Orthopedic Board Review MCQs: Knee & Shoulder | Pt 189

About This Board Review Set

This is Part 189 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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Topics Covered in Part 189

This module focuses heavily on: Knee, Nerve, Revision, Shoulder.

Sample Questions from This Set

Sample Question 1: At the time of acetabular revision, retention of well-fixed femoral components inserted with first-generation cementing technique is most commonly associated with which of the following factors?...

Sample Question 2: A 48-year-old man who is scheduled to undergo total knee replacement has an X-linked clotting disorder that leads to abnormal bleeding and recurrent, spontaneous hemarthrosis. Before undergoing surgery, he should have replacement therapy of...

Sample Question 3: Figure 72 is the MRI scan of a 61-year-old man who had left shoulder pain with a massive rotator cuff tear. Active forward elevation was 120 degrees. Arthroscopic examination revealed that the rotator cuff tear was irreparable. The articula...

Sample Question 4: A 25-year-old athletic woman has a 16-week history of left lower-extremity radiating pain in an S1 distribution. MR images obtained by her family physician reveal a large L5-S1 paracentral disk herniation impinging on the left S1 nerve root...

Sample Question 5: Figures 1 and 2 depict the postoperative radiographs obtained from a 22-year-old man who was involved in a motor vehicle accident. The most likely limitation in motion arising from this treatment is...

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

Comprehensive 100-Question Exam

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Question 1

At the time of acetabular revision, retention of well-fixed femoral components inserted with first-generation cementing technique is most commonly associated with which of the following factors?

Explanation

Peters et al reviewed the results of 37 hips in which a well fixed femoral component that had originally been implanted with first generation cementing techniques was left in place at the time of acetabular revision. There was no significant increase in loosening, infection, dislocation or polyethylene wear. The predicted rate of survival of the femoral component after revision of only the acetabular component was 88% at 48 months and 78°% after 88 months. This author recommends retaining a well fixed femoral component that has been implanted with 1st generation cementing techniques during acetabular revision.

Question 2

A 48-year-old man who is scheduled to undergo total knee replacement has an X-linked clotting disorder that leads to abnormal bleeding and recurrent, spontaneous hemarthrosis. Before undergoing surgery, he should have replacement therapy of

Explanation

Hemophilia A is an X-linked recessive deficiency of factor VIII that can lead to significant bleeding problems including recurrent spontaneous hemarthroses that can lead to synovitis and joint destruction. von Willebrand disease is a lack of von Willebrand factor that leads to decreased platelet aggregation; more commonly patients have mucosal bleeding and not hemarthroses. Vitamin K deficiency is not hereditary; it is typically attributable to inadequate dietary intake, malabsorption, and loss of storage sites from hepatocellular disease. Protein C and S deficiencies are autosomal-dominant diseases that lead to thrombosis, not bleeding, as protein C and S shut off thrombin formation.

Question 3

Figure 72 is the MRI scan of a 61-year-old man who had left shoulder pain with a massive rotator cuff tear. Active forward elevation was 120 degrees. Arthroscopic examination revealed that the rotator cuff tear was irreparable. The articular surfaces of the glenohumeral joint have a normal appearance without significant degenerative changes. What is the most appropriate treatment option? Review Topic

Explanation

The MRI scan shows medial subluxation of the biceps tendon. Biceps tenotomy has been an effective treatment option for patients with large to massive rotator cuff tears when the tear is irreparable and pain is the main symptom. The MRI scan does not show a loose body. Patients with severe external rotation deficit and a deficient teres minor may experience a better functional result with latissimus dorsi transfer. Reverse total shoulder arthroplasty is an option in patients with cuff tear arthropathy and pseudoparalysis.

Question 4

A 25-year-old athletic woman has a 16-week history of left lower-extremity radiating pain in an S1 distribution. MR images obtained by her family physician reveal a large L5-S1 paracentral disk herniation impinging on the left S1 nerve root. You suggest a left-sided L5-S1 microdiskectomy and tell her that when comparing tubular diskectomy and open procedures

Explanation

DISCUSSION
Several comparative studies have reported no difference in functional outcomes between tubular diskectomy and microsurgical lumbar diskectomy. A recent systematic review by Kamper and associates in which conventional microdiskectomy and minimally invasive approaches were compared revealed that there was no difference between the procedures in terms of clinical outcomes, complication risk, or rate of revision surgery.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis. Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183.View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 5

Figures 1 and 2 depict the postoperative radiographs obtained from a 22-year-old man who was involved in a motor vehicle accident. The most likely limitation in motion arising from this treatment is

Explanation

EXPLANATION:
This patient sustained fractures of his radius and ulna; both were treated with plate and screw fixation. The plate used on the radius was straight, resulting in loss of the radial bow, which is critical for enabling the radius to curve around the ulna during pronation. This patient is unable to pronate beyond 20°. Schemitsch and Richards correlated a good functional outcome, defined as more than 80% of normal rotation of the forearm, with restoration of the normal amount and location of the radial bow. Additionally, they related the restoration of grip strength with appropriate restoration of the radial bow. Matthews and associates reported little significant loss of rotation with 10° of angulation; however, 20° of angulation resulted in a statistically and clinically significant loss of forearm rotation.

Question 6

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

Explanation

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

Question 7

Which of the following cardiac conditions is considered an absolute contraindication to vigorous exercise?

Explanation

DISCUSSION: Hypertrophic cardiomyopathy (HCM) accounts for up to 50% of cases of
sudden death in young athletes. HCM phenotype becomes evident by age 13 to 14 years. Those at higher risk include individuals with cardiac symptoms, a family history of inherited cardiac disease, and those with a family history of premature sudden death. Echocardiography is useful for detecting structural heart disease, including the cardiomyopathies and valvular abnormalities. Trained adolescent athletes demonstrated greater absolute left ventricular wall thickness (LVWT) compared to controls. HCM should be considered in any trained adolescent male athlete with a LVWT of more than 12 mm (female of more than 11 mm) and a nondilated ventricle. Adolescent and adult athletes differ with respect to the range of LVWT measurements, as a manifestation of left ventricular hypertrophy (LVH). Differentiating LVH (“athlete’s heart”) from HCM involves looking at additional echocardiographic features. Sharma and associates reported that adolescents with HCM had a small or normal-sized left ventricle (less than 48 mm) chamber size, while those with LVH had a chamber size at the upper limits of normal (52 mm to 60 mm).
REFERENCES: Sharma S, Maron BJ, Whyte G, et al: Physiologic limits of left ventricular hypertrophy in elite junior athletes: Relevance to differential diagnosis of athlete’s heart and hypertrophic cardiomyopathy. J Am College Cardiol 2002;40:1431-1436.
Maron BJ, Spirito P, Wesley Y, et al: Development and progression of left ventricular hypertrophy in children with hypertrophic cardiomyopathy. N Engl J Med 1986;315:610-614.
Pelliccia A, Culasso F, Di Paolo FM, et al: Physiologic left ventricular cavity dilatation in elite athletes. Ann Intern Med 1999;130:23-31.

Question 8

In addition to pain, which of the following factors are considered most predictive of the risk of pathologic fracture?

Explanation

DISCUSSION: While guidelines for predicting fracture risk are at best imprecise, the scoring system by Mirels (pain, anatomic location, and pattern of bony destruction) has been shown to be most predictive of fracture risk. Functional pain, peritrochanteric location, and lytic bone destruction are the greatest risk factors for pathologic fracture. The factors of patient weight, age, soft-tissue mass, and location within bone are all of lesser importance.
REFERENCES: Frassica FJ, Frassica DA, McCarthy EF, Riley LH III: Metastatic bone disease: Evaluation, clinicopathologic features, biopsy, fracture risk, nonsurgical treatment, and supportive management. Instr Course Lect 2000;49:453-459.
Mirels H: Metastatic disease in long bones: A proposed scoring system for diagnosing impending pathologic fractures. Clin Orthop 1989;249:256-264.

Question 9

Which of the following occurs frequently after nonsurgical management of displaced intra-articular fractures of the calcaneus?

Explanation

Peroneal tendinitis and stenosis are typically seen following nonsurgical management and results from lateral subfibular impingement, whereby the displaced, expanded lateral wall subluxates the peroneal tendons against the distal tip of the fibula or might even dislocate the tendons. Nonsurgical management of displaced calcaneal fractures offers little chance for return to normal function because of the development of a calcaneal malunion. The articular surface is not reduced, the heel remains shortened and widened, the talus is dorsiflexed in the ankle mortise, and the displaced lateral wall causes impingement and binding of the peroneal tendons.

Question 10

In surgically treating hand and finger infections in patients with diabetes mellitus, what factor is associated with higher amputation rates?

Explanation

DISCUSSION: Patients with diabetes mellitus are prone to infection, and surgical treatment of their infections frequently requires multiple procedures. The triad of poor wound healing, chronic neuropathy, and vascular disease contributes to the increased infection rate. Studies have demonstrated increased amputation rates in patients with diabetes mellitus who have renal failure or deep polymicrobial or gram-negative infections.
REFERENCES: Gonzalez MH, Bochar S, Novotny J, et al: Upper extremity infections in patients with diabetes mellitus. J Hand Surg Am 1999;24:682-686.
Trumble TE (ed): Hand Surgery Update 3: Hand, Elbow, & Shoulder. Rosemont, IL, American Society for Surgery of the Hand, 2003, pp 433-457.
Kour AK, Looi KP, Phone MH, et al: Hand infections in patients with diabetes. Clin Orthop Relat Res 1996;331:238-244.

Question 11

Arthritic change in cartilage is characterized by which of the following findings?

Explanation

Experimental models of late-stage arthritis in animals demonstrated lower compressive modulus, higher permeability, and higher water content. There is proteoglycan loss within the matrix. A significant and progressive decrease in the tensile and shear modulus has been observed.

Question 12

A 78-year-old man has a history of worsening bilateral calf pain with activity. MRI scans are shown in Figures 31a through 31d. His symptoms are not improved with forward flexion of the lumbar spine. His lower extremity pain is relieved when he sits or ceases activity. Which of the following tests would be most helpful in establishing a diagnosis? Review Topic

Explanation

The differential diagnosis of degenerative lumbar stenosis is extensive. Vascular and neurogenic claudication frequently coexist in the older population. Therefore, it is important to determine the specific etiology of a patient's lower extremity claudication prior to any surgical intervention. Vascular claudication is relieved with cessation of activity, whereas neurogenic claudication requires that the patient sit down or flex the lumbar spine forward to increase the canal diameter. Because this patient does not experience improvement in his symptoms with sitting or forward flexion, it is likely that he is experiencing vascular claudication. The ankle-brachial index (ABI) is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared with the arm, lower blood pressure in the leg is a sign of peripheral vascular disease. The ABI is calculated by dividing the systolic blood pressure in the arteries at the ankle and foot by the higher of the two systolic blood pressures in the arms. An ABI value between 0.40 to 0.80 is moderately decreased and such patients often experience symptoms such as intermittent claudication. Selective nerve root blocks prove to be more useful in identifying specific level(s) of involvement in patients experiencing radicular pain and paresthesias. Their utility is less helpful in lower extremity claudication. Electrophysiologic studies are rarely useful, except in identifying the presence and source of a peripheral neuropathy. About 80% of patients with symptomatic lumbar stenosis will demonstrate electromyographic changes. Osteoarthritis of the hip may be associated with buttock, groin, hip, and thigh pain.
Decreased range of motion and hip joint pain, especially in internal rotation and abduction, are common findings in patients with degenerative arthritis of the hip. While post-myelography CT has been found superior to MRI as a single study for the preoperative planning of decompression for lumbar spinal stenosis, it will not assist in differentiating vascular from neurogenic claudication.

Question 13

Integrins function in which of the following ways?

Explanation

Integrins are groups of molecules essential for osteoclast attachment to the bone surface.
Integrins are a large family of heteromeric cell surface receptors composed of non-covalently bound alpha and beta subunits which interact with extracellular matrix molecules, serum constituents and various adhesion molecules. Specifically, aVß3 is a type of integrin found on osteoclasts that attaches to bone by coupling with vitronectin.
Bikle reviews the cause of bone loss during periods of unloading. They state the during periods of rest, integrin expression is decreased, leading to disuse osteoporosis. They argue that drugs that selectively regulate the integrin signaling pathway may
reverse bone loss during periods of disuse.
Illustration A shows an example of an osteoclast attaching to bone via the integrin aVß3.
Incorrect
1:
This
is
the
function
of osteocytes.
2:
This
is
the
function
of osteoblasts.
3:
This
is
the
function
of
osteoprogenitor cells.

Question 14

A child with an idiopathic clubfoot is successfully treated by the Ponseti method. The risk of recurrence of the deformity is most dependent on which of the following factors? Review Topic

Explanation

The recurrence rate of clubfoot deformity after successful correction by the Ponseti method has been shown to inversely correlate with reported brace compliance. Maternal age, walking age, and body mass index have not been correlated to recurrence. A positive family history increases the risk of a child being born with a clubfoot but does not influence the recurrence rate.

Question 15

A patient with Paget disease who is intolerant of bisphosphonates is given calcitonin. What is the mechanism of action of calcitonin?

Explanation

Calcitonin is a hormone that reduces serum calcium concentration by directly interfering with osteoclast maturation via receptors. Calcitonin inhibits phosphate reabsorption and decreases calcium reabsorption in the kidneys. By attenuating cartilage breakdown and stimulating cartilage formation via inhibitory pathways of matrix metalloproteinases, calcitonin also has a chondro-protective effect on articular cartilage. Calcitonin has no major effects on intestinal absorption of calcium, but may aid in small-bowel secretion of sodium, potassium, chloride, and water. Calcitonin also has no receptor effect on osteoblasts.

Question 16

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

Explanation

DISCUSSION: A significant bunionette deformity that fails to respond to conservative management is best addressed surgically, in this case with the bunion deformity. The radiograph reveals a prominent lateral condyle at the fifth metatarsal head without a significant increase in the intermetatarsal angle. Simple exostectomy is preferred with less risk of complications. Complete excision would risk transfer lesions to the medial metatarsals.
REFERENCES: Mann RA, Coughlin MJ: Adult hallux valgus, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 415-435.
Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 163-173.

Question 17

A 55-year-old man falls from a ladder and dislocates his nondominant shoulder. He undergoes an uncomplicated closed reduction under sedation in the emergency department. Postreduction radiographs reveal a small Hill-Sachs lesion and no other bony abnormalities. Six weeks after the dislocation, the patient has persistent pain at rest and forward elevation and external rotation weakness, but the remaining motor function in the extremity and sensation are intact. What is the best next step?

Explanation

For a patient >40 years of age who has persistent pain and weakness isolated to the rotator cuff following an acute anterior shoulder dislocation, an MRI is indicated to evaluate rotator cuff integrity. EMG is not indicated in this case because this patient has no evidence of distal motor functional abnormality and their sensation is intact, thereby making a brachial plexus injury unlikely. Corticosteroid injections and physical therapy
modalities do not adequately address the concern over his potential for having sustained a rotator cuff tear.

Question 18

A B C D Figures 75a through 75d show the radiographs of an 85-year-old woman who fell from a step and sustained a right proximal femur fracture. Six months after surgery she has knee pain. What is the most likely cause of her pain?

Explanation

DISCUSSION
Three cases of anterior distal femoral cortex penetration during intramedullary nailing for subtrochanteric fractures were documented by Ostrum and Levy in a 2005 study. Case 1 involved a Zimmer (Warsaw, Indiana) M/DN antegrade femoral nail, Case 2 involved a Stryker (Mahwah, New Jersey) long-stem Gamma nail, and Case 3 a DePuy Synthes (West Chester, Pennsylvania) titanium femoral nail with spiral blade locking. The anterior Zimmer nail penetration resulted in a displaced supracondylar fracture, which subsequently required revision. The Gamma nail as well as the DePuy Synthes nail were left impaled through the distal femoral cortex, and the subtrochanteric fractures went on to union. The anteroposterior radius of curvature for the Zimmer, long Gamma, and DePuy Synthes nails is 257 cm, 300 cm, and 150 cm, respectively. It is estimated that the radius of curvature of the femoral diaphyseal canal is 114 to 120 cm. It appears that the difference in femoral anteroposterior bow between the bone and the implant is a contributing factor to distal femoral anterior cortex penetration in intramedullary nailing of subtrochanteric fractures. There is no evidence of osteoarthrosis on the radiographs. Although nonunion is possible, based on the radiographic findings it is more likely that this patient's pain is attributable to the curvature of the nail. The lateral image of the hip reveals an appropriate starting point for the device.
RECOMMENDED READINGS
Ostrum RF, Levy MS. Penetration of the distal femoral anterior cortex during intramedullary nailing for subtrochanteric fractures: a report of three cases. J Orthop Trauma. 2005 Oct;19(9):656-60. PubMed PMID: 16247312.View Abstract at PubMed
Egol KA, Chang EY, Cvitkovic J, Kummer FJ, Koval KJ. Mismatch of current intramedullary nails with the anterior bow of the femur. J Orthop Trauma. 2004 Aug;18(7):410-5. PubMed PMID: 15289685. View Abstract at PubMed
RESPONSES FOR QUESTIONS 76 THROUGH 78
- Nonsurgical treatment with closed reduction and immobilization
- Early mobilization with physical therapy initiated within 2 weeks
- Open reduction and internal fixation (ORIF) with locked implants
- Use of supplemental bone graft or substitutes
- Arthroplasty
- Workup for osteoporosis and counseling
Which intervention listed is most appropriate to address each scenario described?

76A B

Question 19

A 10-month-old infant has no flexion at the elbows, mild flexion contractures at the wrist, a rigid clubfoot deformity on the left foot, and a rigid rocker bottom deformity on the right foot. Examination of the patient's hips reveals limited

Explanation

The patient has arthrogryposis. Szoke and associates performed open reduction through a medial approach on 40 hip dislocations in 26 patients with this condition and reported good results in 80% and fair results in 12%. Due to the stiffness associated with this disorder, closed reduction with or without skin or skeletal traction is not feasible. Open reduction through an anterior approach is reserved for older children.

