Deformity, Foot & Fracture Orthopedic MCQs - Part 252

About This Board Review Set

This is Part 252 of the comprehensive OITE and AAOS Orthopedic Surgery Board Review series authored by Dr. Mohammed Hutaif, Consultant Orthopedic & Spine Surgeon.

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

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Two distinct learning modes are available:

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

Topics Covered in Part 252

This module focuses heavily on: Deformity, Foot, Fracture.

Sample Questions from This Set

Sample Question 1: -What is the etiology of this patient’s problem?...

Sample Question 2: Kinematic testing of patellofemoral motion demonstrates that malalignment that produces increased Q angle causes a shift of the patella laterally in the trochlear groove and is most pronounced during what phase of the flexion arc? Review To...

Sample Question 3: A 63-year-old male, with history of myocardial infarction, presents with buttock and leg pain. He states the pain is worse when climbing stairs, and is absent when walking down a hill. He reports when walking on a flat surface the pain begi...

Sample Question 4: What is the most common foot deformity associated with myelomeningocele?...

Sample Question 5: Figures 32a and 32b show the radiographs of a 13-year-old boy who sustained a fracture while playing football 1 week ago. Management at the time of injury included application of a cast and the use of crutches. A follow-up office visit reve...

Why Active MCQ Practice Works

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

Comprehensive 100-Question Exam

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Question 1

-What is the etiology of this patient’s problem?

Explanation

DISCUSSION FOR QUESTIONS 78 THROUGH 80
Little leaguer’s shoulder is an overuse condition of the proximal humeral physis. Patients report diffuse pain that is worse with throwing. Factors that contribute to the condition include excessive throwing,improper throwing mechanics, and muscle-tendon imbalance. Radiographs usually show widening of the proximal humeral physis, and, in more severe cases, metaphyseal demineralization or fragmentation. Surgical fixation is not required for healing. Treatment involves rest until symptoms resolve, followed by initiation of an interval throwing program. Pitching coaches should evaluate throwing mechanics and maintain pitch counts. The dominant shoulders of throwing athletes undergo adaptive changes, resulting in increased external rotation and decreased internal rotation. These changes occur secondary to softtissue and bony adaptations, including increased humeral retroversion. Ischemia has been implicated as a potential cause of osteochondritis dissecans lesions. Rotator cuff tendonitis presents with anterolateral shoulder pain that is worse with activity. Pain is reproduced with resisted supraspinatus testing, and radiograph findings are typically normal.
Adolescent shoulder injuries are often caused by subtle, atraumatic instability most often sustained in sports with overhead movements, including baseball. These symptoms are more likely to occur in athletes with evidence of increased soft-tissue laxity.

Question 2

Kinematic testing of patellofemoral motion demonstrates that malalignment that produces increased Q angle causes a shift of the patella laterally in the trochlear groove and is most pronounced during what phase of the flexion arc? Review Topic

Explanation

Dynamic patellofemoral joint contact measurements on cadaveric knees with simulated increased Q angle demonstrated that forces shifted to the lateral facet. The lateral shift in the patella was most pronounced from 40 to 90 degrees of flexion. At lower degrees of flexion, the lateral shift was significantly less. At higher degrees of flexion, the continued shift of the patella was not as pronounced.

Question 3

A 63-year-old male, with history of myocardial infarction, presents with buttock and leg pain. He states the pain is worse when climbing stairs, and is absent when walking down a hill. He reports when walking on a flat surface the pain begins after roughly 50 meters, but if he stops walking and remains standing upright, the pain resolves after a few minutes. He denies any leg pain when sitting and driving a car. These symptoms are most consistent with: Review Topic

Explanation

This clinical presentation is most consistent with vascular claudication.
Vascular claudication refers to the pain, aching or fatigue of the muscles of the buttocks, thigh and/or calf that occurs with exertion, and is related to a failure to meet muscular oxygen requirements, usually caused by peripheral vascular disease impeding blood flow to the peripheral muscles.
Neurogenic claudication is the classic symptom caused by lumbar spinal stenosis. Neurogenic claudication classically presents with bilateral buttock pain with upright activities, but seems to improve by postural changes that flex the lumbar spine. These posture changes are thought to increase the cross sectional area of the central canal, which relieves pressure on the affected area.
Issack et al. reviewed degenerative lumbar spinal stenosis. They state that patients with vascular claudication will have similar symptoms of leg cramping, whether ambulating or riding a stationary bicycle. In comparison, patients with neurogenic
claudication have diminished symptoms of claudication while positioned seated.
Young et al. reviewed the use of lumbar epidural/transforaminal steroids for managing spinal disease. They report that two thirds of acute low back pain episodes resolve within 7 weeks, so the utility and practice patterns regarding the timing and number of epidural/transforaminal steroid injections is usually based on expert opinion, rather than high level research evidence.
Illustration A shows an angiogram of a patients with normal (left) vs abnormal (right) arterial vasculature. Illustration B shows the typical MRI of a patient with spinal stenosis.
Incorrect

Question 4

What is the most common foot deformity associated with myelomeningocele?

Explanation

DISCUSSION: All of the above can be associated with myelomeningocele, but talipes equinovarus occurs in 50% to 90% of patients with myelomeningocele. Congenital vertical talus is rarely associated with any neuromuscular diseases other than myelomeningocele but is not the most common deformity in myelomeningocele.
REFERENCES: Stans AA, Kehl DK: The pediatric foot, in Baratz ME, Watson AD, Imbriglia JE (eds): Orthopaedic Surgery: The Essentials. New York, NY, Thieme, 1999, pp 702-703.
Lindseth RE: Myelomeningocele, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott, Williams & Wilkins, 2001,

pp 622-628.

Question 5

Figures 32a and 32b show the radiographs of a 13-year-old boy who sustained a fracture while playing football 1 week ago. Management at the time of injury included application of a cast and the use of crutches. A follow-up office visit reveals a normal neurologic examination, and the patient reports no discomfort with the cast and crutches. Management should now include

Explanation

DISCUSSION: Stable fractures and minimally displaced fractures in children can and should be treated by closed methods. Because loss of reduction is common, alignment of tibia fractures must be monitored closely for the first 3 weeks after cast application. This is most easily handled in a cooperative patient by cast wedging. Some children require application of a second cast under general anesthesia 2 to 3 weeks after injury, particularly if the subsidence of swelling has caused the cast to loosen. Surgical indications include the presence of soft-tissue injuries, unstable fracture patterns, fractures associated with compartment syndrome, and the child with multiple injuries. Surgical options in children include percutaneous pins, external fixation, plates and screws, and intramedullary nails.
REFERENCES: Heinrich SD: Fractures of the shaft of the tibia and fibula, in Rockwood CA, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 1340-1346.
Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 583-595.

Question 6

In addition to the radiographic features seen in Figures 49a and 49b, this patient will most likely have which of the following findings?

Explanation

DISCUSSION: The radiographs show the characteristic features of osteopetrosis. The condition results from defective resorption of immature bone by osteoclasts. There are three distinct clinical forms: (1) infantile-malignant, which is autosomal recessive and fatal in the first few years of life if untreated; (2) intermediate autosomal recessive; and (3) autosomal dominant. These conditions do not follow a malignant course, and patients have normal life expectancy with orthopaedic problems and anemia. In the malignant form, the clinical features include frequent fractures, macrocephaly, progressive deafness and blindness, hepatosplenomegaly, and severe anemia beginning in early infancy or in utero. Deafness and blindness are generally thought to represent effects of pressure on nerves and usually occur later in life. The anemia is caused by encroachment of bone on marrow, resulting in obliteration, and the hepatosplenomegaly is caused by compensatory extramedullary hematopoiesis. Dental caries and abscesses, as well as osteomyelitis of the mandible, are also seen. Most patients have normal intelligence. Treatment of the malignant form includes high dose 1,25 dihydroxy vitamin D with a low-calcium diet to stimulate bone resorption, not because there are vitamin deficiencies. Bone marrow transplant has also been successful.
REFERENCES: Herring JA: Tachdjian’s Pediatric Orthopedics, ed 4. Philadelphia, PA, WB Saunders, 2002, p 1550.
Zaleske DJ: Metabolic and endocrine abnormalities, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 212-214.
Kaplan FS, August CS, Fallon MD, et al: Successful treatment of infantile malignant osteopetrosis by bone-marrow transplantation: A case report. J Bone Joint Surg Am 1988;70:617-623.

Question 7

Failure of posterolateral corner repair or reconstruction of the knee may be associated with which of the following? Review Topic

Explanation

Failure to reconstruct a torn anterior cruciate ligament or posterior cruciate ligament at the time of posterolateral corner (PLC) repair or reconstruction dramatically increases the likelihood of PLC failure. Uncorrected varus malalignment places extensive tension on a PLC reconstruction and is a well recognized cause of failure. Valgus malalignment and medial collateral ligament reconstruction are not recognized means of failure.

Question 8

An 18-year-old football player has intense pain and is unable to bear weight on the right knee after being tackled from the front. A posterior knee dislocation is reduced on the field. Because the game took place in a remote location, the patient is not examined in the emergency department until 5 hours after the injury. Examination now shows a grossly swollen knee with moderate ischemia in the lower leg. Posterior tibial and dorsalis pedis pulses are diminished. The best course of action should be to

Explanation

DISCUSSION: Vascular injuries occur in approximately 20% to 35% of knee dislocations, of which one third are posterior. Recognition of the vascular injury is essential. Normal pulses or normal capillary refill do not preclude an arterial injury, and arteriography should be considered in all knee dislocations. If the leg is ischemic, the arteriogram should be circumvented and the patient taken directly to the operating room. The risk of muscle fibrosis, contracture, or vascular insufficiency, and the need for amputation increase significantly when ischemia exceeds 6 hours. This patient has ischemia and is considered a vascular emergency. As such, delays for a thorough examination of the ligament, MRI scans, and even an arteriogram are unwarranted. Concurrent ligamentous repair and reconstruction should be deferred until vascular stability has been achieved.
REFERENCES: Kremchek TE, Welling RE, Kremchek EJ: Traumatic dislocation of the knee. Orthop Rev 1989;18:1051-1057.
Reckling FW, Peltier LF: Acute knee dislocations and their complications. J Trauma 1969;9:181-191.

Question 9

98 degrees (range, 0 degrees to 9 degrees). In knees with varus joint lines

Explanation

Question 10

-Which gene mutation is associated with the condition shown in Figures a and b?

Explanation

Question 11

A 32-year-old has diffuse pain, weakness, and limited overhead motion in the shoulder as a result of falling on his outstretched arm 2 months ago. Examination reveals medial scapular winging, and an electromyogram shows denervation of the long thoracic nerve. Management should consist of

Explanation

Most cases of isolated serratus anterior palsy resolve spontaneously, usually within 6 to 9 months after traumatic injury and within 2 years after an infectious cause. Pectoralis major-fascia lata graft is an effective treatment for persistent winging.

Question 12

Figure 1 is the radiograph of a 21-year-old college lacrosse player who has a 2-year history of progressive left groin pain that is exacerbated by activity. Pain is preventing him from participating with his team. Examination reveals a fit man without tenderness to palpation around the hip. No clicking or popping occurs with hip range of motion. Strength of all muscles about the hip is normal, but there is some mild pain with resisted hip flexion and hip adduction. While lying supine, progressive hip flexion with internal rotation and adduction reproduces his groin pain. The patient participates in physical therapy for 8 weeks with his team's trainer but notes little improvement. What is the most appropriate next diagnostic step to determine the cause of his pain?

Explanation

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly
used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has important functions for hip stability and maintenance of the suction seal of the joint.

Question 13

Which of the following infectious organisms may be associated with underlying malignancy?

Explanation

DISCUSSION: Evidence implicates an association, albeit unexplained, between Clostridium septicum infection and malignancy, particularly hematologic or intestinal malignancy. The malignancy is often at an advanced stage, compromising survival of the patients. A bowel portal of entry is postulated for most patients. In the absence of an external source in the patient with clostridial myonecrosis or sepsis, the cecum or distal ileum should be considered a likely site of infection. Increased awareness of this association between Clostridium septicum and malignancy, and aggressive surgical treatment, may result in improvement in the present 50% to 70% mortality rate. Other organisms associated with malignancy include group Clostridium streptococci that are occasionally associated with upper gastrointestinal malignancies.
REFERENCES: Schaaf RE, Jacobs N, Kelvin FM, et al: Clostridium septicum infection associated with colonic carcinoma and hematologic abnormality. Radiology 1980;137:625-627.
Katlic MR, Derkac WM, Coleman WS: Clostridium septicum infection and malignancy. Ann Surg 1981;193:361-364.

Question 14

What is the effect on knee kinematics following placement of an anterior cruciate ligament (ACL) graft at the 12 o’clock position?

Explanation

DISCUSSION: Endoscopic ACL reconstructive techniques may result in a vertical graft placement. The reconstructed ligament will resist anterior translation of the tibia but the graft will not restore rotatory stability. Decreased flexion and extension are caused by placement of the femoral tunnel too anterior and posterior, respectively. Impingement of the graft on the femoral notch is caused by anterior placement of the tibial tunnel or inadequate notchplasty.
REFERENCES: Scopp JM, Jasper LE, Belkoff SM, et al: The effect of oblique femoral tunnel placement on rotational constraint of the knee reconstructed using patellar tendon autografts. Arthroscopy 2004;20:294-299.
Carson EW, Simonian PT, Wickiewicz TL, et al: Revision anterior cruciate ligament reconstruction. Instr Course Lect 1998;47:361-368.

Question 15

A patient has a displaced midshaft transverse fracture of the humerus and is neurologically intact. Following closed reduction and application of a coaptation splint, the patient cannot dorsiflex the wrist or the fingers at the metacarpophalangeal joints of the hand. What is the next most appropriate step in management?

Explanation

DISCUSSION: The answer to this question is controversial. All of the standard textbooks state that development of a radial nerve palsy during initial fracture management may represent a laceration or injury of the nerve by bone fragments at the time of manipulation; therefore, surgery should be considered. However, it appears that there is no scientific basis for this decision. A review of the available literature shows that the results were the same for patients who were observed as for those who underwent radial nerve exploration. The indications for surgical exploration include palsies associated with open fractures, irreducible closed fractures, and vascular injuries. The only other relative indication for surgical exploration is following manipulation of a Holstein-Lewis fracture (a distal third fracture of the humerus with a lateral spike). In this type of fracture, exploration may be necessary if a closed reduction leads to radial nerve palsy because the spike may lacerate or compress the nerve. Observation for return of nerve function may be appropriate for 3 months or longer prior to considering late exploration.
REFERENCES: Bostman O, Bakalim G, Vainionpaa S, Wilppula E, Patiala H, Rokkanen P: Radial palsy in shaft fracture of the humerus. Acta Orthop Scand 1986;57:316-319.
Shaz JJ, Bhatti NA: Radial nerve paralysis associated with the fractures of the humerus: A review of 62 cases. Clin Orthop 1983;172:171-176.
Holstein A, Lewis GB: Fractures of the humerus with radial nerve paralysis. J Bone Joint Surg Am 1963;458:1382-1388.

Question 16

A 42-year-old woman has a history of nontraumatic ankle swelling with tenderness over the Achilles tendon and plantar fascia. She reports that while vacationing in Connecticut 2 months ago she noted the presence of a “red bull’s eye” rash. Management should consist of

Explanation

DISCUSSION: The most likely diagnosis is Lyme disease because of the patient’s recent vacation in an area with a high risk of exposure. The most effective treatment is doxycycline.
REFERENCES: Neu HC: A perspective on therapy of Lyme infection. Ann NY Acad Sci 1988;539:314-316.
Faller J, Thompson F, Hamilton W: Foot and ankle disorders resulting from Lyme disease. Foot Ankle 1991;11:236-238.

Question 17

A 13-year-old pitcher is hit in the left intercostal space by a line drive ball. He collapses, is apneic and unresponsive, and his radial pulse is absent. What is the next step in management? Review Topic

Explanation

Sudden death in athletes without structural cardiac damage is referred to as commotio cordis. This is an emergency. The immediate priorities are protection of the airway, starting CPR, and early cardioversion as this patient has an arrhythmia. It is hypothesized to occur from apnea, vasovagal reflex, or ventricular arrhythemia as reported by Maron and associates from the direct impact of the baseball during a vulnerable part of the cardiac rhythm. Janda and associates reported that soft-core baseballs may not differ from standard baseballs with regard to the risk of fatal chest-impact injury while playing baseball. High survival rates are associated with rapid treatment.

Question 18

Nonsurgical management of pectoralis major tears is likely to result in weakness of glenohumeral Review Topic

Explanation

Nonsurgical management is considered for proximal tears as well as partial tears in some individuals. Surgical management is often not appropriate in older or sedentary patients. However, patients treated nonsurgically will have a significant cosmetic defect, as well as weakness in adduction and internal rotation.

Question 19

During preparation for the NCAA wrestling championships, a participant reports the development of vesicular lesions on his right chest wall that are mildly painful; however, they have not affected his ability to wrestle. How should this athlete be managed? Review Topic

Explanation

Herpes simplex virus (HSV) can cause serious outbreaks on athletic teams, especially wrestling. HSV is highly contagious; it is secreted from active blisters, saliva, and mucous membranes. For wrestlers, the NCAA states that the athlete must be free from systemic symptoms and any new blisters for 72 hours before being allowed to participate. Also, all lesions must be dry and crusted and at least 120 hours of antiviral therapy should have been instituted.

Question 20

50%

Explanation

By 5 years, the allograft cartilage will be completely acellular, so there will be no residual donor chondrocytes.
Enneking et al. conducted both radiographic and histologic studies of sixteen massive retrieved human allografts four to sixty-five months after implantation. Analysis of the articular cartilage revealed no evidence that any chondrocytes had survived, even when the graft had been cryoprotected before it was preserved by freezing.
A 64-year-old woman with a longstanding history of rheumatoid arthritis complains of finger dysfunction for the past 6 months. Figure A displays her hand during active extension of all fingers. Figure B displays her hand maintaining her fingers extended following passive extension. What is the next most appropriate treatment for the ring finger?
Spiral oblique retinacular ligament reconstruction
Sagittal band reconstruction
Lateral band reconstruction
Central slip reconstruction
Triangular ligament and transverse retinacular ligament reconstruction
Sagittal band disruption is often associated with rheumatoid arthritis. When this patient attempts to actively extend the affected digit, the extensor tendon
subluxates ulnarly as a result of the sagittal band rupture, and is left with an extensor lag. If one passively extends the finger fully, the patient is able to maintain this position, as the tendon is intact.
Sagittal band reconstruction can be performed with Watson's technique of creating a distally based tendon graft harvested from the central third of the extensor tendon, passed deep to the intermetacarpal ligament and sutured back to itself. Illustration A depicts an intraoperative view of the tendon before reconstruction and Illustration B displays tendon following sagittal band reconstruction. Illustration C displays all of the anatomic locations
of the options listed above.
A splenectomy is performed in a 7-year-old boy following a motor vehicle accident. All of the following are recommended for long-term management EXCEPT:
Pneumococcal vaccination
Haemophilus influenza type B vaccination
Meningococcal group C vaccination
Lifelong prophylactic antibiotics
Hepatitis A vaccination
All of the responses are correct except the need for Hepatitis A vaccine. Hepatitis A is a virus with tropism for hepatocytes which causes infection from fecal-oral contaminated food/water, and shows no increased rate of either infectivity or morbidity in patients with hyposplenism.
Basic recommendations for splenectomized patients include:
All splenectomized patients and those with functional hyposplenism should receive pneumococcal immunization.
Patients not previously immunized should receive haemophilus influenza type B vaccine.
Patients not previously immunized should receive meningococcal group C conjugate vaccine.
Influenza immunization should be given.
Lifelong prophylactic antibiotics are still recommended (oral phenoxymethylpenicillin or erythromycin). This is seemingly despite lack of good data demonstrating a role for lifelong chemoprophylaxis and the acknowledgement that long-term compliance may be problematic.
Davies et al review the current level of evidence supporting these guidelines
for infection prevention in patients with hyposplenism. New to these guidelines are issues regarding occupational exposure and the use of the meningococcal group C and the seven-valent pneumococcal vaccine in non-immunized hyposplenic patients.
Gandhi et al evaluated their nonoperative management of blunt splenic injury in pediatric trauma care. They found compared to historical controls, children with blunt splenic injuries who were hemodynamically stable could be safely monitored with a protocol which required 4 days of inpatient care, 3 weeks of quiet home activities, and 3 months of light activity. This protocol seems to allow for safe return to unrestricted activity.
Incorrect Answer:
Ligaments attach to bone by both direct insertion and indirect insertion. Which of the following most accurately describes the order of the four transition zones of direct insertion?
Ligament > fibrocartilage > mineralized fibrocartilage > bone
Ligament > mineralized fibrocartilage > fibrocartilage > bone
Ligament > mineralized fibrocartilage > periosteum > bone
Ligament > Sharpey's fiber > periosteum > bone
Ligament > periosteum > fibrocartilage > bone
There are two types of tendon/ligament insertion into bone: direct and indirect insertion. The more common, indirect insertion, occurs when the superficial ligament fibers insert into the periosteum. Direct insertion of tendon/ligaments
into bone occurs through a transition of 4 distinct phases: 1) ligament, 2) fibrocartilage, 3) mineralized fibrocartilage, and 4) bone.
While flexing the elbow to perform a biceps curl, what type of muscle contraction is occuring?
Isometric
Isokinetic
Plyometric
Eccentric
Concentric
Concentric muscle contractions occur when a muscle shortens during contraction, as in the upward motion when performing a biceps curl. An eccentric contraction occurs when a muscle lengthens with contraction, as in the "negative" or lowering motion of a biceps curl. An example of an isometric (muscle contracts while maintaining constant length) contraction would be pushing against an immovable object. An example of an isokinetic (muscle has constant speed of contraction) occurs with specialized equipment like Cybex machines. Plyometric contractions occur when a muscle rapidly lengthens just prior to contraction - like during repetitive box jumping.
Woo and Buckwalter describe the mechanisms, barriers, and molecular processes involved in ligament and tendon injury and repair.
A 34-year-old laborer has her left foot crushed in a piece of farming equipment as shown in Figure A. All of the following are reasons for a poor outcome following a crush injury to the foot EXCEPT:
Workers compensation injury
Development of reflex sympathetic dystrophy (complex regional pain syndrome)
Delayed soft-tissue coverage in mangled extremities
Immediate skeletal stabilization
Ongoing litigation
This patient has a mangled extremity. Rigid skeletal stabilization is recommended to enhance soft-tissue healing.
Level 4 evidence from Myerson et al found that delayed soft-tissue coverage in mangled extremities correlated with poor outcome. Poor results also occurred
if treatment was not immediately initiated (immediate debridement shown in Illustration A), if patients subsequently had neuritis or reflex sympathetic dystrophy, or if patients were involved in ongoing workers' compensation and litigation. Neuroischemia following substantial soft-tissue injury likely plays a role in the development of chronic pain after crush injuries to the foot, either through direct trauma to the peripheral nerves or by intraneural or extraneural fibrosis. This trauma to the nerve may cause chronic neuritis, which then triggers a sympathetically mediated reflex sympathetic dystrophy (complex regional pain syndrome).
A 65-year-old man undergoes total knee replacement and is found to have deep vein thrombosis two days later. What molecule is
thought to be involved in this process when it is released during surgical dissection?
Prothrombin
RANKL
IL-1b
Thromboplastin
Factor XI Corrent answer: 4
Thromboplastin is also known more commonly as Tissue Factor (TF), which is involved in the Extrinsic Pathology of the coagulation cascade.
During surgical dissection, insults occur to the endothelial walls of blood vessels. There are three ways in which the body reacts to form a clot so that the patient does not bleed excessively. One is via vessel contraction, another is by collagen release, and a third is by tissue thromboplastin release. Thromboplastin release is part of the extrinsic coagulation pathway (see
Illustration A). Thromboplastin release activates Factor VII which activates Factor X which converts prothrombin to thrombin. Thrombin is the catalyst for converting fibrinogen to fibrin which induces clot formation. While this is useful for decreasing bleeding, it is the same mechanism by which a deep venous thrombosis (DVT) develops.
Which of the following materials has a Young's modulus of elasticity that is most similar to cortical bone
Titanium
Zirconia
Stainless steel
Ceramic (Al2O3)
Alloy (Co-Cr-Mo)
Of the materials listed Titanium has an elastic moduli closest to cortical bone. Titanium is extra-ordinarily light, strong, highly ductile, and corrosion resistant. Titanium is however very notch sensitive and has poor wear resistance.
Young Modulus of Elasticity is defined as the stiffness (ability to maintain
shape under external loading) of a material. On the stress vs. strain curve it is defined as the slope of the line in the elastic zone (see Illustration A). Young’s modulus is constant and different for each material. The relevant moduli (unit GPa) are approximated below:

Question 21

A patient undergoes hip arthroscopy, and the pathology is seen in Figure 18. What is the most likely diagnosis?

