

Question 26:

Options:

Patellar clunk syndrome
Flexion gap instability
Polyethylene wear
Femoral component malrotation

Correct Answer: Patellar clunk syndrome

Explanation:

Question 27:

A 10-month-old boy has an untreated developmental hip dislocation.

Options:

Sclerosis of the proximal femoral epiphysis with subchondral lucency
Abnormal femoral head-neck junction offset
Widening of the proximal femoral physis with normal femoral head-neck junction offset
Absence of the proximal femoral epiphysis secondary ossification center

Correct Answer: Absence of the proximal femoral epiphysis secondary ossification center

Explanation:

Question 28:

Options:

a base plate with an offset tibial stem attachment.
a bone ingrowth surface on the augment.
a nonstemmed tibial base plate.
allograft bone instead of metal augments.
bone cement to smooth the outline of the proximal medial tibia.

Correct Answer: a base plate with an offset tibial stem attachment.

Explanation:

DISCUSSION: The problem with this reconstruction is the medial protrusion of the base plate. The use of a base plate with an offset stem can prevent the protrusion and thus the impingement and pain. Allograft bone or smoothing the outline with cement would be just as prominent and likely to cause pain. An ingrowth surface may improve soft-tissue attachment but would still leave the implant protruding medially and likely to cause pain. A nonstemmed tibial base plate would lead to less medial protrusion but at the expense of a smaller area for load carriage on the proximal tibia.
REFERENCE: Gustke K: Cemented tibial stems are not requisite in revision. Orthopedics 2004;27:991-992.

Question 29:

Options:

Trapeziometacarpal arthrodesis
Osteotomy of the thumb metacarpal
Arthrotomy and joint debridement
Ligament reconstruction using one half of the flexor carpi radialis
Trapezium resection, tendon interposition, and reconstruction of the ligament

Correct Answer: Ligament reconstruction using one half of the flexor carpi radialis

Explanation:

Question 30:

A neurologic injury at T11-L2 with loss of bowel and bladder control is best described as what syndrome?

Options:

Anterior cord
Central cord
Posterior cord
Conus medullaris
Cauda equina

Correct Answer: Conus medullaris

Explanation:

Question 31:

- Which of the following conditions is most likely inherited as an autosomal dominant trait?

Options:

Syndactyly
Macrodactyly
Camptodactyly
Preaxial polydactyly
Postaxial polydactyly

Correct Answer: Postaxial polydactyly

Explanation:

Question 32:

Options:

Range of motion
Infraspinatus strength
Activity level
Quality of the subscapularis

Correct Answer: Quality of the subscapularis

Explanation:

Question 33:

What is the most common maxillofacial/dental injury in ice hockey?

Options:

Temporomandibular
Lip laceration
Tooth avulsion
Crown fracture
Mandible fracture

Correct Answer: Crown fracture

Explanation:

Question 34:

Options:

Osteoporosis
Hallux valgus deformity
Hallux rigidus
A relatively long second metatarsal

Correct Answer: A relatively long second metatarsal

Explanation:

Question 35:

Options:

Sickle-cell crisis
Heat exhaustion
Heatstroke
Dehydration

Correct Answer: Heatstroke

Explanation:

Question 36:

Options:

Similar loss of elbow motion
Greater loss of elbow extension
Higher rate of varus malalignment
Higher rate of functionally limiting malalignment
Significantly better shoulder motion

Correct Answer: Similar loss of elbow motion

Explanation:

Question 37:

Which of the following muscles has dual innervation?

Options:

Pronator teres
Flexor digitorum superificialis
Coracobrachialis
Latissimus dorsi
Brachialis

Correct Answer: Brachialis

Explanation:

Question 38:

Which of the following postoperative rehabilitation techniques causes minimal rotator cuff muscle activation? Review Topic

Options:

Active forward flexion
Passive forward flexion
Active-assisted forward flexion
Overhead pulley-assisted passive forward flexion
Isometric strengthening

Correct Answer: Passive forward flexion

Explanation:

Question 39:

- What is the usual mechanism of injury for the fracture shown in Figures 49a and 49b?

Options:

bending
axial loading
high-speed rotation
direct impact from anteromedial
crush from anteromedial to posterolateral

Correct Answer: axial loading

Explanation:

Question 40:

Options:

Hardware migration is more likely than with acromioclavicular pinning.
Failure of fixation is usually at the level of the clavicle.
Hardware removal is avoided to prevent late displacement.
Neurologic injury most likely involves the axilllary nerve.
Acromioclavicular arthritis is more likely than with nonsurgical management.

Correct Answer: Acromioclavicular arthritis is more likely than with nonsurgical management.

Explanation:

Question 41:

Options:

Long radiolunate ligament
Radioscaphocapitate ligament
Dorsal radiocarpal ligament
Dorsal intercarpal ligament

Correct Answer: Radioscaphocapitate ligament

Explanation:

EXPLANATION:
The radioscaphocapitate ligament must be preserved in cases of proximal row carpectomy or scaphoidectomy with four-corner fusion. Failure to do so can result in ulnar translocation of the carpus. The attachment of the long radiolunate ligament to the lunate is compromised in proximal row carpectomy, although it is left intact in scaphoidectomy with four-corner fusion. Preservation of the dorsal radiocarpal ligament through a limited arthrotomy is advocated by Ozyurekoglu and Turker as a method of preserving the blood and nerve supply of the carpus, but this technique has not been proven to be
required. The authors did cut through the dorsal intercarpal ligament in their exposure.

Question 42:

Options:

above-knee amputation.
preoperative chemotherapy, wide resection of the distal femur, and reconstruction.
preoperative chemotherapy and above-knee amputation.
wide resection of the distal femur and subsequent reconstruction, followed by chemotherapy.
curettage and placement of methylmethacrylate.

Correct Answer: preoperative chemotherapy, wide resection of the distal femur, and reconstruction.

Explanation:

Question 43:

Options:

High tibial osteotomy
Total knee replacement
Unicondylar knee replacement
Arthroscopic partial meniscectomy

Correct Answer: Total knee replacement

Explanation:

Question 44:

Options:

Penicillin
Sulfur
Shellfish
Chicken or eggs
Lidocaine

Correct Answer: Chicken or eggs

Explanation:

Question 45:

Which factor increases the success rate associated with all-inside lateral meniscal repair?

Options:

Concomitant anterior cruciate ligament (ACL) reconstruction
Concomitant medial meniscus repair
Older patient age
Varus knee alignment

Correct Answer: Concomitant anterior cruciate ligament (ACL) reconstruction

Explanation:

Question 46:

Options:

Elevate leg on pillows
Administer IV morphine
Observation of the patient
Bivalve and spread the cast
Apply ice to the lower extremity

Correct Answer: Administer IV morphine

Explanation:

The patient appears to have some indications of a compartment syndrome: increasing pain and signs of nerve compression. Tibia fractures also should heighten the suspicion for a compartment syndrome. Two basic mechanisms of compartment syndrome are that an increase in volume occurs in an enclosed space or there is a decrease in size of the space. In this situation, both are likely occurring; post-fracture swelling is occurring within a closed space and if a cast is in place that may constrict the space even more. One way to increase the available space for swelling would be to bivalve and spread the cast. If the extremity has been casted, then it is vitally important that the cast is bivalved and the surrounding soft dressings under the cast be removed so that all external compression of the compartment has been eliminated. In the face of compartment syndrome, elevation of the limb, masking the pain with morphine, application of ice, or observation alone are all inappropriate.
(SBQ12TR.88) When evaluating a fracture dislocation of the elbow, a varus and posteromedial rotation mechanism of injury typically results in what injury pattern?
A fracture of the radial head requiring ORIF
A highly comminuted radial head fracture requiring radial head arthroplasty or resection
An MCL injury requiring repair
A type I avulsion fracture of the coronoid
An anteromedial coronoid fracture
A varus and posteromedial rotation mechanism of injury typically results in a fracture of the anteromedial facet of the coronoid which frequently requires reduction and fixation to restore stability.
A varus and posteromedial mechanism of injury about the elbow presents with an injury pattern distinctly different from other injury patterns. A key part of treating this injury pattern is recognizing a fracture of the anteromedial facet of the coronoid, which often requires reduction and fixation to restore stability about the elbow. It is important to recognize this during preoperative planning since this injury typically requires a medial approach.
Steinman presents a review article describing coronoid fracture patterns and their mechanisms of injury.
Doornberg and Ring present a level 4 review showing that coronoid fracture patterns and their required treatments are predictable based on mechanism of injury. Varus and posteromedial mechanisms were found to reliably create a fracture of the anteromedial facet of the coronoid, and were associated with sparing of the MCL and radial head.
Doornberg and Ring also presented a Level 3 review of anteromedial facet cornoid fractures. They found that they could not be adequately visualized and treated from a lateral approach, and that they typically required reduction and fixation to restore adequate stability to the elbow. This stresses the importance of recognizing this injury pattern during preoperative planning.
Illustrations A and B are AP and lateral radiographs of an elbow following a varus/posteromedial injury with an anteromedial coronoid facet fracture. Illustration C is a diagram demonstrating fracture lines that create an anteromedial facet fracture fragment. This fracture can be subclassified into three subtypes [anteromedial rim (a), rim plus tip (b), and rim and tip plus the sublime tubercle (c)]
Incorrect answers:
(SBQ12TR.78) A 67-year-old female patient presents with increasing right hip/thigh pain over the past three months, which is now recalcitrant to anti-inflammatories. There is no history of trauma or constitutional symptoms. Her past medical history consists of hypertension, coronary artery disease, osteoporosis and gastric reflux. Physical examination reveals mild pain at the extremes of range of motion of the hip and a painful right sided limp. A radiograph of the right hip is seen in Figure A. What would be the most appropriate treatment for this patient at this time?
Review
Topic
Observation only
Referral to physiotherapy
MRI spine and hip
Total hip arthroplasty
Intramedullary femoral nail
This osteoporotic female patient is presenting with subtrochanteric lateral cortical thickening and hip pain. This is consistent with an insufficiency fracture of the femur secondary to use of bisphosphonate medication for treatment of osteoporosis. The most appropriate treatment would be intramedullary femoral nail fixation.
Bisphosphonate medications have been shown to be associated with atypical (subtrochanteric) femur fractures. These patients often have prodromal hip pain and lateral cortical thickening on radiographs prior to fracture. In addition, there has shown to be a significantly increased risk of fracture in the presence of the “dreaded black line” that occurs at the site of thickening.
Lenart et al. examined a case series of patients using bisphosphonates for the treatment of osteoporosis. They identified 15 postmenopausal women who had been receiving alendronate for a mean (±SD) of 5.4±2.7 years and who presented with atypical low-energy fractures. Cortical thickening was present in the contralateral femur in all the patients with this pattern.
Goh et al. retrospectively reviewed patients who had presented with a low-energy subtrochanteric fractures. They identified 13 women of whom nine were on long-term alendronate therapy. Five of these nine patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur.
Figure A shows a right hip radiograph with subtrochanteric lateral cortical thickening. There is mild arthritic changes in the hip. Illustration A shows a bone scan and radiographs of subtrochanteric lateral cortical thickening that resulted in fracture.
Incorrect Answers

