ONLINE ORTHOPEDIC MCQS ANATOMY08

1.       During a retroperitoneal approach to the L4-5 disk, what structure must be ligated
to safely mobilize the common iliac vessels toward the midline from laterally and
gain exposure?

 

1-         Obturator vein

2-         Iliolumbar vein

3-         External iliac vein

4-         Middle sacral artery

5-         Hypogastric artery

 

PREFERRED RESPONSE: 2

 

DISCUSSION: To mobilize the common iliac vessels across the midline, the iliolumbar vein must be ligated.  It has a short trunk and can be torn if mobilization is attempted without ligation.  It is the only branch off the common iliacs (there are no arterial branches) prior to the terminal branches, the internal (hypogastric) and external iliacs.  The middle sacral vessels run distally from the axilla of the bifurcation and are a factor when accessing the L5-S1 disk.

 

REFERENCES: Baker JK, Reardon PR, Reardon MJ, et al: Vascular injury in anterior lumbar surgery.  Spine 1993;18:2227-2230.

Lewis WH: Gray’s Anatomy of the Human Body: The Veins of the Lower Extremity, Abdomen, and Pelvis, ed 20.  Philadelphia, PA, Lea & Febiger, 2000.

 

 

2.       The injection shown in Figures 1a and 1b would most benefit a patient who reports which of the following symptoms?

 

1-         Dorsal foot pain extending into the great toe

2-         Foot pain extending along the lateral border of the foot

3-         Pain extending into the foot in a stocking distribution

4-         Anterior thigh and shin pain ending at the ankle

5-         Lateral foot paresthesias

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The images demonstrate a L5 selective root block as it exits the L5-S1 foramen.  This root block best helps relieve pain or paresthesias in the L5 distribution, which is the dorsal first web space and the great toe.  The lateral foot is an S1 distribution and would need to be blocked through the posterior first sacral foramen.  The anterior shin and thigh represent the
L4 root which exits a level above this at the L4-5 foramen.  A stocking distribution is nonanatomic and not indicative of a specific root.

 

REFERENCES: Magee D: Principles and concepts, in Orthopaedic Physical Assessment, ed 3.  Philadelphia, PA, WB Saunders, 1997, pp 1-18.

Aeschbach A, Mekhail NA: Common nerve blocks in chronic pain management.  Anesthesiol Clin North Am 2000;18:429-459.

 

 

3.       In Figure 2, which of the following structures is the primary stabilizer in preventing valgus instability of the elbow?

 

1-         A

2-         B

3-         C

4-         D

5-         E

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The anterior bundle of the medial collateral ligament is the prime stabilizer of the medial aspect of the elbow and is indicated by “B” in the figure.  When intact, this anterior bundle of the medial collateral ligament is a restraint to valgus instability of the elbow.  The posterior bundle is regarded as a secondary stabilizer of the medial elbow (C).  The transverse bundle (D), annular ligament (A), and biceps tendon (E) do not play a role in valgus stability of the elbow.

 

REFERENCES: Jobe F, Elattrache N: Diagnosis and treatment of ulnar collateral ligament injuries in athletes, in Morrey B (ed): The Elbow and Its Disorders.  Philadelphia, PA,
WB Saunders, 1993, p 566.

Wilkins KE, Morrey BF, Jobe FW, et al: The elbow.  Instr Course Lect 1991;40:1-87.

 

 

4.       When performing surgical excision of the lesion shown in the MRI scan in Figure 3,
what nerve is most likely at risk?

 

1-         Deep branch of the ulnar nerve

2-         Anterior interosseous branch of the median nerve

3-         Recurrent branch of the median nerve

4-         Recurrent branch of the ulnar nerve

5-         Palmar cutaneous branch of the ulnar nerve

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scan shows a large mass (lipoma) in the thenar muscles of the palm.  The recurrent motor branch of the median nerve innervates the thenar muscles.  The anterior interosseous nerve (AIN) in the proximal forearm innervates the flexor pollicis longus, pronator quadratus, and flexor digitorum pollicis to the index and frequently the middle finger.  The terminal branch of the AIN innervates only the wrist capsule.  The palmar cutaneous branch of the ulnar nerve is a sensory structure to the hypothenar area.  There is no commonly described recurrent branch of the ulnar nerve.

