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

Orthopedic Board Prep MCQs: Elbow, Fracture & Nerve | OITE & ABOS Part 218

27 Apr 2026 251 min read 54 Views
OITE & ABOS Orthopedic Board Prep: Practice Exam Part 218

Key Takeaway

This page offers a professional medical board review quiz, Part 218, for orthopedic surgeons preparing for AAOS and ABOS board certification exams. It contains 100 high-yield, verified MCQs in OITE/AAOS format, focusing on Elbow, Fracture, and Nerve topics. Designed to simulate the real exam for optimal preparation.

About This Board Review Set

This is Part 218 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.

How to Use the Interactive Quiz

Two distinct learning modes are available:

  • Study Mode — After selecting an answer, you immediately see whether you are correct or incorrect, together with a full clinical explanation and literature references.
  • Exam Mode — All feedback is hidden until you click Submit & See Results. A live timer tracks elapsed time. A percentage score and detailed breakdown are displayed upon submission.

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 218

This module focuses heavily on: Elbow, Fracture, Nerve.

Sample Questions from This Set

Sample Question 1: A 72-year-old female presents to the office 5 weeks after distal radius fracture surgery with the findings seen in Figure A. She performed daily cleansingwith soap and water and dry dressings. Which of the following has been shown to decrea...

Sample Question 2: An acute posterolateral disk herniation at the L4-5 level will most likely affect what nerve root? Review Topic...

Sample Question 3: Failure of high tibial osteotomy (HTO) is most closely associated with which of the following factors?...

Sample Question 4: Closed chain kinetic exercises are differentiated from open chain exercises by which of the following? Review Topic...

Sample Question 5: View Abstract at PubMedFigures 87a and 87b are sagittal and coronal MR images of the affected elbow of a 36-year-old man who has a history of painful mechanical symptoms in his dominant arm when extending his elbow in full supination. What ...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam


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Question 1

A 72-year-old female presents to the office 5 weeks after distal radius fracture surgery with the findings seen in Figure A. She performed daily cleansing with soap and water and dry dressings. Which of the following has been shown to decrease the risk of developing this complication?





Explanation

There is no difference between daily showers with soap, water and dry dressings, and solutions comprising (1) saline and chlorhexidine, or (2) saline and hydrogen peroxide.
The risks of external fixation include cellulitis, pin-track drainage, osteomyelitis and pin loosening. The rate of complications is about 20%. Chlorhexidine gluconate has broad spectrum activity against gram-positive and negative bacteria by disrupting cell membranes. It is not affected by blood and has low skin irritancy. Studies show that simple pin-site care (showers, dry dressings) maintains a low infection rate.
Egol et al. performed a randomized trial examining external fixation pin tracts about the wrist. They compared (1) weekly dry dressings, (2) daily pin care with half normal saline (NS) and hydrogen peroxide (H2O2) and (3) chlorhexidine discs with weekly changes. They found pin-site complications in 19%, with no difference between the 3 groups. They do not recommend additional wound care beyond sterile dressings.
Stinner et al. performed a survey on the use of half-pins by the limb lengthening and reconstruction society. They found that most respondents preferred hydroxyapatite coating (81%) because of improved fixation and decreased loosening (less radiographic pin-tract rarefaction and greater extraction torque, which may lead to
lower infection rates). Most encouraged shower (60%) and washing solution (67%)(soap and water, peroxide or saline) for pin site care.
Figure A shows an external fixator around the wrist with cellulitis around the proximal half-pins.
Incorrect Answers

Question 2

An acute posterolateral disk herniation at the L4-5 level will most likely affect what nerve root? Review Topic





Explanation

Posterolateral disk herniations will generally compress the transversing nerve root. Therefore, a posterolateral disk herniation at the L4-5 level will typically compromise the L5 nerve root. Far lateral (extraforaminal) disk herniations generally compromise the exiting nerve root. Therefore, an extraforaminal herniation at the L4-5 level will typically compromise the exiting L4 nerve root.

Question 3

Failure of high tibial osteotomy (HTO) is most closely associated with which of the following factors?





Explanation

DISCUSSION: Long-term survivorship studies have attempted to clarify patient factors related to good outcomes in HTO.  One particular study showed that a patient age of less than 50 years was related to good outcomes in those who had good preoperative knee flexion.  The same study found no relation between HTO failure and the presence of postoperative infection or deep venous thrombosis.  The presence of a lateral tibial thrust is a contraindication to performing this surgery.  As expected, good patient selection is critical to obtaining good long-term results

with HTO.

REFERENCES: Naudie D, Borne RB, Rorabeck CH, Bourne TJ: Survivorship of the high tibial valgus osteotomy: A 10- to 22-year followup study. Clin Orthop 1999;367:18-27.
Rinonapoli E, Mancini GB, Corvaglia A, Musiello S: Tibial osteotomy for varus gonarthrosis: A 10- to 21-year followup study. Clin Orthop 1998;353:185-193.
Coventry MB, Ilstrup DM, Wallrichs SL: Proximal tibial osteotomy: A critical long-term study of eighty-seven cases. J Bone Joint Surg Am 1993;75:196-201.

Question 4

Closed chain kinetic exercises are differentiated from open chain exercises by which of the following? Review Topic





Explanation

Closed chain kinetic exercises confer a margin of safety and are protective of healing or repaired tissues by the compressive nature of the applied forces. Closed chain kinetic exercise is associated with decreased shear, translation, and distraction of the joints within the chain. Because of patterns of motion with closed chain kinetic exercises, individual muscles may not be maximally strengthened or all joint motion returned to normal. Closed chain kinetic exercises may be used earlier in the rehabilitation process.

Question 5

View Abstract at PubMed Figures 87a and 87b are sagittal and coronal MR images of the affected elbow of a 36-year-old man who has a history of painful mechanical symptoms in his dominant arm when extending his elbow in full supination. What is the most likely cause of his painful snapping? A B




Explanation

DISCUSSION
The MRI studies show a radiocapitellar plica. This anomalous structure has been associated with symptomatic snapping. Lacertus fibrosis contracture will not cause painful snapping. An intra-articular pathology such as loose bodies is not present on these imaging studies. Olecranon fossa impingement causes posterior pain in extension and is not shown in the images.
RECOMMENDED READINGS
Antuna SA, O'Driscoll SW. Snapping plicae associated with radiocapitellar chondromalacia. Arthroscopy. 2001 May;17(5):491-5. PubMed 11337715. View Abstract at PubMed
Ruch DS, Papadonikolakis A, Campolattaro RM. The posterolateral plica: a cause of refractory lateral elbow pain. J Shoulder Elbow Surg. 2006 May-Jun;15(3):367-70. PubMed PMID: 16679240. View Abstract at PubMed

Question 6

A 21-year-old man has mild but persistent aching pain in his left proximal thigh during impact loading activities. He denies pain at rest and has no other symptoms. Figures 34a through 34e show the radiographs and T1-weighted, T2-weighted, and gadolinium MRI scans of the left hip. What is the most likely diagnosis?





Explanation

DISCUSSION: The radiographs show a centrally located radiolucent lesion with cortical thinning and mild osseous expansion; these findings are the hallmarks of a simple bone cyst.  Whereas this particular lesion does not demonstrate sclerosis, the distinct margin of this lesion with sharp transition to normal bone is common.  The MRI scans reveal a purely cystic lesion with bright T2 signal, and the gadolinium image shows the classic rim enhancement of cystic lesions.  Fibrous dysplasia with cystic degeneration might have a very similar appearance and should be considered in the differential diagnosis.
REFERENCES: Parsons TW: Benign bone tumors, in Fitzgerald RH, Kaufer H, Malkani AL (eds): Orthopaedics.  St Louis, MO, Mosby, 2002, pp 1027-1035.
May DA, Good RB, Smith DK, et al: MR imaging of musculoskeletal tumors and tumor mimickers with intravenous gadolinium: Experience with 242 patients.  Skeletal Radiol 1997;26:2-15.
Resnick D, Kyriakos M, Greenway GD: Tumors and tumor-like lesions of bone: Imaging and pathology of specific lesions, in Resnick D (ed): Diagnosis of Bone and Joint Disorders, ed 4.  Philadelphia, PA, WB Saunders, 2002, vol 4, pp 4023-4034.

Question 7

This condition is most prevalent in people of which ancestry?




Explanation

DISCUSSION
The radiograph of the lateral lumbosacral spine reveals an isthmic spondylolysis with a Meyerding grade 1 spondylolisthesis. The incidence of spondylolysis in the general population is around 5%, and grade 1 or 2 slips are present in the majority of children with a spondylolysis. Many cases of spondylolysis are painless and discovered incidentally, but, when painful, hyperextension of the lumbar spine may stress the area of the pars defect and exacerbate a patient’s symptoms. A diagnosis can usually be determined with a lateral radiograph of the lumbar spine. Although oblique lumbar radiographs are frequently ordered, several studies have shown that they do not increase diagnostic or prognostic accuracy. Progression of an isthmic spondylolysis, with or without a grade 1 or 2 listhesis, to a serious slip that might
necessitate surgical intervention is rare and occurs in fewer than 5% of patients. Chance for progression diminishes with age, with patients at highest risk prior to the adolescent growth spurt. Spondylolysis may have a genetic component; an increased prevalence has been found in some families and in some ethnic groups, especially among the Native American population.

Question 8

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 9

Figure 242 is the anteroposterior radiograph of a 28-year-old man who underwent resection and reconstruction for an Ewing sarcoma. What is the most common functional deficit encountered during rehabilitation?





Explanation

Question 10

Ewing’s sarcoma of bone most commonly occurs in which of the following locations?





Explanation

DISCUSSION: Ewing’s sarcoma typically occurs in the major long tubular bones, with the femur the most common location.  The flat bones of the pelvis are the second most common location.  Ewing’s sarcoma occurs in the fibula but with a lower incidence than that seen in the major tubular bones.  Ewing’s sarcoma infrequently occurs in the metacarpals or the vertebral bodies.
REFERENCES: Simon M, Springfield D, et al: Ewing’s Sarcoma: Surgery for Bone and Soft Tissue Tumors.  Philadelphia, PA, Lippincott Raven, 1998, p 287.
Wold LA, et al: Ewing’s Sarcoma: Atlas of Orthopaedic Pathology.  Philadelphia, PA, WB Saunders, 1990, pp 210-211.

Question 11

Figures 1 through 3 demonstrate the radiographs obtained from a 45-year-old construction worker who has wrist pain, loss of motion, and loss of strength. Nonsurgical measures have failed, and the patient requests surgery. What is the best surgical option for this patient?




Explanation

EXPLANATION:
This patient has a physically demanding occupation. His radiographs show a long-standing nonunion with avascular necrosis and collapse of the proximal pole. This condition is referred to as a scaphoid nonunion advanced collapse wrist (SNAC). He has advanced arthritis of the capitolunate joint, but the radiolunate joint is preserved. The best option for him would be scaphoid excision with four-corner fusion. Proximal row carpectomy, would be incorrect because of the advanced arthritis of the capitolunate joint. This procedure relies on normal cartilage/joint articulation of the capitate as well as of the lunate fossa of the distal radius. Proximal pole scaphoid excision alone would not address the advanced arthritis of the capitolunate joint. Scaphoid fixation with bone grafting would not address the midcarpal arthritis and advanced proximal pole collapse.

Question 12

The use of knee arthroscopy following total knee arthroplasty is most effective in treating which of the following conditions?





Explanation

DISCUSSION: Patellar clunk syndrome is associated with certain types of posterior stabilized knee arthroplasties.  Arthroscopic resection of the band of inflammatory tissue inferior to the patellar component is effective in treating this condition.  Arthroscopic lavage of infected knee arthroplasties is not associated with an acceptable success rate.  Diagnostic arthroscopy for nonspecific pain following arthroplasty is not uniformly successful.  Patellar component maltracking is frequently associated with component malposition and is not alleviated by an arthroscopic lateral release.  Synovitis secondary to polyethylene wear is best treated by exchange of the polyethylene spacer and not arthroscopic synovectomy.
REFERENCES: Lucas TS, DeLuca PF, Nazarian DG, et al: Arthroscopic treatment of patellar clunk.  Clin Orthop 1999;367:226-229.
Takahashi M, Miyamoto S, Nagano A: Arthroscopic treatment of soft-tissue impingement under the patella after total knee arthroplasty.  Arthroscopy 2002;18:E20.

Question 13

What is the heaviest weight that can be safely applied to the adult cervical spine via Gardner-Wells tong traction?





Explanation

DISCUSSION: Cotler and associates reported on the use of awake skeletal traction to reduce facet fracture-dislocations in 24 patients.  Seventeen patients required more than 50 pounds of traction (the “traditional” limit) to achieve reduction.  More than 100 pounds of traction was safely used in one-third of the patients in this study.  A cadaver study has supported the safe use of traction with weights in excess of 100 pounds. 
REFERENCES: Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocation using traction weights up to 140 pounds.  Spine 1993;18:386-390.
Anderson DG, Vacccaro AR, Gavin K: Cervical orthoses and cranioskeletal traction, in Clark CR (ed): The Cervical Spine, ed 4.  Philadelphia, PA, Lippincott Williams & Wilkins, 2005,

pp 110-121.

Question 14

What pharmacologic agents are preferred for the treatment of symptomatic active Paget’s disease?





Explanation

DISCUSSION: Recent medical literature supports the use of bisphosphonates as the treatment of choice for active Paget’s disease.
REFERENCE: Delman PD, Meunier PJ: The management of Paget’s disease.  N Eng J Med 1997;336:558-566.

Question 15

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





Explanation

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

Question 16

A 46-year-old man reports occasional squeaking of his hip 2 years after undergoing an uneventful total hip arthroplasty. History reveals no pain, physical examination cannot reproduce audible squeaking, and radiographs show appropriate implant position. What is the most appropriate management?





Explanation

DISCUSSION: In the absence of component malpositioning, hip pain, or other compelling reasons to reoperate, a squeaking ceramic bearing is not an indication for revision surgery. The patient can be reassured and observed.
Hopefully, with a better understanding of acoustic phenomena following ceramic total hip arthroplasty, this complication can be minimized.
REFERENCES: Yang CC, Kim RH, Dennis DA: The squeaking hip: A cause for concem-disagrees. Orthopedics
2007;30:739-742.
Walter WL, O’Toole GC, Walter WK, et al: Squeaking in ceramic-on-ceramic hips: The importance of acetabular component orientation. J Arthroplasty 2007;22:496-503.

Figure 80a Figure 80b

Question 17

A year-old man with a history of Legg-Calve-Perthes disease underwent a right hip resurfacing 3 years ago with no perioperative complications. Hip pain has developed gradually during the last 4 months. Radiographs show no evidence of fixation loosening or any adverse changes at the femoral neck. No periarticular osteolysis is evident. A large intra-articular and intrapelvic pseudotumor has developed. What predominant histological feature(s) is/are present in such a lesion?