Question 20

A 17-year-old high school football linebacker sustains an injury while making a tackle. His initial symptoms are right shoulder pain, bilateral biceps weakness, and right arm numbness. The symptoms only last a few minutes, and he continues to play in the game. He tells his parents after the game, and they bring him to your office for evaluation the next day. He no longer has any symptoms, and his examination findings and cervical spine radiographs are normal. What is the best next step?

Explanation

The football player had bilateral weakness indicating that the injury was more significant than a stinger. Stingers present with unilateral symptoms, and if they resolve, an athlete can return to sports. However, bilateral symptoms indicate cervical spine pathology, such as spinal stenosis, and warrant an MRI scan of the cervical spine. Despite the patient being able to continue playing in the game and having symptom resolution, a cervical MRI scan should be performed prior to return to sports.

Question 21

Figures 37a & 37b show radiographs of a right handed, 78 year old man who had painful G-H arthritis, moderate limitation of motion, and good strength prior to replacement of the humeral head 2 years ago. At the time of treatment, the rotator cuff was intact. He now has limited motion, weakness, and persistent pain in the shoulder. What is the most likely diagnosis?

Explanation

[Radiograph: Shows a well fixed prosthesis, possible superiorly migrated. There is no “joint space” between the prosthesis and the glenoid.]
The referenced text states that the most frequent complications in shoulder hemiarthroplasty are due to rotator cuff and tuberosity problems or postoperative instability. Return of motion is expected to be two-thirds to three fourths of pre-operative. 80-90% of patients undergoing hemiarthroplasty experience pain relief. Of the 10-20% who fail to get relief, conversion to total shoulder arthroplasty should be considered. The referenced article discusses the excellent results of TSA and not the reasons for hemi failure. The point strongly emphasized in the article was that for those patients requiring conversion to TSA, strongly suspect infection.

Question 22

A 35-year-old woman with type 1 diabetes mellitus has been treated for the past 2 years at a wound care center for persistent bilateral fifth metatarsal head ulcers. Management has consisted of shoe wear modifications, treatment with multiple enzymatic ointments, and a fifth metatarsal head resection on the left side. Physical examination reveals intact pulses, minimal ankle dorsiflexion, neutral hindfoot, and a persistent ulcer under the fifth metatarsal heads. What treatment will best help heal the ulcers?

Explanation

DISCUSSION: The patient likely has a significant Achilles contracture that causes her to always bear more weight on her forefoot. A gastrocnemius recession takes the ankle out of plantar flexion and she will be able to return to a normal gait and reduce the pressures on her forefoot. A forefoot amputation is a salvage option. The other choices are appropriate; however, the patient has had this problem for 2 years and she has already had multiple attempts at shoe wear modification.
REFERENCES: Laughlin RT, Calhoun JH, Mader JT: The diabetic foot. J Am Acad Orthop Surg 1995;3:218-225.
Aronow MS, Diaz-Doran V, Sullivan RJ, et al: The effect of triceps surae contracture force on plantar foot pressure distribution. Foot Ankle Int 2006;27:43-52.

Question 23

A 39-year-old female presents with the following motor vehicle crash with the injury seen in Figure A (immobilized in a pelvic binder). The iatrogenic neurologic injury most commonly caused by placement of the anterior construct for this injury, as shown in Figure B, would cause which of the following?

Explanation

This patient was treated with posterior stabilization, and an anterior subcutaneous internal fixator (ASIF). The most common neurologic injury seen following placement of the ASIF construct is irritation of the lateral femoral cutaneous nerve (LFCN), causing numbness and/or pain of the lateral thigh.
Unstable pelvic fractures can be treated in a multitude of ways. The ASIF construct is typically created by placing long pelvic screws or polyaxial pedicle screws in the supraacetabular region, similar to the supraacetabular pins for an anterior external fixator. Then a curved bar is placed subcutaneously and connected to the supraacetabular screws. They are typically removed after 3-4 months when fracture healing is complete.
Vaidya et al. present a retrospective review of the use of ASIF as definitive treatment of unstable pelvic fractures. All patients in the study tolerated the construct well. LFCN irritation was seen in 30% of patients, and resolved in all but one patient.
Müller et al. present a retrospective review of the use of posterior stabilization and ASIF. They report an acceptably low complication rate, and good to excellent outcomes in 64.5% of patients.
Figure A is a radiograph demonstrating a right APC3 and left APC2 pelvic injury, imaged in a pelvic binder. Figure B is a postoperative radiograph following posterior stabilization and ASIF.
Incorrect answers:

Question 24

A patient who underwent a L4-L5 hemilaminotomy and partial diskectomy for radiculopathy 8 weeks ago now reports increasing low back pain without neurologic symptoms. A sagittal T2-weighted MRI scan is shown in Figure 13a, and a contrast enhanced T1-weighted MRI scan is shown in Figure 13b. What is the most appropriate management for the patient’s symptoms? Review Topic

Explanation

The MRI scans show Modic changes in the L4-L5 vertebral bodies due to spondylosis. There is no increased fluid signal or enhancement in the L4-L5 disk to suggest infection or any other pathologic process. Therefore, the patient’s pain should be treated with a course of physical therapy and rehabilitation. There is no infection; therefore, IV antibiotics and debridement are not indicated. Similarly, a
pseudomeningocele is not present. A revision diskectomy is useful for recurrent radiculopathy but would not be helpful for degenerative low back pain.
(SBQ12SP.29) A 17-year-old female is undergoing posterior instrumented fusion from T5-T12 for adolescent idiopathic scoliosis. At the time of the correction maneuver, the neurophysiologist notifies you of a 60% decrease in somatosensory evoked potential (SSEP) amplitude throughout bilateral lower extremities. Which of the following is an acceptable approach to manage this finding? Review Topic
Immediate wake-up test with examination for clonus
Drop the mean arterial pressure (MAP) to ~60mmHg
Discontinue instrumentation and optimize MAP to 85mmHg or greater
Immediate infusion of intravenous corticosteroids
Modification of the anesthesia plan to include inhalational agents only followed by repeated SSEP testing
The patient has a significant drop in SSEP amplitudes at the completion of the corrective maneuver. The most appropriate response is to raise the MAP to 85 mmHg or greater, discontinue the instrumentation, re-evaluate the SSEPs, and if there is no improvement, to consider reversing the reduction of the deformity.
Intra-operative neurophysiologic monitoring is an effective method to monitor insults to the spinal cord and its exiting roots during spinal instrumentation. The common measurements include SSEPs, which monitor sensory potentials transmitted through the dorsal column system, and motor-evoked potentials (MEPs), which monitor motor response to a trans-cranial stimulus. Decreases in amplitude and latency of the circuits are recorded, however diminished signal amplitudes are more sensitive for neurologic injury, and decreases of of >50-60% being highly concerning. The wake-up test involves reversal of anesthesia so that an intra-operative neurologic examination can be performed.
Devlin et al. reviewed the basic science and practice of neurophysiologic monitoring in spine surgery. They proposed an algorithmic approach to managing intraoperative alerts which include discontinuation of inhalational anesthetics, increasing the MAP to >90 mmHg, discontinuing instrumentation, and performing a wake-up test if neurologic signals fail to normalize.
Herdmann et al. reviewed the practice of neurophysiologic monitoring and the effects of anesthesia upon signal transduction. They report that anesthesia affecting a neuron's intrinsic excitability can alter the results of monitoring. Inhalational anesthetics and decreased MAPs can be responsible for decreased amplitudes.
Vitale et. al. developed a consensus-based intraoperative checklist for management of lost neuromonitoring signals. In this checklist, the first steps across the surgical and anesthetic teams should include: stop the case and announce signal losses to the room, optimize the mean arterial pressure, discuss the status of anesthetic agents, and discuss reversible surgical actions just prior to signal loss.
Incorrect

Question 25

Which of the following is helpful on physical examination to diagnose a fixed posterior shoulder dislocation? Review Topic

Explanation

The apprehension sign and Jobe relocation test are helpful for the diagnosis of anterior shoulder instability. The sulcus sign provides information on the status of the rotator interval. The jerk test is helpful for the diagnosis of posterior instability, but a fixed posterior shoulder dislocation is associated with loss of external rotation. Since an AP radiograph may miss this diagnosis, an axillary view should be obtained on patients with a shoulder injury.

Question 26

A 56-year-old woman undergoes an arthroscopic rotator cuff repair for a two-tendon retracted tear (supraspinatus and infraspinatus), requiring the use of four suture anchors placed in a double row technique. At her 1 month follow-up visit, what is the appropriate recommendation for her continued rehabilitation program? Review Topic

Explanation

Regardless of the technique of rotator cuff repair, the biology of tendon healing remains the same. Therefore, the repaired muscle tendon(s) must be protected from stress for a minimum of 6 weeks and more likely 8 weeks in a large two-tendon tear such as this patient had repaired. Therefore, at the 1 month follow-up visit, the patient should continue strict passive motion exercises and should perform no strengthening activities. Deltoid strengthening cannot be isolated from rotator cuff strengthening; therefore, deltoid strengthening is inappropriate as well. Because the infraspinatus is the primary shoulder external rotator, it should not be strengthened for 6 to 8 weeks. Supraspinatus strengthening at this time frame would likely ensure its disruption and result in failure of the surgery. Any resistance training at 1 month from surgery would likely result in tendon failure at the tendon-bone interface. The obligatory need to protect the muscles during healing will predictably result in atrophy but it is easier to strengthen healed muscles than it is to strengthen muscle/tendon units that have failed to heal.

Question 27

Which of the following illustrations shown in Figures 21a through 21e correctly shows the projection of the sacroiliac joint on the outer table of the ilium?

Explanation

DISCUSSION: The projection of the sacroiliac joint on the outer surface of the ilium should be well understood to avoid violation of the joint during bone graft harvesting and to help in insertion of the screw across the joint. The sacroiliac joint has superior and inferior limbs. The average lengths of the superior and inferior limbs are 4.4 cm and 5.6 cm, respectively. The average width of each limb is 2.0 cm. The average distance from the longitudinal axis of the superior limb to the posterior superior iliac spine is 5.5 cm. The average longitudinal axis of the inferior limb is 1.2 cm superior to the inferior margin of the posterior inferior iliac spine. The average angle between the two axes is 93 degrees. Figure 21c most closely shows the projection of the sacroiliac joint on the outer table of the ilium.
REFERENCES: Waldrop JT, Ebraheim NA, Yeasting RA, Jackson WT: The location of the sacroiliac joint on the outer table of the posterior ilium. J Orthop Trauma 1993;7:510-513.
Xu R, Ebraheim NA, Yeasting RA, Jackson WT: Anatomic considerations for posterior iliac bone harvesting. Spine 1996;21:1017-1020.

Question 28

The usual presentation of traumatic subscapularis tears is most often seen after forced

Explanation

DISCUSSION: The typical mechanism of injury is a fall and the patient grasps something to prevent the fall. This maneuver forces the arm into external rotation against resistance.
REFERENCES: Kreuz PC, Remiger A, Erggelet C, et al: Isolated and combined tears of the subscapularis tendon. Am J Sports Med 2005;33:1831-1837.
Gerber C, Hersche O, Farron A: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

Question 29

During anterior surgery on the cervical spine, at what level would the lateral dissection of the longus coli muscle most likely cause Horner’s syndrome?

Explanation

DISCUSSION: The sympathetic chain approaches the lateral border of the longus coli muscle at C6 and is more vulnerable to injury at this level. Injury to the chain will cause Horner’s syndrome, usually seen as unilateral ptosis.
REFERENCE: Ebraheim NA, Lu J, Yang H, Heck BE, Yeasting RA: Vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine.

Spine 2000;25:1603-1606.

Question 30

What is the most common complication of using structural bulk allograft to reconstruct segmental defects of the acetabulum?

Explanation

DISCUSSION: Both autograft and allograft have been used for complex acetabular reconstructions. They have been shown to be successful in the short term. However, graft resorption with collapse and subsequent cup loosening have occurred at high rates for both types of grafts, especially if reinforcement rings or cages are not used.
REFERENCES: Jasty M, Harris WH: Salvage total hip reconstruction in patients with major acetabular bone deficiency using structural femoral head allografts. J Bone Joint Surg Br 1990;72:63-67.
Paprosky WG, Magnus RE: Principles of bone grafting in revision total hip arthroplasty: Acetabular technique. Clin Orthop 1994;298:147-155.
Kwong LM, Jasty M, Harris WH: High failure rate of bulk femoral head allografts in total hip acetabular reconstructions at 10 years. J Arthroplasty 1993;8:341-346.

Question 31

…The patient underwent an uneventful arthroscopic repair and did well until 1 year later when she crashed during a race. She tore her anterior cruciate ligament (ACL) and underwent reconstruction. Followup after her successful ACL reconstruction reveals complaints of new shoulder pain and posterior instability from using crutches after her ACL surgery. A new MRI scan is shown in Figure 24. What factors are most likely associated with this patient’s recurrence?

Explanation

Question 32

A 31-year-old woman underwent a left Kidner procedure 3 months ago. She now has pain overlying the medial column of the foot. She withdraws the foot when touching of the medial foot is attempted. Examination reveals allodynia, pain, hyperalgesia, and edema of the medial foot. What is the most likely diagnosis?

Explanation

Patients with reflex sympathetic dystrophy (RSD) have a history of trauma, minor rather than major (eg, Colles fracture), in about 50% to 65% of cases. The condition may also follow a surgical procedure. Patients usually have symptoms and signs of RSD including: pain, described as burning, throbbing, shooting, or aching; hyperalgesia; allodynia; and hyperpathia. There are trophic changes within 10 days of onset of RSD in 30% of the extremities affected, including stiffness and edema and atrophy of hair, nails, and/or skin. Finally there can be autonomic dysfunction, such as abnormal sweating, either in excess or anhydrosis, heat and cold insensitivity, or redness or bluish discoloration of the extremities. Shingles, also called herpes zoster or zoster, is a painful skin rash caused by the varicella zoster virus (VZV). VZV is the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays in the body. Usually the virus does not cause any problems; however, the virus can reappear years later, causing shingles. Charcot arthropathy is a progressive condition of the musculoskeletal system that is characterized by joint dislocations, pathologic fractures, and debilitating deformities. This disorder results in progressive destruction of bone and soft tissues at weight-bearing joints; in its most severe form, it may cause significant disruption of the bony architecture. In patients with diabetes, the incidence of acute Charcot arthropathy of the foot and ankle ranges from 0.15% to 2.5%. Acute Charcot arthropathy almost always appears with signs of inflammation. Profound unilateral swelling, an increase in local skin temperature (generally, an increase of 3° to 7° above the nonaffected foot's skin temperature), erythema, joint effusion, and bone resorption in an insensate foot are present. These characteristics, in the presence of intact skin and a loss of protective sensation, are often pathognomonic of acute Charcot arthropathy. Cellulitis is an infection of the skin. Examination would reveal erythema, edema, and pain. Osteomyelitis is an infection of the bone. Examination may reveal edema, drainage, and pain.

Question 33

Based on the findings seen in the radiograph in Figure 26, emergent management should consist of

Explanation

DISCUSSION: The radiograph shows a volarly dislocated lunate. Initial emergent treatment of perilunate dislocations should consist of closed reduction and splinting, especially if the patient exhibits median nerve compression. Open reduction and pinning or ligament repair are necessary but are not emergent. A dorsal approach is sometimes required for ligament repair or bony visualization; however, this can be done in a more semi-elective manner.
REFERENCES: Isenberg J, Prokop A, Schellhammer F, et al: Palmar lunate dislocation. Unfallchirurg 2002;105:1133-1138.
Ruby LK: Fractures and dislocations of the carpus, in Browner BD, Jupiter JB (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 1367-1372.

Question 34

After trial placement of components in a primary total knee arthroplasty, the knee is unable to come to full extension, but the flexion gap is appropriately balanced. After adequate soft-tissue releases have been performed, what is the next most appropriate action to balance the reconstruction?

Explanation

DISCUSSION: The reconstruction requires additional resection of the distal femur to allow increased extension while maintaining the current flexion gap tension. Resecting more proximal tibia or decreasing the tibial polyethylene thickness will decrease flexion tension as well as extension tension. Adding posterior femoral augments and using a larger femoral component will increase flexion tension.
REFERENCES: Ayers DC, Dennis DA, Johanson NA, et al: Common complications of total knee arthroplasty. J Bone Joint Surg Am 1997;79:278-311.
Pelicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 281-286.

Question 35

This medication, a factor Xa inhibitor, currently is not approved for venous thromboembolism (VTE) prophylaxis.

Explanation

DISCUSSION
Warfarin has a long clinical track record and is well known among most physicians. It is a vitamin K antagonist that can be monitored with prothrombin time (INR) testing and reversed with vitamin K and fresh frozen plasma if needed. Newer oral anticoagulants are becoming more common and offer the advantage of being rapidly active without a need for monitoring. These oral anticoagulants are not reversible, which can complicate the treatment of patients who present with bleeding or require surgery. Dabigatran (Pradaxa) is a direct thrombin inhibitor that is approved for stroke prevention in atrial fibrillation. It is not reversible, and a surgical delay of 24 to 48 hours is recommended for all but emergent surgeries. A longer delay is recommended with renal insufficiency. Rivaroxaban (Xarelto) is an oral factor Xa inhibitor that is approved for atrial fibrillation and the treatment of VTE and deep vein thrombosis prophylaxis. It offers the advantage of daily dosing. It
is not reversible and a surgical delay of 36 to 48 hours is recommended. Apixaban (Eliquis) is another factor Xa inhibitor for which twice-daily dosing is required. It is currently approved for stroke prevention in atrial fibrillation, and a surgical delay of 36 to 48 hours is recommended.
RECOMMENDED READINGS
Gonsalves WI, Pruthi RK, Patnaik MM. The new oral anticoagulants in clinical practice. Mayo Clin Proc. 2013 May;88(5):495-511. doi: 10.1016/j.mayocp.2013.03.006. Review. Erratum in: Mayo Clin Proc. 2013 Jul;88(7):777. PubMed PMID: 23639500. View Abstract at PubMed Alquwaizani M, Buckley L, Adams C, Fanikos J. Anticoagulants: A Review of the Pharmacology, Dosing, and Complications. Curr Emerg Hosp Med Rep. 2013 Apr 21;1(2):83-97. Print 2013 Jun. PubMed PMID: 23687625. View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 100 AND 101
A 55-year-old woman slipped on ice while getting out of her car and sustained the injury shown in Figure 100.