Question 47:

What artery provides the only direct vascularizaton to both the intraneural and extraneural blood supply of the ulnar nerve just proximal to the cubital tunnel?

Options:

Superior ulnar collateral
Inferior ulnar collateral
Posterior ulnar recurrent
Brachial
Ulnar

Correct Answer: Inferior ulnar collateral

Explanation:

Question 48:

Options:

Artery medial, then lateral
Artery lateral, then medial
Artery always medial
Artery always lateral
Artery always deep

Correct Answer: Artery medial, then lateral

Explanation:

DISCUSSION: At the ankle level, the anterior tibial artery lies medial to the EHL tendon. The artery becomes the dorsalis pedis after crossing onto the dorsum of the foot. At this point, the artery lies lateral to the tendon.
REFERENCES: Resch S: Functional anatomy and topography of the foot and ankle, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 1, pp 25-49.
Sarrafian SK: Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993.

Question 49:

What is the most common physical finding in myelopathic patients? Review Topic

Options:

Babinski sign
Hoffman sign
Hyperreflexia
Clonus
Ataxic gait

Correct Answer: Hoffman sign

Explanation:

Question 50:

Options:

Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.
Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.
Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.
Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.
Place blocking screws lateral and anterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Correct Answer: Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Explanation:

Question 51:

Options:

bone scan results returning to normal.
a decline in intensity on serial bone scans.
the serum levels of alkaline phosphatase measured over time.
the level of serum calcium-phosphorus product.
the time since injury and evidence of bone maturation on plain radiographs.

Correct Answer: the time since injury and evidence of bone maturation on plain radiographs.

Explanation:

Question 52:

A “p value” of 4% (p=0.04) indicates that the

Options:

hypothesis is incorrect or invalid
interobserver error rate is 4%.
Standard deviation is 4% higher or lower than the mean.
Sample size is 4% larger than required to be clinically significant.
Probability that the differences noted between two study groups were due to chance alone is 4%.

Correct Answer: Probability that the differences noted between two study groups were due to chance alone is 4%.

Explanation:

Question 53:

Which of the following statements best describes the instantaneous axis of rotation (IAR) for the functional spinal unit? Review Topic

Options:

The IAR is calculated by movement around six different axes.
The IAR consists of potential movements or 12 degrees of freedom.
The IAR is fixed and consistent and is the axis about which each vertebral segment rotates.
The IAR can be derived from AP and lateral radiographs.
Degenerative disease, fractures, and ligamentous injuries can affect the IAR.

Correct Answer: Degenerative disease, fractures, and ligamentous injuries can affect the IAR.

Explanation:

Question 54:

Options:

Endoscopy
Gastrostomy
Colonoscopy
Laparotomy

Correct Answer: Colonoscopy

Explanation:

Question 55:

What type of cementless femoral fixation results in the highest rate of distal femoral osteolysis?

Options:

Tapered circumferential proximally porous-coated stem
Hydroxyapatite-coated tapered circumferential proximally porous-coated stem
Straight circumferential fully porous-coated stem
Straight modular circumferential proximally porous-coated sleeve and distal fluted stem
Noncircumferential proximally porous-coated stem

Correct Answer: Noncircumferential proximally porous-coated stem

Explanation:

Question 56:

A 47-year-old man has an acute swollen, red, painful first metatarsophalangeal joint. He denies any history of similar symptoms. What is the first step in evaluation?

Options:

Serum uric acid level studies and administration of indomethacin
Administration of colchicine
Administration of allopurinol
Aspiration with evaluation of crystals, cell count, and culture
Aspiration with evaluation of crystals and steroid injection

Correct Answer: Aspiration with evaluation of crystals, cell count, and culture

Explanation:

Question 57:

Options:

Bulky gauze dressings with no compression of the traumatized tissues and early non-weight-bearing ambulation
Bulky gauze dressings with snug compression of the residual limb and early non-weight-bearing ambulation
Immediate intraoperative prosthetic fitting with a vacuum-formed prosthetic limb, followed by immediate weight bearing
Rigid plaster dressing, a cast change at 5 to 7 days, and partial weight bearing with an attached pylon when the wound shows signs of healing without infection
Compression dressing and delayed application of a weight-bearing pylon until the sutures are removed and the wound is well healed

Correct Answer: Rigid plaster dressing, a cast change at 5 to 7 days, and partial weight bearing with an attached pylon when the wound shows signs of healing without infection

Explanation:

Question 58:

Figure 37 shows a coronal T2-weighted MRI scan. What is the name of the labeled torn structure?

Options:

Brachialis tendon
Biceps tendon
Flexor/pronator origin
Medial collateral ligament (MCL)
Lateral collateral ligament (LCL)

Correct Answer: Lateral collateral ligament (LCL)

Explanation:

DISCUSSION: The labeled structure is the LCL, and it is avulsed from the lateral humeral epicondyle. This is the most common site of injury for the LCL. The biceps and brachialis tendon insertions are not well visualized in this section. The MCL and flexor/pronator origin
are intact.
REFERENCES: Potter HG, Weiland AJ, Schatz JA, et al: Posterolateral rotatory instability of the elbow: Usefulness of MR imaging in diagnosis. Radiology 1997;204:185-189.
King JC, Spencer EE: Lateral ligamentous instability: Techniques of repair and reconstruction. Techniques in Orthopaedics 2000;8:93-104.

Question 59:

A 23-year-old woman has had vague left knee pain for the past 6 months. A radiograph and CT scan are shown in Figures 50a and 50b. What is the most likely diagnosis?

Options:

Myositis ossificans
Osteochondroma
Parosteal osteosarcoma
Dedifferentiated chondrosarcoma
Tumoral calcinosis

Correct Answer: Parosteal osteosarcoma

Explanation:

Question 60:

Options:

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

Correct Answer: subtalar distraction bone block arthrodesis.

Explanation:

Question 61:

A 5-month-old girl with arthrogryposis has a limb-length discrepancy. Examination and radiographs reveal unilateral hip dislocation. Management should consist of

Options:

a Pavlik harness.
observation.
closed reduction and a spica cast.
open reduction and femoral shortening.
open reduction.

Correct Answer: open reduction.

Explanation:

Question 62:

What factor is associated with a high risk of developing pseudotumors after metal-on-metal hip resurfacing?

Options:

Large-diameter components
Age 40 or older for men
Age 40 or younger for women
Diagnosis of primary osteoarthritis

Correct Answer: Age 40 or younger for women

Explanation:

The recent experience of a large clinical cohort revealed the most likely
risk factors
as being
female
gender
,
age younger than 40
,
small components
, and a
diagnosis of hip dysplasia causing osteoarthritis
. Failure was least likely among men and after procedures involving larger components. These data have prompted some authors to caution against using metal-on-metal hip resurfacing in women and to primarily target candidates who are men younger than age 50. Small components may be more prone to failure because of malpositioning and edge loading, which have been noted to be more common in dysplasia cases.

