OITE & ABOS Orthopedic Board Prep: Trauma & Nerve MCQs

About This Board Review Set

This is Part 96 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

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

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Two distinct learning modes are available:

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

Topics Covered in Part 96

This module focuses heavily on: Fracture, Nerve.

Sample Questions from This Set

Sample Question 1: What is the most common long-term complication of the fracture shown in Figure 32?...

Sample Question 2: In a postganglionic brachial plexus lesion at Erb’s point (point of formation of the upper trunk by the C5 and C6 nerve roots), which of the following nerves will still function normally?...

Sample Question 3: The plate seen in Figure 48a was applied to the fracture seen in Figure 48b, and is functioning in what capacity?...

Sample Question 4: -A 17-year old boy who sustained a closed clavicle fracture after he was ejected from an all-terrain vehicle was treated with a figure-of-8 brace 1 year ago. He now reports continuous pain at the site of the fracture and is unable to active...

Sample Question 5: A 12-year-old girl has a 4-cm limb-length discrepancy following a fracture of the left distal femur 2 years ago. Examination reveals 18 degrees of genu valgum on the involved side, with 7 degrees of genu valgum on the opposite side. Radiogr...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam

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Question 1

What is the most common long-term complication of the fracture shown in Figure 32?

Explanation

DISCUSSION: The fracture pattern shown in the radiograph involves both a talar neck fracture and a talar body fracture. The body fracture propagates into the subtalar joint, with significant risk for the development of arthritis in that surface even with an anatomic reduction. In addition, Canale and Kelly reported a 25% incidence of malunion of talar neck fractures, with varus angulation occurring most frequently. Of these patients, 50% required a secondary surgical procedure because of the development of degenerative joint disease of the subtalar joint.
REFERENCES: Canale ST, Kelly FB Jr: Fractures of the neck of the talus: Long-term evaluation of seventy-one cases. J Bone Joint Surg Am 1978;60:143-156.
Higgins TF, Baumgaertner MR: Diagnosis and treatment of fractures of the talus: A comprehensive review of the literature. Foot Ankle Int 1999;20:595-605.

Question 2

In a postganglionic brachial plexus lesion at Erb’s point (point of formation of the upper trunk by the C5 and C6 nerve roots), which of the following nerves will still function normally?

Explanation

DISCUSSION: In a postganglionic injury to the brachial plexus, the rhomboid muscle, innervated by the dorsal scapular nerve, would still be expected to function. This is a useful clinical sign that the brachial plexus lesion is postganglionic as opposed to preganlionic. The musculocutaneous, axillary, and suprascapular nerves are all located distal to Erb’s point (the most common location of an upper nerve root brachial plexus injury), and all contain fibers from the C5 and C6 nerve roots. Therefore, these nerves are not expected to function normally following a postganglionic C5 and C6 nerve root injury.
REFERENCES: 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 28-29.
Zimmerman NB, Weiland AJ: Assessment and monitoring of brachial plexus injury in the adult, in Gelberman RH (ed): Operative Nerve Repair and Reconstruction. Philadelphia, PA,

JB Lippincott, 1991, vol 2, pp 1273-1283.

Question 3

The plate seen in Figure 48a was applied to the fracture seen in Figure 48b, and is functioning in what capacity?

Explanation

DISCUSSION: A Weber type B ankle fracture occurs with a supination external rotation mechanism of injury. The fibula generally fails with a spiral fracture pattern. The lag screws provide compression, and the plate acts to neutralize rotational and angular bending forces. A buttress plate resists vertical shear forces. A tension band is used over areas that may fail in tension, such as an olecranon fracture. Compression is provided by the lag screws, and distraction is again resisted by the lag screws.
REFERENCE: Mazzoca AD: Principles of internal fixation, in Browner BD, Jupiter JB, Levine AM, et al (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 308-309.

Question 4

A 17-year old boy who sustained a closed clavicle fracture after he was ejected from an all-terrain vehicle was treated with a figure-of-8 brace 1 year ago. He now reports continuous pain at the site of the fracture and is unable to actively raise his arm above his head. A radiograph is shown in Figure 1. Management should now include

Explanation

The radiograph illustrates a middle third clavicular fracture with bone loss. According to Jupiter and associates, the biomechanics of the clavicle predisposes the middle third to be prone for fracture secondary to both moments of tension and bending and also torsional forces. In their study, fixation was best accomplish with plate fixation and a bone graft.[JBJS 1987, 69-A pg. 753-759]
Selection (1) would not provide adequate fixation to promote healing. (2) Electrical stimulation would not be sufficient for the above reasons. (3) Resection of the distal clavicle would not be indicate for this case because it promote further instability of the clavicle and increasing the affected forces to the clavicle.
(5) Kirschner wire fixation with bone graft, the author stated would provide fixation, but they achieved better results with plate fixation and bone graft Question 6 -
A 75-year-old woman sustains a fracture below the level of a total hip prosthesis. Radiographs demonstrate loosening of the prosthetic component. Treatment should consist of
a cast brace
a spica cast
plate fixation
allograft strut fixation
long stem revision
The key to this question lies in the radiographic evidence of loosening of the prosthetic component. The long stem revision is clearly indicated in this case because of various factors, one decreases impingement of the loose stem against the lateral femoral cortex. A non-surgical approach in the elderly patient will only increase the many risk factors such as atelectasis, pneumonia, and thromboembolic disease.[Instructional Course 44 pg. 293-303]

Question 5

A 12-year-old girl has a 4-cm limb-length discrepancy following a fracture of the left distal femur 2 years ago. Examination reveals 18 degrees of genu valgum on the involved side, with 7 degrees of genu valgum on the opposite side. Radiographs show that the left distal femoral growth plate is now closed; however, the tibial growth plate is still open. Her bone age matches her chronologic age. Management should consist of

Explanation

DISCUSSION: The patient has a projected limb-length discrepancy of 7 cm. This includes the 4 cm she already has, plus 3 cm expected growth of the uninvolved distal femur during the 3 years of growth she has remaining. She also has moderate limb deformity. Femoral lengthening is considered the treatment of choice because it can address both the limb-length discrepancy and the deformity. Epiphyseodesis will not result in limb-length equality at maturity, with only approximately 1.8 cm of equalization expected from this procedure. Use of closed femoral shortening of 7 cm runs the risk of weakening the quadriceps on the normal side and will leave the patient with a remaining residual valgus deformity. Tibial lengthening will leave the knees at different levels. A shoe lift can be prescribed as a temporary measure but is not a good

long-term solution.
REFERENCES: Westh RN, Menelaus MB: A simple calculation for the timing of epiphyseal arrest: A further report. J Bone Joint Surg Br 1981;63:117-119.
Sasso RC, Urquhart BA, Cain TE: Closed femoral shortening. J Pediatr Orthop 1993;13:51-56.
Nordsletten L, Holm I, Steen H, Bjerkreim I: Muscle function after femoral shortening osteotomies at the subtrochanteric and mid-diaphyseal level: A follow-up study. Arch Orthop Trauma Surg 1994;114:37-39.

Question 6

Figures 23a through 23h are the radiographs and MR images of a 32-year-old man with worsening left knee pain. A 3-foot hip-to-ankle radiograph shows a 13-degree varus knee deformity. The patient sustained a major left knee injury 5 years ago and a confirmed complete anterior cruciate ligament (ACL) tear. He managed this injury nonsurgically with a functional brace but experienced worsening pain. He was seen by an orthopaedic surgeon 18 months ago and a medial meniscus tear was diagnosed; the tear was treated with an arthroscopic partial medial meniscectomy. Since then, his knee has been giving way more often and he no longer feels safe working on a pitched roof. The patient received 6 months of formal physical therapy and was fitted for a new functional ACL brace, but he still has pain and instability symptoms. He believes he has exhausted his nonsurgical options and would like to undergo surgery. What is the most appropriate treatment at this time?

Explanation

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

Question 7

What is the treatment of choice for an adult who has an isolated fracture of the ulna at the junction of the distal and middle thirds, with 5 degrees apex dorsal angulation and 25% displacement?

Explanation

This is the correct answer for various reasons, based on the question. Key points isolated fracture, distal and middle thirds, and only 25% displace. The author is implying minimal displacement. According to Gebuhr, Holmich a fracture such as describe in the question which does not require close reduction and only initial mobilization are better satisfied with a functional brace. Their study revealed that elbow extension/flexion and forearm pronation/supination had no difference with long arm cast, but wrist extension/flexion greatly improved with the functional bracing. Selections (1) more indicated for midshaft (3) is not inappropriate, but the authors felt it was not necessary because there was greater patient satisfaction with functional bracing and same results except wrist motion was better. (4), (5) are indicated for greater severity of fracture and failed union.

Question 8

What is the most common complication after distal biceps tendon repair at the elbow?

Explanation

EXPLANATION:
Cain and associates retrospectively reviewed 198 consecutive surgical repairs of the biceps and noted a 36% overall complication rate, including 26% paresthesia of the lateral antebrachial cutaneous nerve, 6% paresthesia of the sensory branch of the radial nerve, 2% superficial infection, 4% injury to the posterior interosseous nerve, 3% symptomatic heterotopic ossification, and 2% rerupture. Grewal and associates randomized 47 patients to have single-incision repair with two suture anchors and 44 patients to have two-incision transosseous suture repair. They reported that the single-incision technique had a higher rate of transient neurapraxia to the lateral antebrachial cutaneous nerve, affecting 19 of 47 in the suture anchor group and three of 43 in the transosseous group. Also, four reruptures occurred, which appeared to be independent of the repair technique. Recordon and associates found only three complications in their series of 46 patients, 19 having endobutton repair and 27 with transosseous suture repair. They reported two injuries to the lateral antebrachial cutaneous nerve and one case of heterotopic ossification. The review by Banerjee and associates showed one rupture of repair (disengagement of the cortical button), two persistent lesions of the superficial branch of the radial nerve, and one symptomatic heterotopic ossification. Co hen remarked that rerupture of the tendon after repair is uncommon in both one-incision and two-incision techniques. Van den Bogaerde and Shin presented a case of posterior interosseous nerve
incarceration with endobutton repair.

Question 9

Which of the following growth factors binds and activates the lipoprotein receptor-related protein 5/6 (LRP5/6) during bone development? Review Topic

Explanation

Wnt and Hedgehog (Hh) signaling pathways are key regulators of bone formation. Mutations in the Wnt and Hh pathways result in skeletal malformations as well as osteoarthritis. Wnts are a large family of secreted proteins (19 different members in the human genome) that transduce their signal through several pathways. The most studied of these pathways is the Wnt/beta-catenin pathway, in which Wnt protein binds to the LRP5/6 receptor at the cell surface and activates an intracellular cascade. This cascade leads to translocation of beta-catenin into the nucleus to activate transcription of genes that control osteoblast differentiation. Agents that stimulate this pathway are under investigation for treatment of osteoporosis.

Question 10

A 60-year-old woman with a history of breast cancer has progressive paraparesis. The MRI scan is shown in Figure 28. What form of management is most likely to restore or maintain ambulation?

Explanation

DISCUSSION: Surgical decompression and stabilization have been shown to be the most effective means of improving neurologic function. Decompression is most reliably done from the side of the compression, which is anterior in this patient.
REFERENCES: Harrington KD: Metastatic tumors of the spine: Diagnosis and treatment. J Am Acad Orthop Surg 1993;1:76-86.
Siegal T, Siegal T: Current considerations in the management of neoplastic spinal cord compression. Spine 1989;14:223-228.

Question 11

A 25-year-old man is unresponsive at the scene of a high-speed motor vehicle accident and remains obtunded. Initial evaluation in the emergency department reveals a left-sided femoral shaft fracture and a right-sided humeral shaft fracture. The cervical spine remains immobilized in a semi-rigid cervical collar, and the initial AP and lateral radiographs obtained in the emergency department are unremarkable. What is the most appropriate management at this time? Review Topic

Explanation

Clearance of the cervical spine can be difficult in the obtunded or unresponsive patient. Various trauma series have been reported to detect up to 95% of cervical fractures but only when ideal imaging views have been obtained, which is not often possible in the unresponsive or uncooperative patient. Passively performed cervical flexion-extension under live fluoroscopy has been suggested but is not without inherent risk in the potentially unstable cervical spine. CT of the cervical spine has gained acceptance for the evaluation of these patients given the excellent evaluation of the osseous anatomy and for the common availability in most emergency departments. Sanchez and associates, using a protocol to evaluate for cervical spine injuries after blunt trauma, were able to detect 99% of cervical fractures with 100% specificity.

Question 12

A 15-year-old boy has had pain in the right shoulder for the past 3 months. He denies any history of trauma and has no constitutional symptoms. Examination reveals a large firm mass in the proximal arm. A radiograph and MRI scan are shown in Figures 27a and 27b. Biopsy specimens are shown in Figures 27c and 27d. Management should consist of

Explanation

DISCUSSION: The patient has an aneurysmal bone cyst. The fluid-fluid levels seen on the MRI scan are typical for aneurysmal bone cyst, and the histology is consistent with a cystic lining. Vascular lakes, multinucleated giant cells, reactive bone, fibrovascular tissue, and an absence of atypical cells or numerous mitoses are seen histologically. Aneurysmal bone cysts will typically continue to grow and cause further bone destruction; therefore, observation is not recommended. Steroid injections are not effective. A thorough curettage of the cyst lining and bone grafting are required. Wide resection and chemotherapy are reserved for more aggressive tumors. There is no evidence of infection radiographically or histologically. Telangiectatic osteosarcoma should also be considered in the differential diagnosis; therefore, biopsy is an important part of the work-up.
REFERENCES: Wold LA, et al: Atlas of Orthopaedic Pathology. Philadelphia, PA, WB Saunders, 1990, pp 232-233.
Simon M, et al: Surgery for Bone and Soft Tissue Tumors. Philadelphia, PA, Lippincott Raven, 1998, pp 194-196.

Question 13

Figures 177a and 177b are the radiographs of a 7-year-old boy with spastic cerebral palsy. He has quadriparetic involvement and is unable to ambulate. He has very limited abduction, 30 degrees of flexion contractures, and pain on abduction. Bilateral varus osteotomies are scheduled with acetabular procedures to improve stability. Which type of acetabular osteotomy should be performed?

Explanation

Question 14

According to Musculoskeletal Infection Society (MSIS) guidelines, which set of patient laboratory study results fits the definition of chronic prosthetic joint infection?

Explanation

DISCUSSION:
The MSIS definition of periprosthetic joint infection was updated in 2014 with two major and six minor criteria. The presence of one major criterion or three minor criteria is diagnostic for infection. The major criteria are two positive cultures with the same organism or a draining sinus tract. The current MSIS minor criteria are 1) an elevated ESR (more than 30 mm/hr) and CRP level (more than 10 mg/L), 2) an elevated synovial WBC count (more than 3,000 cells per/microliter), 3) an elevated synovial fluid polymorphonuclear count (more than 80%), 4) a positive histological analysis of periprosthetic tissue, and 5) a single positive culture.

Question 15

A 57-year-old man involved in a motor vehicle accident sustains an injury to his right shoulder. A spot AP radiograph is shown in Figure 34. What is the next most appropriate step in the orthopaedic management of this patient?

Explanation

DISCUSSION: The next step in the management of this injury is completion of the shoulder trauma series. An axillary radiograph, which can be quickly performed in the emergency department, must be obtained to accurately assess the humeral head relationship to the glenoid. If difficulty is encountered, a “Velpeau” axillary may be substituted. If that fails to elucidate the status of the glenohumeral joint, a CT scan should be obtained.
REFERENCE: Simon JA, Puopolo SM, Capla EL, et al: Accuracy of the axillary projection to determine fracture angulation of the proximal humerus. Orthopedics 2004;27:205-207.

Question 16

When comparing the addition of a trough at the greater tuberosity to direct repair of cortical bone, simulated rotator cuff repair in animal models has shown what type of change in the strength of the repair?

Explanation

DISCUSSION: There was no difference observed in the healing of tendon to bone when comparing healing to cortical bone and to a cancellous trough.
REFERENCE: St Pierre P, Olson EJ, Elliott JJ, et al: Tendon healing to cortical bone compared with healing to a cancellous trough. J Bone Joint Surg Am 1995;77:1858-1866.

Question 17

A 34-year-old man underwent a transtibial amputation as the result of a work-related injury. The amputation was performed at the inferior level of the tibial tubercle. The residual limb has a soft-tissue envelope composed of gastrocnemius muscle that is used as soft-tissue cushioning for the distal tibia. Despite undergoing several prosthetic fittings, he continues to report pain and instability. Examination reveals that the prosthesis appears to fit well with no apparent pressure points or areas of skin breakdown. He is not willing to have any further surgery. Which of the following modifications will most likely provide relief?

Explanation

DISCUSSION: While transtibial amputees can be fitted with a prosthesis with a residual limb as short as 5 cm, or with retention of the insertion of the patellar tendon, this patient has an unstable gait because of the limited ability of the prosthetic socket to maintain a snug and stable fit. While cumbersome and bulky, double metal uprights and a corset is the only predictable method of gaining stability. The other methods attempt to add an element of stability; however, they are unlikely to be successful.
REFERENCES: Bowker JH, Goldberg B, Poonekar PD: Transtibial amputation: Surgical procedures and postsurgical management, in Bowker JH, Michael JW (eds): Atlas of Limb Prosthetics. St Louis, MO, Mosby Year Book, 1992, pp 429-452.
Kapp S, Cummings D: Transtibial amputation: Prosthetic management, in Bowker JH, Michael JW (eds): Atlas of Limb Prosthetics. St Louis, MO, Mosby Year Book, 1992, pp 453-478.

Question 18

A 60-year-old man is evaluated in the ICU after a rollover motor vehicle accident 3 days ago. He has multiple upper and lower extremity trauma and was found unresponsive at the accident scene. Surgery is planned for the extremity trauma once the patient is medically stable. He remains intubated and the cervical spine is immobilized in a semi-rigid collar. Examination reveals mild erythema in the posterior occipital cervical region. Initial AP and lateral radiographs of the cervical spine have not revealed any obvious fracture. What is the most appropriate treatment option at this time?

Explanation

DISCUSSION: Ackland and associates demonstrated that the failure to achieve early spinal clearance in an unconscious blunt trauma patient predisposed the patient to increased morbidity secondary to the prolonged used of cervical immobilization. They demonstrated that the four significant predictors of collar-related ulcers were ICU admission, mechanical ventilation, the necessity for cervical MRI, and the time to cervical spine clearance and collar removal. The risk of pressure-related ulceration increased by 66% for every 1-day increase in Philadelphia collar time and this highlights the need for definitive C-spine clearance.
REFERENCES: Ackland HM, Cooper DJ, Malham GM, et al: Factors predicting cervical collar-related decubitus ulceration in major trauma patients. Spine 2007;32:423-428.
Hewitt S: Skin necrosis caused by semi-rigid cervical collar in a ventilated patient with multiple injuries. Injury 1994;25:323-324.

Question 19

Atraumatic neuropathy of the suprascapular nerve usually occurs at what anatomic location?

Explanation

DISCUSSION: The suprascapular nerve passes through the suprascapular notch and the spinoglenoid notch before innervating the infraspinatus muscle. At both locations, the suprascapular nerve is prone to nerve compression, which often results from a ganglion cyst. The other anatomic locations are not associated with suprascapular nerve impingement.
REFERENCES: Romeo AA, Rotenberg DD, Bach BR: Suprascapular neuropathy. J Am Acad Orthop Surg 1999;7:358-367.
Post M, Mayer J: Suprascapular nerve entrapment: Diagnosis and treatment. Clin Orthop 1987;223:126-136.

Question 20

A 47-year-old woman has a painful bunion of the right foot, and shoe wear modifications have failed to provide relief. Examination reveals a severe hallux valgus with dorsal subluxation of the second toe. Radiographs are shown in Figures 14a and 14b. The most appropriate management should include

Explanation

DISCUSSION: The radiographs do not show significant arthrosis of the hallux metatarsophalangeal joint; therefore, arthrodesis is unnecessary. Orthotics will not correct the deformity. A distally based osteotomy will not achieve sufficient correction of the incongruity of deformity, and a Keller resection is not indicated in the younger population. The treatment of choice is a proximal metatarsal osteotomy with second toe correction.
REFERENCE: Mann RA, Rudicel S, Graves SC: Repair of hallux valgus with a distal soft-tissue procedure and proximal metatarsal osteotomy: A long-term follow-up. J Bone Joint Surg Am 1992;74:124-129.

Question 21

What form of fixation is associated with the highest incidence of osseous union when using segmental allograft reconstruction following tumor resection?

Explanation

DISCUSSION: Plate and screw fixation of allograft is associated with the highest incidence of union but also the highest prevalence of allograft fracture. Conversely, intramedullary fixation is associated with a higher incidence of nonunion but fewer fractures. Step-cut osteotomies are not associated with a higher incidence of union.
REFERENCE: Vander Griend RA: The effect of internal fixation on the healing of large allografts. J Bone Joint Surg Am 1994;76:657-663.

Question 22

A 46-year-old man has acute tenderness along the ulnar aspect of the wrist after falling on his outstretched hand while playing basketball. Examination reveals tenderness and mild swelling along the volar ulnar aspect of the wrist. Radiogaphs are shown in Figures 14a through 14c. Management should consist of

Explanation

DISCUSSION: The PA view of the wrist shows a pisiform fracture. Pisiform fractures constitute 1% to 3% of all carpal bone fractures. This fracture can be further evaluated with a carpal tunnel view or a supination oblique view of the wrist. Initial management should consist of immobilization with a short arm cast. If nonsurgical measures fail, bony excision is warranted.
REFERENCES: Failla JM, Amadio PC: Recognition and treatment of uncommon carpal fractures. Hand Clin 1988;4:469-476.
Botte MJ, Gelberman RH: Fractures of the carpus, excluding the scaphoid. Hand Clin 1987;3:149-161.

Question 23

Figure 12 shows the radiograph of a 55-year-old man who has severe, painful osteoarthritis of the left hip and is scheduled to undergo a left total hip arthroplasty. History reveals that he underwent a right total hip arthroplasty 5 years ago that remains pain-free. Based on the preoperative radiograph, the patient is at greatest risk for what complication?

Explanation

DISCUSSION: The patient is at increased risk for limb-length discrepancy because the radiograph shows that the left leg is already longer than the right leg. To restore the proper biomechanics of the left hip, the left leg may have to be lengthened, further increasing the limb-length discrepancy. Intraoperative fracture, deep vein thrombosis, sciatic nerve palsy, and thigh pain are commonly associated with total hip arthroplasty, but the patient is not at increased risk for these complications.
REFERENCE: Ranawat CS, Rodriguez JA: Functional leg-length inequality following total hip arthroplasty. J Arthroplasty 1997;12:359-364.

Question 24

Deep anterior compartment

Explanation

How many compartments exist in the foot:

Question 25

A surgeon desires to use an implant that will be able to absorb as much energy as possible before it fails. The implant should be made of a material that has which of the following properties?

Explanation

High intrinsic toughness is defined as the amount of energy per volume a material can absorb without breaking. A high modulus of elasticity and a low modulus of elasticity are incorrect because the modulus of elasticity refers to the stiffness of the material. A brittle material absorbs little energy before breaking. High yield stress is incorrect because it is only one of several factors that lead to a high toughness. While the yield stress is the point at which plastic deformation begins, if coupled with a brittle material, the energy absorbed would be low relative to a ductile material.

Question 26

When evaluating articular cartilage, what extracellular matrix component is most closely associated with the deep calcified cartilage zone?

Explanation

DISCUSSION: Collagen type X is produced only by hypertrophic chondrocytes during enchondral ossification (growth plate, fracture callus, heterotopic ossification) and is associated with calcification of cartilage in the deep zone of articular cartilage. Collagen type I is the predominant collagen in bone, ligament, and tendon. Collagen type II is the predominant collagen in articular cartilage. Proteoglycan aggrecan and hyaluronic acid are components of the extracellular matrix and are involved in the compressive strength characteristics of articular cartilage.
REFERENCES: Buckwalter JA, Mankin HJ: Articular cartilage: Tissue design and chondrocyte matrix interactions. Instr Course Lect 1998;47:477-486.
Poole AR, Kojima J, Yasuda T, Mwale F, Kobayasai M, Laverty S: Composition and structure of articular cartilage: A template for tissue repair. Clin Orthop 2001;391:S26-S33.
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Question 27

A 22-year-old patient underwent successful reduction of a posterolateral elbow dislocation. Management should now consist of

Explanation

DISCUSSION: The elbow usually is stable after reduction in most elbow dislocations. Ross and associates reported that supervised motion begun immediately after reduction was effective in uncomplicated dislocations. The elbow will become stiff if immobilization is applied for an extended period of time. Immediate open treatment is not indicated for a simple elbow dislocation.
REFERENCES: Ross G, McDevitt ER, Chronister R, et al: Treatment of simple elbow dislocation using an immediate motion protocol. Am J Sports Med 1999;27:308-311.
O’Driscoll SW, Jupiter JB, King GJ, et al: The unstable elbow. J Bone Joint Surg Am 2000;82:724-738.

Question 28

The teardrop shape marked with an asterisk in Figure 61 represents what anatomic structure?

Explanation

DISCUSSION: The teardrop can be visualized on the obturator outlet view of the pelvis and represents a thick column of bone that runs from the AIIS to the PSIS. Half pins for eternal fixation frames or screws can be inserted into this column for fixation of fractures.
REFERENCES: Gardner MJ, Nork SE: Stabilization of unstable pelvic fractures with supra-acetabular compression external fixation. J Orthop Trauma 2007;21:269-273.
Haidukewych GJ, Kumar S, Prpa B: Placement of half-pins for supra-acetabular external fixation: An anatomic study. Clin Orthop Relat Res 2003;411:269-273.
Kim WY, Hearn TC, Seleem O, et al: Effect of pin location on stability of pelvic external fixation. Clin Orthop Relat Res 1999;361:237-244.

Question 29

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 30

A 9-year-old child has right groin pain after falling from a tree. Examination reveals that the right leg is held in external rotation, and there is significant pain with attempts at passive range of motion. Radiographs are shown in Figures 43a and 43b. Management should consist of

Explanation

DISCUSSION: The complications of femoral neck fractures in children include osteonecrosis, malunion, nonunion, and premature physeal closure. It is presumed that the risk of osteonecrosis is directly related to the amount of displacement at the time of injury and is not affected by the type of treatment. The risk of the other complications can be decreased depending on the type of treatment. Anatomic reduction by either closed or open methods can reduce the risk of malunion. The addition of internal fixation allows for maintenance of the reduction. In young children who cannot comply with a partial or non-weight-bearing status, the addition of a spica cast gives added protection.
REFERENCES: Canale ST: Fractures of the hip in children and adolescents. Orthop Clin North Am 1990;21:341-352.
Hughes LO, Beaty JH: Fractures of the head and neck of the femur in children. J Bone Joint Surg Am 1994;76:283-292.

Question 31

When using surgery extending to the pelvis to treat long spinal deformity in adults, the addition of anterior interbody structural support at the lumbosacral junction serves what biomechanical function?

Explanation

DISCUSSION: Shufflebarger and others have reported that the placement of anterior interbody structural support at the lumbosacral junction increases the overall construct stiffness and reduces the strain on posterior instrumentation, thereby reducing the risk of screw pull-out or fracture. The stiffness of the posterior instrumentation actually increases, whereas the actual strength of the instrumentation remains the same. Actual strain measured at an adjacent intervertebral disk to a fusion construct is expected to increase.
REFERENCES: Shufflebarger HL: Moss-Miami spinal instrumentation system: Methods of fixation of the spondylopelvic junction, in Margulies JI, Floman Y, Farcy JPC, et al (eds): Lumbosacral and Spinal Pelvic Fixation. Philadelphia, PA, Lippincott-Raven, 1996, pp 381-393.
Cunningham BW: A biomechanical approach to posterior spinal instrumentation: principles and applications, in DeWald RL (ed): Spinal Deformities: A Comprehensive Text. New York, NY, Thieme, 2003, pp 588-600.
Kostuik JP, Valdevit A, Chang HG, et al: Biomechanical testing of the lumbosacral spine. Spine 1998;23:1721-1728.