Question 36

Which of the following conditions precludes performing a tendon transfer?

Explanation

DISCUSSION: Several conditions must be met before a tendon transfer has the potential to correct a dynamic deformity. If the target joint cannot be passively corrected to neutral, it indicates that a static joint contracture or bony deformity exists that cannot be corrected with a dynamic tendon transfer. While in-phase muscles are best, out-of-phase muscles are often the only muscles available for transfer. Tendon transfer should pull in a straight line to avoid tethering and late failure.
REFERENCES: Canale ST (ed): Campbell’s Operative Orthopaedics, ed 10. St Louis, MO, Mosby, 2003, pp 1283-1287.
Coughlin MJ, Mann RA: Disorders of tendons, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 786-861.

Question 37

An 18-month-old child was involved in a motor vehicle accident and sustained an isolated injury to the left upper extremity. A radiograph is shown in Figure 33. What is the most appropriate management for this injury?

Explanation

Humeral shaft fractures in infants and young children heal rapidly and have excellent remodeling potential. Appropriate treatment in this age group is immobilization with a coaptation splint and bandaging the arm to the thorax for comfort. Internal fixation is appropriate in multiple trauma, and external fixation may be useful when soft-tissue injury is extensive.

Question 38

A 15-year-old boy has hindfoot pain and very limited subtalar motion. A CT scan reveals a talocalcaneal coalition involving 40% of the middle facet. He has no degeneration of the posterior subtalar facet. Following failure of nonsurgical management, treatment should consist of

Explanation

DISCUSSION: The CT scan is an important test to help determine the extent of involvement of the talocalcaneal facet in a talocalcaneal coalition. In a young patient with no arthritis and joint involvement of less than 50%, resection of the coalition and fat pad interposition has been shown to be successful. A calcaneal osteotomy does not address the coalition. Subtalar arthroereisis has been used for treatment of a flexible flatfoot; tarsal coalition patients have a rigid-type flatfoot deformity.
REFERENCES: Sullivan JA: The child’s foot, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1077-1135.
Scranton PE Jr: Treatment of symptomatic talocalcaneal coalition. J Bone Joint Surg Am 1987;69:533-539.

Question 39

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

Explanation

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

Question 40

A 52-year-old, right hand dominant man comes for evaluation of right shoulder pain that has been intermittently bothering him for three months. The pain is worse with overhead activities. He denies any history of trauma. His range of forward elevation in the plane of the scapula is painful and is limited to 145 degrees, compared to 170 degrees on his unaffected side. A radiograph is shown in Figure A. He saw another orthopedist a month ago, who ordered an MRI, which showed a small, partial thickness supraspinatus tendon tear. He received a subacromial injection of lidocaine at that time which temporarily relieved 90 percent of the pain he felt with passive forward elevation of his shoulder past 90 degrees. Today he is requesting a subacromial injection of platelet rich plasma (PRP). You tell him that with regard to pain, function and range of motion, subacromial injection of PRP: Review Topic

Explanation

At one year, quality of life, pain, disability and shoulder range of motion are the same for patients treated with therapy and placebo versus patients treated with therapy and
PRP injection.
Platelet rich plasma has been used for the treatment of chronic tendinopathy in different areas with mixed results. No benefit to patients with symptoms of subacromial impingement has been demonstrated for subacromial injection of PRP, when added to a standard therapy program.
Kesikburun et al. conducted a randomized controlled trial in which patients with rotator cuff tendinopathy or partial rotator cuff tears were randomized to receive ultrasound-guided subacromial injection of either PRP or lidocaine, followed by a standard six-week therapy program. The authors found no difference in pain, range of motion or validated outcome scores at one year follow up.
Hall et al. reviewed sports medicine applications for PRP. At that time (2009), with regard to PRP, they concluded that there was "little clinical evidence for its use."
Ketola et al. sought to determine the effectiveness of subacromial decompression for the treatment of subacromial impingement syndrome. They randomized 140 patients to a supervised exercise program or arthroscopic subacromial decompression followed by a supervised exercise program. They found no clinically important differences between the two groups at 24 months follow up.
Figure A shows a right shoulder radiograph without osseous pathology. Incorrect answers:

Question 41

What is the most common nerve injury following a Monteggia fracture-dislocation of the forearm in adults?

Explanation

According to Rockwood and Green the most commonly injured nerve associated with a Monteggia fracture is the posterior interosseous nerve, a branch of the radial nerve.

Question 42

Up to what time frame are the risks minimized in anterior revision disk replacement surgery? Review Topic

Explanation

Revision anterior exposure within 2 weeks of total disk replacement incurs relatively little additional morbidity because adhesion formation is minimal. Surgeons should have a low threshold for revising implants that are clearly dangerously malpositioned or show early migration within this 2-week window. Beyond this time period, a revision strategy must be individualized to the particular clinical situation. A posterior fusion with instrumentation with or without a laminectomy is currently the most effective salvage procedure.

Question 43

Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

Explanation

DISCUSSION: The clinical photograph and radiograph show an iatrogenic flatback deformity with loss of the normal lumbar lordosis. The safest correction for this malalignment typically is performed away from the spinal cord in the midlumbar spine, most commonly at L2 or L3. The more distal the correction is performed, the more sagittal plane translation of the C7 plumb line with respect to the posterior sacrum. Performing the osteotomy too distally, however, makes it difficult to obtain adequate distal fixation.
REFERENCES: Shufflebarger HL, Clark CE: Thoracolumbar osteotomy for postsurgical sagittal imbalance. Spine 1992;17:S287-S290.
Murrey DB, Brigham CD, Kiebzak GM, et al: Transpedicular decompression and pedicle subtraction osteotomy (eggshell procedure): A retrospective review of 59 patients. Spine 2002;27:2338-2345.

Question 44

A 17-year-old girl has multidirectional instability of the shoulder. What is the most appropriate initial management? Review Topic

Explanation

Multidirectional instability of the shoulder is defined as symptomatic instability in two or more directions (anterior, posterior) but must include a component of inferior instability. Initial treatment should always include physical therapy and instruction in a home exercise program that emphasizes periscapular and rotator cuff strengthening to improve the dynamic stability of the glenohumeral joint. Immobilization has not been shown to be effective. Open capsular shift and arthroscopic capsular plication remain the surgical options when appropriate nonsurgical management fails (typically a minimum of 6 months of dedicated therapy and home program). Thermal capsulorrhaphy remains controversial but is not recommended by many clinicians because of reported complications including recurrent instability, axillary nerve injury, chondrolysis, and capsular injury.

Question 45

Early postoperative infections following primary total hip arthroplasty are most likely caused by which organism?

Explanation

DISCUSSION:
S aureus is the most common organism cultured in early (fewer than 4 weeks postoperative) periprosthetic infections. Methicillin-resistant S aureus is becoming a more common pathogen in certain patient populations. B hemolytic Streptococcus and some gram-negative infections can also be found in early postoperative infections. S epidermidis, S viridans, and P acnes are more commonly found in late (more
than 4 weeks postoperative) infections.

Question 46

A 19-year-old girl has had pain and swelling in the right ankle for the past 4 months. She denies any history of trauma. Examination reveals a small soft-tissue mass over the anterior aspect of the ankle and slight pain with range of motion of the ankle joint. The examination is otherwise unremarkable. A radiograph and MRI scan are shown in Figures 45a and 45b, and biopsy specimens are shown in Figures 45c and 45d. What is the most likely diagnosis?

Explanation

DISCUSSION: Giant cell tumors typically occur in a juxta-articular location involving the epiphysis and metaphysis of long bones, usually eccentric in the bone. The radiographs show a destructive process within the distal tibia and an associated soft-tissue mass. The histology shows multinucleated giant cells in a bland matrix with a few scattered mitoses. Osteosarcoma can have a similar destructive appearance but a very different histologic pattern with osteoid production. Ewing’s sarcoma also can have a diffuse destructive process in the bone. The histologic pattern of Ewing’s sarcoma is diffuse round blue cells. Aneurysmal bone cysts typically are seen as a fluid-filled lesion on imaging studies and have only a scant amount of giant cells histologically. Metastatic adenocarcinoma does not demonstrate the pattern shown in the patient’s histology specimen.
REFERENCES: Wold LA, et al: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, pp 198-199.
Simon M, et al: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 200-202.

Question 47

A consecutive series of 50 patients is randomized to receive either treatment A or treatment B. At a 10-year follow up, patient satisfaction with treatment is measured. Which of the following statistical calculations will provide the most information regarding the magnitude of possible differences between the two groups of patients?

Explanation

The confidence interval provides you a range of values that with a given level of confidence (usually 95%) contains the truc value. The confidence interval also reflects the limitations of data presented (i.e. if no sepsis occurred during a two year follow-up of THR, should we believe there will never be any recurrences of sepsis rate if we perform a hundred of these exchanges in the future.) Confidence internals are also essential when presenting long-term results based on survivorship curve. Without confidence intervals the picture presented to the readers can be misleading. In these cases more data are needed before any proelic (?) statements can be made.

Question 48

A 32-year-old man sustains a pilon fracture which is treated initially with a spanning external fixator, as shown in figure A. He is now 3 weeks from injury and skin swelling has subsided significantly. What is the most appropriate definitive treatment?

Explanation

External fixation is a temporizing treatment that allows the soft tissues to return to normal while maintaining your overall alignment. A fibular plate can help keep the length. Final treatment involves restoration of the tibial plafond articular surface which can only be done with ORIF +/- bone grafting. There is no role for primary arthrodesis in this young patient.
OrthoCash 2020

Question 49

An otherwise healthy 25-year-old man underwent a right anterior cruciate ligament reconstruction with a bone-patellar tendon-bone allograft. Routine preimplantation cultures of the allograft taken by the surgeon were positive for coagulase-negative Staphylococcus 5 days postoperatively. The patient has exhibited no evidence of clinical infection and his postoperative course has been uncomplicated during this time. What is the ideal management of this patient?

Explanation

The incidence of preimplantation positive cultures of musculoskeletal allografts used for anterior cruciate ligament reconstruction has varied between 4.8% and 13.3%. Interestingly, in none of the studies evaluating this issue did any of the patients
implanted with a "contaminated" graft develop a clinical infection. The results of the current literature suggest that the treatment of low-virulence organisms is unnecessary if no evidence of clinical infection exists. Preimplantation cultures do not appear to correlate with clinical infection. Therefore, the routine culture of allograft tissue is not recommended.

Question 50

A 14-year-old female has anal hemorrhoids. The General Surgical team has asked for a consultation in regards to her history of hand, wrist, and ankle joint pain and swelling over the past 3 years. Her physical examination reveals a swollen left wrist, right knee and left ankle. Lab work shows low hemoglobin, low albumin, elevated erythrocyte sedimentation rate (ESR), elevated antinuclear antibody (ANA) count, and a negative rheumatoid factor. Radiography of the affected joints are normal. What additional work up is required prior to her rectal surgery? Review Topic

Explanation

This patient has a diagnosis of Juvenile Idiopathic Arthritis (JIA). Flexion-extension c-spine radiographs should be ordered to rule out atlantoaxial instability prior to surgery.
JIA is a persistent autoimmune inflammatory arthritis lasting more than 6 weeks in a patient younger than 16 years of age. Serologic testing for this condition will usually show elevated ESR/CRP, low hemoglobin, low albumin and an elevated anti-nuclear antibody (ANA) count, as well as negative rheumatoid factor and positive HLA-B27. Radiographs of the c-spine should be considered in patients undergoing intubation as cervical kyphosis, facet ankylosis, and atlantoaxial subluxation is associated with this condition.
Punaro et al. reviewed rheumatologic conditions in children. The typical patient with
oligoarticular JIA is a white female (5:1, F:M), with a peak onset between ages 1 and 3 years. Nearly half of patients have monoarticular involvement, with the knee and ankle being most commonly involved. Uveitis is typically chronic, bilateral, and asymptomatic.
Borchers et al. reviewed juvenile idiopathic arthritis (JIA). They state that no laboratory test can conclusively establish a rheumatic diagnosis. They state that laboratory tests will be negative for systemic inflammation and antinuclear antibody (ANA) test has no use in screening for JIA, as it has a high false positive rate.
Incorrect Answers:

Question 51

A 19-year-old man has had intermittent progressive knee pain with ambulation and pain at night following a rodeo accident 4 weeks ago. Figures 4a through 4e show the radiographs, a bone scan, CT scan, and T2-weighted MRI scan. What is the most likely diagnosis?

Explanation

DISCUSSION: The imaging studies reveal a predominantly blastic lesion in the distal femur with posterolateral periosteal changes. The bone scan shows increased uptake in the distal femur, beyond that expected with radiography. Cross-sectional imaging confirms the presence of a soft-tissue mass extending from the lateral aspect of the femur, with diffuse intramedullary signal changes. This aggressive presentation, particularly in this location and in a patient of this age, is most consistent with osteosarcoma. The mineralization in the soft tissue strongly suggests neoplasm, not the reactive bony changes seen in an infectious process.
REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 175-186.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4. Philadelphia, PA, WB Saunders, 2002, vol 4, pp 3800-3833.

Question 52

Figure 10 is an anteroposterior pelvis radiograph of an 82-year-old man who had right hip pain that began 2 weeks ago but has since resolved with use of over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs). Currently he has no pain. Examination of his hip shows decreased internal rotation and minimal pain at the extremes of motion. What is the most appropriate treatment at this point?

Explanation

DISCUSSION
The radiograph shown is consistent with Paget disease of the bone. It demonstrates classic findings of widened lamellae and disorganized sclerotic and lytic areas. The cause is not clearly defined, but may be linked to a viral infection and subsequent alterations of osteoblastic and osteoclastic activity. Most patients are asymptomatic, and Paget disease is often found incidentally on radiographs. In this case, the patient’s symptoms likely were caused by hip arthritis, but Paget disease can cause diffuse bone pain in some cases. Considering the patient’s mild and short-term symptoms, observation and NSAID use is most appropriate. An MRI scan or biopsy is indicated if sarcomatous transformation is suspected, but this condition is rare and is associated with a substantial, unrelenting increase in pain. SPEP and UPEP are tests for multiple myeloma, of which the radiographs show no signs.
RECOMMENDED READINGS
Ralston SH. Pathogenesis of Paget's disease of bone. Bone. 2008 Nov;43(5):819-25. doi: 10.1016/j.bone.2008.06.015. Epub 2008 Jul 11. Review. PubMed PMID: 18672105.View Abstract at PubMed
Bonenberger E, Einhorn T. Metabolic bone diseases. In: Callaghan JJ, Rosenberg
AG, Rubash HE, eds. The Adult Hip. 2nd ed. Philadelphia, PA: Lippincott Williams 14
& Wilkins; 2007:514-533.

Question 53

A 2-year-old girl has had a swollen right knee for the past 7 weeks. There is no history of significant trauma, and she has not had a fever or been ill. Her parents report that she is stiff in the morning but otherwise does not report pain. A CBC count and erythrocyte sedimentation rate are normal. Treatment with naproxen at appropriate doses for the past 2 weeks has resulted in some improvement. Radiographs show only soft-tissue swelling. Examination reveals a healthy-appearing child with a warm and swollen right knee that is only slightly tender but lacks full extension by 20 degrees. What is the next most appropriate step in management?

Explanation

DISCUSSION: Up to 30% of children with juvenile rheumatoid arthritis (increasingly known now as juvenile idiopathic arthritis or JIA) already have potentially damaging uveitis at the time of diagnosis. This patient has typical oligoarticular JRA (JIA) and therefore is at significant risk for uveitis. MRI, radioisotope scanning, or an ACE level most likely would not provide additional useful diagnostic information because intra-articular derangement, osteomyelitis, or sarcoidosis are all unlikely. Arthrocentesis and triamcinolone hexacetonide joint injection might be indicated if continued use of nonsteroidal medication does not result in improvement, but should be held off for at least an additional 4 to 6 weeks to see if continued use of naproxen results in control of the arthritis.
REFERENCES: Wolf MD, Lichter PR, Ragsdale CG: Prognostic factors in the uveitis of juvenile rheumatoid arthritis. Ophthalmology 1987;94:1242.
Cassidy JT, Petty RE: Textbook of Pediatric Rheumatology. Philadelphia, PA, WB Saunders, 2001, p 220.
Chalom ED, Goldsmith DP, Koehler MA, et al: Prevalence and outcome of uveitis in a regional cohort of patients with juvenile rheumatoid arthritis. J Rheumatol 1997;24:2031-2034.

Question 54

What is the most common primary malignant tumor of bone in childhood?

Explanation

DISCUSSION: Osteosarcoma is the most common primary malignant tumor of bone in childhood, followed by Ewing’s sarcoma. Rhabdomyosarcoma is a soft-tissue sarcoma of childhood. Chondrosarcoma rarely occurs in childhood. Osteochondromas are benign tumors of the bone.
REFERENCES: Simon M, Springfield D, et al: Osteogenic Sarcoma: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, p 226.
Wold LA, et al: Osteogenic Sarcoma: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, pp 14-15.

Question 55

A 40-year-old patient who has a type II odontoid fracture is placed in a halo vest for 12 weeks; however, current radiographs show no evidence of healing. The next most appropriate step in management should consist of

Explanation

DISCUSSION: Because nonsurgical managment has failed and a significant number of type II odontoid fractures will go on to a nonunion, the salvage treatment of choice is posterior fusion at C1-2. Odontoid screws are contraindicated in patients with a chronic nonunion, which this patient has at the end of 3 months.
REFERENCES: Montesano PX: Anterior and posterior screw and plate techniques used in the cervical spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery, ed 2. Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1743-1761.
Bohler J: Anterior stabilization for acute fractures and non-unions of the dens. J Bone Joint Surg Am 1982;64:18-27.
Anderson PA, Steinmann JC: Internal fixation of the cervical spine, in Frymoyer JW (ed): The Adult Spine, Principles and Practice, ed 2. Philadelphia, PA, Lippincott Raven, 1997, pp 1119-1147.