Explanation

DISCUSSION:
Controversy persists over what exactly is the best approach to managing patients with metal-on-metal (MOM)  hip  arthroplasties.  All  patients  with  painful  MOM  hip  arthroplasties  should  be  examined  for fixation  loosening,  wear/osteolysis,  and  infection—no  differently  than  patients  without  MOM  hip arthroplasties.  It  is  recommended  to  obtain  serum  trace  element  levels.  If  the  levels  are  high,  cross- sectional imaging should be obtained to determine whether any pseudotumor or tissue necrosis is present around the hip arthroplasty. Hip aspiration should be considered if concern for infection exists. Adverse tissue reaction has been identified to occur around MOM hip arthroplasties. The predominant histologic
feature is tissue necrosis with infiltration of lymphocytes and plasma cells.

Question 18

A 28-year-old professional dancer reports a 3-month history of progressive pain in the posterior aspect of the left ankle. Her symptoms are worse when she assumes the en pointe position. Examination reveals tenderness to palpation at the posterolateral aspect of the ankle posterior to the peroneal tendons which is made worse with passive plantar flexion. There is no nodularity, fluctuance, or tenderness of the Achilles tendon. The neurovascular examination is unremarkable. A lateral radiograph and MRI scan are shown in Figures 16a and 16b, respectively. Management should consist of





Explanation

DISCUSSION: The imaging studies reveal findings typical of the os trigonum syndrome.  This condition results from inflammation between the os trigonum and the adjacent talus.  The symptoms of posterior ankle pain are exacerbated by plantar flexion, which stresses the fibrous union between these two bones.  Definitive management of the high-level athlete involves excision of the os trigonum from a medial approach, although arthroscopic excision has also been described.  The os trigonum is not an intra-articular structure; therefore, ankle arthroscopy is neither diagnostic nor therapeutic.
REFERENCES: Abramowitz Y, Wollstein R, Barzilay Y, et al: Outcome of resection of a symptomatic os trigonum.  J Bone Joint Surg Am 2003;85:1051-1057.
Mouhsine E, Crevoisier X, Leyvraz P, et al: Post-traumatic overload or acute syndrome of the os trigonum: A possible cause of posterior ankle impingement.  Knee Surg Sports Traumatol Arthrosc 2004;12:250-253.
Wredmark T, Carlstedt CA, Bauer H, et al: Os trigonum syndrome: A clinical entity in ballet dancers.  Foot Ankle 1991;11:404-406.

Question 19

Which of the following represents the most appropriate treatment at this time?





Explanation

DISCUSSION FOR QUESTIONS 104 THROUGH 106:
This is a classic presentation of a giant cell tumor. It is a benign aggressive bone tumor consisting of distinct undifferentiated mononuclear cells. Most occur in patients 30 years to 50 years of age (90% are older than age 20 years) and affect woman more than men. Pain and swelling for 2 to 3 months is classic.The most common location is the distal femur. The biopsy specimen shows multinucleated giant cells amid a background of mononuclear cells. This benign tumor may rarely metastasize to the lung (less than 2% of the time). A CT scan of the chest is required to rule out any further lesions. Curettage, with local adjuvants, such as phenol, cryotherapy, or argon beam, and cementation represents the best treatment option at this time.
CLINICAL SITUATION FOR QUESTIONS 107 THROUGH 109
An otherwise healthy 65-year-old man reports progressive and unrelenting back pain for the last 6 weeks that is nonmechanical in nature. He denies leg pain, weakness, bowel or bladder symptoms, and any significant past medical history. His pain is increased at night. Examination reveals pain with percussion throughout his thoracic spine. He is neurologically intact. AP and lateral radiographs of the thoracic and lumbar areas show diffuse osteopenia with no fractures.

Question 20

An 8-year-old girl injures her elbow playing soccer. After attempted reduction in the emergency department, radiographs of the elbow are shown in Figures 35a through 35c. What is the next most appropriate step in treatment?





Explanation

DISCUSSION: Ninety percent of injuries to the proximal radius in children are radial neck fractures, and 50% of these fractures are through the metaphyseal bone.  The remaining 50% are Salter-Harris type I or II fractures.  These radiographs show a fracture of the radial head and subluxation of the radius anteriorly.  Most congenital radial head dislocations are posterior lateral.  Nonsurgical treatment modalities are unlikely to be successful due to the wide displacement of the fracture fragments, as well as dislocation of the radial head.
REFERENCES: Leung AG, Peterson HA: Fractures of the proximal radial head and neck in children with emphasis on those that involve the articular cartilage.  J Pediatr Orthop

2000;20:7-14.

Hashemi-Nejad A, Goddard NJ: Radial head fractures.  Br J Hosp Med 1994;51:223-226.
Rodriguez Merchan EC: Displaced fractures of the head and neck of the radius in children: Open reduction and temporary transarticular internal fixation.  Orthopedics 1991;14:697-700.

Question 21

An axillary nerve lesion may cause weakness in the deltoid and the





Explanation

DISCUSSION: While the most prominent functional deficit from axillary nerve lesions occurs from denervation of the deltoid, denervation of the teres minor also occurs.
REFERENCE: Hollinshead WH: Anatomy for Surgeons: The Back and Limbs.  New York, NY, Harper & Row, 1969.

Question 22

Figure 1 is the MRI scan of a 19-year-old man who has an acute anterior shoulder dislocation. The bony fragment occupies 10% of the glenoid articular surface. What is the most appropriate treatment? Review Topic




Explanation

The MRI scan shows a bony Bankart lesion involving less than 20% of the glenoid joint surface. A recent series reported high success rates after arthroscopic treatment when the defect is incorporated into the repair. Anterior bony deficiencies occupying more than 25% to 30% of the glenoid joint surface treated with soft-tissue repair only are associated with high recurrence rates. In these patients, an open or arthroscopic coracoid transfer or structural iliac crest graft should be considered. Open reduction and internal fixation has been reported for treatment of large acute glenoid rim fractures but is not recommended for recurrent anterior shoulder instability in the setting of a 10% glenoid rim fracture.

Question 23

A professional baseball player has had intermittent, mild shoulder pain for the past 2 years. Nonsurgical management has consisted of anti-inflammatory drugs. Examination reveals atrophy of the infraspinatus muscle but not the supraspinatus. There is weakness in external rotation with the arm at his side but not at 90 degrees of abduction. He has no weakness or pain with resisted abduction. Electromyography confirms an isolated lesion of the suprascapular nerve branch to the infraspinatus. He is otherwise neurologically intact. An MRI scan of the shoulder shows no cysts but confirms atrophy of the infraspinatus muscle. What is the next most appropriate step in management?





Explanation

DISCUSSION: Suprascapular nerve injuries are more commonly seen in athletes who participate in overhead activities.  When a patient is evaluated for posterior shoulder pain and infraspinatus muscle weakness or atrophy, electrodiagnostic studies are an essential part of the evaluation.  In addition, imaging studies are indicated to exclude other diagnoses that can mimic a suprascapular nerve injury.  Initial management should consist of cessation of the aggravating activity along with an organized shoulder rehabilitation program.  If nonsurgical management fails to provide relief within 6 months to 1 year, surgical exploration of the suprascapular nerve should be considered.  Release of the spinoglenoid ligament with resultant suprascapular nerve decompression may result in pain relief and a return of normal shoulder function.  In this patient, who has a chronic neuropathy and mild symptoms, surgery is indicated only if nonsurgical management fails to provide relief and he is unable to perform at his position.
REFERENCES: Cummins CA, Bowen M, Anderson K, et al: Suprascapular nerve entrapment at the spinoglenoid notch in a professional baseball pitcher.  Am J Sports Med 1999;27:810-812.
Cummins CA, Messer TM, Nuber GW: Suprascapular nerve entrapment.  J Bone Joint Surg Am 2000;82:415-424.
Ferretti A, De Carli A, Fontana M: Injury of the suprascapular nerve at the spinoglenoid notch: The natural history of infraspinatus atrophy in volleyball players.  Am J Sports Med 1998;26:759-763.

Question 24

Figure below depicts the radiograph obtained from a 52-year-old woman who has leg-length inequality and chronic, activity-related buttock discomfort. This problem has been lifelong, but it is getting worse and increasingly causing back pain. What is the best current technique for total hip arthroplasty?




Explanation

DISCUSSION:
A high hip center is not recommended for Crowe type IV hips because of the lack of acetabular bone and altered hip biomechanics. An anatomic center is a better option but necessitates a technique to address the tight  soft-tissue  envelope.  A  trochanteric  osteotomy  with  progressive  femoral  shortening  has  been described but can be prone to trochanter nonunion. Iliofemoral lengthening prior to surgery has been described  but  may  not  be  tolerated  by  all  patients.  A  shortening  subtrochanteric  osteotomy  avoids trochanter nonunion and allows adjustment of femoral anteversion. Fixation of the osteotomy can include a stem with distal rotational control, plate fixation, a step versus oblique cut, or strut grafts.

Question 25

A 25-year-old tennis player has shoulder pain and weakness to external rotation. MRI scans are shown in Figures 16a and 16b. What is the most likely cause of his weakness?





Explanation

DISCUSSION: The MRI scans show a paralabral cyst, which is most commonly associated with labral tears.  Compression of the suprascapular nerve results in weakness of the supraspinatus and/or infraspinatus depending on the level of compression. 
REFERENCES: Piatt BE, Hawkins RJ, Fritz RC, et al: Clinical evaluation and treatment of spinoglenoid notch ganglion cysts.  J Shoulder Elbow Surg 2002;11:600-604.
Inokuchi W, Ogawa K, Horiuchi Y: Magnetic resonance imaging of suprascapular nerve palsy. 

J Shoulder Elbow Surg 1998;7;223-227. 

Question 26

A 40-year-old man is thrown off his motorcycle and sustains an open Type IIIA fracture shown in Figure A. He is taken to the operating room for debridement and reamed intramedullary nailing with a 10mm diameter nail. He returns at 10 months with persistent pain at the fracture site with ambulation. Examination reveals healed wounds with no erythema, warmth or tenderness. Erythrocyte sedimentation rate and C-reactive protein levels are within normal limits. Radiographs taken at that time are shown in Figure B. What is the next best treatment step?





Explanation

This man had a mid-diaphyseal tibial fracture that has gone into nonunion. Reamed exchange nailing is indicated.
Tibial delayed union can be defined as lack of union from 20-26 weeks post-injury, while nonunion is defined as lack of healing at >9mths post-injury, or absence of progressive signs of healing on radiographs for 3 consecutive months. Persistent pain is a symptom of nonunion. ESR and CRP are performed to rule out infection.
Bhandari et al. performed a blinded, multicenter trial on 622 reamed tibial nails and 604 unreamed tibial nails. In closed fractures, patients in the unreamed nail group were at greater risk of primary events than the reamed nail group. There was no difference in groups for open fractures. Primary events were defined as bone-grafting, implant exchange/removal, dynamization, and debridement.
Hak reviewed aseptic tibial nonunion. They discuss exchanged reamed nailing for diaphyseal nonunion, adjunctive plate fixation for metaphyseal nonunion, and nail removal and plating for metadiaphyseal nonunion, external fixation for infected nonunion and distraction osteogenesis of defects.
Figure A shows a mid-diaphyseal tibial fracture Figure B shows nonunion following
IM nailing of the fracture. Illustration A shows union following exchange nailing with a larger 12mm diameter nail.
Incorrect Answers:

Question 27

A 30-year-old farmer undergoes replantation of an above-the-elbow amputation. What form of management is most important following this surgery?





Explanation

DISCUSSION: After major limb replantation, the occurrence of ischemic rhabdomyonecrosis can result in lactic acidosis and myoglobulinemia.  These complications can be limited by rapid repair of the arterial supply, potentially using a shunt before skeletal stability.  Repair of the venous system should be performed after repair of the artery.  High volume fluid replacement will maintain a diuresis, thus limiting the complications from myoglobulinemia.
REFERENCES: Wood MB: Replantations about the elbow, in Morrey BF (ed): The Elbow and Its Disorders.  Philadelphia, PA, WB Saunders, 1985, pp 472-480.
Goldner RD, Nunley JA: Replantation proximal to the wrist, in Wood MD (ed) Hand Clinics: Microsurgery.  Philadelphia, PA, WB Saunders, 1992, pp 413-425.

Question 28

A 75-year-old woman who sustained a fall now reports neck pain and upper extremity weakness. Examination reveals 4 of 5 strength in the upper extremities and 5 of 5 strength in the lower extremities. Radiographs show multilevel degenerative disk disease. An MRI scan is shown in Figure 96. Her clinical presentation is most compatible with which of the following? Review Topic





Explanation

The MRI scan shows advanced multilevel degenerative changes and moderate to severe stenosis at C3-C4 and C4-C5 with associated cord signal change. The patient has greater weakness in the upper extremities than in the lower extremities. This pattern is most compatible with central cord syndrome. Patients with brachial plexus injury will have unilateral weakness. Patients with anterior cord syndrome will have greater weakness in the legs than in the arms, and those with Brown-Séquard syndrome will have ipsilateral motor deficits and contralateral pain and temperature deficits.

Question 29

Figures 1 and 2 are the most recent radiographs of an 18-year-old high school student who sustains an anterior shoulder dislocation playing recreational football. He has a low Beighton score on physical examination. He was closed reduced and underwent a course of physical therapy but had a second dislocation playing recreational basketball. What is the most appropriate course of treatment, with the lowest complication rate, to prevent further dislocation?




Explanation

The patient has recurrent instability and is at a high rate of further dislocations due to his young age. Therefore, therapy and bracing are unlikely to decrease his dislocation rate. The radiographs are normal, and there is no Hill-Sachs lesion or bony Bankart lesion. His instability severity index score is 3, and; therefore, a bony procedure such as Latarjet is not necessary. Furthermore, the rate of complication following a Latarjet procedure, especially nerve
injury and hardware problems, exceeds that of arthroscopic Bankart repair.              

Question 30

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





Explanation

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

Question 31

In  total  knee  arthroplasty,  in  vitro  testing  has  shown  that  cross-linking  can  diminish  the  rate  of polyethylene  wear  by  30%  to  80%.  What  other  change  in  material  properties  is  possible  when polyethylene is highly cross-linked?




Explanation

DISCUSSION:
The most important concern regarding highly cross-linked polyethylene relates to decreased mechanical properties.  Cross-linking  results  in  reduced  ductility,  tensile  strength,  and  fatigue  crack  propagation resistance. These problems have not been shown to cause implant failure in the most recent clinical trials, but  they  remain  the  most  important  mechanical  issues  associated  with  current  material  processing methods.

Question 32

A 20-year-old basketball player sustains a knee injury during a game and is seen in the orthopaedic clinic 3 days after injury. Examination reveals a positive Lachman, pivot shift, joint line tenderness, and moderate effusion. Which of the following tissue injuries is most likely causing the jointline tenderness?





Explanation

DISCUSSION: The physical examination findings are consistent with an acute anterior cruciate ligament tear. In the acute setting, a lateral meniscus tear is a more common secondary injury than a medial meniscus tear. In one study of acute anterior cruciate ligament tears in alpine skiers, the incidence of lateral meniscus tears was over four times that of medial meniscus tears. Medial meniscus tears are more common in the chronic setting, most likely secondary to its role as a secondary restraint.
REFERENCES: Garrick JG (ed): Orthopaedic Knowledge Update: Sports Medicine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, p 201.
Greis PE, Bardana DD, Holmstrom MC, et al: Meniscal injury: I. Basic science and evaluation. J Am Acad Orthop Surg 2002;10:168-176.
Duncan JB, Hunter R, Purnell M, et al: Meniscal injuries associated with acute anterior cruciate ligament tears in alpine skiers. Am J Sports Med 1995;23:170-172.