Explanation

DISCUSSION: The motorized shaver is adjacent to the acetabular labrum, which is torn. The femoral head and acetabulum are normal in appearance. Neither the fat pad nor a loose body is identified.
REFERENCE: Byrd JWT: Operative Hip Arthroscopy. New York, NY, Thieme Medical Publishers, 1998, pp 93-104.

Question 22

A 20-year-old minor league baseball pitcher is diagnosed with a symptomatic torn ulnar collateral ligament (UCL) in his pitching elbow. Nonsurgical management consisting of rest and physical therapy aimed at elbow strengthening has

Explanation

High-level pitchers with symptomatic UCL tears require reconstruction, with autograft being the best studied graft selection. With concomitant ulnar nerve symptoms, a simultaneous ulnar nerve transposition provides good results. Ligament “repairs” and allograft reconstructions have not shown good long-term results.

Question 23

A 19-year-old man has had pain and swelling in his left forearm for the past 8 months. Laboratory studies show a mildly elevated WBC count and erythrocyte sedimentation rate. Radiographs are shown in Figures 58a and 58b, a CT scan is shown in Figure 58c, and T 1 - and T 2 -weighted MRI scans are shown in Figures 58d and 58e, respectively. A biopsy specimen is shown in Figure 58f. Immunohistochemistry demonstrates that the lesion is negative for leukocyte common antigen (CD34). What is the most common cytogenetic translocation associated with this lesion?

Explanation

DISCUSSION: The imaging studies show a permeative lytic destructive lesion in the proximal radius with “hair-on-end” periosteal reaction and a large soft-tissue mass most consistent with Ewing’s sarcoma. The pathology reveals monotonous sheets of “round blue” cells. This limits the differential diagnosis to primary lymphoma of bone versus Ewing’s sarcoma. These are best differentiated by immunohistochemistry, cytogenetics, and flow cytometry. Lymphoma of bone is typically CD34 positive and CD99 negative; whereas, the reverse is true of Ewing’s sarcoma, CD34 negative and CD99 positive. The most common cytogenetic translocation with Ewing’s sarcoma is 11; 22; 21; 22 and 7; 22 translocations have also been reported in Ewing’s sarcomas. The X; 18 translocation is most commonly associated with synovial cell sarcomas; the 12; 22 translocation is most commonly associated with clear cell sarcomas; the 2; 13 translocation is most commonly associated with alveolar rhabdomyosarcomas, and the 12; 16 translocation is most commonly associated with myxoid liposarcomas. Flow cytometry is used to characterize the cell types of lymphomas.
REFERENCES: Womer R: The cellular biology of bone tumors. Clin Orthop Relat Res 1991;262:12-21.
Yamaguchi U, Hasegawa T, Morimoto Y, et al: A practical approach to the clinical diagnosis of Ewing’s sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue. J Clin Pathol 2005;58:1051-1056.
Lazar A, Abruzzo LV, Pollock RE, et al: Molecular diagnosis of sarcomas: Chromosomal translocations in sarcomas. Arch Path Lab Med 2006;130:1199-1207.

Question 24

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

Explanation

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

Question 25

A 22-year-old college baseball pitcher reports the recent onset of anterior and posterosuperior shoulder pain in his throwing shoulder. Examination shows a 15-degree loss of internal rotation, tenderness over the coracoid, and a positive relocation test. Radiographs are normal, and an MRI scan without contrast shows no definitive lesions. A rehabilitation program is prescribed. Which of the following regimens should be initially employed? Review Topic

Explanation

Throwing athletes, particularly pitchers, have a high incidence of shoulder pain. Recent evidence suggests that posteroinferior capsular tightness and scapular dyskinesis may play a substantial role in the pathologic cascade, culminating in the development of articular surface rotator cuff tears and tearing of the posterosuperior labrum. These patients have posterosuperior shoulder pain primarily. Furthermore, these athletes are susceptible to a muscular fatigue syndrome, the SICK (Scapular malposition, Inferior medial border prominence, Coracoid pain and malposition, and dysKinesis of scapular movement) scapula syndrome. This patient has an internal rotation deficit and tenderness over the coracoid. The internal rotation deficit is addressed by stretching the posterior capsule. The tenderness over the coracoid has been attributed to a contracture of the pectoralis minor tendon secondary to scapular malposition. The initial phase of the rehabilitation regimen is directed at stretching the posterior capsule and pectoralis minor tendon.

Question 26

A 58-year-old man with a 50-year history of osteomyelitis of the left tibia has a painful ulceration of the anterior lower limb. Figure 1 is the clinical photograph of the wound, which had purulent discharge and an unpleasant odor. Figures 2 and 3 are radiographs of the left tibia. A biopsy reveals malignant degeneration. What are the most likely findings?

Explanation

Discussion: Squamous cell carcinoma is the most common type of malignant tumor deriving from chronic osteomyelitis. The most frequently affected site is the tibia, followed by the femur. When the neoplasm invades the bone, there is either osteolytic erosion or a pathological fracture. Diagnosis is confirmed by biopsy at all suspicious wound sites. The malignant transformation most often results in squamous cell carcinoma and much more rarely in fibrosarcoma, osteosarcoma, reticulosarcoma, malignant fibrous histiocytoma or angiosarcoma. Many experts accept amputation as the best treatment option for carcinomatous transformation of chronic bone infections.

Question 27

Which of the following conditions is most commonly associated with the congenital hand problem shown in Figure 33?

Explanation

The condition shown in the figure is congenital constriction band syndrome. The probable causes of the syndrome are hemorrhages and necrosis in mesenchymal tissues caused by exogenous agents after the condensation of the digital rays. Patients have been grouped by Patterson in the following clinical types; simple ring constrictions, ring constrictions accompanied by fusion of the distal parts with or without lymphedema, ring constrictions accompanied by fusion of the distal parts ranging from fenestrated or terminal syndactyly, and intrauterine amputation. Congenital constriction band syndrome is an uncommon disorder that can present with many clinical features including constriction bands, intrauterine amputations, syndactyly, acrosyndactyly, caraniofacial defects such as cleft lip and palate, visceral anomalies from truncal bands, and fetal death. Clubfoot is a frequently associated anomaly.

Question 28

The radiographic feature seen in Figure 37 that best indicates a slow-growing process is the

Explanation

DISCUSSION: For the fibula (or any bone) to bow, a long-standing process needs to be present. Pressure from a rapid process would cause erosion, not allowing the bone to remodel. The other features are helpful confirmatory findings but also may be associated with aggressive processes. In this patient, the fibular deformity is caused by a sessile osteochondroma of the tibia.
REFERENCES: Lodwick GS, Wilson AJ, Farrell C, Virtama P, Dittrich F: Determining growth rates of focal lesions of bone from radiographs. Radiology 1980;134:577-583.
Moser RP Jr, Madewell JE: An approach to primary bone tumors. Radiol Clin North Am 1987;25:1049-1093.

Question 29

A 43-year-old woman has a 2-week history of right shoulder pain. She denies any injury to initiate her symptoms but states that she has shoulder pain with range of motion and lifting objects. Examination reveals mild pain with abduction, empty can testing, and with the Neer and Hawkins impingement tests. Her range of motion with the right shoulder reveals passive forward flexion to 90 degrees, abduction to 90 degrees, external rotation at the side to 15 degrees, and internal rotation to her buttock. The uninvolved left shoulder has forward flexion to 160 degrees, abduction to 150 degrees, external rotation at the side to 60 degrees, and internal rotation to T6. Radiographs of the shoulder are normal. What is the next most appropriate step in management? Review Topic

Explanation

The patient has the recent onset of adhesive capsulitis, which is characterized by loss of both active and passive range of motion. A home exercise program is as helpful as organized therapy to improve her range of motion. While a sling might be appropriate for comfort, continuous use might increase her shoulder stiffness. Surgical treatments, such as a manipulation under anesthesia or arthroscopic capsular release, might be necessary if her motion cannot be restored with physical therapy and home exercises. However, the natural history of idiopathic adhesive capsulitis is self limited and does not usually require surgery. An arthroscopic rotator cuff repair is not indicated because she does not have a rotator cuff tear.

Question 30

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

Explanation

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

Question 31

What mechanism is associated with the spontaneous resorption of herniated nucleus pulposus?

Explanation

DISCUSSION: Nonsurgical modalities remain the mainstay for treatment of herniated disks. Spontaneous resorption of herniated disks frequently is detected by MRI. Marked infiltration by macrophages and neovascularization are observed on histologic examination of herniated disks, and the resorption is believed to be related to this process. Many cytokines such as vascular endothelial growth factor, tumor necrosis factor-alpha, and metalloproteinases have been implicated in this process, but none has been found to be singularly responsible.
REFERENCES: Haro H, Kato T, Kamori H, et al: Vascular endothelial growth factor (VEGF)-induced angiogenesis in herniated disc resorption. J Orthop Res 2002;20:409-415.
Doita M, Kanatani T, Ozaki T, et al: Influence of macrophage infiltration of herniated disc tissue on the production of matrix metalloproteinases leading to disc resorption. Spine

2001;26:1522-1527.

Question 32

Which of the following drawbacks is associated with the Ganz periacetabular osteotomy?

Explanation

DISCUSSION: Although technically challenging, the Ganz periacetabular osteotomy offers advantages over other rotational pelvic osteotomies. Posterior column integrity is maintained, as is the acetabular vascular supply. Free mobility of the fragment makes large corrections in the center edge angle possible. Because of the asymmetric cuts and the need to restore anterior coverage, there is a tendency to anterior displacement of the joint while flexing the acetabulum. The procedure is commonly performed through a Smith-Petersen incision.
REFERENCES: Trousdale RT, Ganz R: Periacetabular osteotomy, in Callaghan JJ, Rosenberg AG, Rubash HE (eds): The Adult Hip. Philadelphia, Pa, Lippincott-Raven, 1998, pp 789-802.
Ganz R, Klaue K, Vinh TS, Mast JW: A new periacetabular osteotomy for the treatment of hip dysplasias: Technique and preliminary results. Clin Orthop 1988;232:26-36.
MacDonald SJ, Hersche O, Ganz R: Periacetabular osteotomy in the treatment of neurogenic acetabular dysplasia. J Bone Joint Surg Br 1999;81:975-978.

Question 33

Which of the following is most important to acheive a good outcome following a Syme amputation?

Explanation

DISCUSSION: A Syme amputation is effectively a tibiotalar disarticulation, which provides an end-bearing stump that could potentially allow ambulation without a prosthesis over short distances. It works better for tumor and trauma, but the heel pad must be viable. The two most common problems are 1) skin sloughing from compromised vascular supply and 2) migration of the heel pad due to instability. A hypermobile heel pad can cause difficulty with prosthesis wear and damage to the soft tissues which can eventually lead to failure. Both malleoli are usually removed in the procedure, except in children or during the first stage procedure of a diabetic or infection case. The tibialis anterior is usually tenodesed to the anterior heel pad along with the EDL tendon to avoid posterior migration of the heel pad.

Question 34

A displaced pediatric supracondylar humerus fracture is treated with closed manipulation and placement of 2 Kirschner wires placed from the lateral side. What would be the effect of adding a third pin from the lateral side? Review Topic

Explanation

Multiple biomechanical studies have shown that the addition of a third pin from the lateral side improves construct stiffness in the presence of medial column loss or slight internal rotation of the distal fragment. The same studies show that addition of a medial pin (cross pinning) has essentially the same benefit. Placement of a medial pin increases risk for iatrogenic nerve injury.

Question 35

A 17-year-old high school football player is seen for follow-up after sustaining an injury 3 days ago. He reports that he tackled a player, felt numbness throughout his body, and could not move for approximately 15 seconds. A spinal cord injury protocol was initiated on the field. Evaluation in the emergency department revealed a normal neurologic examination and full painless neck motion. He states that he has no history of a similar injury. An MRI scan of the cervical spine is normal. During counseling, the patient and his family should be informed that he has sustained

Explanation

DISCUSSION: The long-term effect of transient quadriplegia is unknown. Based on a history of one brief episode of transient quadriplegia and normal examination and MRI findings, the risk of permanent spinal cord injury with a return to play is low. There is a risk of recurrent episodes of transient quadriplegia after the initial episode.
REFERENCES: Morganti C, Sweeney CA, Albanese SA, et al: Return to play after cervical spine injury. Spine 2001;26:1131-1136.
Odor JM, Watkins RG, Dillin WH, et al: Incidence of cervical spinal stenosis in professional and rookie football players. Am J Sports Med 1990;18:507-509.
Torg JS, Naranja RJ Jr, Palov H, et al: The relationship of developmental narrowing of the cervical spinal canal to reversible and irreversible injury of the cervical spinal cord in football players. J Bone Joint Surg Am 1996;78:1308-1314.
Vaccaro AR, Watkins B, Albert TJ, et al: Cervical spine injuries in athletes: Current return-to-play criteria. Orthopedics 2001;24:699-703.

Question 36

A 77-year-old man who underwent right total knee replacement surgery 2 and a half years ago has had knee pain since surgery. The pain is diffuse, constant, and made worse with activity. He notes warmth and swelling in his knee. Examination shows a well-healed incision, no erythema, moderate warmth, synovitis, and an effusion. The knee is stable, and has an arc of flexion between 3° and 120°. Radiographs show well-fixed and well-aligned implants. What is the most appropriate initial treatment?

Explanation

DISCUSSION:
This patient's history and physical findings are concerning for deep infection. Inflammatory markers, including ESR and CRP, should be obtained first. If the levels are elevated, knee aspiration should be performed for the synovial cell count and culture. A bone scan is not indicated in an initial investigation for deep infection; it is rarely helpful and is not cost effective. CT to assess implant rotation is an appropriate investigation for knee pain when the clinical scenario is not suspicious for a deep infection and when infection has been excluded.

Question 37

A 23-year-old man reports a 6-year history of recurrent instability in the right dominant shoulder. He has not undergone surgery and has essentially stopped all of his sporting activities. On examination, he has instability and apprehension in the midrange of motion (abduction of 45 to 60 degrees with external rotation) and a palpable clunk representing a transient dislocation over the anterior glenoid rim. A three-dimensional CT scan is shown in Figure 31. What is the most appropriate surgical intervention to provide him with reliable stability postoperatively?

Explanation

DISCUSSION: In the setting of significant anteroinferior glenoid bone deficiency (greater than 20% to 25%), both open and arthroscopic Bankart repairs have demonstrated higher rates of failure. Bony glenoid augmentation procedures such as the Bristow-Lataijet, which describe coracoid transfers to reconstruct the deficient glenoid, have led to decreased rates of recurrent shoulder instability. In this scenario, the patient has a significant loss of glenoid bone. There are also several clues in the history to suspect bone deficiency: multiple recurrences, a long history of recurrence, and instability in the midranges of motion.
A bony augmentation procedure such as the Lataijet has been well-described to provide a well functioning and stable shoulder joint. A hemiarthroplasty is not indicated in the absence of arthritis. Subscapularis
advancement will not address the bone loss.
REFERENCES: Hovelius L, Sandstrom B, Sundgren K, et al: One hundred eighteen Bristow-Latarjet repairs for recurrent anterior dislocation of the shoulder prospectively followed for fifteen years: Study I— clinical results. J Shoulder Elbow Surg 2004;13:509-516.
Schroder DT, Provencher MT, Mologne TS, et al: The modified Bristow procedure for anterior shoulder instability: 26-year outcomes in Naval Academy midshipmen. Am J Sports Med 2006;34:778-786.
Itoi E, Lee SB, Berglund LJ, et al: The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: A cadaveric study. J Bone Joint Surg Am 2000;82:35-46.

Question 38

A 7-year-old boy has had low back pain for the past 3 weeks. Radiographs reveal apparent disk space narrowing at L4-5. The patient is afebrile. Laboratory studies show a WBC count of 9,000/mm P 3 P and a C-reactive protein level of 10 mg/L. A lumbar MRI scan confirms the loss of disk height at L4-5 and reveals a small perivertebral abscess at that level. To achieve the most rapid improvement and to lessen the chances of recurrence, management should consist of

Explanation

DISCUSSION: The patient has diskitis. Administration of IV antibiotics speeds resolution and minimizes recurrence. Bed rest and cast immobilization have been successfully used to treat this disorder but can be associated with prolonged recovery and frequent recurrence, even when oral antibiotics are administered. A perivertebral abscess seen in association with this condition usually resolves without surgery.
REFERENCES: Ring D, Johnston CE II, Wenger DR: Pyogenic infectious spondylitis in children: The convergence of discitis and vertebral osteomyelitis. J Pediatr Orthop

1995;15:652-660.
Crawford AH, Kucharzyk DW, Ruda R, et al: Diskitis in children. Clin Orthop 1991;266:70-79.

Question 39

A 30-year-old man has had severe knee pain and swelling for 1 week. He reports he previously had acromioclavicular joint pain that disappeared. He denies any fever. Aspiration of a cloudy fluid from the knee reveals a WBC count of greater than 50,000 with 90% polymorphonucleocytes. While awaiting culture results, what is the most appropriate action?

Explanation

The patient has polyarticular gonococcal arthritis. Acute septic arthritis in adults can be separated into two major patient groups: young (age 15 to 40 years) healthy, sexually active patients with gonococcal pyogenic arthritis and elderly or immunocompromised patients with nongonococcal septic arthritis. In gonococcal septic arthritis, the infecting organism is Neisseria gonorrhea. It is the most common cause of acute joint infection in persons 15 to 40 years of age in the U.S. The clinical presentation is variable, but typically includes migratory polyarthralgias, fever, rash, urethral or vaginal discharge, and tenosynovitis. A patient with disseminated gonococcal infection may report few genital symptoms. More than 50% of these infections are polyarticular. Because patients with gonococcal septic arthritis are healthy, prompt antibiotic treatment results in a generally good prognosis. MRSA septic arthritis would be associated with fever, more rapid onset of symptoms, and is rarely polyarticular.

Question 40

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

Explanation

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

Question 41

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 42

A 35-year-old runner has pain beneath the second metatarsophalangeal joint. He reports that he has significantly decreased his running distance since the onset of the pain. He denies any history of trauma or injury to the foot. A radiograph is shown in Figure 14. Initial management should consist of

Explanation

DISCUSSION: The presence of the relatively long second metatarsal, along with the close approximation of the second and third metatarsal heads, are consistent with second metatarsophalangeal tenosynovitis. The hallmark of initial management is conservative. Modalities include taping, nonsteroidal anti-inflammatory drugs, metatarsal pads, and cortisone injections. Trepman and Yeo combined the use of a cortisone injection with a rocker bottom sole. Mizel and Michelson reported their results using an extended rigid steel shank shoe along with a cortisone injection.
REFERENCES: Trepman E, Yeo SJ: Nonoperative treatment of metatarsophalangeal joint synovitis. Foot Ankle Int 1995;16:771-777.
Mizel MS, Michelson JD: Nonsurgical treatment of monarticular nontraumatic synovitis of the second metatarsophalangeal joint. Foot Ankle Int 1997;18:424-426.

Question 43

A form of renal osteodystrophy that is characterized by pure osteomalacia is caused by

Explanation

There are many causes of rickets and osteomalacia. Renal osteodystrophy is a common complication of chronic renal failure and is one of the most common causes of osteomalacia. Pure osteomalacia is caused by the aluminum in phosphate binders used to treat hyperphosphatemia in renal failure. Desferoxamine is an effective chelator of aluminum in patients with biopsy documented aluminum-associated osteomalacia. Pure osteomalacia also can be caused by hypophosphatemia. The other choices are part of the mechanism of bone changes in renal osteodystrophy.

Question 44

A 32-year-old female sustained the injury seen in Figure A after a motor vehicle accident. On physical exam there was obvious deformity about the arm with a laceration that probed to bone over the lateral aspect of the arm. The patient was neurovascularly intact. She was treated with an intramedullary nail. Which of the following is true?

Explanation

When compared to compression plating, anterograde intramedullary nailing results show increased risk for shoulder impingement.
Options for operative management of humeral shaft fractures mainly consist of intramedullary nail or plate and screw constructs. The main advantage to intramedullary nailing is when the soft tissue envelope makes a large incision undesireable or the fracture pattern dictates a relative stability construct - such as segmental or massively comminuted injuries. The disadvantages include trauma to the rotator cuff, post operative shoulder pain, indirect reduction leading to increased risk of malrotation, and increased reoperation for implant removal.
Li et al. performed a randomized controlled trial with 45 patients that investigated the difference in post operative malrotation and functional outcomes when comparing intramedullary nails versus open reduction and internal fixation. They concluded that
when comparing the two operative options, patients who underwent intramedullary nailing had a greater degree of malrotation, which was associated with decreased range of motion. Additionally, they found lower functional scores with patients who underwent intramedullary nailing.
Kurup et al. performed a systematic review comparing outcomes between compression plating and intrameduallary nailing for operative treatment of humeral shaft fractures. With a total of 260 patients, they found no difference with blood loss, fracture union, iatrogenic radial nerve palsy, iatrogenic fracture comminution, elbow impingement, return to pre-injury occupation, and functional shoulder scores. They did show a statistically significant increase in shoulder impingement and reduction of range of motion when using an intramedullary nail.
Figure A is a AP radiograph of a comminuted humeral shaft fracture. Illustration A is a radiograph of a humerus fixed with an intramedullary nail. Illustration B is a radiograph of a humerus fixed with a compression plate.
Incorrect Answers:

Question 45

An 18-year-old boxer sustained a blow to his right eye in a boxing match. Examination on the sideline reveals hyphema, reduced visual acuity and color vision, and a visual field cut. What is the next step in management? Review Topic

Explanation

With the examination demonstrating reduced visual acuity and visual field changes, emergent CT is needed to look for traumatic optic neuropathy from direct or indirect trauma. The most common mechanism is blunt facial trauma (78%), but penetrating trauma is also common (22%). The most common etiologies are sports and motor vehicle accidents. Fluorescein eye stain would only be useful for corneal abrasion or corneal foreign body. CT scans are often helpful for an orbital fracture, optic nerve sheath hemorrhage, optical canal fractures, skull fractures, foreign bodies, nonorbital facial fractures, or associated brain injuries. The presence of a fracture of the optic canal on a CT scan was a poor prognostic sign in a recent series by Goldenberg and associates. The treatment is controversial. Although treatment options include high-dose corticosteroids, retrobulbar steroid injection, optic canal decompression, and optic sheath fenestration, there is no consensus as to the optimum treatment. It has been reported that treatment does not alter the prognosis in children and adolescents. Only 29% to 44% of children and adolescent patients had significant improvement in visual acuity. Hyphema is a collection of free blood in the anterior chamber of the eye. It is the most common intraocular eye injury associated with sports as reported by Denyi and associates, and occurs in 24% of injured eye cases. At the time of injury, it occurs as a haze in the anterior chamber. An eye patch and ophthalmology evaluation in 2 days is inappropriate because timely evaluation in this scenario is important. High-dose steroids are often used for this injury but not before a full evaluation including a CT scan. Observation is not appropriate because the injury needs an urgent evaluation.