Question 32

A 43-year-old woman has had pain in the left hip for the past 2 months. A radiograph, CT scan, MRI scan, and biopsy specimens are shown in Figures 16a through 16e. What is the most likely diagnosis?

Explanation

DISCUSSION: The imaging studies are consistent with a chondrosarcoma. The radiograph shows a radiolucent lesion in the pelvis, and there are stippled calcifications on the CT scan. The histology shows a low-grade cellular hyaline cartilage neoplasm with stellate, occasionally binucleated chondrocytes. Enchondroma has a more benign histologic appearance.
REFERENCE: Mirra JM, Gold R, Downs J, Eckardt JJ: A new histologic approach to the differentiation of enchondroma and chondrosarcoma of the bones: A clinicopathologic analysis of 51 cases. Clin Orthop 1985;201:214-237.

Question 33

A 3-year-old child has refused to walk for the past 2 days. Examination in the emergency department reveals a temperature of 102.2 degrees F (39 degrees C) and limited range of motion of the left hip. An AP pelvic radiograph is normal. Laboratory studies show a WBC count of 9,000/mmP3P, an erythrocyte sedimentation rate (ESR) of 65 mm/h, and a C-reactive protein level of 10.5 mg/L (normal < 0.4). What is the next most appropriate step in management? Review Topic

Explanation

No further treatment
Continue Pavlik Harness treatment
Convert to semi-rigid abduction brace
Perform a hip arthrogram with closed vs. open reduction under general anesthesia
Perform a pelvic osteotomy
This is a 4 week old infant with DDH who has failed Pavlik harness treatment for 3 weeks. Figure A is an ultrasound image demonstrating a dislocated hip.
Initial treatment for an infant with a dislocated, but reducible ("Ortolani positive") hip is bracing in a Pavlik Harness. The Pavlik harness is a dynamic brace that requires normal muscle function and tone to help keep the hip in a reduced position. If this treatment fails to hold the hip reduced after three weeks of treatment, the harness should be discontinued to prevent "Pavlik Harness Disease" which involves erosion of the posterior acetabulum as the femoral head is inappropriately being held against it.
After failure of Pavlik harness treatment, if the hip remains subluxated, the next step in treatment is to convert to a semi-rigid orthosis of another 2-3 weeks. If the semi-rigid brace likewise fails to keep the hip reduced, then hip arthrogram with closed vs. open reduction and spica-cast placement can be planned.
Swaroop and Mubarak present a study using a protocol of initial pavlik harness treatment with weekly ultrasound assessment for 3 weeks. If the hip remained unstable but reducible, then semi-rigid abduction bracing with continues weekly ultrasounds were done for an additional 2-3 weeks. This treatment protocol had a 93% success rate, which compared favorably to protocols not including the abduction
brace.
Hedequist et al. presented a review of 15 patients treated similarly with intial pavlik harness treatment for 3-4 weeks, and then abduction bracing if the remained unstable but reducible. They found that abduction bracing produced a stable hip within 1-2 months.
Illustration A shows a baby wearing a semi-rigid orthosis. Illustration B is the hip ultrasound image from Figure A with labels added. Illustration C is an ultrasound of a hip that is not dislocated.
Incorrect answers:

Question 34

A patient sustains a severe lower extremity injury. What can be said about his outcome at 2 years if he chooses reconstruction over amputation?

Explanation

DISCUSSION: Severe lower extremity injury patients undergoing reconstruction have a higher rate of rehospitalization at 2 years. This question is based on data published by the LEAP study group, a multi-centered study of severe extremity injuries treated with either amputation or reconstruction.
Bosse et al found that at 2 years the SIP score and return to work were not statistically signficantly different between amputation and reconstruction groups. Reconstruction patients had a higher risk of rehospitalization. The psychosocial subscale of SIP did not improve with time. Risk factors for poorer SIP score were: rehospitalization for a major complication, a low educational level, nonwhite race, poverty, lack of private health insurance, poor social-support network, low self-efficacy (the patient's confidence in being able to resume life activities), smoking, and involvement in disability-compensation litigation.
MacKenize et al evaluated factors influential in returning to work (RTW) after severe lower extremity injury. Characteristics that correlated with higher rates of RTW included younger age, higher education, higher income, the presence of strong social support, and employment in a white-collar job that was not physically demanding. Receipt of disability compensation had a strong negative effect on RTW.

Question 35

Figures below show the radiographs, MRI, and MR arthrogram obtained from a 25-year-old collegiate soccer player who has new-onset left groin pain. He played competitive soccer from a young age and has competed or practiced 5 to 6 times per week since the age of 10. He denies any specific hip injury that necessitated treatment, but his trainer contends that he had a groin pull. He reports groin pain with passive flexion and internal rotation of the left hip, and his hip has less internal rotation than his asymptomatic right hip. He is otherwise healthy. What is the primary cause of a cam deformity?

Explanation

Multiple studies have confirmed that cam or pincer anatomy is commonly present in asymptomatic hips. According to a large systematic review, cam deformities are present in approximately one-third of asymptomatic hips in young adults, and the proportion is higher than 50% in the subgroup of athletes. Ganz and associates proposed that femoral acetabular impingement is the root cause of osteoarthritis in most nontraumatic, nondysplastic hips, and functional improvement with surgical correction of the deformity has been demonstrated. Despite the link between cam deformity and hip osteoarthritis, a corresponding link between the correction of the deformity and prevention of osteoarthritis has never been proven. The results of cam deformity correction, typically including repair of the degenerative labral tear, are much poorer when substantial joint space loss is present. A typical joint space cutoff of 2 mm or less is used to recommend against hip preservation surgery.

Question 36

In regards to a genetic disorder, which of the following is an example of "anticipation?"

Explanation

Genetic anticipation is a phenomenon in which a genetic disorder becomes progressively more severe and earlier in onset with each generation. Examples of disorders exhibiting anticipation include Huntington's disease and myotonic dystrophy.
Genetic anticipation is an important concept in understanding the development and genetic implications of many heritable disorders. It is a common phenomenon in trinucleotide repeat expansion disorders. These disorders are due to unstable microsatellite trinucleotide repeats that expand beyond the normal threshold. In subsequent generations these expansions become longer and thus express disease characteristics at a younger age of onset, and often with greater severity.
Martorell et al. investigated the development of CTG trinucleotide repeats in patients with myotonic dystrophy type 1 (DM1) and their relatives. They discovered unaffected individuals carry a pre-mutation sequence which can lead to trinucleotide repeat expansion in subsequent generations and thus produce offspring with the disorder.
Kamsteeg et al. compare the characteristics of DM1 and DM2. Both are due to trinucleotide repeat expansions. However, while DM1 can present with earlier onset and increasing severity in each generation, DM2 does not exhibit this genetic anticipation.
Incorrect Answers

Question 37

At which joint do degenerative changes occur first in a patient with chronic, untreated scapholunate dissociation?

Explanation

EXPLANATION:
Stage I of scapholunate advanced collapse (SLAC) is characterized by the presence of radioscaphoid arthritis. A predictable pattern exists of the progression of degenerative changes for SLAC wrist, including stage I (radial styloid involvement at the scaphoid fossa), stage II (scaphoid and entire scaphoid facet involvement), stage III (degeneration between the capitate and lunate), and stage IV (pancarpal involvement). The radiolunate joint is often spared.

Question 38

A 30-year-old right hand-dominant woman is seen in the trauma unit after a high-speed motor vehicle accident. She sustained a right shoulder anterior dislocation that is gently reduced under sedation. A CT scan is shown in Figure 3. If left untreated, the patient is at greatest risk for

Explanation

DISCUSSION: Large, displaced anterior inferior glenoid rim fractures predispose patients to recurrent anterior instability due to loss of the normal concavity compression effect of the glenoid. These defects require open reduction and internal fixation to reestablish shoulder stability. Although intra-articular fractures may lead to arthrosis, recurrent instability is

more common.
REFERENCES: Robinson CM, Kelly M, Wakefield AE: Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: Risk factors and results of treatment.

J Bone Joint Surg Am 2002;84:1552-1559.
Bigliani LU, Newton PM, Steinmann SP, et al: Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder. Am J Sports Med 1998;26:41-45.

Question 39

5cm. Recent radiographs are seen in Figures A and B. What is the most appropriate treatment plan?

Explanation

Posterior perforation of the distal femur
Varus malreduction
Comminution of the fracture site
Iatrogenic femoral neck fracture
Anterior perforation of the distal femur Corrent answer: 5
According to the study by Egol et al, the average femoral anterior radius of curvature was 120 cm (+/- 36 cm), and currently available femoral nails have a greater radius of curvature (i.e. more straight). This mismatch has been shown to lead to an increased risk of perforation of the anterior distal femur as the nail is impacted into the canal.
The referenced study by Tencer et al noted an increased risk of iatrogenic femoral fracture with anterior starting point >6mm from the anatomic axis.
They recommend starting in line with the femoral axis, or just a few millimeters anterior in order to minimize this risk.
Illustration A depicts anterior femoral cortex penetration secondary to nail/femur radius of curvature mismatch.

OrthoCash 2020
A 60-year-old woman is undergoing closed reduction and percutaneous pinning of a proximal humerus fracture. What structure is at greatest risk for injury from the pin marked by the red arrow in Figure A?

Anterior branch of the axillary nerve
Posterior humeral circumflex artery
Long head of the biceps tendon
Cephalic vein
Musculocutaneous nerve
Certain anatomic structures are at risk with percutaneous pinning of proximal humerus fractures. The red arrow in Figure A marks a proximal lateral pin that would place the anterior branch of the axillary nerve at risk.
Rowles and McGrory performed an anatomic study of the structures at risk with closed reduction and percuatneous pinning of the proximal humerus and found that proximal lateral pins were a mean of 3mm from the anterior branch of the axillary nerve. Pins placed through the anterior cortex and directed into the humeral head fragment were a mean of 2mm from the long head of the biceps tendon and greater tuberosity pins were found to be 8mm from the posterior humeral circumflex and 10mm from the main trunk of the axillary nerve as they penetrated the medial cortex of the humerus.
Jaberg et al retrospectively reviewed the clinical and radiographic results of 48 patients at an average of 3 years after undergoing closed reduction and percutaneous pinning of a proximal humerus fracture. 70% good to excellent results with their described technique, and the authors caution that radiographic malunion did not correlate with patient function.
Incorrect Answers

OrthoCash 2020
A 42-year-old female sustains the injury seen in the computed tomography images seen in Figures A and B. According to the Letournel classification, what is the injury pattern shown?

Posterior wall
Transverse
Anterior wall
Posterior column
Both column
The axial CT cut and Judet radiographic view shown reveals a transverse fracture pattern according to the Letournel classification system. This can be determined by the fact that the articular surface of the acetabulum is attached to the intact portion of the ilium, which is connected to the axial skeleton posteriorly through the sacroiliac joint. This differs from a both-column fracture, in which the articular surface of the acetabulum has no attachments to the axial skeleton due to fracture line(s). The axial CT scan also shows a vertical fracture line which is typical of a transverse fracture pattern.
Durkee et al review the classification schemes for these injuries, as well as comment on the importance of quality images (Judet views, CT, etc).
Figures A and B show a transverse acetabular fracture with mild displacement.

OrthoCash 2020
Which of the following is true regarding plating of humeral shaft fractures compared to intramedullary nailing?
worse functional results
higher need for subsequent surgeries
higher incidence of radial nerve injury
lower complication rates
decreased nonunion rates Corrent answer: 4
Controversy exists regarding nailing compared with plating of humeral shaft fractures, but the most recent and highest level evidence indicates decreased complication rates with open reduction and internal fixation of these injuries.
Lin et al found less blood loss with intramedullary nailing than plating, but nailing was also associated with increased shoulder surgery, likely due to disruption of the rotator cuff tendon during insertion.
Meekers et al found a higher union rate, better functional results and a lower reoperation rate after plate and screw fixation versus nailing. They concluded that plating was superior in most cases of humeral shaft fracture, however more recent studies have challenged these findings.
Heineman et al. (2012) have recently conducted an update on their meta-analysis to include more recent randomized studies. With the inclusion of newer studies the author found a statistically significant increase in total complication rate with the use of IM nailing compared with ORIF. The authors found no significant difference between the two treatment modalities for the secondary outcomes (nonunion, infection, nerve palsy, re-operation)
Incorrect Answers:
OrthoCash 2020
A 35-year-old male sustains the fracture seen in Figures A and B. Which of the following substances has been shown to result in the least radiographic subsidence when combined with open reduction and internal fixation?

Cancellous allograft bone chips
Autograft iliac crest
Femoral intramedullary reamings
Calcium phosphate cement
Calcium sulfate cement Corrent answer: 4
Figures A and B show a plateau fracture with a lateral split and depression of the articular surface. In treating tibial plateau fractures, calcium phosphate has been shown to have the least amount of articular subsidence on follow-up examinations due to its high compressive strength.
The study by Lobenhoffer et al noted improved radiographic outcomes and earlier weightbearing with usage of calcium phosphate cement. Welch and Zhang reproduced tibial plateau fractures in goats and compared cancellous autograft to calcium phosphate cement augmentation. At 24 hours, four of five specimens treated with autograft had subsidence of the fragment. Only two specimens from limbs treated with cement showed minimal subsidence; the remaining were congruent.
Yetkinler’s study compared cement to no cement treatment in a model of depressed plateau fractures. Calcium phosphate cement of high compressive
strength provided equivalent or better stability than conventional open reduction
and internal fixation with either auto/allograft bone which had both a lower compressive strength and reduced mechanical stability.
OrthoCash 2020
The modified Judet approach to the posterior scapula exploits the internervous interval between what two muscles?
Supraspinatus and infraspinatus
Supraspinatus and subscapularis
Infraspinatus and teres minor
Teres minor and teres major
Teres major and lattisimus Corrent answer: 3
The posterior or modified Judet approach to the scapula is typically used for internal fixation of scapular fractures. This approach utilizes a transverse incision over the scapular spine with detachment of the posterior deltoid. The interval between the infraspinatus (suprascapular n.) and teres minor (axillary n.) is identified and used to gain access to the posterior aspect of the scapula and glenoid.
The reference by Obremskey et al argues the approach "combines several important goals including: 1) exposure of all bony elements of the scapula which have adequate bone stock for internal fixation; 2) minimal trauma to the rotator cuff musculature; and 3) protection of the major neurologic structures (suprascapular nerve superiorly and axillary nerve laterally)." They believe "the main advantage of the exposure is limiting muscular dissection, which can potentially improve rehabilitation and limit morbidity of the operation."
OrthoCash 2020
An 82-year-old female sustains an intertrochanteric hip fracture and is treated with a sliding hip screw. What is the most appropriate definitive step in treating the failure seen in figure A?

Non-weight bearing
Valgus proximal femoral osteotomy
Total hip arthroplasty
Revision open reduction and internal fixation
Proximal femoral resection Corrent answer: 3
Figure A shows superior cutout of the lag screw from the sliding hip screw as well as the superior cannulated screw used for an "antirotation" device.
In the referenced review article by Haidukewych and Berry, salvage of failed treatment of hip fractures in the elderly is limited by bone quality and comorbidities. They recommend total hip arthroplasty in this instance to restore function, decrease pain, and limit periods of immobilization. They mention that the major challenges for arthroplasty are: assessing the need for acetabular resurfacing, selecting the femoral implant, and managing the greater trochanter.
OrthoCash 2020
A 13-year-old boy falls out of a tree and sustains the injury seen in Figures A and B. He is taken to the OR for fixation of his fracture.
The next morning, the patient’s blood pressure is 185/105 mm Hg and pulse rate is 130. He complains of pain that is not improved with opiates. On physical exam, the foot is firm. The decision is made to obtain compartment pressures to rule out compartment syndrome of the foot. Which of the following paths in Figure C marks the
appropriate location to measure the central compartment, and what would be considered abnormal values?

Path A, absolute value of 30-45 mmHg or delta p > 30mmHg
Path B, absolute value of 30-45 mmHg or delta p > 30mmHg
Path B, absolute value of 30-45 mmHg or delta p < 30mmHg
Path C, absolute value of 30-45 mmHg or delta p > 30mmHg
Path C, absolute value of 30-45 mmHg or delta p < 30mmHg Corrent answer: 3
The correct approach to measure pressures in the central compartment of the foot is by directing the needle lateral and plantar through the abductor hallicus, just under the base of the first metatarsal. Abnormal values indicating the need for decompression are an absolute value of 30-45 mmHg or a Δp < 30mmHg (the difference between the patient's diastolic blood pressure and compartment pressures).
The most common symptom of compartment syndrome in the extremities is intense pain. However, compartment syndrome can be difficult to diagnose in children and patients who are comatose, nonverbal, and/or mentally compromised because they may not be able to properly express their level of pain. Additionally, in compartment syndrome of the foot, pain on passive extension of the toes may or may not be present, and swelling and absence of the dorsalis pedis pulse may be expected findings with extensive trauma to the foot, making the clinical diagnosis even more difficult. Thus, for patients with equivocal findings on physical exam, foot compartment pressures should be measured in order to confirm the diagnosis. There are 8 compartments in the foot: lateral, medial, central, and 4 interosseous. The lateral compartment
contains the abductor digiti minimi and flexor digiti minimi brevis, and is measured by directing the needle 1cm medial and plantar under the midshaft of the 5th metatarsal. The medial compartment contains the abductor hallicus and flexor hallicus brevis, and is measured by directing the needle lateral and plantar under the base of the first metatarsal. The central compartment contains the oblique head of the adductor hallucis, and is measured through the same approach as the medial compartment after advancing the needle more deeply. The 4 interosseous compartments entail the 2nd, 3rd, and 4th web spaces, and can be measured by directing the needle plantar into each respective dorsal webspace.
Ojika et al. performed a systematic review on foot compartment syndrome. They found that the most common cause of foot compartment syndrome was crush injury to the foot, and that diagnosis was mostly made through a combination of clinical findings and compartment pressure measurements.
Badhe et al. reported 4 cases where competent sensate patients developed compartment syndromes without any significant pain. They found that pain is not a reliable clinical indicator for underlying compartment syndrome, so in a competent sensate patient, the absence of pain does not exclude compartment syndrome. They concluded that a high index of clinical suspicion must prevail in association with either continuous compartment pressure monitoring or frequent repeated documented clinical examination with a low threshold for pressure measurement.
Flynn et al. looked at the diagnosis and outcome of acute traumatic compartment syndrome of the leg in children. They found that a delay in diagnosis may occur because acute traumatic compartment syndrome manifests itself more slowly in children or because the diagnosis is harder to establish in this age group. They state that the results of the present study should raise awareness of late presentation and the importance of vigilance for developing compartment syndrome in the early days after injury.
Figures A and B are lateral and Harris radiographs of the foot demonstrating a calcaneus fracture. Figure C is a cross-sectional image of the foot. Illustration A is an image depicting the compartments of the foot.
Incorrect Answers:
compartment. Additionally, a Δp < 30mmHg (not > 30mmHg) is considered abnormal.

OrthoCash 2020
A 35-year-old female presents to the emergency room after a motor vehicle collision where her leg was pinned under the car for over 30 minutes. A clinical photo and radiographs are shown. Which of the following is the most accurate way to diagnose compartment syndrome?

surgeon's palpation of the leg compartments
paresthesias in her foot
diastolic blood pressure minus intra-compartmental pressure is less than 30 mmHg
diastolic blood pressure minus intra-compartmental pressure is greater than 30 mmHg
intra-compartmental pressure measurement of 25 mmHg Corrent answer: 3
The clinical picture is consistent with compartment syndrome. The most accurate way to make the diagnosis is to measure the difference between the diastolic blood pressure and intracompartmental pressure (delta p).
In a prospective study of 116 patients with tibial diaphyseal fractures, McQueen et al found that the use of a differential pressure of 30 mmHg as a threshold for fasciotomy led to no missed cases of acute compartment syndrome. They recommended that a fasciotomy should be performed if the differential pressure level drops to under 30 mmHg.
The cited study by Kakar et al found the intraoperative DBP is significantly lower than the preoperative DBP in patient undergoing IM nailing for tibia shaft
fractures. Therefore, they emphasize that the surgeon should recognize that intraoperative DeltaP may be lower than DeltaP once the patient is awakened in deciding whether to perform a fasciotomy versus awaken the patient and perform serial examinations and or compartment pressure measurements.
An absolute intra-compartmental value greater than 30 to 45mmHg can also be used to make the diagnosis of compartment syndrome, but is more controversial than the delta p according to Kakar and Amendola.
OrthoCash 2020
What is the most common mode of failure of the lateral ulnar collateral ligament associated with an elbow dislocation?
ligament avulsion off the humeral origin
ligament avulsion off the ulnar insertion
midsubstance rupture
bony avulsion of the humeral origin
combined proximal and distal ligament avulsions Corrent answer: 1
The lateral ulnar collateral ligament (LUCL) is often injured with elbow dislocations, and is most commonly injured at the proximal origin.
McKee noted that in 62 consecutive operative elbow dislocations and fracture/dislocations, the LUCL was ruptured in all of the patients, proximally in 32, bony avulsion proximally in 5, midsubstance rupture in 18, ulnar detachment in 3, ulnar bony avulsion in only 1, and combined patterns in 3.
Pugh et al established a standard protocol to treat elbow fracture dislocations (terrible triad) which includes coronoid repair, radial head repair/replacement, LUCL repair, and MCL and/or external fixation as needed.
OrthoCash 2020
A 24-year-old male sustains the injury seen in Figure A after being thrown from a motorcycle at a high speed. Which of the following fixation methods has been shown to be the most stable fixation construct for this injury?

Posterior bridge plating and anterior ring external fixation
Percutaneous iliosacral screw and anterior ring external fixation
Percutaneous iliosacral screw and anterior ring internal fixation
Transiliac screw
Two percutaneous iliosacral screws Corrent answer: 3
Figure A shows an APC III injury, which is a rotationally and vertically unstable injury, with damage to the anterior ring, pelvic floor, and posterior ligamentous stabilizing structures.
The referenced study by Sagi et al found that biomechanically, a percutaneous iliosacral screw and anterior ring internal fixation was the most stable construct. In addition, he found no biomechanical support for addition of a second iliosacral screw.
OrthoCash 2020
A 33-year-old male patient presents with a comminuted open tibia fracture after involvement in a motor vehicle crash. He has a history of smoking but is otherwise healthy. He is given antibiotics, and taken immediately for irrigation and debridement, followed by an un-reamed stainless steel intramedullary nail. Due to bone loss there is a non-circumferential cortical defect measuring 12 mm at the fracture site. All of the following factors in this patient's history and presentation increase his risk for adverse outcome EXCEPT:
High-energy mechanism of injury
Use of un-reamed nail
Implant material
Fracture gap
History of smoking Corrent answer: 2
Of the factors listed only the use of an un-reamed intramedullary nail for an open tibia fracture has not been shown to increase the risk of adverse outcome or need for reoperation.
The treatment of open tibia fractures with intramedullary nailing can be complicated by many factors. High energy mechanism of injury, use of a stainless steel nail, residual fracture gap greater than 1 cm, and a history of smoking have all been shown to increase the risk of adverse outcome. The use of reamed and un-reamed nails for open tibia fractures have been studied, and no significant difference in outcome has been found.
Schemitsch et al. present data from a prospective randomized trial of tibia fractures treated with reamed or unreamed intrameduallry nails. They found no difference in risk of adverse outcome between reamed and un-reamed nails in open tibia fractures. They did, however, find an increased risk of adverse outcomes in high-energy mechanisms, use of stainless steel (versus titanium) rods, and a residual fracture gap of greater than 1 cm. They comment that their data did not show a significant increase in risk due to history of smoking, but cite other studies that have demonstrated such a relationship.
Bhandari et al. present data from a prospective randomized study of patients with tibia fractures randomized to reamed or un-reamed tibial nails. For closed fractures they found a lower rate of primary events (most commonly need for dynamization) in the reamed group. However, they found no difference in outcomes for either technique in open fractures.
Incorrect answers:
OrthoCash 2020
Following antegrade intramedullary nailing of a femoral shaft fracture, the complication shown in Figure A occurs. Which of the following errors most likely resulted in this complication?

Applying external rotation torque on the proximal femur after placing proximal interlocking screws
Excessive interfragmentary compression of the fracture site prior to placing proximal interlocking screws
Using too anterior a starting point for a piriformis-entry point nail
Inserting a trochanteric-entry point nail through the piriformis fossa
Inserting a right femoral nail into the left femur Corrent answer: 3
Using a piriformis nail, a starting point that is too anterior will result in iatrogenic fracture ("bursting") of the proximal femur.
Antegrade nailing achieves fixation via 3-point fixation. In the sagittal plane, because of anterior sagittal bow, this is achieved at distal anterior cortex, middle posterior cortex (apex of curvature) and proximal anterior cortex. In the coronal plane, because of the lateral bow, this is achieved at the lateral distal femur, middle medial femur (apex of curvature), and proximal lateral femur (greater trochanter). Piriformis nails have a single sagittal bow.
Trochanteric nails are bowed in 2 planes, necessitating a twisting motion during insertion to negotiate both bows.
Papadakis et al. performed an experimental study on 18 cadaveric femora. Anterior bursting was found in 56% of nails placed too anteriorly. Bursting was not seen in nails placed through a more posterior entry point. They emphasize the location of the entry point when performing antegrade nailing.
Johnson et al. reviewed the biomechanical factors affecting fracture stability
and femoral bursting. They found that position of the starting hole was most important. Anterior displacement by >6mm led to high hoop stresses and bursting of the anterior cortex. This is important as an eccentrically reamed cortex may be difficult to recover from. They recommend either selecting a smaller diameter nail or overreaming by 1-2mm as a solution.
Figure A shows a fracture split of the proximal femur (left, without magnification; right, close-up). Illustration A shows anterior cortex pressures exceeding 100kPa for too-anterior entry points.
Incorrect Answers:
Wrong-side placement of a trochanteric entry nail would lead to varus malalignment at the fracture site, more so than placing a piriformis nail through the greater trochanter.

OrthoCash 2020
A 30-year-old male sustains a brachial plexus injury as the result of a motor vehicle collision. Palsy of which of the following muscles would not be expected with this injury if the injury was postganglionic in nature?
Rhomboid major
Extensor carpi radialis longus
Biceps brachii
Deltoid
Brachioradialis
A brachial plexus injury would involve all of the upper extremity muscles as well as most of the periscapular muscles. Complete plexus palsies are rare, and are often associated with scapulothoracic dissociation or other high-energy injuries.
Preganglionic injuries often involve the cervical paraspinal musculature as well as a complete plexus injury. EMG evidence of intact signals in the serratus anterior (long thoracic nerve) and rhomboids (dorsal scapular nerve) are suggestive of a postganglionic lesion/injury.
Tubbs et al. reported on the surgical anatomy of the dorsal scapular nerve in a cadaver study. They found that the nerve came off the C5 nerve root in 95%, ran 2.5cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle, and was intertwined with the dorsal scapular artery in all specimens.
Balakrishnan et al reported on the comparison of clinical exam and EMG in predicting site of lesions in brachial plexus injuries. The combination of EMG and exam localized the nerve injury in 80%, while the paraspinal EMG was the most sensitive solitary examination method (67%).
Illustration A shows a diagram of the brachial plexus. Incorrect Answers:
5: These muscles are all innervated by nerves that come from the brachial
plexus, and would be affected with a postganglionic injury.

OrthoCash 2020
A 40-year-old male sustains a fall from a height. He sustains the isolated injury shown in the radiograph and CT images seen in Figures A through C. Surgery is planned. Which of the following constructs is the most appropriate definitive fixation for this injury?