Question 33

With respect to the structure identified by the arrow in Figure 22b, the meniscofemoral 25 ligaments are




Explanation

DISCUSSION
The stress radiographs demonstrate posterior instability of the right knee in flexion. The MR images demonstrate injury to both the anterior and posterior cruciate ligament (PCL), with the stump identified with the arrow on the MR image (Figure 22b). The PCL has 2 functional bands. The anterolateral bundle originates from the roof of the intercondylar notch. It runs in a posterolateral direction onto the tibial crest between the posterior attachment of the medial and lateral menisci. During a double-bundled posterior ligament reconstruction, the
anterolateral bundle is tensioned with the knee in a position of mid flexion. The posteromedial bundle has a variable pattern of tension both in extension and in high flexion. Tensioning of the posteromedial bundle in extension may contribute to resistance against knee hyperextension.
The meniscofemoral ligaments are variably present. Although 93% of knees have been reported to have at least 1 meniscofemoral ligament present, both ligaments are simultaneously present in approximately 50% of knees. The ligament of Humphrey (anterior meniscofemoral ligament) and ligament of Wrisberg (posterior meniscofemoral ligament) are delineated by their anatomic relationship to the posterior cruciate.
RECOMMENDED READINGS
Amis AA, Bull AM, Gupte CM, Hijazi I, Race A, Robinson JR. Biomechanics of the PCL and related structures: posterolateral, posteromedial and meniscofemoral ligaments. Knee Surg Sports Traumatol Arthrosc. 2003 Sep;11(5):271-81. Epub 2003 Sep 5. Review. PubMed PMID: 12961064.View Abstract at PubMed
Amis AA, Gupte CM, Bull AM, Edwards A. Anatomy of the posterior cruciate ligament and the meniscofemoral ligaments. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):257-63. Epub 2005 Oct 14. Review. PubMed PMID: 16228178.
View Abstract at PubMed 26

Question 34

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





Explanation

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

Question 35

Figure 16 shows the radiograph of an otherwise healthy 62-year-old woman who fell. Management should consist of





Explanation

DISCUSSION: The radiograph reveals that the femoral component is grossly loose as evidenced by disruption of the cement column; therefore, retention of the original components will not yield a successful outcome.  A cementless revision is the procedure of choice.  A strut graft and/or plate may be added at the surgeon’s discretion.  A resection arthroplasty would only be considered in a nonambulatory patient.  Cemented fixation of the revision component would be problematic given the numerous fracture fragments and the inability to contain the cement. 
REFERENCES: Springer BD, Berry DJ, Lewallen DG: Treatment of periprosthetic fractures following total hip arthroplasty with femoral component revision.  J Bone Joint Surg Am 2003;85:2156-2162.
Duwelius PJ, Schmidt AH, Kyle RF, et al: A prospective, modernized treatment protocol for periprosthetic femur fractures.  Orthop Clin North Am 2004;35:485-492.

Question 36

below shows the abdominal radiograph obtained from a year-old woman who experiences nausea and abdominal tightness 48 hours following left total knee arthroplasty performed under general anesthesia. She received 24 hours of cefazolin antibiotic prophylaxis and a patient-controlled analgesia narcotic pump for pain management. She has been receiving warfarin for thromboembolic prophylaxis. Her severe abdominal distension and markedly decreased bowel sounds are most likely secondary to the administration of




Explanation

DISCUSSION:
The  radiograph  reveals  severe  intestinal  dilatation,  which  has  occurred  as  the  result  of  acute  colonic pseudo-obstruction  and  is  associated  with  excessive  narcotic  administration  following  total  joint arthroplasty. Anesthetic type, antibiotic administration, and warfarin have not been associated with this obstruction. Electrolyte imbalances such as hypokalemia have been associated with postsurgical acute colonic pseudo-obstruction.

Question 37

A 36-year-old man was injured in a motorcycle collision and sustained the injury shown in Figure 70. He has a blood pressure (BP) of 70/40 mm Hg, pulse of 148 beats per minute (bpm), and Glasgow Coma Scale score of 6 (scores lower than 8 indicate severe brain injury), and there is negligible urine output. His airway is secure and intravenous (IV) access is obtained. Two liters of warm crystalloid solution are given; repeated vital signs reveal the same BP and a pulse of 142 bpm. What is the best next step?




Explanation

DISCUSSION
This patient has an anteroposterior compression pelvic fracture associated with shock. In patients with closed pelvic fractures and hypotension, mortality rises to approximately 1 in 4 (10%-42%) and hemorrhage is the major reversible contributing factor. Initial management of a major pelvic disruption associated with hemorrhage requires hemorrhage control and rapid fluid resuscitation. A pelvic binder should be placed to reduce pelvic volume. The patient has signs and symptoms of class IV hemorrhage, which include marked tachycardia exceeding 140, a significant decrease in BP, and a very narrow pulse pressure. Urinary output is negligible, and mental status is markedly depressed. The skin is cold and pale. The degree of exsanguination with class IV hemorrhage is immediately life threatening, and rapid transfusion and immediate surgical intervention are necessary. Nonresponse to fluid administration indicates persistent blood loss. Blood preparation should be emergency blood release. Type and cross-match of blood can be used for additional resuscitation in transient responders.
RECOMMENDED READINGS
Olson SA, Reilly MC, eds. Acetabular and Pelvic Fractures. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2007:15-42.
Advanced Trauma Life Support for Doctors, ed 8. Chicago, IL, American College of Surgeons, 2008.
RESPONSES FOR QUESTIONS 71 THROUGH 74
- Retrograde intramedullary (IM) nailing
- Open reduction and internal fixation (ORIF) with screws alone
- Locking condylar plate
- Circular external fixation
- Lateral and medial plates
Which treatment option listed is best for each patient described?

71A

B
C

D

A 54-year-old healthy man with the condition seen in Figures 71a through 71d
- Retrograde intramedullary (IM) nailing
- Open reduction and internal fixation (ORIF) with screws alone
- Locking condylar plate
- Circular external fixation
- Lateral and medial plates

Question 38

Regarding bone erosion in rheumatoid arthritis, which of the following statements is true?





Explanation

TNF, IL1 and IL-6 receptor blockade helps to slow/arrest bone erosion in RA and is also effective in reducing synovitis.
Cytokines TNF, IL-1 and IL-6 are key players in RA. TNF stimulates migration of osteoclast precursors from the bone marrow into the periphery, and stimulates expression of surface receptors to facilitate differentiation. In the joint, M-CSF and RANKL stimulate differentiation towards osteoclasts. Final differentiation into bone-resorbing osteoclasts is achieved following contact with the bone surface.
Schett et al. reviewed bone erosions in RA. They state that the main triggers of bone erosion are synovitis, RANKL, and anti-citrullinated protein antibodies. In RA, there is an abundance of osteoclasts in bone erosions, but a paucity of mature osteoblasts, suggesting the presence of molecules that block osteoblast differentiation.
Ideguchi et al. investigated whether repair of erosions occurs in patients with rheumatoid arthritis (RA) treated with conventional disease-modifying anti-rheumatic drugs (DMARDs). They detected repair of erosions in 10.7% of RA patients treated with DMARDs. They recommend the use of DMARDs to reduce disease activity and thus reduce erosions.
Illustration A shows the action of antirheumatic drugs on osteoclast differentiation and bone erosion.

Question 39

What neurologic structure is most at risk when performing intramedullary screw fixation of a fifth metatarsal base fracture?





Explanation

DISCUSSION: The sural nerve and its terminal branches course through the lateral hindfoot and midfoot area and are directly at risk in surgeries involving the peroneal tendon complex and the fifth metatarsal.  The first branch of the lateral plantar nerve originates in the tarsal tunnel region and courses across the plantar heel area to innervate the abductor digiti minimi; it is not at direct risk with fifth metatarsal surgery.  The saphenous, superficial peroneal, and deep peroneal nerves are not at risk anatomically with a lateral midfoot incision.
REFERENCES: Donley BG, McCollum MJ, Murphy GA, Richardson EG: Risk of sural nerve injury with intramedullary screw fixation of fifth metatarsal fractures: A cadaver study.  Foot Ankle Int 1999;20:182-184.
Lawrence SJ, Botte MJ: The sural nerve in the foot and ankle: An anatomic study with clinical and surgical implications.  Foot Ankle Int 1994;15:490-494.

Question 40

Figure 53 shows the MRI scan of a 53-year-old carnival worker who has pain and swelling in the left shoulder as a result of attempting to stop a roller coaster car with his arm. Examination reveals decreased ROM, apprehension, and inability to move the dorsum of his hand away from his back. Treatment should consist of





Explanation

This patient has an acute tear of the subscapularis tendon both by MRI and physical exam. Treatment of choice is open repair. Nonoperative treatment is not indicated.

Question 41

Figure 2 shows the lateral radiograph of an 8-year-old boy who sustained an acute injury to the elbow after falling down the stairs. Management should consist of





Explanation

DISCUSSION: The patient has a flexion-type olecranon fracture, and the integrity of the extensor mechanism is disrupted.  With this degree of displacement, closed reduction and extension casting would not be adequate.  The strongest construct is an oblique screw across the fracture site, with a tension band.  Healing is rapid in this age group; therefore one of the heavy absorbable sutures can be used as the tension band.  Two parallel pins with the stainless steel tension band wire (AO technique) can be used but requires wire dissection for removal.  Once the fracture is healed, the single screw can be removed easily with only a small incision.  The presence of the screw, across the apophysis, has not been shown to produce any significant growth disturbance.  Use of a large intramedullary screw would not be advisable because of the small size of the proximal fragment.
REFERENCES: Murphy DF, Greene WB, Gilbert JA, Dameron TB Jr: Displaced olecranon fractures in adults: Biomechanical analysis of fixation methods.  Clin Orthop 1987;224:210-214.
Chambers HG, Wilkins KE: Part IV: Fractures of the proximal radius and ulna, in Rockwood CA Jr, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4.  Philadelphia, PA, Lippincott-Raven, 1996, vol 3, pp 629-630.

Question 42

A 72-year-old man has had persistent pain after undergoing a hemiarthroplasty 18 months ago. Radiographs are shown in Figures 50a and 50b. What is the most likely cause of his problem?





Explanation

DISCUSSION: The radiographs demonstrate a rapid erosion of the bipolar component into the acetabulum.  Although acetabular erosion is more common with unipolar hip arthroplasties, it can occur with bipolar components.  Haidukewych and associates noted a very low erosion rate but none in the first 2 years.  The second finding on the radiographs is the linear radiolucency progressing from the joint toward the end of the stem at the cement-bone interface suggesting chronic infection or diffuse loosening.  The persistent pain since implantation also suggests chronic infection.  High activity levels and osteoporosis do not lead to acetabular erosion in the first 2 years after hemiarthroplasty.  While the cement technique is suboptimal, loosening and erosion should not be expected from this alone.  An oversized bipolar head would extrude and not erode.
REFERENCES: Haidukewych GJ, Israel TA, Berry DJ: Long-term survivorship of cemented bipolar hemiarthroplasty for fracture of the femoral neck.  Clin Orthop Relat Res 2002;403:118-126.
Lestrange NR: Bipolar hemiarthroplasty for 496 hip fractures.  Clin Orthop Relat Res 1990;251:7-19.
Callaghan JJ, Dennis DA, Paprosky WG, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, p 158.

Question 43

Corticosteroids inhibit the formation of effectors of the inflammatory pathway via inhibition of





Explanation

Corticosteroids prevent the formation of the pre-inflammatory mediator arachidonic acid from cell membrane phospholipids by inhibiting phospholipase A2. This inhibition prevents the earliest step in the inflammatory cascade. Arachidonic acid proceeds through the lipoxygenase pathway to produce leukotrienes, responsible for autocrine and paracrine signaling, or through the cyclooxygenase pathway (either COX-1 or COX-2) to produce prostaglandins. Thromboxane A2, present in platelets, activates phospholipase C which causes cellular effects resulting in platelet aggregation. Prostacyclin and thromboxane A2 work as antagonists. Prostacyclin is released from endothelial cells, inhibiting platelet aggregation and causing vasodilation.

Question 44

Figures 21a and 21b show the clinical photograph and radiograph of a 15-year-old girl who has a deformity of her feet. Her parents are concerned because there is a family history of Charcot-Marie-Tooth disease. The patient reports some mild instability of the ankle and has noticed mild early callosities; however, she is not having any significant pain. Coleman block testing reveals a forefoot valgus and supple hindfoot. She has weakness to eversion and dorsiflexion. Initial management should consist of





Explanation

DISCUSSION: Initial management of a young patient with a cavovarus deformity of the foot and a family history of Charcot-Marie-Tooth disease should focus on mobilization and strengthening of the weakening muscular units and an accommodative insert.  Surgical intervention should be delayed until progression of the deformity begins to cause symptoms and/or weakness of the muscular units, resulting in contractures of the antagonistic muscle units.
REFERENCES: Pinzur MS: Charcot’s foot.  Foot Ankle Clin 2000;5:897-912.
Holmes JR, Hansen ST Jr: Foot and ankle manifestations of Charcot-Marie-Tooth disease.  Foot Ankle 1993;14:476-486.
Thometz JG, Gould JS: Cavus deformity, in The Child’s Foot and Ankle.  New York, NY, Raven Press, 1992, pp 343-353.

Question 45

A 17-year-old boy underwent open reduction and internal fixation of a navicular fracture 5 days ago. A follow-up examination now reveals a tensely swollen foot with erythema and multiple skin bullae. The patient is febrile and has marked pain with palpation of the entire forefoot and hindfoot. What is the next step in management?





Explanation

DISCUSSION: Necrotizing fasciitis is a rapidly progressive soft-tissue infection with the potential to threaten both life and limb.  Patients who are immunocompromised (HIV infection, diabetes mellitus, alcohol abuse) are at increased risk.  However, any patient in the immediate postoperative phase is susceptible to wound infection.  Early detection is the key.  Necrotizing fasciitis is primarily a surgical problem that requires urgent debridement and broad-spectrum IV antibiotics.  Rapid diagnosis and prompt treatment help to reduce mortality, which may approach 30%.  Debridement of the bullae and observation are not indicated.  Although elevation and close follow-up may be warranted early on, in this patient, surgical debridement is the next step.
REFERENCES: Ault MJ, Geiderman J, Sokolov R: Rapid identification of group A streptococcus as the cause of necrotizing fasciitis.  Ann Emerg Med 1996;28:227-230.
McHenry CR, Piotrowski JJ, Pentrinic D, Malangoni MA: Determinants of mortality for necrotizing soft-tissue infections.  Ann Surg 1995;221:558-563.