Question 63:

Options:

Surgery on the wrong patient
Surgery on the wrong side
Incorrect procedure performed
Intraoperative death
Surgery on the wrong level

Correct Answer: Surgery on the wrong level

Explanation:

DISCUSSION: Patient safety and prevention of medical errors is a major focus of recent national advocacy groups. Analysis has shown that the most common sentinel event in spine surgery is surgery on the wrong level. Therefore, it is recommended that every patient have the surgical site signed, the level of surgery marked intraoperatively, and a radiograph taken. Surgery on the wrong level is most likely to occur in single-level decompressive procedures.
REFERENCES: Wong DA, Watters WC III: To err is human: Quality and safety issues in spine care. Spine 2007;32:S2-S8.
Wong DA: Spinal surgery and patient safety: A systems approach. J Am Acad Orthop Surg 2006;14:226-232.

Question 64:

Options:

Neurosurgeon
Ophthalmologist
Oncologist
Otolaryngologist
Urologist

Correct Answer: Ophthalmologist

Explanation:

Question 65:

Options:

Facet joint injection and lumbosacral orthosis
Posterior stabilization
Revision arthroplasty via far lateral approach
Revision to arthrodesis via far lateral approach
Revision to arthrodesis via retroperitoneal approach

Correct Answer: Facet joint injection and lumbosacral orthosis

Explanation:

Question 66:

Which of the following vertebrae has the smallest pedicle isthmic width in a nondeformity patient?

Options:

Correct Answer: L1

Explanation:

DISCUSSION: The smallest pedicle isthmic width is at L1, whereas T12 has the largest pedicle width in the upper lumbar and lower thoracic spine. Although smaller in diameter than T12, both T10 and T11 have larger pedicle widths than L1.
REFERENCE: Ofiram E, Polly DW, Gilbert TJ Jr, et al: Is it safe to place pedicle screws in the lower thoracic spine than in the upper lumbar spine? Spine 2007;32:49-54.

Question 67:

Options:

Transfer metatarsalgia
Morton’s neuroma
Metatarsal stress fracture
Freiberg’s infraction
Metatarsophalangeal synovitis

Correct Answer: Metatarsal stress fracture

Explanation:

Question 68:

Options:

use of a sling with no range-of-motion exercises until the condition is stable.
use of a sling and passive range-of-motion exercises within the limits of the repair.
no sling and supine passive range-of-motion exercises.
an internal rotation brace holding the arm at the side.
an external rotation brace holding the arm at the side.

Correct Answer: an external rotation brace holding the arm at the side.

Explanation:

Question 69:

Where is the watershed zone for tarsal navicular vascularity?

Options:

Medial one third
Central one third
Lateral one third
Tuberosity
Inferior pole

Correct Answer: Central one third

Explanation:

DISCUSSION: The central one third has been established as the watershed zone by angiographic studies, and has been borne out in clinical conditions involving the navicular, such as stress fractures and osteonecrosis. These findings account for the susceptibility to injury at this level.
REFERENCES: Nunley JA, Pfeffer GB, Sanders RW, et al (eds): Advanced Reconstruction: Foot and Ankle. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004,
pp 239-242.
Sarrafian
SK
: Anatomy of the Foot and Ankle. Philadelphia, PA, JB Lippincott, 1983,
pp 299-302.

Question 70:

Options:

observation only.
nonsteroidal anti-inflammatory drugs and protected weight bearing.
irradiation to the affected area.
surgical excision.
surgical excision and postoperative irradiation.

Correct Answer: surgical excision and postoperative irradiation.

Explanation:

Question 71:

Options:

physical therapy and nonsteroidal anti-inflammatory drugs for 4 to 6 weeks.
physical therapy, nonsteroidal anti-inflammatory drugs for 4 to 6 weeks, and methylprednisolone.
epidural steroid injections.
elective surgery.
urgent surgery.

Correct Answer: urgent surgery.

Explanation:

Question 72:

Options:

anterior translation of the humeral head.
loss of external rotation.
excessive tightening of the biceps tendon.
superior migration of the humeral head.
no excessive changes

Correct Answer: loss of external rotation.

Explanation:

If the Buford complex is mistakenly reattached to the neck of the glenoid, severe painful restriction of external rotation will occur.

Question 73:

Which of the following is considered the most appropriate indication for conversion of a hip fusion to total hip arthroplasty?

Options:

Moderate arthritis of the ipsilateral knee
Progressive arthritis of the contralateral hip
Severe disabling back pain
Limb-length discrepancy
Increased hip motion

Correct Answer: Severe disabling back pain

Explanation:

Question 74:

Bridge plating of the olecranon is MOST appropriate in which of the following clinical scenarios?

Options:

Fixation of an olecranon osteotomy used for distal humerus surgery in a 24-year-old male
Simple transverse olecranon fracture in 33-year-old female
Comminuted olecranon fracture in 45-year-old male
Severely comminuted proximal olecranon fracture in an osteoporotic 91-year-old female
Aphophyseal elbow fracture in 6-year-old male

Correct Answer: Fixation of an olecranon osteotomy used for distal humerus surgery in a 24-year-old male

Explanation:

Question 75:

Which of the following classes of antibiotics works by binding to the 30S-ribosomal subunit?

Options:

Aminoglycosides
Penicillins
Rifampin
Macrolides
Quinolones

Correct Answer: Penicillins

Explanation:

Question 76:

The posterior cord of the brachial plexus terminates into what two main branches?

Options:

Lateral and medial pectorals
Lateral pectoral and suprascapular
Radial and axillary nerves
Musculocutaneous and the lateral root of the median nerve
Ulnar and medial roots of the median nerve

Correct Answer: Radial and axillary nerves

Explanation:

Question 77:

A 57-year-old woman experiences pain 1 year after total knee arthroplasty (TKA). She reports sharp anterior pain and a painful catching sensation that is aggravated by rising from a chair or climbing stairs. Physical examination reveals a mild effusion and a range of motion of 2° to 130°, with patellar crepitus. The symptoms are reproduced by resisted knee extension. Radiographs show a well-aligned posterior- stabilized TKA without evidence of component loosening. What is the most likely cause of this patient's pain?

Options:

Patellar clunk syndrome
Flexion gap instability
Polyethylene wear
Femoral component malrotation

Correct Answer: Patellar clunk syndrome

Explanation:

Question 78:

What is the most significant benefit of percutaneous transforaminal lumbar interbody fusion (TLIF) vs open posterior lumbar interbody fusion (PLIF)?

Options:

Preservation of the paraspinal muscle sleeve
Higher fusion rate
More measurable intraoperative blood loss
Improved ability to evacuate the disk space

Correct Answer: Preservation of the paraspinal muscle sleeve

Explanation:

DISCUSSION
Humphreys and associates in a retrospective review of TLIF vs PLIF found fusion rates, surgical time, and length of hospital stay were similar with both procedures. The only benefits associated with TLIF were less blood loss and preservation of the paraspinal muscle sleeve. Manos and associates in a cadaver study found no difference in the volume of disk material evacuated or the area of endplate exposed in either procedure.
RECOMMENDED READINGS
Humphreys SC, Hodges SD, Patwardhan AG, Eck JC, Murphy RB, Covington LA. Comparison of posterior and transforaminal approaches to lumbar interbody fusion. Spine (Phila Pa 1976). 2001 Mar 1;26(5):567-71. PubMed PMID: 11242386.
View Abstract at PubMed
Manos R, Sukovich W, Weistroffer J: Transforaminal lumbar interbody fusion: Minimally invasive versus open disc excision and endplate preparation. Presented at the 12th International Meeting of Advanced Spine Techniques, Banff, Alberta, Canada, July 7-9, 2005.

Question 79:

Following irrigation and debridement, what is the preferred method of fixation for a displaced open tibia fracture with a 16-cm clean wound?

Options:

Closed reduction and cast immobilization
Uniplanar external fixation
Open reduction and internal fixation with a dynamic compression plate
Unreamed intramedullary rod
Multiple plane external fixator

Correct Answer: Unreamed intramedullary rod

Explanation:

Question 80:

Benign Ethnic Neutropenia is more common in males.