 

REFERENCE: Kozin SH: The anatomy of the recurrent branch of the median nerve.  J Hand Surg Am 1998;23:852-858.

 

 

5.       Figure 4a shows the radiograph of a 20-year-old man who has an injury to the right shoulder.  Figure 4b shows an arthroscopic view (posterior portal).  The arrow points to a

 

1-         rotator cuff tear.

2-         bare area.

3-         Hill-Sachs defect.

4-         Bankart tear.

5-         glenoid fracture.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiograph shows an anterior dislocation of the shoulder.  A frequently encountered sequela of this is a compression fracture of the posterolateral humeral head, commonly referred to as a Hill-Sachs defect.  The arthroscopic view of the glenohumeral joint visualizes the posterior aspect of the humeral head.  In the image, the area devoid of cartilage to the right is the bare area.  The indentation seen to the left is a Hill-Sachs defect. 

 

REFERENCES: Matsen FA, Thomas SC, Rockwood CA, et al: Glenohumeral instability, in Rockwood CA, Matsen FA (eds): The Shoulder, ed 2.  Philadelphia, PA, WB Saunders, 1998,
pp 611-754.

Mazzocca AD, Noerdlinger M, Cole B, et al: Arthroscopy of the shoulder: Indications and general principals of techniques, in McGinty JB (ed): Operative Arthroscopy, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 412-427.

 

 

6.       A 15-year-old girl who swims the breaststroke has had hip pain after training excessively for a national level competition.  Based on the MRI scans shown in Figures 5a through 5c, what is the most likely diagnosis?

 

1-         Femoral neck stress fracture

2-         External rotator muscle tear

3-         Slipped capital femoral epiphysis

4-         Superior acetabular labral tear

5-         Acetabular dysplasia

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The MRI scans reveal open physes but no evidence of a slipped capital femoral epiphysis, labral tear, or acetabular dysplasia.  The femoral neck does not show evidence of a fracture.  The muscle tear seen on the right side lies near the musculotendinous junction of the external rotators of the hip at the level of the lesser trochanter, representing the obturator externus.  This is consistent with the forced motion required for the breaststroke kick.

 

REFERENCES: Grote K, Lincoln TL, Gamble JG: Hip adductor injury in competitive swimmers.  Am J Sports Med 2004;32:104-108.

Clemente C: Anatomy: A Regional Atlas of the Human Body, ed 3.   Baltimore-Munich, Urban and Schwarzenberg, 1987, Figures 429, 430.

 

 

7.       During placement of an external fixator for a distal radius fracture, the most commonly injured nerve is a branch of which of the following nerves?

 

1-         Ulnar

2-         Median

3-         Superficial radial

4-         Lateral antebrachial cutaneous

5-         Medial antebrachial cutaneous

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Pin track infections and sensory injuries are among the most common complications of external fixation for distal radius fractures.  The proximal pins of most distal radius external fixators are placed in the “bare area” of the distal radius, about four finger-breadths above the radial styloid.  This corresponds to the area where the dorsal sensory branch of the radial nerve penetrates the fascia dorsal to the brachioradialis tendon to become a subcutaneous structure.  Injury to the superficial radial nerve may produce painful dysesthesias and neuromas.

 

REFERENCE: Beldner S, Zlotolow DA, Melone CP, et al: Anatomy of the lateral antebrachial cutaneous and superficial radial nerves in the forearm: A cadaveric and clinical study.  J Hand Surg Am 2005;30:1226-1230.