Question 46

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





Explanation

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

Question 47

15% to 2.5%. Acute Charcot arthropathy almost always appears with signs of inflammation. Profound unilateral swelling, an increase in local skin temperature (generally, an increase of 3° to 7° above the nonaffected foot's skin temperature), erythema, joint effusion, and bone resorption in an insensate foot are present. These characteristics, in the presence of intact skin and a loss of protective sensation, are often pathognomonic of acute Charcot arthropathy. Cellulitis is an infection of the skin. Examination would reveal erythema, edema, and pain. Osteomyelitis is an infection of the bone. Examination may reveal edema, drainage, and pain.






Explanation

Whereas all of the factors will have an impact on frame rigidity and stability, the single biggest factor is the pin diameter because it has an exponential effect.
Which of the following clinical scenarios represents the strongest indication for locked plating technique in a 70-year-old woman?
Segmentally comminuted ulnar fracture
Simple diaphyseal fracture of the humerus
Transverse midshaft displaced clavicle fracture
Periprosthetic femur fracture distal to a well-fixed total hip arthroplasty
Schatzker 2 fracture of the tibia with severe joint depression and comminution
Locking screw fixation is a relatively new option in the armamentarium of orthopaedic surgeons treating fractures. The understanding of the biomechanics, implications to healing, and optimal indications and surgical techniques is still in evolution. A periprosthetic proximal femur fracture with a stable prosthesis is best treated with open reduction and internal fixation with locking proximal fixation with or without cerclage cables. Diaphyseal fractures treated with compression plating or bridge plating can be treated well with conventional implants unless osteoporosis is severe. An AO/OTA B-type partial articular fracture is also better suited to standard buttress plating with periarticular rafting lag screws. Locking fixation is not always required for a transverse displaced midshaft clavicle fracture.
What is the post-amplification product of reverse transcription polymerase chain reaction (RT-PCR)?
RNA
DNA
Protein
Mitochondria
Immunoglobulins
Reverse transcription polymerase chain reaction (RT-PCR) is a variant of polymerase chain reaction (PCR) used in molecular biology to generate many copies of a DNA sequence from fragments of RNA. The RNA strand is first reverse transcribed into its DNA complement, followed by amplification of the resulting DNA using polymerase chain reaction. Polymerase chain reaction amplifies short segments of DNA by using the temperature stable DNA polymerase enzyme.
A 63-year-old woman falls from standing and lands on her right hand. She complains of deformity and wrist pain. Radiographs are provided in Figure A. Following closed reduction, the patient inquires whether she has osteoporosis and if she is likely to have another fracture. In counselling the patient, which of the following is the strongest predictor for a future fracture from low energy trauma?
Bone mineral density T-score < -2.5
Low vitamin D levels
Family history of osteoporosis
History of a prior fragility fracture
Ten year history of oral prednisone use
Each of the answer choices is a risk factor for subsequent fragility fracture, but patient history of a prior fragility fracture is the strongest predictor.
Bouxsein et al reviews the proper care, diagnosis, and prevention of fragility fractures. History of a fragility fracture is the greatest predictor of a future fracture from low energy trauma. Appropriate care includes not only treatment of the fracture itself, but also proper evaluation to identify the etiology of the fracture and appropriate intervention to rectify the underlying pathology. Evaluation includes bone densitometry, lab testing of Vitamin D and calcium.
A T-score compares your bone density to the optimal peak bone density for your gender. It is reported as number of standard deviations below the average. A T-score of -1 to -2.5 is considered osteopenia, and a risk for developing osteoporosis. A T- score of less than -2.5 is diagnostic of osteoporosis.
Long-term alendronate (Fosamax) use for osteoporosis has been associated
with which of the following?
Scurvy
Detached retina
Uterine carcinoma
Osteonecrosis of the femoral head
Diaphyseal femoral insufficiency fractures
Alendronate is a bisphosphonate that inhibits the ruffled border of the osteoclast. When used long term, this class of medication prevents the normal bone remodeling process. Long-term use has recently been shown to be associated with insufficiency fractures of the femur. Osteonecrosis of the jaw has been described but not in other anatomic locations. Scurvy occurs because of a lack of vitamin C and use of bisphosphonates is not associated with
uterine cancer or a detached retina.
Implants composed of polylactic acid are excreted by what system after they are absorbed?
Hepatic
Renal
Respiratory
Gastrointestinal
Polylactic acid suture and suture anchors are popular bioabsorbable orthopaedic implants. This material undergoes hydrolysis of the ester background in vivo. Resulting lactic acid enters the tricarboxylic acid (Krebs)
cycle and is excreted as carbon dioxide by the lungs. Polyglycolic acid and poly(p- dioxanone) may also be excreted by the kidneys.
A patient sustains a grade III medial collateral ligament injury. One year later, when compared to collagen in an uninjured ligament, an increase is likely in the
gross number of fibers.
proportion of type III fibers.
cross-linking.
mass and diameter of fibers.
Studies on animal models have shown that there is a change in collagen fiber type and distribution early in the healing process. There is a higher portion of type III fibers than in
normal ligament initially, but this ratio returns to normal about 1 year after the injury occurs. Healing ligaments show an increased number of collagen fibers, but the number of mature collagen cross-links is
45% of predicted value after 1 year. There is also a decrease in the mass and diameter of the collagen fibers.
Sclerostin and dickkopf-1 (Dkk-1) are direct inhibitors of what pathway related to bone and/or cartilage regulation?
Bone morphogenetic protein (BMP)/SMAD pathway
Receptor activator of nuclear factor kappa beta (RANK)/RANK ligand (RANKL) pathway
Wnt/Beta-catenin (&#223;-catenin) pathway
Parathyroid hormone (PTH) pathway
Dkk-1 and sclerostin are proteins that inhibit the binding of the Wnt molecule to receptors LRP5/6. In the absence of sclerostin and Dkk-1, Wnt binds to its receptor, which in turn inhibits phosphorylation of the ß-catenin. The unphosphorylated ß-catenin then builds up in the cytoplasm of the cell, allowing it to be transported to the nucleus of the cell. Once in the nucleus, ß- catenin will lead to upregulation of a series of proteins involved in osteoblast formation differentiation. Knocking out or inhibiting sclerostin or Dkk-1 results  in increased bone mass secondary to constitutive activation of the Wnt/ß- catenin pathway. The other responses are not directly affected by Dkk-1 or sclerostin. RANKL and RANK are expressed on osteoblasts and osteoclasts, respectively, and are involved in osteoblast-mediated osteoclast activation. BMPs work through SMADs to cause osteoblastic differentiation, and there is reported crosstalk between the Wnt and BMP pathways (but this is an indirect link). Finally, PTH at physiologic levels binds to osteoblasts, causing a series of events that lead to osteoblast-mediated osteoclast activation and subsequent increased bone resorption.
During endochondral ossification of the growth plate, the process that most contributes to the longitudinal growth of long bones is
chondrocyte apoptosis.
chondrocyte hypertrophy.
chondrocyte proliferation.
growth plate matrix synthesis.
The growth plate is divided into 5 distinct zones: reserve, proliferative, maturation, hypertrophy, and vascular invasion. During growth-plate chondrocyte hypertrophy, intracellular volume and an increase in chondrocyte height are responsible for most growth of long bones. Other factors that contribute to bone growth are chondrocyte proliferation and matrix synthesis, but to a lesser degree than chondrocyte hypertrophy. Growth plate chondrocytes undergo programmed cell death (apoptosis) after hypertrophy
takes place.
Bacterial resistance to tetracycline is confirmed by ribosome protection, tetracycline modification, and
altered RNA polymerase.
altered membrane binding protein.
increased drug efflux.
DNA gyrase mutation.
Mutations of bacterial DNA gyrase can decrease the effectiveness of quinolones. Altered membrane-binding protein is observed with resistance to ?
-lactam antibiotics. Tetracyclines are antibiotics that inhibit bacterial growth by stopping protein synthesis. Three specific mechanisms of tetracycline
resistance have been identified: increased tetracycline efflux, ribosome protection, and tetracycline modification. Alteration of RNA polymerase is found in resistance to rifampin.
A 14-year-old boy has failed physical therapy management for Scheuermann kyphosis, and an extension thoracolumbosacral orthosis brace is recommended. The boy and his parents are told that the brace will force his thoracic spine into normal sagittal alignment and put the anterior vertebral bodies of the thoracic segment into tension, which will induce bone growth and normalization of wedge- shaped
vertebrae. What name is associated with this process?
Hooke's law
Kirchhoff's law
Wolff's law
Heuter-Volkmann principle
The Heuter-Volkmann principle shows that bone placed in longitudinal tension will tend to stimulate longitudinal growth, and that compressive longitudinal forces inhibit longitudinal growth, making this response the best choice. Hooke's law relates to stress being proportional to strain and is not directly related to bone growth. Kirchhoff's laws apply to electrical circuit design. Wolff's law states that bone remodels in response to mechanical stress, with the correlate that increased stress causes increased growth, and decreased stress leads to bone loss.
A tendon repair is thought to be weakest during which phase of tendon healing?
Inflammatory
Proliferation
Maturation
Remodeling
Healing after a tendon repair or rupture has the following stages: inflammatory, cellular proliferation, and remodeling. During the inflammatory phase, neutrophils and macrophages migrate into the injury site and release chemotactic factors that recruit fibroblasts. A tendon is thought to be weakest
5 to 21 days after repair, which coincides with the inflammatory phase. During the proliferative phase, inflammatory cells secrete cytokines and growth
factors (platelet-derived growth factor, insulin-like growth factor, bone morphogenetic protein (BMP)-12 and BMP 13, and transforming growth factor- beta) that promote differentiation of fibroblasts. Fibrosis and decreased cellularity are the hallmarks of the remodeling stage.
A 4-year-old boy has bilateral genu varum and is in the fifth percentile for height for his age. A younger sister has less severe genu varum. Radiographs reveal physeal cupping and widening on both the distal femur and proximal tibia. Laboratory studies show sodium 145 mEq/L (reference range, 136-142 mEq/L), potassium 4.0 mEq/L (reference range, 3.5-5.0 mEq/L), calcium 9.0 mg/dL (reference range, 8.2-10.2 mg/dL), phosphorous 2 mg/dL (reference range, 4-

Question 48

Compared with cobalt-chromium, the biomechanical properties of titanium on polyethylene articulation in total hip replacement result in





Explanation

DISCUSSION: The surface hardness of titanium is low compared with that of cobalt-chromium alloys.  Titanium articulations are easily scratched, resulting in a significantly increased rate of wear and debris production.  The wear and resulting lysis can also result in an increased rate of loosening.
REFERENCES: Simon SR (ed): Orthopaedic Basic Science.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 449-486.
Agins HJ, Alcock NW, Bansal M, et al: Metallic wear in failed titanium-alloy total hip replacements: A histological and quantitative analysis.  J Bone Joint Surg Am 1988;70:347-356.
Robinson RP, Lovell TP, Green TM, Bailey GA: Early femoral component loosening in DF-80 total hip arthroplasty.  J Arthroplasty 1989;4:55-64.

Question 49

What changes in muscle physiology would be expected in an athlete who begins a rigorous aerobic program for an upcoming marathon?





Explanation

DISCUSSION: Muscle fibers can be categorized grossly into two types.  Type I muscle, also known as slow-twitch muscle, is responsible for aerobic, oxidative muscle metabolism.  It has a much lower strength and speed of contraction than fast-twitch type II muscle but is significantly more fatigue resistant.  With training for endurance sports, the type I muscle undergoes adaptive changes to the increased stress.  Increases in capillary density, oxidative capacity, mitochondrial density, and subsequent fatigue resistance are all observed changes.  Hypertrophy of type IIb muscle is seen in strength training. 
REFERENCES: Simon SR (ed): Orthopaedic Basic Science.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1994, pp 89-125.
Thayer R, Collins J, Noble EG, et al: A decade of aerobic endurance training: Histological evidence for fibre type transformation.  J Sports Med Phys Fitness 2000;40:284-289.

Question 50

A 30-year-old woman injured the ring finger of her nondominant hand while playing baseball 5 weeks ago. She now reports pain and limited motion of the proximal interphalangeal (PIP) joint. A lateral fluoroscopy image is shown in Figure 36. Treatment of the PIP joint should consist of





Explanation

DISCUSSION: The patient has a neglected PIP joint fracture-dislocation with comminution involving more than 40% of the volar articular surface of the middle phalanx.  Volar plate arthroplasty has been advocated for the treatment of acute unstable and chronic dorsal fracture-dislocations.  The volar plate is incised laterally and released from the collateral ligaments.  The volar fragments of the middle phalanx are removed and a trough is created for advancement of the volar plate, which is secured with sutures secured on the dorsum of the middle phalanx beneath the extensor mechanism.   
REFERENCES: Dionysian E, Eaton RG: The long-term outcome of volar plate arthroplasty of the proximal interphalangeal joint.  J Hand Surg Am 2000;25:429-437.
Eaton RG, Malerich MM: Volar plate arthroplasty of the proximal interphalangeal joint: A review of ten years’ experience.  J Hand Surg Am 1980;5:260-268.
Deitch MA, Kiefhaber TR, Comisar BR, et al: Dorsal fracture dislocations of the proximal interphalangeal joint: Surgical complications and long-term results. J Hand Surg Am 1999;24:914-923.

Question 51

While performing long fusion with osteotomies for a patient with adult scoliosis and sagittal plane deformity, the neurophysiologist reports a change in motor-evoked potentials in the lower extremities. What is the most appropriate next step?




Explanation

DISCUSSION
The use of intraoperative neuromonitoring is expanding, especially in the setting of deformity surgery. Changes in monitoring are concerning for the possibility of a neurologic injury; however, several other factors can alter signals. These include hypotension, changes in anesthesia depth and medications, the use of paralytic agents, and technical issues such as leads falling out or becoming disconnected. If a change in neuromonitoring signals is noted, these factors should be checked first to rule out false-positive findings. If this does not correct the problem, the wound should be explored to ensure there is no compression on the neural elements. Finally, if the deformity has been corrected, some of the correction can be released in an attempt to improve the signals. A wake-up test is difficult to perform and does not provide specific information regarding the location of the problem or how to correct it. Steroids may be used depending on surgeon preference, but should not be used until neurologic injury is ruled out. Any neuromonitoring changes always necessitate immediate investigation.
RECOMMENDED READINGS
Ziewacz JE, Berven SH, Mummaneni VP, Tu TH, Akinbo OC, Lyon R, Mummaneni PV. The design, development, and implementation of a checklist for intraoperative neuromonitoring changes. Neurosurg Focus. 2012 Nov;33(5):E11. doi: 10.3171/2012.9.FOCUS12263. PubMed PMID: 23116091. View Abstract at PubMed
Malhotra NR, Shaffrey CI. Intraoperative electrophysiological monitoring in spine surgery. Spine (Phila Pa 1976). 2010 Dec 1;35(25):2167-79. doi: 10.1097/BRS.0b013e3181f6f0d0.
Review. PubMed PMID: 21102290. View Abstract at PubMed

Question 52

A 17-year-old high school gymnast who has peripatellar knee pain has been unable to practice on a consistent basis for the past 3 years. She denies any specific injury events. Physical therapy for modalities, quadriceps strengthening, and hamstring stretching provide temporary relief. A trial of patellar taping significantly reduces her pain. Examination reveals an 15-degree Q angle, moderate lateral facet tenderness, negative patellar apprehension, and the inability to evert the patella. Radiographs show a moderate lateral patellar tilt. Treatment should now consist of





Explanation

DISCUSSION: The patient has patellofemoral stress and a tight lateral retinaculum that has failed to respond to nonsurgical management; therefore, the most appropriate treatment includes an arthroscopic lateral retinacular release.  A patellar restraining brace may aggravate the peripatellar pain by increasing pressure on the lateral facet.  There is no evidence of patellar instability or significant malalignment; therefore, medial retinacular repair or a tibial tubercle transfer is not indicated.  A modified Maquet tibial tubercle elevation would be considered only for significant patellofemoral arthrosis.
REFERENCES: Gambardella RA: Techical pitfalls of patellofemoral surgery.  Clin Sports Med 1999;18:897-903.
Post WR: Clinical evaluation of patients with patellofemoral disorders.  Arthroscopy 1999;15:841-851.