Lateral locked plating
Medial bridge plating
Medial buttress plate
Medial lag screw with washers
External fixation
This patient has a medial tibial plateau fracture. Medial buttress plating (MBP) is indicated.
Medial tibial plateau fractures (Schatzker IV, Hohl and Moore II) may represent fracture dislocations of the knee. Neurovascular injuries must be excluded. In these instances, the medial fragment represents the stable fragment, and the rest of the tibia is the fractured fragment, with the entire leg acting as the lever arm.
Berkson et al. reviewed high energy tibial plateau fractures. Medial fractures may be treated with a medial plate or external fixation. Open reduction may be necessary because of fracture line obliquity and propensity of the medial plateau to shorten and rotate in the sagittal plane. Meniscal injuries should be repaired and avulsed cruciates fixed early. Collateral ligaments should be reconstructed after obtaining bone healing and range of motion.
Ratcliff et al. compared the stability of lateral locked plates and medial buttress plates in a cadaver model. They found that the medial buttress plate had greater fixation strength/failure force (4136N) compared with the lateral locking plate (2895N), although maximum cyclic displacement and residual displacement results were not different. They concluded that for vertically
orientated medial tibial plateau fractures, medial buttress plates were more stable.
Figure A is a radiograph showing a medial tibial plateau fracture extending across the tibial eminence. This is also classified as a Hohl and Moore Type II fracture. Figures B and C are coronal and axial CT scan images confirming the medial tibial plateau fracture and excluding a bicondylar fracture. Illustration A shows a medial tibial plateau fracture fixed with a medial buttress plate (cadaveric model with fibula removed). Illustration B shows the Hohl and Moore Type II fracture involving the entire condyle.
Incorrect Answers:

OrthoCash 2020
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?

Weakness of hip flexion
Weakness of ankle dorsiflexion
Numbness of the medial thigh
Numbness of the lateral thigh
Numbness of the perineum Corrent answer: 4
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:
OrthoCash 2020
What would be the most appropriate surgical indication for transferring fascicles of the ulnar nerve to the motor nerve of the biceps and fascicles of the median nerve to the motor nerve of the brachialis?
C8 - T1 nerve root avulsion 3 months ago
C5 - C6 nerve root avulsion 2 months ago
Upper brachial plexus palsy 22 months ago
Medial and posterior cord injury from gunshot wound 2 months ago
C6 ASIA A spinal cord injury Corrent answer: 2
Transfer of fascicles from (1) ulnar nerve to the nerve to the biceps and (2) median nerve to the motor nerve of the brachialis would be appropriate in the
treatment of an acute (<3-6 months) upper brachial plexus palsy.
Upper trunk injury (C5, C6) often results from the avulsion of both the C5 and C6 nerve roots. Injuries of this nature usually result from a downward force on the shoulder with lateral bending of the cervical spine in the opposite direction. This results in what is commonly called an Erb-Duchenne palsy. Patients often present with a flail shoulder and loss of elbow flexion. Other common treatments for C5 and C6 root avulsion include neurotization of the musculocutaneous (MSC) nerve by the spinal accessory (SA) or intercostal nerve, and neurotization of the supra-scapular nerve by the SA.
Liverneaux et al. looked at short term results of (1) ulnar nerve fascicle transfer to the nerve to the biceps and (2) fascicle of the median nerve to the motor branch to the brachialis in 15 patients with acute C5 - C6 nerve root avulsion injuries. Grade 4 elbow flexion was restored in each of the 10 patients. There was no secondary deficit in grip strength or sensation.They concluded that this double nerve transfer technique will likely reduce the need for secondary procedures to augment elbow flexion.
Teboul et al. reviewed thirty-two patients with an upper nerve-root brachial plexus injury that underwent ulnar nerve fascicle transfer to the nerve of biceps to restore elbow flexion. After the nerve transfer, twenty-four patients achieved grade 3 elbow flexion strength or better. They note that this procedure will spare the C5 nerve root and other nerves for grafting or transfer elsewhere.
Illustration A shows harvesting of an ulnar nerve fascicle for transfer. Illustration B shows transfer of the fascicle of the ulnar nerve to the motor nerve of the biceps.
Incorrect Answers:
sensory quadriplegia. Nerve transfers using the ulnar nerve (C8-T1) would also be redundant as this nerve would be non-functional in this patient.

OrthoCash 2020
A 31-year-old female presents to the trauma bay following a motorcycle crash. Her blood pressure is 95/70 mmHg, heart rate is 115 bpm. Lactate measured in the trauma bay is 10 mmol/L. She has multiple rib fractures, pulmonary contusions, and a positive FAST exam requiring immediate exploratory laparotomy. After laparotomy her lacate remains unchanged. She has a closed right femur fracture and an open right tibia fracture as seen in Figures A and B. Besides antibiotics and thorough irrigation and debridement, which of the following would be an appropriate step in the immediate management of her fractures?

Reamed intramedullary nailing of the tibia and femur
Un-reamed intramedullary nailing of the tibia, and reamed intramedullary nailing of the femur
Reamed intramedullary nail of the tibia, and un-reamed intramedullary nail
of the femur
Posterior slab splint of the tibia, and 10 lbs skeletal traction of the femur
External fixation of the tibia and femur Corrent answer: 5
This patient is suffering from multiple injuries and has evidence of chest injury and incomplete resuscitation. The immediate treatment of her fractures should be external fixation for both the tibia and the femur.
For polytraumatized patients with multiple injuries including extremity fractures, damage control orthopaedics dictates that long bone fractures should be temporarily stabilized. Either inadequate stabilization, or early total care, such as a reamed or unreamed nails, can exacerbate the patient's condition and increase the risk of a second-hit phenomenon. For this patient with pulmonary contusions and continued elevation of lactate indicating end-organ hypoperfusion her extremities should have staged treatment according to damage control principles.
Morshed et al. present a retrospective review of polytraumatized patients with femur fractures and compared outcomes based on the time frame in which their fractures were definitively treated. They found delaying treatment at least 12 hours to allow appropriate resuscitation and treatment of other traumatic injuries led to a decrease in mortality of 50%. Patients with intra-abdominal injuries benefited most from staged treatment of the extremities.
Figure A is a radiograph showing a closed right femur fracture. Figure B is a radiograph of an open right tibia fracture.
Incorrect answers:
OrthoCash 2020
A 68-year-old woman undergoes a hemiarthroplasty for a proximal humerus fracture through a deltopectoral approach. What
range of motion exercise should not be utilized in the immediate postoperative period due to concerns about lesser tuberosity fixation?
Pendulums
Passive internal rotation of the shoulder to the plane of the body
Active forearm supination
Passive external rotation of the shoulder past 30 degrees
Passive forward flexin of the shoulder to 90 degrees Corrent answer: 4
Frankle et al found that passive external rotation of the shoulder placed the most stress on the lesser tuberosity fixation. The subscapularis tendon inserts on the lesser tuberosity and is the deforming force when placed under tension during external rotation. They also found that non-anatomic tuberosity reduction of 4-part proximal humerus fractures treated with hemiarthroplasty increased torque and impaired external rotation kinematics.
OrthoCash 2020
A 72-year-old female sustains a displaced intracapsular femoral neck fracture. Which of the following is TRUE regarding the long term differences between possible treatment options for this injury?
Patients undergoing total hip arthroplasty are more likely to experience persistent pain than those undergoing internal fixation
Patients undergoing total hip arthroplasty are less likely to require reoperation than those undergoing internal fixation
There is no difference in functional outcome scores between internal fixation and total hip arthroplasty
Patients undergoing internal fixation perform activities of daily living better than those undergoing total hip arthroplasty
Mortality rates are higher following total hip arthroplasty than internal fixation
Elderly patients with femoral neck fractures (FNF) undergoing total hip arthroplasty (THA) are less likely to require reoperation than those undergoing internal fixation.
Intracapsular FNF are common in elderly patients after a fall from standing height. Treatment depends on physiological age and displacement (Garden's classification). For displaced fractures, physiologically young patients are treated with internal fixation while physiologically old patients are treated with
either hemiarthroplasty (debilitated, less active patients) or THA (more active patients, those with acetabular disease or preexisting inflammatory arthritis).
Chammout et al. retrospectively compared the long term (17 years) results of THA (cemented both component) and ORIF (2 cannulated screws) in elderly patients (>65 years). They found no difference in mortality. But hip scores were higher and pain was better in the THA group, while reoperation rates were higher in the ORIF group. Walking speed was initially faster in the THA group, but later did not differ between groups. They recommend THA for elderly patients with displaced FNF.
Rogmark et al. prospectively compared closed reduction and internal fixation (CRIF) with arthroplasty (combining hemiarthroplasty and THA) at 2 years in elderly patients (>70 years). Failure rates were higher, pain was worse, and walking was more impaired after CRIF. They recommend arthroplasty for patients >70 with FNF.
Incorrect Answers:
OrthoCash 2020
A polytrauma patient underwent the following procedures: (1) statically locked intramedullary nailing for a right femoral shaft fracture; (2) open reduction with plate-and-screw fixation [ORIF] for a right simple distal fibula fracture; (3) ORIF right middle third radius and ulna fracture; and (4) ORIF left humeral shaft fracture. What is the appropriate weightbearing status for this patient?
Weight bearing as tolerated in all extremities
Early protected weight bearing right lower extremity in walking cast, weight bearing as tolerated left upper extremity, non-weight bearing right forearm
Weight bearing as tolerated in bilateral lower extremities and right upper extremity, non-weight bearing left upper extremity
Non-weight bearing bilateral upper extremities and right lower extremity
Non-weight bearing right upper and lower extremities, weight bearing as tolerated left upper and lower extremities without walking cast
The standard postoperative weightbearing for locked medullary nailing for femoral shaft fractures and humeral shaft fractures is weight bearing as tolerated (WBAT). Simple ORIF ankle fractures may be managed with early protected weight bearing. ORIF right middle third radius and ulna fracture should be managed with a period of non-weight bearing due to risk of secondary displacement of the fracture.
Tingstad et al. examined the effect of immediate weightbearing on plated fractures of the humeral shaft. They reported that immediate weightbearing on humeral shaft fractures, treated with plating and full weightbearing, did not have any negative effect on the union or malunion rates.
Brumback et al. evaluated the feasibility, safety and efficacy of immediate weightbearing after treatment of femoral shaft fractures with statically locked IM nail. Using biomechanical and clinical data, they showed that all fractures united with no loss of fixation or hardware failure.
Starkweather et al. retrospectively assessed the complications and loss of reduction in patients who bore weight in a short leg cast within 15 days after surgical repair of acute unilateral closed ankle fractures. Of the 81 ankle fracture radiographs, 80 (98.8%) showed no displacement in fracture reduction on the final follow-up examination. These results suggest early protected weightbearing may be safe.
Incorrect Answers:
OrthoCash 2020
A 22-year-old female falls off the back of a motorcycle and sustains the injury in Figure A. She is hemodynamically unstable and massive transfusion protocol is activated. What is the correct ratio of transfusion of packed red blood cells, platelets and plasma?

Question 40

Figure 40 shows the radiograph of a 16-year-old wrestler who injured his elbow when he was thrown to the mat by his opponent. Closed reduction is readily accomplished, and the elbow seems stable. Management should now consist of application of a splint for

Explanation

DISCUSSION: Flexion contractures are the most common complication of elbow dislocations. About 15% of patients lose more than 30 degrees of flexion. The risk of contracture is proportional to the duration of immobilization. Elbows should be moved within the first few days after reduction. The splinting is for comfort and protection only while the pain subsides.
REFERENCES: Mehlhoff TL, Noble PC, Bennett JB, Tullos HS: Simple dislocation of the elbow in the adult: Results after closed treatment. J Bone Joint Surg Am 1988;70:244-249.
Linscheid RL, O’Driscoll SW: Elbow dislocations, in Morrey BF (ed): The Elbow and Its Disorders, ed 2. Philadelphia, PA, WB Saunders, 1993, pp 441-452.
O’Driscoll SW, Jupiter JB, King GJ, Hotchkiss RN, Morrey BF: The unstable elbow. Instr Course Lect 2001;50:89-102.
Ross G, McDevitt ER, Chronister R, Ove PN: Treatment of simple elbow dislocation using an immediate motion protocol. Am J Sports Med 1999;27:308-311.

Question 41

Which of the following factors is most likely to predispose a patient to dislocation of the patellar component following total knee arthoplasty?

Explanation

The experimental data for this answer came from Anouchi et al The Effects of Axial Rotational Alignment of the Femoral Component on Knee Stability and Patellar Tracking in Total Knee Arthroplasty Demonstrated on Autopsy Specimens. This study looked at knee stability, patellar tracking, and patellofemoral contact points with the femoral component positioned in 5 degrees internal, 5 degrees external, and neutral alignment in relation to the posterior femoral condyles. Total knee arthroplasty was performed on four cadavaric specimens without lateral release.
Internally rotating the femoral component produced abnormal laxity seen at 30, 60, and 90 degrees of flexion. There was no gapping noted in the neutral or externally rotated specimens.
The normal pattern for patellar tracking was a gentle curve with maximal deflection at 15 and 60 degrees of flexion. The maximal medial displacement were lowest for the externally rotated specimens.
Although contact areas could not be quantitatively measured accurately, the contact areas were more evenly distributed between the medial and lateral sides of the patella in the externally rotated specimens than they were in either the internally rotated or neutral specimens.
You have to be careful interpreting this data at least in reference to knee stability. In this study a perpendicular tibial cut was made. The normal tibia has a 30 degree varus slope and thus more bone is resected from the lateral surface. External rotation of the femoral component compensates for this.
No tests were done with lateral placement of the femoral component or medial placement of the patellar component.

Question 42

A 10-year-old boy reports heel pain with sporting activities. An examination demonstrates gastrocnemius contracture and tenderness at the calcaneal apophysis. Radiographs are unremarkable. What is the best next step?

Explanation

DISCUSSION
Sever disease, or calcaneal apophysitis, is best treated with activity modification that includes rest, restriction from sports and running, and Achilles tendon stretching exercises. The diagnosis is clinical (rendering MRI study unnecessary) and the course is usually self-limited, obviating the need for surgery. Occasionally, children with severe symptoms may benefit from a short period of cast or fracture brace immobilization.
RECOMMENDED READINGS
Sullivan RJ. Adolescent foot and ankle conditions. In: Pinzur MD, ED. Orthopaedic Knowledge Update: Foot and Ankle 4. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2008:47-55.
Feldman DS. Osteochondrosis. In: Spivak JM, Di Cesare PE, Feldman Ds, et al, eds. Orthopaedic: A Study Guide. New York, NY: McGraw-Hill; 1999:765-766.

Question 43

A 32-year-old man sustained an injury to the right thumb metacarpophalangeal (MP) joint ulnar collateral ligament (UCL) and is undergoing surgical repair (Figure 1). What structure in the clinical photograph is blocking reduction of the ulnar collateral ligament?

Explanation

EXPLANATION:
When the thumb MP UCL is torn from the proximal phalanx, the distal stump can be displaced superficial to the adductor aponeurosis, known as a Stener lesion. The adductor aponeurosis effectively blocks reduction of the ligament to the normal attachment site. The EPB and EPL tendons are dorsal to the UCL, and the ulnar sesamoid bone/volar plate are in a volar position in relation to the UCL. The dorsal capsule would also not block reduction of the UCL due to it's anatomic location. The other responses do not block the UCL with this type of injury.

Question 44

In the treatment of rheumatoid arthritis, which medication is an antagonist of tumor necrosis factor-alpha?

Explanation

Etanercept is a biochemically designed tumor necrosis factor receptor immunoglobulin G fusion protein, which binds to TNF-alpha and is thus a TNF-alpha antagonist.
TNF-alpha is considered to be one of the major cytokines involved in rheumatoid arthritis pathology. As a result, many biologic agents used to treat rheumatoid arthritis (RA) are manufactured to block TNF-alpha or its receptors. This has been shown to reduce inflammation and stop disease progression. In the USA, Etanercept is approved to treat rheumatoid arthritis, juvenile rheumatoid arthritis and psoriatic arthritis, plaque psoriasis and ankylosing spondylitis. The route of administration is subcutaneous.
Bongartz et al. used a randomized control trial to asses the risk of infection and malignancy rates in RA treated with TNF-alpha antagonist. Overall, patients with RA appear to have an approximately 2-fold increased risk of serious infection compared to the general population and non-RA controls, irrespective of TNF-alpha antagonist use. The pooled odds ratio for malignancy was 3.3 (95% confidence interval [CI], 1.2-

Question 45

Radiographs of a pediatric patient reveal a suspected osteosarcoma of the distal femur. Additional staging studies should consist of

Explanation

DISCUSSION: CT of the abdomen and pelvis is not part of the staging of osteosarcoma. Staging studies should consist of CT of the chest, radiographs of the chest and primary tumor, MRI of the primary tumor, and a bone scan. The MRI should be obtained prior to the biopsy.
REFERENCE: O’Reilly R, Link M, Fletcher B, et al: NCCN pediatric osteosarcoma practice guidelines: The National Comprehensive Cancer Network. Oncology (Huntingt) 1996;10:1799-1806, 1812.

Question 46

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

Explanation

The definition of brachial neuritis or Parsonage-Turner syndrome is a rare disorder of unknown etiology that causes pain or weakness of the shoulder and upper extremity. The loss of active motion excludes cervical C6-7 radiculopathy and impingement. A normal MRI scan and full passive motion exclude a rotator cuff tear and adhesive capsulitis, respectively.

Question 47

Glenohumeral disarticulation often leads to which of the following changes?

Explanation

Postural abnormalities are common after high upper extremity amputation. Normally the weight of the upper extremity and the shoulder girdle muscles keep the shoulder balanced. When the arm is amputated and the scapula remains, the shoulder girdle muscles are unopposed, resulting in upward movement often called "hiking" of the shoulder girdle. In a growing child, removal of the entire upper limb can result in scoliosis of the spine due to muscle imbalance. Abnormal shoulder elevation can often be minimized by corrective exercises and wearing a shoulder prosthesis.

Question 48

A 13-year-old quarterback feels a “pop” in his knee while being tackled. Radiographs of the knee and results of a Lachman’s test are normal. Examination reveals tenderness over the distal femoral physis. To help confirm the diagnosis, management should first include

Explanation

Injuries involving the distal femoral epiphysis cartilage plate are fairly common. Appropriate management should include a complete knee exam with a standard series of X-rays. Of particular importance is to notice any varus or valgus deformity. Stephens et al. (JBJS 1974:56A) measured varus and valgus deformities clinically and roentgenographically. A varus or valgus deformity greater than 3 degrees as compared with the uninjured side was considered clinically significant. Such deformities are highly suggestive of a physeal injury. A MRI may show the injury, but is expensive as is an arthroscopy or examination under anesthesia.

Question 49

A 72-year-old man was involved in an automobile accident 4 weeks ago. Initially he noted pain about his nondominant left shoulder, which resolved within a few weeks after the accident. He now describes trouble with gripping and carrying items in his left hand. Radiographs are shown in Figures 20a through 20c. His signs and symptoms are the result of injury to which of the following ligaments?

Explanation

DISCUSSION: The radiographs reveal a gap between the scaphoid and lunate bones, indicative of disruption of the scapholunate ligament complex. The three components of the complex are the dorsal scapholunate ligament, the volar (or palmar) scapholunate ligament, and the proximal fibrocartilaginous membrane, listed in decreasing yield strength. Disruption of the stout dorsal interosseous ligament is required for scapholunate dissociation to occur.
REFERENCES: Berger RA: The ligaments of the wrist: A current overview of anatomy with considerations of their potential functions. Hand Clin 1997;13:63-82.
Cohen MS, Taleisnik J: Direct ligamentous repair of scapholunate dissociation with capsulodesis augmentation. Tech Hand Up Extrem Surg 1998;2:18-24.

Question 50

Figures 30a and 30b are the radiographs of a 61-year-old man with diabetes who fell from a ladder and sustained an isolated closed fracture. After realignment and splint application, what is the most appropriate next step in management?

Explanation

The patient has sustained a high-energy severely comminuted AO/OTA C2 fracture of the distal tibia. This injury is notably fraught with soft-tissue complications that can lead to disastrous clinical results. In general, a staged protocol is now preferred in an effort to avoid these complications and has shown substantial decreases in infection rates and wound healing problems. A CT scan is certainly appropriate for preoperative planning but should be obtained after frame application because the indirect reduction that is achieved improves one's ability to understand the fracture characteristics and morphology. Hybrid external fixation has fallen out of favor because of its limited biomechanic rigidity and clinical results. Open reduction and
internal fixation in the acute phase (6 to 8 hours) or sub-acute phase (2 to 3 days) is difficult.

Question 51

Figure 46 shows the MRI scan of a patient who has a mass in the calf that has been fluctuating in size. Radiographs are negative. Which of the following procedures will most quickly aid in confirming the diagnosis?

Explanation

DISCUSSION: The bright signal on the T2-weighted MRI scan suggests fluid. The multiloculated appearance in proximity to the proximal tibiofibular joint suggests that the most likely diagnosis is a ganglion. They typically increase and decrease in size and can be diagnosed by the classic gelatinous fluid obtained through needle aspiration.
REFERENCES: Bianchi S, Abdelwahab IF, Kenan S, Zwass A, Ricci G, Palomba G: Intramuscular ganglia arising from the superior tibiofibular joint: CT and MR evaluation. Skeletal Radiol 1995;24:253-256.
Feldman F, Singson RD, Staron RB: Magnetic resonance imaging of para-articular and ectopic ganglia. Skeletal Radiol 1989;18:353-358.

Question 52

preservation of the radioscaphocapitate ligament, the most radial of the palmar extrinsic ligaments, which prevents ulnar subluxation after proximal row carpectomy.

Explanation

A 37-year-old patient with type I diabetes mellitus has a flexor tenosynovitis of the thumb flexor tendon sheath following a kitchen knife puncture wound to the volar aspect of the thumb. Left unattended, this infection will likely first spread proximally creating an abscess in which of the following spaces of the palm?
Central space
Hypothenar space
Carpal tunnel
Posterior adductor space
Thenar space CORRECT ANSWER: 5
Flexor tenosynovitis of the thumb flexor tendon sheath can spread proximally and form an abscess within the thenar space of the palm. The flexor pollicis longus tendon does not pass through the central space of the palm or the hypothenar space of the palm. The flexor pollicis longus tendon does pass through the carpal tunnel, but this is not a palmar space. The three palmar spaces include the hypothenar space, the thenar space, and the central space. The posterior adductor space would likely only be involved secondarily after spread from a thenar space infection.
New painful paresthesias near the site of the incision after an ulnar nerve transposition is the result of injury to what nerve?
Medial antebrachial cutaneous
Lateral antebrachial cutaneous
Posterior antebrachial cutaneous
Medial brachial cutaneous
Dorsal antebrachial cutaneous
Branches of the medial antebrachial cutaneous nerve can often be identified during routine ulnar nerve surgery crossing the medial aspect of the elbow. It should be preserved to avoid development of painful paresthesias.
A 21-year-old man who was injured in a snowboarding accident 18 months ago now reports wrist pain. An MRI scan is shown in Figure

Question 53

A 7-year-old male is struck by a motor vehicle while crossing the street and suffers an open tibia fracture with a crush injury of the ipsilateral foot. After multiple attempts at limb salvage, the family and treating surgeon elect to proceed with a knee disarticulation. What complication of pediatric amputations is avoided with a knee disarticulation as opposed to a transtibial amputation?

Explanation

DISCUSSION: Bone overgrowth is a poorly understood phenomenon in which the bone end undergoes disorganized appositional growth following amputation in a skeletally immature patient. Overgrowth is the most common complication following transosseous amputation in pediatric patients.
Krajbich reviews the management of pediatric patients with lower-limb deficiences and amputations. He advocates disarticulation as opposed to transosseous amputation when possible as bone overgrowth has not been observed in bone ends covered by articular cartilage.
O'neal et al retrospectively reviewed their rates of surgical revision for bone overgrowth in pediatric and adolescent amputees. The highest rates of revision were seen with metaphyseal-level amputations (50%) and with traumatic amputations (43%).
Benevenia et al reviewed their rates of overgrowth in skeletally immature transosseous amputees using an autogenous epiphyseal transplant from the amputated limb to cap the medullary canal. They found that only 1 of 10 patients undergoing amputation with this technique had complications due to bone overgrowth, compared with 6 of 7 patients undergoing traditional transosseous amputation.
Illustration A is a clinical photo of bone overgrowth eroding through the soft tissue in a transhumeral amputee. Illustration B demonstrates the radiographic appearance of bone overgrowth in a transtibial amputation.
Incorrect Answers:

Question 54

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

Explanation

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

Question 55

A 12-year-old boy has a head-on head collision while playing soccer. He had no loss of consciousness but has persistent headaches for 2 weeks. The patient is now back to school and has no headaches. What is the best next step?

Explanation

Mild traumatic brain injury is common in the adolescent child. Neuropsychological examination is widely used but, in this case, the patient is asymptomatic and has no baseline testing. There is a limited role for MRI in the recovery process of concussions. Furthermore, higher levels of physical/cognitive activity should be avoided due to their potential to increase total recovery time. In this scenario, a graduated return to activity is most appropriate thus, the next appropriate step is to start light aerobic activity.

Question 56

A 1-year-old infant has the hand deformities shown in Figure 40. What pathologic process is the most likely cause of these deformities?

Explanation

DISCUSSION: Streeter’s dysplasia is clearly related to rupture of the amnion in utero and is now most commonly referred to as premature amnion rupture sequence. The deformities arise from amniotic bands that wrap about protruding parts and from uterine packing because of the accompanying oligohydramnios. Clubfoot can develop as a result of the latter mechanism. Three limb involvement is most commonly seen, along with syndactyly. Treatment involves resection of bands and Z-plasty of skin. The disease is not genetic and has not been related to teratogen exposure or to iatrogenic influences such as amniocentesis. Developmental field disruption is not seen in this disease, and the growth potential of the involved parts is normal unless neurovascular disruption has arisen from band formation.
REFERENCE: Foulkes GD, Reinker K: Congenital constriction band syndrome: A seventy-year experience. J Pediatr Orthop 1994;14:242-248.

Question 57

Initial repair of the large U-shaped rotator cuff tear shown in Figure 12 consists of closing the tear side-to-side to take advantage of margin convergence. The most significant biomechanical consequence of this repair step results in

Explanation

DISCUSSION: Margin convergence refers to the phenomenon that occurs with side-to-side closure of large U- or L-shaped rotator cuff tears in which the free margin of the tear converges toward the greater tuberosity as the side-to-side tear progresses. The creation of the converged cuff margin creates decreased strain in the free margin of the repaired cuff, resulting in a decreased strain in the repair sutures. While the size of the humeral head defect is made smaller with side-to-side closure, biomechanically, this is less significant. The mild increase in thickness of the repair at the side-to-side margin is less important than a reduction in stress in the repaired tissue. Stress in the crescent cable region of the cuff actually increases and becomes more physiologic in transmitting force from the cuff to the greater tuberosity.
REFERENCES: Burkhart SS: A stepwise approach to arthroscopic rotator cuff repair based on biomechanical principles. Arthroscopy 2000;16:82-90.
Burkhart SS, Athanasiou KA, Wirth MA: Margin convergence: A method of reducing strain in massive rotator cuff tears. Arthroscopy 1996;12:335-338.

Question 58

A patient has pain 2 years after undergoing a metal-on-metal (MOM) left total hip arthroplasty (THA). Which test(s) best correlate with a prognosis if this patient is having a reaction to metal debris?

Explanation

Painful MOM THA and taper corrosion can cause substantial damage to a patient's hip if left untreated. In this case, the workup for a painful MOM THA starts the same as a workup for a painful metal-on-polyethylene bearing couple. Infection must be ruled out in every case with a set of inflammatory markers. If these markers are remotely elevated, this is an indication for joint aspiration. In patients with metal debris, the pathology report often indicates too many cells to count or cellular debris. Metal ion levels do not seem to correlate with prognosis. There are well-functioning patients with high ion levels and poor-functioning patients with low ion levels. Advanced imaging with MARS MRI to evaluate for peritrochanteric fluid collection, a soft-tissue mass, or synovial/capsular hypertrophy will reveal signs of a metal reaction that indicate the need for a revision discussion. A CT scan can show more advanced bony destruction as an indicator of poor prognosis. These films can be used to determine the need for a structural graft or augments for reconstruction of bone loss attributable to metal debris.