Options:

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?
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: Acute knee injuries requiring operative treatment

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:
The perioperative use of which medication has been shown to increase the risk of post-operative infection following orthopaedic procedures in patients with rheumatoid arthritis (RA)?
Naproxen
Leflunomide
Sulfasalazine
Etanercept
Aspirin
Of the medications listed, only etanercept has been shown to increase the risk of post- operative infection following orthopaedic procedures in patients with RA.
Etanercept is a TNF-alpha antagonist with a short half-life that is administered once or twice weekly in patients with RA. Since TNF-alpha plays a central role in the pathogenesis of RA and is instrumental in causing joint destruction, the inhibition of this molecule has shown excellent results in controlling disease. The most powered study on TNF-alpha inhibitor use in the perioperative period following an orthopaedic procedures demonstrated a significant increase in
post-operative infection.
Howe et al. review the medical management of patients with RA who underwent orthopaedic procedures. They state that while there is conflicting information regarding TNF-alpha antagonists, they recommend holding them prior to major orthopaedic interventions.
Giles et al. review 91 patients with rheumatoid arthritis who underwent an orthopaedic procedure. They found TNF-alpha inhibitor therapy to be significantly associated with the development of a serious postoperative infection (p=.041)
Perhala et al. review 61 patients with RA who were treated with methotrexate during the perioperative period surrounding a total joint arthroplasty. They
failed to find a significant increase in complications in this patient group, stating the perioperative use of methotrexate does not affect wound healing or increase the likelihood of periprosthetic infection.
Illustration A shows the site of action of TNA-alpha inhibitors in the RA pathway.
Incorrect Answers:
Communication breakdown is the leading cause of which of the following?
Delayed diagnoses
Medication errors
Surgical site infections
1 and 2
All of the above
Communication failures are the leading cause of wrong side surgeries, medication errors and diagnostic delays.
Poor communication sets up environments in which medical errors can take place. Per the Joint Commission, medical errors may be the among the top 10 causes of death in the United States. Establishing open lines of communication is critical to reduce the risk of error and enhance patient safety.
Gandhi et al. designed a framework to study missed or delayed diagnoses and their causes. The most significant factors contributing to errors were poor handoffs, failures in judgment, failures in memory and failures in knowledge.
O’Daniel et al. review the importance of professional communication and collaborative team efforts. They note that patient safety is at risk when poor communication is in place. The leading cause for medication errors, treatment delays and wrong-site surgeries is communication failure.
Illustration A shows the leading causes of death in the United States. This includes “preventable errors” as a cause.
Incorrect Answers:
treatment, medication errors and wrong side surgery
Which of the following is true regarding osteoprotegerin (OPG)?
It is secreted by osteoclasts
It increases bone resorption
Binds to prostoglandin E2 before stimulating osteoclasts
Osteoprotegerin knock-out mice develop osteopetrosis
Binds to and sequesters RANKL
Osteoprotegerin is a decoy receptor for RANKL. Binding to RANKL causes decreased production of osteoclasts by inhibiting the differentiation of osteoclast precursors.
Bone resporption/remodeling is a complex process regulated by a large variety of molecules. Molecules that have shown to inhibit osteoclasts include OPG, calcitonin, estrogen, TGF-B, and IL-10. Corticosteroids have been shown to decrease production of OPG, thereby enhancing osteoclast formation and longevity. Prolia, or denosumab, is a newly approved drug used to treat osteoporosis and has a mechanism of action similar to osteoprotegerin
(inhibits binding of RANKL to RANK).
Boyle et al. review osteoclast differentiation and activation. The authors state that targeted disruption of OPG causes increased osteoclastogenesis and/or activation resulting in osteopenia.
Illustration A shows how OPG binds to RANKL inhibiting the stimulation of osteoclasts.
Incorrect Answers:
A 55-year-old woman has T-score -2.0 at the femoral neck. According to the World Health Organization Fracture Risk Assessment Tool (FRAX), she has a ten- year probability of sustaining a hip fracture of 1.5% and a ten-year probability of sustaining a major osteoporotic fracture of 8.9%. Which of the following statements is true regarding her antiresorptive therapy management?
Antiresorptive therapy should be started based on her T-score
Antiresorptive therapy should be started based on her risk of hip fracture alone
Antiresorptive therapy should be started based on her risk of major osteoporotic fracture alone
Antiresorptive therapy should not be started
Antiresorptive therapy should be started based on her risks of both hip fracture and major osteoporotic fracture
This patient has osteopenia. Assessment by FRAX shows that ten-year risk of hip fracture is less than 3% and her ten-year risk of major osteoporosis- related fracture is less than 20%. Therefore, antiresorptive therapy is not indicated at this time.
According to the 2008 National Osteoporosis Foundation guidelines, pharmacologic treatment for osteoporosis should be considered if patients are
postmenopausal women or men greater than 50 years old AND meet one of the following criteria: (1) they have a prior hip or vertebral fracture, (2) they have a T score -2.5 or less at the femoral neck or spine, (3) they have a T score between -1.0 and -2.5 at the femoral neck or spine AND a 10-year risk of hip fracture greater than 3% or 10-year risk of major osteoporosis-related fracture greater than 20%.
FRAX (World Health Organization Fracture Risk Assessment Tool) calculates
year risk of fracture based on the following variables: age, sex, race, height, weight, BMI, history of fragility fracture, parental history of hip fracture, use of oral glucocorticoids, secondary osteoporosis and alcohol use to calculate 10-year risk of fracture.
Unnanuntana et al. reviewed the assessment of fracture risk. Besides FRAX score and T-score, they discussed biochemical markers of bone formation and resorption, which are useful for monitoring the efficacy of antiresorptive / anabolic therapy, and may help identify patients at high risk for fracture.
Ekman et al. reviewed the role of the orthopaedic surgeon in minimizing mortality and morbidity associated with fragility fractures. The surgeon should consider prescribing appropriate medications, physical therapy, assessing fall risk and preventing falls and changing lifestyle factors (exercise, smoking and alcohol).
Illustration A shows the FRAX online tool (
http://www.shef.ac.uk/FRAX/tool.aspx?country
=
=9).
Illustration B shows the
clinical risk factors considered in FRAX calculation.
Incorrect Answers:
A 32-year-old runner sustains a trimalleolar left ankle fracture. She undergoes open reduction and internal fixation and is kept non- weightbearing after surgery. At 2 months, what changes will occur in the articular cartilage of both her knees as a result of her current weightbearing regimen?
Cartilage thickening in the left (ipsilateral) knee and no change in cartilage thickness in the right (contralateral) knee
Cartilage thinning in both knees
Cartilage thinning in the left (ipsilateral) knee and no change in cartilage thickness in the right (contralateral) knee
Cartilage thinning in the left (ipsilateral) knee and increased cartilage thickness in the right (contralateral) knee
Increased cartilage thickness in both knees
After a period of off-loading, the off-loaded limb will experience cartilage thinning. The contralateral limb will not demonstrate any cartilage changes.
Physiologic loading of cartilage increases proteoglycan synthesis and cell proliferation and is chondroprotective. Joint immobilization leads to cartilage thinning, tissue softening, and reduced proteoglycan content, leading to cartilage erosion. Joint overuse leads to cartilage damage (in vitro only).
Hinterwimmer et al. examined cartilage atrophy after partial load bearing
using quantitative MRI. They found cartilage thinning in all knee compartments (greatest thinning, medial tibia; least thinning, patella). There was no change in cartilage morphology in the contralateral knee.
Sun reviewed the relationship between mechanical loading and cartilage degeneration. In OA, cartilage breakdown occurs at the articular surface, and is then fueled by synovial proteases and cytokines. In RA, synovial cells and macrophages are the source of degradative enzymes and incite cartilage destruction.
Milward-Sadler et al. examined mRNA levels following mechanical stimulation in normal and osteoarthritic chondrocytes. Normal chondrocytes showed increased aggrecan mRNA and decreased matrix metalloproteinase 3 (MMP-3) mRNA after stimulation. This
chondroprotective response was absent in osteoarthritic chondrocytes.
Illustration A shows pro- and anti-inflammatory mechanisms of mechanical loading on chondrocytes. Underloading and overloading induce cartilage damage through pathways involving the upregulation of MMPs and ADAMTSs (ADAMTS, a disintegrin and metalloproteinase with thrombospondin motifs, or aggrecanase). Physiological loading blocks these increases.
Incorrect Answers:
A morbidly obese 40-year-old man is scheduled to undergo hemilaminectomy for resection of an painful osteoid osteoma of the T6 lamina. He is positioned prone on a Jackson table and localization is performed with intraoperative fluoroscopy prior to the start of the case. At close to the end of the case, intraoperative frozen section reveals only normal bone fragment from the resected lamina. A probe is placed and a cross-table lateral radiograph reveals that the T7 lamina was resected instead of T6. At this point, the surgeon should
do all of the following EXCEPT
Complete the surgery
Abort the case and obtain further imaging
Apologize to the patient and family
Formally document the error in the operative report
Inform the patient and family immediately after the operation
Fluoroscopic localization of the correct thoracic vertebra can be difficult in the obese
patient. Upon detection of wrong level surgery, he should not abort the case. Rather, he should perform the desired procedure at the correct site, and advise the patient and family upon completion.
Adverse events are inevitable. The correct action following wrong-site surgery is to perform the desired procedure at the correct site followed by frank and honest communication with the patient/family. Open, honest communication favorably affects patient behavior, health outcomes, patient satisfaction, and often reduces the incidence of medical professional liability actions. The
discussion should include a disclosure of known facts and an explanation as to the likely cause, as well as ongoing treatment, follow up care, and prognosis.
The AAOS Information Statement about Wrong Site Surgery identifies 3 treatment steps following discovery of an error during surgery under general anesthesia: Return the patient to his preoperative condition, perform the correct procedure at the correct site, and advise the patient and family of what occurred and the likely consequences, if any, of the wrong- site surgery.
The AAOS Information Statement on Communicating Adverse Events states that the surgeon has an ethical and professional obligation to disclose the error to the patient and/or family. Disclosure should include what happened, why it happened, health implications, and what measures are being instituted to prevent recurrences.
Incorrect Answers:
All of the following are Standards of Professionalism relating to interactions with industry for practicing orthopaedic surgeons EXCEPT:
Decline gifts from industry with a market value over $100 (unless they are medical textbooks or patient educational materials)
Disclose to the patient any financial arrangements with industry that relates to the patient's treatment
Accept no direct financial inducements from industry for utilizing a particular implant
Disclose any relationship with industry to colleagues who may be influenced by your work
Decline to participate in industry sponsored non-CME courses or
conferences
The AAOS has adopted the Standards of Professionalism (SOP). These SOP’s establish mandatory, minimum levels of acceptable conduct for fellows and members of the AAOS to engage in relationships with industry. There are 17 standards with relation to industry. Answer choice 5 is not a SOP as surgeons are allowed to participate in or consult in meetings that are conducive to the effective exchange of information. The SOP also stipulate that tuition, travel, and modest hospitality (including meals and receptions) are allowed to attend an industry-sponsored non-CME course.
A prospective randomized trial is conducted to test the efficacy of Vitamin C versus placebo in treating patients who develop chronic regional pain syndrome (CRPS) after distal radius fractures. At first follow-up, the rates of CRPS are 1% and 9% in the study and placebo group, respectively. Which statistical test is most appropriate to determine significance?
Single factor analysis of variance
Chi-square test
Student t-test
Mann-Whitney rank sum test
Wilcoxon rank sum test
In the study provided, we need to determine whether distributions of categorical variables differ from one another. The appropriate study is the chi- square test.
Data can be classified as numerical (continuous) or categorical (proportional). Responses to such questions as "What is your major?" or Do you own a car?" are categorical because they yield data such as "biology" or "no." In contrast, responses to such questions as "How tall are you?" or "What is your G.P.A.?" are numerical. When comparing two independent means from numeric data, a t-test is performed. However, if categorical data is being compared, the chi- square test will determine if the proportions are really different.