Question 53

  • Which of the following acetabular/femoral head components would be expected to show an optimal combination of linear and volumetric wear?





Explanation

The size of the femoral head and the calculated mean annual rate of volumetric wear has a significant relationship. Rate of volumetric wear was highest in assoc with 32 mm femoral lowest in assoc with 22 mm heads. The predominant mechanisms of wear of the polyethylene were abrasion and adhesions rather than fatigue-cracking or delamination on the subsurface. Decreased thickness of the polyethylene has an adverse effect on the rate of wear of the metal-backed components. Rate of linear wear is highest in assoc. with 22-mm heads and lowest in relation to 32-mm heads, so the optimal size of a femoral head should be 28 mm where there is minimal linear and volumetric wear.

Question 54

A patient who underwent an L5-S1 hemilaminotomy and partial diskectomy for radiculopathy 3 weeks ago now reports increasing leg and back pain with radicular signs. An axial T2-weighted MRI scan is shown in Figure 97a, an axial T1-weighted MRI scan is shown in Figure 97b, and a contrast enhanced T1-weighted MRI scan is shown in Figure 97c. What is the most appropriate management for the patient's symptoms? Review Topic





Explanation

The MRI scans show a recurrent disk herniation. There is no increase fluid signal or enhancement to suggest infection or any other pathologic process. There is no infection; therefore, IV antibiotics and debridement are not indicated. Similarly, a pseudomeningocele is not present. In addition, with progressive weakness, physical therapy is not appropriate. A revision diskectomy is useful for recurrent radiculopathy.

Question 55

A 17-year-old high school football player sustains a traumatic anterior shoulder dislocation, resulting in a small bony Bankart lesion and small Hill-Sachs lesion. The patient undergoes an arthroscopic Bankart repair with incorporation of the bone fragment and returns to play football the following year. He has a recurrent dislocation at football practice but decides to finish the football season before considering additional treatment. He sustains nine additional dislocations, with the last dislocation occurring while sleeping.What diagnostic test is most appropriate when planning revision surgery?




Explanation

A failed bony Bankart repair with multiple dislocations can further erode the anteroinferior glenoid, changing the sagittal morphology of the glenoid into an “inverted pear.” Quantitative bone loss is best evaluated by CT scan with 3-D reconstructions and subtraction of the humeral head. MRI and ultrasonography can assist in evaluating soft-tissue injury, but they are not as helpful in determining bone loss compared with a CT scan. An arthrogram alone is not sufficient to evaluate bone loss. Bone loss >30% necessitates glenoid augmentation with either a Latarjet procedure or iliac crest bone grafting. A revision arthroscopic or open Bankart repair with capsular shift or remplissage do not address bone loss. The Latarjet procedure can effectively restore stability with glenoid bone loss and after failed stabilizing procedures. Patients with pain before surgery  are
 more likely to have pain after surgery. Age and activity level are lesser influences on satisfaction.

Question 56

Figures 1 through 4 are the CT scans and intraoperative image of a 17-year-old boy who sustained a gunshot wound to his knee. What is the most appropriate definitive surgical management for his articular cartilage defect?




Explanation

The images show a full-thickness cartilage defect with significant bony involvement >4 cm2. Microfracture should be considered for lesions <2 cmwithout an underlying osseous defect. Autologous chondrocyte implantation, although used for lesions between 1 and 10 cm2, should be restricted for defects with minimal (<8 mm depth) bone loss. Osteochondral allograft transfer with the mosaicplasty technique (transfer of multiple plugs) would be well-suited for this large defect with significant osseous involvement. Dejour trochleoplasty is performed for patellar instability to correct trochlear dysplasia and would not be indicated in this case.                          

Question 57

A 15-year-old girl reports a 6-month history of activity-related knee pain and swelling. A radiograph, MRI scan, and biopsy specimen are shown in Figures 21a through 21c. What is the most likely diagnosis?





Explanation

DISCUSSION: The epiphyseal location on the radiograph and MRI scan and the histologic findings of polyhedral cells separated by a chondroid matrix with pericellular, lattice-like “chicken wire” calcification all suggest chondroblastoma.  Although giant cell tumors of bone typically occupy an epiphyseal location, they are rare in children and when present are often metaphyseal in skeletally immature patients.  Enchondromas and osteoblastomas are generally metaphyseal and, along with giant cell tumors, have very different histology than seen here.  Chondromyxoid fibromas are typically metaphyseal in location.
REFERENCES: Huvos AG: Bone Tumors: Diagnosis, Treatment, and Prognosis.  Philadelphia, PA, WB Saunders, 1991, pp 295-313.
Lin PP, Thenappan A, Deavers MT, et al: Treatment and prognosis of chondroblastoma.  Clin Orthop Relat Res 2005;438:103-109.

Question 58

A 22-year-old woman sustains the injury seen in Figure 12 as a result of a motor vehicle crash. What factor is most closely associated with development of osteonecrosis?





Explanation

A displaced femoral neck fracture in a young patient is considered a surgical urgency and prompt anatomic reduction and internal fixation is recommended. There are a few studies that have specifically looked at the rate of osteonecrosis in this patient population. A review of femoral neck fractures in patients ages 15 to 50 years revealed that the incidence of osteonecrosis in displaced fractures was 27% compared with 14% in nondisplaced fractures. The quality of the reduction also influenced the rate of osteonecrosis. Time to reduction, type of implant, presence or absence of capsulotomy, and location of the fracture are not associated with osteonecrosis risk.
(SBQ12TR.90) A 40-year-old male sustained the injury seen in Figure A, and subsequently underwent the procedure shown in Figure B. One hour post-operatively he starts to complain of pain in the operative leg, and the pain is unchanged with active or passive stretch. The external dressing is released with little resolution of symptoms. His blood pressure is 115/78 mm Hg with compartment pressures in the leg measuring 31 to 35 mm Hg. His ABI index is 1.1 in the leg. What would be the next step in management? Review Topic

MRI angiography of leg
Four-compartment fasciotomy
Follow-up examination the following day
Continued monitoring and serial examinations
EMG study
The patient is at risk for developing compartment syndrome of the leg. The next most appropriate step would be to support his systemic blood pressure and monitor compartment pressures.
A clinical assessment is the diagnostic cornerstone of acute compartment syndrome. However, the intracompartmental pressure measurement has been advocated to help confirm the diagnosis in patients where there remains uncertainty after clinical exam.
An absolute compartment pressure >30 mm Hg or a difference in diastolic pressure and compartments pressure (delta p) <30 mm Hg may help to confirm the necessity for fasciotomy. However, the treatment of early compartment syndrome should be to initially improve the limbs perfusion pressure gradient. This can be done by treating underlying factors such as hypotension, coagulopathy, or vascular compromise due to either a true vascular injury or artificially by external compression. Frequent reassessment is then critical to effectively manage these patients. If clinical diagnosis persists despite these efforts, urgent fasciotomy would be considered.
McQueen looked at 116 patients with tibial diaphyseal fractures who had continuous monitoring of anterior compartment pressure for 24 hours. They found that using an absolute pressure of 30 mmHg would have resulted in 50 patients (43%) treated with unnecessary fasciotomies. They conclude using a differential pressure of 30 mmHg is a more reliable indicator of compartment syndrome.
White et al. looked at 101 patients with tibial fractures with satisfactory Delta P measurements. THey found that patients with elevated intramuscular pressures >30 mm Hg after tibial fracture do not have a greater incidence of complications than those with low pressures, so long that Delta P <30 mm Hg.
Figure A shows a Shatzker V tibial plateau fracture. Figure B shows fixation of fracture seen in Figure A.
Incorrect Answers:
30 mm Hg or persistently elevated absolute compartment pressures.. Answer 3: It would not be appropriate to leave this patient with impending compartment syndrome.
(SBQ12TR.57) A 56-year-old right hand dominant attorney falls from standing and sustains the closed injury shown in Figure A. The treating surgeon elects to fix her fracture using a plate and screw construct. Based on the available imaging, which of the following fracture characteristics best justifies this fixation choice? 

Fracture displacement
Intra-articular fracture extension
The fracture extends distal to the coronoid
Oblique fracture line
Fracture comminution
This patient has a displaced, intra-articular, comminuted olecranon fracture. Comminution is an indication for plate fixation.
Most displaced olecranon fractures are treated operatively. Options include tension band constructs, intramedullary screws, plate and screw fixation or fragment excision with triceps advancement. Any construct relying on inter-fragmentary compression (tension band, intramedullary screws) requires a non-comminuted fracture pattern. Plate fixation is indicated in the setting of comminution, extension past the coronoid, or in the setting of associated instability.
Bailey et al. retrospectively reviewed 25 patients who underwent plate fixation of displaced olecranon fractures. Twenty-two of 25 patients had good or excellent outcomes. Five of 25 patients (20%) of patients required plate removal for symptomatic hardware. The authors concluded that plate fixation was an effective treatment for displaced olecranon fractures, with good functional outcomes.
Figure A shows a displaced, comminuted olecranon fracture without evidence of propagation past the coronoid.
Incorrect answers:
congruity but does not dictate implant selection. Answer 3. Extension distal to the coronoid is an indication for plate fixation but there is no evidence of such extension on the radiograph shown Answer 4. This fracture is comminuted, without a distinct fracture line.

Question 59

Figures 34a and 34b show the radiographs of a 28-year-old man who fell on his outstretched arm with significant force while mountain biking. The nerve deficit most likely to occur would result in weakness of





Explanation

DISCUSSION: The patient has a Monteggia fracture-dislocation (proximal ulnar fracture and radial head dislocation).  The posterior interosseous nerve branch of the radial nerve is the most likely to be injured and could result in weakness of thumb extension and finger metacarpal extension.  Considerably less likely are injuries to the more proximal radial nerve branches supplying the extensor carpi radialis longus and brevis, resulting in weak wrist extension; the ulnar nerve supplying the digital intrinsics, resulting in weak finger abduction; the anterior interosseous branch of the median nerve, resulting in weakness of the flexor pollicis longus; and the distal median nerve, resulting in weakness of thumb opposition.
REFERENCES: Bado JL: The Monteggia lesion.  Clin Orthop 1967;50:71-86.
Jupiter JB, Leibovic SJ, Ribbans W, Wilk RM: The posterior Monteggia lesion.  J Orthop Trauma 1991;5:395-402.

Question 60

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





Explanation

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

Question 61

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 62

Which of the following statements best describes the process of articular cartilage degeneration in osteoarthritis?






Explanation

DISCUSSION: Inflammation, overload, or decreased matrix production may lead to cartilage degeneration. During the second stage of articular cartilage degeneration with osteoarthritis, there is increased chondrocyte activity with proliferation and increased production of extracellular matrix. At the same time, there is an increase in catabolic activity with removal of damaged matrix to facilitate matrix remodeling. Chondrocyte repair response decreases with aging. Matrix degradation includes decreased proteoglycan production, less aggregation, and shorter glycosaminoglycan chains.
REFERENCE: Buckwalter JA, Mankin HJ, Grodzinsky AJ: Articular cartilage and osteoarthritis. Instr Course Lect 2005;54:465-480.

Question 63

Figures 15a and 15b show the radiographs of an 18-year-old mountain biker who came off of a 15-foot ramp and sustained an injury to his ankle. Because the local rural hospital had no orthopaedic surgeon available, he was transported to a Level 1 emergency department 10 hours after his initial injury. Examination reveals that the injury remains closed. Management should consist of





Explanation

DISCUSSION: High-energy tibial pilon fractures involve disruption of the soft-tissue envelope with significant lower extremity edema.  Definitive reconstruction of the comminuted distal tibia should be delayed for at least 7 days to allow edema to dissipate, lowering the risk of skin necrosis.  An external fixator is the best method to keep the ankle at anatomic length while preventing skin necrosis. Ligamentotaxis will hold the fragments reduced to allow the edema to dissipate.  CT may be obtained in traction to localize the individual fragments and plan surgical incisions and subsequent fixation.  Short leg casting will not provide adequate ligamentotaxis to hold the fragments reduced and prevent skin compromise.  Primary fusion of the ankle in an unstable tibial pilon fracture is prone to a poor result from nonunion or malunion. 
REFERENCES: Tornetta P III, Weiner L, Bergman M, et al: Pilon fractures: Treatment with combined internal and external fixation.  J Orthop Trauma 1993;7:489-496.
Sirkin M, Sanders R, DiPasquale T, Herscovici D Jr: A staged protocol for soft tissue management in the treatment of complex pilon fractures.  J Orthop Trauma 1999;13:78-84.

Question 64

An otherwise healthy 26-year-old woman is involved in a high speed motor vehicle accident and sustains the injury shown in Figure 54 to her dominant right arm. Appropriate treatment of this injury complex includes





Explanation

DISCUSSION: This Galeazzi fracture is an injury that requires surgical treatment in an adult.  The algorithm includes anatomic reduction of the radial shaft and closed reduction of the DRUJ with assessment of stability.  If the DRUJ remains unstable, supination of the wrist may reduce the DRUJ.  If not, either open or closed reduction with pinning is undertaken.  The closer the radius fracture is to the DRUJ, the more likely it is to be unstable.
REFERENCE: Rettig ME, Raskin KB: Galeazzi fracture-dislocation: A new treatment-oriented classification.  J Hand Surg Am 2001;26:228-235.

Question 65

Figures 11a and 11b show the radiographs of a 50-year-old man who was struck by a car. Treatment should consist of





Explanation

DISCUSSION: The patient has a displaced femoral neck fracture.  Although the treatment remains controversial, most clinicians advocate either a closed or open reduction in younger active patients.  Achieving an anatomic reduction is necessary to avoid loss of reduction, nonunion, or osteonecrosis.  An acceptable reduction may have up to 15° of valgus angulation and 10° of posterior angulation.  Parallel multiple screws or pins are the most common method of internal fixation.  Prosthetic replacement is generally reserved for older and less active individuals.
REFERENCES: Callaghan JJ, Dennis DA, Paprosky WG, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, pp 97-108.
Asnis SE, Wanek-Sgaglione L: Intracapsular fractures of the femoral neck: Results of cannulated screw fixation.  J Bone Joint Surg 1994;76A:1793-1803.