Question 59

An 82-year-old osteoporotic woman undergoes total hip arthroplasty for osteoarthritis. During implant trialing, a crack is heard. Intraoperative fluoroscopy reveals a long, spiral fracture of the distal femur. The fracture is reduced and fixed with an anatomic locking plate. The rest of the total hip arthroplasty proceeds uneventfully. Following surgery the surgeon has a meeting with the family and apologizes and provides full disclosure, accepts responsibility, provides a detailed explanation as to what happened, and gives reassurance that steps will be taken to prevent recurrences. This communication approach will most likely

Explanation

The surgeon has provided all the elements of good communication with the patient and family. His actions will lead to improved patient satisfaction, compared to nondisclosure and attempting to push or shirk responsibility.
In the event of a medical error or adverse event, effective communication with the patient and family is necessary. Effective communication should comprise: an apology, full disclosure (an explanation of what happened), accepting responsibility, and corrective steps that will be taken to prevent recurrence.While accepting responsibility is integral to the explanation process, it is different from accepting blame.
Mazor et al. found patients would more likely change physicians and seek legal advice in situations with a life-threatening outcome where physicians chose nondisclosure. They recommend full disclosure, acceptance of responsibility, an apology, detailed explanations, and assurances that steps will be taken to prevent recurrences will result in positive outcomes in terms of patient satisfaction, trust, and emotional response.
MacDonald et al. addressed medical errors in an editorial. Besides full disclosure, they feel that an apology is necessary. This includes an acknowledgement of the event and one’s role in the event, and a genuine expression of regret. Apology laws exist to to reduce concerns about legal implications of disclosure and apology.
Incorrect Answers:

Question 60

Acral metastases are most commonly seen in what type of carcinoma?

Explanation

DISCUSSION: Metastatic lesions to bone are usually located in the axial and proximal appendicular skeleton. Metastases below the elbow and knee are rare, but when they do occur they are most commonly from lung carcinoma.
REFERENCES: Hayden RJ, Sullivan LG, Jebson PJ: The hand in metastatic disease and acral manifestations of paraneoplastic syndromes. Hand Clin 2004;20:335-343.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 313.

Question 61

A 25-year-old lineman is referred to your office for a second opinion. 1 year ago, he underwent an arthroscopic procedure for shoulder instability. He complains of persistent sense of instability despite the surgery. Which of the following is a contraindication to revision arthroscopic labral repair for recurrent anterior glenohumeral instability? Review Topic

Explanation

Capsular attenuation or postthermal capsular necrosis from prior thermal capsulorraphy is a contraindicated to arthroscopic repair.
Thermal capsulorrhaphy utilizes heat generated by radiofrequency or laser ablation to cause capsular shrinkage in an effort to treat shoulder instability. However, high recurrence rates have been found, especially around two to three weeks after the index procedure, when the capsular tissue is the weakest. In the setting of recurrence following thermal capsulorrhaphy, open revision is recommended.
Creighton et al. reported on a series of 18 patients undergoing revision arthroscopic stabilization. Of the 18, 3 failed with recurrent instability, all with previous thermal capsulorrhaphy.
Miniaci et al. reviewed the outcomes following thermal capsulorrhaphy noting high rates of recurrent instability, especially in the setting of initial treatment for multidirectional instability.
Park et al. reported on a series of 14 patients undergoing revision following thermal capsulorrhaphy. Ten out of 14 patients had signs of capsular thinning, insufficiency and attenuation.
Wong et al. surveyed 379 shoulder surgeons on the complications following thermal capsulorrhaphy. Capsular insufficiency and thinning were commonly associated with recurrent instability.
Hecht et al. performed thermal capsulorrhaphy and biomechanical analysis of the capsule in a sheep model. The authors found that the capsule was weakest at the 2-3 week post-operative timepoint, leading to the highest rate insufficiency, attenuation and mechanical failure at this time.
Incorrect answers:

Question 62

A 34-year-old man presents to clinic with 4 months of right elbow pain. He began going to the gym and playing squash about 3 months ago. On exam, he is tender over the lateral aspect of the elbow and has pain with resisted wrist extension. Which of the following choices lists the correct compartment of the muscle typically involved in this disease and then lists its antagonist muscle? Review Topic

Explanation

The patient presents with lateral epicondylitis, which typically involves the origin of the extensor carpi radialis brevis (ECRB). ECRB is in the mobile wad compartment and its antagonist muscle is flexor carpi ulnaris.
Lateral epicondylitis is an overuse injury, typically secondary to repetitive pronation and supination motion in extension, that leads to inflammation of the ECRB origin at the elbow. Histological analysis typically shows vascular hyperplasia and disorganized collagen. Clinically, patients will have pain over the lateral elbow exacerbated by resisted wrist extension. ECRB, the most commonly involved muscle origin, is innervated by the deep branch of the radial nerve and inserts on the base of the 3rd metacarpal. As it is radial wrist extensor, its antagonist is the ulnar sided wrist flexor.
Brummel et al. reviewed the clinical presentation and management options for lateral epicondylitis. They report acute symptoms in younger patients and chronic symptoms in older patients. NSAIDs, extensor stretching and activity modification are the mainstay of nonsurgical treatment.
Bunata et al. studies 85 cadavar elbows to determine anatomic factors contributing to tennis elbow. They found that the ECRB undersurface rubs against the lateral capitellium in elbow extension leading to tendinosis.
Illustration A is cross-sectional diagram of the forearm with muscle bellies labeled. Notice the location of ECRB in the mobile wad. Illustration B is a coronal T2 MRI showing fluid signal and undersurface tearing near the extensor origin as can be seen in lateral epicondylitis.
Incorrect Answers:
1-4: The ECRB is in the mobile wad and its antagonist is flexor carpi ulnaris. All other answers are incorrect.

Question 63

When treating osteoporosis with alendronate, what is the most common side effect?

Explanation

DISCUSSION: Alendronate is a second-generation bisphosphonate, and it can cause epigastric distress in up to 30% of patients. This side effect can be minimized by gradually building up to therapeutic doses over a period of 4 to 8 weeks.
REFERENCES: Marshall JK, Rainsford KD, James C, et al: A randomized controlled trial to assess alendoronate-associated injury of the upper gastrointestinal tract. Aliment Pharmacol Ther 2000;14:1451-1457.
Lane JM, Sandhu HS: Osteoporosis of the spine, in Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 227-234.

Question 64

Figures 1 through 3 are the radiographs of a 27-year-old man who has had wrist pain since falling 1 day ago. Which treatment offers the best prognosis for prevention of carpal collapse and progressive arthritis?

Explanation

EXPLANATION:
Although this patient’s history includes a recent fall, the radiographs show evidence of a scaphoid nonunion with carpal collapse but no arthritis. Obtaining union of the scaphoid is important to prevent progressive carpal collapse and arthritic changes. ORIF with bone graft is most appropriate to obtain union and correct the collapse deformity. Screw fixation with volar wedge graft often is performed to realign a scaphoid humpback deformity, although cancellous bone graft also is a reasonable option. Vascularized bone graft is considered for a nonunion of long duration, avascular necrosis of the proximal pole, and failed prior surgery. Cast immobilization will not lead to union of the scaphoid. Percutaneous screw fixation is not indicated for the treatment of a displaced nonunion. A proximal
row carpectomy is a salvage procedure and is not indicated for this patient because there are no arthritic changes.

Question 65

Which of the following factors can contribute to patellar subluxation following routine total knee arthroplasty?

Explanation

DISCUSSION: Excessive resection of the lateral facet of the patella can lead to subluxation. Rotational alignment of the components can have a significant impact on patellar tracking. Internal rotation of the femoral component leads to more lateral alignment of the patella within the trochlear groove. Internal rotation and medial placement of the tibial component results in lateralization of the tibial tubercle with an increase in the Q angle. Excessive valgus alignment of the mechanical axis, or insufficient correction of preoperative valgus, has a similar effect on the Q angle, and both can result in a higher rate of tracking problems.
REFERENCE: Ayers DC, Dennis DA, Johanson NA, Pelligrini VD: Common complications of total knee arthroplasty. J Bone Joint Surg Am 1997;79:278-311.

Question 66

A healthy 25-year-old man sustains a grade IIIB open tibial fracture. Following appropriate debridement, irrigation, and stabilization with an external fixator, the soft-tissue injury is shown in Figure 30. What is the most appropriate definitive soft-tissue coverage procedure?

Explanation

DISCUSSION: This is a very large near circumferential defect with posterior as well as anterior skin and muscle injury. Bone is exposed. The posterior muscles cannot be rotated since they are part of the zone of injury. The bone and other poorly vascularized areas of this wound would not accept a skin graft. The best chance for limb salvage will be to obtain soft-tissue coverage with a free tissue transfer using the latissimus dorsi.
REFERENCES: Mathes SJ, Nahai F: Vascular anatomy of muscle: Classification and applications, in Mathes SJ, Nahai F (eds): Clinical Application for Muscle and Musculocutaneous Flaps. St Louis, MO, CV Mosby, 1982, p 20.
Bos GD, Buehler MJ: Lower-extremity local flaps. J Am Acad Orthop Surg 1994;2:342-351.

Question 67

An 8-year-old girl has had a painless enlarging mass of insidious onset in the left thigh for the past 3 weeks. Her mother denies any history of trauma, fever, or disease. Examination reveals a nontender, mobile mass in the left medial thigh. Her gait is normal. Figures 25a through 25d show the frog-lateral radiograph, the axial and coronal T1-weighted MRI scans, and the axial T2-weighted MRI scan. Biopsy results reveal a nonrhabdomyosarcoma soft-tissue sarcoma. The most appropriate treatment should consist of

Explanation

DISCUSSION: In childhood, the more common soft-tissue sarcomas are rhabdomyosarcoma, synovial sarcoma, and fibrosarcoma. Rhabdomyosarcoma, treated with radiation therapy and chemotherapy, is a round cell tumor and is inconsistent with this patient’s histologic findings. Synovial sarcoma can be monophasic or biphasic with both spindle and epithelial-like cells and is associated with the characteristic reciprocal chromosomal translocation of t(x:18)(p11;q11) which is not found in fibrosarcoma. Synovial sarcoma also can be associated with cystic loculated areas best seen in a T2-weighted MRI scan. Nonrhabdomyosarcoma childhood soft-tissue sarcomas are treated with surgical excision in conjunction with chemotherapy and/or radiation therapy. The histology reveals no inflammatory cells to suggest an abscess; therefore, antibiotics and drainage are unnecessary. The MRI scans clearly show a mass of soft tissue and no bone involvement; therefore, proximal femoral resection is not appropriate. Serial observation is not appropriate because of the history of enlargement and insidious onset.
REFERENCES: Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3. St Louis, MO, Mosby Year Book, 1995, p 757.
Gupta TD, Chaudhuri P (eds): Tumors of the Soft Tissues, ed 2. Stamford, CT, Appleton and Lange, 1998, p 605.

Question 68

-Figures 10a and 10b are the sagittal and coronal MRI scans of a 5-year-old boy who noticed “clicking” in his right knee. His family denied any trauma, but admitted that the child was active and fell frequently.Birth and developmental history were unremarkable, and specifically negative for other musculoskeletal conditions. On physical examination, there was no warmth, tenderness, or erythema, or effusion. The child had an audible and palpable clunk when the knee was taken from a position of extreme flexion to full extension. There was no anterior, posterior, medial, or lateral instability on examination or medial or lateral joint line tenderness. The child had not been systemically ill. Radiographs were unrevealing.What is the most likely diagnosis?

Explanation

Question 69

Following a vertebroplasty of L2, cement is noted to protrude directly anterior to the L2 vertebral body. The cement is closest to which of the following structures?

Explanation

DISCUSSION: At the level of L2, the liver and the vena cava lie to the right. The pancreas

and duodenum are anterior to the aorta. The aorta lies in the midline just in front of the

vertebral body.
REFERENCES: Clement CD: Anatomy: A Regional Atlas of Human Anatomy, ed 3.

Baltimore, MD, Munich, Germany, Urban and Schwarzberg, 1987, Figure 331.

Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, plate 328.

Question 70

What is the most appropriate treatment for a chordoma involving the sacrum?

Explanation

DISCUSSION: Chordomas are very radio- and chemotherapy resistant; therefore, en bloc resection with a negative margin is the preferred treatment. Lesions at or below S3 can be resected without compromising pelvis stability, and continence usually is maintained. The mean survival rate for patients with sacral chordomas is approximately 7 years. Patients with chordoma of the mobile (cervical, thoracic, or lumbar) spine have a mean survival rate of approximately 5 years. This difference is most likely the result of an earlier diagnosis.
REFERENCES: Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 123-133.
Stener B, Gunterberg B: High amputation of the sacrum for extirpation of tumors: Principles and technique. Spine 1978;3:351-366.
Stener B: Resection of the sacrum for tumors. Chir Organi Mov 1990;75:S108-S110.

Question 71

Figures 1 through 5 are the MR images of a 12-year-old boy with left lateral-sided knee pain following a football injury. He has a several-year history of recurrent knee pain that improves with rest. An examination reveals a moderate effusion. Range of motion is 0° to 90° and is limited by pain in deep flexion. He has tenderness to palpation along the lateral joint line, and no instability is noted. Treatment should include

Explanation

The MR images show a tear through a discoid lateral meniscus. A discoid meniscus is caused by a failure of apoptosis during development in utero and is considered a congenital abnormality. Discoid menisci are prone to tearing and can be caused by minimal trauma. There is no known genetic cause for this condition. Radiographic findings that may be present in the setting of a discoid meniscus include lateral joint space widening, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Contralateral discoid menisci are noted in 20% of patients. There are no other known associated conditions. Treatment of a symptomatic discoid meniscus should include partial meniscectomy and saucerization or repair.

Question 72

Based on the appearance of the imaging studies shown in Figures 11a through 11c, what structure has most likely been injured?

Explanation

DISCUSSION: The radiographs reveal marked lateral subluxation of the patella in a patient who has recurrent patellar instability. The medial patellofemoral ligament is the main restraint to lateral subluxation of the patella.
REFERENCES: Boden BP, Pearsall AW: Patellofemoral instability: Evaluation and management. J Am Acad Orthop Surg 1997;5:47-57.
Desio SM, Burks RT, Bachus KN: Soft tissue restraints to lateral patellar translation in the human knee. Am J Sports Med 1998;26:59-65.

Question 73

A 6 year-old-boy falls from his bunk bed and suffers the injury seen in Figures A and B. Upon presentation to the emergency room he is noted to have a pink hand with brisk capillary refill, but no palpable pulses. After closed reduction in the operating room and the procedure seen in Figures C and D, he remains well perfused, pulses are still not palpable, but triphasic pulses can be heard on doppler examination. What is the most appropriate course of action? Review Topic

Explanation

A "pink pulseless" hand, especially those with strong triphasic doppler signals can be treated with observation. In the presented case it would be appropriate to place long arm immobilization (cast or splint) and observe.
Pediatric supracondylar humerus fractures presenting with vascular compromise can present a challenge for clinical decision making. If the hand lacks adequate perfusion on presentation it requires emergent treatment with closed reduction and pinning. If perfusion does not return, then surgical exploration of the antecubital fossa is required. Treatment of the "pink pulseless hand" remains controversial. If the hand is well perfused but lacks palpable pulses then it should be expeditiously reduced and pinned. If the hand remains well perfused with triphasic doppler signals, no additional intervention is required. Recommendations vary if the hand is perfused, and pulses cannot be detected on palpation or doppler.
If there is a normal neurovascular exam on presentation, but abnormal after reduction and pinning, then one must consider that the reduction may have entrapped the brachial artery. If hardware removal and fracture re-displacement does not improve pulses/perfusion of the hand, or if the fracture can not be reduced without diminishing perfusion, then open reduction is indicated to evaluate the brachial artery.
Shah et al. present their preferred algorithm for treatment of a pink pulseless hand. They note that even with good clinical perfusion there may be a vascular injury or entrapment of the brachial artery. Thus they recommend if the hand is pink with no palpable pulse, perform a doppler exam. Triphasic doppler signals allow for observation, while abnormal or non-detectable doppler signals require surgical exploration. If an AIN or median nerve injury is present, exploration is considered. A diagram of their algorithm can be seen in Illustration A.
Weller et al. present a retrospective review of 1297 supracondylar humerus fractures. They had 20 patients (1.5%) with a pink pulseless hand with good doppler signals following closed reduction and fixation. These patients were treated with close observation. One patient developed inadequate perfusion nine hours after reduction and required vascular repair. The remaining 19 patients regained palpable pulses prior to discharge or prior to the first follow-up visit. They recommend observation despite non-palpable pulses as long as other signs of perfusion (capillary refill and doppler signals) suggest the hand is well perfused.
Figures A and B are AP and lateral radiographs of a type III supracondylar humerus fracture. Figures B and C demonstrate this fracture following closed reduction and percutaneous pinning with three lateral pins. Illustration A is a flow chart of a proposed decision making algorithm for a pink pulseless hand as presented by Shah et al.
Incorrect Answers:
reduction and fixation. Answer 2- Changing the pattern of fixation would only be indicated if the current construct did not provide stable fixation of the fracture. Answer 3- Following reduction and fixation of a supracondylar humerus fracture the most appropriate dressing is rigid long arm immobilization in a splint or cast. If there is concern for edema or perfusion then a cast should be bivalved. Answer 5- Surgical exploration of the antecubital fossa would be indicated if the hand had inadequate perfusion, or if the fracture could not be reduced and fixed without causing a notable decrease in pulses or perfusion.

Question 74

A 24-year-old man reports the development of a foot drop following a knee dislocation 1 year ago. The common peroneal nerve was found to be in continuity at the time of surgical reconstruction of the posterolateral corner of the knee joint. He would like to eliminate the need for an ankle-foot orthosis. What is the best option to achieve elimination of the orthosis?

Explanation

DISCUSSION: The ankle dorsiflexor muscles have been denervated for too long a period to expect reinnervation to be successful. Even if the extensor hallucis longus tendon was functional, it is unlikely to have sufficient strength to achieve dynamic ankle dorsiflexion. The tibialis posterior tendon transfer has been shown to predictably achieve these goals in a high percentage of patients. Successful ankle fusion is likely to fail with time due to the development of forefoot equinus.
REFERENCES: Pinzur MS, Kett N, Trilla M: Combined anteroposterior tibial tendon transfer in post-traumatic peroneal palsy. Foot Ankle 1988;8:27l-275.
Lipscomb P, Sanchez J: Anterior transplantation of the posterior tibial tendon for persistant palsy of the common peroneal nerve. J Bone Joint Surg Am 1961;43:60-66.

Question 75

A 30-year-old elite marathon runner reports chronic pain over the lateral aspect of the distal right leg and dysesthesia over the dorsum of the foot with active plantar flexion and inversion of the foot. Examination reveals a tender soft-tissue fullness approximately 10 cm proximal to the lateral malleolus. The pain is exacerbated by passive plantar flexion and inversion of the ankle. There is also a positive Tinel’s sign over the site of maximal tenderness. There is no motor weakness, and deep tendon reflexes are normal. Radiographs and MRI of the leg are normal. What is the next most appropriate step in management?

Explanation

DISCUSSION: The patient has entrapment of the superficial peroneal nerve against its fascial opening in the distal leg. It is typically exacerbated by passive or active plantar flexion and inversion of the foot, which leads to traction of the nerve as it exits this opening. Treatment involves release of the fascial opening to reduce this traction phenomenon. Closure of the defect will only aggravate the condition and potentially result in an exertional compartment syndrome. A four-compartment fasciotomy is only indicated for an established compartment syndrome of the leg.
REFERENCES: Styf J: Diagnosis of exercise-induced pain in the anterior aspect of the lower leg. Am J Sports Med 1988;16:165-169.
Sridhara CR, Izzo KL: Terminal sensory branches of the superficial peroneal nerve: An entrapment syndrome. Arch Phys Med Rehabil 1985;66:789-791.
Styf J: Entrapment of the superficial peroneal nerve: Diagnosis and results of decompression.
J Bone Joint Surg Br 1989;71:131-135.

Question 76

What is the most common complication associated with open reduction and internal fixation using a 90/90 plate configuration and olecranon osteotomy for an OTA type C2 distal humerus fracture?

Explanation

The most common complications associated with open reduction and internal fixation of distal humerus fractures are those associated with repair of an associated olecranon osteotomy. Complications associated with olecranon osteotomy fixation include failure of fixation (5%) and the need for secondary removal of painful hardware (70%). Nonunion of a distal humerus fracture treated with 90/90 plating is uncommon and results from inadequate fixation, excessive soft-tissue stripping, or use of inadequate plate fixation such as one third tubular plates. Heterotopic ossification is seen in approximately 4% of cases, infection 4%, and ulnar nerve palsy 7%. Although a relatively minor complication, the need for removal of painful hardware from the olecranon osteotomy is by far the most common complication seen in these cases.

Question 77

Figures 17a and 17b show the AP and lateral radiographs of a 75-year-old woman who reports giving way and shifting of the knee, particularly when she is descending stairs or ambulating on level surfaces. History reveals a total knee replacement 5 years ago. Treatment should consist of

Explanation

DISCUSSION: The radiographs show well-fixed components of a posterior cruciate-retaining total knee replacement. The relative position of the femoral component is anteriorly subluxated relative to the tibial component. The AP radiograph shows that the articular space is markedly asymmetric, indicating either failure or fracture of the polyethylene or subluxation of the femur relative to the tibia. The patient’s symptoms suggest a failure of the posterior cruciate ligament that is consistent with the radiographic findings; therefore, the treatment of choice is revision to a posterior cruciate-substituting implant.
REFERENCE: Pagnano MW, Cushner FD, Scott WN: Role of the posterior cruciate ligament in total knee arthroplasty. J Am Acad Orthop Surg 1998;6:176-187.

Question 78

A 37-year-old man with a history of congenital flatfoot reports worsening pain on the medial aspect of his ankle for the past year. The pain is worse with weight bearing and is better with rest and the use of an ankle brace. What findings are shown on the MRI scans shown in Figures 18a through 18c?

Explanation

DISCUSSION: The MRI scans reveal an enlarged posterior tibial tendon, with degenerative signal within the tendon and an excessive amount of fluid in its sheath. This is a type II tear, as noted by Conti and associates, which is the most commonly seen tear.
REFERENCES: Slovenkai MP: Clinical and radiographic evaluation (Adult flatfoot: Posterior tibial tendon dysfunction). Foot Ankle Clin 1997;2:241-260.
Conti S, Michelson J, Jahss M: Clinical significance of magnetic resonance imaging in preoperative planning for reconstruction of posterior tibial tendon ruptures. Foot Ankle 1992;13:208-214.

Question 79

A 57-year-old man has had right ankle pain for the past 10 months following an injury that went untreated. Radiographs are shown in Figures 30a through 30c. Management should consist of

Explanation

DISCUSSION: The radiographs reveal a malunited distal fibular fracture with shortening. Because there appears to be an adequate cartilage space within the ankle joint, the role of reconstruction would be to prevent arthrosis and the need for ankle arthrodesis, as well as to decrease symptoms. The treatment of choice is restoration of fibular length, alignment, and rotation with osteotomy plating, and bone grafting as needed. There is no indication for ligament reconstruction of a mechanically stable ankle, and tibial shortening osteotomy will not assist in correcting the deformity. Cast immobilization may assist with improvement of symptoms but will not correct the overall process. Determination of fibular length is best done by comparing the talocrural angle of the injured side with the uninjured side. The goal is to perfectly reduce the talus in the ankle mortise.
REFERENCES: Marti RK, Raaymakers EL, Nolte PA: Malunited ankle fractures: The late results of reconstruction. J Bone Joint Surg Br 1990;72:709-713.
Geissler W, Tsao A, Hughes J: Fractures and injuries of the ankle, in Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD (eds): Rockwood and Green’s Fractures in Adults, ed 4. Philadelphia, PA, Lippincott-Raven, 1996, pp 2201-2206.
Yablon IG, Leach RE: Reconstruction of malunited fractures of the lateral malleolus. J Bone Joint Surg Am 1989;71:521-527.

Question 80

A 26-year-old man has had a 2-year history of pain and stiffness after sustaining a comminuted olecranon fracture. Treatment at the time of injury consisted of open reduction and internal fixation with tension band wiring. Examination reveals motion of 45 degrees to 110 degrees and pain throughout the arc of motion. Resisted flexion and extension are painful. Forearm rotation is normal. Radiographs are shown in Figure 51. Treatment should consist of

Explanation

DISCUSSION: The patient has posttraumatic arthritis of the elbow; therefore, the treatment of choice is hardware removal and soft-tissue releases with splinting to avoid recurrence of contractures. The combination of pain and stiffness in an elbow that has sustained significant joint surface damage renders it unresponsive to simple soft-tissue releases and heterotopic bone excision. Joint distraction and interposition arthroplasty offer the possibility of maintaining motion and relieving pain as a later salvage procedure. Joint replacement should not be performed in young, active, strong individuals because the prosthesis will fail quickly and complications will develop. Synovectomy and radial head excision are not indicated.
REFERENCES: Morrey BF: Distraction arthroplasty: Clinical applications. Clin Orthop 1993;293:46-54.
O’Driscoll SW: Elbow arthritis: Treatment options. J Am Acad Orthop Surg 1993;1:106-116.

Question 81

Figures 38a & 38b show radiographs of a 40 year old man who underwent a Putti-Platt repair for recurrent dislocations at age 22. He reports increasing pain in the shoulder and limited motion for five years. Examination reveals 130 degrees of elevation and 15 degrees of external rotation. Non-surgical treatment has failed. Treatment should now consist of what?

Explanation

[Radiograph: Well positioned G-H joint. Mild degenerative changes.]
Late onset of pain (average 13 years) was noted following this procedure in a small number of patients. The pain is attributed to excessive G-H compressive forces due to limited external rotation. NSAIDS and PT are first line treatments. If these fail, the authors demonstrated good results with release of the anterior structures. Choices 3 & 4 would probably be reserved for patients older than 50 with more advanced signs of degenerative disease.

Question 82

A 15-year-old right-handed pitcher reports shoulder pain after throwing. His symptoms have been present for 3 months and have been getting progressively worse. Clinical examination shows no atrophy of the shoulder muscles, but he has pain with resisted motion of the shoulder, especially internal rotation. Radiographs are shown in Figures 73a and 73b. What is the next step in the evaluation and treatment of his shoulder pain? Review Topic

Explanation

The patient has proximal humeral epiphyseolysis, otherwise known as "Little League shoulder." This is an overuse injury of the shoulder in the skeletally immature overhead throwing athlete. Most frequently seen in pitchers, it usually develops after an increase in the amount or intensity of throwing activity. Initial treatment involves cessation of throwing activities so the proximal humeral growth plate injury can heal, followed by a gradual return to throwing.

Question 83

The function of which of the following structures is to resist internal tibial rotation with the knee in full extension? Review Topic

Explanation

The primary function of the posterior oblique ligament is to resist internal tibial rotation with the knee in full extension.
The posterior oblique ligament is a structure within the posteromedial corner of the knee, with attachments proximally to the adductor tubercle of the femur and distally to the tibia/posterior knee capsule. The posterior oblique ligament and posteromedial capsule play a significant role in the prevention of additional posterior tibial translation in the knee in the setting of posterior cruciate ligament injury. They also act to resist internal tibial rotation with the knee in full extension.
Griffith et al. reports that the posterior oblique ligament provides significant resistance to valgus and internal rotation forces with knee extension. They used a cadaver model and demonstrated that the superficial MCL resists valgus and external rotation forces more than the posterior oblique ligament, while the posterior oblique ligament is more involved in resisting internal rotation.
Tibor et al. reviews the anatomy of the posteromedial corner of the knee. They report that failing to recognize injury to these structures may cause failure of cruciate ligament reconstruction surgery, and that reconstruction or repair of the posteromedial corner may be indicated in the face of multiple ligament injuries.
Illustration A shows the posteromedial corner of the knee, including the posterior oblique ligament.
Incorrect answers:
1-4: These structures are not primary restraints to internal tibial rotation in full extension.

Question 84

An 80-year-old African American woman who lives in a large city is scheduled for total hip arthroplasty to address primary osteoarthritis. Part of the presurgical protocol includes nasal swab screening to assess for methicillin-resistant Staphylococcus aureus (MRSA) colonization. Which demographic factor places this patient at highest risk for a positive result?

Explanation

DISCUSSION:
Demographic factors are associated with increased risk for MRSA colonization, so it is important to identify vulnerable patients. Female gender and advanced age reduce the risk for colonization, whereas African American race increases this risk. Urban environments do not influence MRSA colonization.