Kocher et al. review basic clinical epidemiology and biostatistics relevant to orthopaedic surgery. Amongst other things, they describe that data can be summarized in terms of measures of central tendency, such as mean, median, and mode, and in terms of measures of dispersion, such as range, standard deviation, and percentiles.
Illustration A shows an algorithm for determining which test to use for varying data. Incorrect Answers:
distributed.
A 35-year-old patient is involved in a motor vehicle accident and sustains multiple fractures including a closed comminuted proximal meta-diaphyseal tibia fracture. The surgeon is considering bridge plating the fracture using a minimally invasive approach. Which of the following is true regarding bridge plating?
A locked plate construct (locked screws) or hybrid construct (locked and non- locked screws) is necessary.
Periosteal stripping is performed through two incisions proximal and distal to the fracture.
Bridge plating is performed following direct reduction of the fracture.
AO Type A diaphyseal fractures are best treated with this technique.
Bridge plating with a long working length creates a flexible, axially stable construct.
In bridged plating, only the most proximal and distal screw holes are filled. This creates a flexible, axially stable construct.
Bridge plating is applicable to all long-bone fractures with complex fragmentation and where intramedullary nailing or conventional plate fixation is not suitable. The construct preserves the blood supply to the fracture fragments as the fracture site is undisturbed during the operative procedure. It provides RELATIVE stability, allowing for some motion at the fracture site, leading to callus formation and secondary bone healing. The construct is FLEXIBLE because of increased distance between the 2 screws closest to the fracture (long working length), allowing for stress distribution and permitting more motion at the fracture site. The construct is also AXIALLY STABLE because the plate acts as an extramedullary splint and resists axial compression.
Livani et al. advocate using an anterior or antero-lateral approach for minimally invasive plating of the humerus. They recommend that distal access is obtained first, allowing identification of the lateral antebrachial cutaneous nerve. For distal fractures, they recommend extending the plate down to the lateral column.
Apivatthakakul et al. defined minimally-invasive plate osteosynthesis (MIPO) danger zones from the lateral epicondyle. They found the musculocutaneous nerve averaged 18- 43% of the humeral length, the danger zone for the radial nerve averaged 36-59% of the humeral length, and the most dangerous screws that penetrated or touched the radial nerve lay 47-53% of the humeral length.
Illustration A shows a distal tibia fracture. Illustration B shows radiographs 5 months after bridge plating of this fracture. There is callus formation, characteristic of indirect bone healing.
periosteal blood supply is critical.
Which of the following components of bone is most responsible for compressive strength?
Type I collagen
Osteocalcin
Proteoglycans
Osteonectin
Osteopontin
Proteoglycans, in addition to calcium hydroxyapatite [Ca10(PO4)6(OH)2], are most responsible for providing compressive strength.
Bone is composed of both organic and inorganic components. Inorganic components include calcium hydroxyapatite and osteocalcium phosphate. Organic components include collagen, proteoglycans, matrix proteins, cytokines and growth factors. While Type I collagen is responsible for providing the tensile strength of bone, proteoglycans and calcium hydroxyapatite [Ca10(PO4)6(OH)2] are most responsible for providing compressive strength. Proteoglycans contain a core protein with various
numbers of covalently attached side chains of glycosaminoglycans. In addition to providing compressive strength, they are also responsible for binding growth factors and inhibiting mineralization.
Knothe et al. review the osteocyte. They discuss that osteocytes are the most abundant
cells in bone, are actively involved in maintaining the bony matrix, and may act as mechanosensors.
Illustration A shows a proteoglycan aggregate, which can form when individual molecules link onto a chain of hyaluronic acid.
Incorrect Answers:
A prospective, randomized controlled trial of 150 patients undergoing total hip arthroplasty is performed to test whether repair of the capsule during a posterior approach reduces post-operative dislocations in the first three months. The study found no difference in dislocation rate if the capsule was repaired versus not repaired (p =
.34). Subsequently, a multicenter follow-up study of 2000 patients showed that repairing the capsule led to a decreased dislocation rate
in the first three months (p = .03). Assuming the second study reflects reality, which of the following errors occurred in the first study?
Observer bias
Type-II error
Alpha error
Type-I error
Confounding error
In this situation, the null hypothesis was accepted when it should have been rejected.
This is a type-II error.
A study can have two types of errors. Type-I errors, or alpha errors, occur when the null hypothesis is rejected when it should have been accepted. The alpha level refers to the probability of a type-I error. By convention, the alpha level of significance is set at 0.05, which means that we accept the finding of a significant association if there is less than a one in twenty chance that the observed association was due to chance alone. Type-II errors, or beta errors, occur when the null hypothesis is accepted when it should be rejected. This
often occurs when studies are underpowered. In the example above, the null hypothesis is that repair of the capsule does not reduce dislocations within the first three months. Since the first study did not show a statistically significant difference, the null hypothesis was accepted. Since a more powered study showed that repair of the capsule does reduce dislocations, the null hypothesis should have been rejected in the initial study (if it was adequately powered).
Fosgate et al. review the importance of sample size calculations when performing research. They state that sample size ensures statistical significance if the subsequent data collection is perfectly consistent with the assumptions made for the sample size calculation (assuming power was set as
50% or greater).
Illustration A shows the difference between type-I and type-II errors. Video V is a lecture discussing statistical definition review of PPV, NPV, sensitivity and specificity.
Incorrect Answers:
that properly constructed studies attempt to avoid.
Which of the following is a potential cause of fretting corrosion?
The micromotion at the femoral head-neck junction in a modular total hip replacement
A stainless-steel cerclage wire is in contact with a titanium-alloy femoral stem
Friction between polyethylene liner and femoral head leading to osteolysis
The formation of pits within a stainless-steel plate and the subsequent release of metal ions
The formation of an adherent oxide coating on titanium implants
Micromotion at the femoral head-neck junction can lead to fretting corrosion, one of the most common causes of failure of a modular implant.
Modular components give surgeons excellent intraoperative flexibility, but are susceptible to various types of corrosion. While titanium and cobalt-chrome contain a protective surface oxide layer, continued micromotion at the modular junction may disrupt the protective layer leading to fretting corrosion, defined as micromotion at contact sites under load. This may eventually lead to a painful synovitis that necessitates a revision procedure.
Srinivasan et al. review modularity in total hip arthroplasty. Amongst other things, they discuss the modularity of the femoral head/neck junction, describing the morse taper interlocking system that provides both axial and rotational stability.
Illustration A shows an example of corrosion at the head/neck junction of a total hip arthroplasty.
Incorrect Answers:
Which of the following situations is most likely to decrease sentinel event errors?
Physician and nurse training is lengthened by 20%
Resident hours are decreased to 55 hours per week
An environment is created where all members of the healthcare team feel empowered to express their concerns and beliefs
Holding individuals responsible for errors in clinical judgement
Physicians and nurses are assigned to a smaller number of patients
Creating an environment where all members of the healthcare team feel empowered to express their beliefs increases communication, the key element in decreasing sentinel events.
Research has shown that 70% of sentinel event errors are caused by improper communication. Specific ways to improve communication include effective clinical handover between shifts and breaking down the "hierarchy" so that all members of the team can discuss their expectations and concerns. Barriers to effective communication include distractions, cultural differences, power distance relationships, time pressures, and lack of organization.
Leonard et al. describe specific clinical experiences in the application of surgical briefings, properties of high reliability perinatal care, the value of critical event training and simulation, and benefits of a standardised communication process in the care of patients transferred from hospitals to skilled nursing facilities. They recommend embedding standardized tools and behaviors to bridge differences in communications styles between clinicians.
Incorrect Answers:
Which of the following side effects is most strongly associated with the use of NSAIDs?
Hepatic dysfunction
Renal impairment
Prolonged QTc
Seizures
Hematuria
All NSAIDs have the potential to cause serious renal impairment.
NSAIDs work by inhibiting the cyclooxygenase pathway (COX), which is comprised of the COX-1 and COX-2 pathways. The COX-1 pathway is involved in prostaglandin E2– mediated gastric mucosal protection and thromboxane effects on coagulation, while the COX-2 pathway is mainly involved with the modulation of pain and fever without effect on platelet function. While selective COX-2 inhibitors have a decreased side effect profile, all NSAIDS
have the potential to cause renal impairment and their use should be limited in patients with underlying renal disease.
Horlocker et al. review multimodal pain management in the perioperative setting of a total joint arthroplasty. Specifically, they note that NSAIDs should be used cautiously in patients with underlying renal dysfunction who are to undergo a procedure with major blood loss.
Griffin et al. reviewed 1,799 patients hospitalized for acute renal failure. They found that NSAIDs increased the risk of renal failure by 58% and that NSAID use resulted in 25 excess hospital admissions per 10,000 years of use.
Illustration A shows the COX pathways and their inhibition by NSAIDs. Incorrect Answers:
It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?
Glucosamine
Cholecalciferol
Levothyroxine
Teriparatide
Bisphosphonates
Bisphosphonate therapy combined with invasive dental work increases the risk for development osteonecrosis of the jaw.
Bisphosphonates are a class of drugs that prevent bone mass loss by inhibiting osteoclast resorption. They are used in the treatment of vertebral compression fractures, non- vertebral fragility fractures, osteogenesis imperfecta, multiple myeloma, and avascular necrosis. Because bisphosphonates have been associated with osteonecrosis of the jaw, it is suggested that all invasive
dental work be completed prior to initiation of treatment.
Pazianas et al. (2011) review the safety profile of bisphosphonates. Specifically, they cite gastrointestinal discomfort, atypical femur fractures, osteonecrosis of the jaw, ocular inflammation, and musculoskeletal pain as common side effects. They state there is limited evidence surrounding
bisphosphonate's association with esophageal cancer and atrial fibrillation.
Pazianas et al. (2007) reviewed 11 publications that reported 26 cases of osteonecrosis of the jaw following initiation of bisphosphonate treatment. Age
>60 years, female sex, and previous invasive dental treatment were the most common characteristics of those who developed ONJ.
Illustration A shows the various bisphosphonates and their mechanisms of action. Illustration B shows an example of osteonecrosis of the jaw, a side effect that has been linked to bisphonphonate treatment.
Incorrect Answers:
Figures A and B show radiographs of a 24-year-old female with a soccer injury. A physical examination reveals an isolated, closed injury with no clinical features of neurovascular injury or compartment syndrome. She has been consented to be treated with intramedullary nail fixation. A pre-operative note by the anaesthesiology team makes reference to the patients fair skin and natural red-hair color. How will this information affect the post-operative management of this patient?
Longer duration of anticoagulation due to increased risk of DVT
Avoiding anticoagulation medications due to increased risk of bleeding
Require higher dosages of post-operative analgesia
Longer period of non-weight bearing on surgical limb
Avoiding opioids due to higher risk of unrecognized allergies
Female patients with natural red-hair may require higher dosages of post- operative analgesia compared to other hair types.
Melanocortin-1-receptor (MC1R) is one of the key proteins involved in hair color and skin tone. Mutations of the MC1R alleles can render this protein non- functional, which results in a phenotype of red-hair and fair skin. Mutations of the MC1R have shown to modulate the pain response and opioid efficacy in these patients. Women are more commonly affected and often require more anaesthetic and higher dosages of opioid to achieve comparable MAC level and pain-relief, respectively, as women with other hair types.
Liem et al. showed that a greater concentration of induction and maintenance agents (sevoflurane and desflurane, respectively) were required to sustain comparable MAC levels in red-haired patients as dark haired patients.