Question 46

A 28-year-old woman undergoes a closing-wedge high tibial osteotomy (HTO) for medial compartment overload after medial meniscectomy. Postsurgically, she reports improvement in her medial pain and resumes normal activities. About 9 months after her surgery, however, she reports burning pain in the front of her knee with running. Her examination reveals no joint line tenderness, mild pain with patellar compression, and limited patellar glides. What is the most likely cause of her symptoms?

Explanation

After HTO, particularly in patients who have been immobilized after a closing-wedge osteotomy, patella baja is a common finding. This can precipitate anterior knee pain or patellofemoral pain syndrome. Recurrence of medial joint overload is incorrect because the patient has no medial joint complaints. Nonunion is less likely with a closing-wedge osteotomy and likely will not result in anterior knee pain.

Question 47

Figures 1 and 2 are the AP and lateral radiographs of a 32-year-old man 10 years after anterior cruciate ligament (ACL) reconstruction. The patient now has worsening medial knee pain and a failed ACL with instability. What is the best surgical option?

Explanation

Lateral closing wedge (LCW) and medial opening wedge (MOW) high-tibial osteotomies (HTOs) can both correct varus knee alignment and stabilize the ACL–deficient knee. Increasingly, HTO is being proposed as a singular or concomitant procedure with ACL reconstruction for restoring knee stability and as a more reliable slope correction. LCW HTO demonstrates more reliable slope correction than does MOW HTO. Revision ACL with BTB allograft and meniscal transplant will not help early arthritis in varus alignment. Distal femoral osteotomy is usually considered for valgus knee. Pure sagittal osteotomy would not help the patient’s medial knee pain, arthritis, and malalignment.

Question 48

Figure 45 shows the radiograph of a 2-year-old patient who has progressive lumbar scoliosis as the result of hemivertebra. Examination reveals no associated cutaneous lesions, and an MRI scan shows no associated intraspinal anomalies. Treatment should consist of

Explanation

DISCUSSION: In a retrospective review of 10 patients treated with hemivertebra excision for hemivertebra in the levels of T12 to L3, the procedure was found to be safe and effective. The procedure provided an average curve correction of 67° and was greatest in patients who were younger than age 4 years at the time of surgery. Long anterior and posterior fusion with instrumentation is not the treatment of choice at this age. Either anterior hemiepiphyseodesis or posterior hemiarthrodesis in this isolated hemivertebra setting would be inadequate. Brace treatment is ineffective in management of the primary curvature.
REFERENCE: Callahan BC, Georgopoulos G, Eilert RE: Hemivertebral excision for congenital scoliosis. J Pediatr Orthop 1997;17:96-99.

Question 49

Which of the following patients is considered the most appropriate candidate for selective dorsal rhizotomy?

Explanation

DISCUSSION: While other surgical and nonsurgical options exist for management of spasticity, the criteria originally laid out by Peacock and associates describe the most appropriate candidate for rhizotomy as a patient with spastic diplegia who is between the ages of 4 to 8 years and has a stable gait pattern that is limited by lower extremity spasticity. Rhizotomy is not recommended in patients with athetosis because of unpredictable results. In addition, rhizotomy should be avoided in nonambulatory patients with spastic quadriplegia because it is associated with significant spinal deformities.
REFERENCES: Peacock WJ, Arens LJ, Berman B: Cerebral palsy spasticity: Selective posterior rhizotomy. Pediatr Neurosci 1987;13:61-66.
Oppenheim WL: Selective posterior rhizotomy for spastic cerebral palsy: A review. Clin Orthop 1990;253:20-29.
Mooney JF III, Millis MB: Spinal deformity after selective dorsal rhizotomy in patients with cerebral palsy. Clin Orthop 1999;364:48-52.

Question 50

In the initial evaluation of acute low back pain (duration of less than 4 weeks), plain radiographs are recommended in which of the following situations?

Explanation

DISCUSSION: Prolonged use of steroids is associated with compression fractures with minimal trauma. Indications for radiography with acute low back pain include possible tumor, fracture, infection, or cauda equina syndrome.
REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, Appendix A15.
Helfgott SM: Sensible approach to low back pain. Bull Rheum Dis 2001;3:50.

Question 51

A 2-year-old girl was born with the toe deformity shown in Figure 2. She has difficulty wearing shoes despite having adequate room in the toe box. Management at this time should consist of

Explanation

DISCUSSION: The patient has a congenital curly toe deformity of the third toe, and tenotomy of the toe flexors is highly effective for this problem. Stretching and taping are ineffective for this deformity. The position of the second toe is secondary; therefore, procedures on that toe are unnecessary and ineffective. The flexor to extensor transfer is a more complicated procedure that produces negligible results, or may even worsen the deformity. Resection arthroplasty is contraindicated because it causes abnormal growth of the toes.
REFERENCES: Hamer AJ, Stanley D, Smith TW: Surgery for curly toe deformity: A double-blind, randomized, prospective trial. J Bone Joint Surg Br 1993;75:662-663.
Ross ER, Menelaus MB: Open flexor tenotomy for hammer toes and curly toes in childhood. J Bone Joint Surg Br 1984;66:770-771.
Sullivan JA: The child’s foot, in Morrissy RT, Weinstein SL (eds): Lovell & Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 1077-1135.

Question 52

Figures 20a and 20b are the radiographs of a 19-year-old woman who was involved in a motor vehicle accident. What mechanism of injury is most consistent with the injury?

Explanation

The radiographs show a lateral compression pelvic ring injury with a displaced superior ramus fracture, or tilt fracture. Tilt fractures are most commonly caused by a lateral compression mechanism. These injuries are often seen in female patients and careful examination, including vaginal examination, is required to rule out open fractures. Lateral compression results in internal rotation, not external rotation, of the pelvic ring. Tilt fractures are not commonly seen with anterior-posterior compression injuries or vertical shear injuries. Sagittal translation is not a term used to describe pelvic ring injuries.

Question 53

What is the most common complaint in patients with a developmental radial head dislocation?

Explanation

DISCUSSION: Developmental dislocation of the radial head most frequently presents as a painless mass over the posterior aspect of the elbow. Patients do not have feelings of elbow subluxation but may report pain or clicking. Limitation of motion is most frequently found in the pronation and supination arc rather than in flexion and extension.
REFERENCES: Lloyd-Roberts GC, Bucknill TM: Anterior dislocation of the radial head in children-etiology: Natural history and management. J Bone Joint Surg Am 1977;58:402.
Hamilton W, Parks JC II: Isolated dislocation of the radial head without fracture of the ulna. Clin Orthop Relat Res 1973;97:94-96.

Question 54

Patients who have osteonecrosis of the humeral head and who have the best prognosis are those with which of the following conditions?

Explanation

DISCUSSION: The natural history of nontraumatic osteonecrosis varies greatly, so it is difficult to predict which patients will have severe arthrosis develop. Patients with sickle cell disease tend to have the most benign course. The most commonly reported cause of nontraumatic osteonecrosis is corticosteroid therapy. Fortunately, the incidence of osteonecrosis among patients treated with long-term systemic corticosteroids has fallen from more than 25% to less than 5% in recent years, owning to judicious steroid use and dosing. The interval between corticosteroid administration and the onset of shoulder symptoms is also variable, ranging from 6 to 18 months in one large series. This is comparable to the interval leading up to the onset of hip symptoms, which ranges from 6 months to 3 years or longer. The incidence of humeral head involvement has not been shown to vary with the underlying indication for steroid use.
REFERENCES: Hasan SS, Romeo AA: Nontraumatic osteonecrosis of the humeral head.

J Shoulder Elbow Surg 2002;11:281-298.
Mansat P, Huser L, Mansat M, et al: Shoulder arthroplasty for atraumatic avascular necrosis of the humeral head: Nineteen shoulders followed up for a mean of seven years. J Shoulder Elbow Surg 2005;14:114-120.

Question 55

Which of the following methods accurately describes the measurement of tip-apex-distance as it relates to placement of a lag screw in the femoral head?

Explanation

DISCUSSION: TIp-apex distance (TAD) as it relates to a lag screw in the femoral head is the summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs. This is shown in Illustration A.
TAD is a useful intraoperative indicator of deep and central placement of the lag screw in the femoral head, regardless of whether a nail or a plate is chosen to fix a fracture. A TAD of <25mm has been shown to minimize the risk of fixation cut-out in stable and unstable intertrochanteric hip fractures.
Baumgaertner et al examined factors leading to the failure of sliding hip screws (SHS) in the treatment of 198 intertrochanteric fractures. They determined that the tip-apex distance (TAD) is a reproducible, standard measurement to predict SHS failure. The average TAD for successful fractures was 24mm while the average TAD for failures was 38mm. No screw with a TAD <25mm failed. Calculation of the TAD is shown in Illustration B.
Kyle et al reviewed 622 intertrochanteric fractures. For unstable patterns, a SHS was superior to a fixed angle nail. Early ambulation and weight bearing contributed to improved results

Question 56

Figure 77 shows the clinical photograph of a 21-year-old male ice hockey player who sustained a blow to the jaw from another player’s hockey stick. Examination reveals an unstable jaw, mild bleeding with exposed bone, and malocclusion. What is the most serious acute complication of this injury?

Explanation

DISCUSSION: The most serious, acute complication of severe maxillofacial trauma is airway obstruction that can result in early death. It is most likely to be associated with multiple mandibular fractures or combined maxillary, mandibular, and nasal fractures as reported by Seyfer and Hansen and Rohrich and Shewmaker.
The mandible suspends the tongue anteriorly. When the mandible is fractured and the patient is supine, the tongue falls posteriorly and obstructs the airway. Soft-tissue swelling around the injured oronasal structures can also result in a loss of airway patency. Endotracheal or nasotracheal intubation is often impossible and a surgical airway may often have to be created to prevent death by asphyxiation. Other injuries that may require immediate attention include head or cervical spine injury and hemorrhage. A cerebrovascular accident is also less common but is associated with injury to the common carotid artery or its branches. Periodontal disease is generally a long-term complication from dental injuries. Hearing loss is not a common complication of dental and facial trauma.
REFERENCES: Seyfer AE, Hansen JE: Facial trauma, in Moore EF, Feliciano DV, Maddox KL (eds): Trauma, ed 5. New York, NY, McGraw-Hill, 2004, pp 423-444.
Rohrich RJ, Shewmake KB: Evolving concepts of craniomaxillofacial fracture management. Clin Plast
Surg 1992;19:1-10.

Question 57

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

Explanation

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

Question 58

A 5-year-old boy has had midfoot pain with activity for the past 3 months. He has no pain at rest. Radiographs are shown in Figures 29a and 29b. Management should consist of

Explanation

DISCUSSION: The radiographs show classic findings for Koehler’s disease (osteochondrosis of the navicular). The patient’s age and clinical history are typical for this self-limiting condition. Patients will improve with time, but the duration of symptoms is much shorter if the patient is placed in a cast. There is no role for surgery in this disease.
REFERENCE: Williams GA, Cowell HR: Koehler’s disease of the tarsal navicular. Clin Orthop 1981;158:53-58.

Question 59

A 66-year-old woman was a restrained passenger in an automobile accident. She sustained a direct blow to her nondominant left hand as the airbag in her automobile deployed and she now reports pain, swelling, and difficulty moving her fingers. Radiographs are shown in Figures 58a and 58b. Appropriate definitive treatment should consist of

Explanation

DISCUSSION: While most isolated metacarpal fractures can be treated nonsurgically, multiple metacarpal fractures are inherently unstable due to the loss of support that an intact adjacent metacarpal provides; therefore, treatment should consist of surgical fixation of all three metacarpal fractures.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC, et al (eds): Green’s Operative Hand Surgery, ed 5. Philadelphia, PA, Elsevier, 2005, p 286.
Faraj AA, Davis TR: Percutaneous intramedullary fixation of metacarpal shaft fractures. J Hand Surg Br 1999;24:76-79.

Question 60

Which of the following is considered an advantage of arthroscopic distal clavicle excision compared with open distal clavicle excision?

Explanation

DISCUSSION: Arthroscopic versus open distal clavicle excision has the advantage of allowing evaluation of the glenohumeral joint arthroscopically prior to moving into the subclavicular and subacromial space to perform the distal clavicle excision. This can be of value in both confirming the diagnosis as well as avoiding diagnostic errors. Berg and Ciullo showed that
in 20 patients who underwent open distal clavicle excision that resulted in failure, 15 of those patients had a superior labral anterior posterior (SLAP) lesion. Of these 15 patients who had the lesion treated surgically, 9 went on to a good to excellent result after the surgery was performed arthroscopically. Fewer complications, lower infection rate, and decreased surgical time have not been documented in the literature. Arthroscopic technique sacrifices the inferior acromioclavicular ligament and preserves the superior acromioclavicular ligament.
REFERENCES: Berg EE, Ciullo JV: The SLAP lesion: A cause of failure after distal clavicle resection. Arthroscopy 1997;13:85-89.
Lemos MJ, Tolo ET: Complications of the treatment of acromioclavicular and sternoclavicular joint injuries, including instability. Clin Sports Med 2003;22:371-385.

Question 61

What is the most common complication associated with scalene regional anesthesia for shoulder procedures?

Explanation

DISCUSSION: Failure of the scalene block, necessitating general anesthesia or the immediate administration of narcotic medications, is the most common complication, occurring in 3% to 18% of patients. Cardiac arrest or cardiovascular collapse has been reported in anecdotal occurrences. Seizure that is the result of intravascular injection of local anesthetic is a rare complication, with an incidence reported of 0% to 6%. Neurologic complications, including laryngeal and phrenic nerve injuries, are rare although parathesias lasting up to 2 weeks have been reported in up to 3% of patients.
REFERENCES: Weber SC, Jain R: Scalene regional anesthesia for shoulder surgery in a community setting: An assessment of risk. J Bone Joint Surg Am 2002;84:775-779.
Conn RA, Colfield RH, Byer DE, Lindstromberg JW: Interscalene block anesthesia for shoulder surgery. Clin Orthop 1987;216:94-98.

Question 62

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

Explanation

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

Question 63

A 72-year-old man was scheduled for left total knee replacement. He has a history of hypertension and deep venous thrombosis (DVT) in his right lower extremity after an ankle fracture 2 years ago that was treated nonsurgically. The patient asked about the recommended types of DVT prophylaxis or investigations. Based on the 2011 AAOS Clinical Practice Guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty , what is an acceptable option?

Explanation

The 2011 AAOS guideline, Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty, recommends the combined use of mechanical and pharmacological prophylaxis in patients who have a history of previous thromboembolism. This recommendation is a consensus opinion of the work group that established these guidelines because there is no other reliable evidence for this clinical scenario. There is strong evidence against the use of routine duplex scans in patients undergoing hip and knee replacement. The remaining two responses are less appropriate because they do not include the use of mechanical prophylaxis immediately after surgery.

Question 64

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

Explanation

Question 65

CLINICAL SITUATION Figures 1 through 3 are the radiographs of a 25-year-old man who is brought to the emergency department after a motorcycle collision. He is complaining of isolated knee pain. Examination reveals swelling, popliteal ecchymosis, joint line pain, and limited knee joint motion. His pulses and sensation are normal. The surgical approach for definitive reduction and stabilization of this pattern is

Explanation

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

Question 66

Which of the following associated type acetabular fracture patterns is defined based on the fact that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the sacroiliac joint?

Explanation

DISCUSSION: There are 5 simple and 5 associated fracture types according to the classification system created by Judet and Letournel. The key feature which distinguishes both column fractures from other associated types is that all articular segments are detached from the intact portion of the ilium, which remains attached to the sacrum through the SI joint. Although the transverse plus posterior wall, T-shaped, and anterior plus posterior hemi-transverse fractures all show involvement of the anterior and posterior columns, they are not “both columns” because a portion of the articular surface remains in its normal position, attached to intact ilium. The intact ilium is responsible for the "spur sign" noted most prominently on the obturator oblique radiograph.

Question 67

Examination of a 10-year-old girl with a hypoplastic breast and atrophic pectoralis major may also reveal which of the following findings?

Explanation

DISCUSSION: Poland’s syndrome has four main features: 1) short digits as the result of absence or shortening of the middle phalanx; 2) syndactyly of the short digits usually consisting of a simple, complete type; 3) hypoplasia of the hand and forearm; and 4) absence of the sternocostal head of the pectoralis major on the same side.
REFERENCES: Wilson MR, Louis DS, Stevenson TR: Poland’s syndrome: Variable expression and associated anomalies. J Hand Surg 1988;13:880-882.
Poland A: Deficiency of the pectoralis muscle. Guys Hosp Rep 1841;6:191.

Question 68

Which nerve root contributes to both the sciatic and femoral nerves?

Explanation

DISCUSSION
The lumbosacral plexus is formed from the lumbar and sacral roots that are redistributed into the obturator, femoral, and sciatic nerves. The obturator nerve is composed of the L1, L2, and L3 roots. The femoral nerve has contributions from the L3 and L4 roots. The sciatic nerve contains the L4, L5, S1, and lower sacral roots. Therefore, only the L4 root contributes to the femoral and sciatic (via the lumbosacral trunk) nerves, which allows it to innervate the quadriceps and the anterior tibialis muscles.
RECOMMENDED READINGS

Question 69

Figure 16 shows the lateral radiograph of a patient who is scheduled to undergo an anterior cruciate ligament (ACL) reconstruction. If the graft is tensioned at 20° of flexion and the femoral tunnel is created by passing a reamer over the guide wire marked “A,” the resulting ligament reconstruction will excessively

Explanation

DISCUSSION: If the femoral tunnel is created using guide wire A, it will be too far anterior in the intercondylar notch. The distance between a central tibial insertion for the ACL and an anterior femoral tunnel will progressively increase as the knee is flexed. Therefore, if the graft is tensioned near extension, the ligament will excessively tighten as the knee flexes past 90°. This will result in restricted knee flexion or failure of the graft as full flexion is gained. There will be little effect on the ligament as it extends from 20° to 0° of flexion. If the graft is tensioned in significant flexion (greater than 60°), it will be excessively loose as the knee fully extends.
REFERENCES: Daniel DM, Fritschy D: Anterior cruciate ligament injuries, in DeLee JC, Drez D Jr (eds): Orthopaedic Sports Medicine: Principles and Practice. Philadelphia, PA, WB Saunders, 1994, pp 1313-1360.
Larson RL, Tailon M: Anterior cruciate ligament insufficiency: Principles of treatment. J Am Acad Orthop Surg 1994;2:26-35.

Question 70

Rupture of the structure shown in the axial cross and the sagittal sections in Figures 100a and 100b causes weakness in

Explanation

DISCUSSION 87
The structure identified is the distal biceps tendon. Rupture of this tendon causes weakness in both flexion and supination. The biceps tendon does not affect extension or pronation.
RECOMMENDED READINGS
Baker BE, Bierwagen D. Rupture of the distal tendon of the biceps brachii. Operative versus non-operative treatment. J Bone Joint Surg Am. 1985 Mar;67(3):414-7. PubMed PMID: 3972865. View Abstract at PubMed
Mazzocca AD, Spang JT, Arciero RA. Distal biceps rupture. Orthop Clin North Am. 2008 Apr;39(2):237-49, vii. doi: 10.1016/j.ocl.2008.01.001. Review. PubMed PMID: 18374814. View Abstract at PubMed

Question 71

A 5-year-old boy has had pain in the right foot for the past month. Examination reveals tenderness and mild swelling in the region of the tarsal navicular. Radiographs are shown in Figure 30. Management should consist of

Explanation

DISCUSSION: The child has the classic findings of Kohler’s disease or osteochondrosis of the tarsal navicular. The cause of this condition is not known, but osteonecrosis and mechanical compression have been proposed. Children generally report midfoot pain over the tarsal navicular and limping. Physical findings include tenderness, swelling, and occasionally redness in the region of the tarsal navicular. Radiographs show sclerosis and narrowing of the tarsal navicular. The natural history of the condition is spontaneous resolution and reconstitution of the navicular. Symptomatic treatment with restriction of weight bearing or casting is recommended.
REFERENCES: Karp M: Kohler’s disease of the tarsal scaphoid. J Bone Joint Surg

1937;19:84-96.
Borges JL, Guille JT, Bowen JR: Kohler’s bone disease of the tarsal navicular. J Pediatr Orthop 1995;15:596-598.

Question 72

Figure 3a is the initial radiograph of a 19-year-old man who sustained a closed clavicle fracture. Figures 3b and 3c show postoperative radiographs. If the patient had been treated nonsurgically, which of the following would most likely occur?

Explanation

Recent studies comparing surgical treatment with nonsurgical management in displaced clavicle fractures have revealed a decreased rate of malunion and nonunion with surgery. In addition, significant malunions can lead to functional deficits at the shoulder. Thus, with open reduction and internal fixation and anatomic or near-anatomic reduction, there should be a higher likelihood of normal shoulder strength and function. Infection and local sensory deficits would not be expected with nonsurgical management, whereas surgical treatment has a small risk of infection and a high likelihood of sensory deficits from iatrogenic damage to the supraclavicular nerves.

Question 73

A player on a professional football team sustains a knee injury and is diagnosed with an anterior cruciate ligament rupture. When employed as the team physician, your ethical obligation is to inform

Explanation

When you are employed as a team physician, you are obligated to inform the players and the team organization of all athletically relevant medical issues. This differs significantly from the normal rule of patient confidentiality. If the player came to see you and you were not the team physician, you may not inform the team unless the player so desires. As the team physician, you are not obligated to inform the media.

Question 74

Figure 24 shows the radiograph of an otherwise healthy 56-year-old patient who reports hip pain after undergoing a primary cementless hip replacement 4 months ago. The next most appropriate step should consist of

Explanation

DISCUSSION: Periosteal new bone formation is a warning sign of prosthetic infection. Indomethacin may prevent heterotopic ossification if given early enough; however, it is irrelevant in this patient. A C-reactive protein and a sed rate are useful screening studies that add to the predictive value of the radiographs and may be performed routinely if sepsis is suspected. A bone scan obtained 4 months after surgery would show increased uptake in all cases. If results of a sed rate and C-reactive protein are normal, then a biopsy should be considered to rule out a neoplasm.
REFERENCE: Fitzgerald RH Jr: Infected total hip arthroplasty: Diagnosis and treatment. J Am Acad Orthop Surg 1995;3:249-262.