Question 56

A 19-year-old collegiate lacrosse player has bilateral lower extremity pain during training runs and practice sessions. She says her pain is only associated with activity, always begins 4 to 5 minutes into an activity, and resolves within 10 minutes after activity cessation. She reports a feeling of numbness and tingling in her first- and second-toe web space with continued activity. She has no pain while at rest and has tried nonsteroidal anti-inflammatory drugs, ice baths, and rehabilitation techniques with her athletic trainers without experiencing noticeable changes. Which test has the highest specificity and sensitivity for the pathology suspected?

Explanation

DISCUSSION
Chronic exertional compartment syndrome (CECS) is an uncommon cause of pain that is most often encountered in athletes or military populations. The diagnosis is suggested by pain after the start of the activity with resolution of symptoms when the activity stops. Traditionally, the diagnosis was established by measuring intracompartment pressures at 1 and 5 minutes of
activity. Roscoe and associates have shown that using continuous pressure monitoring during the activity until pain forces subjects to stop provides higher sensitivity and specificity than the traditional diagnostic technique. Palpating the leg is not as sensitive or specific as direct pressure monitoring. Although certain changes can be seen on MRI in CECS, this is not the diagnostic study of choice.

Question 57

Figures 18a and 18b show the radiographs of a patient who has pain with walking. On careful questioning, it is determined that the discomfort occurs at push-off, or when the patient attempts to climb stairs. What nonsurgical option is most likely to ameliorate the symptoms?

Explanation

DISCUSSION: The patient has a malunion of an attempted open reduction of a Lisfranc dislocation. The pain occurs during the terminal stance phase of gait as load is being transferred from the hindfoot to the forefoot. The bending moment can be best neutralized with shoe modification with a cushioned heel and rocker sole, which best unloads the tarsal-metatarsal junction.
REFERENCES: Bono CM, Berberian WS: Orthotic devices: Degenerative disorders of the foot and ankle. Foot Ankle Clin 2001;6:329-340.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 58-63.

Question 58

When considering a flexor digitorum longus tendon transfer as part of the surgical treatment in patients with symptomatic flatfoot deformity caused by posterior tibial tendon insufficiency, which of the following patients is the most appropriate candidate?

Explanation

DISCUSSION: Transfer of the flexor digitorum longus tendon is a common technique combined with other procedures to treat patients with posterior tibial tendon insufficiency. However, it is contraindicated in patients with a fixed hindfoot deformity, hypermobility, or neuromuscular compromise. It is relatively contraindicated in patients who are obese, and those older than age 60 to 70 years.
REFERENCES: Pedowitz WJ, Kovatis P: Flatfoot in the adult. J Am Acad Orthop Surg 1995;3:293-302.
Mann RA: Surgery of the Foot and Ankle, ed 6. St Louis, MO, Mosby-Year Book, 1993, pp 167-296.

Question 59

A 37-year-old recreational tennis player undergoes surgery for tennis elbow. Following surgery, she describes clicking and popping on the lateral aspect of the elbow. A lateral pivot shift test is positive. What is the most likely cause of her symptoms?

Explanation

DISCUSSION: The patient has a posterolateral rotatory instability (PLRI) of the elbow that is most likely the result of iatrogenic injury to the lateral ulnar collateral ligament, the main ligament implicated in PLRI. The anterior band of the medial collateral ligament is implicated in valgus instability. Injury to the radial nerve is unlikely, and the lateral radial collateral ligament makes less of a contribution to elbow stability than does the ulnar component. While the origin of the extensor carpi radialis brevis may contribute to elbow stability, it is not as important a stabilizer as the lateral ulnohumeral ligament.
REFERENCES: O’Driscoll SW, Morrey BF: Surgical reconstruction of the lateral collateral ligament, in Morrey BF (ed): The Elbow. Philadelphia, PA, Lippincott, Williams and Wilkins, 1994, pp 169-182.
O’Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow. J Bone Joint Surg Am 1991;73:440-446.

Question 60

Avascular necrosis

Explanation

Slide
A 9-year-old girl sustains an injury (Slide) as a result of a fall. What is her risk of avascular necrosis:

Question 61

The safest surgical approach to the insertion of the tibial posterior cruciate ligament uses the interval between which of the following muscles?

Explanation

DISCUSSION: Burks and Schaffer described an approach to the tibial insertion of the posterior cruciate ligament that uses the interval between the semimembranosus and the medial gastrocnemius. The medial gastrocnemius muscle is retracted laterally and protects the neurovascular bundle. This approach is used to repair an avulsion of the posterior cruciate ligament tibial attachment or for performing a posterior cruciate ligament tibial

inlay reconstruction.
REFERENCES: Berg EE: Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;8:95-99.
Burks RT, Schaffer JJ: A simplified approach to the tibial attachment of the posterior cruciate ligament. Clin Orthop 1990;254:216-219.

Question 62

-A 42-year-old patient with a right distal radius fracture underwent open reduction and internal fixation. To reduce the likelihood of complex regional pain syndrome, the most appropriate medication is

Explanation

Question 63

A 14-year-old girl reports hip pain that is exacerbated by weight bearing. A radiograph and biopsy specimen are shown in Figures 16a and 16b. The best course of management should be

Explanation

DISCUSSION: The patient has a unicameral bone cyst. Because the subtrochanteric part of the femur is a high-stress region, the treatment of choice is bone curettage and grafting.
REFERENCES: Azouz EM, Karamitsos C, Reed MH, Baker L, Kozlowski K, Hoeffel JC: Types and complications of femoral neck fractures in children. Pediatr Radiol 1993;23:415-420.
Hecht AC, Gebhardt MC: Diagnosis and treatment of unicameral and aneurysmal bone cysts in children. Curr Opin Pediatr 1998;10:87-94.

Question 64

What role does quorum sensing play in the development of a bacterial biofilm?

Explanation

The development of a bacterial biofilm is a 2-stage process. The first step is the adhesion of individual bacteria to a substrate regulated by adhesions. After several bacteria have attached, quorum sensing (cell-to-cell communication) allows maturation of the biofilm and expression of genes that activate virulence factors. This can also increase the antibacterial resistance of the bacteria. Planktonic bacteria are individual free-moving bacteria.

Question 65

The Chi-square test is most appropriate for which of the following?

Explanation

The Chi-square test is most appropriately used for comparing proportions of categorical or ordinal data.
When considering which statistical test to use the investigator must consider how many groups are being compared, and if the data collected is numerical or categorical, and parametric or non-parametric. When the study is comparing proportions of categorical data the appropriate test will be either a Chi-square test, or a Fisher exact test. The Fisher exact test is preferred when there is less than 5 data points in any group being compared.
Illustration A is a flow chart demonstrating how to determine which statistical test is most appropriate.
Incorrect answers:
with the Mann-Whitney U test Answer 3: Comparing means of parametric data between 3 or more groups is best done with Analysis of variance (ANOVA) Answer 5: Comparing proportions of categorical data between groups when at least one group has less than 5 samples or data points is best done with the Fisher exact test

Question 66

Within the menisci, the majority of the large collagen fiber bundles are oriented in what configuration?

Explanation

DISCUSSION: The majority of large collagen fibers within the menisci are oriented circumferentially. It is these fibers that develop the hoop stress with compressive loading of the menisci. Most meniscal tears are longitudinal and occur between these circumferential fibers.
REFERENCES: Mow VC, et al: Structure and function relationships of the menisci of the knee, in Mow VC, Arnoczky SP, Jackson DW (eds): Knee Meniscus: Basic and Clinical Foundations. New York, NY, Raven Press, 1992, pp 37-57.
DeHaven KE, Arnoczky SP: Meniscus repair: Basic science, indications for repair, and open repair. Instr Course Lect 1994;43:65-76.

Question 67

An 76-year-old woman falls from standing and sustains the injury shown in Figure A. Her most recent T score was -1.9, 3 months prior to presentation. If labwork were performed, which values would be consistent with her bone density score?

Explanation

In osteopenia, elevated parathyroid hormone (PTH), high alkaline phosphatase as well as low calcium (Ca), phosphorus and vitamin D would be expected.
In the setting of osteopenia/osteoporosis, there is a positive feedback to increase PTH in response to low serum calcium levels. In response, there is a corresponding increase in alkaline phosphatase and decrease in phosphorous and circulating vitamin D levels.
Fraser writes a concise, yet thorough synopsis on primary and secondary hyperparathyroidism. In the article, the summary regarding osteopenia/osteoporosis (typically a state of hypovitamin D) begins by stating an initial state of decreased ionised calcium, which increases PTH, results in 3 primary effects: an attempt to increase gut absorption of Ca, mobilize Ca from the bone via osteoclasts and activate vitamin D at the kidney (1,25-vitamin D).
Figure A exhibits a left femoral neck fracture, which is a fragility fracture associated with poor bone density. Illustration A is a figure from Fraser's article exhibiting the feedback loop from the hypothalamus, pituitary, adrenal/glandular axis.
Incorrect answers:

Question 68

The great medullary artery, also known as the Adamkiewicz artery, originates from which of the following arteries?

Explanation

DISCUSSION: The great medullary artery originates as a direct or indirect branch of the left posterior intercostal artery, usually between T8 and T12. It becomes intradural and crosses over one to three disk spaces before turning to the midline where it anastomoses with the anterior spinal artery. Injury to this artery can result in devastating ischemia of the lower spinal cord.
REFERENCES: Lu J, Ebraheim NA, Biyani A, Brown JA, Yeasting RA: Vulnerability of great medullary artery. Spine 1996;21:1852-1855.
Rogers FB, Osler TM, Shackford SR, Wald SL: Isolated stab wound to the artery of Adamkiewicz: Case report and review of the literature. J Trauma 1997;43:549-551.

Question 69

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

Explanation

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

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

Question 70

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

Explanation

Most studies have shown that total shoulder arthroplasties yield better pain relief and improved forward elevation when compared to hemiarthroplasty in patients with rheumatoid arthritis. Although rotator cuff tears are more common in this patient population, this patient has good forward elevation and no significant superior migration of the humeral head; therefore, a reverse arthroplasty is not indicated. The arthritis is too advanced in this patient to consider arthroscopy, but in less advanced cases it can improve range of motion and decrease pain. Metal-backed glenoid components have shown higher rates of loosening.

Question 71

A 14-year-old boy sustained a 100% displaced distal radius Salter-Harris type II fracture. Neurologic examination demonstrates normal motor examination and two-point discrimination. He undergoes fracture reduction to the anatomic position with the application of a long arm cast. Postreduction he reports increasing hand and wrist pain with diminution of two-point discrimination to 10 mm over the index and middle fingers over the next several hours after surgery. The cast is bivalved and the padding released relieving all external pressure over the arm. Reevaluation reveals increasing sensory deficit over the affected area. What is the next most appropriate management intervention?

Explanation

DISCUSSION: The patient has an evolving acute carpal tunnel syndrome. Initial management for this injury is to relieve all external pressure that may elevate the neural compression. Surgical decompression of the median nerve at the carpal tunnel is the optimal intervention. Further nonsurgical interventions (cast removal or further bivalving) are insufficient to alleviate the neural compression.
REFERENCES: Waters PM, Mih AD: Fractures of the distal radius and ulna, in Beaty JH, Kasser JR (eds): Fractures in Children, ed 6. Philadelphia, PA, Lippincott, 2006, p 361.
Paley D, McMurtry RY: Median nerve compression by volarly displaced fragments of the distal radius. Clin Orthop Relat Res 1987;215:139-147.

Question 72

When discussing treatment options with a 35 year-old healthy male with an isolated, closed tibial shaft fracture, the surgeon should inform him that in comparison to closed treatment, the advantages of intramedullary nail fixation include all of the following EXCCEPT?

Explanation

DISCUSSION: All of the answer choices are correct except #3. Intramedullary nailing can increase the risk of compartment syndrome.
In a study of 94 tibial fractures, Finkemeier reported 10 (11%) had compartment syndromes. Three of the 10 patients developed the compartment syndrome postoperatively.
In comparing IM nailing to non-op, Bone et al showed that IM nailing had a shorter time to union (mean, 18 vs 26 weeks; p = 0.02), lower non-union rate (2% vs 10%), decresed incidence of shortening (2% vs 27%), and quicker return to work (mean, 4 vs 6.5 months), but no difference in compartment syndrome (0% in both groups).
The classic article cited by Sarmiento el al. reported that closed treatment with use of a prefabricated functional below-the-knee brace was effective in a study of 1000 closed diaphyseal fractures of the tibia with an incidence of nonunion of only 1.1%. However, those authors had very strict criteria for use of the fracture-brace (exclusion criteria included intact fibular, shortening >2cm).

Question 73

A 48-year-old man is brought in by emergency services after falling down a flight of stairs. He complains of weakness in both hands. Examination reveals weak grip bilaterally. Injury CT scans are shown in Figure A. What is the most appropriate treatment option? Review Topic

Explanation

This patient has ankylosing spondylitis (AS) and has suffered a shear fracture through C5-6. Due to the presence of neurological deficits, posterior decompression and fusion with a long construct (such as from C3-T2) is indicated.
The C-spine is the most common site of fracture in AS and is most susceptible to hyperextension injuries. When surgical intervention is required, multiple points of fixation both above and below the fracture are necessary. This is due to co-existing osteoporosis and abnormally increased forces from long lever arms of the ankylosed spine, both of which make the construct susceptible to failure and screw pullout.
Kubiak et al. reviewed the orthopaedic management of AS. They report bone scan, MRI or fine-cut CT is necessary because fractures are often missed on plain x-rays because of distortion of anatomy or difficulty with positioning.
Whang et al. reviewed spinal injuries in 12 patients with AS and 18 patients with DISH. Most injuries involved C5-C7. Patients with AS were more likley to have severe neurologic injury (41% ASIA A) than DISH (44% ASIA E). There was 81% good-excellent outcome and 4 deaths related to halo vest use.
Figure A is a sagittal CT reconstructed image showing a nondisplaced shear fracture through the C6 vertebral body and C5 posterior elements. Illustrations A and B are postop AP and lateral radiographs showing posterior decompression and C3-T2 fusion with lateral mass fixation in the cervical spine and pedicle screw fixation in the upper thoracic spine.
Incorrect Answers:
performed through a posterior approach. If there is significant osteoporosis and the risk of construct failure is high, a 360-approach may be necessary.

Question 74

You are evaluating a patient with recurrent patellar instability who has failed conservative management. MRI demonstrates articular cartilage loss in the patella. In addition to a cartilage restoration procedure, you recommend the procedure depicted in Figures A and B. Which of the following imaging findings best supports your decision? Review Topic

Explanation

A tibial tubercle-trochlear groove (TT-TG) distance > 20mm is highly associated with patellar instability secondary to rotational malalignment and is an indication for anteromedialization of the tibial tubercle (AMZ), pictured in Figures A and B, to enhance patellofemoral stability and decrease patellofemoral contact pressures in the setting of cartilage restoration procedures.
Recurrent patellar instability is often associated with chondral lesions of the patellofemoral joint. In addition to managing the cartilage injury, the underlying etiology of the instability must also be addressed to ensure a successful outcome. Patellar instability may arise from coronal or rotational malalignment, patella alta, trochlear dysplasia or damage to soft tissue restraints including the medial patellofemoral ligament (MPFL). Rotational malalignment, defined by a TT-TG distance > 20mm, can be addressed by AMZ. Medialization of the tubercle restores a normal TT-TG distance while anteriorization of the tubercle unloads patellofemoral contact forces.
Beck et al performed a cadaveric study measuring patellofemoral contact pressures on the trochlear surface following AMZ. They found that anteromedialization decreased the mean contact pressures and shifted contact pressures to the medial trochlea. The authors concluded that while this procedure successfully unloads the lateral trochlea, it likely has minimal benefit for central chondral defects and may be detrimental for medial chondral defects where contact pressures are increased.
Strauss et al authored a review article detailing the surgical treatment options for patellofemoral cartilage lesions, including concomitant realignment/unloading procedures. AMZ is designed to correct rotational malalignment while unloading the patellofemoral compartment in the setting of cartilage restoration surgery. While AMZ has demonstrated good outcomes for lesions located in the lateral facet or distal
pole of the patella, poor outcomes have been seen with medial facet or central trochlear lesions.
Figures A and B are the AP and lateral radiographs, respectively, of a knee s/p AMZ, also know as a Fulkerson procedure. Illustration A is an algorithm detailing the approach to recurrent patellar instability in both skeletally immature and mature patients. Illustration B demonstrates how to measure the TT-TG distance, the distance between two lines drawn perpendicular to the posterior condylar axis to the tibial tubercle and deepest portion of the trochlear groove (normal 8-10mm). Illustration C depicts the measurement of the femoral trochlear angle or sulcus angle (normal 137°
+/- 8°). Illustration D shows how to measure lateral patellar tilt (normal < 5°). Illustration E is a postoperative radiograph after AMZ. A long (> 5cm) and thick (> 0.75cm) osteotomy cut is required to allow adequate fixation with two screws.
Incorrect Responses:

Question 75

A 36-year-old woman has neck pain in the upper cervical region and occipital discomfort after being involved in a motor vehicle accident. Examination reveals no forehead or scalp lacerations. The neurologic examination is normal. A CT scan shows no evidence of bony injury. Figures 39a and 39b show a lateral radiograph and an MRI scan. Management should consist of

Explanation

DISCUSSION: The lateral radiograph shows 8 mm of atlantoaxial translation. In the absence of a bony injury, this represents rupture of the transverse atlantal ligament. The MRI scan reveals soft-tissue swelling posterior to the odontoid and a high intensity zone in the atlanto-dens interval consistent with acute injury. These injuries require arthrodesis because nonsurgical measures will not provide stability. Techniques for C1-2 fusion include Gallie, Brooks, or triple wiring. Transarticular screw fixation across the C1-2 articulation provides the most rigid means of fixation and the highest arthrodesis rates but is technically demanding. Anterior C2-3 arthrodesis will not address the level of instability. The normal atlanto-dens interval is 3 mm in an adult and 4 mm in a child.
REFERENCES: Kurz LT: Transverse atlantal ligament insufficiency, in Clark CR (ed):

The Cervical Spine. Philadelphia, PA, Lippincott-Raven, 1998, pp 401-407.
Fielding JW, Cochran GB, Lansing JF III, et al: Tears of the transverse ligament of the atlas:

A clinical and biomechanical study. J Bone Joint Surg Am 1974;56:1683-1691.