 

 

8.       Figure 6 shows a sagittal oblique MRI scan.  The arrow is pointing to what structure?

 

1-         Bucket-handle tear of the medial meniscus

2-         Ligament of Humphrey

3-         Ligament of Wrisberg

4-         Posterior intermeniscal ligament

5-         Partial tear of the posterior cruciate ligament

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The meniscofemoral ligaments connect the posterior horn of the lateral meniscus to the intercondylar wall of the medial femoral condyle.  The ligament of Humphrey (arrow) passes anterior to the posterior cruciate ligament, whereas the ligament of Wrisberg passes posterior to the posterior cruciate ligament.  One or the other has been identified in 71% to 100% of cadaver knees, with the ligament of Wrisberg being more common. 

 

REFERENCES: Clarke HD, Scott WN, Insall JN, et al: Anatomy, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 3-66. 

Miller TT: Magnetic resonance imaging of the knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 201-224. 

 

 

9.       An 18-year-old woman sustains a twisting injury of the knee while skiing.  Figures 7a and 7b show the radiograph and coronal MRI scan of the knee.  In addition to the injury shown, what is the most likely associated injury?

 

1-         Medial collateral ligament rupture

2-         Patellar dislocation

3-         Patellar tendon rupture

4-         Anterior cruciate ligament rupture

5-         Posterior cruciate ligament rupture

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The MRI scan shows a Segond fracture, which is a small avulsion of the lateral joint capsule from the anterolateral aspect of the proximal tibia.  It is almost always associated with anterior cruciate ligament rupture and often with a tear of either the medial or lateral meniscus.

 

REFERENCES: Goldman AB, Pavlov H, Rubenstein D: The Segond fracture of the proximal tibia: A small avulsion that reflects major ligamentous damage.  Am J Roentgenol 1988;151:1163-1167.

Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee.  Am J Sports Med 2005;33:131-148.

Miller TT: Magnetic resonance imaging of the knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 201-224. 

 

 

10.     A 42-year-old athletic trainer has a persistent popping sensation about the lateral ankle associated with weakness and pain following a remote injury.  Deficiency in what structure directly leads to this pathology?

 

1-         Lateral talar process

2-         Superior peroneal retinaculum

3-         Inferior peroneal retinaculum

4-         Extensor retinaculum

5-         Crural fascia

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has instability of the peroneal tendon.  The superior peroneal retinaculum is the primary retaining structure preventing peroneal subluxation.  It is a thickening of fascia that arises off the posterior margin of the distal 1 to 2 cm of the fibula and runs posteriorly to blend with the Achilles tendon sheath.  The inferior peroneal retinaculum attaches to the peroneal tubercle of the calcaneus and is not involved in this pathology.  A deficient groove in the posterior distal fibula may also be a contributing factor in the development of
the condition.

 

REFERENCE: Maffuli N, Ferran NA, Oliva F, et al: Recurrent subluxation of the peroneal tendons.  Am J Sports Med 2006;34:986-992.

 

 

11.     A 21-year-old man sustains multiple gunshot wounds to his right upper extremity.  He can not extend his digits or his thumb but can extend and radially deviate his wrist.  An injury to the radial nerve or one of its branches has most likely occurred at which of the following locations?

 

1-         Spiral groove of the humerus

2-         Midshaft of the radius

3-         Radial neck

4-         Anatomic neck of the humerus

5-         Surgical neck of the humerus

 

PREFERRED RESPONSE: 3

 

DISCUSSION: In this patient, the radial nerve is most likely injured at the level of the radial neck.  The radial nerve emerges from the posterior cord of the brachial plexus and travels along the spiral groove of the humerus.  At the level of the lateral humeral condyle, the radial nerve branches into the posterior interosseous nerve after giving off two cutaneous branches, the superficial radial and the posterior cutaneous.  The posterior interosseous nerve travels through the supinator muscle and winds around the radial neck.  At this level, the posterior interosseous nerve is vulnerable to injury, particularly following fracture or penetrating trauma. 

 

REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders.  West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 53.

Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3.  Philadelphia, PA, Harper and Row, 1982, vol 3, pp 428-429.

 

 

12.     A woman with a neck and chest tumor has weakness in the biceps and paresthesias in the thumb.  Brachioradialis and infraspinatus function are normal.  The lesion is affecting which of the following structures?