Question 66

Figures 1 and 2 are the CT and MRI scans of a patient with shoulder instability.  Contrasting  these  two  imaging  techniques  for  decision making in shoulder instability would suggest




Explanation

A 43-year-old woman is involved in a motor vehicle collision. She sustains the isolated injury shown in the radiograph in Figure 1. Her neurovascular examination  is  compromised. What  is  the  most  likely deficit?

A.   Inability to flex the distal interphalangeal joint of the index finger

B.   Positive Froment’s sign

C.   Weakness with wrist extension

D.   Decreased capillary refill

Question 67

A 29-year-old man reports a 2-week history of severe neck pain after being struck sharply on the back of the head and neck while moving a refrigerator down a flight of stairs. Initial evaluation in the emergency department revealed no obvious fracture and he was discharged in a soft collar. Neurologic examination is within normal limits, and radiographs taken in the office are shown in Figures 21a through 21c. Subsequent MRI scans show intra-substance rupture of the transverse atlantal ligament. What is the most appropriate treatment option at this time? Review Topic





Explanation

Dickman and associates classified injuries of the transverse atlantal ligament into two categories. Type I injuries are disruptions through the substance of the ligament itself. Type II injuries render the transverse ligament physiologically incompetent through fractures and avulsions involving the tubercle of insertion of the transverse ligament on the C1 lateral mass. Type I injuries are incapable of healing without supplemental internal fixation. Type II injuries can be treated with a rigid cervical orthosis with a success rate of 74%. Surgery may be required for type II injures that fail to heal with 3 to 4 months of nonsurgical management.
(SBQ13PE.82) A renal ultrasound should be obtained in a patient with which of the following diagnoses? Review Topic
Congenital pseudoarthrosis of the clavicle
Accessory navicular
Congenital scoliosis
Charcot-Marie-Tooth Disease
Congenital curly toe
A renal ultrasound should be obtained in a patient with congenital scoliosis.
Congenitial scoliosis has a prevalence that is estimated at 1% to 4% in general population. It is associated with systemic anomalies in up to 61% of cases. The most common anomalies are cardiac defects, genitourinary defects and spinal cord malformations. As such, additional imaging of these systems should be considered in the initial work-up of these patients.
Ruf et al. retrospectively investigated 56 consecutive operative cases of congenital scoliosis. The average age at surgery was 9.9 years (1.5–17 years). There was one wound complication, 2 hardware failures, 1 revision and no neurological complications. They concluded that one-stage posterior hemivertebra resection and instrumentation was safe in this population.
Xu et al. examined the efficacy of selective partial hemivertebra excision via posterior-only approach in 17 adolescent patients with congenital kyphoscoliosis. There were no postoperative infections and no neurological complications. They concluded that this approach may be most successful in patients aged 9 to 14 years old, with the Risser sign grades from 0–3 and Cobb angles <60°.
Illustration A from Erol et al (UPOJ, Vol 15, 2002;37-42) shows a diagram of 'types' of congenital scoliosis based on the morphology of the vertebrae.
Incorrect Answers:

Question 68

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





Explanation

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

Question 69

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




Explanation

DISCUSSION
In this scenario, the flexion gap needs to be increased. Increase in flexion gap can be accomplished by downsizing the femoral component and increasing posterior tibial slope. In posterior cruciate-retaining TKA procedures, recession or release of the posterior cruciate ligament can loosen the flexion gap, allowing for an increase in flexion. Flexing the femoral
component tightens the flexion gap, and downsizing the tibial insert thickness decreases flexion and extension gaps, while resection of the distal femur only increases the extension gap.

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

Question 70

What neurovascular structure is at greatest risk when creating a proximal anterolateral elbow arthroscopy portal? Review Topic





Explanation

The radial nerve is 4 to 7 mm from the anterolateral portal, which is placed 1 cm anterior and 3 cm proximal to the lateral epicondyle. The posterior interosseous nerve can lie 1 to 14 mm from the portal site.

Question 71

A 60-year-old woman has a mass in the right scapula. Figures 25a and 25b show a CT scan and a biopsy specimen. The cells are lymphocyte common antigen positive, Ewing’s specific antigen (CD99) negative, and keratin negative. What is the next step in management?





Explanation

DISCUSSION: The clinical history, CT scan, and histology are most consistent with a lymphoma of bone.  An important part of the staging is bone marrow aspiration and biopsy.  The other studies listed are not indicated.  Lymphoma of bone, when localized, is usually treated with chemotherapy and radiation therapy and has excellent survival rates.  Widespread lymphoma has a worse prognosis.
REFERENCES: Finiewicz K, van Biesen K: Non-Hodgkins lymphoma, in Golomb H, Vokes E (eds): Oncologic Therapies, ed 2.  Berlin, Germany, Springer, 2003, pp 295-318.
Lems P, Primus G, Anastas J, Doherty D, Montag AG, Peabody TD, Simon MA: Oncologic outcomes of primary lymphoma of bone in adults.  Clin Orthop 2003;415:90-97.

Question 72

A patient has a large T11-T12 disk herniation that is causing substantial compression of the spinal cord. The patient reports walking imbalance over the past few weeks. Examination of the patient's reflexes is likely to show Review Topic





Explanation

The patient has a large thoracic disk herniation that is causing spinal cord compression. The history of gait imbalance suggests that the patient has thoracic level myelopathy. Assuming that the patient does not have lumbar stenosis, compression of the spinal cord at the T11-T12 level will cause upper motor neuron findings distal to it. Hyperreflexia of the upper extremities would suggest that the patient has cervical spinal cord compression. In this patient, the upper extremity reflexes should be normal. Most likely, the patient will exhibit hyperreflexia in the lower extremities, which is an upper motor tract sign.

Question 73

During impaction of a cementless acetabular component, the posterior column was fractured and found to be displaced. Which of the following is considered the most appropriate surgical option?





Explanation

DISCUSSION: Acetabular bone loss presents a challenge during reconstruction.  A cementless hemispherical cup can be used in most patients provided that the acetabular rim, particularly the posterior column, is intact.  When the posterior column is disrupted, fixation with a reconstruction plate and/or the use of an antiprotrusio cage is recommended.  The latter is particularly important when the posterior column is fractured and displaced, such as in this patient.  Under these circumstances, reduction of the fracture and application of an antiprotrusio cage is recommended.  In this particular type of case, some surgeons may elect to retain the hemispherical cup and apply an antiprotrusio cage over the cup (“cage over cup” technique).
REFERENCES: Berry DJ: Antiprotrusio cages for acetabular revision.  Clin Orthop 2004;420:106-112.
Peterson CA, Lewallen DG: Periprosthetic fracture of the acetabulum after total hip arthroplasty.  J Bone Joint Surg Am 1996;78:1206-1213.

Question 74

A 42-year-old woman complains of ankle pain with weightbearing for the last 2 years. She recalls spraining her ankle more than 10 years ago. She plays tennis and regularly walks 5 miles a day for exercise, but has had to give up these activities over the last few months because of pain. Examination reveals limitation in ankle dorsi- and plantar flexion. A course of non-operative management has been unsuccessful. Which of the following options will most likely provide pain relief and allow her to return to her previous activity level?





Explanation

This young, active patient has ankle valgus following previous trauma. A corrective supramalleolar osteotomy of the tibia will provide pain relief and improve range of motion, allowing return to sports.
Supramalleolar osteotomy may be performed for varus (medial opening wedge or lateral closing wedge) or valgus (lateral opening wedge or medial closing wedge) ankles. They are suited for near-normal ROM minimal talar-tilt or varus heel alignment, asymmetric ankle arthritis (confined to medial or lateral compartment; corresponding to Takakura Stage II or IIIA for medial ankle arthritis).
Pagenstert et al. looked at realignment surgery for posttraumatic arthritis in 35 patients. For valgus ankles, they performed 18 medial closing wedge and 1 lateral opening wedge osteotomies. For varus ankles, they performed 7 medial opening wedge and 4 lateral closing wedge osteotomies. There was improvement in pain (7/10 to 3/10), ROM (33° to 38°) and Takakura score (2.3 to 1.3).
Lee et al. described supramalleolar osteotomy for medial arthritis in 16 patients. There was improvement in AOFAS score (62 to 82), Takakura stage (2.9 to 2.3), tibial-anterior surface angle (85 to 100°). Patients with low postoperative talar tilt (TT) had better clinical and radiographic results than those with high TT. Greater postoperative heel valgus predicted for postoperative subfibular pain.
Figure A shows valgus alignment at the ankle. Illustration A shows the same ankle following medial closing wedge supramalleolar osteotomy. Illustration B is a table showing the Takakura classification. Illustration C demonstrates correction of the tibial-anterior surface angle (TAS) following supramalleolar osteotomy.
Incorrect Answers:

Question 75

A 28-year-old man has had a 2-week history of right posterior leg pain, with numbness and tingling in the same distribution. He denies any problems with bowel or bladder function. Examination shows intact motor strength in his bilateral lower extremities, with numbness to light touch in the lateral border of his right foot. Over the past 2 weeks, his leg pain has improved significantly. MRI scans are shown in Figures 57a and 57b. What is the most appropriate course of management? Review Topic





Explanation

The patient has an L5-S1 disk herniation, which has a favorable prognosis without surgical intervention. Most acute lumbar disk herniations resolve with nonsurgical management. The most appropriate course of initial treatment should be analgesics and activity modification, followed by rehabilitation as the symptoms allow. Although the MRI scan indicates a large disk herniation, he has no symptoms or signs that would warrant urgent surgical decompression. Planned elective diskectomy should be considered only if nonsurgical management fails to provide relief. Epidural injections could be considered if the initial course of treatment fails to give the patient significant relief. Posterior laminectomy and fusion is not indicated without the presence of instability.
(SBQ12SP.9) A 62-year-old male underwent posterior spinal instrumented fusion for degenerative lumbar spondylolithesis one year ago. He presents to office complaining of persistent lower back pain. The pain initially improved but over the last 6 months he has had recurring pain at the site of the surgery primarily with activity. He denies back pain at rest or night pain. Physical examination reveals a well healed wound and no physical abnormalities. He has no tenderness to palpation to the thoracic or lumbar spine. He has no neurological deficits. His laboratory results show an erythrocyte sedimentation rate (ESR) = 8 mm/h and C-reactive protein (CRP) = 3 mg/L at the last visit which are both within normal limits. Figure A shows a series of radiographs from his pre-operative, 3 month post-operative and 1 year post-operative clinic visits, respectively. Which of the following investigations would best confirm the suspected underlying diagnosis? Review Topic

MRI of lumbar spine
Repeat ESR/CRP and whole body bone scan
CT of lumbar spine
Dynamic flexion/extension plain film radiographs
Dynamic lateral bending plain film radiographs
This patient has clinical and radiographic features of failed spinal arthrodesis. CT scan have been shown to be the most relable method for assessing spinal fusion postoperatively.
Reported rates of nonunion following posterior spinal fusion range from 0-70%. Rates are variable due to the various operative techniques, underlying diagnoses as well as asymptomatic patients. Non-union may lead to changes in alignment, spinal instability and potential neurological injury. Static radiographs have long been used as a practical method of fusion assessment, but these tend to significantly overestimate the presence of a solid fusion. Lack of movement at a fused segment, on dynamic views, does not confirm fusion. CT offers excellent bony resolution and are less affected by metal artifact compared to MRI.
Patel et al. showed that tobacco use, malnutrition, oral anti-inflammatory use, multilevel fusion, prior spine surgery, and sagittal imbalance are all risk factors for spinal nonunion.
Mok et al. looked at erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels after spinal surgery and compared their usefulness as predictors of infectious complications in the early postoperative period. They found that CRP is more applicable, predictable, and responsive in the early postoperative period compared with ESR. Using a second rise or failure to decrease as expected for CRP is sensitive for infection.
Shelby et al. reviewed the radiological assessment of spinal fusion. They comment that fine-cut imaging, multiplanar reconstruction, and metal artifact reduction have increased the ability to assess fusion on CT.
Figure A shows a series of lateral radiographs of the lumbar spine with posterior spinal instrumentation. Illustration A shows a lateral CT scan image of multi-level pseudoarthrosis after posterior spinal instrumented fusion. Illustration B shows an
intra-operative
view
of
spinal
pseudoarthrosis
(white
arrow).
Incorrect
(SBQ12SP.19) A 41-year-old male presents with acute onset of low back pain that started when he was trying to lift a heavy box while helping his brother move apartments two days ago. The pain has been severe enough to cause him to miss work yesterday. He has no neurologic deficits. What are the chances he will return to work within 6 weeks? Review Topic
1 80 to 90%
2 70 to 80%
3 60 to 70%
4 50 to 60%
5 40 to 50%
Most adults (up to 80%) will experience an episode of low back pain in their lifetime. In those whose pain is severe enough to cause them to miss work, 60 to 70% will return by 6 weeks, and 80 to 90% will return by 12 weeks.
Low back pain is common in adults. Most patients experience resolution of symptoms quickly and have no lasting loss of function. However, 5 to 10% develop chronic pain. Recurrence of pain is common, and is part of the natural history, occurring in 20 to 72% of patients. After 12 weeks, return to work rates are slow.
Shen et al. review the nonoperative management of acute and chronic low back pain. The authors note that none of the available interventions has been proven by high quality large randomized controlled trials. The authors believe that low dose oral
steroids are safe in the short term and that injection therapy should not be used without a reasonable presumptive diagnosis.
Madigan et al. review the management of lumbar degenerative disease. The authors emphasize that the majority of patients improve within 6 weeks with or without treatment. For patients that do not, the authors do not recommend epidural injection, as there are no good studies to support their use in the treatment of discogenic back pain. When surgical treatment is indicated they state that arthrodesis is the gold standard, although the long term results of total disk arthroplasty are being elucidated.
Illustration A shows a table of available non-operative treatment modalities for back pain. Illustration B shows a list of possible diagnoses associated with acute low back pain, with those associated with neurogenic pain italicized. Illustration C shows a list of 'red flag' symptoms indicating serious/emergent causes of low back pain.
Incorrect
2:
Longer
to than
90%

Question 76

A football player sustains a traumatic anterior inferior dislocation of the shoulder in the last game of the season. It is reduced 20 minutes later in the locker room. The patient is neurologically intact and has regained motion. If the patient undergoes arthroscopic evaluation, what finding is seen most consistently?





Explanation

DISCUSSION: In an acute first-time dislocation, arthroscopy has been shown to reveal a Bankart lesion in most shoulders.  The classic finding of labral detachment from the anterior inferior glenoid along with occasional hemorrhage within the inferior glenohumeral ligament is the most common sequelae of a traumatic anterior inferior dislocation.  Acute treatment, if chosen, is repair of the labral tissue back to the glenoid plus or minus any capsular plication to address potential plastic deformation of the glenohumeral ligament.  Acute treatment of a patient sustaining a first-time dislocation remains controversial.  The potential indications may be patients whose dislocation occurs at the end of a season and when the desire to minimize risk of future instability outweighs the risks of surgical intervention.
REFERENCES: Taylor DC, Arciero RA: Pathologic changes associated with shoulder dislocations: Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations.  Am J Sports Med 1997;25:306-311.
DeBerardino TM, Arciero RA, Taylor DC, et al: Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes: Two- to five-year follow-up.  Am J Sports Med 2001;29:586-592.
Bottoni CR, Wilckens JH, DeBerardino TM, et al: A prospective, randomized evaluation of arthroscopic stabilization versus nonoperative treatment in patients with acute, traumatic,

first-time shoulder dislocations.  Am J Sports Med 2002;30:576-580.