Question 85

A 66-year-old male undergoes the procedure shown in figures A and B. After 4 years, he develops progressive pain and limitations in his daily function that is refractory to conservative measures. He is indicated for conversion to a total knee replacement with almost complete relief of his symptoms postoperatively. What preoperative factor likely led to the subsequent failure?

Explanation

unicompartmental arthroplasty. The absence of an ACL is a contraindication for mobile-bearing UKA.

OrthoCash 2020
Which of the following is the most common cause of early revision surgery (<20 weeks) following a hip resurfacing arthroplasty?
Periprosthetic fracture
Rupture of abductors
Dislocation
Heterotopic ossification
Post-operative stiffness
Periprosthetic fracture, specifically femoral neck fracture, is the most common cause of early revision less than 20 weeks following surgery.
The rate of femoral neck fractures following hip resurfacing varies, but most literature reports a rate of 1%. A majority of these fractures happen in the early post-operative period and are the most frequent cause of revision surgery within several months following surgery. The cause is usually multifactorial, but placing the femoral implant in varus, osteonecrosis, and notching have been proven risk factors for fracture.
Little el al. report on 377 patients undergoing hip resurfacing. 13 required revision including 8 for fracture of the femoral neck and 3 for loosening of a component. Evidence of osteonecrosis was seen in two of these cases, leading the authors to believe it may contributed to fracture.
Illustration A shows a comparison of a typical total hip replacement and a hip resurfacing arthroplasty. Illustration B shows notching of the femoral neck, a known cause of femoral neck fracture following hip resurfacing. Illustration C shows a femoral neck fracture in a patient with a hip resurfacing.

OrthoCash 2020
A 55-year-old male undergoes a revision total knee arthroplasty of an implant that is only 3 years old. At the time of surgery, the tibial polyethylene liner shows catastrophic delamination and cracking. What is the most likely cause of this extensive, accelerated wear of the polyethylene liner?
Sterilization in ethylene oxide
Gamma irradiation of the polyethylene liner in the presence of air
Gamma irradiation of the polyethylene liner with vacuum packaging
Gamma irradiation of the polyethylene liner in nitrogen
Gamma irradiation of the polyethylene liner in argon Corrent answer: 2
Irradiation of polyethylene in air (i.e. oxygen present) has been shown to be a risk factor for catastrophic failure after total knee replacement.
Free radicals are generated when polyethylene is irradiated in the presence of air. Initially, these free radicals result in cross-linking. However, if the polyethylene is exposed to these free radicals for an extended period of time, delamination, cracking, and catastrophic failure may ensue. The industry has completely abandoned this method of sterilization as a result. Currently, the standard of care is irradiation of polyethylene in an inert gas (e.g. argon, nitrogen or vacuum packaging). The amount of oxidative products when polyethylene is sterilized in the absence of oxygen is much less and does not lead to catastrophic failure.
Sterilization without irradiation is another option (ethylene oxide). When this occurs, there is no cross-linking and thus the increased wear properties are lost. However, since there is no oxidization, you do not have the risk of catastrophic failure as seen in those liners irradiated in the presence of oxygen.
The cited reference by McNulty et al. from Orthopedics discusses the influence of sterilization methods on wear performance. They found that gamma irradiation and storage of the polyethylene components in an essentially oxygen-free environment imparted by gamma irradiation in a vacuum foil pouch (GVF) protects the components from oxidization.
Illustration A shows a polyethylene liner that has undergone catastrophic wear as a result of irradiation in the presence of oxygen.
Incorrect Answers:
catastrophic wear, although wear properties are less than gamma irradiation in the absence of air.

OrthoCash 2020
Which of the following interventions reduces osteolysis around distal portion of the femoral stem when performing a total hip arthroplasty?
Use of an extended offset femoral neck component
Use of a proximal circumferentially coated ingrowth stem
Use of a collared stem
Use of a long femoral stem
Ensuring that the stem fills the diaphysis of the femur Corrent answer: 2
Osteolysis of the femur is caused by activation of macrophages by microscopic polyethylene particles within the "effective joint space", defined as any area where joint fluid can come into contact with bone. This can occur above the acetabular cup, through screw holes, and down the femoral shaft around the prosthetic stem. Ideally, with a cementless stem, both the proximal and metaphyseal femur are well filled by the prosthesis. Collared stems are used to augment poor calcar bone quality or bone loss.
Sinha et al showed in a retrospective review of 101 hips with cementless circumferentially coated femoral stems no distal femur osteolysis occurred, but 82% showed “evidence of proximal femur stress shielding”, though only 38% showed proximal femoral osteolysis.
OrthoCash 2020
During a minimally invasive approach to total hip arthroplasty a femoral periprosthetic fracture occurs. Which of the following steps is crucial to properly treat this complication?
Transitioning to an extensile approach to adequately visualize and reduce the fracture
Limiting post-operative weight bearing
Switching to a cemented femoral stem to avoid the stresses created during press-fit fixation
Delaying the arthroplasty until the fracture has healed
Supplementing the fracture with autograft Corrent answer: 1
Proper treatment of an intraoperative femoral fracture during total hip arthroplasty involves adequate exposure, anatomic reduction, and bypassing the fracture site by 2 cortical diameters of the femur with a long stem. This may involve repositioning the patient on the table if the arthroplasty is performed in the supine position. Minimally invasive surgical techniques have been developed to insert the components through smaller exposures and less soft tissue dissection. The purported advantages include faster rehabilitation, less blood loss, shorter hospital stays, and better cosmesis. However, complications an arise if the surgeon sacrifices surgical exposure and visualization.
Fehring et al review 3 cases of total hip arthroplasty performed through minimally invasive techniques with catastrophic outcomes. Intra-operative fracture, chronic instability, and death were all identified.
OrthoCash 2020
A 70-year-old man underwent total hip arthroplasty 4 months ago and has experienced 3 dislocations. Radiographs reveal no failure of the hardware and an acetabular component that has an abduction
angle of 40 degrees and a version of 10 degrees retroverted. What is the most appropriate treatment for the recurrent dislocations?
hip abduction brace
revision of the acetabular liner to a constrained type
revision of the entire acetabular component
revision of the femoral head to a larger size
revision to an extended offset prosthesis Corrent answer: 3
Per Dorr et al: post-operative hip instability can be caused by several factors: soft tissue imbalance, component malposition, or position. Component malposition, as in this case, should be treated with revision of the offending component. In this case the acetabulum was placed in retroversion when it should have been 15-20 degrees anteverted. None of the other options addresses the cause of the instability. According to Morrey, the most signficant risk factors to instability are prior hip surgery, trochanteric nonunion, and posterior surgical approach. He wrote that the most reliable way to correct instability is to reorient a retroverted acetabular cup.
OrthoCash 2020
In patients with sickle cell disease and asymptomatic osteonecrosis of the femoral head identified with magnetic resonance imaging, what percentage will eventually go on to femoral head collapse?

Question 86

A 15-year-old dancer who has had brief episodes of back pain over the past 2 years now reports a 3 month history of low back pain and a decreased tolerance for dance. Figure 22a-c show flexion and extension x-rays and CT scan. She reports no leg pain, nor any bowel or bladder difficulties. Management should now consist of

Explanation

rays show a Grade I spondylolisthesis. Studies have shown that pts with grade 3 or 4 spondylolisthesis had a minimal success (8%) with nonoperative treatment, whereas pts with grade 1 or 2 spondylolisthesis had significant relief of pain. Conservative tx included rest, NSAIDs, abdominal strengthening exercises, hamstring stretching exercises, or traction.

Question 87

A 35-year-old man presents one week after an acute right shoulder posterior dislocation after being electrocuted. He is evaluated in the emergency department and undergoes closed reduction. The patient reports global right shoulder pain and limited active and passive range of motion. He has mild anterior and lateral bruising. He is distally neurovascularly intact. Current radiographs and an MRI scan are shown in Figures 1 through 3. What is the best next step?

Explanation

A 68-year-old man presents with chronic progressive right shoulder pain and loss of motion. He has active shoulder elevation of 120° and 5-/5 shoulder forward flexion strength limited by pain. He has exhausted nonsurgical management over the past year and is now interested in surgical intervention. Figure 1 is the preoperative axial CT scan of his shoulder. During surgical reconstruction, the surgeon should anticipate the location of maximal glenoid erosion to be

Question 88

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

Explanation

DISCUSSION: 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.
REFERENCE: Tortolani JP, McAfee PC, Saiedy S: Failures of lumbar disc replacement. Sem Spine Surg 2006;18:78-86.

Question 89

Storage of musculoskeletal allografts by cryopreservation is achieved by

Explanation

DISCUSSION: Cryopreservation uses chemicals to remove cellular water and controlled rate freezing to prevent ice crystal formation. The tissue is procured, cooled to wet ice temperature for quarantine, and then stored in a container with cryoprotectant solution of dimethyl
sulfoxide or glycerol which displaces the cellular water. The controlled rate freezing is then done to prevent ice crystal formation. Fresh allografts are not frozen in order to maintain maximum cellular viability, and this process limits the shelf life of osteochondral allografts. Freeze-drying involves replacement of water in the tissue with alcohol to a moisture level of
5% and then uses a vacuum process to remove the alcohol from the tissue. Preparation of fresh frozen grafts involves freezing the graft twice and packaging the tissue without solution at
minus 80 degrees C.
REFERENCES: American Association of Tissue Banks: Standards for Tissue Banking. MacLean, VA, American Association of Tissue Banks, 1999.
Vangsness CT Jr, Triffon MJ, Joyce MJ, et al: Soft tissue allograft reconstruction of the human knee: A survey of the American Association of Tissue Banks. Am J Sports Med 1996;24:230-234.
Brautigan BE, Johnson DL, Caborn DM, et al: Allograft tissues, in DeLee JC, Drez D Jr (eds): Orthopaedic Sports Medicine: Principles and Practice. Philadelphia, PA, WB Saunders, 2003, pp 205-213.

Question 90

Which clinical signs are consistent with the diagnosis of cauda equina syndrome?

Explanation

DISCUSSION
Cauda equina syndrome is a lower-motor neuron deficit. Hyperreflexia, clonus, and other upper-motor neuron findings would not be seen. Saddle anesthesia, motor weakness, and neurogenic bladder are elements critical to the diagnosis of cauda equina syndrome.
RECOMMENDED READINGS
Kostuik JP, Harrington I, Alexander D, Rand W, Evans D. Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am. 1986 Mar;68(3):386-91. PubMed PMID: 2936744. View Abstract at PubMed
Spector LR, Madigan L, Rhyne A, Darden B 2nd, Kim D. Cauda equina syndrome. J Am Acad Orthop Surg. 2008 Aug;16(8):471-9. Review. PubMed PMID: 18664636. View Abstract at PubMed
CLINICAL SITUATION FOR QUESTIONS 78 THROUGH 80
Figures 78a and 78b are the axial and sagittal MR images of an otherwise healthy 24-year-old woman who has had 8 weeks of severe leg pain without weakness.

A B

Question 91

The peroneus tertius is a commonly used landmark for arthroscopic portal placement. What is the function of this tendon?

Explanation

DISCUSSION: The peroneus tertius, although absent in 10% of the population, originates on the distal third of the extensor surface of the fibula and inserts onto the base of the fifth metatarsal, possibly extending to the fascia over the fourth interosseous space. The muscle is located in the anterior compartment of the leg and is innervated by the deep peroneal nerve. The tendon produces dorsiflexion and eversion when walking and can be used as an insertion point during tendon transfers to assist dorsiflexion. This tendon is peculiar to humans and is a proximally migrated deep extensor of the fifth toe.
REFERENCES: Joshi SD, Joshi SS, Athavale SA: Morphology of the peroneus tertius muscle.

Clin Anat 2006;19:611-614.
Williams PL, Bannister LH, Berry MM, et al (eds): Gray’s Anatomy, ed 38. London, Churchill Livingston, 1995, p 883.
Hansen ST Jr: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott Williams & Wilkins, 2000, p 21.

Question 92

..The optimal method to treat a recurrent presentation of pigmented villonodular synovitis (PVNS) with diffuse joint involvement in a 24-year-old woman with pain and symptomatic effusions is

Explanation

Question 93

Histologically, synovial chondromatosis is characterized by

Explanation

DISCUSSION: Histologically, there is metaplastic cartilage arising from the synovium. These lobules of zonates hyaline cartilage are of variable size, are embedded within edematous synovium, and protrude into the joint. The lobules calcify and ossify, leading to the characteristic radiographic appearance. Inflammatory synovitis is not characteristic of synovial chondromatosis. The fluid is clear and serosanguin, not blood tinged.
REFERENCES: Milgram JM: Synovial osteochondromatosis: A histopathological study of thirty cases. J Bone Joint Surg Am 1977;l59:792-801.
Murphy FP, Dahlin DC, Sullivan CR: Articular synovial chondromatosis. J Bone Joint Surg Am 1962;44:77.

Question 94

A 14-year-old girl has had mild pain and nail deformity of the great toe for the past 4 months. A radiograph is shown in Figure 50. What is the most likely etiology of the lesion?

Explanation

DISCUSSION: The lesion is typical of a subungual exostosis, which is most often found on the medial aspect of the great toe in children and young adults. The diagnosis is confirmed on radiographs and usually requires excision for relief.
REFERENCES: Lokiec F, Ezra E, Krasin E, Keret D, Wientraub S: A simple and efficient surgical technique for subungual exostosis. J Pediatr Orthop 2001;21:76-79.
Letts M, Davidson D, Nizalik E: Subungual exostosis: Diagnosis and treatment in children. J Trauma 1998;44:346-349.
Davis DA, Cohen PR: Subungual exostosis: Case report and review of the literature. Pediatr Dermatol 1996;13:212-218.

Question 95

A 23-year-old baseball pitcher who has diffuse pain along the posterior deltoid reports pain during late acceleration and follow-through. Examination of his arc of motion from external rotation to internal rotation at 90 degrees of shoulder abduction reveals a significant deficit in internal rotation when compared to the nonthrowing shoulder. Initial management should consist of

Explanation

DISCUSSION: Loss of internal rotation is common among overhead throwers and tennis players. Posterior capsular stretching can improve symptoms when accompanied by rest and gradual resumption of throwing. To avoid a false impression of improvement, cortisone injection is not recommended. Pitching through pain can cause further damage to the labrum and capsule. A sling and external rotator strengthening will not improve internal rotation.
REFERENCES: Kibler WB: Biomechanical analysis of the shoulder during tennis activities. Clin Sports Med 1995;14:79-85.
Jobe FW, Tibone JE, Jobe CM, Kvitne RS: The shoulder in sports, in Rockwood CA, Matsen FA (eds): The Shoulder. Philadelphia, PA, WB Saunders, 1990, pp 961-990.

Question 96

The mechanism for the osseous destruction is attributable to

Explanation

DISCUSSION
This scenario is a classic example of the development of Charcot foot. A red, swollen, deformed foot without ulceration suggests neuroarthropathy. Normal inflammatory marker findings, no history of fever or chills, and radiographs demonstrating bone loss support the diagnosis. Limb elevation with dramatic reduction in erythema is also characteristic of this disease process and does not occur with infection. Total-contact casting is the cornerstone of treatment for acute Charcot disease. Hemoglobin A1C is an indicator of glucose averaged over a 3-month period, providing the most reliable indication of a patient's ongoing glucose control. The pathophysiology of bone destruction is believed to be hypervascularity of bone. Infection and Charcot disease may develop simultaneously, but the combination is rare.
RECOMMENDED READINGS
Kaynak G, Birsel O, Güven MF, Ogüt T. An overview of the Charcot foot pathophysiology. Diabet Foot Ankle. 2013 Aug 2;4. doi: 10.3402/dfa.v4i0.21117.Print 2013. PubMed PMID: 23919113.View Abstract at PubMed
Pinzur MS, Lio T, Posner M. Treatment of Eichenholtz stage I Charcot foot arthropathy with a weightbearing total contact cast. Foot Ankle Int. 2006 May;27(5):324-9. PubMed PMID: 16701052. View Abstract at PubMed

Question 97

Which of the following is an advantage of using blocking screws for tibial nailing?

Explanation

DISCUSSION: Blocking screws can be used to help obtain and maintain reductions, increase construct stiffness, and neutralize translational forces. There are no studies as of yet that find a blocking screw to decrease nail failure.
Krettek found that medial and lateral blocking screws can increase the primary stability of distal and proximal metaphyseal fractures after nailing and can be an effective tool for selected cases that exhibit malalignment and/or instability by decreasing mechanically measured deformation.
In a later clinical study, Krettek found that after using blocking screws, tibial healing was evident radiologically at a mean of 5.4 months with a decreased rate of malunions.
Ricci also found that blocking screws are effective to help obtain and maintain alignment of fractures of the proximal third of the tibial shaft treated with intramedullary nails.

Question 98

A 56-year-old man underwent right total shoulder arthroplasty 2 months ago. Recently while reaching with his shoulder in a flexed and adducted position, he noted shoulder pain and afterwards he could not externally rotate his arm. An axillary radiograph is shown in Figure 30. What is the most likely cause of this problem?

Explanation

DISCUSSION: Anteversion of the humeral component may result in anterior instability of the component. Posterior instability after total shoulder arthroplasty is usually the result of some combination of the following factors: untreated anterior soft-tissue contractures, excessive posterior capsular laxity, and excessive retroversion of the humeral and/or glenoid components.
REFERENCES: Cofield RH, Edgerton BC: Total shoulder arthroplasty: Complications and revision surgery. Instr Course Lect 1990;39:449-462.
Wirth MA, Rockwood CA Jr: Complications of total shoulder replacement arthroplasty. J Bone Joint Surg Am 1996;78:603-616.

Question 99

Which of the following ligaments is the primary static restraint against inferior translation of the arm when the shoulder is in 0 degrees of abduction?

Explanation

DISCUSSION: The superior glenohumeral ligament (SGHL) and coracohumeral ligament serve as primary static restraints against inferior translation of the arm when the shoulder is in 0 degrees of abduction. Of these, the coracohumeral ligament has been shown to have a greater cross-sectional area, greater stiffness, and greater ultimate load than the SGHL. The inferior glenohumeral ligament plays a greater stabilizing role with increasing abduction of the arm. The coracoacromial ligament may help provide superior stability, especially when the rotator cuff is deficient. The coracoclavicular ligaments stabilize the acromioclavicular joint.
REFERENCES: Boardman ND, Debski RE, Warner JJ, et al: Tensile properties of the superior glenohumeral and coracohumeral ligaments. J Shoulder Elbow Surg 1996;5:249-254.
Warner JJ, Deng XH, Warren RF, Torzilli PA: Static capsuloligamentous restraints to superior-inferior translation of the glenohumeral joint. Am J Sports Med 1992;20:675-685.

Question 100

A 13-year-old boy has a mild deformity of the left sternoclavicular joint after being involved in a rollover accident while riding an all-terrain vehicle. Examination in the emergency department reveals that he is hemodynamically stable, and his neurovascular examination is normal. The CT scan shown in Figure 22 was obtained because radiographs were inconclusive. Management should consist of

Explanation

DISCUSSION: The CT scan reveals a completely displaced physeal fracture of the medial clavicle with marked posterior displacement of the distal fragment. This fracture pattern is associated with potential injury to the vascular structures of the mediastinum. Reduction should be performed for this fracture and generally can be done closed with shoulder retraction and upward pull on the clavicle with a towel clip. Once reduced, the fracture is relatively stable and typically will heal in good position. Reduction should be performed in the operating room in the event that a vascular injury is detected once compression is removed from the clavicle. Open reduction may be necessary if closed reduction is not possible; however, pinning or ligament reconstruction usually is not necessary.
REFERENCES: Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA,

WB Saunders, 1998, p 581.
Wirth MA, Rockwood CA Jr: Acute and chronic traumatic injuries of the sternoclavicular joint. J Am Acad Orthop Surg 1996;4:268-278.

Full Question & Answer Text (for Search Engines)

Question 1:

What is the most common long-term complication of the fracture shown in Figure 32?

Options:

Nonunion
Ankle arthritis
Subtalar arthritis
Talonavicular arthritis
Posterior tibial tendinitis

Correct Answer: Subtalar arthritis

Explanation:

Question 2:

In a postganglionic brachial plexus lesion at Erb’s point (point of formation of the upper trunk by the C5 and C6 nerve roots), which of the following nerves will still function normally?

Options:

Suprascapular
Musculocutaneous
Axillary
Lateral pectoral
Dorsal scapular

Correct Answer: Dorsal scapular

Explanation:

Question 3:

The plate seen in Figure 48a was applied to the fracture seen in Figure 48b, and is functioning in what capacity?

Options:

Buttress
Neutralization
Tension band
Compression
Distraction

Correct Answer: Neutralization

Explanation:

Question 4:

- A 17-year old boy who sustained a closed clavicle fracture after he was ejected from an all-terrain vehicle was treated with a figure-of-8 brace 1 year ago. He now reports continuous pain at the site of the fracture and is unable to actively raise his arm above his head. A radiograph is shown in Figure 1. Management should now include

Options:

an onlay bone graft
electrical stimulation
resection of the distal clavicle
plate fixation and a bone graft
smooth Kirschner wire fixation and a bone graft

Correct Answer: smooth Kirschner wire fixation and a bone graft

Explanation:

Question 5:

Options:

closed right femoral shortening.
left femoral lengthening.
left tibial lengthening.
a left 3-cm shoe lift.
epiphyseodesis of the right distal femur and proximal tibia.

Correct Answer: left femoral lengthening.

Explanation:

DISCUSSION: The patient has a projected limb-length discrepancy of 7 cm. This includes the 4 cm she already has, plus 3 cm expected growth of the uninvolved distal femur during the 3 years of growth she has remaining. She also has moderate limb deformity. Femoral lengthening is considered the treatment of choice because it can address both the limb-length discrepancy and the deformity. Epiphyseodesis will not result in limb-length equality at maturity, with only approximately 1.8 cm of equalization expected from this procedure. Use of closed femoral shortening of 7 cm runs the risk of weakening the quadriceps on the normal side and will leave the patient with a remaining residual valgus deformity. Tibial lengthening will leave the knees at different levels. A shoe lift can be prescribed as a temporary measure but is not a good
long-term solution.
REFERENCES: Westh RN, Menelaus MB: A simple calculation for the timing of epiphyseal arrest: A further report. J Bone Joint Surg Br 1981;63:117-119.
Sasso RC, Urquhart BA, Cain TE: Closed femoral shortening. J Pediatr Orthop 1993;13:51-56.
Nordsletten L, Holm I, Steen H, Bjerkreim I: Muscle function after femoral shortening osteotomies at the subtrochanteric and mid-diaphyseal level: A follow-up study. Arch Orthop Trauma Surg 1994;114:37-39.

Question 6:

Options:

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

Correct Answer: Proximal tibial osteotomy with subsequent ACL reconstruction

Explanation:

Question 7:

- What is the treatment of choice for an adult who has an isolated fracture of the ulna at the junction of the distal and middle thirds, with 5 degrees apex dorsal angulation and 25% displacement?

Options:

Intramedullary rodding
Functional bracing
Closed reduction and a long arm cast
Closed reduction and application of an external fixator
Open reduction and internal fixation with a dorsal plate

Correct Answer: Functional bracing

Explanation:

Question 8:

What is the most common complication after distal biceps tendon repair at the elbow?

Options:

Lateral antebrachial cutaneous neuritis
Radial sensory neuritis
Symptomatic heterotopic ossification
Rupture of the repair

Correct Answer: Lateral antebrachial cutaneous neuritis

Explanation:

Question 9:

Which of the following growth factors binds and activates the lipoprotein receptor-related protein 5/6 (LRP5/6) during bone development? Review Topic

Options:

Transforming growth factor-beta
Platelet-derived growth factor
Parathyroid hormone
Bone morphogenetic protein
Wnt protein

Correct Answer: Wnt protein

Explanation:

Question 10:

A 60-year-old woman with a history of breast cancer has progressive paraparesis. The MRI scan is shown in Figure 28. What form of management is most likely to restore or maintain ambulation?

Options:

Radiation therapy and a thoracolumbosacral orthosis
Laminectomy alone
Laminectomy and radiation therapy
Laminectomy and posterior fusion
Anterior decompression and stabilization

Correct Answer: Anterior decompression and stabilization

Explanation:

Question 11:

Options:

Lateral radiographs with passive flexion/extension views
Helical CT scan of the cervical-thoracic region
Careful manual palpation of the cervical spine for subtle defects or step-offs
MRI of the cervical spine
Continued use of the cervical collar until the patient becomes responsive for examination

Correct Answer: Helical CT scan of the cervical-thoracic region

Explanation:

Question 12:

Options:

observation.
steroid injection.
curettage and bone grafting.
wide resection with neoadjuvant chemotherapy.
debridement, irrigation, and intravenous antibiotics.

Correct Answer: curettage and bone grafting.

Explanation:

Question 13:

Options:

Dega iliac
Salter iliac
Pemberton iliac
Steele triple
Ganz or Bernese periacetabular

Correct Answer: Dega iliac

Question 14:

According to Musculoskeletal Infection Society (MSIS) guidelines, which set of patient laboratory study results fits the definition of chronic prosthetic joint infection?

Options:

Erythrocyte sedimentation rate (ESR) 50 mm/hr, C-reactive protein (CRP) 8 mg/L, joint aspiration white blood cell (WBC) count 542, 62% neutrophils, and positive leukocyte esterase
ESR 42 mm/hr, CRP 12 mg/L, joint aspiration WBC count 3,540, 72% neutrophils, and positive leukocyte esterase
ESR 20 mm/hr, CRP 15 mg/L, joint aspiration WBC count 4,135, 54% neutrophils, and negative leukocyte esterase
ESR 25 mm/hr, CRP 7 mg/L, joint aspiration WBC count 252, 82% neutrophils, and negative leukocyte esterase

Correct Answer: ESR 42 mm/hr, CRP 12 mg/L, joint aspiration WBC count 3,540, 72% neutrophils, and positive leukocyte esterase

Explanation:

Question 15:

Options:

Axillary view
CT of the shoulder
Closed reduction
Sling and close follow-up
Functional brace

Correct Answer: Axillary view

Explanation:

DISCUSSION: The next step in the management of this injury is completion of the shoulder trauma series. An axillary radiograph, which can be quickly performed in the emergency department, must be obtained to accurately assess the humeral head relationship to the glenoid. If difficulty is encountered, a “Velpeau” axillary may be substituted. If that fails to elucidate the status of the glenohumeral joint, a CT scan should be obtained.
REFERENCE: Simon JA, Puopolo SM, Capla EL, et al: Accuracy of the axillary projection to determine fracture angulation of the proximal humerus. Orthopedics 2004;27:205-207.

Question 16:

Options:

0% increase
25% increase
50% increase
25% decrease
50% decrease

Correct Answer: 0% increase

Explanation:

Question 17:

Options:

Add double metal uprights and a leather corset.
Add a supracondylar suspension to the soft suspension.
Add supracondylar and suprapatellar suspensions to the socket design.
Replace the socket insert with a silicone suction socket with locking bolt suspension.
Replace the prosthetic socket with a negative pressure vacuum system.

Correct Answer: Add double metal uprights and a leather corset.

Explanation:

Question 18:

Options:

Continued semi-rigid immobilization until the extremity surgeries are completed
Halo skeletal fixation prior to the extremity surgery
Definitive clearance of the cervical spine with CT and/or MRI
Removal of the semi-rigid collar and physical examination when the patient is responsive
Soft collar immobilization and local wound care

Correct Answer: Definitive clearance of the cervical spine with CT and/or MRI

Explanation:

DISCUSSION: Ackland and associates demonstrated that the failure to achieve early spinal clearance in an unconscious blunt trauma patient predisposed the patient to increased morbidity secondary to the prolonged used of cervical immobilization. They demonstrated that the four significant predictors of collar-related ulcers were ICU admission, mechanical ventilation, the necessity for cervical MRI, and the time to cervical spine clearance and collar removal. The risk of pressure-related ulceration increased by 66% for every 1-day increase in Philadelphia collar time and this highlights the need for definitive C-spine clearance.
REFERENCES: Ackland HM, Cooper DJ, Malham GM, et al: Factors predicting cervical collar-related decubitus ulceration in major trauma patients. Spine 2007;32:423-428.
Hewitt S: Skin necrosis caused by semi-rigid cervical collar in a ventilated patient with multiple injuries. Injury 1994;25:323-324.