 

1-         C6

2-         Upper trunk

3-         Middle trunk

4-         Posterior cord

5-         Lateral cord

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The lateral cord terminates as the musculocutaneous nerve and also contributes sensory fibers to the median nerve.  Involvement of the C6 root or upper trunk could potentially cause weakness of the infraspinatus and the brachioradialis.  The middle trunk and the posterior cord do not contribute motor fibers to the thumb or sensory fibers to the thumb.

 

REFERENCE: Kline DG, Hudson AR: Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors.  Philadelphia, PA, WB Saunders, 1995, p 334.

 

 

13.     Figure 8 shows the radiograph of a 76-year-old man who has knee pain and swelling.  History reveals that he underwent total knee arthroplasty 18 years ago.  What is the most likely diagnosis?

 

1-         Loose femoral component

2-         Loose tibial component

3-         Particle-mediated osteolysis

4-         Polyethylene failure

5-         Infection

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiograph reveals complete loss of joint space with particulate metal debris consistent with total polyethylene failure and metal-on-metal articulation.  The components appear to be well fixed and minimal osteolysis is evident.

 

REFERENCES: Kilgus DJ, Moreland JR, Finerman GA, et al: Catastrophic wear of tibial polyethylene inserts.  Clin Orthop Relat Res 1991;273:223-231.

Vince KG: Why knees fail.  J Arthroplasty 2003;18:39-44.

 

 

14.     Which of the following radiographic images is best for detecting anterior acetabular deficiency in the dysplastic hip?

 

1-         Pelvic inlet

2-         Judet

3-         AP pelvis

4-         False profile

5-         Frog lateral

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The false profile view of Lequesne and de Seze is obtained with the patient standing with the affected hip on the cassette, the ipsilateral foot parallel to the cassette, and the pelvis rotated 65 degrees from the plane of the cassette.  This view best assesses anterior coverage of the femoral head.

 

REFERENCES: Garbuz DS, Masri BA, Haddad F, et al: Clinical and radiographic assessment the young adult with symptomatic dysplasia.  Clin Orthop Relat Res 2004;418:18-22.

Delauney S, Dussault RG, Kaplan PA, et al: Radiographic measurements of dysplastic adult hips.  Skelelal Radiol 1997;26:75-81.

 

 

15.     Figure 9 shows the AP radiograph of a 65-year-old man who has knee pain and swelling.  What is the most likely diagnosis?

 

1-         Gout

2-         Chondrocalcinosis (pseudogout)

3-         Hemochromatosis

4-         Rheumatoid arthritis

5-         Ochronosis

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Although all the choices are known causes of joint degeneration (secondary osteoarthritis), only chondrocalcinosis shows distinct linear calcification of the cartilage due to deposition of calcium pyrophosphate crystals.  Gout is a recurrent acute arthritis resulting from the deposition of monosodium urate from supersaturated hyperuricemic body fluids.  Hemochromotosis is characterized by focal or generalized deposition of iron within body tissues.  Arthritis may be present but is less common than other manifestations such as liver cirrhosis, skin pigmentation, diabetes mellitus, and cardiac disease.  Rheumatoid arthritis is a nonspecific, usually symmetric inflammation of peripheral joints resulting in destruction of articular and periarticular structures.  Ochronosis is a hereditary enzyme deficiency (homogentisic acid oxidase) resulting in deposition of homogentisic acid polymers in articular cartilage. 

 

REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, p 188.

Berkow R (ed): The Merck Manual, ed 14.  Rathway, NJ, Merck, 1984, pp 910, 1176, 1200.

 

 

16.     If a surgeon inadvertently burrs through the midlateral wall of C5 during a anterior corpectomy, what structure is at greatest risk for injury?