Question 77

Figure 29a shows the clinical photograph of a 26-year-old woman who has had the leg deformity since birth. She reports difficulty with walking and weight bearing and notes increased discomfort and swelling when the leg is dependent. She denies any history of trauma or family history of a similar disorder. Examination reveals a fixed equinovarus deformity of the foot but no evidence of a limb-length discrepancy. No other cutaneous findings or soft-tissue masses are noted. Sagittal and axial T1- and T2-weighted MRI scans are shown in Figures 29b and 29c. What is the most likely diagnosis?





Explanation

DISCUSSION: Because the MRI scans show marked dilation and proliferation of lymphatic channels that completely involve all the leg muscles and the clinical photograph shows the severe swelling associated with this disease, the most likely diagnosis is lymphangiomatosis.  Poliomyelitis affects the anterior horn cells and manifests as muscle atrophy.  Neurofibromatosis can have a similar clinical appearance but usually is associated with other systemic and cutaneous findings.  Congenital band syndrome results in amputated or shortened extremities.  Chronic venous stasis disease usually is not associated with joint contractures, and typically it affects older individuals.  Surgical excision is the only known treatment; this patient underwent an above-knee amputation.  
REFERENCES: Berquist TH (ed): MRI of the Musculoskeletal System, ed 3.  Philadelphia, PA, Lippincott Raven, 1997, p 771.
Enzinger FM, Weiss SW: Soft Tissue Tumors, ed 3.  St. Louis, MO, Mosby Year Book, 1995, p 688.

Question 78

A 45-year-old woman sustains an injury to her lower leg. Examination reveals that there is a deformity with no neurologic or vascular problems. The skin is intact. Radiographs are shown in Figures 46a and 46b. Which of the following factors would make closed management the least appropriate choice for this injury?





Explanation

DISCUSSION: All the factors listed, with the exception of an ipsilateral femoral fracture, are representative of a low-energy stable tibial shaft fracture that will do well with closed reduction and immobilization in a long leg cast, followed by weight bearing as tolerated and then a functional brace or patellar tendon bearing cast until union is achieved.  Shortening will not increase from that seen on these initial radiographs.  The spiral fracture provides a broad surface for healing, and the fibular fracture at another level indicates a stable soft-tissue envelope which, with the immobilization device, will stabilize the fracture reduction.  An ipsilateral femoral fracture is a strong indication to surgically stabilize both fractures.
REFERENCES: Trafton PG: Tibial shaft fractures, in Browner BD (ed): Skeletal Trauma, ed 3.  Philadelphia, PA, WB Saunders, 2003, pp 2153-2169.
Martinez A, Sarmiento A, Latta LL: Closed fractures of the proximal tibia treated with a functional brace.  Clin Orthop 2003;417:293-302.

Question 79

Figures below show the radiographs obtained from a 68-year old man with progressively worsening right side hip pain over the last 8 months. He is 6 feet tall, with a BMI of 51 kg/m2  and reports that his index total hip arthroplasty was performed 8 years ago. The preoperative work-up includes negative infectious laboratory results. What is the most appropriate surgical plan for revision of the femoral component in this patient?




Explanation

DISCUSSION:
Submit Answer
The patient’s radiographs demonstrate varus femoral remodeling around a broken cylindrical, distally fixed femoral stem. Proximal femoral remodeling around loose or fractured stems occurs in 21% to 42% of femoral revisions, based on the definitions outlined by Foran and associates. In definition 1, varus femoral remodeling occurs when the template falls within 2 mm of the endosteal cortex of the metaphysis on templating with a diaphyseal engaging stem. In definition 2, varus femoral remodeling = when the template crosses the lateral femoral cortex proximally. Based on the templating or drawing a line from the isthmus proximally along the lateral cortex, implantation of a straight stem would perforate the cortex proximally, indicating varus femoral remodeling. An extended trochanteric osteotomy would aid in the removal of the well-fixed distal segment and enable the safe insertion of the new femoral component. The approach is not the concern in this case, because extended trochanteric osteotomies have been described from the posterior and direct lateral approaches with excellent outcomes and union rates. The key is that the  extended  osteotomy  is  necessary  and  not  a  trochanteric  slide  or  standard  (shorter  or  incomplete trochanteric) osteotomy. These types would not provide access to the well-fixed distal stem, nor would they afford a straight tube in which to insert a new femoral component.

Question 80

-Sideline examination of this patient showed no cervical pain or tenderness; motor and sensory function were normal; and his pupils were equal, round, and reactive. He was alert and oriented to the score of game, time on the clock, and current quarter of play. His iliac crest had mild tenderness but no swelling or crepitus. The player states that he has a slight headache and is no longer dizzy. What is the most appropriate treatment?




Explanation

DISCUSSION FOR QUESTIONS 24 AND 25
Although this player limps off the field, the fact that he felt dizzy, had a headache, and did not initially recognize that he was playing in the third quarter indicates that he sustained a concussion. The player should be kept out of the game until a cognitive examination and repeat physical assessment is completed.Even if his physical symptoms have resolved, a certain period of time has expired, or he states that he is“ready,” he should not be returned to play prior to this assessment. Sending the patient to an emergency department should be considered only after this assessment and appropriate initial sideline treatment is initiated. The Consensus Statement on Concussion in Sport recommends that no athlete with concussion symptoms be returned to same-day play. This patient still has a slight headache, but even if this resolved he should not return to the game. Adolescents and high school athletes may have neurophysiological deficits that may not be evident on the sideline, or they may have a delayed onset of symptoms. A graduated return to play for future games is recommended.
CLINICAL SITUATION FOR QUESTIONS 26 THROUGH 29
A 32-year-old woman has a 2-year history of progressively worsening right groin pain that is exacerbated by activity. She reports no traumatic injury and an extensive work-up by her gynecologist has ruled out an intrapelvic source of her pain. The patient is a recreational athlete and exercises regularly in the gym.The pain is preventing her from performing these activities. She reports no catching or locking symptoms.Her examination reveals a physically fit female (BMI of 20) with limited right hip range of motion. She has no tenderness to palpation around the hip. While lying supine and bringing her hip into progressive flexion with internal rotation and adduction, her groin pain is reproduced. She has normal limb lengths and demonstrates weakness secondary to pain with hip flexion on the affected side.

Question 81

Figures 35a and 35b show the radiographs of a patient who underwent debridement of a chronically infected, fully constrained knee prosthesis and now reports pain and instability despite bracing. History reveals that the patient has had no drainage since undergoing the last debridement 6 months ago. A C-reactive protein level and aspiration are negative for infection. Treatment should now consist of





Explanation

DISCUSSION: The radiographs show a significant loss of the proximal anterior tibial cortex, consistent with an extensively damaged or deficient extensor mechanism.  Such a deficit precludes insertion of another knee arthroplasty.  Arthrodesis is the treatment of choice for this patient and is indicated for loss of the extensor mechanism and knee instability.  A recent report on arthrodesis following removal of an infected prosthesis showed a union rate of 91% using a short intramedullary nail.  Insertion of an antibiotic-impregnated PMMA spacer is not indicated because the rationale for using a spacer is to maintain a space for reinsertion of another prosthesis.  Reconstruction of the extensor mechanism would not address the loss of the joint.  Amputation is the final treatment option if the arthrodesis fails.  
REFERENCES: Rand JA: Alternatives to reimplantation for salvage of the total knee arthroplasty complicated by infection.  J Bone Joint Surg Am 1993;75:282-289.
Lai KA, Shen WJ, Yang CY: Arthrodesis with a short Huckstep nail as a salvage procedure for failed total knee arthroplasty.  J Bone Joint Surg Am 1998;80:380-388.
Damron TA, McBeath AA: Arthrodesis following failed total knee arthroplasty: Comprehensive review and meta-analysis of recent literature.  Orthopedics 1995;18:361-368.

Question 82

Which of the following clinical scenarios represents an appropriate indication for convex hemiepiphysiodesis/hemiarthrodesis in the treatment of a child with a congenital spinal deformity?





Explanation

DISCUSSION: Convex hemiarthrodesis and hemiepiphysiodesis are procedures designed to gradually reduce curve magnitude in congenital scoliosis because of hemivertebrae.  They are used to surgically create an anterior and posterior bar to arrest growth on the convexity of the existing deformity.  Success of the technique is predicated on continued growth on the concave side of the deformity.  Prerequisites for this procedure include curves of limited length (less than or equal to five vertebrae), curves of reasonable magnitude (less than 70°), absence of kyphosis, concave growth potential, and appropriate age (younger than age 5 years).
REFERENCE: Winter RB, Lonstein JE, Denis F, Sta-Ana de la Rosa H: Convex growth arrest for progressive congenital scoliosis due to hemivertebrae.  J Pediatr Orthop 1988;8:633-638.  

Question 83

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





Explanation

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

Question 84

A 19-year-old male collegiate rower has a 3-month history of right shoulder pain. There was no inciting trauma prior to the onset of his pain. He also complains of weakness, particularly in abduction and overhead activity. Examination reveals no range-of-motion deficits. Strength testing of the right shoulder demonstrates 4/5 motor strength in forward elevation and abduction. His Beighton hypermobility score is 3/9. Figure 1 shows his scapular position during a wall pushup maneuver. An EMG would likely reveal damage to what nerve?




Explanation

Figure 1 reveals medial scapular winging secondary to weakness of the serratus anterior, which is innervated by the long thoracic nerve. Damage to the long thoracic nerve can occur via repetitive stretching, compression, or iatrogenic injury during a surgical procedure. Lateral thoracic winging is caused by weakness of the trapezius, which is innervated by cranial nerve XI (spinal accessory nerve). The direction of scapular winging is judged by the upper medial border of the scapula. Observation of a period of at least 6 months with serratus anterior strengthening while the nerve recovers is the mainstay of treatment for medial scapular winging.                       

Question 85

The patient undergoes further testing and it is discovered that the lesion encompasses 70% of the joint. What is the best next treatment option?




Explanation

DISCUSSION
A tarsal coalition is an abnormal connection of 2 or more bones in the foot. Although tarsal coalitions are present at birth, children and adults typically do not show signs of the disorder until early adolescence or later. The exact incidence of the disorder is hard to determine; however, it is caused by a gene mutation that affects cells that produce the tarsal bones. The 2 most common locations for tarsal coalitions are between the calcaneus and the navicular or between the talus and the calcaneus. It is estimated that 1 out of every 100 people may have a tarsal coalition. In 50% of cases, both feet are affected. Tarsal coalitions are rarely discovered until symptoms arise. Symptoms may include stiff and painful feet, a rigid flatfoot, or increased pain or a limp with high-level activities. Upon examination, symptoms may include tenderness in the area of the coalition, loss of motion, rigid flat feet, and arthritic changes of the joint. Imaging studies begin with radiographs. A CT scan can provide bony detail for imaging tarsal coalitions and determining the extent of the coalition and any accompanying degenerative change. MRI can provide details of the soft tissues. Treatment includes nonsurgical care including rest, orthotics, a temporary boot or cast, and injections. Surgical options include resection with interposition of muscle or fatty tissue from another area of the body or fusions when large (exceeding 50% of the joint), more severe coalitions are encountered.
RECOMMENDED READINGS
Lemley F, Berlet G, Hill K, Philbin T, Isaac B, Lee T. Current concepts review: Tarsal coalition. Foot Ankle Int. 2006 Dec;27(12):1163-9. Review. PubMed PMID: 17207452. View Abstract at PubMed
Badgley CE. Coalition of the calcaneus and the navicular. Arch Surg. 1927;15:75-88. Conway JJ, Cowell HR. Tarsal coalition: clinical significance and roentgenographic demonstration. Radiology. 1969 Mar;92(4):799-811. PubMed PMID: 5767760. View Abstract at PubMed
Herzenberg JE, Goldner JL, Martinez S, Silverman PM. Computerized tomography of talocalcaneal tarsal coalition: a clinical and anatomic study. Foot Ankle. 1986 Jun;6(6):273-

Question 86

Based on the MR arthrogram of the elbow shown in Figure 8, which of the following structures is torn?





Explanation

DISCUSSION: Based on the MR arthrogram in which gadolinium (bright on T1-weighted images) was injected into the joint space prior to imaging, the study shows a tear of the anterior band of the ulnar collateral ligament (UCL).  The disruption in the distal end of the UCL is outlined by contrast.  A small collection of contrast extravasation into the flexor musculature further confirms the presence of a tear.  The UCL has a broad-based attachment on the medial epicondyle and has a pointed or tapered attachment distally on the ulna.  Most UCL tears occur distally at the ulnar (coronoid) attachment.
MR arthrography provides improved sensitivity compared to conventional MRI, without contrast, for the detection of UCL pathology, particularly in the subacute or chronic setting.  After the soft-tissue edema and joint fluid associated with the injury have resolved, the torn end of the ligament may lie in contact with its adjacent attachment and create a false-negative appearance.  In this patient, a noncontrasted MR arthrogram showed no tear, yet the tear is apparent with intra-articular contrast and distention.  MR arthrography of the elbow also may be useful in detecting intra-articular bodies or in evaluation for loose osteochondral fragments or flaps.
REFERENCES: Morrey BF: Acute and chronic instability of the elbow.  J Am Acad Orthop Surg 1996;4:117-128.
Resnick D, Kang HS (eds): Internal Derangements of Joints: Emphasis on MR Imaging.  Philadelphia, PA, WB Saunders, 1997, pp 200-210.

Question 87

Which of the following is considered a contraindication to functional bracing for the treatment of humeral shaft fractures?





Explanation

DISCUSSION: Most closed humeral shaft fractures and fractures caused by a low-velocity hand gun can be managed nonsurgically with closed reduction and application of a coaptation splint followed by a functional brace.  Contraindications to use of the functional brace include:

1) massive soft-tissue or bone loss; 2) an unreliable or noncompliant patient; and 3) an inability to maintain acceptable fracture alignment of up to 20 degrees of anterior or posterior angulation, 30 degrees of varus or valgus angulation, and greater than 3 cm of shortening.

REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 271-286.
Pollock FH, Drake D, Bovill EG, Day L, Trafton PG: Treatment of radial neuropathy associated with fractures of the humerus.  J Bone Joint Surg Am 1981;63:239-243.
Sarmiento A. Zagorski JB, Zych GA, et al: Functional bracing for the treatment of fractures of the humeral diaphysis.  J Bone Joint Surg Am 2000;82:478-486.