Question 75

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

Explanation

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

Question 76

Induction coupling stimulates bone growth through all of the following direct effects EXCEPT:

Explanation

Induction coupling stimulates bone growth by increasing expression of BMP7, BMP2, TGF-beta1, and by increasing osteoblasts proliferation. Induction coupling has not been shown to have the effect of decreasing osteoclast differentiation.
In basic science studies, electrical stimulation (i.e. induction coupling), has been shown to promote bone healing via release of growth factors that induce osteoblast differentiation/proliferation. Electrical current can be placed around bone in various ways, creating a current to stimulate growth factor release and subsequent osteoblast proliferation.
Aaron et al. summarized, in a systematic review, the effects of various types of electrical stimulation on bone and bone healing. Regardless of type (i.e. inductive coupling, capacitive coupling, direct current), they report electricity and/or electromagnetic fields promote gene expression of growth factors that promote an osteogenic environment.
Illustration A depicts a cathode placed directly to allograft with a subcutaneously placed electrical stimulator. Illustration B depicts cathodes placed anteriorly and posteriorly around the hip, connected to an outside power source to create the necessary current. Illustration C depicts an inductive coil placed laterally on the skin in order to create an electrical current.
Incorrect answers:

Question 77

Standard guidelines necessitate the use of intraoperative neurophysiological monitoring for patients undergoing surgery for which condition?

Explanation

DISCUSSION
There are currently no official guidelines on the appropriate use of neuromonitoring in spine surgery. In general, use of neuromonitoring is at surgeon discretion and often is based on the surgeon's perceived risk for neurologic injury during surgery and medicolegal concerns. In most reports,
neuromonitoring is considered useful in cases of deformity correction, spinal cord decompression, instrumentation placement, and revision surgery. However, even for some of these cases, studies have shown limited benefits of neuromonitoring and substantial associated costs.
RECOMMENDED READINGS
Lall RR, Lall RR, Hauptman JS, Munoz C, Cybulski GR, Koski T, Ganju A, Fessler RG, Smith ZA. Intraoperative neurophysiological monitoring in spine surgery: indications, efficacy, and role of the preoperative checklist. Neurosurg Focus. 2012 Nov;33(5):E10. doi: 10.3171/2012.9.FOCUS12235. Review. PubMed PMID: 23116090. View Abstract at PubMed Peeling L, Hentschel S, Fox R, Hall H, Fourney DR. Intraoperative spinal cord and nerve root monitoring: a survey of Canadian spine surgeons. Can J Surg. 2010 Oct;53(5):324-8. PubMed PMID: 20858377. View Abstract at PubMed
Garces J, Berry JF, Valle-Giler EP, Sulaiman WA. Intraoperative neurophysiological monitoring for minimally invasive 1- and 2-level transforaminal lumbar interbody fusion: does it improve patient outcome? Ochsner J. 2014 Spring;14(1):57-61. PubMed PMID: 24688334. View Abstract at PubMed

Question 78

A 6-year-old boy is being treated for acute hematogeneous osteomyelitis of the distal femur with intravenous antibiotics. The best method to determine the success or failure of initial treatment is by serial evaluations of which of the following studies? Review Topic

Explanation

Successful antibiotic treatment of acute osteomyelitis should lead to a rapid decline in the CRP. The CRP is the most sensitive study to follow the treatment of osteomyelitis. The CRP should decline after 48 to 72 hours of appropriate treatment. CBC and ESR are helpful in initial evaluation and diagnosis, but remain abnormal in the early phase of treatment regardless of response. Imaging studies are useful for surgical planning or secondarily if the CRP remains elevated.

Question 79

Figures 1 and 2 display the radiographs obtained from a woman who had volar plating of the distal radius 8 months earlier. Two days ago, she noticed she could not actively extend her thumb. What is the most appropriate treatment that would restore active thumb extension?

Explanation

EXPLANATION:
Although the fracture is aligned in anatomic position, prominence of a least one of the distal screws is evident on the lateral radiographic view. The prominent screw is the most likely cause of the EPL tendon rupture. If the patient chooses surgical treatment, the best option would be removal of the offending hardware combined with extensor indicis proprius to EPL tendon transfer. Intercalary grafting would also be an acceptable option. If the tendon transfer were to be performed alone, the prominent screw(s) could rupture the transferred tendon as well. Also, it is rarely possible to repair the EPL tendon primarily in such cases, because this rupture is an attrition type. Casting would obviously not provide any benefit in this situation, and IP arthrodesis would not be the first surgical treatment option. This problem can be avoided by using shorter screws or not placing screws in plate holes that direct screws into the third dorsal extensor compartment. Intraoperative fluoroscopy and special views, such as the carpal shoot-through view, are useful for avoiding this complication.

Question 80

A high school football player asks you about an oral supplement that increases body mass and improves sprint times. He would like to use it to improve performance. What is the most likely agent? Review Topic

Explanation

The supplement is creatine. Approximately 17% of high school athletes and about 30% of high school football players use creatine. Creatine is a protein synthesized in the liver and the kidney, circulates in the bloodstream, and is incorporated into muscle. Its use is associated with increased muscle mass, short-term improvement in sprinting, and may allow for increased anaerobic resistance performance. Caffeine and ephedrine are taken orally but do not increase muscle mass. Testosterone and human growth hormone are both associated with increased body mass but must be injected.

Question 81

A 25-year-old man has had an insidious onset of left hip pain over the past 11 months. A radiograph, coronal MRI scan, and histopathologic specimens are seen in Figures 2a through 2d. What is the most likely diagnosis?

Explanation

DISCUSSION: Ewing’s sarcoma is the second most common primary sarcoma of bone in children and young adults. It is a malignant round cell tumor with uncertain histogenesis. Sheets of uniform small round blue cells with a high nuclear-to-cytoplasm ratio and the absence of osteoid formation differentiate this histologic diagnosis from the other conditions. Immunohistochemical staining and molecular diagnostic studies are useful to verify the diagnosis.
REFERENCE: Sucato DJ, Rougraff B, McGrath BE, et al: Ewing’s sarcoma of the pelvis: Long-term survival and functional outcome. Clin Orthop 2000;373:193-201.

Question 82

..Figures 107a through 107c are the radiograph, CT, and bone scan of a 68-year-old man. While walking, he collapsed and was unable to ambulate because of pain and deformity in his right leg. What is the most appropriate next step?

Explanation

RESPONSES FOR QUESTIONS 108 THROUGH 111
Glomus tumor
Diffuse pigmented villonodular synovitis (PVNS)
Extra-abdominal fibromatosis
Schwannoma
Hemangioma
Please match the characteristics below to the condition listed above.

Question 83

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 84

0 mg/L (reference range, 0.08-3.1 mg/L) and erythrocyte sedimentation rate (ESR) is 5 mm/h (reference range, 0-20 mm/h). What is the most appropriate next step in management of the patient?

Explanation

Proximal tibial osteotomy
Distal femoral osteotomy
Lateral unicompartmental arthroplasty
Total knee arthroplasty
Arthroscopic partial lateral meniscectomy Corrent answer: 2
This patient is a good candidate for a joint-preserving procedure. Her symptoms and radiographic findings reveal valgus malalignment of the knee with narrowing of the lateral joint space. The alignment can be corrected with a varus-producing distal osteotomy. Most patients do not proceed to knee arthroplasty for at least 10 years after this procedure. Osteotomy is preferred over partial or total knee arthroplasty because of the patient's young age.
Varus proximal tibial osteotomy would result in joint line obliquity.
An orthopaedic surgeon noticed a displaced calcar fracture during stem insertion when performing total hip arthroplasty using cementless fixation. What is the most appropriate course of action?
Intraoperative exploration to determine the extent of the fracture
Use of a longer stem without fixation of the calcar fracture
Complete insertion of the stem and measures to protect the patient against full weight bearing for 4 weeks
Removal of the stem, internal fixation of the fracture, and definitive reconstruction at a later stage after the fracture has healed
Calcar fractures can occur with both cemented and cementless stem fixation during surgery. The distal extent of the fracture must be identified either by direct visualization or intraoperative radiograph prior to fixation or implantation of the femoral component. The recommended treatment is to fix the calcar fracture with cerclage wires/cables to restore the mechanical stability of the femoral metaphysis. The same stem can be inserted successfully. The majority of these fractures unite without adverse stem fixation problems.
A 48-year-old woman had an 8-month history of spontaneous onset of left medial knee pain. She was otherwise healthy with an unremarkable past medical history. Prior to the onset of knee pain, she jogged, played tennis, and golfed regularly. She wished to remain active. Examination showed a fit woman with a BMI of 26, a stable left
knee with full range of motion, and some mild medial joint line tenderness. Radiograph results were normal. An MRI scan showed diffuse grade 3 and a focal area of grade 4 chondromalacia on the medial femoral condyle. The medial meniscus had a degenerative signal but no tear. The remainder of the knee showed no additional pathology. What is the most appropriate initial treatment?
Lateral heel wedge
Low-impact aerobic exercises
Glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day
Arthroscopic debridement and microfracture of the focal area of grade 4 chondromalacia to reduce risk for progression
This patient has early medial compartmental osteoarthritis of her knee. According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee (Non-Arthroplasty), there is Level 1 evidence and an "A" recommendation for the use of low-impact aerobic exercises. The guideline also has "A" recommendations with Level 1 evidence indicating that glucosamine and chondroitin should not be prescribed and that arthroscopic debridement not be performed in the absence of symptoms of a meniscal tear or loose body. Lateral heal wedge is not appropriate; the AAOS guideline provides a "B" recommendation with Level 2 evidence indicating that a lateral heal wedge not be prescribed.
Figure 36 is the postoperative photograph of a patient who underwent a total knee arthroplasty 10 days after surgery. Knee aspiration suggests a Streptococcus infection.

Stop physical therapy and institute oral antibiotics.
Stop physical therapy and institute intravenous (IV) antibiotics.
Open irrigation and debridement, polyethylene spacer exchange, and IV antibiotics
Remove components and insert an antibiotic spacer.
An acute postoperative infection during the first 2 to 4 weeks should be treated with a return to the operating room for open irrigation and debridement of the wound. Polyethylene spacer exchange aides in washing out the entire knee joint. IV antibiotics are also indicated in this situation. To address persistent wound drainage, there is no role for oral or IV antibiotics alone. Removal of the arthroplasty components is recommended for infections after the initial 2- to 4-week postoperative period. However, several recent publications demonstrate a failure rate higher than 50% when the organism is a methicillin-resistant Staphylococcus aureus. Six weeks after surgery, this scenario is no longer considered an acute postoperative infection, and most authors recommend a 2-stage protocol with removal of components and placement of an antibiotic-impregnated cement spacer and 4 to 6 weeks of IV antibiotics.
What is the difference in outcome when comparing high tibial osteotomy (HTO) to total knee arthroplasty (TKA)?
TKA has a longer recovery period than HTO.
HTO provides more complete pain relief than TKA.
HTO is more reliable in older patients than TKA.
HTO outcomes among thin, active, young patients who undergo this procedure approach outcomes associated with TKA.
The ideal candidate for HTO is a thin, active person with a stable knee, unicompartmental knee symptoms, and age younger than 60. TKA offers a shorter recovery period and more complete pain relief than HTO. TKA is believed to be more reliable than HTO for patients older than age 60.
Figure 39 is a radiograph of a 72-year-old man who underwent an open reduction and internal fixation of a right femoral neck fracture. After 3 months he started to develop pain, and during the next 8 months he complained of progressive pain and shortening of the hip. What is the most appropriate treatment?

Girdlestone
Total hip replacement
Hardware removal
Hardware removal with revision open reductions and internal fixation Corrent answer: 2
Even though a relatively short amount of time has passed since the index surgery, this patient has developed significant osteonecrosis that has caused collapse of the bony structures and the hardware prominent. Total hip replacement gives the most efficient pain relief. Hardware removal with or without re-reduction does not provide reliable pain relief. A girdlestone does not allow the patient to function.
Figure 40 is the radiograph of a 68-year-old woman who has right knee pain that is limiting her activity and severe preoperative valgus deformity. During total knee arthroplasty, what pathologic features are typically encountered?

Lateral femoral hypoplasia
Internal rotation of the tibia relative to the femur
Medial patella tracking
Tight medial collateral ligament Corrent answer: 1
In patients with severe valgus deformity, problems frequently encountered include loose or attenuated medial collateral ligament, tight lateral retinaculum and lateral ligamentous structures (lateral collateral, posterolateral corner), atrophic lateral femoral condyle, lateral patella tracking, and external rotation of the tibia relative to the femur. The hypoplastic lateral condyle can cause internal rotation of the anteroposterior cutting block if the posterior condyler line is used for rotational alignment. The medial soft tissues are typically attenuated and stretched.
A 59-year-old active woman underwent elective total hip replacement using a posterior approach. She had minimal pain and was discharged to home 2 days after surgery. Four weeks later she dislocated her hip while shaving her legs. She underwent a closed reduction in the emergency department. Postreduction radiographs show a reduced hip with well-fixed components in satisfactory alignment. What is the most appropriate management of this condition from this point forward?
Observation and patient education regarding hip dislocation precautions
Revision to a larger-diameter femoral head
Revision to a constrained acetabular component
Application of a hip orthosis for 3 months Corrent answer: 1
First-time early dislocations are often successfully treated without revision surgery, especially when there is no component malalignment. In this clinical scenario, it appears the patient would benefit from better education about dislocation precautions. Hip orthoses are of questionable benefit unless the patient is cognitively impaired. Revision surgery can be successful, but is usually reserved for patients with recurrent dislocations.
Patellar pain, subluxation, or dislocation after total knee arthroplasty can result from which of the following component orientations?
Internal rotation of the tibial component
Lateralization of the tibial component
Lateralization of the femoral component
External rotation of the femoral component Corrent answer: 1
Internal rotation of the components of a total knee arthroplasty, both the tibial and femoral components, can lead to symptoms ranging from patellar pain to dislocation. Most researchers agree that proper external rotation of the femoral component is parallel or nearly so to the femoral epicondylar axis with the knee in the 90-degree flexed position. Proper rotational positioning of the tibial component places the midportion of the tibial component rotationally aligned within the medial one-third of the tibial tubercle. Internal rotation of the tibial component causes relative lateralization of the tibial tubercle and the extensor mechanism. Lateralization of the femoral component moves the trochlear groove laterally. Lateralization of the tibial component moves the tibial tubercle medially, which may be beneficial to patellar tracking.
How does the risk for periprosthetic infection after total knee arthroplasty compare to risk for infection after total hip arthroplasty?
Higher in primary arthroplasty
Lower in primary arthroplasty
Lower in revision arthroplasty
Equivalent in both primary and revision arthroplasty Corrent answer: 1
Risk for periprosthetic infection is higher in the knee (1%-2%) than it is in the hip (0.3%-1.3%). The risk for infection is higher after revision joint replacement surgery compared to primary joint replacement surgery.
Osteoarthritis is not associated with a higher risk for periprosthetic infection, but certain inflammatory conditions such as rheumatoid arthritis and psoriatic arthritis place patients at higher risk for postoperative infection.
What factor is associated with a higher risk for dislocation after total hip arthroplasty?
Male gender
Previous hip surgery
A direct lateral surgical approach
Metal-on-metal bearing surfaces Corrent answer: 2
Dislocation after total hip arthroplasty is a multifactorial problem. Numerous risk factors may act independently or cumulatively to increase risk for this complication. Previous hip surgery of any kind is associated with a twofold increased risk for dislocation. Other risk factors include female gender, impaired mental status, inflammatory arthritis, and older age. Numerous studies have shown a lower dislocation rate with a direct lateral approach, although surgical techniques such as capsular repair have significantly lowered the incidence of dislocation after using the posterior approach. Metal-on-metal bearings have been associated with other complications such as adverse tissue reactions but are often used with larger-diameter bearings, which pose lower risk for dislocation.
What surgical technique has been associated with increased risk for recurrent dislocation after revision total hip arthroplasty?
Posterior capsulorrhaphy
Use of a jumbo cup
Use of a lateralized liner
Use of a larger femoral head diameter Corrent answer: 2
When addressing recurrent dislocation after total hip arthroplasty, surgical considerations that must be addressed include approach, soft-tissue tension, component positioning, impingement, head size, and acetabular liner profile. These considerations most often involve tensioning or augmentation of soft tissues, as in capsulorrhaphy or trochanteric advancement; correction of malpositioned components; use of larger femoral head sizes that increase motion before impingement; improving the head-to-neck ratio; and increasing femoral offset. The use of a larger-diameter acetabular component may lead to soft-tissue overgrowth around the liner, causing impingement and increasing the risk for recurrent dislocation.
A 67-year-old active man returns for routine follow up 12 years after hip replacement. He has no hip pain. Radiographs revealed a
well-circumscribed osteolytic lesion around a single acetabular screw. All hip components were perfectly positioned. Six months later, comparison radiographs show an increase in the size of the osteolytic lesion. A CT scan shows a well-described lesion that is 3 cm at its largest diameter and is localized around 1 screw hole with an eccentric femoral head. What treatment is appropriate, assuming well-fixed cementless total hip components exist?
Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting
Revision of the acetabular component to a newer design without screws
Removal of the screw, revision of the polyethylene liner, and stem cell injection into the lytic lesion
Removal of the offending screw from the metal socket and placement of a new polyethylene liner in the existing socket
With a well-fixed acetabular metal shell and a localized osteolytic lesion, good outcomes can be expected with liner revision in this clinical scenario with retention of the metal socket, assuming no damage to the components or other unexpected findings during revision surgery. Here, complete cup revision is not warranted considering the appropriate implant position. Beaule and associates reviewed 83 consecutive patients (90 hips) in which a well-fixed acetabular component was retained in clinical scenarios such as the one described; no hip showed recurrence or expansion of periacetabular osteolytic lesions. If the metal cup is unstable, or if the osteolytic lesion is not amenable to debridement through the screw hole, acetabular component revision may be indicated.
What has been identified as a risk factor for total knee arthroplasty failure after previous high tibial osteotomy?
Body mass index higher than 35
Female gender
Preoperative stiffness
Advanced age
Increased weight, male gender, young age at the time of total knee arthroplasty, laxity, and limb malalignment preoperatively have been identified
as risk factors for early failure for total knee arthroplasty following high tibial osteotomy.
You are caring for an 18-year-old boy with severe hip arthritis and pain from a missed slipped capital femoral epiphysis. You decide that a hip arthrodesis is the best treatment option. What is the optimum position for a hip arthrodesis to maximize function and prevent complications?
0° external rotation, 0° adduction, 0° hip flexion
5° external rotation, 5° adduction, 20° hip flexion
5° external rotation, 15° abduction, 5° hip flexion
15° external rotation, 0° adduction, 20° hip flexion
15° external rotation, 15° abduction, 5° hip flexion
Hip arthrodesis is a salvage procedure for patients with hip arthritis without ipsilateral knee, contralateral hip, or lumbar spine pathology. The optimal position for hip arthrodesis is 5 degrees of adduction, 5-10 degrees of external rotation, and 20-35 degrees of hip flexion.
In their review, Beaule et al. discuss the current indications and techniques regarding hip arthrodesis including appropriate leg position, surgical techniques, methods to optimize function, and later conversion to hip arthroplasty.
Callaghan et al. evaluated the long term efficacy (20-25 yrs) of hip arthrodesis. They found the onset of ipsilateral knee, contralateral hip, or lumbar spine pathology usually began 20 years after the arthrodesis. Of their patients, they found a 15% rate of conversion to hip arthroplasty by 20 years.
What limits indications for the use of constrained liners?
Association with periprosthetic fracture
Technical difficulty associated with insertion
High costs associated with their use
High failure rates associated with their use Corrent answer: 4
Because of reports of relatively high failure rates associated with constrained liners, indications are limited to continued instability after appropriate component position or deficient abductor mechanism and instability. Neither cost nor technical insertion issues are relevant with regard to indications for use. Periprosthetic fractures are not associated with constrained liner usage.
What serum inflammatory marker has the highest correlation with periprosthetic joint infection?
C-reactive protein
Serum white blood cell count
Erythrocyte sedimentation rate
Interleukin 6 (IL-6)
Although CRP and ESR can be elevated in the setting of infection, IL-6 has been shown to have the highest correlation with infection. Serum white blood cell count has been shown to be ineffective in correlating with periprosthetic joint infection.
A 68-year-old man reports hip pain 15 years after successful cementless total hip arthroplasty. Radiographs show 3 mm of linear wear of the modular acetabular liner and a retro-acetabular osteolytic lesion. Both the titanium femoral and acetabular components appear to be well fixed. The orthopaedic surgeon recommends revision of the acetabular liner and femoral head. This patient is at increased risk for
dislocation.
periprosthetic fracture.
infection.
progressive osteolysis.
Isolated acetabular liner revision is frequently performed in cases of liner wear and periprosthetic osteolysis in the absence of acetabular component loosening. Many reports have documented an increased incidence of dislocation following this type of revision surgery. This dislocation rate can be reduced by using a larger-diameter femoral head at the time of revision. If the
acetabular component is loose or malpositioned, it should be revised. If the locking mechanism is damaged, then a replacement liner may be cemented into the well-fixed shell. Numerous studies have shown that many osteolytic lesions will reduce in size or heal without bone grafting, and removal of the source of wear debris will arrest the progression of osteolysis. The risk for periprosthetic fracture and infection are lower than risk for dislocation in this setting.
A 61-year-old man with a body mass index of 31 had a 6-month gradual onset of right medial knee pain. Examination revealed a small effusion, stable ligaments, a normally tracking patella, and mild medial joint line tenderness. Standing radiographs show mild medial joint space narrowing. Effective treatment at this stage of early medial compartmental osteoarthritis includes
glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day.
weight loss through dietary management and low-impact aerobic exercises.
arthroscopic debridement and lavage.
a valgus-directing brace.
According to the 2008 AAOS Clinical Practice Guideline, Treatment of Osteoarthritis of the Knee (Non-Arthroplasty), Level 1 evidence confirms that weight loss and exercise benefit patients with knee osteoarthritis. The other responses have either inclusive evidence (a valgus-directing brace) or no evidence to support their use (glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day and arthroscopic debridement and lavage).
The range of knee mobility after total knee replacement is multifactorial and dependent upon implant design, surgical implantation accuracy, and patient-specific variables. What total knee implant design is associated with the most knee flexion after total knee replacement?
Highly conforming articular surface geometry
Higher-flexion femoral component design manufactured to allow the most knee flexion
Posterior cruciate-stabilized implant, with or without a higher flexion
manufacturing modification
Posterior cruciate-retaining design with a mobile bearing, custom implanted based on CT scan data
A posterior cruciate-stabilized implant has the best support in the literature in terms of the most favorable range of motion after knee arthroplasty, regardless of whether the femoral component is designed with a higher flexion variation. The higher flexion design is a manufacturing variation that is intended to increase motion by clearing the posterior condyles in flexion.
Although the knee may not gain more flexion, this design allows for more safety in deep flexion. The long-term outcomes of increased stresses on the polyethylene are not known, however. By itself, a higher-flexion design does not lead to increased knee mobility. The effects of mobile bearings, custom CT scan-based knee implantation, and highly conforming designs on ultimate knee range of motion are uncertain.
In total knee arthroplasty, in vitro testing has shown that crosslinking 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?
Increased ductility
Increased wettability
Diminished fatigue strength
Decreased resistance to abrasive wear Corrent answer: 3
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 identified as causing implant failure in most recent clinical trials, but remain the most important mechanical issues associated with current material processing methods.
What factor is associated with a high risk for developing pseudotumors after metal-on-metal hip resurfacing?
Large-diameter components
Age 40 or older for men
Age 40 or younger for women
Diagnosis of primary osteoarthritis Corrent answer: 3
The recent experience of a large clinical cohort revealed the most likely risk factors as female gender, age younger than 40, small components, and the diagnosis of hip dysplasia causing osteoarthritis. Failure was least likely among men and procedures involving larger components. These data have prompted some authors to caution against use in women and to primarily target candidates who are men younger than age 50. Small components may be more prone to failure because of malpositioning and edge loading, which have been noted to be more common in dysplasia cases.
A 70-year-old man is scheduled to undergo bearing surface revision for wear and osteolysis 10 years after cementless total hip arthroplasty. The femoral head is 28 mm alumina-oxide ceramic material. The components are in good position, and there is no evidence of fixation loosening of either component by radiograph or preoperative bone scan. What outcome is associated with isolated polyethylene exchange?
Reduced risk for future wear and osteolysis with a larger femoral head
Reduced risk for future wear and osteolysis with a cobalt chrome femoral head
Similar risk for dislocation compared to primary total hip arthroplasty
Increased risk for dislocation compared to primary total hip arthroplasty Corrent answer: 4
The major complication associated with polyethylene exchange is postoperative dislocation. Maloney and associates noted a dislocation rate of 11% in a study of 35 hips after such revision. Boucher and associates reported a 25% rate of dislocation in a study of 25 patients. Larger femoral heads result in higher volumetric wear in contrast to smaller-diameter heads. Stem revision is not indicated because there is no fixation loosening. Moreover, stem biomaterial has no effect on polyethylene wear.
A healthy, active 68-year-old woman had a total hip arthroplasty 3 months ago. She has been to the emergency department with a posterior dislocation 3 times during the last 2 months. Plain radiographs and a CT scan confirm that the acetabular component is oriented in 5 degrees of retroversion and 55 degrees of abduction.
What is the most appropriate treatment?
Revision of the femoral and acetabular components
Maximizing head-neck ratio and increasing head length
Acetabular component revision
Closed reduction with an abduction brace and reinforcement of hip precautions
Acetabular malposition can lead to recurrent instability. When this cause is confirmed, reorientation of the component can lead to successful revision surgery. Revision of the femoral component may not be necessary if the acetabular component is repositioned. Increasing length and maximizing head-neck ratio cannot make up for component malposition. There is no role for nonsurgical treatment in the setting of recurrent instability with component malposition in an active, healthy patient.
A 55-year-old woman with history of HIV infection is scheduled for revision total knee arthroplasty to address instability. The index surgery was done 3 years ago. What is the white blood cell (WBC) count threshold in the synovial fluid for an infection diagnosis?