Fillingim et al. reviewed the affect of gender, sex and pain. They concluded there is a biopsychosocial element of pain that is perceived differently by men and women. In terms of postoperative and procedural pain, the outcome might be more severe in women than men.
Delaney et al. looked at the involvement of the melanocortin-1 receptor in acute pain in mice. They found that while the MC1R is better known as a gene involved in mammalian hair colour, it was shown to be involved in the pain pathway of inflammatory but not neuropathic origin. Mutations of MC1R showed increased tolerance to noxious pain stimulus in mice.
Figures A and B are AP and lateral radiographs of a left tibia. There is a low energy, distal third shaft fracture with no cortical apposition on the AP view.
Incorrect Answers:
Which of the following medications used for thromboprophylaxis following orthoapedic surgery is a direct inhibitor of factor Xa?
Dextran
Rivaroxaban (Xarelto)
Coumadin
Fondaparinux (Arixtra)
Aspirin
Rivaroxaban (Xarelto), an oral anticoagulant, is a direct inhibitor of factor Xa.
Rivaroxaban (Xarelto) is a member of a new class of oral, direct (antithrombin- independent) factor Xa inhibitors, which restrict thrombin generation both in vitro and in vivo. Inhibition of Factor Xa interrupts the intrinsic and extrinsic pathway of the blood coagulation cascade, inhibiting both thrombin formation and development of thrombi.
Eriksson et al. compare rivaroxaban to enoxaparin for the prevention of symptomatic venous embolism following total hip arthroplasty. Major venous thromboembolism occurred in 4 of 1686 patients (0.2%) in the rivaroxaban group and in 33 of 1678 patients (2.0%) in the enoxaparin group. Additionally, major bleeding events were similar between the two groups.
Illustration A shows the mechanisms of action of various agents used for thromboprophylaxis.
Incorrect Answers:
as Protein C and Protein S.
The origin of bovine derived grafts is particularly important to which of the following religious groups?
Christianity
Islam
Hinduism
Buddhism
Judaism
The origin of bovine-derived surgical implants should be discussed in further detail with patients ascribing to Hinduism.
Patients come from a variety of religious backgrounds. Depending on a patient’s religion, the origin of surgical implants may have implications for their use. In Hinduism, bovine animals are considered sacred. Use of cow by- products is considered purifying in nature. Subsequently, the origin of bovine derived implants should be discussed with patients ascribing to Hinduism.
Easterbrook et al. evaluated the utility of porcine and bovine surgical implants amongst those of Jewish, Muslim and Hindu faiths. Hindu religious leaders, who were surveyed, did not approve of the use of bovine surgical implants.
Enoch et al. evaluated the acceptability of biological products amongst various religious groups. The Hindu religious leaders were found to not have an objection to the use of biological implants derived from cows.
Illustration A shows a clinical photo of a fetal bovine derived dermal substitute. Incorrect Answers:
Immunological testing of anti-cyclic citrullinated peptide antibodies (anti- CCP) is most commonly used for the diagnosis and prognosis of which immunological condition?
Ankylosis spondylitis
Rheumatoid arthritis
Psoriatic arthritis
Systemic lupus erythematosus
Reiter's syndrome
Anti-cyclic citrullinated peptide antibodies (anti-CCP) are commonly used as a marker for the diagnosis and prognosis of rheumatoid arthritis (RA).
Immunological studies are commonly performed to investigate cases of suspected rheumatoid arthritis. Rheumatoid factor has historically been used as a primary marker for RA. However, in more recent years, the use of anti- CCP antibodies has shown to be as sensitive as, and more specific than, rheumatoid factor (RF) in early and fully established disease. In general, anti-
CCP assays equate to a sensitivity of 50-75% and a specificity of 90-95%. High levels of anti-CCP have been shown to be indicative of a more erosive disease process and may be detected before the onset of arthritis.
Gardner and Kadel reviewed the laboratory studies most commonly used in rhuematologic diseases. Standard ordering for clinically suspected RA include Rf, anti- CCP, ESR/CRP as well as other markers of autoimmune diseases such as antinuclear antibodies, anticardiolipin antibodies and lupus anticoagulant, HLA-B27, and uric acid levels.
Illustration A shows the sensitivity and specificity of anti-CCP vs. RF in a variety of autoimmune diseases.
Incorrect Answers:
Vitamin C has been shown to decrease the likelihood of which of the following complications following surgery on the foot and ankle in non-diabetic patients?
Nonunion
Complex Regional Pain Syndrome, type II
Malunion
Complex Regional Pain Syndrome, type I
Wound infection
Vitamin C has been shown to decrease the likelihood of developing complex regional pain syndrome (CRPS), type 1, when given post-operatively to patients undergoing foot and ankle and wrist surgery.
CRPS is a frequent post-operative complication, with rates varying from 10-
37%. Type I CRPS does not have an identifiable nerve lesion, while type II has an identifiable nerve lesion. Multiple studies have shown that vitamin C decreases rates of CRPS following distal radius fractures, and more recently, the same has been shown following foot and ankle surgery. While the exact mechanism of CRPS is unknown, vitamin C has been shown to reduce lipid peroxidation, scavenge hydroxyl radicals, protect the capillary endothelium, and inhibit vascular permeability. All of these characteristics of vitamin C may play a role in modulating the pain pathway.
Zollinger et al. perform a double-blind, prospective, multicenter trial where
416 patients with 427 wrist fractures were randomly allocated to treatment with placebo or treatment with 200, 500, or 1500 mg of vitamin C daily for fifty days. The prevalence of complex regional pain syndrome was 2.4% in the vitamin C group and 10.1% in the placebo group.
Besse et al. compare two groups of patients undergoing surgery on the foot and ankle to determine the effect of vitamin C on the development of CRPS, type I. CRPS type I occurred in 18 cases (9.6%) in the group not given vitamin C, and 4 cases (1.7%) in the group given vitamin C.
Illustration A shows an example of a limb affected by CRPS. Note the increased swelling, a common physical exam finding in patients afflicted with the disease.
Incorrect Answers:
A 25-year-old Spanish speaking male presents to the emergency department 6 hours after sustaining the injury seen in Figure A. He is grossly intoxicated and screaming in pain. Physical examination reveals a closed injury with overlying muscular compartments that are extremely firm to palpation. After sedating the patient, measurements of the intracompartmental pressures were all found to be
>75mmHg. His wife is Spanish speaking and expected to arrive to the hospital in 2-3 hours with a relative to help with translation. No medical translator is
available. You attempt to outline the risk and benefits of surgery to the patient, but the he repeatedly interrupts you and yells out ,"No surgery!". An English-Spanish speaking friend is with the patient and says that he has known the patient for over 2 years and will help with any decision making. What would be the next most appropriate step in the management of this patient?
Delay surgery to monitor the patient for impending compartment syndrome
Proceed with surgery with urgent fasciotomy after documenting the necessity of treatment without consent
Delay the surgery until the wife arrives and able to give informed consent with the aid of a translator
Proceed with surgery for urgent fasciotomy after obtaining informed consent from the patients friend
Respect the patients autonomy and reassess the patient in the morning when he demonstrates capacity to accurately comprehend the proposed treatment
This patient is presenting with compartment syndrome of the right tibia. In a situation of required surgery for limb threatening injury without available legal consent the surgeon should confirm and document the necessity of care with a fellow colleague.
Physicians are responsible for whether a patient is able to reasonably understand their medical condition and the nature of any proposed medical procedure, including the risks, benefits, and available alternatives. If the patient lacks this capacity, disclosure imposed by the doctrine of informed
consent are excused because irreparable harm that may result from the physician’s hesitation to provide treatment. Detailed documentation is also important. In addition, the attending physician should contact the Risk Management Dept at the hospital for support prior to surgical intervention or have a medical translator involved to ensure information is being translated properly.
Katz et al. reviewed the medical decision making process of Hispanic people. They showed that Hispanic people are more likely to permit their physician to take the predominant role in making health decisions compared to Non- Hispanic people.
Figure A shows a comminuted tibia and fibula fracture. Incorrect Answers
A Spanish speaking child sustained the injury seen in Figure A after a fall at school. He was casted in the emergency department without the assistance of an interpreter and advised to return to see an orthopaedic surgeon in 1 week. However, the family returns to the emergency department with the child 3 months later, still in the cast. What is the most likely reason the child did not attend the recommended orthopaedic follow-up visit.?
The child is a victim of neglect
The child had no symptoms of pain
He was allowed to return to school wearing the cast
Concerns of cost
Follow-up instructions were not effectively communicated
The most likely reason the child did not attend the recommended orthopaedic follow-up visit was a language barrier preventing effective communication of the intended follow-up instructions.
Communication skills and cultural competence is a key element in good orthopaedic care. Poor communication can often lead to devastating outcomes. In this example, poor communication resulted in this patient being lost to
follow-up. Language barriers must be accommodated and alternative methods of communication must be utilized.
Levinson et al. examined how patients present their medical issues in clinical encounters and how physicians respond to these clues in routine primary care and surgical settings. They showed that good communication relies mostly on the physicians ability to identify patient clues within the clinical encounter.
Poor communication between the physician tended to delay clinical visits, poor follow-up and unsatisfactory outcomes.
Figure A is an AP radiograph of the elbow in a skeletally immature patient. Figure B is a lateral radiograph of the elbow with a posterior fat pad sign, suggestive of an occult fracture.
Incorrect Answers:
A 25-year-old female presents to the emergency room within increasing left shoulder pain after walking into a door 5 months ago. She previously sustained a femoral fracture 2 years ago after tripping on a rug. Relevant skeletal survey radiographs and tissue biopsy results are shown in Figures A through D. Laboratory investigations show normal glomerular filtration rate and creatinine clearance. Dual energy x-ray absorptiometry (DEXA) scan shows T-score of -1.4 and
-1.2 at the hip and lumbar spine, respectively. Which of the following laboratory values in Figure E most likely reflects this patient's condition?
A
B
C
D
E
This patient has primary hyperparathyroidism. Laboratory investigations are likely to show elevated serum intact parathyroid hormone (PTH), alkaline phosphatase (ALP) and ionized serum calcium, and low serum phosphate.
Primary hyperparathyroidism is most commonly caused by a single adenoma (80-90%). Besides the signs and symptoms of hypercalcemia, patients present
with calcification of menisci and articular cartilage, erosions in hand bones, "salt and pepper skull", and brown tumors (osteoclastomas), which appear as lytic regions expanding the cortex and causing pathological fractures, so named because of hemosiderin deposition.
Singhal et al. reviewed primary hyperparathyroidism. They advocate routine serum calcium levels for patients with pathologic fractures. If this is elevated, total and ionized calcium and intact PTH levels should be obtained. They feel that surgery for orthopaedic stabilization and parathyroidectomy should be performed simultaneously for better outcome.
Mankin et al. reviewed metabolic bone disease. They suggest that patients with mild disease with normal calcium levels do not require treatment. For patients with high calcium levels, treatment should include maintenance of fluid balance, localization and removal of the adenoma, bony stabilization, and medications (calcitonin, estrogen, bisphosphonates, and calcimimetics such as cinacalcet).
Figure A is an AP radiograph showing a lytic expansile lesion with pathological fracture in metadiaphyseal region of left humerus with similar lesion in the
fifth posterior rib. Figure B is an AP radiograph showing a lytic expansile lesion in the third metacarpal of the right hand and the fifth metacarpal of the left hand. Figure C is a low power micrograph of a brown tumor demonstrating a central zone of bone resorption, and filling with fibroblastic tissue, with a peripheral rim of osteoid production. Figure D is a high power micrograph of a brown tumor. In areas of bone resorption, there are numerous osteoclast-like giant cells amidst a fibrous stroma. This is unlike a true giant cell tumor, which lacks a fibrogenic stroma.
Incorrect Answers:
and impaired 1,25-dihydroxyvitamin D production by the diseased kidneys. This patient has normal renal function. Answer 3: Elevated PTH, ALP, serum calcium and phosphate occur in tertiary hyperparathyroidism. This again occurs in chronic renal disease after prolonged chronic secondary hyperparathyroidism or after renal transplantation, where the parathyroid glands become autonomous and PTH levels do not normalize. This patient has normal renal function.
elevated.
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Question 81:

Options:

ACL reconstruction and subsequent proximal tibial osteotomy
ACL reconstruction alone
Distal femoral osteotomy with simultaneous ACL reconstruction
Proximal tibial osteotomy with subsequent ACL reconstruction

Correct Answer: Proximal tibial osteotomy with subsequent ACL reconstruction

Explanation:

Question 82:

Options:

His clinical outcome will correlate closely with his initial reduction.
His outcome will correlate with his radiographic score on the Ankle Osteoarthritis Score.
He will likely require a late ankle arthrodesis.
He will demonstrate marked limitations with regard to recreational activities.
He will perceive improvements for a period of over 2 years.

Correct Answer: He will perceive improvements for a period of over 2 years.

Explanation:

Marsh and associates retrospectively reviewed 56 tibial plafond fractures and found that the patients perceived improvement in their function and pain for an average of

Question 83:

Options:

Staphylococcus aureus
Staphylococcus epidermidis
Propionibacterium acnes
Escherichia coli
Pseudomonas aeruginosa

Correct Answer: Propionibacterium acnes

Explanation:

Question 84:

Options:

closed reduction.
symptomatic sling support and range-of-motion exercises.
arthroscopic thermal capsulorrhaphy.
an open anterior-inferior capsular shift.
a Laterjet procedure.

Correct Answer: symptomatic sling support and range-of-motion exercises.

Explanation:

Question 85:

The patient returns 1 year later to report curling of her toes and numbness on the plantar surface of her foot. What is the most likely cause of this condition?