Question 19:

Atraumatic neuropathy of the suprascapular nerve usually occurs at what anatomic location?

Options:

Suprascapular and spinoglenoid notches
Omohyoid muscle
Anterior trapezius muscle
Infraspinatus fascia
Teres minor superior border

Correct Answer: Suprascapular and spinoglenoid notches

Explanation:

Question 20:

Options:

hallux metatarsophalangeal arthrodesis.
custom orthotics.
Chevron osteotomy with second toe correction.
Keller resection arthroplasty with second toe correction.
proximal metatarsal osteotomy with second toe correction.

Correct Answer: proximal metatarsal osteotomy with second toe correction.

Explanation:

Question 21:

What form of fixation is associated with the highest incidence of osseous union when using segmental allograft reconstruction following tumor resection?

Options:

Plate and screw fixation
Fluted intramedullary rods
Interlocking intramedullary rods
Cemented intramedullary rods
Step-cut osteotomies and interlocking intramedullary rods

Correct Answer: Plate and screw fixation

Explanation:

Question 22:

Options:

immobilization.
closed reduction.
open reduction and internal fixation.
early range of motion.
excision.

Correct Answer: immobilization.

Explanation:

Question 23:

Options:

Intraoperative fracture
Deep vein thrombosis
Limb-length discrepancy
Sciatic nerve palsy
Thigh pain

Correct Answer: Limb-length discrepancy

Explanation:

Question 24:

Deep anterior compartment

Options:

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

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

Explanation:

How many compartments exist in the foot:

Question 25:

A surgeon desires to use an implant that will be able to absorb as much energy as possible before it fails. The implant should be made of a material that has which of the following properties?

Options:

A high modulus of elasticity
A low modulus of elasticity
High intrinsic toughness
A high yield stress
Brittleness

Correct Answer: High intrinsic toughness

Explanation:

Question 26:

When evaluating articular cartilage, what extracellular matrix component is most closely associated with the deep calcified cartilage zone?

Options:

Collagen type I
Collagen type II
Collagen type X
Proteoglycan aggrecan
Hyaluronic acid

Correct Answer: Collagen type X

Explanation:

Question 27:

A 22-year-old patient underwent successful reduction of a posterolateral elbow dislocation. Management should now consist of

Options:

splinting for 5 weeks.
active range-of-motion exercises after 1 to 3 days.
delayed passive stretching at 2 weeks.
open medial collateral ligament reconstruction.
open lateral collateral ligament reconstruction.

Correct Answer: active range-of-motion exercises after 1 to 3 days.

Explanation:

Question 28:

The teardrop shape marked with an asterisk in Figure 61 represents what anatomic structure?

Options:

Anterior superior iliac spine
Sciatic buttress
A column of bone running from the anterior inferior iliac spine (AIIS) to the posterior superior iliac spine (PSIS)
The most superior portion of the roof of the acetabulum
Iliopectineal line

Correct Answer: A column of bone running from the anterior inferior iliac spine (AIIS) to the posterior superior iliac spine (PSIS)

Explanation:

DISCUSSION: The teardrop can be visualized on the obturator outlet view of the pelvis and represents a thick column of bone that runs from the AIIS to the PSIS. Half pins for eternal fixation frames or screws can be inserted into this column for fixation of fractures.
REFERENCES: Gardner MJ, Nork SE: Stabilization of unstable pelvic fractures with supra-acetabular compression external fixation. J Orthop Trauma 2007;21:269-273.
Haidukewych GJ, Kumar S, Prpa B: Placement of half-pins for supra-acetabular external fixation: An anatomic study. Clin Orthop Relat Res 2003;411:269-273.
Kim WY, Hearn TC, Seleem O, et al: Effect of pin location on stability of pelvic external fixation. Clin Orthop Relat Res 1999;361:237-244.

Question 29:

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 30:

Options:

closed reduction and a double spica cast.
skeletal traction for 3 weeks, followed by a double spica cast.
reduction and internal fixation crossing the physis if necessary.
reduction and internal fixation with primary bone grafting.
skin traction.

Correct Answer: reduction and internal fixation crossing the physis if necessary.

Explanation:

Question 31:

Options:

Improves the bone mineral density of the vertebral bodies
Reduces the strain at the adjacent intervertebral disk
Reduces the stiffness of the posterior instrumentation
Reduces the strain on posterior instrumentation
Increases the strength of the posterior instrumentation

Correct Answer: Reduces the strain on posterior instrumentation

Explanation:

Question 32:

A 43-year-old woman has had pain in the left hip for the past 2 months. A radiograph, CT scan, MRI scan, and biopsy specimens are shown in Figures 16a through 16e. What is the most likely diagnosis?

Options:

Osteosarcoma
Osteochondroma
Chondrosarcoma
Chordoma
Enchondroma

Correct Answer: Chondrosarcoma

Explanation:

Question 33:

Options:

Technetium Tc 99m bone scan
Intravenous antibiotics
Oral antibiotics
CT of the hips
Aspiration of the left hip

Correct Answer: Technetium Tc 99m bone scan

Explanation:

Examination reveals an irritable hip, creating a differential diagnosis of transient synovitis versus pyogenic hip arthritis. Kocher and associates described four criteria to help predict the presence of infection: inability to bear weight, fever, ESR of more than 40 mm/h, and a peripheral WBC count of more than 12,000/mmP3P. This patient meets three of the four criteria, with a positive predictive value of 73% to 93% for joint infection. Therefore, aspiration of the hip is warranted, with a high likelihood that emergent hip arthrotomy will be indicated. Ideally, intravenous antibiotics should be administered after culture material has been obtained from needle aspiration of the hip. An urgent bone scan is better indicated as a screening test for sacroiliitis or diskitis. If the arthrocentesis proves negative, CT or MRI of the pelvis may be indicated to rule out a pelvic or psoas abscess.
(SBQ13PE.16) A 4-week-old infant who had been born with a dislocated hip has been treated in a Pavlik Harness since 1 week of age. Parents have been compliant with the prescribed bracing protocol, and no complications or neurologic abnormalities have been noted. The hip remains Ortolani positive. Figure A shows the ultrasound image obtained in the office. What is the next best step in management?
Review
Topic
No further treatment
Continue Pavlik Harness treatment
Convert to semi-rigid abduction brace
Perform a hip arthrogram with closed vs. open reduction under general anesthesia
Perform a pelvic osteotomy
This is a 4 week old infant with DDH who has failed Pavlik harness treatment for 3 weeks. Figure A is an ultrasound image demonstrating a dislocated hip.
Initial treatment for an infant with a dislocated, but reducible ("Ortolani positive") hip is bracing in a Pavlik Harness. The Pavlik harness is a dynamic brace that requires normal muscle function and tone to help keep the hip in a reduced position. If this treatment fails to hold the hip reduced after three weeks of treatment, the harness should be discontinued to prevent "Pavlik Harness Disease" which involves erosion of the posterior acetabulum as the femoral head is inappropriately being held against it.
After failure of Pavlik harness treatment, if the hip remains subluxated, the next step in treatment is to convert to a semi-rigid orthosis of another 2-3 weeks. If the semi-rigid brace likewise fails to keep the hip reduced, then hip arthrogram with closed vs. open reduction and spica-cast placement can be planned.
Swaroop and Mubarak present a study using a protocol of initial pavlik harness treatment with weekly ultrasound assessment for 3 weeks. If the hip remained unstable but reducible, then semi-rigid abduction bracing with continues weekly ultrasounds were done for an additional 2-3 weeks. This treatment protocol had a 93% success rate, which compared favorably to protocols not including the abduction
brace.
Hedequist et al. presented a review of 15 patients treated similarly with intial pavlik harness treatment for 3-4 weeks, and then abduction bracing if the remained unstable but reducible. They found that abduction bracing produced a stable hip within 1-2 months.
Illustration A shows a baby wearing a semi-rigid orthosis. Illustration B is the hip ultrasound image from Figure A with labels added. Illustration C is an ultrasound of a hip that is not dislocated.
Incorrect answers:

Question 34:

A patient sustains a severe lower extremity injury. What can be said about his outcome at 2 years if he chooses reconstruction over amputation?

Options:

He has a higher risk of rehospitalization
He has a higher chance of returning to work
He will have a higher overall SIP (Sickness Impact Profile) score
His psychosocial SIP score will improve with time
He will have a better SIP score if he did not complete high school

Correct Answer: He has a higher risk of rehospitalization

Explanation:

Question 35:

Options:

A genetic problem
Repetitive activities involving an open proximal femoral physis
Early closure of the proximal femoral physis
Hip dysplasia

Correct Answer: Repetitive activities involving an open proximal femoral physis

Explanation:

Question 36:

In regards to a genetic disorder, which of the following is an example of "anticipation?"

Options:

Gene characteristics more severe and earlier in onset in subsequent generations
A disorder inherited from a genetic mutation specific to maternal DNA
Gene characteristics expressed to varying degrees in different individuals
Variation in the relative frequency of a genotype due to chance
The presence of an extra copy of a chromosome

Correct Answer: Variation in the relative frequency of a genotype due to chance

Explanation:

Question 37:

At which joint do degenerative changes occur first in a patient with chronic, untreated scapholunate dissociation?

Options:

Radioscaphoid
Radiolunate
Scapholunate
Capitolunate

Correct Answer: Radioscaphoid

Explanation:

EXPLANATION:
Stage I of scapholunate advanced collapse (SLAC) is characterized by the presence of radioscaphoid arthritis. A predictable pattern exists of the progression of degenerative changes for SLAC wrist, including stage I (radial styloid involvement at the scaphoid fossa), stage II (scaphoid and entire scaphoid facet involvement), stage III (degeneration between the capitate and lunate), and stage IV (pancarpal
involvement). The radiolunate joint is often spared.

Question 38:

Options:

axillary neuropathy.
recurrent instability.
shoulder girdle weakness.
luxatio erecta.
biceps tendinitis.

Correct Answer: recurrent instability.

Explanation:

DISCUSSION: Large, displaced anterior inferior glenoid rim fractures predispose patients to recurrent anterior instability due to loss of the normal concavity compression effect of the glenoid. These defects require open reduction and internal fixation to reestablish shoulder stability. Although intra-articular fractures may lead to arthrosis, recurrent instability is
more common.
REFERENCES: Robinson CM, Kelly M, Wakefield AE: Redislocation of the shoulder during the first six weeks after a primary anterior dislocation: Risk factors and results of treatment.
J Bone Joint Surg Am 2002;84:1552-1559.
Bigliani LU, Newton PM, Steinmann SP, et al: Glenoid rim lesions associated with recurrent anterior dislocation of the shoulder. Am J Sports Med 1998;26:41-45.

Question 39:

5cm. Recent radiographs are seen in Figures A and B. What is the most appropriate treatment plan?

Options:

Nail dynamization
Hardware removal, correction of alignment with a Taylor spatial frame, insertion of bone autograft
Exchange unreamed nailing with a longer, larger implant
Augmentative plate fixation without nail removal, insertion of bone autograft
Hardware removal, correction of alignment, plate fixation, insertion of bone autograft

Correct Answer: Nail dynamization

Explanation:

This patient has atrophic non-union (NU) and varus collapse following cephalomedullary nailing of a subtrochanteric fracture. The ideal treatment involves nail removal, correction of alignment, fracture fixation, and bone grafting. Fixation can be achieved with a nail or plate.
Subtrochanteric fractures can be treated with cephalomedullary nailing or fixed angle plates. Nailing of these fractures is technically challenging because the fracture must be reduced prior to nail passage. Failure to do so leads to varus and procurvatum malreduction.
Bellabarba et al. reviewed plating of femoral nonunions after intramedullary nailing. Of 23 nonunions, 21 healed at an average of 12 weeks. The remaining 2 cases required repeat plating (at 2 and 8 weeks) for hardware breakage because of noncompliance with weightbearing restrictions. They advocate plating because it allows for correction of malalignment and provides a biomechanically superior tension band construct.
Incorrect Answers:
OrthoCash 2020
A 38-year-old male was struck by a truck and sustained the injury seen in figure A. Treating this injury with an intramedullary nail with a larger radius of curvature can lead to what complication?
Posterior perforation of the distal femur
Varus malreduction
Comminution of the fracture site
Iatrogenic femoral neck fracture
Anterior perforation of the distal femur
Corrent answer: 5
According to the study by Egol et al, the average femoral anterior radius of curvature was 120 cm (+/- 36 cm), and currently available femoral nails have a greater radius of curvature (i.e. more straight). This mismatch has been shown to lead to an increased risk of perforation of the anterior distal femur as the nail is impacted into the canal.
The referenced study by Tencer et al noted an increased risk of iatrogenic femoral fracture with anterior starting point >6mm from the anatomic axis.
They recommend starting in line with the femoral axis, or just a few millimeters anterior in order to minimize this risk.
Illustration A depicts anterior femoral cortex penetration secondary to nail/femur radius of curvature mismatch.
OrthoCash 2020
A 60-year-old woman is undergoing closed reduction and percutaneous pinning of a proximal humerus fracture. What structure is at greatest risk for injury from the pin marked by the red arrow in Figure A?
Anterior branch of the axillary nerve
Posterior humeral circumflex artery
Long head of the biceps tendon
Cephalic vein
Musculocutaneous nerve
Certain anatomic structures are at risk with percutaneous pinning of proximal humerus fractures. The red arrow in Figure A marks a proximal lateral pin that would place the anterior branch of the axillary nerve at risk.
Rowles and McGrory performed an anatomic study of the structures at risk with closed reduction and percuatneous pinning of the proximal humerus and found that proximal lateral pins were a mean of 3mm from the anterior branch of the axillary nerve. Pins placed through the anterior cortex and directed into the humeral head fragment were a mean of 2mm from the long head of the biceps tendon and greater tuberosity pins were found to be 8mm from the posterior humeral circumflex and 10mm from the main trunk of the axillary nerve as they penetrated the medial cortex of the humerus.
Jaberg et al retrospectively reviewed the clinical and radiographic results of 48 patients at an average of 3 years after undergoing closed reduction and percutaneous pinning of a proximal humerus fracture. 70% good to excellent results with their described technique, and the authors caution that radiographic malunion did not correlate with patient function.
Incorrect Answers
OrthoCash 2020
A 42-year-old female sustains the injury seen in the computed tomography images seen in Figures A and B. According to the Letournel classification, what is the injury pattern shown?
Posterior wall
Transverse
Anterior wall
Posterior column
Both column
The axial CT cut and Judet radiographic view shown reveals a transverse fracture pattern according to the Letournel classification system. This can be determined by the fact that the articular surface of the acetabulum is attached to the intact portion of the ilium, which is connected to the axial skeleton posteriorly through the sacroiliac joint. This differs from a both-column fracture, in which the articular surface of the acetabulum has no attachments to the axial skeleton due to fracture line(s). The axial CT scan also shows a vertical fracture line which is typical of a transverse fracture pattern.
Durkee et al review the classification schemes for these injuries, as well as comment on the importance of quality images (Judet views, CT, etc).
Figures A and B show a transverse acetabular fracture with mild displacement.
OrthoCash 2020
Which of the following is true regarding plating of humeral shaft fractures compared to intramedullary nailing?
worse functional results
higher need for subsequent surgeries
higher incidence of radial nerve injury
lower complication rates
decreased nonunion rates
Corrent answer: 4
Controversy exists regarding nailing compared with plating of humeral shaft fractures, but the most recent and highest level evidence indicates decreased complication rates with open reduction and internal fixation of these injuries.
Lin et al found less blood loss with intramedullary nailing than plating, but nailing was also associated with increased shoulder surgery, likely due to disruption of the rotator cuff tendon during insertion.
Meekers et al found a higher union rate, better functional results and a lower reoperation rate after plate and screw fixation versus nailing. They concluded that plating was superior in most cases of humeral shaft fracture, however more recent studies have challenged these findings.
Heineman et al. (2012) have recently conducted an update on their meta-analysis to include more recent randomized studies. With the inclusion of newer studies the author found a statistically significant increase in total complication rate with the use of IM nailing compared with ORIF. The authors found no significant difference between the two treatment modalities for the secondary outcomes (nonunion, infection, nerve palsy, re-operation)
Incorrect Answers:
OrthoCash 2020
A 35-year-old male sustains the fracture seen in Figures A and B. Which of the following substances has been shown to result in the least radiographic subsidence when combined with open reduction and internal fixation?
Cancellous allograft bone chips
Autograft iliac crest
Femoral intramedullary reamings
Calcium phosphate cement
Calcium sulfate cement
Corrent answer: 4
Figures A and B show a plateau fracture with a lateral split and depression of the articular surface. In treating tibial plateau fractures, calcium phosphate has been shown to have the least amount of articular subsidence on follow-up examinations due to its high compressive strength.
The study by Lobenhoffer et al noted improved radiographic outcomes and earlier weightbearing with usage of calcium phosphate cement. Welch and Zhang reproduced tibial plateau fractures in goats and compared cancellous autograft to calcium phosphate cement augmentation. At 24 hours, four of five specimens treated with autograft had subsidence of the fragment. Only two specimens from limbs treated with cement showed minimal subsidence; the remaining were congruent.
Yetkinler’s study compared cement to no cement treatment in a model of depressed plateau fractures. Calcium phosphate cement of high compressive
strength provided equivalent or better stability than conventional open reduction
and internal fixation with either auto/allograft bone which had both a lower compressive strength and reduced mechanical stability.
OrthoCash 2020
The modified Judet approach to the posterior scapula exploits the internervous interval between what two muscles?
Supraspinatus and infraspinatus
Supraspinatus and subscapularis
Infraspinatus and teres minor
Teres minor and teres major
Teres major and lattisimus
Corrent answer: 3
The posterior or modified Judet approach to the scapula is typically used for internal fixation of scapular fractures. This approach utilizes a transverse incision over the scapular spine with detachment of the posterior deltoid. The interval between the infraspinatus (suprascapular n.) and teres minor (axillary n.) is identified and used to gain access to the posterior aspect of the scapula and glenoid.
The reference by Obremskey et al argues the approach "combines several important goals including: 1) exposure of all bony elements of the scapula which have adequate bone stock for internal fixation; 2) minimal trauma to the rotator cuff musculature; and 3) protection of the major neurologic structures (suprascapular nerve superiorly and axillary nerve laterally)." They believe "the main advantage of the exposure is limiting muscular dissection, which can potentially improve rehabilitation and limit morbidity of the operation."
OrthoCash 2020
An 82-year-old female sustains an intertrochanteric hip fracture and is treated with a sliding hip screw. What is the most appropriate definitive step in treating the failure seen in figure A?
Non-weight bearing
Valgus proximal femoral osteotomy
Total hip arthroplasty
Revision open reduction and internal fixation
Proximal femoral resection
Corrent answer: 3
Figure A shows superior cutout of the lag screw from the sliding hip screw as well as the superior cannulated screw used for an "antirotation" device.
In the referenced review article by Haidukewych and Berry, salvage of failed treatment of hip fractures in the elderly is limited by bone quality and comorbidities. They recommend total hip arthroplasty in this instance to restore function, decrease pain, and limit periods of immobilization. They mention that the major challenges for arthroplasty are: assessing the need for acetabular resurfacing, selecting the femoral implant, and managing the greater trochanter.
OrthoCash 2020
A 13-year-old boy falls out of a tree and sustains the injury seen in Figures A and B. He is taken to the OR for fixation of his fracture.
The next morning, the patient’s blood pressure is 185/105 mm Hg and pulse rate is 130. He complains of pain that is not improved with opiates. On physical exam, the foot is firm. The decision is made to obtain compartment pressures to rule out compartment syndrome of the foot. Which of the following paths in Figure C marks the
appropriate location to measure the central compartment, and what would be considered abnormal values?
Path A, absolute value of 30-45 mmHg or delta p > 30mmHg
Path B, absolute value of 30-45 mmHg or delta p > 30mmHg
Path B, absolute value of 30-45 mmHg or delta p < 30mmHg
Path C, absolute value of 30-45 mmHg or delta p > 30mmHg
Path C, absolute value of 30-45 mmHg or delta p < 30mmHg
Corrent answer: 3
The correct approach to measure pressures in the central compartment of the foot is by directing the needle lateral and plantar through the abductor hallicus, just under the base of the first metatarsal. Abnormal values indicating the need for decompression are an absolute value of 30-45 mmHg or a Δp < 30mmHg (the difference between the patient's diastolic blood pressure and compartment pressures).
The most common symptom of compartment syndrome in the extremities is intense pain. However, compartment syndrome can be difficult to diagnose in children and patients who are comatose, nonverbal, and/or mentally compromised because they may not be able to properly express their level of pain. Additionally, in compartment syndrome of the foot, pain on passive extension of the toes may or may not be present, and swelling and absence of the dorsalis pedis pulse may be expected findings with extensive trauma to the foot, making the clinical diagnosis even more difficult. Thus, for patients with equivocal findings on physical exam, foot compartment pressures should be measured in order to confirm the diagnosis. There are 8 compartments in the foot: lateral, medial, central, and 4 interosseous. The lateral compartment
contains the abductor digiti minimi and flexor digiti minimi brevis, and is measured by directing the needle 1cm medial and plantar under the midshaft of the 5th metatarsal. The medial compartment contains the abductor hallicus and flexor hallicus brevis, and is measured by directing the needle lateral and plantar under the base of the first metatarsal. The central compartment contains the oblique head of the adductor hallucis, and is measured through the same approach as the medial compartment after advancing the needle more deeply. The 4 interosseous compartments entail the 2nd, 3rd, and 4th web spaces, and can be measured by directing the needle plantar into each respective dorsal webspace.
Ojika et al. performed a systematic review on foot compartment syndrome. They found that the most common cause of foot compartment syndrome was crush injury to the foot, and that diagnosis was mostly made through a combination of clinical findings and compartment pressure measurements.
Badhe et al. reported 4 cases where competent sensate patients developed compartment syndromes without any significant pain. They found that pain is not a reliable clinical indicator for underlying compartment syndrome, so in a competent sensate patient, the absence of pain does not exclude compartment syndrome. They concluded that a high index of clinical suspicion must prevail in association with either continuous compartment pressure monitoring or frequent repeated documented clinical examination with a low threshold for pressure measurement.
Flynn et al. looked at the diagnosis and outcome of acute traumatic compartment syndrome of the leg in children. They found that a delay in diagnosis may occur because acute traumatic compartment syndrome manifests itself more slowly in children or because the diagnosis is harder to establish in this age group. They state that the results of the present study should raise awareness of late presentation and the importance of vigilance for developing compartment syndrome in the early days after injury.
Figures A and B are lateral and Harris radiographs of the foot demonstrating a calcaneus fracture. Figure C is a cross-sectional image of the foot. Illustration A is an image depicting the compartments of the foot.
Incorrect Answers:
compartment. Additionally, a Δp < 30mmHg (not > 30mmHg) is considered abnormal.
OrthoCash 2020
A 35-year-old female presents to the emergency room after a motor vehicle collision where her leg was pinned under the car for over 30 minutes. A clinical photo and radiographs are shown. Which of the following is the most accurate way to diagnose compartment syndrome?
surgeon's palpation of the leg compartments
paresthesias in her foot
diastolic blood pressure minus intra-compartmental pressure is less than 30 mmHg
diastolic blood pressure minus intra-compartmental pressure is greater than 30 mmHg
intra-compartmental pressure measurement of 25 mmHg
Corrent answer: 3
The clinical picture is consistent with compartment syndrome. The most accurate way to make the diagnosis is to measure the difference between the diastolic blood pressure and intracompartmental pressure (delta p).
In a prospective study of 116 patients with tibial diaphyseal fractures, McQueen et al found that the use of a differential pressure of 30 mmHg as a threshold for fasciotomy led to no missed cases of acute compartment syndrome. They recommended that a fasciotomy should be performed if the differential pressure level drops to under 30 mmHg.
The cited study by Kakar et al found the intraoperative DBP is significantly lower than the preoperative DBP in patient undergoing IM nailing for tibia shaft
fractures. Therefore, they emphasize that the surgeon should recognize that intraoperative DeltaP may be lower than DeltaP once the patient is awakened in deciding whether to perform a fasciotomy versus awaken the patient and perform serial examinations and or compartment pressure measurements.
An absolute intra-compartmental value greater than 30 to 45mmHg can also be used to make the diagnosis of compartment syndrome, but is more controversial than the delta p according to Kakar and Amendola.
OrthoCash 2020
What is the most common mode of failure of the lateral ulnar collateral ligament associated with an elbow dislocation?
ligament avulsion off the humeral origin
ligament avulsion off the ulnar insertion
midsubstance rupture
bony avulsion of the humeral origin
combined proximal and distal ligament avulsions
Corrent answer: 1
The lateral ulnar collateral ligament (LUCL) is often injured with elbow dislocations, and is most commonly injured at the proximal origin.
McKee noted that in 62 consecutive operative elbow dislocations and fracture/dislocations, the LUCL was ruptured in all of the patients, proximally in 32, bony avulsion proximally in 5, midsubstance rupture in 18, ulnar detachment in 3, ulnar bony avulsion in only 1, and combined patterns in 3.
Pugh et al established a standard protocol to treat elbow fracture dislocations (terrible triad) which includes coronoid repair, radial head repair/replacement, LUCL repair, and MCL and/or external fixation as needed.
OrthoCash 2020
A 24-year-old male sustains the injury seen in Figure A after being thrown from a motorcycle at a high speed. Which of the following fixation methods has been shown to be the most stable fixation construct for this injury?
Posterior bridge plating and anterior ring external fixation
Percutaneous iliosacral screw and anterior ring external fixation
Percutaneous iliosacral screw and anterior ring internal fixation
Transiliac screw
Two percutaneous iliosacral screws
Corrent answer: 3
Figure A shows an APC III injury, which is a rotationally and vertically unstable injury, with damage to the anterior ring, pelvic floor, and posterior ligamentous stabilizing structures.
The referenced study by Sagi et al found that biomechanically, a percutaneous iliosacral screw and anterior ring internal fixation was the most stable construct. In addition, he found no biomechanical support for addition of a second iliosacral screw.
OrthoCash 2020
A 33-year-old male patient presents with a comminuted open tibia fracture after involvement in a motor vehicle crash. He has a history of smoking but is otherwise healthy. He is given antibiotics, and taken immediately for irrigation and debridement, followed by an un-reamed stainless steel intramedullary nail. Due to bone loss there is a non-circumferential cortical defect measuring 12 mm at the fracture site. All of the following factors in this patient's history and presentation increase his risk for adverse outcome EXCEPT:
High-energy mechanism of injury
Use of un-reamed nail
Implant material
Fracture gap
History of smoking
Corrent answer: 2
Of the factors listed only the use of an un-reamed intramedullary nail for an open tibia fracture has not been shown to increase the risk of adverse outcome or need for reoperation.
The treatment of open tibia fractures with intramedullary nailing can be complicated by many factors. High energy mechanism of injury, use of a stainless steel nail, residual fracture gap greater than 1 cm, and a history of smoking have all been shown to increase the risk of adverse outcome. The use of reamed and un-reamed nails for open tibia fractures have been studied, and no significant difference in outcome has been found.
Schemitsch et al. present data from a prospective randomized trial of tibia fractures treated with reamed or unreamed intrameduallry nails. They found no difference in risk of adverse outcome between reamed and un-reamed nails in open tibia fractures. They did, however, find an increased risk of adverse outcomes in high-energy mechanisms, use of stainless steel (versus titanium) rods, and a residual fracture gap of greater than 1 cm. They comment that their data did not show a significant increase in risk due to history of smoking, but cite other studies that have demonstrated such a relationship.
Bhandari et al. present data from a prospective randomized study of patients with tibia fractures randomized to reamed or un-reamed tibial nails. For closed fractures they found a lower rate of primary events (most commonly need for dynamization) in the reamed group. However, they found no difference in outcomes for either technique in open fractures.
Incorrect answers:
OrthoCash 2020
Following antegrade intramedullary nailing of a femoral shaft fracture, the complication shown in Figure A occurs. Which of the following errors most likely resulted in this complication?
Applying external rotation torque on the proximal femur after placing proximal interlocking screws
Excessive interfragmentary compression of the fracture site prior to placing proximal interlocking screws
Using too anterior a starting point for a piriformis-entry point nail
Inserting a trochanteric-entry point nail through the piriformis fossa
Inserting a right femoral nail into the left femur
Corrent answer: 3
Using a piriformis nail, a starting point that is too anterior will result in iatrogenic fracture ("bursting") of the proximal femur.
Antegrade nailing achieves fixation via 3-point fixation. In the sagittal plane, because of anterior sagittal bow, this is achieved at distal anterior cortex, middle posterior cortex (apex of curvature) and proximal anterior cortex. In the coronal plane, because of the lateral bow, this is achieved at the lateral distal femur, middle medial femur (apex of curvature), and proximal lateral femur (greater trochanter). Piriformis nails have a single sagittal bow.
Trochanteric nails are bowed in 2 planes, necessitating a twisting motion during insertion to negotiate both bows.
Papadakis et al. performed an experimental study on 18 cadaveric femora. Anterior bursting was found in 56% of nails placed too anteriorly. Bursting was not seen in nails placed through a more posterior entry point. They emphasize the location of the entry point when performing antegrade nailing.
Johnson et al. reviewed the biomechanical factors affecting fracture stability
and femoral bursting. They found that position of the starting hole was most important. Anterior displacement by >6mm led to high hoop stresses and bursting of the anterior cortex. This is important as an eccentrically reamed cortex may be difficult to recover from. They recommend either selecting a smaller diameter nail or overreaming by 1-2mm as a solution.
Figure A shows a fracture split of the proximal femur (left, without magnification; right, close-up). Illustration A shows anterior cortex pressures exceeding 100kPa for too-anterior entry points.
Incorrect Answers:
Wrong-side placement of a trochanteric entry nail would lead to varus malalignment at the fracture site, more so than placing a piriformis nail through the greater trochanter.
OrthoCash 2020
A 30-year-old male sustains a brachial plexus injury as the result of a motor vehicle collision. Palsy of which of the following muscles would not be expected with this injury if the injury was postganglionic in nature?
Rhomboid major
Extensor carpi radialis longus
Biceps brachii
Deltoid
Brachioradialis
A brachial plexus injury would involve all of the upper extremity muscles as well as most of the periscapular muscles. Complete plexus palsies are rare, and are often associated with scapulothoracic dissociation or other high-energy injuries.
Preganglionic injuries often involve the cervical paraspinal musculature as well as a complete plexus injury. EMG evidence of intact signals in the serratus anterior (long thoracic nerve) and rhomboids (dorsal scapular nerve) are suggestive of a postganglionic lesion/injury.
Tubbs et al. reported on the surgical anatomy of the dorsal scapular nerve in a cadaver study. They found that the nerve came off the C5 nerve root in 95%, ran 2.5cm medial to the spinal accessory nerve as it traveled on the anterior border of the trapezius muscle, and was intertwined with the dorsal scapular artery in all specimens.
Balakrishnan et al reported on the comparison of clinical exam and EMG in predicting site of lesions in brachial plexus injuries. The combination of EMG and exam localized the nerve injury in 80%, while the paraspinal EMG was the most sensitive solitary examination method (67%).
Illustration A shows a diagram of the brachial plexus. Incorrect Answers:
5: These muscles are all innervated by nerves that come from the brachial
plexus, and would be affected with a postganglionic injury.
OrthoCash 2020
A 40-year-old male sustains a fall from a height. He sustains the isolated injury shown in the radiograph and CT images seen in Figures A through C. Surgery is planned. Which of the following constructs is the most appropriate definitive fixation for this injury?
Lateral locked plating
Medial bridge plating
Medial buttress plate
Medial lag screw with washers
External fixation
This patient has a medial tibial plateau fracture. Medial buttress plating (MBP) is indicated.
Medial tibial plateau fractures (Schatzker IV, Hohl and Moore II) may represent fracture dislocations of the knee. Neurovascular injuries must be excluded. In these instances, the medial fragment represents the stable fragment, and the rest of the tibia is the fractured fragment, with the entire leg acting as the lever arm.
Berkson et al. reviewed high energy tibial plateau fractures. Medial fractures may be treated with a medial plate or external fixation. Open reduction may be necessary because of fracture line obliquity and propensity of the medial plateau to shorten and rotate in the sagittal plane. Meniscal injuries should be repaired and avulsed cruciates fixed early. Collateral ligaments should be reconstructed after obtaining bone healing and range of motion.
Ratcliff et al. compared the stability of lateral locked plates and medial buttress plates in a cadaver model. They found that the medial buttress plate had greater fixation strength/failure force (4136N) compared with the lateral locking plate (2895N), although maximum cyclic displacement and residual displacement results were not different. They concluded that for vertically
orientated medial tibial plateau fractures, medial buttress plates were more stable.
Figure A is a radiograph showing a medial tibial plateau fracture extending across the tibial eminence. This is also classified as a Hohl and Moore Type II fracture. Figures B and C are coronal and axial CT scan images confirming the medial tibial plateau fracture and excluding a bicondylar fracture. Illustration A shows a medial tibial plateau fracture fixed with a medial buttress plate (cadaveric model with fibula removed). Illustration B shows the Hohl and Moore Type II fracture involving the entire condyle.
Incorrect Answers:
OrthoCash 2020
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?
Weakness of hip flexion
Weakness of ankle dorsiflexion
Numbness of the medial thigh
Numbness of the lateral thigh
Numbness of the perineum
Corrent answer: 4
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:
OrthoCash 2020
What would be the most appropriate surgical indication for transferring fascicles of the ulnar nerve to the motor nerve of the biceps and fascicles of the median nerve to the motor nerve of the brachialis?
C8 - T1 nerve root avulsion 3 months ago
C5 - C6 nerve root avulsion 2 months ago
Upper brachial plexus palsy 22 months ago
Medial and posterior cord injury from gunshot wound 2 months ago
C6 ASIA A spinal cord injury
Corrent answer: 2
Transfer of fascicles from (1) ulnar nerve to the nerve to the biceps and (2) median nerve to the motor nerve of the brachialis would be appropriate in the
treatment of an acute (<3-6 months) upper brachial plexus palsy.
Upper trunk injury (C5, C6) often results from the avulsion of both the C5 and C6 nerve roots. Injuries of this nature usually result from a downward force on the shoulder with lateral bending of the cervical spine in the opposite direction. This results in what is commonly called an Erb-Duchenne palsy. Patients often present with a flail shoulder and loss of elbow flexion. Other common treatments for C5 and C6 root avulsion include neurotization of the musculocutaneous (MSC) nerve by the spinal accessory (SA) or intercostal nerve, and neurotization of the supra-scapular nerve by the SA.
Liverneaux et al. looked at short term results of (1) ulnar nerve fascicle transfer to the nerve to the biceps and (2) fascicle of the median nerve to the motor branch to the brachialis in 15 patients with acute C5 - C6 nerve root avulsion injuries. Grade 4 elbow flexion was restored in each of the 10 patients. There was no secondary deficit in grip strength or sensation.They concluded that this double nerve transfer technique will likely reduce the need for secondary procedures to augment elbow flexion.
Teboul et al. reviewed thirty-two patients with an upper nerve-root brachial plexus injury that underwent ulnar nerve fascicle transfer to the nerve of biceps to restore elbow flexion. After the nerve transfer, twenty-four patients achieved grade 3 elbow flexion strength or better. They note that this procedure will spare the C5 nerve root and other nerves for grafting or transfer elsewhere.
Illustration A shows harvesting of an ulnar nerve fascicle for transfer. Illustration B shows transfer of the fascicle of the ulnar nerve to the motor nerve of the biceps.
Incorrect Answers:
sensory quadriplegia. Nerve transfers using the ulnar nerve (C8-T1) would also be redundant as this nerve would be non-functional in this patient.
OrthoCash 2020
A 31-year-old female presents to the trauma bay following a motorcycle crash. Her blood pressure is 95/70 mmHg, heart rate is 115 bpm. Lactate measured in the trauma bay is 10 mmol/L. She has multiple rib fractures, pulmonary contusions, and a positive FAST exam requiring immediate exploratory laparotomy. After laparotomy her lacate remains unchanged. She has a closed right femur fracture and an open right tibia fracture as seen in Figures A and B. Besides antibiotics and thorough irrigation and debridement, which of the following would be an appropriate step in the immediate management of her fractures?
Reamed intramedullary nailing of the tibia and femur
Un-reamed intramedullary nailing of the tibia, and reamed intramedullary nailing of the femur
Reamed intramedullary nail of the tibia, and un-reamed intramedullary nail
of the femur
Posterior slab splint of the tibia, and 10 lbs skeletal traction of the femur
External fixation of the tibia and femur
Corrent answer: 5
This patient is suffering from multiple injuries and has evidence of chest injury and incomplete resuscitation. The immediate treatment of her fractures should be external fixation for both the tibia and the femur.
For polytraumatized patients with multiple injuries including extremity fractures, damage control orthopaedics dictates that long bone fractures should be temporarily stabilized. Either inadequate stabilization, or early total care, such as a reamed or unreamed nails, can exacerbate the patient's condition and increase the risk of a second-hit phenomenon. For this patient with pulmonary contusions and continued elevation of lactate indicating end-organ hypoperfusion her extremities should have staged treatment according to damage control principles.
Morshed et al. present a retrospective review of polytraumatized patients with femur fractures and compared outcomes based on the time frame in which their fractures were definitively treated. They found delaying treatment at least 12 hours to allow appropriate resuscitation and treatment of other traumatic injuries led to a decrease in mortality of 50%. Patients with intra-abdominal injuries benefited most from staged treatment of the extremities.
Figure A is a radiograph showing a closed right femur fracture. Figure B is a radiograph of an open right tibia fracture.
Incorrect answers:
OrthoCash 2020
A 68-year-old woman undergoes a hemiarthroplasty for a proximal humerus fracture through a deltopectoral approach. What
range of motion exercise should not be utilized in the immediate postoperative period due to concerns about lesser tuberosity fixation?
Pendulums
Passive internal rotation of the shoulder to the plane of the body
Active forearm supination
Passive external rotation of the shoulder past 30 degrees
Passive forward flexin of the shoulder to 90 degrees
Corrent answer: 4
Frankle et al found that passive external rotation of the shoulder placed the most stress on the lesser tuberosity fixation. The subscapularis tendon inserts on the lesser tuberosity and is the deforming force when placed under tension during external rotation. They also found that non-anatomic tuberosity reduction of 4-part proximal humerus fractures treated with hemiarthroplasty increased torque and impaired external rotation kinematics.
OrthoCash 2020
A 72-year-old female sustains a displaced intracapsular femoral neck fracture. Which of the following is TRUE regarding the long term differences between possible treatment options for this injury?
Patients undergoing total hip arthroplasty are more likely to experience persistent pain than those undergoing internal fixation
Patients undergoing total hip arthroplasty are less likely to require reoperation than those undergoing internal fixation
There is no difference in functional outcome scores between internal fixation and total hip arthroplasty
Patients undergoing internal fixation perform activities of daily living better than those undergoing total hip arthroplasty
Mortality rates are higher following total hip arthroplasty than internal fixation
Elderly patients with femoral neck fractures (FNF) undergoing total hip arthroplasty (THA) are less likely to require reoperation than those undergoing internal fixation.
Intracapsular FNF are common in elderly patients after a fall from standing height. Treatment depends on physiological age and displacement (Garden's classification). For displaced fractures, physiologically young patients are treated with internal fixation while physiologically old patients are treated with
either hemiarthroplasty (debilitated, less active patients) or THA (more active patients, those with acetabular disease or preexisting inflammatory arthritis).
Chammout et al. retrospectively compared the long term (17 years) results of THA (cemented both component) and ORIF (2 cannulated screws) in elderly patients (>65 years). They found no difference in mortality. But hip scores were higher and pain was better in the THA group, while reoperation rates were higher in the ORIF group. Walking speed was initially faster in the THA group, but later did not differ between groups. They recommend THA for elderly patients with displaced FNF.
Rogmark et al. prospectively compared closed reduction and internal fixation (CRIF) with arthroplasty (combining hemiarthroplasty and THA) at 2 years in elderly patients (>70 years). Failure rates were higher, pain was worse, and walking was more impaired after CRIF. They recommend arthroplasty for patients >70 with FNF.
Incorrect Answers:
OrthoCash 2020
A polytrauma patient underwent the following procedures: (1) statically locked intramedullary nailing for a right femoral shaft fracture; (2) open reduction with plate-and-screw fixation [ORIF] for a right simple distal fibula fracture; (3) ORIF right middle third radius and ulna fracture; and (4) ORIF left humeral shaft fracture. What is the appropriate weightbearing status for this patient?
Weight bearing as tolerated in all extremities
Early protected weight bearing right lower extremity in walking cast, weight bearing as tolerated left upper extremity, non-weight bearing right forearm
Weight bearing as tolerated in bilateral lower extremities and right upper extremity, non-weight bearing left upper extremity
Non-weight bearing bilateral upper extremities and right lower extremity
Non-weight bearing right upper and lower extremities, weight bearing as tolerated left upper and lower extremities without walking cast
The standard postoperative weightbearing for locked medullary nailing for femoral shaft fractures and humeral shaft fractures is weight bearing as tolerated (WBAT). Simple ORIF ankle fractures may be managed with early protected weight bearing. ORIF right middle third radius and ulna fracture should be managed with a period of non-weight bearing due to risk of secondary displacement of the fracture.
Tingstad et al. examined the effect of immediate weightbearing on plated fractures of the humeral shaft. They reported that immediate weightbearing on humeral shaft fractures, treated with plating and full weightbearing, did not have any negative effect on the union or malunion rates.
Brumback et al. evaluated the feasibility, safety and efficacy of immediate weightbearing after treatment of femoral shaft fractures with statically locked IM nail. Using biomechanical and clinical data, they showed that all fractures united with no loss of fixation or hardware failure.
Starkweather et al. retrospectively assessed the complications and loss of reduction in patients who bore weight in a short leg cast within 15 days after surgical repair of acute unilateral closed ankle fractures. Of the 81 ankle fracture radiographs, 80 (98.8%) showed no displacement in fracture reduction on the final follow-up examination. These results suggest early protected weightbearing may be safe.
Incorrect Answers:
OrthoCash 2020
A 22-year-old female falls off the back of a motorcycle and sustains the injury in Figure A. She is hemodynamically unstable and massive transfusion protocol is activated. What is the correct ratio of transfusion of packed red blood cells, platelets and plasma?