Question 88

A 45-year-old recreational tennis player underwent arthroscopic decompression and mini-open repair of a small supraspinatus tendon tear 3 weeks ago after nonsurgical management failed to provide relief. He now has pain, swelling about the wound, erythema, and purulent drainage. The patient is returned to the operating room for irrigation, debridement, and cultures. What is the most common organism causing this infection?





Explanation

DISCUSSION: In a large series of mini-open rotator cuff repairs, an infection rate of at least 2% was found, with the majority of the infections caused by Propionibacterium acnes.  To prevent this complication, the shoulder should be re-prepped before the mini-open incision is made to prevent bacterial contamination from the arthroscopic procedure.
REFERENCES: Herrera MF, Bauer G, Reynolds F, et al: Infection after mini-open rotator cuff repair.  J Shoulder Elbow Surg 2002;11:605-608.
Settecerri JJ, Pitner MA, Rock MG, et al: Infection after rotator cuff repair.  J Shoulder Elbow Surg 1999;8:1-5.

Question 89

Figures 15a and 15b are the radiographs of a 28-year-old man who fell from a height and sustained an isolated closed diaphyseal femur fracture that was treated with reamed antegrade femoral nailing 8 months ago. He now reports persistent pain during ambulation. He smokes one pack of cigarettes per day but is otherwise healthy. He denies any infectious history or symptoms, and laboratory studies show a normal WBC count, erythrocyte sedimentation rate, and C-reactive protein. What is the most appropriate treatment?





Explanation

The patient has an uninfected symptomatic nonunion of the femur after reamed antegrade nailing with an appropriately sized implant. The fracture is well aligned and has some callus response indicating reasonable vascularity. Auto-dynamization has occurred via fatigue failure of the distal interlocking screws but the patient remains symptomatic and the fracture line is evident, consistent with nonunion. Reamed exchange nailing is preferred because it allows for improved mechanics via a larger diameter nail and repeat interlock and improved biologics via reaming which is felt to elicit an inflammatory reaction and generate bone graft in situ. Unfortunately, the results of exchange nailing are not as good in patients who smoke and smoking cessation should be counseled and encouraged. The data on external bone stimulation on unhealed fractures of the femur with an intramedullary nail present are lacking. In light of a benign clinical examination and history and normal blood work parameters with reference to infection, open biopsy of the nonunion prior to definitive surgical treatment is unwarranted. The patient has mechanical instability and bone grafting in situ will not address this issue in terms of promoting progression to union or allowing for improved function and less pain.

Question 90

What is the most significant prognostic factor in nontraumatic osteonecrosis of the humeral head?





Explanation

DISCUSSION: Use of systemic steroids has been implicated in the development of nontraumatic osteonecrosis of the humeral head.  Staging of the disease is most relevant to prognosis and treatment.  Cruess has described a widely accepted staging system.  Several authors have shown that patients who have a lower stage of disease (ie, stage I or II) have a much less likely chance of progression compared with those who are in the later stages (IV and V).
REFERENCES: Cruess RL: Osteonecrosis of bone: Current concepts as to etiology and pathogenesis.  Clin Orthop 1986;208:30-39. 
Cruess RL: Steroid-induced avascular necrosis of the humeral head: Natural history and management.  J Bone Joint Surg Br 1976;58:313-317.
Rutherford CS, Cofield RH: Osteonecrosis of the shoulder.  Orthop Trans 1987;11:239. 
Hattrup SJ, Cofield RH: Osteonecrosis of the humeral head: Relationship of disease stage, extent, and cause to natural history. J Shoulder Elbow Surg 1999;8:559-564.

Question 91

A 70-year-old woman with a body mass index (BMI) of 34 and a history of hypercholesterolemia has elected to undergo total hip arthroplasty. Her son recently learned he has factor V Leiden following an episode of pulmonary embolism. What are this patient's risk factors for thromboembolic disease?




Explanation

DISCUSSION:
Risk stratification is one of the most critical clinical evaluations to undertake before performing total joint arthroplasty. Many factors have been identified that increase the risk for venous thromboembolism (VTE) The major factors include previous VTE, obesity, type of surgery (such as total joint arthroplasty), hypercoagulable states, myocardial infarction, congestive heart failure, family history of VTE, and hormone replacement therapy. Hypercholesterolemia is not a risk factor for thromboembolic disease.

Question 92

A 15-year-old male jumps off a 6 foot ramp and lands awkwardly. His knee swells up immediately and he is taken to the emergency room. Figures A is a sagittal CT scan image. In the next 3 hours, he complains of increasing leg pain. This is likely because of injury to which of the following structures? Review Topic





Explanation

This child has a tibial tuberosity avulsion fracture with intraarticular extension. There is a risk for anterior compartment syndrome of the leg because of rupture of the anterior tibial recurrent artery located around the lateral border of the tibial tubercle. The vessels retract under the fascia, leading to bleeding into the anterior compartment.
Tibial tubercle fractures usually occur during aggressive quadriceps contraction during sports. The Ogden classification classifies this by site of fracture (Type I, through the tubercle; Type II, at the level of the tibial physis; Type III, extending through the anterior tibial epiphysis). Other complications include extensive soft tissue damage, periosteal stripping, vascular compromise and intra-articular damage.
Pandya et al. reviewed 41 tibial tubercle fractures. They found compartment syndrome or vascular compromise in nearly 10%. They found that the degree of injury was underestimated 50% of the time when classified using lateral radiographs alone. They recommend CT scan or MRI as an adjunct. If intra-articular involvement is seen, arthroscopy or open arthrotomy should be performed.
Pape et al. describe 2 case reports of anterior compartment syndrome after tibial tubercle fracture. The compartment syndrome occurs as a result of proximity of the tibial tubercle physis to the anterior tibial recurrent artery.
Figure A shows the sagittal reconstruction CT image showing intraarticular involvement. Illustrations A and B are axial and coronal CT images in the subchondral region showing the fracture line traversing the zone between fused and unfused physis (see Illustration C for physeal closure pattern). Illustration C shows the direction of closure of the proximal tibial physis. In the sagittal plane, the proximal tibial physis closes from posterior to anterior, then to the tubercle apophysis which closes from proximal to distal also. In the coronal plane, the physis closes from medial to lateral. In the axial plane, the physis closes from posteromedial to anterolateral. Illustration D shows the anterior tibial recurrent artery.
Incorrect Answers:

Question 93

A 68-year-old male presents with gait instability, clumsiness of the hands, and the MRI images shown in Figure A. You decide to proceed with surgical decompression. When planning your surgical treatment, it is important to note that compared to a posterior approach, the anterior procedure has: Review Topic





Explanation

Surgical decompression of cervical myelopathy via an anterior procedure has lower reported blood loss compared to a posterior procedure.
Cervical myelopathy has a progressive course and therefore if there is evidence of functional impairment surgical decompression is indicated. Either an anterior decompression or posterior decompression can be used depending on a variety of factors including number of levels involved and sagittal alignment of the cervical spine. In general, a posterior approach is used when three or more levels are involved and the spine is in neutral or lordotic alignment.
Fehlings et al. did a prospective study on the risks of complications associated with surgical treatment of cervical myelopathy. They found that combined anterior and posterior procedures had a significantly higher rate of complication than either anterior-only or posterior-only procedures. Posterior procedures had a higher rate of wound infections compared to anterior. They found no statistical difference in the over-all complication rate, incidence of C5 radiculopathy, or dysphagia between an anterior-only or posterior-only procedure.
Fehlings et al. did a prospective study on outcomes following surgical treatment of cervical myelopathy. At one year follow-up they found a significant improvement in mJOA score, Nurick grade, NDI score, and all SF-36v2 dimensions. With the exception of mJOA scores, these improvements were not statistically related to severity of disease.
Liu et al. performed a meta-analysis of outcomes following surgical decompression of cervical myelopathy. They found outcomes following anterior procedures were better than those for posterior procedures when there were less than 3 affected levels. With 3 or greater levels, no statistical difference in outcomes could be found between the two approaches. They note none of their reviewed publications represent high-quality prospective randomized trials.
Figure A is a sagittal MR image of the cervical spine showing multi-level degenerative disease with cord compression consistent with cervical myelopathy.
Incorrect Answers:

Question 94

During surgical treatment of the most common variation of distal femoral "Hoffa" fractures, which of the following orientations for screw fixation should be used?





Explanation

DISCUSSION: The most common variation of a Hoffa fracture is a coronal fracture of the lateral femoral condyle. The most appropriate screw placement of the above answer choices in the treatment of the most common Hoffa fracture variant would be anterior to posterior screws across the lateral condyle for fixation.
Hoffa fractures are coronally oriented fractures of the femoral condyles, with most occurring in the lateral condyle. They are commonly associated with high-energy fractures of the distal femur and can often be overlooked during the assessment and treatment of distal femur fractures. Hoffa fractures are best evaluated using CT scans.
Nork et al. studied the association of supracondylar-intercondylar distal femoral fractures and coronal plane fractures. Of 202 supracondylar-intercondylar distal femoral fractures, they found coronal plane fractures were diagnosed in 38%. A coronal fracture of the lateral femoral condyle was involved more frequently than the medial condyle. Eighty-five percent of these coronal fractures involved a single lateral femoral condyle.
Holmes et al. looked at five cases of coronal fractures of the femoral condyle. All cases received open reduction and internal fixation with lag screws through a formal parapatellar approach. They reported good results with all fractures healing within 12 weeks without complications with final range of motion at least 0 degrees to 115 degrees.


Question 95

  • To maximally resist apex anterior angulation in the tibia, the pins of a unilateral external fixator should be oriented in which of the following planes?





Explanation

The structural and geometric fixator properties that best neutralize the prevailing anteroposterior and transverse bending moments at a tibial fracture site were analyzed in anatomic specimens. Clinically and mechanically, anterior unilateral frames were most effective, particularly when applied with relatively stiff components with a maximal spread between the pins in each main bony fragment and with placement of the longitudinal rod.

Question 96

Figure 7 shows the MRI scan of a 23-year-old competitive rugby player who has anterior ankle pain and swelling. He states that he has been playing for many years and has sprained his ankle several times. Examination will reveal what specific hallmark feature?





Explanation

DISCUSSION: The history and MRI findings indicate the presence of anterior tibiotalar osteophytes.  This is frequently observed in soccer, rugby, and football athletes who play on grass or turf surfaces and repetitively push off and change directions.  Examination may reveal an effusion but no loss of subtalar motion.  A positive external rotation (Klieger) test is described as pain at the distal ankle with external rotation of the foot and is observed in patients with syndesmosis sprains.  This patient may have an increased anterior drawer because of a history of sprains; however, this finding is not specific for anterior impingement of tibiotalar osteophytes.  The most specific finding on physical examination is pain with forced dorsiflexion.
REFERENCES: Ogilvie-Harris DJ, Mahomed N, Demaziere A: Anterior impingement of the ankle of the ankle treated by arthroscopic removal of bony spurs.  J Bone Joint Surg Br 1993;75:437-440.
Cannon LB, Hackney RG: Anterior tibiotalar impingement associated with chronic ankle instability. J Foot Ankle Surg 2000;39:383-386.

Question 97

Figure 36a shows the current radiograph of a 65-year-old woman who slipped and fell. History reveals that prior to the fall she was actively functioning without pain. Figure 36b shows a radiograph obtained 1 year ago. Based on the fracture pattern, the failure is most likely related to





Explanation

DISCUSSION: The radiograph shows a fracture distal to the prosthesis in a stable, apparently well-fixed prosthetic stem.  The well-fixed prosthesis-bone composite is stiff, creating a modulus mismatch between the proximal and distal femur.  Therefore, the risk of fracture, particularly in osteoporotic bone, is increased at this level.  Revision of the stem to a longer construct is unnecessary, and standard plate and screw fixation has been shown to yield union rates of greater than 90%.  Nonsurgical treatment of fractures distal to the tip of the prosthesis results in high nonunion rates, reported to be from 25% to 42%.  
REFERENCES: Johansson JE, McBroom R, Barrington TW, Hunter GA: Fracture of the ipsilateral femur in patients with total hip replacement.  J Bone Joint Surg Am 1981;63:1435-1442.
Bethea JS III, DeAndrade JR, Fleming LL, Lindenbaum SD, Welch RB: Proximal femoral fractures following total hip arthroplasty.  Clin Orthop 1982;170:95-106.
Garbuz DS, Masri BA, Duncan CP: Periprosthetic fractures of the femur: Principles of prevention and management, in Cannon WD Jr (ed): Instructional Course Lectures 47.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 237-242.

Question 98

A 77-year-old man with diabetes mellitus has had a nonhealing Wagner grade I ulcer under the medial sesamoid for the past 3 months. He smokes tobacco regularly. He has undergone several debridements and total contact casting. Examination reveals no palpable pulses. He has no erythema or purulence, and he is afebrile. Radiographs reveal no abnormalities. What is the best initial diagnostic test to help determine why the ulcer has failed to heal?





Explanation

DISCUSSION: The best initial test for this patient is to assess the vascular supply to the foot.  An elderly smoker with diabetes mellitus has a high risk of peripheral vascular disease.  Decreased weight bearing has not been successful.  Although a bone scan might be helpful, it would take secondary consideration to the patient’s vascular supply, especially in the absence of any acute infection.  Monofilament testing would help diagnosis neuropathy, which is a root cause behind the ulcer forming, but does not prevent it from healing. The Thompson’s test is used to diagnosis an Achilles tendon rupture.  
REFERENCE: Brodsky JW: Evaluation of the diabetic foot.  Instr Course Lect 1999;48:289-303.

Question 99

Which one of the following lower extremity amputations requires a soft-tissue balancing procedure to prevent deformity following amputation? Review Topic





Explanation

The Lisfranc level amputation removes the attachment of the peroneus brevis (base of the fifth metatarsal) and the peroneus longus (base of the first metatarsal), creating a varus deformity due to unopposed overpull by the tibialis anterior and posterior muscles. An anterior tibialis tendon transfer may be necessary. Other possible tissue balancing choices include posterior tibialis transfer and lengthening of the gastrocsoleus complex. Another option is to leave the base of the fifth metatarsal attached to preserve the eversion pull of the peroneus brevis. All the other amputations do not require soft-tissue balancing procedures to prevent deformities. However, adherence to the prescribed surgical techniques for reattachment of major muscle groups is important for optimizing limb strength and function.

Question 100

The posterior horn of the medial meniscus receives its primary blood supply from what artery?





Explanation

DISCUSSION: The middle genicular artery supplies the posterior capsule and intracapsular structures (anterior cruciate ligament, posterior cruciate ligament, posterior horns of the meniscus).  The medial and lateral inferior geniculates anastomose anteriorly to form a capillary network to supply the fat pad, synovial cavity, and patellar tendon.  The lateral superior and inferior genicular arteries supply the lateral retinaculum.
REFERENCES: Insall J, Scott WN: Anatomy, in Surgery of the Knee, ed 3.  Philadelphia, PA, Churchill Livingstone, 2001, pp 64-70.
Scapinelli R: Vascular anatomy of the human cruciate ligaments and surrounding structures.  Clin Anat 1997;10:151-162.

Dr. Mohammed Hutaif
Medically Verified Content by
Prof. Dr. Mohammed Hutaif
Consultant Orthopedic & Spine Surgeon
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