Options:

CRPS
Plantar fasciitis
Plantar fibromatosis
Subclinical compartment syndrome

Correct Answer: Subclinical compartment syndrome

Explanation:

DISCUSSION
Radiographs reveal a Lisfranc fracture dislocation with fractures of the first and second metatarsals. Tenting of skin that is over a bony prominence is an orthopaedic emergency. The fracture dislocation should be reduced without delay. There is no evidence of compartment syndrome of the foot, but this may develop and monitoring is necessary. Toe deformity may develop on a delayed basis because of the subclinical presentation. Nerve irritation is not uncommon with dorsal midfoot surgical incisions. A positive Tinel test result over the midfoot in the distribution of the superficial common peroneal nerve is consistent with a stretch injury to this nerve. CRPS is usually associated with multiple nerve distributions and autonomic nerve findings such as cold hypersensitivity and hyperhidrosis.
RECOMMENDED READINGS
Benirschke SK, Meinberg EG, Anderson SA, Jones CB, Cole PA. Fractures and dislocations of the midfoot: Lisfranc and Chopart injuries. Instr Course Lect. 2013;62:79-91. PubMed PMID: 23395016.
View Abstract at PubMed
Schepers T, Oprel PP, Van Lieshout EM. Influence of approach and implant on reduction accuracy and stability in lisfranc fracture-dislocation at the tarsometatarsal joint. Foot Ankle Int. 2013 May;34(5):705-10. doi: 10.1177/1071100712468581. Epub 2013 Jan 14. PubMed
PMID: 23637239.
View Abstract at PubMed

Question 86:

- A patient sustains a closed dorsal dislocation of the proximal interphalangeal joint of the middle finger without an associated fracture. Closed treatment results in a cocentric stable reduction. The finger is not immobilized. Which of the following conditions may appear 1 year later?

Options:

Triggering
Lateral instability
Swan-neck deformity
Boutonniere deformity
Loss of distal interphalangeal joint flexion

Correct Answer: Triggering

Explanation:

Swan neck deformity describes a posture of the finger in which the PIP joint is hyperextended and the DIP joint is flexed. Initially this is a dynamic imbalance that occurs when a patient attempts maximal digital extension. This dynamic finger imbalance can progress to a static deformity. There are many etiologies for SND and include injuries resulting in volar plate laxity (e.g. dorsal dislocation of the PIP.), spastic conditions such as stroke & CP, RA, fractures of the middle and proximal phx healed in extension.
Question 199 -
Examination of a 3-year-old boy who slammed his finger in a door 3 months ago reveals 0 to 40 degrees of proximal interphalangeal joint motion. Radiographs are shown in Figures 47a and 47b. Management should consist of
Volar osteotomy
Observation only
Flexor tenolysis
Volar plate arthoplasty
A hinged distraction external fixator
Subcondylar fractures of the proximal and middle phalynx occur at the neck of the phalynx, usually as a result of a crush injury, and almost exclusively in the pediatric age group. The distal fragment rotates dorsally and the degree of displacement may be misjudged if a true lateral is not obtained. If malunion occurs there is block to flexion. Subcondylar fossa reconstruction by removal of bone through a palmar approach removes this boney block.

Question 87:

What is the most frequent late complication of cementless fixation in total knee arthroplasty?

Options:

Infection
Subluxation of the patella
Loss of motion
Femoral loosening
Osteolysis

Correct Answer: Osteolysis

Explanation:

Question 88:

Based on the Young and Burgess classification of pelvic ring injuries, an anterior-posterior compression type II injury does not result in disruption of which of the following?

Options:

pubic symphysis
anterior sacroiliac ligaments
posterior sacroiliac ligaments
sacrospinous ligament
sacrotuberous ligament

Correct Answer: pubic symphysis

Explanation:

Question 89:

Options:

A locked plate construct (locked screws) or hybrid construct (locked and non-locked screws) is necessary.
Periosteal stripping is performed through two incisions proximal and distal to the fracture.
Bridge plating is performed following direct reduction of the fracture.
AO Type A diaphyseal fractures are best treated with this technique.
Bridge plating with a long working length creates a flexible, axially stable construct.

Correct Answer: A locked plate construct (locked screws) or hybrid construct (locked and non-locked screws) is necessary.

Explanation:

Question 90:

Options:

Removal of the implant alone
Amputation of the hallux
Revision of the implant with a Silastic joint replacement
Arthrodesis of the hallux metatarsophalangeal joint with interposition bone graft
Rocker bottom steel shank shoe with orthosis

Correct Answer: Arthrodesis of the hallux metatarsophalangeal joint with interposition bone graft

Explanation:

Question 91:

A 53-year-old man has a 4- x 5-cm high-grade soft-tissue sarcoma in the midthigh. As part of the staging evaluation, regional nodes should be assessed by

Options:

CT of the pelvis and groin.
sentinal node biopsy.
clinical examination.
fine needle aspiration.
prophylactic inguinal node dissection.

Correct Answer: clinical examination.

Explanation:

Question 92:

-This boy’s parents are eager to get him back on the field as soon as possible. What is the most appropriate treatment option?

Options:

Screw fixation of the epiphysis
Arthroscopic debridement
A shut-down period until the boy is asymptomatic, and gradual return to pitching via a throwing program
An intra-articular cortisone injection

Correct Answer: A shut-down period until the boy is asymptomatic, and gradual return to pitching via a throwing program

Explanation:

DISCUSSION FOR QUESTIONS 60 AND 61
Although a recent increase in the number of pitches may have contributed to this patient’s development of little leaguer’s shoulder, the most significant overall factor is age. Little leaguer’s shoulder is caused by rotational stress placed on the proximal humeral epiphysis during overhead throwing. The growth plate is weakest to torsion stress, and is most susceptible to injury during periods of rapid growth commonly seen during puberty. Most chronic shoulder injuries occur in throwing athletes between 13 and 16 years of age. Genetic factors and gender have not been studied in association with little leaguer’s shoulder. An initial 3-month period of rest and activity modification will typically result in resolution of symptoms.Nonsteroidal anti-inflammatory drugs may be used as needed. After the rest period, a gradual return to baseline pitching is implemented until the patient is back to baseline. This protocol has a long-term success rate exceeding 90%.

Question 93:

What structure (arrow) is shown in Figure 24?

Options:

Ilioinguinal nerve
Sympathetic chain
Ureter
Iliac vein
L5 nerve

Correct Answer: Sympathetic chain

Explanation:

DISCUSSION: The structure illustrated is the sympathetic chain viewed from an anterolateral view of the lower lumbar spine. It descends along the anterolateral aspect of the spine into the pelvis closely adherent to the vertebral column. The spinal nerves, including L5, can be seen exiting from the foramen. The ureters descend from the kidneys and cross anterior to the iliac vessels to the bladder.
REFERENCES: Onibokun A, Khoo LT, Holly L: Anterior retroperitoneal approach to the lumbar spine, in Kim DH, Henn JS, Vaccaro AR, et al (eds): Surgical Anatomy and Techniques to the Spine. Philadelphia, PA, Saunders Elsevier, 2006, pp 101-105.
Netter GH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy Corporation, 1989.

Question 94:

Options:

HIV
Staph Aureus
Hepatitis A
Hepatitis B
Hepatitis C

Correct Answer: HIV

Explanation:

Question 95:

Options:

remain essentially unchanged in size.
result in neurologic deterioration.
gradually resorb and widen the spinal canal.
potentially migrate within the spinal canal.
increase the risk of further injury to the adjacent dural sac.

Correct Answer: gradually resorb and widen the spinal canal.

Explanation:

Question 96:

Which wear mechanism is most likely responsible for the wear damage on the modular tibial insert retrieval shown in Figure 82?

Options:

Adhesive
Abrasive
Fatigue
Creep

Correct Answer: Fatigue

Explanation:

Question 97:

Options:

Physical therapy and a home exercise program
Corticosteroid injection
Arthroscopic debridement
Microfracture
Osteochondral autograft transplantation (OAT)

Correct Answer: Osteochondral autograft transplantation (OAT)

Explanation:

Question 98:

Options:

Eccentric contraction
Closed chain exercise
Open chain exercise
Proprioceptive neuromuscular facilitation
Isometric contraction

Correct Answer: Open chain exercise

Explanation:

Question 99:

The spinal cord terminates as the conus medullaris at what vertebral level in adults? Review Topic 1 T12

Options:

Correct Answer: L2

Explanation:

The spinal cord anatomy changes at the thoracolumbar junction. The spinal cord terminates as the conus medullaris at the lower portion of L1 in women and the pedicle of L1 in men.

Question 100:

A 2-year-old girl has the fracture shown in Figures 5a and 5b. This fracture is most commonly associated with which of the following entities? Review Topic

Options:

Neurofibromatosis
Child abuse
Osteogenesis imperfecta type II
Osteopetrosis
Achondroplasia

Correct Answer: Neurofibromatosis

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Spine Part 255

Orthopedic Board Prep MCQs: Adult Reconstruction & Foot | Part 174

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 174

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index