Question 76

An adult with a distal humeral fracture underwent open reduction and internal fixation. What is the most common postoperative complication?

Explanation

DISCUSSION: Most patients lose elbow range of motion after open reduction and internal fixation of a distal humeral fracture. Ulnar nerve dysfunction, nonunion, and infection all occur less commonly.
REFERENCES: Webb LX: Distal humerus fractures in adults. J Am Acad Orthop Surg 1996;4:336-344.
McKee MD, Wilson TL, Winston L, et al: Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. J Bone Joint Surg Am 2000;82:1701-1707.

Question 77

What structure is marked Q in the diagram of the brachial plexus shown in Figure 22?

Explanation

DISCUSSION: From proximal to distal, the brachial plexus is divided into roots, trunks, divisions, and cords before forming specific peripheral nerve branches. The structure marked Q is called the posterior cord because it lies posterior to the axially artery at the level of the cords. Its terminal branches are the upper subscapular (V), thoracodorsal (W), lower subscapular (X), axillary (F), and radial (G) nerves.
REFERENCES: Anderson JE (ed): Grant’s Atlas of Anatomy, ed 7. Baltimore, MD, Williams and Wilkins, 1978, pp 6-24.
Last RJ: Anatomy: Regional and Applied, ed 6. London, England, Churchill Livingstone, 1978, p 63.

Question 78

A 26-year-old man is brought to the emergency department unresponsive and intubated after being found lying on the side of the road. He has a Glasgow Coma Scale score of 6. A chest tube has been inserted on the right side of the chest for a pneumothorax. An abdominal CT scan reveals a small liver laceration and minimal intraperitoneal hematoma. A pneumatic antishock garment (PASG) is on but not inflated. He has bilateral tibia fractures. A pelvic CT scan shows an anterior minimally displaced left sacral ala fracture and left superior and inferior rami fractures. He has received 2 L of saline solution and 4 units of blood but remains hemodynamically unstable. What is the next most appropriate step in management?

Explanation

DISCUSSION: There is no identifiable thoracic, abdominal, or long bone source of ongoing bleeding. The patient has a lateral compression Burgess-Young type I pelvic ring injury. This injury does not increase the pelvic volume because it is not unstable in external rotation. Application of a PASG, a pelvic clamp, or an external fixator may be helpful if the patient has a pelvic injury that is unstable in external rotation or translation but would be of little use in this injury pattern. Persistent hemodynamic instability after administration of 4 units of blood is the decision point where most authors would recommend angiography and embolization. If the pelvis is unstable in external rotation or translation, inflation of the PASG trousers or application of an external fixator is recommended before angiography. Attributing the hemodynamic instability to the head injury before ruling out the pelvis as a source is not indicated.
REFERENCES: Burgess AR, Eastridge BJ, Young JW, et al: Pelvic ring disruptions: Effective classification system and treatment protocols. J Trauma 1990;30:848-856.
Evers BM, Cryer HM, Miller FB: Pelvic fracture hemorrhage: Priorities in management. Arch Surg 1989;124:422-424.
Flint L, Babikian G, Anders M, Rodriguez J, Steinberg S: Definitive control of mortality from severe pelvic fracture. Ann Surg 1990;211:703-707.

Question 79

A 47-year-old woman has had a 1-month history of left hip and medial thigh pain that is exacerbated by sitting. Laboratory studies show a total protein level of 8.2 g/dL (normal 6.0 to 8.0) and an immunoglobulin G (IGG) level of 2,130 mg/dL (normal 562 to 1,835). A radiograph, CT scan, and biopsy specimen are shown in Figures 38a through 38c. What is the most likely diagnosis?

Explanation

DISCUSSION: The laboratory studies and histology are both consistent with myeloma. Infection should show white blood cells other than plasma cells on histology. Lymphoma would show lymphocytes, not plasma cells. The lack of bone formation on the imaging studies and the lack of osteoid on histology rule out osteosarcoma. The cells have too much cytoplasm and nuclear chromatin to be Ewing’s sarcoma cells.
REFERENCE: Mirra J: Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia, PA, Lea & Febiger, 1989, vol 2, ch 16.

Question 80

Following a partial muscle laceration, keeping the affected extremity immobilized for 2 weeks before starting an exercise program will likely lead to: Review Topic

Explanation

Muscle lacerations immobilized for 2 weeks would likely experience significant muscle atrophy affecting final functional outcome. For muscle injuries, including partial lacerations, current literature suggests the affected extremity should be immobilized no more than 3-5 days, followed by a progressive strengthening and stretching program.
Healing a muscle injury involves two competing processes: regeneration of muscle fibers and formation of granulation tissue. Starting motion too soon after injury may increase the area of fibrous scar, and limit the ability of new muscle fibers to penetrate this area. Prolonged immobilization limits scar production but penetrating muscle fibers will lack appropriate orientation, and the muscle as whole begins to atrophy. Three to 5 days of immobilization has been shown to limit scar tissue production
while the early motion helps generate appropriately organized muscle fibers and maintain strength and range of motion.
Järvinen et al. present a review of muscle injury and healing. They found that immediate mobilization led to a large area of dense scar tissue that regenerating muscle fibers could not adequately penetrate. Prolonged immobilization allowed muscle fibers to regenerate but they lacked appropriate morphology. Following 3-5 days of immobilization they found less scar tissue, better penetration of regenerated muscle fibers, and the regenerated fibers were more well aligned with the uninjured fibers surrounding them.
Menetrey et al. present a mouse model of muscle laceration comparing a short period of immobilization (5 days) to suture repair of the muscle. They found quicker healing and greater strength in the suture repair group. Tetanus strength at one month after injury was (compared to an uninjured control) 81% for sutured muscle, 35% for the early mobilization only group, and 18% for the prolonged immobilization group.
Illustration A is a histology section of lacerated muscle after 7 days of immobilization. The area is infiltrated with granulation tissue and few regenerating myofibers. Illustration B is a histology section of lacerated muscle after 14 days of immobilization. Further infiltration with granulation tissue and mononuclear cells can be seen with regenerating myofibers only at the periphery.
Incorrect answers:

Question 81

What is the most common reason for reoperation in total knee arthroplasty?

Explanation

DISCUSSION: Patellar problems currently constitute the largest number of complications after total knee arthroplasty, affecting between 8% and 35% of patients. These problems include patellar instability, fracture, component loosening, surface erosion, and pain. Malalignment, as an isolated reason for revision, is uncommon, yet it contributes to accelerated wear of the components. Joint instability affects up to 6% of patients, and the infection rate in knee arthroplasty is around 1% to 2%.
REFERENCES: Blasier RB, Matthews LS: Complications of prosthetic knee arthroplasty, in Epps CH (ed): Complications in Orthopaedic Surgery. Philadelphia, PA, JP Lippincott, 1994, pp 1066-1069.
Rand JA: The patellofemoral joint in total knee arthroplasty. J Bone Joint Surg Am 1994;76:612-620.
Wilson MG, Kelley K, Thornhill TS : Infection as a complication of total knee-replacement arthroplasty: Risk factors and treatment in sixty-seven cases. J Bone Joint Surg Am 1990;72:878-883.

Question 82

Figures 45a through 45c show the radiograph, CT scan, and MRI scan of a 15-year-old boy who has lateral ankle pain. What is the most likely diagnosis?

Explanation

DISCUSSION: The elongated anterior process of the calcaneus reaching distally toward the navicular is an abnormal finding. Instead of viewing the rounded, blunt distal anterior process of the calcaneus, a bridge extends to the navicular, albeit incomplete. These findings are consistent with a fibrous coalition. CT can reveal a stress fracture of the calcaneus, arthritis of the subtalar joint with subchondral cysts, or an os peroneal bone disruption in the peroneus longus, but those entities are not shown here. The plantar fascia is intact.
REFERENCES: Richardson EG: Sesamoids and accessory bones of the foot, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 702-732.
Oestreich AE, Mize WA, Crawford AH, et al: The “anteater nose”: A direct sign of calcaneonavicular coalition on the lateral radiograph. J Pediatr Orthop 1987;7:709-711.

Question 83

Which of the following is most commonly inherited as a X-linked recessive disorder? Review Topic

Explanation

Duchenne's muscular dystrophy is an X-linked recessive disorder.
Duchenne's muscular dystrophy is caused by a mutation in the dystrophin gene. X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed (1) in males (who are necessarily hemizygous for the gene mutation because they have only one X chromosome) and (2) in females who are homozygous for the gene mutation (i.e., they have a copy of the gene mutation on each of their two X chromosomes).
Zane reviewed paediatric neuromuscular disorders. Duchenne's muscular dystrophy patients will show markedly elevated CPK levels (10-200x normal). Muscle biopsy will show connective tissue infiltration, foci of necrosis and absent dystrophin with staining.
Illustration A shows an illustration of Gowers sign. This indicates weakness of the proximal muscles. It is characteristic of patients with Duchenne's muscular dystrophy.
Incorrect Answers:

Question 84

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

Explanation

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

Question 85

A 4-year-old boy sustains the injury shown in Figures 10a and 10b as a result of being hit and dragged by a car. Wound closure is best accomplished by

Explanation

The indications for a free flap coverage for the foot and ankle include loss of skin and subcutaneous tissue with exposed bone, tendon, and neurovascular structures and, on occasion, surgical hardware; local options are not available or feasible and coverage is necessary to provide
healing and survival of the underlying structures, prevent infection, and provide a durable and/or flexible cover. Furthermore, the standard cross-leg flap no longer is used because of significant problems with positioning and joint stiffness, and because it provides inadequate coverage material. For the various surfaces of the ankle and dorsum of the foot, very few local tissues are available to provide coverage when free skin grafting is insufficient. Thus, out of the possible answers, free rectus abdominis flap is the preferred response.

Question 86

A 30-year-old accountant and recreational softball player, who is seen at the end of his baseball season, reports a several month history of pain along the medial side of his dominant elbow. He cannot identify a specific injury and notes it only hurts when he throws the ball in from the outfield. Besides the pain, he remarks that his speed and distance while throwing have diminished considerably. Examination reveals tenderness along the medial elbow but no weakness or gross instability is found. Radiographs are normal. Based on the history, what is the most likely diagnosis? Review Topic

Explanation

Throwing athletes frequently develop medial collateral ligament sprain related to the repeated valgus stress that occurs on the medial elbow during the acceleration phase of throwing. This has the effect of not only causing pain, but also resulting in loss of velocity and distance during the throwing activity. The injury is generally well tolerated in most activities of daily living and only becomes problematic during the vigorous, stressful act of throwing. Absence of neurologic signs or symptoms makes ulnar nerve pathology unlikely. Pronator syndrome causes pain on the volar aspect of
the forearm during resisted forearm pronation and is not associated with the throwing motion in particular. Valgus extension overload may mimic medial collateral ligament injury, not varus extension injuries. Medial epicondylitis may be confused with ligament insufficiency but the examination and a history of pain only while throwing make this an unlikely diagnosis.

Question 87

Figure 67 shows the AP radiograph of both knees of a 26-year-old woman. A review of the patient’s medical record will most likely reveal a history of

Explanation

Avascular necrosis of the knee is associated with the use of corticosteroids or alcohol 90% of the time. Radiographically evident lesions progress until the necrotic cancellous bone collapses away from the subchondral plate, resulting in the classic crescent sign; earliest sign of mechanical failure of the condyles. Generally seen in a younger age group (less than 50 years old). Of patients with corticosteroid induced AVN of the knee; 81% have systemic lupus erythematosus, 9.5% inflammatory bowel disease, and 9.5% polymyositis.

Question 88

Which of the following best describes the course of the median nerve at the elbow?

Explanation

DISCUSSION: The median nerve courses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, and deep to the superficial head of the pronator teres muscle. The median nerve lies within the interval between the flexor digitorum superficialis muscle and the flexor digitorium muscle as it progresses toward the wrist.
REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2. Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.
Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System. Part 1, Anatomy, Physiology and Metabolic Disorders. West Caldwell, NJ, Ciba-Geigy, 1991, vol 8,

pp 46-47.

Question 89

Osteoporotic vertebral compression fractures are associated with Review Topic

Explanation

Osteoporotic vertebral compression fractures are associated with neurologic complications in less than 1% of patients. After the initial fracture however, patients have a 20% risk of further fractures. The mortality rate of patients with vertebral fractures exceeds that of patients with hip fractures when they are followed beyond 6 months.

Question 90

A further workup reveals elevations in serum cobalt and chromium levels and fluid collections surrounding the hip on MARS MR imaging. Revision THA is recommended. The most common complication following revision of a failed metal-on-metal hip arthroplasty is

Explanation

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

Question 91

A 14-year-old patient who has homocystinuria and is Risser 3 is referred for surgical treatment of scoliosis. In addition to the usual risks associated with posterior spinal fusion, the family should be advised that the patient ‘s underlying condition significantly increases the perioperative risk of

Explanation

Tendency towards venous and arterial thrombosis along with mental retardation, dislocation of the lens and skeletal changes resembling Marfan’s are all clinical features of homocystinuria. Homocysteine is toxic and causes endothelial cell damage. Increased platelet stickiness is also associated with the disease.
1 and 2 are concerns during spinal fusion but are not specific to this disease. 4 may occur with homocystinuria but is not related to spinal fusion. 5 occurs with PSF in the younger population because of the growth potential remaining.

Question 92

Figures 9a and 9b show the spinal radiographs of a 3-year-old child with short limb dwarfism. The lateral radiograph is obtained with maximal lumbar extension. Management should consist of

Explanation

DISCUSSION: The patient has kyphosis in association with achondroplasia. The AP radiograph shows decreased interpedicular distance at the lower lumbar vertebrae, a feature considered to be a distinctive sign of achondroplasia. Most patients with achondroplasia have kyphosis, and this usually resolves spontaneously. When the fixed component is greater than 30°, however, brace treatment is recommended. Spinal fusion is seldom required.
REFERENCE: Pauli RM, Breed A, Horton VK, Glinski LP, Reiser CA: Prevention of fixed angular kyphosis in achondroplasia. J Pediatr Orthop 1997;17:726-733.

Question 93

Which of the following best describes the recommended treatment for a 13-year-old pitcher with a painful chronic stress injury to the proximal humeral physis as confirmed on an MRI scan? Review Topic

Explanation

Little Leaguer's shoulder is a chronic stress injury to the proximal humerus growth plate. Imaging findings demonstrate widening of the proximal humeral growth plate. Treatment consists of rest and avoidance of pitching for the remainder of the season. Surgery is not indicated.

Question 94

When performing a cruciate-retaining total knee arthroplasty, trial components are inserted. The knee comes to full extension but is tight in flexion. The surgeon should consider

Explanation

CLINICAL SITUATION FOR QUESTIONS 52 THROUGH 55
Figure 52 is the standing anteroposterior radiograph of a 55-year-old man who has a 5-year history of daily left knee pain with weight-bearing activities. He denies night pain or symptoms of instability. Upon examination his range of motion is 0 to 140 degrees. He has a mild, fully correctable varus deformity and a negative Lachman test result. He has failed nonsurgical treatment.

Question 95

A teenage female is referred to you for evaluation of curvature in her back that was discovered on routine school screening. She is diagnosed with adolescent idiopathic scoliosis. In which of the following scenarios is a bracing program the most appropriate treatment? Review Topic

Explanation

Bracing is most appropriate for skeletally immature patients with a curve > 20/25 degrees. Thus the patient with a left upper thoracic curve of 15 degrees and right main thoracic curve of 30 degrees in Risser stage 1 of growth meets criteria.
The treatment of adolescent idiopathic scoliosis (AIS) depends on the magnitude and location of curve as well skeletal maturity of the patient. For curves less than 20 degrees, observation is appropriate until skeletal maturity, with closer intervals during
times of peak growth. Curves between 20-25 and 45 degrees in patients who are Risser stage 0,1 or 2 are best treated with bracing to stop progression. Curves with an apex at T7 or below are typically treated with a Boston brace. Curves over 50 degrees generally warrant a discussion about surgery to prevent progression past maturity.
In a landmark study, Weinstein et al. evaluated both a randomized and preference based cohort of bracing versus observation. The trial was stopped early due to efficacy of bracing. The rate of treatment success was 72% after bracing and 48% after observation. Treatment success was strongly correlated to time of brace wear.
Schlenzka et al. reviewed indications, treatment, and complications associated with brace treatment of AIS. They state that further evidence is necessary to evaluate the efficacy of bracing in AIS.
Figure 1, 2, and 3 are radiographs depicting Risser stage 0, 1, and 4 respectively. Illustration B shows radiographs of all Risser stages. Illustration C is the Lenke classification system for idiopathic scoliosis.
Incorrect Answers:

Question 96

A 17-year-old male football player is seen 1 week after developing symptoms of infectious mononucleosis in the middle of the season. Examination reveals evidence of splenomegaly. He and his parents want to know if he can play in a game the following day. What is the most appropriate recommendation? Review Topic

Explanation

Infectious mononucleosis (IMN) is a self-limiting viral (Epstein-Barr virus) infection that affects mostly adolescents. One of the clinical findings in IMN is splenomegaly. Unfortunately, the splenomegaly is palpable only 50% of the time. The risk for spontaneous splenic rupture is highest 3 weeks after the onset of symptoms. Thus, most clinicians recommend return to contact sports after 4 weeks from the onset of symptoms. This patient presented 1 week after the onset of symptoms, so he can return to play in 3-4 weeks from the time he was examined. The athlete should be afebrile, well hydrated, and asymptomatic. Airway obstruction is usually not of concern. Disease transmission to teammates is possible in the acute phases.

Question 97

It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?