Question 85

Figures 11a and 11b show the T2-weighted MRI scans of the lumbar spine of a 53-year-old woman who has low back and right lower extremity pain. What structure is the arrow pointing to in Figure 11a? Review Topic

Explanation

The arrow is pointing to a cystic-appearing structure with high signal intensity on T2-weighted image sequencing. It appears to be contiguous with the hypertrophied right facet joint, which appears to also have high signal intensity. The mass significantly narrows the right lateral recess. The high signal intensity suggests that this is a fluid-filled mass. In addition, the facet joints are degenerative and there is a very mild degree of anterolisthesis on the sagittal image. These findings make a lumbar synovial cyst the most likely diagnosis. Most lumbar juxtafacet cysts are observed at the L4-5 level, extradurally and adjacent to the degenerative facet joint. They may contain synovial fluid and/or extruded synovium. Presentation is indistinguishable from that of a herniated disk. The etiology of spinal cysts remains unclear, but there appears to be a strong association between their formation and worsening spinal instability. They occasionally regress spontaneously and may respond to aspiration and injection of corticosteroids, though there is a high recurrence rate with nonsurgical management. Synovial cysts resistant to nonsurgical management should be treated surgically. If the patient’s symptoms can be attributable to radicular findings, a microsurgical decompression that limits further destabilization should suffice. However, if there is significant low back pain attributable to spinal instability, decompression and fusion remains an appropriate option.

Question 86

Figure 33 shows the MRI scan of a 55-year-old woman who has had a 6-week history of back and leg pain. Which of the following clinical scenarios is most consistent with the MRI scan findings at L4-L5? Review Topic

Explanation

The MRI scan reveals a L4-L5 foraminal disk herniation originating from the L4-5 disk space that has migrated up into the foramen, compressing the left L4 nerve root. There is normal distribution of the roots in the cerebrospinal fluid, excluding arachnoiditis as a diagnosis, and disk herniation in this location would not result in cauda equina syndrome or myelopathy.

Question 87

A 62-year-old active man returns for routine follow-up 16 years after hip replacement. He has no hip pain. Radiographs reveal a well-circumscribed osteolytic lesion around a single acetabular screw. All hip components are perfectly positioned. Comparison radiographs obtained 6 months later show an increase in the size of the osteolytic lesion. CT depicts a well-described lesion that is 3 cm at its largest diameter and is localized around one screw hole with an eccentric femoral head. What treatment is appropriate, assuming that well-fixed cementless total hip components are in place?

Explanation

DISCUSSION:
Given a well-fixed acetabular metal shell and a localized osteolytic lesion, good outcomes can be expected from liner revision in this clinical scenario with retention of the metal socket, assuming no damage to the components or other unexpected findings arise during revision surgery. Here, complete cup revision is not warranted, considering the appropriate implant position. Beaulé and associates reviewed 83 consecutive patients (90 hips) in whom a well-fixed acetabular component was retained in a clinical scenario such as the one described. No hip showed recurrence or expansion of periacetabular osteolytic lesions. If the metal cup is unstable, acetabular component revision may be indicated.

Question 88

A 72-year-old woman falls onto her left hip after tripping over a curb during her daily 3-mile walk. An injury radiograph is shown in Figure A. What is the best long term solution?

Explanation

THA is the best long term solution for displaced femoral neck fractures (FNF) in active elderly patients.
The aims of surgery for FNF in elderly patients are immediate pain relief, rapid mobilization, and low complications and revision. THA has best pain relief, fewer reoperations, best survivorship and is most cost-effective but has longer operative/anesthetic time, blood loss, higher infection rate, and potential instability compared with HA.
Healy and Iorio examined the optimal treatment for elderly FNF. They compared internal fixation (120 patients) with arthroplasty (HA, 43 patients; THA, 23 patients). There was no different in reoperation or mortality rates between the 2 groups, but arthroplasty was more cost effective, had independent living, and longer interval to reoperation/death. THA had less pain, better function, and lower rates of reoperation than HA, and was most cost-effective. They concluded that THA was the best treatment.
Yu et al. performed a meta-analysis of randomized controlled trials to determine whether THA or hemiarthroplasty (HA) was superior. They found that THA had lower risk of reoperation (RR = 0.53), higher risk of dislocation (RR = 1.99), and
higher functional scores at 1 and 4 years. There was no difference in mortality, infection and complication rates.
Figure A shows a displaced left femoral neck fracture. Incorrect Answers:

Question 89

A 65-year-old woman has significant neck pain after falling and striking her head. A radiograph and sagittal CT scan are shown in Figures 23a and 23b. What is the most likely diagnosis?

Explanation

DISCUSSION: The radiograph shows a displacement of C5 on C6 of approximately 25%. The CT scan shows a perched facet at C5-6. There is no evidence of a facet fracture. A bilateral facet dislocation would show a displacement of more than 50%.
REFERENCES: Rothman RH, Simeone FA (eds): The Spine, ed 4. Philadelphia PA, WB Saunders, 1999, pp 927-937.
Vaccaro AR, Betz RR, Zeidman SM (eds): Principles and Practice of Spine Surgery. St Louis, MO, Mosby, 2003, pp 455-458.

Question 90

A healthy 70-year-old man has a swollen knee after undergoing a knee replacement 10 years ago. Aspiration of the knee reveals cloudy, viscous synovial fluid. Laboratory studies show an erythrocyte sedimentation rate of 10 mm/h and a C-reactive protein level of less than 0.5. What is the most likely diagnosis?

Explanation

DISCUSSION: Polyethylene wear debris can result in significant synovitis and subsequent cloudy appearing synovial fluid. Typically, laboratory studies show a WBC of less than 30,000/mm³ and no left shift. Cytologic examination can reveal intra-articular polyethylene particles. Infected total knee arthroplasty is extremely uncommon in a healthy, immune-competent patient who has a normal preoperative erythrocyte sedimentation rate and C-reactive protein level.
REFERENCE: Barrack RL, Jennings RW, Wolfe MW, Bertot AJ: The value of preoperative aspiration before total knee revision. Clin Orthop 1997;345:8-16.

Question 91

Figure 19 shows the radiograph of a 45-year-old woman who has a painful nonunion. Treatment should consist of

Explanation

DISCUSSION: The radiograph reveals a reverse obliquely subtrochanteric/intertrochanteric fracture. Open reduction and internal fixation should be accomplished with a 95° fixed angle device. An intramedullary nail with screw fixation into the head is another possible technique. Either method should correct the varus deformity. Exchange of a high-angled screw and plate device to a longer side plate and bone grafting does not afford any improvement in the mechanical stability. Hardware removal and retrograde intramedullary nailing is not indicated for this level of a proximal femoral injury. Placement of an implantable bone stimulator may change local biologic factors but would not enhance mechanical stability. The patient’s femoral head is intact without signs of collapse; therefore, hardware removal, proximal femoral resection, and total hip arthroplasty are not warranted.
REFERENCES: Haidukewych GJ, Israel TA, Berry DJ: Reverse obliquity fractures of the intertrochanteric region of the femur. J Bone Joint Surg Am 2001;83:643-650.
Koval KJ, Zuckerman JD: Intertrochanteric fractures, in Rockwood & Green’s Fractures in Adults, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 1635-1681.

Question 92

A 28-year-old woman fell on her right wrist while rollerblading 2 days ago. She was seen in the emergency department at the time of injury and was told she had a sprain. Examination now reveals dorsal tenderness in the proximal wrist but no snuffbox or ulnar tenderness. Standard wrist radiographs are normal. What is the next most appropriate step in management?

Explanation

DISCUSSION: When considering the diagnosis of scapholunate ligament injury, standard radiographic views of the hand will not always reveal widening of the scapholunate gap. Although MRI may reveal injury to the ligaments, the PA clenched fist view can be obtained in the office during the initial patient visit. Arthroscopy is not a first-line diagnostic tool.
REFERENCES: Walsh JJ, Berger RA, Cooney WP: Current status of scapholunate interosseous ligament injuries. J Am Acad Orthop Surg 2002;10:32-42.
Browner BD, Levine AM, Jupiter JB, et al (eds): Skeletal Trauma, ed 2. Philadelphia, PA, WB Saunders, 1998, pp 1366-1367.

Question 93

A 47-year-old woman underwent a bunionectomy and hallux valgus correction a few years ago. She now has the complication shown in Figures 38a and 38b. She has no pain with motion of the metatarsophalangeal or interphalangeal joints. What is the best reconstructive option in this setting?

Explanation

DISCUSSION: The patient has a flexible hallux varus that is a complication of the bunion surgery. With joints that are not arthritic and still flexible, a medial release is necessary to realign the joint. The extensor hallucis longus split transfer helps maintain position and still preserve motion at the interphalangeal joint level. Arthrodesis is a salvage procedure. Soft-tissue releases alone are most likely inadequate. Excision of the lateral sesamoid is contraindicated because that further compromises the forces resisting hallux varus. Phalangeal osteotomy would not address the medial subluxation at the metatarsophalangeal joint.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 27-32.
Coughlin MJ, Mann RA, Saltzman CL (eds): Surgery of the Foot and Ankle, ed 8. Philadelphia, PA, Mosby, 2007, pp 345-351.

Question 94

The radiograph shown in Figure 50a and the CT scan shown in Figure 50b reveal a lesion in the left femoral neck of a 12-year-old boy who has pain in the left hip. The most likely cause of the osteopenia of the left proximal femur is

Explanation

Figure 50A: AP pelvis with a 1 cm lucency in the calcar region of the femoral neck and diffuse osteopenia of the proximal femur. Figure 50B: CT scan of the same patient showing a well demarcated lcm lesion in the femoral neck with an obvious nidus. Careful evaluation of the radiographs is critical in this question. First the obvious osteoid osteoma must be recognized. From there answers 2 and 3 can be eliminated. Neither radiograph reveals any sign that treatment has occurred, and the CT scan shows no signs of extensive involvement, thus answer 5 should also be eliminated. The real key is believing that such diffuse osteoporosis could occur in such a young child, as Jones described in his article from 1969.

Question 95

A patient who underwent total knee arthroplasty 6 years ago now reports knee pain for the past 3 days following dental surgery. Cultures of the aspirate are positive for Staphylococcus epidermidis. Management should consist of

Explanation

DISCUSSION: The patient has an early prosthesis infection as a result of hematogenous seeding from dental surgery. Irrigation and debridement with polyethylene exchange and IV antibiotics have been successful in early postoperative infections; it is less likely to be effective for a late hematogenous infection. Immediate total component exchange also may be effective, but it should be reserved for failure of irrigation and debridement.
REFERENCES: Pellicci PM, Tria AJ Jr, Garvin KL (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, pp 323-337.
Goldman RT, Scuderi GR, Insall JN: 2-stage reimplantation for infected total knee replacement. Clin Orthop 1996;331:118-124.

Question 96

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

Explanation

DISCUSSION: The popliteal tendon arises from the posterior aspect of the tibia and courses through the knee joint through the popliteus hiatus of the lateral meniscus before attaching on the lateral femur anterior to the lateral collateral ligament. It is the only tendon in the knee joint that can be viewed directly on arthroscopy.
REFERENCES: Kimura M, Shirakura K, Hasegawa A, Kobayashi Y, Udagawa E: Anatomy and pathophysiology of the popliteal tendon area in the lateral meniscus: 1. Arthroscopic and anatomical investigation. Arthroscopy 1992;8:419-423.
Arnoczky SP, Skyhar MJ, Wickiewicz TL: Basic science of the knee, in McGinty JB (ed): Operative Arthroscopy. New York, NY, Raven Press, 1991, pp 155-182.

Question 97

A 56-year-old woman has a painful mass on the bottom of her left foot, and orthotic management has failed to provide relief. Examination reveals that the mass is contiguous with the plantar fascia. An MRI scan shows a homogenous nodule within the plantar fascia. Resection of the tumor is shown in the clinical photograph in Figure 39. What type of cell is most likely responsible for the formation of this tumor?

Explanation

DISCUSSION: The history, examination, and surgical findings are most consistent with plantar fibromatosis. Plantar fibromatosis is a benign tumor of the plantar fascia that consists chiefly of fibromyoblasts. These cells produce excessive collagen and are similar to the cells found in the palmar fascia of patients with Dupuytren’s contracture of the hand. The myocyte, synovial cell, and osteocyte all produce their respective individual tissue types but do not contribute to the formation of a plantar fibromatosis. The T-cell is an important immunologic cell that is most affected in patients with HIV.
REFERENCE: Sammarco GJ, Mangone PG: Classification and treatment of plantar fibromatosis. Foot Ankle Int 2000;21:563-569.

Question 98

When placing a percutaneous retrograde pubic rami screw for fixation of an acetabular fracture, which of the following radiographic views can best ensure that the screw does not exit the posterior aspect of the superior pubic ramus?

Explanation

DISCUSSION: As reviewed in the referenced article by Starr et al, when placing a retrograde pubic rami screw, the pelvic inlet iliac oblique view will best determine the anteroposterior placement of the screw in the pubic ramus. To ensure placement outside of the joint, the outlet obturator oblique is best, but all other views should be incorporated into determination of the position of fixation, as the corridor for this screw placement is quite narrow.

Question 99

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

Explanation

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

Question 100

A B Figures 19a and 19b are the CT scans of an 18-year-old man who was a restrained driver in a rollover motor vehicle collision. What was the primary mechanism of injury?

Explanation

DISCUSSION
This injury pattern represents a flexion distraction injury, or a Chance fracture. The imaging hallmark of this injury is the axial split of the pedicle seen on the sagittal CT scan. This injury necessitates surgical intervention to prevent progressive deformity and pain. A rotation mechanism results in a dislocation with a rotational deformity at the level of injury. An extension force causes failure of the anterior column in tension with compression of the posterior column. An axial load force would result in a burst fracture.
RECOMMENDED READINGS
Bono CM, Rinaldi MD. Thoracolumbar trauma. In: Spivak JM, Connolly PJ, eds. Orthopaedic Knowledge Update: Spine 3. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2006:201-216.
Vaccaro AR, Baron EM, Sanfilippo J, Jacoby S, Steuve J, Grossman E, DiPaola M, Ranier P, Austin L, Ropiak R, Ciminello M, Okafor C, Eichenbaum M, Rapuri V, Smith E, Orozco F, Ugolini P, Fletcher M, Minnich J, Goldberg G, Wilsey J, Lee JY, Lim MR, Burns A, Marino R, DiPaola C, Zeiller L, Zeiler SC, Harrop J, Anderson DG, Albert TJ, Hilibrand AS. Reliability of a novel classification system for thoracolumbar injuries: the Thoracolumbar Injury Severity Score. Spine (Phila Pa 1976). 2006 May 15;31(11 Suppl):S62-9; discussion S104. PubMed PMID:16685239.View Abstract at PubMed

Full Question & Answer Text (for Search Engines)

Question 1:

-What is the etiology of this patient’s problem?

Options:

Ischemia
Overuse condition
Pathologic laxity
Increased humeral retroversion

Correct Answer: Overuse condition

Explanation:

DISCUSSION FOR QUESTIONS 78 THROUGH 80
Little leaguer’s shoulder is an overuse condition of the proximal humeral physis. Patients report diffuse pain that is worse with throwing. Factors that contribute to the condition include excessive throwing,improper throwing mechanics, and muscle-tendon imbalance. Radiographs usually show widening of the proximal humeral physis, and, in more severe cases, metaphyseal demineralization or fragmentation. Surgical fixation is not required for healing. Treatment involves rest until symptoms resolve, followed by initiation of an interval throwing program. Pitching coaches should evaluate throwing mechanics and maintain pitch counts. The dominant shoulders of throwing athletes undergo adaptive changes, resulting in increased external rotation and decreased internal rotation. These changes occur secondary to softtissue and bony adaptations, including increased humeral retroversion. Ischemia has been implicated as a potential cause of osteochondritis dissecans lesions. Rotator cuff tendonitis presents with anterolateral shoulder pain that is worse with activity. Pain is reproduced with resisted supraspinatus testing, and radiograph findings are typically normal.
Adolescent shoulder injuries are often caused by subtle, atraumatic instability most often sustained in sports with overhead movements, including baseball. These symptoms are more likely to occur in athletes with evidence of increased soft-tissue laxity.

Question 2:

Options:

0 to 15 degrees
20 to 30 degrees
40 to 90 degrees
100 to 120 degrees
130 to 140 degrees

Correct Answer: 40 to 90 degrees

Explanation:

Question 3:

Options:

Neurogenic claudication
Vascular claudication
Lumbar radiculopathy
Cervical myelopathy
Central cord syndrome

Correct Answer: Neurogenic claudication

Explanation:

Question 4:

What is the most common foot deformity associated with myelomeningocele?

Options:

Talipes equinovarus
Congenital vertical talus
Calcaneus valgus
Calcaneus varus
Cavus

Correct Answer: Talipes equinovarus

Explanation:

Question 5:

Options:

cast wedging in the outpatient clinic.
closed reduction under anesthesia and application of a new long leg cast.
reduction and placement of an intramedullary rod.
anatomic open reduction and compression plating with interfragmentary screws.
pins and plaster to maintain the reduction.

Correct Answer: cast wedging in the outpatient clinic.

Explanation:

Question 6:

In addition to the radiographic features seen in Figures 49a and 49b, this patient will most likely have which of the following findings?

Options:

Microcephaly
1,25 dihydroxy vitamin D deficiency
Normal dentition
Anemia
Developmental delays

Correct Answer: Anemia

Explanation:

Question 7:

Failure of posterolateral corner repair or reconstruction of the knee may be associated with which of the following? Review Topic

Options:

Valgus malalignment
Varus malalignment
Anterior cruciate ligament reconstruction
Posterior cruciate ligament reconstruction
Medial collateral ligament reconstruction

Correct Answer: Varus malalignment

Explanation:

Question 8:

Options:

obtain an emergent arteriogram.
obtain an emergent MRI scan.
perform a thorough examination of the knee ligaments.
perform surgical repair or bypass of the injured popliteal vessels.
perform surgical repair or bypass of the injured popliteal vessels and ligament reconstruction.

Correct Answer: perform surgical repair or bypass of the injured popliteal vessels.

Explanation:

Question 9:

98 degrees (range, 0 degrees to 9 degrees). In knees with varus joint lines

Options:

>4 degrees (normal = neutral), the posterior condylar angle was more internally rotated relative to the transepicondylar axis. Therefore, to prevent internal malalignment using standard components, the femoral component should be more externally rotated relative to the posterior condylar axis in this scenario.
Incorrect Answers:

Correct Answer: >4 degrees (normal = neutral), the posterior condylar angle was more internally rotated relative to the transepicondylar axis. Therefore, to prevent internal malalignment using standard components, the femoral component should be more externally rotated relative to the posterior condylar axis in this scenario.

Question 10:

-Which gene mutation is associated with the condition shown in Figures a and b?

Options:

Sonic Hedgehog
Collagen type I (COL1A2)
Neurofibromatosis 1 (NF1)
Low dietary intake of vitamin D
Fibroblast growth factor receptor 3 (FGFR3)

Correct Answer: Collagen type I (COL1A2)

Question 11:

- A 32-year-old has diffuse pain, weakness, and limited overhead motion in the shoulder as a result of falling on his outstretched arm 2 months ago. Examination reveals medial scapular winging, and an electromyogram shows denervation of the long thoracic nerve. Management should consist of

Options:

scapulothoracic fusion
strengthening of the periscapular muscles
pectoralis minor-fascia lata graft transfer to the scapula
pectoralis major-fascia lata graft transfer to the scapula
exploration of the long thoracic nerve, with sural nerve graft

Correct Answer: strengthening of the periscapular muscles

Explanation:

Question 12:

Options:

Diagnostic arthroscopy of the hip
Hip bone scan
Hip MRI arthrogram
Hip ultrasonography

Correct Answer: Hip MRI arthrogram

Explanation:

This clinical scenario describes a patient with FAI attributable to pincer (acetabular) deformity. This form of FAI, which involves prominence of the anterosuperior acetabular lip, may be more common among women. Decreased range of motion and pain occur secondary to the abutment of the femoral head against the acetabular labrum and rim. Hip flexion, combined with adduction and internal rotation, recreates this contact and causes pain, but CAM or pincer etiology remains unknown. The differential diagnosis of hip pain in a young athlete includes femoral neck stress reaction/fracture, sacroiliac arthritis, intra-articular loose body, trochanteric bursitis, osteitis pubis, and hernia. No information presented in this scenario suggests any of these causes. Diagnosis of FAI is best performed via MR imaging, with an arthrogram increasing the sensitivity and specificity for labral pathology. Ultrasonography may be useful in the diagnosis of dysplasia or for dynamic assessment of a snapping hip, but ultrasonography is not commonly
used to diagnose labral pathology. Although concomitant chondral lesions of the femoral head are uncommon, the forced leverage of the anterosuperior femoral neck upon the anterior acetabulum may result in a “contra-coup” chondral injury on the posteroinferior acetabulum. This is the most common location of chondral lesions in this scenario. Without bony resection to prevent further impingement, this patient will continue to experience symptoms. Because there is no evidence of femoral neck prominence (CAM lesion), there is no indication for osteoplasty of the femoral neck; resection of the pincer lesion is necessary. This will often require take-down of the labrum in this location. If possible, iatrogenic or traumatic labral tears should subsequently be repaired after pincer debridement because the labrum has
important functions for hip stability and maintenance of the suction seal of the joint.