Question 40:

Options:

2 to 5 days, followed by initiation of assisted motion.
14 to 21 days, followed by initiation of assisted motion.
4 weeks, followed by active motion.
6 weeks, followed by physical therapy.
8 weeks, followed by active motion of the elbow.

Correct Answer: 2 to 5 days, followed by initiation of assisted motion.

Explanation:

Question 41:

- Which of the following factors is most likely to predispose a patient to dislocation of the patellar component following total knee arthoplasty?

Options:

Internal rotation of the femoral component
External rotation of the tibial component
Lateral placement of the femoral component
Medial placement of the patellar component
Excessive resection of the patella

Correct Answer: Internal rotation of the femoral component

Explanation:

Question 42:

Options:

MRI
Surgical intervention
Activity modification
Cast immobilization

Correct Answer: Activity modification

Explanation:

Question 43:

Options:

Extensor pollicis longus (EPL) tendon
Adductor aponeurosis
EPB and dorsal capsule
Ulnar sesamoid bone and volar plate

Correct Answer: Adductor aponeurosis

Explanation:

Question 44:

In the treatment of rheumatoid arthritis, which medication is an antagonist of tumor necrosis factor-alpha?

Options:

Rituximab
Etanercept
Abatacept
Methotrexate
Leflunomide

Correct Answer: Etanercept

Explanation:

Question 45:

Radiographs of a pediatric patient reveal a suspected osteosarcoma of the distal femur. Additional staging studies should consist of

Options:

a radiograph and CT of the chest and a bone scan.
a radiograph and MRI of the primary tumor.
CT of the abdomen and pelvis.
CT of the abdomen, chest, and pelvis, radiographs of the chest and primary tumor, MRI of the primary tumor, and a bone scan.
CT of the chest, radiographs of the chest and primary tumor, MRI of the primary tumor, and a bone scan.

Correct Answer: CT of the chest, radiographs of the chest and primary tumor, MRI of the primary tumor, and a bone scan.

Explanation:

Question 46:

Options:

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

Correct Answer: Brachial neuritis

Explanation:

Question 47:

Glenohumeral disarticulation often leads to which of the following changes?

Options:

Hiking of the shoulder girdle
Hypertrophy of the amputated shoulder girdle
Improvement in thoracic spinal deformity
Protraction of the shoulder
Winging of the scapula

Correct Answer: Hiking of the shoulder girdle

Explanation:

Question 48:

- A 13-year-old quarterback feels a “pop” in his knee while being tackled. Radiographs of the knee and results of a Lachman’s test are normal. Examination reveals tenderness over the distal femoral physis. To help confirm the diagnosis, management should first include

Options:

an MRI scan
arthroscopic examination
AP and frog-lateral radiographs of the pelvis and hips
varus and valgus stress radiographs of the knee
physical examination of the knee under anesthesia

Correct Answer: varus and valgus stress radiographs of the knee

Explanation:

Question 49:

Options:

Volar scapholunate interosseous
Dorsal scapholunate interosseous
Long radiolunate
Short radiolunate
Dorsal intercarpal

Correct Answer: Dorsal scapholunate interosseous

Explanation:

DISCUSSION: The radiographs reveal a gap between the scaphoid and lunate bones, indicative of disruption of the scapholunate ligament complex. The three components of the complex are the dorsal scapholunate ligament, the volar (or palmar) scapholunate ligament, and the proximal fibrocartilaginous membrane, listed in decreasing yield strength. Disruption of the stout dorsal interosseous ligament is required for scapholunate dissociation to occur.
REFERENCES: Berger RA: The ligaments of the wrist: A current overview of anatomy with considerations of their potential functions. Hand Clin 1997;13:63-82.
Cohen MS, Taleisnik J: Direct ligamentous repair of scapholunate dissociation with capsulodesis augmentation. Tech Hand Up Extrem Surg 1998;2:18-24.

Question 50:

Options:

CT scan
Hybrid external fixation
Ankle-spanning external fixation
Open reduction and internal fixation within 6 to 8 hours
Open reduction and internal fixation within 2 to 3 days

Correct Answer: Ankle-spanning external fixation

Explanation:

Question 51:

Options:

Open biopsy
Needle aspiration
Arthroscopy
CT
Arthrography

Correct Answer: Needle aspiration

Explanation:

Question 52:

preservation of the radioscaphocapitate ligament, the most radial of the palmar extrinsic ligaments, which prevents ulnar subluxation after proximal row carpectomy.

Options:

The arrows in the axial T 1 -weighted MRI scan shown in Figure 25 show which of the following structures?
Ulnar artery and accompanying vein
Deep and superficial branches of the ulnar nerve
Radial and ulnar digital nerves to the little finger
Palmar cutaneous and thenar motor branch of the median nerve
Dorsal cutaneous branch of the ulnar nerve and common digital artery to the fourth web

Correct Answer: The arrows in the axial T 1 -weighted MRI scan shown in Figure 25 show which of the following structures?

Explanation:

The arrows in the figure show the deep branch of the ulnar nerve (more radial) and the superficial branch of the ulnar nerve within Guyon’s canal. Guyon’s canal is approximately 4 cm long beginning at the proximal extent of the transverse carpal ligament and ends at the aponeurotic arch of the hypothenar muscles. Many structures comprise the boundaries of Guyon’s canal. The floor, for example, consists of the transverse carpal ligament, the pisohamate and pisometacarpal ligaments, and the opponens digiti minimi. Within Guyon’s canal, the ulnar nerve bifurcates into the superficial and deep branches. The ulnar artery is immediately adjacent and radial to the ulnar nerve. The median nerve is visualized within the carpal tunnel, and the palmar cutaneous branch is more radial to Guyon’s canal and volar to the carpal tunnel. The radial and ulnar digital nerves to the little finger are branches off of the superficial branch of the ulnar nerve distal to its emergence from Guyon’s canal. The ulnar artery is the round structure located radial to the branches of the ulnar nerve within Guyon’s canal. Adjacent to the ulnar artery are two small veins. The dorsal cutaneous branch of the ulnar nerve branches from the ulnar nerve in the distal forearm, well proximal to Guyon’s canal. The common digital artery to the fourth web branches from the superficial palmar arch distal to Guyon’s canal. The hook of the hamate is clearly seen in the figure, orienting the observer to the ulnar side of the wrist
A 37-year-old patient with type I diabetes mellitus has a flexor tenosynovitis of the thumb flexor tendon sheath following a kitchen knife puncture wound to the volar aspect of the thumb. Left unattended, this infection will likely first spread proximally creating an abscess in which of the following spaces of the palm?
Central space
Hypothenar space
Carpal tunnel
Posterior adductor space
Thenar space
CORRECT ANSWER: 5
Flexor tenosynovitis of the thumb flexor tendon sheath can spread proximally and form an abscess within the thenar space of the palm. The flexor pollicis longus tendon does not pass through the central space of the palm or the hypothenar space of the palm. The flexor pollicis longus tendon does pass through the carpal tunnel, but this is not a palmar space. The three palmar spaces include the hypothenar space, the thenar space, and the central space. The posterior adductor space would likely only be involved secondarily after spread from a thenar space infection.
New painful paresthesias near the site of the incision after an ulnar nerve transposition is the result of injury to what nerve?
Medial antebrachial cutaneous
Lateral antebrachial cutaneous
Posterior antebrachial cutaneous
Medial brachial cutaneous
Dorsal antebrachial cutaneous
Branches of the medial antebrachial cutaneous nerve can often be identified during routine ulnar nerve surgery crossing the medial aspect of the elbow. It should be preserved to avoid development of painful paresthesias.
A 21-year-old man who was injured in a snowboarding accident 18 months ago now reports wrist pain. An MRI scan is shown in Figure

Question 53:

Options:

Neurogenic pain
Bone overgrowth
Hip flexion contracture
Hip adduction contracture
Leg length inequality

Correct Answer: Leg length inequality

Explanation:

Question 54:

Options:

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

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

Explanation:

Question 55:

Options:

Return to full soccer activity
Start light aerobic activity
Obtain baseline neuropsychological testing
MRI scan of the brain

Correct Answer: Start light aerobic activity

Explanation:

Question 56:

A 1-year-old infant has the hand deformities shown in Figure 40. What pathologic process is the most likely cause of these deformities?

Options:

Genetic mutation
Teratogen exposure
Amniotic rupture
Iatrogenic influences
Developmental field disruption

Correct Answer: Amniotic rupture

Explanation:

Question 57:

Options:

increased strength of the rotator cuff repair by creating thicker repair construct.
decreased size of the defect exposing the humeral head.
decreased stress in the rotator cuff at the site of the side-to-side repair.
decreased stress in the rotator cuff at the free margin and greater tuberosity interface.
decreased stress in the rotator cuff crescent cable.

Correct Answer: decreased stress in the rotator cuff at the free margin and greater tuberosity interface.

Explanation:

Question 58:

Options:

Erythrocyte sedimentation rate, C-reactive protein, and white blood cell count
Serum cobalt and chromium ion levels
MRI with metal artifact reduction sequence (MARS)
CT of pelvis

Correct Answer: MRI with metal artifact reduction sequence (MARS)

Explanation:

Question 59:

Options:

Lead to lower patient satisfaction rates
Lead to higher patient satisfaction rates
Lead to higher likelihood the patient will take legal action against surgeon
Lead to higher likelihood the patient will change physicians
Prevent any legal action

Correct Answer: Lead to lower patient satisfaction rates

Explanation:

Question 60:

Acral metastases are most commonly seen in what type of carcinoma?

Options:

Renal cell
Lung
Thyroid
Breast
Ovarian

Correct Answer: Lung

Explanation:

DISCUSSION: Metastatic lesions to bone are usually located in the axial and proximal appendicular skeleton. Metastases below the elbow and knee are rare, but when they do occur they are most commonly from lung carcinoma.
REFERENCES: Hayden RJ, Sullivan LG, Jebson PJ: The hand in metastatic disease and acral manifestations of paraneoplastic syndromes. Hand Clin 2004;20:335-343.
Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 313.

Question 61:

Options:

Glenoid bone loss of 10%
Capsular attenuation from prior thermal capsulorraphy
Anterior labral periosteal sleeve avulsion (ALSPA ) lesion
Glenoid labral articular defect (GLAD) lesion
Combined Superior Labrum from Anterior to Posterior tear (SLAP) and recurrent Bankart lesion

Correct Answer: Glenoid bone loss of 10%

Explanation:

Question 62:

Options:

posterior; flexor carpi radialis
posterior; flexor carpi ulnaris
posterior; flexor digitorum superficialis to the long finger
mobile wad; flexor carpi radialis
mobile wad; flexor carpi ulnaris

Correct Answer: mobile wad; flexor carpi ulnaris

Explanation:

Question 63:

When treating osteoporosis with alendronate, what is the most common side effect?

Options:

Diarrhea
Epigastric distress
Dry mucous membranes
Drowsiness
Insomnia

Correct Answer: Epigastric distress

Explanation:

Question 64:

Options:

Long-arm cast
Percutaneous screw fixation
Open reduction and internal fixation (ORIF) with bone graft
Proximal row carpectomy

Correct Answer: Open reduction and internal fixation (ORIF) with bone graft

Explanation:

Question 65:

Which of the following factors can contribute to patellar subluxation following routine total knee arthroplasty?

Options:

External rotation of the femoral component
Internal rotation of the tibial component
Symmetric patellar resection
Lateral placement of the tibial component
Neutral alignment of the mechanical axis

Correct Answer: Internal rotation of the tibial component

Explanation:

Question 66:

Options:

Split-thickness skin graft
Full-thickness skin graft
Soleus rotation flap
Medial gastrocnemius rotation flap
Free latissimus dorsi flap with microvascular anastomosis

Correct Answer: Free latissimus dorsi flap with microvascular anastomosis

Explanation:

Question 67:

Options:

radiation therapy and chemotherapy.
surgical drainage and antibiotics.
surgical excision with chemotherapy and/or radiation therapy.
proximal femoral resection, allograft prosthetic reconstruction, and chemotherapy.
serial observation with repeat MRI in 3 months.

Correct Answer: surgical excision with chemotherapy and/or radiation therapy.

Explanation:

Question 68:

Options:

Discoid lateral meniscus
Congenital absence of the anterior cruciate ligament
Torn medial meniscus
Osteomyelitis of the distal femur DISCUSSION A discoid lateral meniscus is probably the most common cause of a symptomatic clicking or clunking in the knee in a young child. This is a congenital problem that can become symptomatic as soon as a child ambulates, or the condition may remain asymptomatic for several years. The meniscus develops from a cartilaginous anlage and at no point in its development is it discoid. The MRI scans reveal a band of meniscal tissue filling the joint’s lateral compartment on both sagittal and coronal images. A medial meniscal tear is usually accompanied by a history of injury and an effusion, which are not present in this child. There is also no joint line tenderness, which makes this diagnosis less likely. Congenital absence of the anterior cruciate ligament may be found in children born with congenital knee hyperextension, which is ruled out in this case by normal history and examination findings. Children with osteomyelitis are often systemically ill. On examination, they may have warmth and tenderness. MRI scans will often show an area of increased signal on T1-weighted images.

Correct Answer: Discoid lateral meniscus

Question 69:

Following a vertebroplasty of L2, cement is noted to protrude directly anterior to the L2 vertebral body. The cement is closest to which of the following structures?

Options:

Inferior vena cava
Pancreas
Duodenum
Left lobe of the liver
Descending aorta

Correct Answer: Descending aorta

Explanation:

DISCUSSION: At the level of L2, the liver and the vena cava lie to the right. The pancreas
and duodenum are anterior to the aorta. The aorta lies in the midline just in front of the
vertebral body.
REFERENCES: Clement CD: Anatomy: A Regional Atlas of Human Anatomy, ed 3.
Baltimore, MD, Munich, Germany, Urban and Schwarzberg, 1987, Figure 331.
Netter FH: Atlas of Human Anatomy. Summit, NJ, Ciba-Geigy, 1989, plate 328.