Explanation

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:

Question 98

A 65-year-old woman has nausea, vomiting, and abdominal distention after undergoing total knee arthroplasty 48 hours ago. An abdominal radiograph is shown in Figure 14. Associated risk factors for this disorder include

Explanation

DISCUSSION: The prevalence of postoperative ileus associated with total joint arthroplasty has been reported to be as high as 3%. Metabolic abnormalities such as hypokalemia are believed to contribute to the onset of ileus and Ogilvie’s syndrome (acute pseudo-obstruction of the colon). Prolonged bed rest also has been associated with the development of ileus and Ogilvie’s syndrome. Untreated Ogilvie’s syndrome can result in cecal perforation. Ileus usually is not accompanied by mechanical obstruction. Antibiotic administration and the type of anesthesia used have not been correlated with development of ileus. Administration of warfarin has been associated with elevated prothrombin time/partial thromboplastin time and international normalized ratio levels when ileus is managed with a nasogastric tube and suction. Metabolic imbalances must be corrected to reverse the ileus process.
REFERENCES: Iorio R, Healy WL, Appleby D: The association of excessive warfarin anticoagulation and postoperative ileus after total joint replacement surgery. J Arthroplasty 2000;15:220-223.
Clarke HD, Berry DJ, Larson DR: Acute pseudo-obstruction of the colon as a postoperative complication of hip arthroplasty. J Bone Joint Surg Am 1997;79:1642-1647.

Question 99

A middle-aged man sustains traumatic loss of the second, third, and fourth toes in a lawnmower accident. The wound is grossly contaminated with soil. Penicillin is added to his antibiotic regimen for coverage of what bacteria? Review Topic

Explanation

In farm or soil-contaminated wounds, including lawnmower injuries, penicillin is added to broad-spectrum cephalosporin and aminoglycoside therapy to cover against Clostridium. Psuedomonas is frequently seen after puncture wounds through the shoes. Acinetobacter is generally a hospital-acquired infection.

Question 100

Refers to the effectiveness of various antibiotics against a particular microorganism.

Explanation

DISCUSSION
Knowledge of the basic nomenclature of antibiotic use is important to effectively treat patients and communicate with colleagues. The effectiveness of an antimicrobial against an infecting organism is measured by the MIC, which refers to the concentration needed to prevent growth of a microorganism on culture medium, and MBC, which is the smallest concentration of the antibiotic necessary to kill the microorganism in culture. Typically, an antibiotic is considered bactericidal if the MBC is no more than 4 times the MIC. The spectrum of antimicrobial coverage refers to an agent’s effectiveness against a range of bacteria. An antibiogram refers to the tabulation of prevalence of different bacteria in a specific setting or specific patient population. Antibiotic susceptibility and resistance refers to the bacteria’s ability to be affected or unaffected by a given antibiotic.

Full Question & Answer Text (for Search Engines)

Question 1:

At the time of acetabular revision, retention of well-fixed femoral components inserted with first-generation cementing technique is most commonly associated with which of the following factors?

Options:

Higher subsequent loosening rate of the femoral component
Higher subsequent polyethylene wear rate
Higher subsequent dislocation rate
Higher infection rate
Unaltered subsequent survival rate of the femoral component

Correct Answer: Unaltered subsequent survival rate of the femoral component

Explanation:

Question 2:

Options:

protein C and S.
vitamin K.
von Willebrand factor.
factor VIII.

Correct Answer: factor VIII.

Explanation:

Question 3:

Options:

Biceps tenotomy
Loose body removal
Latissimus dorsi transfer
Reverse total shoulder arthroplasty

Correct Answer: Biceps tenotomy

Explanation:

Question 4:

Options:

there are no differences in functional outcome.
open diskectomy is associated with superior functional outcomes.
tubular diskectomy is associated with superior short- and long-term results.
tubular diskectomy is associated with inferior short-term results but superior long-term outcomes.

Correct Answer: there are no differences in functional outcome.

Explanation:

DISCUSSION
Several comparative studies have reported no difference in functional outcomes between tubular diskectomy and microsurgical lumbar diskectomy. A recent systematic review by Kamper and associates in which conventional microdiskectomy and minimally invasive approaches were compared revealed that there was no difference between the procedures in terms of clinical outcomes, complication risk, or rate of revision surgery.
RECOMMENDED READINGS
Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, van Tulder MW. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis. Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2. Epub 2014 Jan 18.
PubMed PMID: 24442183.
View Abstract at PubMed
Dasenbrock HH, Juraschek SP, Schultz LR, Witham TF, Sciubba DM, Wolinsky JP, Gokaslan ZL, Bydon A. The efficacy of minimally invasive discectomy compared with open discectomy: a meta-analysis of prospective randomized controlled trials. J Neurosurg Spine. 2012 May;16(5):452-62. doi: 10.3171/2012.1.SPINE11404. Epub 2012 Mar 9. PubMed PMID:

Question 5:

Figures 1 and 2 depict the postoperative radiographs obtained from a 22-year-old man who was involved in a motor vehicle accident. The most likely limitation in motion arising from this treatment is

Options:

loss of wrist flexion.
loss of wrist extension.
loss of elbow extension.
loss of pronation.

Correct Answer: loss of pronation.

Explanation:

EXPLANATION:
This patient sustained fractures of his radius and ulna; both were treated with plate and screw fixation. The plate used on the radius was straight, resulting in loss of the radial bow, which is critical for enabling the radius to curve around the ulna during pronation. This patient is unable to pronate beyond 20°. Schemitsch and Richards correlated a good functional outcome, defined as more than 80% of normal rotation of the forearm, with restoration of the normal amount and location of the radial bow. Additionally, they related the restoration of grip strength with appropriate restoration of the radial bow. Matthews and associates reported little significant loss of rotation with 10° of angulation; however, 20° of angulation
resulted in a statistically and clinically significant loss of forearm rotation.

Question 6:

Options:

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

Correct Answer: observation.

Explanation:

Question 7:

Which of the following cardiac conditions is considered an absolute contraindication to vigorous exercise?

Options:

Hypertrophic cardiomyopathy (HCM)
Sclerosis of the aortic valve without stenosis
Mild mitral valve regurgitation
Left ventricular hypertrophy (LVH)
Functional murmurs

Correct Answer: Hypertrophic cardiomyopathy (HCM)

Explanation:

Question 8:

In addition to pain, which of the following factors are considered most predictive of the risk of pathologic fracture?

Options:

Anatomic location and pattern of bony destruction
Anatomic location and age
Anatomic location and weight of patient
History of cancer and metaphyseal versus cortical destruction
Radiation dose and soft-tissue mass

Correct Answer: Anatomic location and pattern of bony destruction

Explanation:

Question 9:

Which of the following occurs frequently after nonsurgical management of displaced intra-articular fractures of the calcaneus?

Options:

Return to normal function
Narrowing of the calcaneus
Lengthening of the calcaneus
Plantar flexion of the talus
Peroneal tendinitis

Correct Answer: Peroneal tendinitis

Explanation:

Question 10:

In surgically treating hand and finger infections in patients with diabetes mellitus, what factor is associated with higher amputation rates?

Options:

Insulin dependence
Gram-positive organisms
Renal failure
Retinopathy
Peripheral neuropathy

Correct Answer: Renal failure

Explanation:

DISCUSSION: Patients with diabetes mellitus are prone to infection, and surgical treatment of their infections frequently requires multiple procedures. The triad of poor wound healing, chronic neuropathy, and vascular disease contributes to the increased infection rate. Studies have demonstrated increased amputation rates in patients with diabetes mellitus who have renal failure or deep polymicrobial or gram-negative infections.
REFERENCES: Gonzalez MH, Bochar S, Novotny J, et al: Upper extremity infections in patients with diabetes mellitus. J Hand Surg Am 1999;24:682-686.
Trumble TE (ed): Hand Surgery Update 3: Hand, Elbow, & Shoulder. Rosemont, IL, American Society for Surgery of the Hand, 2003, pp 433-457.
Kour AK, Looi KP, Phone MH, et al: Hand infections in patients with diabetes. Clin Orthop Relat Res 1996;331:238-244.

Question 11:

Arthritic change in cartilage is characterized by which of the following findings?

Options:

Proteoglycan loss in the cartilage matrix
Increased compressive modulus compared to normal cartilage
Increased tensile modulus
Decreased water content
Increase in the shear modulus

Correct Answer: Proteoglycan loss in the cartilage matrix

Explanation:

Question 12:

Options:

Selective nerve root blocks
Electromyography and a nerve conduction velocity study of the lower extremities
Ankle-brachial index (ABI)
Bilateral hip radiographs
Post-myelography CT scan

Correct Answer: Ankle-brachial index (ABI)

Explanation:

Question 13:

Integrins function in which of the following ways?

Options:

Maintain bone and cellular matrix
Form bone by producing non-mineralized matrix
Form cartilage under intermediate strain and low oxygen tension
Attachment of osteoclasts to bone surfaces
Binds to RANKL on the osteoblast, preventing RANK activation

Correct Answer: Binds to RANKL on the osteoblast, preventing RANK activation

Explanation:

Question 14:

A child with an idiopathic clubfoot is successfully treated by the Ponseti method. The risk of recurrence of the deformity is most dependent on which of the following factors? Review Topic

Options:

Maternal age
Positive family history
Family's compliance with bracing
The child's age at walking
The child's body mass index

Correct Answer: Family's compliance with bracing

Explanation:

Question 15:

A patient with Paget disease who is intolerant of bisphosphonates is given calcitonin. What is the mechanism of action of calcitonin?

Options:

Promotes reabsorption of phosphate in the renal tubules
Interferes with osteoclast maturation
Interferes with intestinal absorption of calcium
Upregulates osteoblast formation

Correct Answer: Interferes with osteoclast maturation

Explanation:

Question 16:

Options:

bunion repair only.
bunionette repair only with lateral condylectomy.
repair of both with lateral condylectomy.
repair of both with a proximal fifth metatarsal osteotomy.
repair of both with a fifth metatarsal head excision.

Correct Answer: repair of both with lateral condylectomy.

Explanation:

Question 17:

Options:

Physical therapy with electrical stimulation and iontophoresis
Corticosteroid injection
MRI of the shoulder
Electromyography (EMG) of the arm

Correct Answer: MRI of the shoulder

Explanation:

Question 18:

Options:

- Nail radius of curvature
- Osteoarthrosis
- Nonunion of fracture
- Improper starting point for nail

Correct Answer: - Nail radius of curvature

Explanation:

DISCUSSION
Three cases of anterior distal femoral cortex penetration during intramedullary nailing for subtrochanteric fractures were documented by Ostrum and Levy in a 2005 study. Case 1 involved a Zimmer (Warsaw, Indiana) M/DN antegrade femoral nail, Case 2 involved a Stryker (Mahwah, New Jersey) long-stem Gamma nail, and Case 3 a DePuy Synthes (West Chester, Pennsylvania) titanium femoral nail with spiral blade locking. The anterior Zimmer nail penetration resulted in a displaced supracondylar fracture, which subsequently required revision. The Gamma nail as well as the DePuy Synthes nail were left impaled through the distal femoral cortex, and the subtrochanteric fractures went on to union. The anteroposterior radius of curvature for the Zimmer, long Gamma, and DePuy Synthes nails is 257 cm, 300 cm, and 150 cm, respectively. It is estimated that the radius of curvature of the femoral diaphyseal canal is 114 to 120 cm. It appears that the difference in femoral anteroposterior bow between the bone and the implant is a contributing factor to distal femoral anterior cortex penetration in intramedullary nailing of subtrochanteric fractures. There is no evidence of osteoarthrosis on the radiographs. Although nonunion is possible, based on the radiographic findings it is more likely that this patient's pain is attributable to the curvature of the nail. The lateral image of the hip reveals an appropriate starting point for the device.
RECOMMENDED READINGS
Ostrum RF, Levy MS. Penetration of the distal femoral anterior cortex during intramedullary nailing for subtrochanteric fractures: a report of three cases. J Orthop Trauma. 2005 Oct;19(9):656-60. PubMed PMID: 16247312.
View Abstract at PubMed
Egol KA, Chang EY, Cvitkovic J, Kummer FJ, Koval KJ. Mismatch of current intramedullary nails with the anterior bow of the femur. J Orthop Trauma. 2004 Aug;18(7):410-5. PubMed PMID: 15289685.
View Abstract at PubMed
RESPONSES FOR QUESTIONS 76 THROUGH 78
- Nonsurgical treatment with closed reduction and immobilization
- Early mobilization with physical therapy initiated within 2 weeks
- Open reduction and internal fixation (ORIF) with locked implants
- Use of supplemental bone graft or substitutes
- Arthroplasty
- Workup for osteoporosis and counseling
Which intervention listed is most appropriate to address each scenario described?
76A B

Question 19:

Options:

Preliminary skin traction followed by closed reduction under general anesthesia
Immediate closed reduction under anesthesia
Preliminary skeletal traction followed by closed reduction under general anesthesia
Bilateral open reduction performed through a medial approach
Bilateral open reduction performed through an anterior approach

Correct Answer: Bilateral open reduction performed through a medial approach

Explanation:

Question 20:

Options:

Allow him to continue playing football
Order an EMG
Observe and if symptoms are negative for one week, then a return to football
Order a cervical MRI scan

Correct Answer: Order a cervical MRI scan

Explanation:

Question 21:

- Figures 37a & 37b show radiographs of a right handed, 78 year old man who had painful G-H arthritis, moderate limitation of motion, and good strength prior to replacement of the humeral head 2 years ago. At the time of treatment, the rotator cuff was intact. He now has limited motion, weakness, and persistent pain in the shoulder. What is the most likely diagnosis?

Options:

Infection
Tear of the rotator cuff
Loosening of the humeral component
Arthritis of the glenoid
Arthritis of the A-C joint

Correct Answer: Arthritis of the glenoid

Explanation:

Question 22:

Options:

Plastizote orthotics with a metatarsal pad and a cutout under the fifth metatarsal head
Hyperbaric oxygen and prolonged non-weight-bearing
A healing shoe that completely alleviates any weight bearing on the forefoot
A gastrocnemius release and supportive wound care
A transmetatarsal amputation

Correct Answer: A gastrocnemius release and supportive wound care

Explanation:

DISCUSSION: The patient likely has a significant Achilles contracture that causes her to always bear more weight on her forefoot. A gastrocnemius recession takes the ankle out of plantar flexion and she will be able to return to a normal gait and reduce the pressures on her forefoot. A forefoot amputation is a salvage option. The other choices are appropriate; however, the patient has had this problem for 2 years and she has already had multiple attempts at shoe wear modification.
REFERENCES: Laughlin RT, Calhoun JH, Mader JT: The diabetic foot. J Am Acad Orthop Surg 1995;3:218-225.
Aronow MS, Diaz-Doran V, Sullivan RJ, et al: The effect of triceps surae contracture force on plantar foot pressure distribution. Foot Ankle Int 2006;27:43-52.

Question 23:

Options:

Weakness of hip flexion
Weakness of ankle dorsiflexion
Numbness of the medial thigh
Numbness of the lateral thigh
Numbness of the perineum

Correct Answer: Weakness of hip flexion

Explanation:

Question 24:

Options:

Physical therapy
CT-guided needle biopsy and IV antibiotics
Revision laminotomy and diskectomy
L4-L5 anterior debridement and fusion
Open repair of the L4-L5 pseudomeningocele

Correct Answer: Physical therapy

Explanation:

The MRI scans show Modic changes in the L4-L5 vertebral bodies due to spondylosis. There is no increased fluid signal or enhancement in the L4-L5 disk to suggest infection or any other pathologic process. Therefore, the patient’s pain should be treated with a course of physical therapy and rehabilitation. There is no infection; therefore, IV antibiotics and debridement are not indicated. Similarly, a
pseudomeningocele is not present. A revision diskectomy is useful for recurrent radiculopathy but would not be helpful for degenerative low back pain.
(SBQ12SP.29) A 17-year-old female is undergoing posterior instrumented fusion from T5-T12 for adolescent idiopathic scoliosis. At the time of the correction maneuver, the neurophysiologist notifies you of a 60% decrease in somatosensory evoked potential (SSEP) amplitude throughout bilateral lower extremities. Which of the following is an acceptable approach to manage this finding?
Review Topic
Immediate wake-up test with examination for clonus
Drop the mean arterial pressure (MAP) to ~60mmHg
Discontinue instrumentation and optimize MAP to 85mmHg or greater
Immediate infusion of intravenous corticosteroids
Modification of the anesthesia plan to include inhalational agents only followed by repeated SSEP testing
The patient has a significant drop in SSEP amplitudes at the completion of the corrective maneuver. The most appropriate response is to raise the MAP to 85 mmHg or greater, discontinue the instrumentation, re-evaluate the SSEPs, and if there is no improvement, to consider reversing the reduction of the deformity.
Intra-operative neurophysiologic monitoring is an effective method to monitor insults to the spinal cord and its exiting roots during spinal instrumentation. The common measurements include SSEPs, which monitor sensory potentials transmitted through the dorsal column system, and motor-evoked potentials (MEPs), which monitor motor response to a trans-cranial stimulus. Decreases in amplitude and latency of the circuits are recorded, however diminished signal amplitudes are more sensitive for neurologic injury, and decreases of of >50-60% being highly concerning. The wake-up test involves reversal of anesthesia so that an intra-operative neurologic examination can be performed.
Devlin et al. reviewed the basic science and practice of neurophysiologic monitoring in spine surgery. They proposed an algorithmic approach to managing intraoperative alerts which include discontinuation of inhalational anesthetics, increasing the MAP to >90 mmHg, discontinuing instrumentation, and performing a wake-up test if neurologic signals fail to normalize.
Herdmann et al. reviewed the practice of neurophysiologic monitoring and the effects of anesthesia upon signal transduction. They report that anesthesia affecting a neuron's intrinsic excitability can alter the results of monitoring. Inhalational anesthetics and decreased MAPs can be responsible for decreased amplitudes.
Vitale et. al. developed a consensus-based intraoperative checklist for management of lost neuromonitoring signals. In this checklist, the first steps across the surgical and anesthetic teams should include: stop the case and announce signal losses to the room, optimize the mean arterial pressure, discuss the status of anesthetic agents, and discuss reversible surgical actions just prior to signal loss.
Incorrect

Question 25:

Which of the following is helpful on physical examination to diagnose a fixed posterior shoulder dislocation? Review Topic

Options:

Apprehension sign
Jobe relocation test
Sulcus sign
Jerk test
Lack of external rotation

Correct Answer: Lack of external rotation

Explanation:

Question 26:

Options:

Initiate isometric external rotation strengthening and continue passive range of motion.
Initiate eccentric supraspinatus strengthening and continue passive range of motion.
Initiate light resistance training to minimize atrophy and continue passive range of motion.
Continue passive range of motion and initiate concentric deltoid strengthening.
Continue passive range of motion with no active strengthening of the shoulder muscles.