Question 13:

Which of the following infectious organisms may be associated with underlying malignancy?

Options:

Acinetobacter species
Clostridium septicum
Peptostreptococcus
Proteus mirabilis
Pseudomonas mendocina

Correct Answer: Clostridium septicum

Explanation:

Question 14:

What is the effect on knee kinematics following placement of an anterior cruciate ligament (ACL) graft at the 12 o’clock position?

Options:

Decreased rotational stability
Decreased anterior-posterior stability
Decreased flexion
Decreased extension
Graft failure secondary to impingement

Correct Answer: Decreased rotational stability

Explanation:

Question 15:

Options:

Observation with a high expectation for recovery
Observation for 1 week, followed by exploration if recovery is not evident
Immediate exploration of the radial nerve and fracture fixation
Immediate exploration of the radial nerve without fracture fixation
Removal of the coaptation splint and repeat reduction

Correct Answer: Observation with a high expectation for recovery

Explanation:

Question 16:

Options:

physical therapy.
doxycycline.
ciprofloxacin.
nonsteroidal anti-inflammatory drugs.
gentamicin.

Correct Answer: doxycycline.

Explanation:

Question 17:

Options:

Protect the airway and use smelling salts
Protect the airway, move to the shade, and place in reverse Trendelenburg
Protect the airway and protect from seizure activity
Protect the airway, start CPR, and prepare to cardiovert
Protect the airway, and move patient slowly to a spine board

Correct Answer: Protect the airway, start CPR, and prepare to cardiovert

Explanation:

Question 18:

Nonsurgical management of pectoralis major tears is likely to result in weakness of glenohumeral Review Topic

Options:

abduction and external rotation.
abduction and internal rotation.
adduction and external rotation.
adduction and internal rotation.
external rotation and forward flexion.

Correct Answer: adduction and internal rotation.

Explanation:

Question 19:

Options:

He may wrestle if his lesions are covered.
He may wrestle if he is on oral antiviral agents for 48 hours.
He may wrestle immediately with no other treatment.
He cannot wrestle until the lesions are scabbed over and there are no new lesions for at least 72 hours.
He cannot wrestle for 2 weeks.

Correct Answer: He cannot wrestle until the lesions are scabbed over and there are no new lesions for at least 72 hours.

Explanation:

Question 20:

50%

Options:

greater than 50%
None, by 5 years the allograft cartilage will be completely acellular

Correct Answer: greater than 50%

Explanation:

By 5 years, the allograft cartilage will be completely acellular, so there will be no residual donor chondrocytes.
Enneking et al. conducted both radiographic and histologic studies of sixteen massive retrieved human allografts four to sixty-five months after implantation. Analysis of the articular cartilage revealed no evidence that any chondrocytes had survived, even when the graft had been cryoprotected before it was preserved by freezing.
A 64-year-old woman with a longstanding history of rheumatoid arthritis complains of finger dysfunction for the past 6 months. Figure A displays her hand during active extension of all fingers. Figure B displays her hand maintaining her fingers extended following passive extension. What is the next most appropriate treatment for the ring finger?
Spiral oblique retinacular ligament reconstruction
Sagittal band reconstruction
Lateral band reconstruction
Central slip reconstruction
Triangular ligament and transverse retinacular ligament reconstruction
Sagittal band disruption is often associated with rheumatoid arthritis. When this patient attempts to actively extend the affected digit, the extensor tendon
subluxates ulnarly as a result of the sagittal band rupture, and is left with an extensor lag. If one passively extends the finger fully, the patient is able to maintain this position, as the tendon is intact.
Sagittal band reconstruction can be performed with Watson's technique of creating a distally based tendon graft harvested from the central third of the extensor tendon, passed deep to the intermetacarpal ligament and sutured back to itself. Illustration A depicts an intraoperative view of the tendon before reconstruction and Illustration B displays tendon following sagittal band reconstruction. Illustration C displays all of the anatomic locations
of the options listed above.
A splenectomy is performed in a 7-year-old boy following a motor vehicle accident. All of the following are recommended for long-term management EXCEPT:
Pneumococcal vaccination
Haemophilus influenza type B vaccination
Meningococcal group C vaccination
Lifelong prophylactic antibiotics
Hepatitis A vaccination
All of the responses are correct except the need for Hepatitis A vaccine. Hepatitis A is a virus with tropism for hepatocytes which causes infection from fecal-oral contaminated food/water, and shows no increased rate of either infectivity or morbidity in patients with hyposplenism.
Basic recommendations for splenectomized patients include:
All splenectomized patients and those with functional hyposplenism should receive pneumococcal immunization.
Patients not previously immunized should receive haemophilus influenza type B vaccine.
Patients not previously immunized should receive meningococcal group C conjugate vaccine.
Influenza immunization should be given.
Lifelong prophylactic antibiotics are still recommended (oral phenoxymethylpenicillin or erythromycin). This is seemingly despite lack of good data demonstrating a role for lifelong chemoprophylaxis and the acknowledgement that long-term compliance may be problematic.
Davies et al review the current level of evidence supporting these guidelines
for infection prevention in patients with hyposplenism. New to these guidelines are issues regarding occupational exposure and the use of the meningococcal group C and the seven-valent pneumococcal vaccine in non-immunized hyposplenic patients.
Gandhi et al evaluated their nonoperative management of blunt splenic injury in pediatric trauma care. They found compared to historical controls, children with blunt splenic injuries who were hemodynamically stable could be safely monitored with a protocol which required 4 days of inpatient care, 3 weeks of quiet home activities, and 3 months of light activity. This protocol seems to allow for safe return to unrestricted activity.
Incorrect Answer:
Ligaments attach to bone by both direct insertion and indirect insertion. Which of the following most accurately describes the order of the four transition zones of direct insertion?
Ligament > fibrocartilage > mineralized fibrocartilage > bone
Ligament > mineralized fibrocartilage > fibrocartilage > bone
Ligament > mineralized fibrocartilage > periosteum > bone
Ligament > Sharpey's fiber > periosteum > bone
Ligament > periosteum > fibrocartilage > bone
There are two types of tendon/ligament insertion into bone: direct and indirect insertion. The more common, indirect insertion, occurs when the superficial ligament fibers insert into the periosteum. Direct insertion of tendon/ligaments
into bone occurs through a transition of 4 distinct phases: 1) ligament, 2) fibrocartilage, 3) mineralized fibrocartilage, and 4) bone.
While flexing the elbow to perform a biceps curl, what type of muscle contraction is occuring?
Isometric
Isokinetic
Plyometric
Eccentric
Concentric
Concentric muscle contractions occur when a muscle shortens during contraction, as in the upward motion when performing a biceps curl. An eccentric contraction occurs when a muscle lengthens with contraction, as in the "negative" or lowering motion of a biceps curl. An example of an isometric (muscle contracts while maintaining constant length) contraction would be pushing against an immovable object. An example of an isokinetic (muscle has constant speed of contraction) occurs with specialized equipment like Cybex machines. Plyometric contractions occur when a muscle rapidly lengthens just prior to contraction - like during repetitive box jumping.
Woo and Buckwalter describe the mechanisms, barriers, and molecular processes involved in ligament and tendon injury and repair.
A 34-year-old laborer has her left foot crushed in a piece of farming equipment as shown in Figure A. All of the following are reasons for a poor outcome following a crush injury to the foot EXCEPT:
Workers compensation injury
Development of reflex sympathetic dystrophy (complex regional pain syndrome)
Delayed soft-tissue coverage in mangled extremities
Immediate skeletal stabilization
Ongoing litigation
This patient has a mangled extremity. Rigid skeletal stabilization is recommended to enhance soft-tissue healing.
Level 4 evidence from Myerson et al found that delayed soft-tissue coverage in mangled extremities correlated with poor outcome. Poor results also occurred
if treatment was not immediately initiated (immediate debridement shown in Illustration A), if patients subsequently had neuritis or reflex sympathetic dystrophy, or if patients were involved in ongoing workers' compensation and litigation. Neuroischemia following substantial soft-tissue injury likely plays a role in the development of chronic pain after crush injuries to the foot, either through direct trauma to the peripheral nerves or by intraneural or extraneural fibrosis. This trauma to the nerve may cause chronic neuritis, which then triggers a sympathetically mediated reflex sympathetic dystrophy (complex regional pain syndrome).
A 65-year-old man undergoes total knee replacement and is found to have deep vein thrombosis two days later. What molecule is
thought to be involved in this process when it is released during surgical dissection?
Prothrombin
RANKL
IL-1b
Thromboplastin
Factor XI
Corrent answer: 4
Thromboplastin is also known more commonly as Tissue Factor (TF), which is involved in the Extrinsic Pathology of the coagulation cascade.
During surgical dissection, insults occur to the endothelial walls of blood vessels. There are three ways in which the body reacts to form a clot so that the patient does not bleed excessively. One is via vessel contraction, another is by collagen release, and a third is by tissue thromboplastin release. Thromboplastin release is part of the extrinsic coagulation pathway (see
Illustration A). Thromboplastin release activates Factor VII which activates Factor X which converts prothrombin to thrombin. Thrombin is the catalyst for converting fibrinogen to fibrin which induces clot formation. While this is useful for decreasing bleeding, it is the same mechanism by which a deep venous thrombosis (DVT) develops.
Which of the following materials has a Young's modulus of elasticity that is most similar to cortical bone
Titanium
Zirconia
Stainless steel
Ceramic (Al2O3)
Alloy (Co-Cr-Mo)
Of the materials listed Titanium has an elastic moduli closest to cortical bone. Titanium is extra-ordinarily light, strong, highly ductile, and corrosion resistant. Titanium is however very notch sensitive and has poor wear resistance.
Young Modulus of Elasticity is defined as the stiffness (ability to maintain
shape under external loading) of a material. On the stress vs. strain curve it is defined as the slope of the line in the elastic zone (see Illustration A). Young’s modulus is constant and different for each material. The relevant moduli (unit GPa) are approximated below:

Question 21:

A patient undergoes hip arthroscopy, and the pathology is seen in Figure 18. What is the most likely diagnosis?

Options:

Femoral head articular defect
Acetabular articular defect
Haversian fat pad hypertrophy
Labral tear
Loose body

Correct Answer: Labral tear

Explanation:

Question 22:

Options:

UCL repair and nighttime elbow extension splinting
UCL repair with ulnar nerve decompression in situ
Allograft UCL reconstruction with interference screws
Autograft UCL reconstruction with ulnar nerve transposition
Autograft UCL reconstruction using a docking technique

Correct Answer: Autograft UCL reconstruction with ulnar nerve transposition

Explanation:

Question 23:

Options:

(11; 22) (q24; q12)
(X; 18) (p11; q11)
(12; 22) (q13; q12)
(2; 13) (q35; q14)
(12; 16) (q13; p11)

Correct Answer: (11; 22) (q24; q12)

Explanation:

DISCUSSION: The imaging studies show a permeative lytic destructive lesion in the proximal radius with “hair-on-end” periosteal reaction and a large soft-tissue mass most consistent with Ewing’s sarcoma. The pathology reveals monotonous sheets of “round blue” cells. This limits the differential diagnosis to primary lymphoma of bone versus Ewing’s sarcoma. These are best differentiated by immunohistochemistry, cytogenetics, and flow cytometry. Lymphoma of bone is typically CD34 positive and CD99 negative; whereas, the reverse is true of Ewing’s sarcoma, CD34 negative and CD99 positive. The most common cytogenetic translocation with Ewing’s sarcoma is 11; 22; 21; 22 and 7; 22 translocations have also been reported in Ewing’s sarcomas. The X; 18 translocation is most commonly associated with synovial cell sarcomas; the 12; 22 translocation is most commonly associated with clear cell sarcomas; the 2; 13 translocation is most commonly associated with alveolar rhabdomyosarcomas, and the 12; 16 translocation is most commonly associated with myxoid liposarcomas. Flow cytometry is used to characterize the cell types of lymphomas.
REFERENCES: Womer R: The cellular biology of bone tumors. Clin Orthop Relat Res 1991;262:12-21.
Yamaguchi U, Hasegawa T, Morimoto Y, et al: A practical approach to the clinical diagnosis of Ewing’s sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue. J Clin Pathol 2005;58:1051-1056.
Lazar A, Abruzzo LV, Pollock RE, et al: Molecular diagnosis of sarcomas: Chromosomal translocations in sarcomas. Arch Path Lab Med 2006;130:1199-1207.

Question 24:

Options:

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

Correct Answer: Total knee replacement

Explanation:

Question 25:

Options:

Stretching the posterior capsule and pectoralis minor tendon
Stretching the posterior capsule and strengthening the subscapularis
Stretching the posterior capsule and using shoulder plyometrics
Stretching the anterior capsule and strengthening all components of the rotator cuff
Stretching the anterior capsule and improving pitching mechanics

Correct Answer: Stretching the posterior capsule and pectoralis minor tendon

Explanation:

Question 26:

Options:

Reticulosarcoma
Squamous cell carcinoma
Fibrosarcoma
Malignant fibrous histiocytoma

Correct Answer: Squamous cell carcinoma

Explanation:

Question 27:

Which of the following conditions is most commonly associated with the congenital hand problem shown in Figure 33?

Options:

Clubfeet
Thrombocytopenia
Congenital scoliosis
Ventricular septal defect
Arnold-Chiari malformation

Correct Answer: Clubfeet

Explanation:

Question 28:

The radiographic feature seen in Figure 37 that best indicates a slow-growing process is the

Options:

deformity of the fibula.
wide base of the lesion.
lack of joint deformity.
medullary canal extending into the lesion.
lack of periosteal reaction.

Correct Answer: deformity of the fibula.

Explanation:

Question 29:

Options:

Home exercise program
Sling at all times until her pain decreases
Closed manipulation under anesthesia
Arthroscopic rotator cuff repair
Arthroscopic anterior and posterior capsular release

Correct Answer: Home exercise program

Explanation:

Question 30:

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

Options:

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

Correct Answer: Lateral antebrachial cutaneous neuritis

Explanation:

Question 31:

What mechanism is associated with the spontaneous resorption of herniated nucleus pulposus?

Options:

Macrophage infiltration and phagocytosis
Granuloma formation
Antibody mediated destruction
Complement cascade activation
Major histocompatibility complex mediated pathways

Correct Answer: Macrophage infiltration and phagocytosis

Explanation:

Question 32:

Which of the following drawbacks is associated with the Ganz periacetabular osteotomy?

Options:

The tendency to anterior displacement of the hip joint
The need for two incisions
Limited potential for acetabular reorientation
Posterior column disruption
Devascularization of the acetabulum

Correct Answer: The tendency to anterior displacement of the hip joint

Explanation:

Question 33:

Which of the following is most important to acheive a good outcome following a Syme amputation?

Options:

trimming any dog ears
a viable and stable heel pad
achilles tendon lengthening
preserving the malleoli
tenodesing the extensor digitorum longus to the tibial shaft

Correct Answer: trimming any dog ears

Explanation:

Question 34:

Options:

Increase risk for iatrogenic ulnar nerve injury
Provide more construct stiffness than adding a medial pin
Improve construct stiffness in the presence of medial column comminution
Will not affect construct stiffness in the presence of residual distal fragment internal rotation

Correct Answer: Improve construct stiffness in the presence of medial column comminution

Explanation:

Question 35:

Options:

a spinal cord injury and he cannot participate in contact sports.
no obvious injury and can return to all sports without risk of recurrence.
no obvious injury, but he is at a high risk for breaking his neck in athletic competition.
transient quadriplegia only, but this places him at greater risk for future spinal cord injury and he should refrain from all contact sports.
transient quadriplegia and that there is no evidence of increased risk of permanent spinal cord injury should he return to contact sports.

Correct Answer: transient quadriplegia and that there is no evidence of increased risk of permanent spinal cord injury should he return to contact sports.

Explanation:

DISCUSSION: The long-term effect of transient quadriplegia is unknown. Based on a history of one brief episode of transient quadriplegia and normal examination and MRI findings, the risk of permanent spinal cord injury with a return to play is low. There is a risk of recurrent episodes of transient quadriplegia after the initial episode.
REFERENCES: Morganti C, Sweeney CA, Albanese SA, et al: Return to play after cervical spine injury. Spine 2001;26:1131-1136.
Odor JM, Watkins RG, Dillin WH, et al: Incidence of cervical spinal stenosis in professional and rookie football players. Am J Sports Med 1990;18:507-509.
Torg JS, Naranja RJ Jr, Palov H, et al: The relationship of developmental narrowing of the cervical spinal canal to reversible and irreversible injury of the cervical spinal cord in football players. J Bone Joint Surg Am 1996;78:1308-1314.
Vaccaro
AR
, Watkins B, Albert TJ, et al: Cervical spine injuries in athletes: Current return-to-play criteria. Orthopedics 2001;24:699-703.

Question 36:

Options:

Knee aspiration for culture
CT of the knee to assess implant rotation
Indium-111 leukocyte/technetium-99m sulfur colloid scan of the knee
Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) laboratory studies

Correct Answer: Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) laboratory studies

Explanation:

Question 37:

Options:

Arthroscopic Bankart surgery
Bony glenoid augmentation procedure
Subscapularis advancement
Open capsular shift
Hemiarthroplasty

Correct Answer: Bony glenoid augmentation procedure

Explanation:

Question 38:

Options:

oral antibiotics.
IV antibiotics.
surgical drainage of the perivertebral abscess and IV antibiotics.
bed rest.
cast immobilization.

Correct Answer: IV antibiotics.

Explanation:

DISCUSSION: The patient has diskitis. Administration of IV antibiotics speeds resolution and minimizes recurrence. Bed rest and cast immobilization have been successfully used to treat this disorder but can be associated with prolonged recovery and frequent recurrence, even when oral antibiotics are administered. A perivertebral abscess seen in association with this condition usually resolves without surgery.
REFERENCES: Ring D, Johnston CE II, Wenger DR: Pyogenic infectious spondylitis in children: The convergence of discitis and vertebral osteomyelitis. J Pediatr Orthop
1995;15:652-660.
Crawford AH, Kucharzyk DW, Ruda R, et al: Diskitis in children. Clin Orthop 1991;266:70-79.

Question 39:

Options:

Cortisone injection
Open surgical debridement
Immediate arthroscopic lavage
Intravenous vancomycin for presumptive MRSA infection
Obtain sexual activity history and select appropriate antibiotic

Correct Answer: Obtain sexual activity history and select appropriate antibiotic

Explanation:

Question 40:

Options:

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

Correct Answer: Conversion to a reverse shoulder arthroplasty

Explanation:

Question 41:

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

Options:

Lower cervical spine
Midthoracic spine
Thoracolumbar junction
Midlumbar spine
Lumbosacral junction

Correct Answer: Midlumbar spine

Explanation:

Question 42:

Options:

resectional arthroplasty.
metatarsophalangeal joint arthrodesis.
dorsal closing wedge osteotomy.
physical therapy.
a rigid steel shank shoe with a rocker bottom sole.

Correct Answer: a rigid steel shank shoe with a rocker bottom sole.

Explanation:

Question 43:

- A form of renal osteodystrophy that is characterized by pure osteomalacia is caused by

Options:

Secondary hyperparathyroidism
Phosphate retention secondary to uremia
Insufficient renal synthesis of 1, 25 dihydroxy vitamin D
Aluminum deposition in bone from oral phosphate binders
Persistent acidosis aggravating the negative calcium balance

Correct Answer: Aluminum deposition in bone from oral phosphate binders

Explanation:

Question 44:

Options:

Intramedullary nailing is associated with an increased risk of iatrogenic comminution.
There is a lower risk of iatrogenic radial nerve palsy with anterograde intramedullary nailing when compared to compression plating.
There is a lower risk of nonunion with antegrade intramedullary nailing when compared to compression plating.
The musculocutaneous nerve is at risk with lateral to medial distal locking screw placement
There is a higher risk of shoulder impingement with antegrade nailing compared to compression plating.

Correct Answer: The musculocutaneous nerve is at risk with lateral to medial distal locking screw placement

Explanation:

Question 45:

Options:

Eye patch and ophthalmology evaluation in 2 days
Fluorescein eye stain
Emergent CT
High-dose systemic steroids
Observation

Correct Answer: Emergent CT

Explanation:

Question 46:

Options:

Patella infera (baja)
Patella alta
Recurrence of medial joint overload
Nonunion of the osteotomy

Correct Answer: Patella infera (baja)

Explanation:

Question 47:

Options:

Revision ACL with bone-patellar tendon-bone (BTB) allograft and meniscal transplant
Distal femoral osteotomy
Pure sagittal osteotomy
Closing wedge and slope neutralizing high-tibial osteoto

Correct Answer: Closing wedge and slope neutralizing high-tibial osteoto

Explanation:

Lateral closing wedge (LCW) and medial opening wedge (MOW) high-tibial osteotomies (HTOs) can both correct varus knee alignment and stabilize the ACL–deficient knee. Increasingly, HTO is being proposed as a singular or concomitant procedure with ACL reconstruction for restoring knee stability and as a more reliable slope correction. LCW HTO demonstrates more reliable slope correction than does MOW HTO. Revision ACL with BTB allograft and meniscal transplant will not help early arthritis in varus alignment. Distal femoral osteotomy is usually considered for valgus knee. Pure sagittal osteotomy
would not help the patient’s medial knee pain, arthritis, and malalignment.

Question 48:

Options:

hemivertebra excision.
anterior and posterior spinal fusion with instrumentation from T4 to L4.
convex anterior hemiepiphyseodesis.
convex posterior hemiarthrodesis.
an orthosis.

Correct Answer: hemivertebra excision.

Explanation:

Question 49:

Which of the following patients is considered the most appropriate candidate for selective dorsal rhizotomy?

Options:

Nonambulatory 2-year-old with spastic diplegia
Nonambulatory 2-year-old with spastic quadriplegia
Nonambulatory 12-year-old with spastic quadriplegia
Ambulatory 4-year-old with spastic diplegia
Ambulatory 9-year-old with hemiplegia and athetosis

Correct Answer: Ambulatory 4-year-old with spastic diplegia

Explanation:

Question 50:

In the initial evaluation of acute low back pain (duration of less than 4 weeks), plain radiographs are recommended in which of the following situations?

Options:

Prolonged use of steroids
Prolonged use of nonsteroidal anti-inflammatory drugs
History of back pain as a child
Family history of back pain
Recent viral infection

Correct Answer: Prolonged use of steroids

Explanation:

Question 51:

A 2-year-old girl was born with the toe deformity shown in Figure 2. She has difficulty wearing shoes despite having adequate room in the toe box. Management at this time should consist of

Options:

stretching exercises, followed by taping of the toes in a derotational maneuver.
lengthening of the extensor digitorum longus tendon of the second toe and release of the metatarsophalangeal joint dorsal capsule.
resection arthroplasty of the proximal interphalangeal joint of the third toe, with release of the volar plate.
tenotomy of the flexor digitorum longus and brevis of the third toe.
a Girdlestone-Taylor transfer of the flexor digitorum longus to the extensor digitorum longus of the third toe.