Question 70:

What is the most appropriate treatment for a chordoma involving the sacrum?

Options:

Chemotherapy
External beam radiation therapy
En bloc surgical resection with negative margins
Intralesional resection followed by radiation therapy
Intralesional resection followed by chemotherapy

Correct Answer: En bloc surgical resection with negative margins

Explanation:

Question 71:

Options:

anterior cruciate ligament reconstruction with lateral meniscus repair.
partial lateral meniscectomy with saucerization.
lateral meniscus transplant.
protected weight bearing with referral for genetic testing.

Correct Answer: partial lateral meniscectomy with saucerization.

Explanation:

The MR images show a tear through a discoid lateral meniscus. A discoid meniscus is caused by a failure of apoptosis during development in utero and is considered a congenital abnormality. Discoid menisci are prone to tearing and can be caused by minimal trauma. There is no known genetic cause for this condition. Radiographic findings that may be present in the setting of a discoid meniscus include lateral joint space widening, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Contralateral discoid menisci are noted in 20% of patients. There are no other known associated conditions. Treatment
of a symptomatic discoid meniscus should include partial meniscectomy and saucerization or repair.

Question 72:

Based on the appearance of the imaging studies shown in Figures 11a through 11c, what structure has most likely been injured?

Options:

Quadriceps tendon
Medial collateral ligament
Medial patellofemoral ligament
Anterior cruciate ligament
Lateral retinaculum

Correct Answer: Medial patellofemoral ligament

Explanation:

Question 73:

Options:

Remove fixation and repeat vascular exam
Add a medial pin, remove two of the lateral pins and repeat vascular exam
Maintain hardware position, apply a soft dressing and observe
Maintain hardware position, apply long arm immobilization and observe
Surgically explore the antecubital fossa

Correct Answer: Remove fixation and repeat vascular exam

Explanation:

Question 74:

Options:

Repeat neurolysis of the common peroneal nerve at the knee level
Repeat neurolysis of the common peroneal nerve with cable grafting
Extensor hallucis longus transfer to the distal first metatarsal
Anterior transfer of the tibialis posterior tendon through the interosseous membrane
Ankle fusion

Correct Answer: Anterior transfer of the tibialis posterior tendon through the interosseous membrane

Explanation:

DISCUSSION: The ankle dorsiflexor muscles have been denervated for too long a period to expect reinnervation to be successful. Even if the extensor hallucis longus tendon was functional, it is unlikely to have sufficient strength to achieve dynamic ankle dorsiflexion. The tibialis posterior tendon transfer has been shown to predictably achieve these goals in a high percentage of patients. Successful ankle fusion is likely to fail with time due to the development of forefoot equinus.
REFERENCES: Pinzur MS, Kett N, Trilla M: Combined anteroposterior tibial tendon transfer in post-traumatic peroneal palsy. Foot Ankle 1988;8:27l-275.
Lipscomb P, Sanchez J: Anterior transplantation of the posterior tibial tendon for persistant palsy of the common peroneal nerve. J Bone Joint Surg Am 1961;43:60-66.

Question 75:

Options:

Biopsy of the soft-tissue mass
Epidural corticosteroid injection into the lumbar spine
Four-compartment fasciotomy of the leg
Fascial release and neurolysis of the superficial peroneal nerve
Closure of the fascial defect of the superficial peroneal nerve

Correct Answer: Fascial release and neurolysis of the superficial peroneal nerve

Explanation:

Question 76:

What is the most common complication associated with open reduction and internal fixation using a 90/90 plate configuration and olecranon osteotomy for an OTA type C2 distal humerus fracture?

Options:

Nonunion of the lateral column
Nonunion of the medial column
Nonunion of the olecranon osteotomy
Pain related to the plates
Pain related to the olecranon fixation

Correct Answer: Pain related to the olecranon fixation

Explanation:

Question 77:

Options:

extra-articular ligament repair.
resection arthroplasty with a cement spacer.
revision of the tibial tray.
revision of the patella to an all-polyethylene component.
revision to a posterior cruciate-substituting implant.

Correct Answer: revision to a posterior cruciate-substituting implant.

Explanation:

Question 78:

Options:

The flexor digitorum longus tendon is ruptured.
The posterior tibial tendon has a normal appearance.
The posterior tibial tendon has a physiologic amount of fluid in its sheath.
The posterior tibial tendon is completely ruptured and retracted (type III tear).
The posterior tibial tendon has a chronic longitudinal split with enlargement (type II tear).

Correct Answer: The posterior tibial tendon has a chronic longitudinal split with enlargement (type II tear).

Explanation:

Question 79:

A 57-year-old man has had right ankle pain for the past 10 months following an injury that went untreated. Radiographs are shown in Figures 30a through 30c. Management should consist of

Options:

ankle arthrodesis.
modified Brostrom ligament reconstruction.
restoration of fibular length, alignment, and rotation.
cast immobilization.
tibial shortening osteotomy.

Correct Answer: restoration of fibular length, alignment, and rotation.

Explanation:

Question 80:

Options:

excision of heterotopic bone.
hardware removal and elbow joint release with splinting.
semiconstrained total elbow arthroplasty.
distraction arthroplasty.
synovectomy and radial head excision.

Correct Answer: hardware removal and elbow joint release with splinting.

Explanation:

Question 81:

- Figures 38a & 38b show radiographs of a 40 year old man who underwent a Putti-Platt repair for recurrent dislocations at age 22. He reports increasing pain in the shoulder and limited motion for five years. Examination reveals 130 degrees of elevation and 15 degrees of external rotation. Non-surgical treatment has failed. Treatment should now consist of what?

Options:

Manipulation Under Anesthesia
Arthroscopic acromioplasty
Arthroscopic debridement of G-H joint
Replacement of the humeral head
Lengthening of the subscapularis and release of the anterior capsule

Correct Answer: Lengthening of the subscapularis and release of the anterior capsule

Explanation:

Question 82:

Options:

MRI/arthrogram of the right shoulder
CT of the right proximal humerus
Bone biopsy of the right proximal humerus
Cessation of throwing for 6 to 8 weeks, followed by a progressive throwing program
Arthroscopic evaluation of the right shoulder

Correct Answer: Cessation of throwing for 6 to 8 weeks, followed by a progressive throwing program

Explanation:

Question 83:

The function of which of the following structures is to resist internal tibial rotation with the knee in full extension? Review Topic

Options:

Anterior cruciate ligament
Iliotibial band
Popliteus tendon
Popliteofibular ligament
Posterior oblique ligament

Correct Answer: Posterior oblique ligament

Explanation:

Question 84:

Options:

Gender
Age
Race
Environment

Correct Answer: Race

Explanation:

Question 85:

Options:

ACL reconstruction 20 years ago
Spontaneous osteonecrosis of the knee involving the medial compartment
A history of inflammatory arthritis
Body weight of 80kg
degree varus deformity Corrent answer: 3 Inflammatory arthritides are considered contraindications for a partial knee replacement due to the likely progression of arthritis in the native compartments. Unicompartmental arthroplasty (UKA) is generally considered an excellent procedure provided that appropriate surgical indications are used for patient selection. Classic indications for UKA include unicompartmental disease in patients older than 60 with relatively low activity demands. Additionally, the patients should weigh less than 82 kg, have minimal pain at rest, have motion >90 degrees, varus deformity <10 degrees, and flexion contractures <10 degrees. While most of these classic indications are still used today, recent studies are showing excellent results in younger, heavier, and more active patients. Inflammatory arthropathy is a contra-indication to unicompartmental knee replacement due to the high risk of continued arthritis progression in the other compartments. These patients should undergo total knee replacement instead. Heyse et al. retrospectively reviewed the results of unicompartmental arthroplasty for spontaneous osteonecrosis of the knee (SONK). 75.7% of patients were "very satisfied" with the procedure and 21.6% were "satisfied." At 15 years, 90.6% of unicompartmental arthroplasties had not been revised. Overall, the authors feel it is an excellent procedure for SONK. Price et al. reviewed 682 medial Oxford UKA knees for 20-year survival. They found the all-cause revision survival rate was 91%. 29 revision procedures occurred at a mean time of 3.3 years postoperatively. The most common cause of revision was lateral arthrosis (34%), followed closely by component loosening (31%). They concluded that Oxford medial UKA has good survival even into the second decade postoperatively. Figure A and B show AP and lateral images of a left knee status post medial unicompartmental knee arthroplasty. Specifically, this is the Oxford UKA system. Illustration A is a T2-weighted MRI demonstrating SONK. Incorrect Answers:

Correct Answer: degree varus deformity Corrent answer: 3 Inflammatory arthritides are considered contraindications for a partial knee replacement due to the likely progression of arthritis in the native compartments. Unicompartmental arthroplasty (UKA) is generally considered an excellent procedure provided that appropriate surgical indications are used for patient selection. Classic indications for UKA include unicompartmental disease in patients older than 60 with relatively low activity demands. Additionally, the patients should weigh less than 82 kg, have minimal pain at rest, have motion >90 degrees, varus deformity <10 degrees, and flexion contractures <10 degrees. While most of these classic indications are still used today, recent studies are showing excellent results in younger, heavier, and more active patients. Inflammatory arthropathy is a contra-indication to unicompartmental knee replacement due to the high risk of continued arthritis progression in the other compartments. These patients should undergo total knee replacement instead. Heyse et al. retrospectively reviewed the results of unicompartmental arthroplasty for spontaneous osteonecrosis of the knee (SONK). 75.7% of patients were "very satisfied" with the procedure and 21.6% were "satisfied." At 15 years, 90.6% of unicompartmental arthroplasties had not been revised. Overall, the authors feel it is an excellent procedure for SONK. Price et al. reviewed 682 medial Oxford UKA knees for 20-year survival. They found the all-cause revision survival rate was 91%. 29 revision procedures occurred at a mean time of 3.3 years postoperatively. The most common cause of revision was lateral arthrosis (34%), followed closely by component loosening (31%). They concluded that Oxford medial UKA has good survival even into the second decade postoperatively. Figure A and B show AP and lateral images of a left knee status post medial unicompartmental knee arthroplasty. Specifically, this is the Oxford UKA system. Illustration A is a T2-weighted MRI demonstrating SONK. Incorrect Answers:

Explanation:

unicompartmental arthroplasty. The absence of an ACL is a contraindication for mobile-bearing UKA.
OrthoCash 2020
Which of the following is the most common cause of early revision surgery (<20 weeks) following a hip resurfacing arthroplasty?
Periprosthetic fracture
Rupture of abductors
Dislocation
Heterotopic ossification
Post-operative stiffness
Periprosthetic fracture, specifically femoral neck fracture, is the most common cause of early revision less than 20 weeks following surgery.
The rate of femoral neck fractures following hip resurfacing varies, but most literature reports a rate of 1%. A majority of these fractures happen in the early post-operative period and are the most frequent cause of revision surgery within several months following surgery. The cause is usually multifactorial, but placing the femoral implant in varus, osteonecrosis, and notching have been proven risk factors for fracture.
Little el al. report on 377 patients undergoing hip resurfacing. 13 required revision including 8 for fracture of the femoral neck and 3 for loosening of a component. Evidence of osteonecrosis was seen in two of these cases, leading the authors to believe it may contributed to fracture.
Illustration A shows a comparison of a typical total hip replacement and a hip resurfacing arthroplasty. Illustration B shows notching of the femoral neck, a known cause of femoral neck fracture following hip resurfacing. Illustration C shows a femoral neck fracture in a patient with a hip resurfacing.
OrthoCash 2020
A 55-year-old male undergoes a revision total knee arthroplasty of an implant that is only 3 years old. At the time of surgery, the tibial polyethylene liner shows catastrophic delamination and cracking. What is the most likely cause of this extensive, accelerated wear of the polyethylene liner?
Sterilization in ethylene oxide
Gamma irradiation of the polyethylene liner in the presence of air
Gamma irradiation of the polyethylene liner with vacuum packaging
Gamma irradiation of the polyethylene liner in nitrogen
Gamma irradiation of the polyethylene liner in argon
Corrent answer: 2
Irradiation of polyethylene in air (i.e. oxygen present) has been shown to be a risk factor for catastrophic failure after total knee replacement.
Free radicals are generated when polyethylene is irradiated in the presence of air. Initially, these free radicals result in cross-linking. However, if the polyethylene is exposed to these free radicals for an extended period of time, delamination, cracking, and catastrophic failure may ensue. The industry has completely abandoned this method of sterilization as a result. Currently, the standard of care is irradiation of polyethylene in an inert gas (e.g. argon, nitrogen or vacuum packaging). The amount of oxidative products when polyethylene is sterilized in the absence of oxygen is much less and does not lead to catastrophic failure.
Sterilization without irradiation is another option (ethylene oxide). When this occurs, there is no cross-linking and thus the increased wear properties are lost. However, since there is no oxidization, you do not have the risk of catastrophic failure as seen in those liners irradiated in the presence of oxygen.
The cited reference by McNulty et al. from Orthopedics discusses the influence of sterilization methods on wear performance. They found that gamma irradiation and storage of the polyethylene components in an essentially oxygen-free environment imparted by gamma irradiation in a vacuum foil pouch (GVF) protects the components from oxidization.
Illustration A shows a polyethylene liner that has undergone catastrophic wear as a result of irradiation in the presence of oxygen.
Incorrect Answers:
catastrophic wear, although wear properties are less than gamma irradiation in the absence of air.
OrthoCash 2020
Which of the following interventions reduces osteolysis around distal portion of the femoral stem when performing a total hip arthroplasty?
Use of an extended offset femoral neck component
Use of a proximal circumferentially coated ingrowth stem
Use of a collared stem
Use of a long femoral stem
Ensuring that the stem fills the diaphysis of the femur
Corrent answer: 2
Osteolysis of the femur is caused by activation of macrophages by microscopic polyethylene particles within the "effective joint space", defined as any area where joint fluid can come into contact with bone. This can occur above the acetabular cup, through screw holes, and down the femoral shaft around the prosthetic stem. Ideally, with a cementless stem, both the proximal and metaphyseal femur are well filled by the prosthesis. Collared stems are used to augment poor calcar bone quality or bone loss.
Sinha et al showed in a retrospective review of 101 hips with cementless circumferentially coated femoral stems no distal femur osteolysis occurred, but 82% showed “evidence of proximal femur stress shielding”, though only 38% showed proximal femoral osteolysis.
OrthoCash 2020
During a minimally invasive approach to total hip arthroplasty a femoral periprosthetic fracture occurs. Which of the following steps is crucial to properly treat this complication?
Transitioning to an extensile approach to adequately visualize and reduce the fracture
Limiting post-operative weight bearing
Switching to a cemented femoral stem to avoid the stresses created during press-fit fixation
Delaying the arthroplasty until the fracture has healed
Supplementing the fracture with autograft
Corrent answer: 1
Proper treatment of an intraoperative femoral fracture during total hip arthroplasty involves adequate exposure, anatomic reduction, and bypassing the fracture site by 2 cortical diameters of the femur with a long stem. This may involve repositioning the patient on the table if the arthroplasty is performed in the supine position. Minimally invasive surgical techniques have been developed to insert the components through smaller exposures and less soft tissue dissection. The purported advantages include faster rehabilitation, less blood loss, shorter hospital stays, and better cosmesis. However, complications an arise if the surgeon sacrifices surgical exposure and visualization.
Fehring et al review 3 cases of total hip arthroplasty performed through minimally invasive techniques with catastrophic outcomes. Intra-operative fracture, chronic instability, and death were all identified.
OrthoCash 2020
A 70-year-old man underwent total hip arthroplasty 4 months ago and has experienced 3 dislocations. Radiographs reveal no failure of the hardware and an acetabular component that has an abduction
angle of 40 degrees and a version of 10 degrees retroverted. What is the most appropriate treatment for the recurrent dislocations?
hip abduction brace
revision of the acetabular liner to a constrained type
revision of the entire acetabular component
revision of the femoral head to a larger size
revision to an extended offset prosthesis
Corrent answer: 3
Per Dorr et al: post-operative hip instability can be caused by several factors: soft tissue imbalance, component malposition, or position. Component malposition, as in this case, should be treated with revision of the offending component. In this case the acetabulum was placed in retroversion when it should have been 15-20 degrees anteverted. None of the other options addresses the cause of the instability. According to Morrey, the most signficant risk factors to instability are prior hip surgery, trochanteric nonunion, and posterior surgical approach. He wrote that the most reliable way to correct instability is to reorient a retroverted acetabular cup.
OrthoCash 2020
In patients with sickle cell disease and asymptomatic osteonecrosis of the femoral head identified with magnetic resonance imaging, what percentage will eventually go on to femoral head collapse?

Question 86:

- A 15-year-old dancer who has had brief episodes of back pain over the past 2 years now reports a 3 month history of low back pain and a decreased tolerance for dance. Figure 22a-c show flexion and extension x-rays and CT scan. She reports no leg pain, nor any bowel or bladder difficulties. Management should now consist of

Options:

Post spinal fusion from L5to S1
Primary repair with an iliac bone graft
Post spinal fusion of L4-5
A pantaloon body cast and 6 weeks of bed rest
Rest, NSAIDS, and limited dancing

Correct Answer: Rest, NSAIDS, and limited dancing

Explanation:

Question 87:

Options:

Open reduction internal fixation (ORIF)
Sling immobilization in external rotation
Bristow-Latarjet
Shoulder hemiarthroplasty The patient has sustained a displaced lesser tuberosity fracture with medial displacement following a posterior shoulder dislocation. Nonoperative management would risk long-term loss of normal subscapularis function, as well as anterior shoulder instability. An ORIF of lesser tuberosity is recommended. The current radiographs do not demonstrate any obvious compromise of glenoid bone stock that would necessitate a coracoid transfer. The humeral head is not compromised; therefore, a hemiarthroplasty is not indicated. Correct answer : A 57 76- A 51-year-old man sustains the injury shown in the MRI scan in Figures 1 and 2 following a fall. After a thorough discussion regarding risks and benefits, he elects to proceed with surgery. What is the most appropriate surgical treatment for his fracture?
Open reduction internal fixation with locking plate
Intramedullary (IM) nail
Hemiarthroplasty
Closed reduction and percutaneous pinning The patient has sustained a complex proximal humerus fracture with head split component and multiple articular fragments. When the articular surface is significantly compromised, arthroplasty procedures are favored. The only procedure listed that addresses the damaged humeral head is hemiarthroplasty, making it the correct response. Although a possible option, ORIF would be difficult due to the fragmented humeral head, and there would be a high risk for fracture collapse or avascular necrosis. IM nailing will not provide enough control of the fracture pieces, nor will it replace the damaged articular surface. Closed reduction is not an option given the complex nature of the fracture.

Correct Answer: Bristow-Latarjet

Explanation:

Question 88:

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

Options:

3 days
1 week
10 days
2 weeks
6 weeks

Correct Answer: 2 weeks

Explanation:

DISCUSSION: 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.
REFERENCE: Tortolani JP, McAfee PC, Saiedy S: Failures of lumbar disc replacement. Sem Spine Surg 2006;18:78-86.

Question 89:

Storage of musculoskeletal allografts by cryopreservation is achieved by

Options:

replacing water in the tissue with alcohol to a moisture level of 5% and then using a vacuum process to remove the alcohol from the tissue.
maintaining maximum cellular viability of fresh tissue without long-term storage.
using chemicals to remove cellular water and controlled rate freezing to prevent ice crystal formation.
freezing the graft twice and packaging the tissue without solution at minus 80 degrees C.
freezing the graft in water without an antibiotic solution soak during quarantine, with final storage in liquid nitrogen.

Correct Answer: using chemicals to remove cellular water and controlled rate freezing to prevent ice crystal formation.

Explanation:

Question 90:

Which clinical signs are consistent with the diagnosis of cauda equina syndrome?

Options:

Saddle anesthesia, hyperreflexia, quadriceps weakness
Decreased motor function in the quadriceps and gastrocnemius, hyperreflexia,? and saddle anesthesia
More than 5 beats of clonus, saddle anesthesia, and bowel incontinence
Urinary retention, saddle anesthesia, and extensor hallucis longus weakness

Correct Answer: Urinary retention, saddle anesthesia, and extensor hallucis longus weakness

Explanation:

DISCUSSION
Cauda equina syndrome is a lower-motor neuron deficit. Hyperreflexia, clonus, and other upper-motor neuron findings would not be seen. Saddle anesthesia, motor weakness, and neurogenic bladder are elements critical to the diagnosis of cauda equina syndrome.
RECOMMENDED READINGS
Kostuik JP, Harrington I, Alexander D, Rand W, Evans D. Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am. 1986 Mar;68(3):386-91. PubMed PMID: 2936744.
View
Abstract at PubMed
Spector LR, Madigan L, Rhyne A, Darden B 2nd, Kim D. Cauda equina syndrome. J Am Acad Orthop Surg. 2008 Aug;16(8):471-9. Review. PubMed PMID: 18664636.
View Abstract at
PubMed
CLINICAL SITUATION FOR QUESTIONS 78 THROUGH 80
Figures 78a and 78b are the axial and sagittal MR images of an otherwise healthy 24-year-old woman who has had 8 weeks of severe leg pain without weakness.
A B

Question 91:

The peroneus tertius is a commonly used landmark for arthroscopic portal placement. What is the function of this tendon?

Options:

Dorsiflexion
Eversion
Dorsiflexion and eversion
Fifth toe extension
Lesser toe extension

Correct Answer: Dorsiflexion and eversion

Explanation:

DISCUSSION: The peroneus tertius, although absent in 10% of the population, originates on the distal third of the extensor surface of the fibula and inserts onto the base of the fifth metatarsal, possibly extending to the fascia over the fourth interosseous space. The muscle is located in the anterior compartment of the leg and is innervated by the deep peroneal nerve. The tendon produces dorsiflexion and eversion when walking and can be used as an insertion point during tendon transfers to assist dorsiflexion. This tendon is peculiar to humans and is a proximally migrated deep extensor of the fifth toe.
REFERENCES: Joshi SD, Joshi SS, Athavale SA: Morphology of the peroneus tertius muscle.
Clin Anat 2006;19:611-614.
Williams PL, Bannister LH, Berry MM, et al (eds): Gray’s Anatomy, ed 38. London, Churchill Livingston, 1995, p 883.
Hansen ST Jr: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott Williams & Wilkins, 2000, p 21.

Question 92:

..The optimal method to treat a recurrent presentation of pigmented villonodular synovitis (PVNS) with diffuse joint involvement in a 24-year-old woman with pain and symptomatic effusions is

Options:

700 cGy of radiation therapy.
open arthrotomy with synovectomy.
imatinib therapy.
observation. DISCUSSION.. Local control of recurrent diffuse PVNS is best accomplished with open arthrotomy and complete synovectomy. Arthroscopic methods in the setting of persistent diffuse PVNS are associated with an unacceptably high rate of recurrence. Radiation therapy (700 cGy) is the typical dose administered for heterotopic ossification prophylaxis, but this dose is not high enough to achieve local control in PVNS. Imatinib, a colony-stimulating factor inhibitor, has been described for recurrent/refractory disease, but is not considered as effective as open surgical treatment.

Correct Answer: open arthrotomy with synovectomy.

Question 93:

Histologically, synovial chondromatosis is characterized by

Options:

exuberant synovitis (Pannus).
loose fragments of articular cartilage embedded in the synovium.
ossified cartilage nodules embedded in the synovium.
the presence of granulomas in the synovium.
hemosiderin deposition in the synovium.

Correct Answer: ossified cartilage nodules embedded in the synovium.

Explanation:

Question 94:

A 14-year-old girl has had mild pain and nail deformity of the great toe for the past 4 months. A radiograph is shown in Figure 50. What is the most likely etiology of the lesion?

Options:

Fungal infection
Ingrowth of the medial nail
Benign exostosis
Malignant neoplasm
Reactive pyogenic granuloma

Correct Answer: Benign exostosis

Explanation:

Question 95:

Options:

a cortisone injection to the subscapular bursa.
posterior capsular stretching.
strengthening of the external rotators and scapular stabilizers.
continued pitching and working through the pain.
a sling and rest.

Correct Answer: posterior capsular stretching.

Explanation:

Question 96:

The mechanism for the osseous destruction is attributable to

Options:

avascular necrosis.
tumor invasion.
hypervascularity.
infection.

Correct Answer: hypervascularity.

Explanation:

DISCUSSION
This scenario is a classic example of the development of Charcot foot. A red, swollen, deformed foot without ulceration suggests neuroarthropathy. Normal inflammatory marker findings, no history of fever or chills, and radiographs demonstrating bone loss support the diagnosis. Limb elevation with dramatic reduction in erythema is also characteristic of this disease process and does not occur with infection. Total-contact casting is the cornerstone of treatment for acute Charcot disease. Hemoglobin A1C is an indicator of glucose averaged over a 3-month period, providing the most reliable indication of a patient's ongoing glucose control. The pathophysiology of bone destruction is believed to be hypervascularity of bone. Infection and Charcot disease may develop simultaneously, but the combination is rare.
RECOMMENDED READINGS
Kaynak G, Birsel O, Güven MF, Ogüt T. An overview of the Charcot foot pathophysiology. Diabet Foot Ankle. 2013 Aug 2;4. doi: 10.3402/dfa.v4i0.21117.Print 2013. PubMed PMID: 23919113.
View Abstract at PubMed
Pinzur MS, Lio T, Posner M. Treatment of Eichenholtz stage I Charcot foot arthropathy with a weightbearing total contact cast. Foot Ankle Int. 2006 May;27(5):324-9. PubMed PMID: 16701052.
View Abstract at PubMed

Question 97:

Which of the following is an advantage of using blocking screws for tibial nailing?

Options:

Decrease risk of nail breakage
Eliminate use of interlocking screws
Allow for larger nail use
Enhance construct stiffness
Decrease torsional rigidity

Correct Answer: Decrease risk of nail breakage

Explanation:

Question 98:

Options:

Excessive anteversion of the humeral component
Excessive anteversion of the glenoid component
Excessive posterior capsular laxity
Anterior capsular laxity
Use of an oversized humeral head

Correct Answer: Excessive posterior capsular laxity

Explanation:

Question 99:

Which of the following ligaments is the primary static restraint against inferior translation of the arm when the shoulder is in 0 degrees of abduction?

Options:

Middle glenohumeral
Inferior glenohumeral
Coracoacromial
Coracoclavicular
Coracohumeral

Correct Answer: Coracohumeral

Explanation:

Question 100:

Options:

ice, analgesics, and symptomatic treatment, with delayed reconstruction if necessary.
closed reduction in the emergency department.
closed reduction in the operating room under anesthesia.
open reduction and temporary stabilization with a threaded pin.
open reduction and reconstruction of the sternoclavicular joint ligaments.

Correct Answer: closed reduction in the operating room under anesthesia.

Explanation:

DISCUSSION: The CT scan reveals a completely displaced physeal fracture of the medial clavicle with marked posterior displacement of the distal fragment. This fracture pattern is associated with potential injury to the vascular structures of the mediastinum. Reduction should be performed for this fracture and generally can be done closed with shoulder retraction and upward pull on the clavicle with a towel clip. Once reduced, the fracture is relatively stable and typically will heal in good position. Reduction should be performed in the operating room in the event that a vascular injury is detected once compression is removed from the clavicle. Open reduction may be necessary if closed reduction is not possible; however, pinning or ligament reconstruction usually is not necessary.
REFERENCES: Rockwood CA, Matsen FA (eds): The Shoulder, ed 2. Philadelphia, PA,
WB Saunders, 1998, p 581.
Wirth MA, Rockwood CA Jr: Acute and chronic traumatic injuries of the sternoclavicular joint. J Am Acad Orthop Surg 1996;4:268-278.

OITE & ABOS Orthopedic Exam MCQs: Trauma, Foot & Knee Board Review Part 132

OITE & ABOS Orthopedic Board Prep MCQs: Trauma & Nerve Injuries Part 96

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 96

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index