Correct Answer: Continue passive range of motion with no active strengthening of the shoulder muscles.

Explanation:

Question 27:

Which of the following illustrations shown in Figures 21a through 21e correctly shows the projection of the sacroiliac joint on the outer table of the ilium?

Options:

Correct Answer: 21c

Explanation:

Question 28:

The usual presentation of traumatic subscapularis tears is most often seen after forced

Options:

internal rotation.
external rotation.
extension.
abduction.
forward flexion.

Correct Answer: external rotation.

Explanation:

DISCUSSION: The typical mechanism of injury is a fall and the patient grasps something to prevent the fall. This maneuver forces the arm into external rotation against resistance.
REFERENCES: Kreuz PC, Remiger A, Erggelet C, et al: Isolated and combined tears of the subscapularis tendon. Am J Sports Med 2005;33:1831-1837.
Gerber C, Hersche O, Farron A: Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-1023.

Question 29:

During anterior surgery on the cervical spine, at what level would the lateral dissection of the longus coli muscle most likely cause Horner’s syndrome?

Options:

Correct Answer: C6

Explanation:

Question 30:

What is the most common complication of using structural bulk allograft to reconstruct segmental defects of the acetabulum?

Options:

Infection
Early loss of cup fixation
Graft resorption and collapse
Limb-length discrepancy
Dislocation

Correct Answer: Graft resorption and collapse

Explanation:

Question 31:

Options:

Gender
Age
Sport
Bone loss DISCUSSION… Nonsurgical treatment for a first-time traumatic dislocation may not be effective in a young, athletic patient; moreover, a Bankart lesion may be present in 70% of all traumatic subluxations. A period of immobilization in external rotation may decrease the risk for recurrence, but only if the patient is placed in a brace immediately and complies with the treatment. Return to play may be possible after 2 weeks of immobilization, provided the patient undergoes appropriate range of motion, cuff strengthening, and scapular stabilization exercises. Among athletes in 1 study, 80% were able to finish the season, but 40% experienced episodes of subluxation or recurrent dislocation prior to the end of the season. The rate of recurrence after arthroscopic stabilization should be lower than 10% and may be equivalent to open repair for most patients. Bone loss remains the primary indication for open procedures, as coracoid transfers or other bone-grafting operations may be needed to reconstruct the glenoid if more than 20% of its surface area is missing. Furthermore, collision athletes may fare better with open surgery than arthroscopic options. Bone loss remains the most significant factor for recurrence across many studies. Glenoid bone loss may be present in 20% of primary dislocations and 70% of recurrent dislocations. Age younger than 30 has a high correlation with recurrence. Although men may be almost twice as likely as women to have a recurrent dislocation, age seems to be the most reliable patient-related risk factor for recurrence. Thermal capsulorrhaphy has not proven to be effective and carries a high risk for complication. More recent studies have found equal recurrence rates between open and arthroscopic Bankart repair, with a greater loss of motion in patients who underwent open repair. Longitudinal studies have demonstrated that 40% to 50% are likely to develop arthritis after a shoulder dislocation; however, recurrent dislocation seems to be the most important factor for early development of arthritis, while age younger than 25 may be protective. Postcapsulorrhaphy arthropathy may be more associated with open repairs or those that severely limit external rotation.

Correct Answer: Age

Question 32:

Options:

Shingles
Cellulitis
Charcot foot
Osteomyelitis
Reflex sympathetic dystrophy

Correct Answer: Reflex sympathetic dystrophy

Explanation:

Question 33:

Based on the findings seen in the radiograph in Figure 26, emergent management should consist of

Options:

volar open reduction and pinning.
open reduction, ligament repair, and pinning.
closed reduction and splinting.
closed reduction and pinning.
dorsal open reduction and pinning.

Correct Answer: closed reduction and splinting.

Explanation:

Question 34:

Options:

Use a larger femoral component
Use a thinner polyethylene insert
Add posterior femoral augments
Resect more proximal tibia
Resect additional distal femur

Correct Answer: Resect additional distal femur

Explanation:

DISCUSSION: The reconstruction requires additional resection of the distal femur to allow increased extension while maintaining the current flexion gap tension. Resecting more proximal tibia or decreasing the tibial polyethylene thickness will decrease flexion tension as well as extension tension. Adding posterior femoral augments and using a larger femoral component will increase flexion tension.
REFERENCES: Ayers DC, Dennis DA, Johanson NA, et al: Common complications of total knee arthroplasty. J Bone Joint Surg Am 1997;79:278-311.
Pelicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 281-286.

Question 35:

This medication, a factor Xa inhibitor, currently is not approved for venous thromboembolism (VTE) prophylaxis.

Options:

- Warfarin (Coumadin)
- Dabigatran (Pradaxa)
- Rivaroxaban (Xarelto)
- Apixaban (Eliquis)

Correct Answer: - Apixaban (Eliquis)

Explanation:

DISCUSSION
Warfarin has a long clinical track record and is well known among most physicians. It is a vitamin K antagonist that can be monitored with prothrombin time (INR) testing and reversed with vitamin K and fresh frozen plasma if needed. Newer oral anticoagulants are becoming more common and offer the advantage of being rapidly active without a need for monitoring. These oral anticoagulants are not reversible, which can complicate the treatment of patients who present with bleeding or require surgery. Dabigatran (Pradaxa) is a direct thrombin inhibitor that is approved for stroke prevention in atrial fibrillation. It is not reversible, and a surgical delay of 24 to 48 hours is recommended for all but emergent surgeries. A longer delay is recommended with renal insufficiency. Rivaroxaban (Xarelto) is an oral factor Xa inhibitor that is approved for atrial fibrillation and the treatment of VTE and deep vein thrombosis prophylaxis. It offers the advantage of daily dosing. It
is not reversible and a surgical delay of 36 to 48 hours is recommended. Apixaban (Eliquis) is another factor Xa inhibitor for which twice-daily dosing is required. It is currently approved for stroke prevention in atrial fibrillation, and a surgical delay of 36 to 48 hours is recommended.
RECOMMENDED READINGS
Gonsalves WI, Pruthi RK, Patnaik MM. The new oral anticoagulants in clinical practice. Mayo Clin Proc. 2013 May;88(5):495-511. doi: 10.1016/j.mayocp.2013.03.006. Review. Erratum in: Mayo Clin Proc. 2013 Jul;88(7):777. PubMed PMID: 23639500.
View Abstract at PubMed
Alquwaizani M, Buckley L, Adams C, Fanikos J. Anticoagulants: A Review of the Pharmacology, Dosing, and Complications. Curr Emerg Hosp Med Rep. 2013 Apr 21;1(2):83-97. Print 2013 Jun. PubMed PMID: 23687625.
View Abstract at
PubMed
CLINICAL SITUATION FOR QUESTIONS 100 AND 101
A 55-year-old woman slipped on ice while getting out of her car and sustained the injury shown in Figure 100.

Question 36:

Which of the following conditions precludes performing a tendon transfer?

Options:

The target joint has a full passive range of motion.
The range of motion of the target joint only occurs in the direction of correction.
The target joint cannot be passively corrected to its neutral position.
The muscle to be transferred is out-of-phase.
There is no pulley to assist the transferred muscle’s fulcrum.

Correct Answer: The target joint cannot be passively corrected to its neutral position.

Explanation:

DISCUSSION: Several conditions must be met before a tendon transfer has the potential to correct a dynamic deformity. If the target joint cannot be passively corrected to neutral, it indicates that a static joint contracture or bony deformity exists that cannot be corrected with a dynamic tendon transfer. While in-phase muscles are best, out-of-phase muscles are often the only muscles available for transfer. Tendon transfer should pull in a straight line to avoid tethering and late failure.
REFERENCES: Canale ST (ed): Campbell’s Operative Orthopaedics, ed 10. St Louis, MO, Mosby, 2003, pp 1283-1287.
Coughlin MJ, Mann RA: Disorders of tendons, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 7. St Louis, MO, Mosby, 1999, pp 786-861.

Question 37:

Options:

Hanging arm cast
Closed reduction with flexible intramedullary nail fixation
Coaptation splinting and bandaging the arm to the thorax
Closed reduction and external fixation
Locking plate fixation

Correct Answer: Coaptation splinting and bandaging the arm to the thorax

Explanation:

Question 38:

Options:

resection of the coalition with fat graft interposition.
Grice extra-articular subtalar arthrodesis.
subtalar arthroereisis.
intra-articular subtalar fusion.
medial sliding calcaneal osteotomy.

Correct Answer: resection of the coalition with fat graft interposition.

Explanation:

DISCUSSION: The CT scan is an important test to help determine the extent of involvement of the talocalcaneal facet in a talocalcaneal coalition. In a young patient with no arthritis and joint involvement of less than 50%, resection of the coalition and fat pad interposition has been shown to be successful. A calcaneal osteotomy does not address the coalition. Subtalar arthroereisis has been used for treatment of a flexible flatfoot; tarsal coalition patients have a rigid-type flatfoot deformity.
REFERENCES: Sullivan JA: The child’s foot, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1077-1135.
Scranton
PE
Jr: Treatment of symptomatic talocalcaneal coalition. J Bone Joint Surg Am 1987;69:533-539.

Question 39:

Options:

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

Correct Answer: Patellofemoral syndrome

Explanation:

Question 40:

Options:

Will result in improvement in pain but no difference in function or range of motion compared to therapy alone.
Will result in greater improvement in pain and function compared to therapy alone, with equivalent range of motion at one year
Will prevent development of rotator cuff arthropathy in patients with rotator cuff tears.
Will likely have no effect on pain, function or range of motion at one year, compared to therapy alone.
Will result in worse outcomes in terms of pain, function and range of motion, compared with therapy alone.

Correct Answer: Will result in worse outcomes in terms of pain, function and range of motion, compared with therapy alone.

Explanation:

Question 41:

- What is the most common nerve injury following a Monteggia fracture-dislocation of the forearm in adults?

Options:

Posterior interosseous
Anterior interosseous
Radial
Median
Ulnar

Correct Answer: Posterior interosseous

Explanation:

According to Rockwood and Green the most commonly injured nerve associated with a Monteggia fracture is the posterior interosseous nerve, a branch of the radial nerve.

Question 42:

Up to what time frame are the risks minimized in anterior revision disk replacement surgery? Review Topic

Options:

3 days
1 week
10 days
2 weeks
6 weeks

Correct Answer: 2 weeks

Explanation:

Question 43:

Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

Options:

Lower cervical spine
Midthoracic spine
Thoracolumbar junction
Midlumbar spine
Lumbosacral junction

Correct Answer: Midlumbar spine

Explanation:

Question 44:

A 17-year-old girl has multidirectional instability of the shoulder. What is the most appropriate initial management? Review Topic

Options:

Immobilization in a sling and swathe
Open capsular shift
Arthroscopic capsular plication
Thermal capsulorrhaphy
Physical therapy and home exercises

Correct Answer: Physical therapy and home exercises

Explanation:

Question 45:

Early postoperative infections following primary total hip arthroplasty are most likely caused by which organism?

Options:

Staphylococcus epidermidis
Streptococcus viridans
Propionibacterium acnes
Staphylococcus aureus

Correct Answer: Staphylococcus aureus

Explanation:

DISCUSSION:
S aureus
is the most common organism cultured in early (fewer than 4 weeks postoperative) periprosthetic infections. Methicillin-resistant
S aureus
is becoming a more common pathogen in certain patient populations. B hemolytic
Streptococcus
and some gram-negative infections can also be found in early postoperative infections.
S epidermidis
,
S viridans
, and
P acnes
are more commonly found in late (more
than 4 weeks postoperative) infections.

Question 46:

Options:

Osteogenic sarcoma
Ewing’s sarcoma
Giant cell tumor of bone
Aneurysmal bone cyst
Metastatic adenocarcinoma

Correct Answer: Giant cell tumor of bone

Explanation:

Question 47:

- A consecutive series of 50 patients is randomized to receive either treatment A or treatment B. At a 10-year follow up, patient satisfaction with treatment is measured. Which of the following statistical calculations will provide the most information regarding the magnitude of possible differences between the two groups of patients?

Options:

Meta-analysis
Confidence interval
Analysis of variance (ANOVA)
Statistical significance (p-value)
Survivorship analysis (Kaplan-Meier)

Correct Answer: Confidence interval

Explanation:

Question 48:

Options:

open reduction internal fixation of the fibula only
open reduction internal fixation of the tibia and fibula
removal of external fixator and conversion to a walking cast
dynamization of the external fixator
tibio-talar arthrodesis

Correct Answer: open reduction internal fixation of the tibia and fibula

Explanation:

Question 49:

Options:

Observation
Oral antibiotics for 6 weeks
IV antibiotics for 6 weeks
Arthroscopic irrigation and debridement with graft retention
Arthroscopic irrigation and debridement with graft removal

Correct Answer: Observation

Explanation:

Question 50:

Options:

C-reactive protein (CRP)
Synovial fluid analysis of affected joints
Blood cultures
Cervical radiographs
Bethesda assay

Correct Answer: Bethesda assay

Explanation:

Question 51:

Options:

Infection
Osteosarcoma
Osteoblastoma
Giant cell tumor
Distal femoral fracture

Correct Answer: Osteosarcoma

Explanation:

Question 52:

Options:

Observation and NSAID use as needed
MRI scan
Bone biopsy
Serum protein electrophoresis (SPEP) and urine protein electrophoresis (UPEP).

Correct Answer: Observation and NSAID use as needed

Explanation:

DISCUSSION
The radiograph shown is consistent with Paget disease of the bone. It demonstrates classic findings of widened lamellae and disorganized sclerotic and lytic areas. The cause is not clearly defined, but may be linked to a viral infection and subsequent alterations of osteoblastic and osteoclastic activity. Most patients are asymptomatic, and Paget disease is often found incidentally on radiographs. In this case, the patient’s symptoms likely were caused by hip arthritis, but Paget disease can cause diffuse bone pain in some cases. Considering the patient’s mild and short-term symptoms, observation and NSAID use is most appropriate. An MRI scan or biopsy is indicated if sarcomatous transformation is suspected, but this condition is rare and is associated with a substantial, unrelenting increase in pain. SPEP and UPEP are tests for multiple myeloma, of which the radiographs show no signs.
RECOMMENDED READINGS
Ralston SH. Pathogenesis of Paget's disease of bone. Bone. 2008 Nov;43(5):819-25. doi: 10.1016/j.bone.2008.06.015. Epub 2008 Jul 11. Review. PubMed PMID: 18672105.
View Abstract at PubMed
Bonenberger E, Einhorn T. Metabolic bone diseases. In: Callaghan JJ, Rosenberg
AG, Rubash HE, eds. The Adult Hip. 2nd ed. Philadelphia, PA: Lippincott Williams
14
& Wilkins; 2007:514-533.

Question 53:

Options:

MRI
Arthrocentesis for synovial fluid cell count and bacterial culture
Ophthalmology consultation
Angiotensin converting enzyme (ACE) level
Technetium radioisotope bone scan

Correct Answer: Ophthalmology consultation

Explanation:

DISCUSSION: Up to 30% of children with juvenile rheumatoid arthritis (increasingly known now as juvenile idiopathic arthritis or JIA) already have potentially damaging uveitis at the time of diagnosis. This patient has typical oligoarticular JRA (JIA) and therefore is at significant risk for uveitis. MRI, radioisotope scanning, or an ACE level most likely would not provide additional useful diagnostic information because intra-articular derangement, osteomyelitis, or sarcoidosis are all unlikely. Arthrocentesis and triamcinolone hexacetonide joint injection might be indicated if continued use of nonsteroidal medication does not result in improvement, but should be held off for at least an additional 4 to 6 weeks to see if continued use of naproxen results in control of the arthritis.
REFERENCES: Wolf MD, Lichter PR, Ragsdale CG: Prognostic factors in the uveitis of juvenile rheumatoid arthritis. Ophthalmology 1987;94:1242.
Cassidy JT, Petty RE: Textbook of Pediatric Rheumatology. Philadelphia, PA, WB Saunders, 2001, p 220.
Chalom ED, Goldsmith DP, Koehler MA, et al: Prevalence and outcome of uveitis in a regional cohort of patients with juvenile rheumatoid arthritis. J Rheumatol 1997;24:2031-2034.

Question 54:

What is the most common primary malignant tumor of bone in childhood?

Options:

Periosteal chondroma
Ewing’s sarcoma
Osteosarcoma
Chondrosarcoma
Rhabdomyosarcoma

Correct Answer: Osteosarcoma

Explanation:

Question 55:

Options:

removal of the halo vest, followed by observation if the patient remains asymptomatic.
use of the halo vest for an additional 4 weeks, followed by repeat radiographs.
placement of one odontoid screw and the addition of bone graft.
placement of two odontoid screws.
posterior fusion at C1-2.

Correct Answer: posterior fusion at C1-2.

Explanation:

Question 56:

Options:

MRI of the affected tibia
Palpation of the affected leg compartments during activity
Compartment pressure monitoring 1 and 5 minutes into the activity
Compartment pressure monitoring continuously during the activity

Correct Answer: Compartment pressure monitoring continuously during the activity

Explanation:

Question 57:

Options:

Neutral posted rigid custom foot orthosis
Custom rigid UCBL foot orthosis
Ankle-foot orthosis with the ankle locked at 90 degrees
Shoe modification with a cushioned heel and rocker sole
Metal hinged/leather short ankle “Arizona” orthosis

Correct Answer: Shoe modification with a cushioned heel and rocker sole

Explanation:

DISCUSSION: The patient has a malunion of an attempted open reduction of a Lisfranc dislocation. The pain occurs during the terminal stance phase of gait as load is being transferred from the hindfoot to the forefoot. The bending moment can be best neutralized with shoe modification with a cushioned heel and rocker sole, which best unloads the tarsal-metatarsal junction.
REFERENCES: Bono CM, Berberian WS: Orthotic devices: Degenerative disorders of the foot and ankle. Foot Ankle Clin 2001;6:329-340.
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 58-63.