Correct Answer: tenotomy of the flexor digitorum longus and brevis of the third toe.

Explanation:

Question 52:

Figures 20a and 20b are the radiographs of a 19-year-old woman who was involved in a motor vehicle accident. What mechanism of injury is most consistent with the injury?

Options:

Vertical shear
External rotation
Sagittal translation
Lateral compression
Anterior posterior compression

Correct Answer: Lateral compression

Explanation:

Question 53:

What is the most common complaint in patients with a developmental radial head dislocation?

Options:

Pain
Recurrent elbow subluxation
Limitation of extension
Cosmetic deformity
Locking

Correct Answer: Cosmetic deformity

Explanation:

DISCUSSION: Developmental dislocation of the radial head most frequently presents as a painless mass over the posterior aspect of the elbow. Patients do not have feelings of elbow subluxation but may report pain or clicking. Limitation of motion is most frequently found in the pronation and supination arc rather than in flexion and extension.
REFERENCES: Lloyd-Roberts GC, Bucknill TM: Anterior dislocation of the radial head in children-etiology: Natural history and management. J Bone Joint Surg Am 1977;58:402.
Hamilton W, Parks JC II: Isolated dislocation of the radial head without fracture of the ulna. Clin Orthop Relat Res 1973;97:94-96.

Question 54:

Patients who have osteonecrosis of the humeral head and who have the best prognosis are those with which of the following conditions?

Options:

Sickle cell disease
Associated malunion
Alcoholic-induced disease
Previously received high-dose steroids
Postradiation necrosis

Correct Answer: Sickle cell disease

Explanation:

DISCUSSION: The natural history of nontraumatic osteonecrosis varies greatly, so it is difficult to predict which patients will have severe arthrosis develop. Patients with sickle cell disease tend to have the most benign course. The most commonly reported cause of nontraumatic osteonecrosis is corticosteroid therapy. Fortunately, the incidence of osteonecrosis among patients treated with long-term systemic corticosteroids has fallen from more than 25% to less than 5% in recent years, owning to judicious steroid use and dosing. The interval between corticosteroid administration and the onset of shoulder symptoms is also variable, ranging from 6 to 18 months in one large series. This is comparable to the interval leading up to the onset of hip symptoms, which ranges from 6 months to 3 years or longer. The incidence of humeral head involvement has not been shown to vary with the underlying indication for steroid use.
REFERENCES: Hasan SS, Romeo AA: Nontraumatic osteonecrosis of the humeral head.
J Shoulder Elbow Surg 2002;11:281-298.
Mansat P, Huser L, Mansat M, et al: Shoulder arthroplasty for atraumatic avascular necrosis of the humeral head: Nineteen shoulders followed up for a mean of seven years. J Shoulder Elbow Surg 2005;14:114-120.

Question 55:

Which of the following methods accurately describes the measurement of tip-apex-distance as it relates to placement of a lag screw in the femoral head?

Options:

Summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs
Distance from the acetabular teardrop to the tip of the screw on an AP radiograph of the hip
Multiplication of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs
Distance from the center of the lesser trochanter to the tip of the screw on an AP hip radiograph
Summation of the distance between the tip of the greater trochanter and end of the screw on AP and lateral hip radiographs

Correct Answer: Summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs

Explanation:

Question 56:

Options:

Blood loss
Airway obstruction
Cerebrovascular accident
Periodontal disease
Hearing loss

Correct Answer: Airway obstruction

Explanation:

Question 57:

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

Options:

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

Correct Answer: Fracture of the anterior colliculus

Explanation:

Question 58:

A 5-year-old boy has had midfoot pain with activity for the past 3 months. He has no pain at rest. Radiographs are shown in Figures 29a and 29b. Management should consist of

Options:

a vascularized pedicle bone graft.
a short leg walking cast.
a custom-molded orthotic.
surgical debridement followed by antibiotics.
a bone stimulator.

Correct Answer: a short leg walking cast.

Explanation:

Question 59:

Options:

application of a compressive soft dressing, and aggressive edema control and range-of-motion exercises.
plaster immobilization without reduction of the fractures.
closed reduction and plaster immobilization.
surgical fixation of the middle finger metacarpal and closed treatment of the ring and little finger metacarpals.
surgical fixation of all three metacarpal fractures.

Correct Answer: surgical fixation of all three metacarpal fractures.

Explanation:

DISCUSSION: While most isolated metacarpal fractures can be treated nonsurgically, multiple metacarpal fractures are inherently unstable due to the loss of support that an intact adjacent metacarpal provides; therefore, treatment should consist of surgical fixation of all three metacarpal fractures.
REFERENCES: Stern PJ: Fractures of the metacarpals and phalanges, in Green DP, Hotchkiss RN, Pederson WC, et al (eds): Green’s Operative Hand Surgery, ed 5. Philadelphia, PA, Elsevier, 2005, p 286.
Faraj AA, Davis TR: Percutaneous intramedullary fixation of metacarpal shaft fractures. J Hand Surg Br 1999;24:76-79.

Question 60:

Which of the following is considered an advantage of arthroscopic distal clavicle excision compared with open distal clavicle excision?

Options:

Fewer complications
Lower infection rate
Evaluation of the glenohumeral joint
Preservation of the inferior acromioclavicular ligament
Decreased surgical time

Correct Answer: Evaluation of the glenohumeral joint

Explanation:

Question 61:

What is the most common complication associated with scalene regional anesthesia for shoulder procedures?

Options:

Cardiovascular collapse
Block failure
Seizure secondary to intravascular injection
Phrenic nerve injury
Laryngeal nerve injury

Correct Answer: Block failure

Explanation:

Question 62:

Options:

Infection
Osteosarcoma
Osteoblastoma
Giant cell tumor
Distal femoral fracture

Correct Answer: Osteosarcoma

Explanation:

Question 63:

Options:

Six weeks of acetylsalicylic acid postsurgically beginning the evening of surgery
Six weeks of low-molecular-weight heparin beginning the morning after surgery
Routine duplex scans of both lower extremities before hospital discharge to ensure the patient has not developed another DVT
Use of pneumatic calf compressors on both lower extremities while in the hospital and 4 weeks of warfarin starting the evening of surgery

Correct Answer: Use of pneumatic calf compressors on both lower extremities while in the hospital and 4 weeks of warfarin starting the evening of surgery

Explanation:

The 2011 AAOS guideline,
Preventing Venous Thromboembolic Disease in Patients Undergoing Elective Hip and Knee Arthroplasty
, recommends the combined use of mechanical and pharmacological prophylaxis in patients who have a history of previous thromboembolism. This recommendation is a consensus opinion of the work group that established these guidelines because there is no other reliable evidence for this clinical scenario. There is strong evidence against the use of routine duplex scans in patients undergoing hip and knee replacement. The remaining two responses are less appropriate because they do not include the use of mechanical prophylaxis immediately after surgery.

Question 64:

Options:

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

Correct Answer: Dega iliac

Question 65:

Options:

direct posterior.
direct lateral.
posterolateral.
posteromedial.

Correct Answer: posteromedial.

Explanation:

Question 66:

Options:

Posterior wall/ posterior column
Transverse
T-Type
Anterior column/ posterior hemitransverse
Both columns

Correct Answer: Posterior wall/ posterior column

Explanation:

Question 67:

Examination of a 10-year-old girl with a hypoplastic breast and atrophic pectoralis major may also reveal which of the following findings?

Options:

Absent middle phalanx
Absent deltoid muscle
Absent radius
Contralateral hypoplastic thumb
Clubfoot deformity

Correct Answer: Absent middle phalanx

Explanation:

Question 68:

Which nerve root contributes to both the sciatic and femoral nerves?

Options:

Correct Answer: L4

Explanation:

Question 69:

Options:

tighten as the knee extends past 10° of flexion.
tighten as the knee flexes past 90°.
loosen as the knee extends past 10° of flexion.
loosen as the knee flexes past 30°.
loosen as the knee flexes past 90°.

Correct Answer: tighten as the knee flexes past 90°.

Explanation:

Question 70:

Rupture of the structure shown in the axial cross and the sagittal sections in Figures 100a and 100b causes weakness in

Options:

extension and supination.
pronation.
flexion and pronation.
flexion and supination.

Correct Answer: flexion and supination.

Explanation:

DISCUSSION
87
The structure identified is the distal biceps tendon. Rupture of this tendon causes weakness in both flexion and supination. The biceps tendon does not affect extension or pronation.
RECOMMENDED READINGS
Baker BE, Bierwagen D. Rupture of the distal tendon of the biceps brachii. Operative versus non-operative treatment. J Bone Joint Surg Am. 1985 Mar;67(3):414-7. PubMed PMID: 3972865.
View Abstract at PubMed
Mazzocca AD, Spang JT, Arciero RA. Distal biceps rupture. Orthop Clin North Am. 2008 Apr;39(2):237-49, vii. doi: 10.1016/j.ocl.2008.01.001. Review. PubMed PMID: 18374814.
View Abstract at PubMed

Question 71:

Options:

biopsy of the tarsal navicular.
curettage and bone grafting of the tarsal navicular.
CBC count, C-reactive protein level, erythrocyte sedimentation rate, blood cultures, and IV antibiotics.
symptomatic treatment with restriction of weight bearing or application of short leg cast.
medial column lengthening of the foot through the tarsal navicular.

Correct Answer: symptomatic treatment with restriction of weight bearing or application of short leg cast.

Explanation:

DISCUSSION: The child has the classic findings of Kohler’s disease or osteochondrosis of the tarsal navicular. The cause of this condition is not known, but osteonecrosis and mechanical compression have been proposed. Children generally report midfoot pain over the tarsal navicular and limping. Physical findings include tenderness, swelling, and occasionally redness in the region of the tarsal navicular. Radiographs show sclerosis and narrowing of the tarsal navicular. The natural history of the condition is spontaneous resolution and reconstitution of the navicular. Symptomatic treatment with restriction of weight bearing or casting is recommended.
REFERENCES: Karp M: Kohler’s disease of the tarsal scaphoid. J Bone Joint Surg
1937;19:84-96.
Borges JL, Guille JT, Bowen JR: Kohler’s bone disease of the tarsal navicular. J Pediatr Orthop 1995;15:596-598.

Question 72:

Options:

Normal shoulder strength and function
Local sensory deficits
Fracture union
Infection
Malunion

Correct Answer: Malunion

Explanation:

Question 73:

A player on a professional football team sustains a knee injury and is diagnosed with an anterior cruciate ligament rupture. When employed as the team physician, your ethical obligation is to inform

Options:

the player but not the team.
the team but not the player.
neither the team nor the player.
both the team and the player.
the team, the player, and the media

Correct Answer: both the team and the player.

Explanation:

Question 74:

Options:

indomethacin for 3 months.
C-reactive protein and a sed rate.
MRI scan.
bone scan.
follow-up radiograph in 3 months.

Correct Answer: C-reactive protein and a sed rate.

Explanation:

Question 75:

Options:

Osteomyelitis
Lymphoma
Myeloma
Ewing’s sarcoma
Osteosarcoma

Correct Answer: Myeloma

Explanation:

Question 76:

Induction coupling stimulates bone growth through all of the following direct effects EXCEPT:

Options:

Increased proliferation of osteoblasts
Decreased osteoclast differentiation
Increase release of TGF-beta1
Increased expression of BMP2
Increased expression of BMP7

Correct Answer: Increased proliferation of osteoblasts

Explanation:

Question 77:

Standard guidelines necessitate the use of intraoperative neurophysiological monitoring for patients undergoing surgery for which condition?

Options:

Primary lumbar disk herniation
Adolescent idiopathic scoliosis
Cervical spondylotic myelopathy
No conditions; there are no official guidelines

Correct Answer: No conditions; there are no official guidelines

Explanation:

DISCUSSION
There are currently no official guidelines on the appropriate use of neuromonitoring in spine surgery. In general, use of neuromonitoring is at surgeon discretion and often is based on the surgeon's perceived risk for neurologic injury during surgery and medicolegal concerns. In most reports,
neuromonitoring is considered useful in cases of deformity correction, spinal cord decompression, instrumentation placement, and revision surgery. However, even for some of these cases, studies have shown limited benefits of neuromonitoring and substantial associated costs.
RECOMMENDED READINGS
Lall RR, Lall RR, Hauptman JS, Munoz C, Cybulski GR, Koski T, Ganju A, Fessler RG, Smith ZA. Intraoperative neurophysiological monitoring in spine surgery: indications, efficacy, and role of the preoperative checklist. Neurosurg Focus. 2012 Nov;33(5):E10. doi: 10.3171/2012.9.FOCUS12235. Review. PubMed PMID: 23116090.
View Abstract at PubMed
Peeling L, Hentschel S, Fox R, Hall H, Fourney DR. Intraoperative spinal cord and nerve root monitoring: a survey of Canadian spine surgeons. Can J Surg. 2010 Oct;53(5):324-8. PubMed PMID: 20858377.
View
Abstract at PubMed
Garces J, Berry JF, Valle-Giler EP, Sulaiman WA. Intraoperative neurophysiological monitoring for minimally invasive 1- and 2-level transforaminal lumbar interbody fusion: does it improve patient outcome? Ochsner J. 2014 Spring;14(1):57-61. PubMed PMID: 24688334.
View
Abstract at PubMed

Question 78:

Options:

Radiographs
MRI
Erythrocyte sedimentation rate (ESR)
CBC with differential
C-reactive protein (CRP)

Correct Answer: C-reactive protein (CRP)

Explanation:

Question 79:

Options:

Removal of hardware with tendon transfer
Repair of the extensor pollicis longus (EPL) tendon primarily
Thumb interphalangeal (IP) arthrodesis
Nonsurgical treatment with cast placement keeping the thumb in a fully extended position for 4 weeks

Correct Answer: Removal of hardware with tendon transfer

Explanation:

Question 80:

Options:

Creatine
Caffeine
Testosterone
Human growth hormone
Ephedrine

Correct Answer: Creatine

Explanation:

Question 81:

Options:

Metastatic lung cancer
Osteomyelitis
Osteosarcoma
Ewing’s sarcoma
Eosinophilic granuloma

Correct Answer: Ewing’s sarcoma

Explanation:

Question 82:

Options:

Staging studies to assess the extent of disease
Immediate stabilization of the fracture with an intramedullary nail
Curetting and bone culture
Segmental resection of the tibia and allograft reconstruction DISCUSSION… This patient has a pathologic fracture; in patients older than age 50, the most likely diagnosis is metastatic carcinoma or hematopoietic malignancy. A systemic work-up with staging imaging studies and laboratory tests as outlined by Rougraff and associates will identify the primary site of disease in approximately 90% of patients. A biopsy may not be necessary, and this protocol will also effectively exclude a primary sarcoma in the vast majority of patients. The other options all initiate treatment without first evaluating for extent of disease and diagnosis. If this turns out to be a sarcoma, stabilization or curetting the lesion might make subsequent limb salvage difficult or impossible. Segmental resection adds unnecessary morbidity to the surgical procedure in the more common circumstance that this is revealed to be metastatic carcinoma.

Correct Answer: Staging studies to assess the extent of disease

Explanation:

Question 83:

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

Options:

cemented bipolar hemiarthroplasty.
cementless bipolar hemiarthroplasty.
hybrid total hip arthroplasty.
cementless total hip arthroplasty.
open reduction and internal fixation.

Correct Answer: open reduction and internal fixation.

Explanation:

Question 84:

0 mg/L (reference range, 0.08-3.1 mg/L) and erythrocyte sedimentation rate (ESR) is 5 mm/h (reference range, 0-20 mm/h). What is the most appropriate next step in management of the patient?

Options:

Aspiration of the hip to rule out an infectious process
Complete blood count with differential
Observation
Bone scan

Correct Answer: Observation

Explanation:

Both CRP and ESR results are negative, so aspiration of the hip to rule out periprosthetic hip infection is not recommended. The pain may be the result of a noninfectious process such as polyethylene wear with lysis or a muscle strain. A bone scan is of limited value, as is any further bloodwork. If the symptoms continue, further imaging may be of value.
Cryotherapy has been demonstrated to achieve what effect after total knee replacement?
Decreased transfusion requirement
Improved pain, swelling, and analgesia
Improved range of motion at the time of discharge
Better long-term knee range of motion
Corrent answer: 3
In a meta-analysis of randomized controlled trials on the efficacy of cryotherapy after total knee arthroplasty, patients treated with cryotherapy had less blood loss but no difference in transfusion requirements. There was better range of motion at the time of discharge from the hospital. There was no improvement in pain, swelling, or analgesia requirements. Patients treated with cryotherapy did not have better long-term range of motion.
Compared to retention of the native patella in primary total knee arthroplasty, routine patella resurfacing is associated with
no patellar complications.
an increased occurrence of anterior knee pain.
a decreased patellar fracture rate.
a decreased risk for revision surgery.
Despite concerns regarding fracture, osteonecrosis, and patellar clunk, the routine retention of the native patella during primary total knee replacement is associated with a 20% to 30% increased revision risk in large joint registries. In addition, the retention of the native patella results in a 5.7% revision surgery rate in patients with anterior knee pain.
What clinical outcome is associated with total hip replacements that have metal-metal bearings (compared to total hip replacements with metal-polyethylene bearings)?
Soft-tissue sarcomas
Similar revision rates at 5 years
Increased nephrotoxicity
Pseudotumors
Patients with metal-metal total hip bearings have higher levels of cobalt and chromium in the bloodstream, but systemic migration of wear debris from total hip bearings is also common to total hip arthroplasties with polyethylene bearings. There is no direct evidence that patients with metal-metal total hip arthroplasties experience a higher incidence of cancer. Chromosome abnormalities have been detected in patients with metal-metal hip bearings, and the clinical consequences of this finding remain unknown. Also, pseudotumors can form around the periprosthetic joint space in response to localized metal ion debris and the host inflammatory response, although these tumors are not specific for failed metal-metal total hip arthroplasties. Metal-on-metal hip replacements have higher revision rates compared to conventional hip replacements in multiple registry studies. Although metal-on-metal articulations have not been shown to cause renal failure, they are not recommended in patients with chronic renal insufficiency.
A 55-year-old man with unilateral osteoarthritis of the hip underwent a total hip arthroplasty using cementless fixation. The acetabular cup was 52 mm and the femoral head was 28 mm and made of cobalt-chromium alloy. The bearing surface was made of annealed highly cross-linked polyethylene, with an estimated thickness of 6.5 mm. What should the orthopaedic surgeon tell the patient regarding wear of the bearing surface?
A highly cross-linked polyethylene bearing has superior wear characteristics compared to a conventional polyethylene bearing.
A highly cross-linked polyethylene bearing has similar wear characteristics compared to a conventional polyethylene bearing.
The incidence of osteolysis is expected to be higher with highly cross-linked polyethylene than with conventional polyethylene.
The volumetric wear rate would be lower if a 36-mm femoral head were used.
In a prospective, randomized clinical trial of 100 patients undergoing cementless total hip arthroplasties, the investigators compared highly crossed-linked polyethylene to conventional polyethylene. All of the femoral heads were 28 mm. The mean follow-up was 6.8 years. The mean head penetration was 0.003 mm/year for the highly cross-linked polyethylene group in comparison to 0.051 mm/year for the conventional polyethylene group (P =
.006). The improved wear is seen with larger-diameter heads as well. The volumetric wear rate of highly cross-linked polyethylene is equivalent to slightly higher with a larger head than a 28-mm head. Incidence of periarticular osteolysis is lower with highly cross-linked polyethylene.
A 49-year-old active man has groin pain 3 years after undergoing an uneventful total hip replacement using a cobalt-chrome femoral head articulating against a cobalt-chrome acetabular insert. The pain intensifies with activity and travels down his thigh. Examination and radiographic evaluation are not particularly helpful; there is no evidence of spinal or vascular disease. What is the next step in the evaluation of this patient?
A 3-phase bone scan
Measurement of synovial metal ions levels
Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and
possible hip aspiration
Bearing exchange to a metal-polyethylene combination
Corrent answer: 3
ESR, CRP, and possible hip aspiration is the most logical next step even though at some point, bearing exchange may emerge as the ultimate treatment for a metal-metal adverse reaction in this patient. But the initial workup of a patient with a painful total hip that was otherwise functioning well must include the differential diagnosis of infection, which must be excluded with an appropriate laboratory workup, clinical history, and hip aspiration. The latter study may also help to diagnose a reaction to the metal bearing; cobalt and chromium levels in the aspirate can be investigated, and the color and quantity of the aspirate can be examined along with the cell count. Serum levels of metal ions at this stage could be both helpful and difficult to interpret.
Figures A and B are the radiographs of a 25-year-old woman whose right knee pain has progressed during the last several years to pain with any activity and pain at night. What is the most appropriate treatment?
Proximal tibial osteotomy
Distal femoral osteotomy
Lateral unicompartmental arthroplasty
Total knee arthroplasty
Arthroscopic partial lateral meniscectomy
Corrent answer: 2
This patient is a good candidate for a joint-preserving procedure. Her symptoms and radiographic findings reveal valgus malalignment of the knee with narrowing of the lateral joint space. The alignment can be corrected with a varus-producing distal osteotomy. Most patients do not proceed to knee arthroplasty for at least 10 years after this procedure. Osteotomy is preferred over partial or total knee arthroplasty because of the patient's young age.
Varus proximal tibial osteotomy would result in joint line obliquity.
An orthopaedic surgeon noticed a displaced calcar fracture during stem insertion when performing total hip arthroplasty using cementless fixation. What is the most appropriate course of action?
Intraoperative exploration to determine the extent of the fracture
Use of a longer stem without fixation of the calcar fracture
Complete insertion of the stem and measures to protect the patient against full weight bearing for 4 weeks
Removal of the stem, internal fixation of the fracture, and definitive reconstruction at a later stage after the fracture has healed
Calcar fractures can occur with both cemented and cementless stem fixation during surgery. The distal extent of the fracture must be identified either by direct visualization or intraoperative radiograph prior to fixation or implantation of the femoral component. The recommended treatment is to fix the calcar fracture with cerclage wires/cables to restore the mechanical stability of the femoral metaphysis. The same stem can be inserted successfully. The majority of these fractures unite without adverse stem fixation problems.
A 48-year-old woman had an 8-month history of spontaneous onset of left medial knee pain. She was otherwise healthy with an unremarkable past medical history. Prior to the onset of knee pain, she jogged, played tennis, and golfed regularly. She wished to remain active. Examination showed a fit woman with a BMI of 26, a stable left
knee with full range of motion, and some mild medial joint line tenderness. Radiograph results were normal. An MRI scan showed diffuse grade 3 and a focal area of grade 4 chondromalacia on the medial femoral condyle. The medial meniscus had a degenerative signal but no tear. The remainder of the knee showed no additional pathology. What is the most appropriate initial treatment?
Lateral heel wedge
Low-impact aerobic exercises
Glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day
Arthroscopic debridement and microfracture of the focal area of grade 4 chondromalacia to reduce risk for progression
This patient has early medial compartmental osteoarthritis of her knee. According to the 2008 AAOS Clinical Practice Guideline,
Treatment of Osteoarthritis of the Knee (Non-Arthroplasty)
, there is Level 1 evidence and an "A" recommendation for the use of low-impact aerobic exercises. The guideline also has "A" recommendations with Level 1 evidence indicating that glucosamine and chondroitin should not be prescribed and that arthroscopic debridement not be performed in the absence of symptoms of a meniscal tear or loose body. Lateral heal wedge is not appropriate; the AAOS guideline provides a "B" recommendation with Level 2 evidence indicating that a lateral heal wedge not be prescribed.
Figure 36 is the postoperative photograph of a patient who underwent a total knee arthroplasty 10 days after surgery. Knee aspiration suggests a
Streptococcus
infection.
Stop physical therapy and institute oral antibiotics.
Stop physical therapy and institute intravenous (IV) antibiotics.
Open irrigation and debridement, polyethylene spacer exchange, and IV antibiotics
Remove components and insert an antibiotic spacer.
An acute postoperative infection during the first 2 to 4 weeks should be treated with a return to the operating room for open irrigation and debridement of the wound. Polyethylene spacer exchange aides in washing out the entire knee joint. IV antibiotics are also indicated in this situation. To address persistent wound drainage, there is no role for oral or IV antibiotics alone. Removal of the arthroplasty components is recommended for infections after the initial 2- to 4-week postoperative period. However, several recent publications demonstrate a failure rate higher than 50% when the organism is a methicillin-resistant
Staphylococcus aureus
. Six weeks after surgery, this scenario is no longer considered an acute postoperative infection, and most authors recommend a 2-stage protocol with removal of components and placement of an antibiotic-impregnated cement spacer and 4 to 6 weeks of IV antibiotics.
What is the difference in outcome when comparing high tibial osteotomy (HTO) to total knee arthroplasty (TKA)?
TKA has a longer recovery period than HTO.
HTO provides more complete pain relief than TKA.
HTO is more reliable in older patients than TKA.
HTO outcomes among thin, active, young patients who undergo this procedure approach outcomes associated with TKA.
The ideal candidate for HTO is a thin, active person with a stable knee, unicompartmental knee symptoms, and age younger than 60. TKA offers a shorter recovery period and more complete pain relief than HTO. TKA is believed to be more reliable than HTO for patients older than age 60.
Figure 39 is a radiograph of a 72-year-old man who underwent an open reduction and internal fixation of a right femoral neck fracture. After 3 months he started to develop pain, and during the next 8 months he complained of progressive pain and shortening of the hip. What is the most appropriate treatment?
Girdlestone
Total hip replacement
Hardware removal
Hardware removal with revision open reductions and internal fixation
Corrent answer: 2
Even though a relatively short amount of time has passed since the index surgery, this patient has developed significant osteonecrosis that has caused collapse of the bony structures and the hardware prominent. Total hip replacement gives the most efficient pain relief. Hardware removal with or without re-reduction does not provide reliable pain relief. A girdlestone does not allow the patient to function.
Figure 40 is the radiograph of a 68-year-old woman who has right knee pain that is limiting her activity and severe preoperative valgus deformity. During total knee arthroplasty, what pathologic features are typically encountered?
Lateral femoral hypoplasia
Internal rotation of the tibia relative to the femur
Medial patella tracking
Tight medial collateral ligament
Corrent answer: 1
In patients with severe valgus deformity, problems frequently encountered include loose or attenuated medial collateral ligament, tight lateral retinaculum and lateral ligamentous structures (lateral collateral, posterolateral corner), atrophic lateral femoral condyle, lateral patella tracking, and external rotation of the tibia relative to the femur. The hypoplastic lateral condyle can cause internal rotation of the anteroposterior cutting block if the posterior condyler line is used for rotational alignment. The medial soft tissues are typically attenuated and stretched.
A 59-year-old active woman underwent elective total hip replacement using a posterior approach. She had minimal pain and was discharged to home 2 days after surgery. Four weeks later she dislocated her hip while shaving her legs. She underwent a closed reduction in the emergency department. Postreduction radiographs show a reduced hip with well-fixed components in satisfactory alignment. What is the most appropriate management of this condition from this point forward?
Observation and patient education regarding hip dislocation precautions
Revision to a larger-diameter femoral head
Revision to a constrained acetabular component
Application of a hip orthosis for 3 months
Corrent answer: 1
First-time early dislocations are often successfully treated without revision surgery, especially when there is no component malalignment. In this clinical scenario, it appears the patient would benefit from better education about dislocation precautions. Hip orthoses are of questionable benefit unless the patient is cognitively impaired. Revision surgery can be successful, but is usually reserved for patients with recurrent dislocations.
Patellar pain, subluxation, or dislocation after total knee arthroplasty can result from which of the following component orientations?
Internal rotation of the tibial component
Lateralization of the tibial component
Lateralization of the femoral component
External rotation of the femoral component
Corrent answer: 1
Internal rotation of the components of a total knee arthroplasty, both the tibial and femoral components, can lead to symptoms ranging from patellar pain to dislocation. Most researchers agree that proper external rotation of the femoral component is parallel or nearly so to the femoral epicondylar axis with the knee in the 90-degree flexed position. Proper rotational positioning of the tibial component places the midportion of the tibial component rotationally aligned within the medial one-third of the tibial tubercle. Internal rotation of the tibial component causes relative lateralization of the tibial tubercle and the extensor mechanism. Lateralization of the femoral component moves the trochlear groove laterally. Lateralization of the tibial component moves the tibial tubercle medially, which may be beneficial to patellar tracking.
How does the risk for periprosthetic infection after total knee arthroplasty compare to risk for infection after total hip arthroplasty?
Higher in primary arthroplasty
Lower in primary arthroplasty
Lower in revision arthroplasty
Equivalent in both primary and revision arthroplasty
Corrent answer: 1
Risk for periprosthetic infection is higher in the knee (1%-2%) than it is in the hip (0.3%-1.3%). The risk for infection is higher after revision joint replacement surgery compared to primary joint replacement surgery.
Osteoarthritis is not associated with a higher risk for periprosthetic infection, but certain inflammatory conditions such as rheumatoid arthritis and psoriatic arthritis place patients at higher risk for postoperative infection.
What factor is associated with a higher risk for dislocation after total hip arthroplasty?
Male gender
Previous hip surgery
A direct lateral surgical approach
Metal-on-metal bearing surfaces
Corrent answer: 2
Dislocation after total hip arthroplasty is a multifactorial problem. Numerous risk factors may act independently or cumulatively to increase risk for this complication. Previous hip surgery of any kind is associated with a twofold increased risk for dislocation. Other risk factors include female gender, impaired mental status, inflammatory arthritis, and older age. Numerous studies have shown a lower dislocation rate with a direct lateral approach, although surgical techniques such as capsular repair have significantly lowered the incidence of dislocation after using the posterior approach. Metal-on-metal bearings have been associated with other complications such as adverse tissue reactions but are often used with larger-diameter bearings, which pose lower risk for dislocation.
What surgical technique has been associated with increased risk for recurrent dislocation after revision total hip arthroplasty?
Posterior capsulorrhaphy
Use of a jumbo cup
Use of a lateralized liner
Use of a larger femoral head diameter
Corrent answer: 2
When addressing recurrent dislocation after total hip arthroplasty, surgical considerations that must be addressed include approach, soft-tissue tension, component positioning, impingement, head size, and acetabular liner profile. These considerations most often involve tensioning or augmentation of soft tissues, as in capsulorrhaphy or trochanteric advancement; correction of malpositioned components; use of larger femoral head sizes that increase motion before impingement; improving the head-to-neck ratio; and increasing femoral offset. The use of a larger-diameter acetabular component may lead to soft-tissue overgrowth around the liner, causing impingement and increasing the risk for recurrent dislocation.
A 67-year-old active man returns for routine follow up 12 years after hip replacement. He has no hip pain. Radiographs revealed a
well-circumscribed osteolytic lesion around a single acetabular screw. All hip components were perfectly positioned. Six months later, comparison radiographs show an increase in the size of the osteolytic lesion. A CT scan shows a well-described lesion that is 3 cm at its largest diameter and is localized around 1 screw hole with an eccentric femoral head. What treatment is appropriate, assuming well-fixed cementless total hip components exist?
Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting
Revision of the acetabular component to a newer design without screws
Removal of the screw, revision of the polyethylene liner, and stem cell injection into the lytic lesion
Removal of the offending screw from the metal socket and placement of a new polyethylene liner in the existing socket
With a well-fixed acetabular metal shell and a localized osteolytic lesion, good outcomes can be expected with liner revision in this clinical scenario with retention of the metal socket, assuming no damage to the components or other unexpected findings during revision surgery. Here, complete cup revision is not warranted considering the appropriate implant position. Beaule and associates reviewed 83 consecutive patients (90 hips) in which a well-fixed acetabular component was retained in clinical scenarios such as the one described; no hip showed recurrence or expansion of periacetabular osteolytic lesions. If the metal cup is unstable, or if the osteolytic lesion is not amenable to debridement through the screw hole, acetabular component revision may be indicated.
What has been identified as a risk factor for total knee arthroplasty failure after previous high tibial osteotomy?
Body mass index higher than 35
Female gender
Preoperative stiffness
Advanced age
Increased weight, male gender, young age at the time of total knee arthroplasty, laxity, and limb malalignment preoperatively have been identified
as risk factors for early failure for total knee arthroplasty following high tibial osteotomy.
You are caring for an 18-year-old boy with severe hip arthritis and pain from a missed slipped capital femoral epiphysis. You decide that a hip arthrodesis is the best treatment option. What is the optimum position for a hip arthrodesis to maximize function and prevent complications?
0° external rotation, 0° adduction, 0° hip flexion
5° external rotation, 5° adduction, 20° hip flexion
5° external rotation, 15° abduction, 5° hip flexion
15° external rotation, 0° adduction, 20° hip flexion
15° external rotation, 15° abduction, 5° hip flexion
Hip arthrodesis is a salvage procedure for patients with hip arthritis without ipsilateral knee, contralateral hip, or lumbar spine pathology. The optimal position for hip arthrodesis is 5 degrees of adduction, 5-10 degrees of external rotation, and 20-35 degrees of hip flexion.
In their review, Beaule et al. discuss the current indications and techniques regarding hip arthrodesis including appropriate leg position, surgical techniques, methods to optimize function, and later conversion to hip arthroplasty.
Callaghan et al. evaluated the long term efficacy (20-25 yrs) of hip arthrodesis. They found the onset of ipsilateral knee, contralateral hip, or lumbar spine pathology usually began 20 years after the arthrodesis. Of their patients, they found a 15% rate of conversion to hip arthroplasty by 20 years.
What limits indications for the use of constrained liners?
Association with periprosthetic fracture
Technical difficulty associated with insertion
High costs associated with their use
High failure rates associated with their use
Corrent answer: 4
Because of reports of relatively high failure rates associated with constrained liners, indications are limited to continued instability after appropriate component position or deficient abductor mechanism and instability. Neither cost nor technical insertion issues are relevant with regard to indications for use. Periprosthetic fractures are not associated with constrained liner usage.
What serum inflammatory marker has the highest correlation with periprosthetic joint infection?
C-reactive protein
Serum white blood cell count
Erythrocyte sedimentation rate
Interleukin 6 (IL-6)
Although CRP and ESR can be elevated in the setting of infection, IL-6 has been shown to have the highest correlation with infection. Serum white blood cell count has been shown to be ineffective in correlating with periprosthetic joint infection.
A 68-year-old man reports hip pain 15 years after successful cementless total hip arthroplasty. Radiographs show 3 mm of linear wear of the modular acetabular liner and a retro-acetabular osteolytic lesion. Both the titanium femoral and acetabular components appear to be well fixed. The orthopaedic surgeon recommends revision of the acetabular liner and femoral head. This patient is at increased risk for
dislocation.
periprosthetic fracture.
infection.
progressive osteolysis.
Isolated acetabular liner revision is frequently performed in cases of liner wear and periprosthetic osteolysis in the absence of acetabular component loosening. Many reports have documented an increased incidence of dislocation following this type of revision surgery. This dislocation rate can be reduced by using a larger-diameter femoral head at the time of revision. If the
acetabular component is loose or malpositioned, it should be revised. If the locking mechanism is damaged, then a replacement liner may be cemented into the well-fixed shell. Numerous studies have shown that many osteolytic lesions will reduce in size or heal without bone grafting, and removal of the source of wear debris will arrest the progression of osteolysis. The risk for periprosthetic fracture and infection are lower than risk for dislocation in this setting.
A 61-year-old man with a body mass index of 31 had a 6-month gradual onset of right medial knee pain. Examination revealed a small effusion, stable ligaments, a normally tracking patella, and mild medial joint line tenderness. Standing radiographs show mild medial joint space narrowing. Effective treatment at this stage of early medial compartmental osteoarthritis includes
glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day.
weight loss through dietary management and low-impact aerobic exercises.
arthroscopic debridement and lavage.
a valgus-directing brace.
According to the 2008 AAOS Clinical Practice Guideline,
Treatment of Osteoarthritis of the Knee (Non-Arthroplasty)
, Level 1 evidence confirms that weight loss and exercise benefit patients with knee osteoarthritis. The other responses have either inclusive evidence (a valgus-directing brace) or no evidence to support their use (glucosamine 1500 mg/day and chondroitin sulfate 800 mg/day and arthroscopic debridement and lavage).
The range of knee mobility after total knee replacement is multifactorial and dependent upon implant design, surgical implantation accuracy, and patient-specific variables. What total knee implant design is associated with the most knee flexion after total knee replacement?
Highly conforming articular surface geometry
Higher-flexion femoral component design manufactured to allow the most knee flexion
Posterior cruciate-stabilized implant, with or without a higher flexion
manufacturing modification
Posterior cruciate-retaining design with a mobile bearing, custom implanted based on CT scan data
A posterior cruciate-stabilized implant has the best support in the literature in terms of the most favorable range of motion after knee arthroplasty, regardless of whether the femoral component is designed with a higher flexion variation. The higher flexion design is a manufacturing variation that is intended to increase motion by clearing the posterior condyles in flexion.
Although the knee may not gain more flexion, this design allows for more safety in deep flexion. The long-term outcomes of increased stresses on the polyethylene are not known, however. By itself, a higher-flexion design does not lead to increased knee mobility. The effects of mobile bearings, custom CT scan-based knee implantation, and highly conforming designs on ultimate knee range of motion are uncertain.
In total knee arthroplasty, in vitro testing has shown that crosslinking 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?
Increased ductility
Increased wettability
Diminished fatigue strength
Decreased resistance to abrasive wear
Corrent answer: 3
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 identified as causing implant failure in most recent clinical trials, but remain the most important mechanical issues associated with current material processing methods.
What factor is associated with a high risk for developing pseudotumors after metal-on-metal hip resurfacing?
Large-diameter components
Age 40 or older for men
Age 40 or younger for women
Diagnosis of primary osteoarthritis
Corrent answer: 3
The recent experience of a large clinical cohort revealed the most likely risk factors as female gender, age younger than 40, small components, and the diagnosis of hip dysplasia causing osteoarthritis. Failure was least likely among men and procedures involving larger components. These data have prompted some authors to caution against use in women and to primarily target candidates who are men younger than age 50. Small components may be more prone to failure because of malpositioning and edge loading, which have been noted to be more common in dysplasia cases.
A 70-year-old man is scheduled to undergo bearing surface revision for wear and osteolysis 10 years after cementless total hip arthroplasty. The femoral head is 28 mm alumina-oxide ceramic material. The components are in good position, and there is no evidence of fixation loosening of either component by radiograph or preoperative bone scan. What outcome is associated with isolated polyethylene exchange?
Reduced risk for future wear and osteolysis with a larger femoral head
Reduced risk for future wear and osteolysis with a cobalt chrome femoral head
Similar risk for dislocation compared to primary total hip arthroplasty
Increased risk for dislocation compared to primary total hip arthroplasty
Corrent answer: 4
The major complication associated with polyethylene exchange is postoperative dislocation. Maloney and associates noted a dislocation rate of 11% in a study of 35 hips after such revision. Boucher and associates reported a 25% rate of dislocation in a study of 25 patients. Larger femoral heads result in higher volumetric wear in contrast to smaller-diameter heads. Stem revision is not indicated because there is no fixation loosening. Moreover, stem biomaterial has no effect on polyethylene wear.
A healthy, active 68-year-old woman had a total hip arthroplasty 3 months ago. She has been to the emergency department with a posterior dislocation 3 times during the last 2 months. Plain radiographs and a CT scan confirm that the acetabular component is oriented in 5 degrees of retroversion and 55 degrees of abduction.
What is the most appropriate treatment?
Revision of the femoral and acetabular components
Maximizing head-neck ratio and increasing head length
Acetabular component revision
Closed reduction with an abduction brace and reinforcement of hip precautions
Acetabular malposition can lead to recurrent instability. When this cause is confirmed, reorientation of the component can lead to successful revision surgery. Revision of the femoral component may not be necessary if the acetabular component is repositioned. Increasing length and maximizing head-neck ratio cannot make up for component malposition. There is no role for nonsurgical treatment in the setting of recurrent instability with component malposition in an active, healthy patient.
A 55-year-old woman with history of HIV infection is scheduled for revision total knee arthroplasty to address instability. The index surgery was done 3 years ago. What is the white blood cell (WBC) count threshold in the synovial fluid for an infection diagnosis?

Question 85:

Options:

Ligamentum flavum
Lumbar synovial cyst
Tarlov cyst
Pseudomeningocele
Herniated nucleus pulposus

Correct Answer: Lumbar synovial cyst

Explanation:

Question 86:

Options:

L4 nerve root radiculopathy
L5 nerve root radiculopathy
Associated bowel and bladder dysfunction
Symptoms associated with arachnoiditis
Wide-based gait, left-sided Hoffman’s sign

Correct Answer: L4 nerve root radiculopathy

Explanation:

Question 87:

Options:

Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting
Revision of the acetabular component to a newer design without screws
Removal of the screw, revision of the polyethylene liner, and stem cell injection into the lytic lesion
Removal of the offending screw from the metal socket and placement of a new polyethylene liner in the existing socket

Correct Answer: Revision of the polyethylene liner, removal of the screw, and debridement of the osteolytic lesion with or without bone grafting

Explanation:

Question 88:

A 72-year-old woman falls onto her left hip after tripping over a curb during her daily 3-mile walk. An injury radiograph is shown in Figure A. What is the best long term solution?

Options:

Cannulated screws
Valgus intertrochanteric osteotomy
Unipolar hemiarthroplasty
Bipolar hemiarthroplasty
Total hip arthroplasty

Correct Answer: Unipolar hemiarthroplasty

Explanation:

Question 89:

A 65-year-old woman has significant neck pain after falling and striking her head. A radiograph and sagittal CT scan are shown in Figures 23a and 23b. What is the most likely diagnosis?

Options:

Degenerative spondylolisthesis
Superior facet fracture
Inferior facet fracture
Perched unilateral facet dislocation
Bilateral facet dislocation

Correct Answer: Perched unilateral facet dislocation

Explanation:

Question 90:

Options:

Infected total knee arthroplasty
Polyethylene wear-related synovitis
Rheumatoid arthritis synovitis
Gout
Tibial component loosening

Correct Answer: Polyethylene wear-related synovitis

Explanation:

DISCUSSION: Polyethylene wear debris can result in significant synovitis and subsequent cloudy appearing synovial fluid. Typically, laboratory studies show a WBC of less than 30,000/mm
3
and no left shift. Cytologic examination can reveal intra-articular polyethylene particles. Infected total knee arthroplasty is extremely uncommon in a healthy, immune-competent patient who has a normal preoperative erythrocyte sedimentation rate and C-reactive protein level.
REFERENCE: Barrack RL, Jennings RW, Wolfe MW, Bertot AJ: The value of preoperative aspiration before total knee revision. Clin Orthop 1997;345:8-16.

Question 91:

Figure 19 shows the radiograph of a 45-year-old woman who has a painful nonunion. Treatment should consist of

Options:

revision internal fixation with a longer side plate and bone grafting.
open reduction and internal fixation with a 95° fixed angle device and bone grafting.
hardware removal and retrograde intramedullary nailing.
placement of an implantable bone stimulator.
proximal femoral resection and total hip arthroplasty.

Correct Answer: open reduction and internal fixation with a 95° fixed angle device and bone grafting.

Explanation:

Question 92:

Options:

Arthroscopy of the wrist
CT of the wrist
PA clenched fist radiograph
Electromyography and nerve conduction velocity studies
AP and lateral radiographs of the forearm

Correct Answer: PA clenched fist radiograph

Explanation:

Question 93:

Options:

Metatarsophalangeal joint arthrodesis
Medial capsular release with lengthening of the abductor hallucis
Medial capsular release with lateral sesamoid excision
Proximal phalangeal lateral closing wedge osteotomy
Medial capsular lengthening and split extensor hallucis longus tendon transfer

Correct Answer: Medial capsular lengthening and split extensor hallucis longus tendon transfer

Explanation:

DISCUSSION: The patient has a flexible hallux varus that is a complication of the bunion surgery. With joints that are not arthritic and still flexible, a medial release is necessary to realign the joint. The extensor hallucis longus split transfer helps maintain position and still preserve motion at the interphalangeal joint level. Arthrodesis is a salvage procedure. Soft-tissue releases alone are most likely inadequate. Excision of the lateral sesamoid is contraindicated because that further compromises the forces resisting hallux varus. Phalangeal osteotomy would not address the medial subluxation at the metatarsophalangeal joint.
REFERENCES: Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 27-32.
Coughlin MJ, Mann RA, Saltzman CL (eds): Surgery of the Foot and Ankle, ed 8. Philadelphia, PA, Mosby, 2007, pp 345-351.

Question 94:

- The radiograph shown in Figure 50a and the CT scan shown in Figure 50b reveal a lesion in the left femoral neck of a 12-year-old boy who has pain in the left hip. The most likely cause of the osteopenia of the left proximal femur is

Options:

disuse osteopenia
paraendocrine effect of the tumor
abnormally increased density on the right side
side effect of the treatment of the lesion
extensive tumor involvement of the left hip

Correct Answer: disuse osteopenia

Explanation:

Question 95:

Options:

IV antibiotics.
arthroscopic irrigation and debridement, following by IV antibiotics.
irrigation and debridement, polyethylene exchange, and IV antibiotics.
one-stage component removal and reimplantation, followed by IV antibiotics.
two-stage component removal and reimplantation, with IV antibiotics in the interim period.

Correct Answer: irrigation and debridement, polyethylene exchange, and IV antibiotics.

Explanation:

Question 96:

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

Options:

Patellar
Popliteal
Semitendinosus
Semimembranosus
Biceps femoris

Correct Answer: Popliteal

Explanation:

Question 97:

Options:

Myocyte
T-cell
Synovial cell
Osteocyte
Fibromyoblast

Correct Answer: Fibromyoblast

Explanation:

Question 98:

Options:

AP pelvis
Outlet obturator oblique view
Inlet iliac oblique view
Iliac oblique view
Obturator oblique view

Correct Answer: AP pelvis

Explanation:

Question 99:

Options:

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

Correct Answer: Explore the artery

Explanation:

Question 100:

A B Figures 19a and 19b are the CT scans of an 18-year-old man who was a restrained driver in a rollover motor vehicle collision. What was the primary mechanism of injury?

Options:

Axial load
Rotation
Extension
Distraction

Correct Answer: Distraction

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

Orthopedic Board Review MCQs: Deformity, Foot, & Fracture | Part 252

Key Takeaway

About This Board Review Set

How to Use the Interactive Quiz

Topics Covered in Part 252

Sample Questions from This Set

Why Active MCQ Practice Works

Chapter Index