Question 58:

Options:

A 45-year-old woman with a hypermobile foot
A 45-year-old man with a rigid hindfoot valgus deformity
A thin 55-year-old woman with mild hemiparesis affecting the symptomatic foot from a previous stroke
An active 55-year-old woman with a progressively worsening supple hindfoot valgus
A moderately obese 70-year-old woman with a supple hindfoot

Correct Answer: An active 55-year-old woman with a progressively worsening supple hindfoot valgus

Explanation:

Question 59:

Options:

Injury to the anterior band of the medial collateral ligament
Injury to the radial nerve
Injury to the lateral ulnar collateral ligament
Injury to the lateral radial collateral ligament
Excessive dissection of the extensor carpi radialis brevis origin

Correct Answer: Injury to the lateral ulnar collateral ligament

Explanation:

Question 60:

Avascular necrosis

Options:

Slipped epiphysis
This patient has a subtle grade 1 slipped capital femoral epiphysis. He is a male Risser 0 and is overweight. He has decreased internal rotation of the involved hip in flexion. The plain pelvis radiograph shows slightly less epiphyseal height on the left side, slight posterior metaphyseal overlap, and increased irregularity of the physis. MRI confirms a lucent plane in the physis and surrounding edema. A plain film (Slide 3) confirms the diagnosis. In situ fixation was performed on this patient.

Correct Answer: Slipped epiphysis

Explanation:

Slide
A 9-year-old girl sustains an injury (Slide) as a result of a fall. What is her risk of avascular necrosis:

Question 61:

The safest surgical approach to the insertion of the tibial posterior cruciate ligament uses the interval between which of the following muscles?

Options:

Semimembranosus and medial gastrocnemius
Semimembranosus and semitendinosus
Medial and lateral gastrocnemius
Lateral gastrocnemius and biceps femoris tendon
Popliteus and lateral gastrocnemius

Correct Answer: Semimembranosus and medial gastrocnemius

Explanation:

DISCUSSION: Burks and Schaffer described an approach to the tibial insertion of the posterior cruciate ligament that uses the interval between the semimembranosus and the medial gastrocnemius. The medial gastrocnemius muscle is retracted laterally and protects the neurovascular bundle. This approach is used to repair an avulsion of the posterior cruciate ligament tibial attachment or for performing a posterior cruciate ligament tibial
inlay reconstruction.
REFERENCES: Berg EE: Posterior cruciate ligament tibial inlay reconstruction. Arthroscopy 1995;8:95-99.
Burks RT, Schaffer JJ: A simplified approach to the tibial attachment of the posterior cruciate ligament. Clin Orthop 1990;254:216-219.

Question 62:

Options:

Biotin.
Tramadol.
vitamin A.
vitamin C.
vitamin E.

Correct Answer: vitamin C.

Question 63:

A 14-year-old girl reports hip pain that is exacerbated by weight bearing. A radiograph and biopsy specimen are shown in Figures 16a and 16b. The best course of management should be

Options:

a steroid injection.
curettage and bone grafting.
radiation therapy.
observation.
internal fixation without a bone graft.

Correct Answer: curettage and bone grafting.

Explanation:

Question 64:

What role does quorum sensing play in the development of a bacterial biofilm?

Options:

Activates genes that produce virulence factors
Creates planktonic bacteria
Facilitates bacterial adhesion to a substrate
Lowers antimicrobial resistance

Correct Answer: Activates genes that produce virulence factors

Explanation:

Question 65:

The Chi-square test is most appropriate for which of the following?

Options:

Comparing means of parametric numeric data between two groups
Comparing means of non-parametric numeric data between two groups
Comparing means of parametric numeric data between 3 or more groups
Comparing categorical data between groups
Comparing categorical data between groups with less than 5 samples or data points per group

Correct Answer: Comparing means of parametric numeric data between two groups

Explanation:

Question 66:

Within the menisci, the majority of the large collagen fiber bundles are oriented in what configuration?

Options:

Radially
Circumferentially
Vertically
Obliquely
Randomly

Correct Answer: Circumferentially

Explanation:

Question 67:

Options:

High parathyroid hormone, normal calcium, normal alkaline phosphatase, low phosphorus, low vitamin D
High parathyroid hormone, low calcium, high alkaline phosphatase, low phosphorus, low vitamin D
Normal parathyroid hormone, high calcium, low alkaline phosphatase, low phosphorus, low vitamin D
Low parathyroid hormone, normal calcium, normal alkaline phosphatase, low phosphorus, low vitamin D
Low parathyroid hormone, low calcium, high alkaline phosphatase, low phosphorus, low vitamin D

Correct Answer: High parathyroid hormone, normal calcium, normal alkaline phosphatase, low phosphorus, low vitamin D

Explanation:

Question 68:

The great medullary artery, also known as the Adamkiewicz artery, originates from which of the following arteries?

Options:

Left posterior intercostal between T8 and T12
Posterior spinal between T1 and T12
Anterior spinal between T4 and T6
Superior phrenic
Inferior phrenic

Correct Answer: Left posterior intercostal between T8 and T12

Explanation:

Question 69:

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

Options:

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

Correct Answer: extended curettage.

Explanation:

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

Question 70:

Options:

Hemiarthroplasty
Arthroscopic debridement
Total shoulder arthroplasty with a cemented all-polyethelene glenoid component
Reverse total shoulder arthroplasty
Total shoulder arthroplasty with a metal-backed glenoid component

Correct Answer: Total shoulder arthroplasty with a cemented all-polyethelene glenoid component

Explanation:

Question 71:

Options:

Cast removal and measurement of carpal canal pressure
Immediate carpal tunnel release and pinning of the fracture
Continued observation
Surgical reduction and pinning of the fracture
Electromyography/nerve conduction velocity studies

Correct Answer: Immediate carpal tunnel release and pinning of the fracture

Explanation:

DISCUSSION: The patient has an evolving acute carpal tunnel syndrome. Initial management for this injury is to relieve all external pressure that may elevate the neural compression. Surgical decompression of the median nerve at the carpal tunnel is the optimal intervention. Further nonsurgical interventions (cast removal or further bivalving) are insufficient to alleviate the neural compression.
REFERENCES: Waters PM, Mih AD: Fractures of the distal radius and ulna, in Beaty JH, Kasser JR (eds): Fractures in Children, ed 6. Philadelphia, PA, Lippincott, 2006, p 361.
Paley D, McMurtry RY: Median nerve compression by volarly displaced fragments of the distal radius. Clin Orthop Relat Res 1987;215:139-147.

Question 72:

Options:

Quicker time to union
Decreased risk of malunion
Decreased risk of compartment syndrome
Decreased risk of shortening
Quicker return to work

Correct Answer: Quicker time to union

Explanation:

Question 73:

Options:

Hard cervical orthosis
Immobilization in cervico-thoraco-lumbo-sacral orthosis
Anterior decompression and fusion of C4-C7
Posterior decompression and fusion of C5-C6
Posterior decompression and fusion of C3-T2

Correct Answer: Hard cervical orthosis

Explanation:

Question 74:

Options:

Open tibial apophysis
Medial patellar cartilage defect
Femoral trochlear sulcus angle = 165°
Tibial tubercle-trochlear groove distance = 25mm
Patella tilt = 25°

Correct Answer: Open tibial apophysis

Explanation:

Question 75:

Options:

a hard cervical collar for 6 weeks.
skeletal traction for 6 weeks, followed by halo vest immobilization for 6 weeks.
halo vest immobilization for 3 months.
posterior cervical C1-2 wiring with arthrodesis.
anterior C2-3 diskectomy, fusion, and plating.

Correct Answer: posterior cervical C1-2 wiring with arthrodesis.

Explanation:

DISCUSSION: The lateral radiograph shows 8 mm of atlantoaxial translation. In the absence of a bony injury, this represents rupture of the transverse atlantal ligament. The MRI scan reveals soft-tissue swelling posterior to the odontoid and a high intensity zone in the atlanto-dens interval consistent with acute injury. These injuries require arthrodesis because nonsurgical measures will not provide stability. Techniques for C1-2 fusion include Gallie, Brooks, or triple wiring. Transarticular screw fixation across the C1-2 articulation provides the most rigid means of fixation and the highest arthrodesis rates but is technically demanding. Anterior C2-3 arthrodesis will not address the level of instability. The normal atlanto-dens interval is 3 mm in an adult and 4 mm in a child.
REFERENCES: Kurz LT: Transverse atlantal ligament insufficiency, in Clark CR (ed):
The Cervical Spine. Philadelphia, PA, Lippincott-Raven, 1998, pp 401-407.
Fielding JW, Cochran GB, Lansing JF III, et al: Tears of the transverse ligament of the atlas:
A clinical and biomechanical study. J Bone Joint Surg Am 1974;56:1683-1691.

Question 76:

An adult with a distal humeral fracture underwent open reduction and internal fixation. What is the most common postoperative complication?

Options:

Loss of elbow range of motion
Nonunion
Malunion
Infection
Ulnar nerve dysfunction

Correct Answer: Loss of elbow range of motion

Explanation:

Question 77:

What structure is marked Q in the diagram of the brachial plexus shown in Figure 22?

Options:

Medial cord
Lateral cord
Posterior cord
Upper trunk
Lower trunk

Correct Answer: Posterior cord

Explanation:

Question 78:

Options:

Inflation of the abdominal portion of the PASG
Application of a pelvic clamp
Application of a pelvic external fixator
Rapid infusion of 4 more units of blood
Angiography and embolization

Correct Answer: Angiography and embolization

Explanation:

Question 79:

Options:

Osteomyelitis
Lymphoma
Myeloma
Ewing’s sarcoma
Osteosarcoma

Correct Answer: Myeloma

Explanation:

Question 80:

Following a partial muscle laceration, keeping the affected extremity immobilized for 2 weeks before starting an exercise program will likely lead to: Review Topic

Options:

Greater area of fibrous scar tissue than immediate mobilization
Less fatty infiltration than immediate mobilization
Atrophy limiting final functional outcome
Better penetration of ingrowing muscle fibers than a shorter period of immobilization
More uniform orientation of ingrowing muscle fibers than a shorter period of immobilization

Correct Answer: Better penetration of ingrowing muscle fibers than a shorter period of immobilization

Explanation:

Question 81:

What is the most common reason for reoperation in total knee arthroplasty?

Options:

Polyethylene insert failure
Malalignment of the knee
Ligamentous instability
Perioperative infection
Patellar-related complications

Correct Answer: Patellar-related complications

Explanation:

Question 82:

Figures 45a through 45c show the radiograph, CT scan, and MRI scan of a 15-year-old boy who has lateral ankle pain. What is the most likely diagnosis?

Options:

Stress fracture of the calcaneus
Rupture of the plantar fascia
Early traumatic arthritis of the subtalar joint
Calcaneonavicular fibrous coalition
Disruption of the os peroneum

Correct Answer: Calcaneonavicular fibrous coalition

Explanation:

Question 83:

Which of the following is most commonly inherited as a X-linked recessive disorder? Review Topic

Options:

Charcot-Marie-Tooth disease
Marfan's syndrome
Larsen's syndrome
Duchenne's muscular dystrophy
Turner's syndrome

Correct Answer: Larsen's syndrome

Explanation:

Question 84:

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

Options:

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

Correct Answer: Cauda equina syndrome

Explanation:

Question 85:

A 4-year-old boy sustains the injury shown in Figures 10a and 10b as a result of being hit and dragged by a car. Wound closure is best accomplished by

Options:

Sural artery island flap.
Free rectus abdominis flap.
Extensor digitorum brevis flap.
Staged cross leg flap.
Split-thickness skin graft.

Correct Answer: Free rectus abdominis flap.

Explanation:

Question 86:

Options:

Ulnar neuritis
Pronator syndrome
Medial epicondylitis
Medial collateral ligament sprain
Varus extension overload

Correct Answer: Medial collateral ligament sprain

Explanation:

Question 87:

- Figure 67 shows the AP radiograph of both knees of a 26-year-old woman. A review of the patient’s medical record will most likely reveal a history of

Options:

Trauma
Hemophilia
Reiter’s syndrome
Rheumatoid arthritis
Systemic lupus erythematosus

Correct Answer: Systemic lupus erythematosus

Explanation:

Question 88:

Which of the following best describes the course of the median nerve at the elbow?

Options:

Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle
Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, deep to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle
Crosses deep to the ulnar artery, superficial to the fibrous arch of the superficialis muscle, superficial to the superficial head of the pronator teres muscle

Correct Answer: Crosses superficial to the ulnar artery, deep to the fibrous arch of the superficialis muscle, deep to the superficial head of the pronator teres muscle

Explanation:

Question 89:

Osteoporotic vertebral compression fractures are associated with Review Topic

Options:

neurologic deterioration in 33% of patients.
osteomalacia in 50% of patients.
a further fracture risk rate of 20%.
chronic pain in 75% of patients.
a 2-year mortality rate that is less than that associated with hip fractures.

Correct Answer: a further fracture risk rate of 20%.

Explanation:

Question 90:

Options:

infection.
instability.
loosening.
periprosthetic fracture.

Correct Answer: instability.

Explanation:

Question 91:

- A 14-year-old patient who has homocystinuria and is Risser 3 is referred for surgical treatment of scoliosis. In addition to the usual risks associated with posterior spinal fusion, the family should be advised that the patient ‘s underlying condition significantly increases the perioperative risk of

Options:

Spinal pseudoarthrosis
Spinal cord traction injury with paralysis
Arterial and venous thromboses
Superior mesenteric artery syndrome
Crankshaft phenomenon

Correct Answer: Arterial and venous thromboses

Explanation:

Question 92:

Figures 9a and 9b show the spinal radiographs of a 3-year-old child with short limb dwarfism. The lateral radiograph is obtained with maximal lumbar extension. Management should consist of

Options:

close clinical follow-up.
a thoracolumbosacral orthosis.
anterior spinal fusion.
posterior spinal fusion.
fibroblast growth factor replacement.

Correct Answer: a thoracolumbosacral orthosis.

Explanation:

Question 93:

Which of the following best describes the recommended treatment for a 13-year-old pitcher with a painful chronic stress injury to the proximal humeral physis as confirmed on an MRI scan? Review Topic

Options:

Brief shoulder immobilization followed by avoidance of pitching and throwing for the remainder of the season
Brief shoulder immobilization followed by avoidance of pitching and throwing until skeletal maturity
In situ screw fixation of the proximal humeral growth plate
Arthroscopic shoulder debridement
Arthroscopic repair of the Bankart lesion

Correct Answer: Brief shoulder immobilization followed by avoidance of pitching and throwing for the remainder of the season

Explanation:

Question 94:

When performing a cruciate-retaining total knee arthroplasty, trial components are inserted. The knee comes to full extension but is tight in flexion. The surgeon should consider

Options:

flexing the femoral component.
releasing the posterior cruciate ligament.
downsizing the tibial insert thickness.
resecting more distal femur.

Correct Answer: releasing the posterior cruciate ligament.

Explanation:

DISCUSSION
In this scenario, the flexion gap needs to be increased. Increase in flexion gap can be accomplished by downsizing the femoral component and increasing posterior tibial slope. In posterior cruciate-retaining TKA procedures, recession or release of the posterior cruciate ligament can loosen the flexion gap, allowing for an increase in flexion. Flexing the femoral
component tightens the flexion gap, and downsizing the tibial insert thickness decreases flexion and extension gaps, while resection of the distal femur only increases the extension gap.
CLINICAL SITUATION FOR QUESTIONS 52 THROUGH 55
Figure 52 is the standing anteroposterior radiograph of a 55-year-old man who has a 5-year history of daily left knee pain with weight-bearing activities. He denies night pain or symptoms of instability. Upon examination his range of motion is 0 to 140 degrees. He has a mild, fully correctable varus deformity and a negative Lachman test result. He has failed nonsurgical treatment.

Question 95:

Options:

Left upper thoracic curve 16 degrees and right main thoracic curve 18 degress, Risser stage in figure B
Right thoracolumbar curve 35 degrees, Risser stage in figure C
Left upper thoracic curve 15 degrees and right main thoracic curve 30 degrees, Risser stage in figure B
Left upper thoracic curve 26 degrees and right main thoracic curve 51 degrees, Risser stage in figure A
Left thoracolumbar curve 19 degrees, Risser stage in figure A

Correct Answer: Left upper thoracic curve 16 degrees and right main thoracic curve 18 degress, Risser stage in figure B

Explanation:

Question 96:

Options:

It is safe to return to play right away.
It is safe to return to play if there is no airway obstruction from adenopathy.
It is safe to play due to the low risk of disease transmission to other players.
It is safe to play after 3 to 4 weeks.
It is unsafe to play the next season.

Correct Answer: It is safe to play after 3 to 4 weeks.

Explanation:

Question 97:

It is recommended that invasive dental work be completed prior to the initiation of which of the following medications?

Options:

Glucosamine
Cholecalciferol
Levothyroxine
Teriparatide
Bisphosphonates

Correct Answer: Glucosamine

Explanation:

Question 98:

Options:

hypokalemia.
administration of warfarin.
administration of antibiotics.
general anesthesia.
early mobilization and physical therapy.

Correct Answer: hypokalemia.

Explanation:

Question 99:

Options:

Clostridium
Acinetobacter
Pseudomonas
Mycobacterium
Staphylococcus aureus

Correct Answer: Clostridium

Explanation:

Question 100:

Refers to the effectiveness of various antibiotics against a particular microorganism.

Options:

Minimum inhibitory concentration (MIC)
Minimum bactericidal concentration (MBC)
Antiobiotic susceptibility
Antibiograms
Antimicrobial resistance
Spectrum of coverage

Correct Answer: Antiobiotic susceptibility

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

Orthopedic Board Review MCQs: Knee, Nerve, Revision & Shoulder Surgery | Part 189

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 189

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index