 

1-         C5 root

2-         C6 root

3-         Internal carotid artery

4-         Vertebral artery

5-         Vagus nerve

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The vertebral artery is contained within the vertebral foramen and thus tethered alongside the vertebral body, making it vulnerable to injury if a drill penetrates the lateral wall.  The C5 root passes over the C5 pedicle and is not in the vicinity.  The C6 root passes under the C5 pedicle but is posterior to the vertebral artery and is only vulnerable at the very posterior-inferior corner.  The carotid artery and the vagus nerve are both within the carotid sheath and well anterior.

 

REFERENCES: Pfeifer BA, Freidberg SR, Jewell ER: Repair of injured vertebral artery in anterior cervical procedures.  Spine 1994;19:1471-1474.

Gerszten PC, Welch WC, King JT: Quality of life assessment in patients undergoing nucleoplasty-based percutaneous discectomy.  J Neurosurg Spine 2006;4:36-42.

 

 

17.     In patients with displaced radial neck fractures treated with open reduction and internal fixation with a plate and screws, the plate must be limited to what surface of the radius to avoid impingement on the proximal ulna?

 

1-         2 cm distal to the articular surface of the radial head

2-         1 cm distal to the articular surface of the radial head

3-         Within a 90-degree arc or safe zone

4-         Within a 120-degree arc or safe zone

5-         Within a 180-degree arc or safe zone

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radial head is covered by cartilage on 360 degrees of its circumference.  However, with the normal range of forearm rotation of 160 to 180 degrees, there is a consistent area that is nonarticulating.  This area is found by palpation of the radial styloid and Lister’s tubercle.  The hardware should be kept within a 90-degree arc on the radial head subtended by these two structures.

 

REFERENCES: Smith GR, Hotchkiss RN: Radial head and neck fractures: Anatomic guidelines for proper placement of internal fixation.  J Shoulder Elbow Surg 1996;5:113-117.

Caputo AE, Mazzocca AD, Santoro VM: The nonarticulating portion of the radial head: Anatomic and clinical correlations for internal fixation.  J Hand Surg Am 1998;23:1082-1090.

 

 

18.       A 57-year-old man reports right hip pain that has been progressive for the past several months.  The pain is exacerbated by weight-bearing activities and improves somewhat with rest.  A radiograph is shown in Figure 10a and a coronal T₁-weighted MRI scan is shown in Figure 10b.  What is the most likely diagnosis?

 

1-         Osteoarthritis of the hip

2-         Osteonecrosis of the hip

3-         Metastatic carcinoma

4-         Femoral head fracture

5-         Rheumatoid arthritis of the hip

 

PREFERRED RESPONSE: 2

 

DISCUSSION: These are classic findings of osteonecrosis of the hip.  The radiograph reveals the subchondral sclerotic pattern commonly seen in osteonecrosis and is quite extensive in this patient.  The MRI scan reveals the typical serpentine-like region of low signal intensity with a central zone where the signal is similar to fat. 

 

REFERENCES: Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA,
WB Saunders, 2002, pp 3160-3162.

Sugano N: Osteonecrosis, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics.  Philadelphia, PA, Mosby International, 2002, pp 877-887.

 

 

19.     The arrow in Figure 11 points toward a finding consistent with which of the following?

 

1-         Metastatic disease

2-         Hemangioma

3-         Flexion-compression fracture

4-         Infection

5-         Diastomatomyelia

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The finding of a unilateral absent pedicle is often referred to as a winking owl sign and is a manifestation of pedicle destruction from metastatic disease.  As the vertebral body is destroyed from the neoplastic process, it extends into the pedicle and destroys the cortical rim that normally creates the oval ring of the pedicle on an AP image.

 

REFERENCES: McLain R, Weinstein J (eds): Rothman-Simeone: The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1999, p 1173.

Koval KJ (ed): Orthopaedic Knowledge Update 7.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, p 674.

 

 

20.     The attachments of the transverse carpal ligament include which of the following structures?

 

1-         Scaphoid and the ulna

2-         Trapezium and the hook of the hamate

3-         Trapezium and the triquetrum

4-         Trapezoid and the hook of the hamate

5-         Trapezoid and the pisiform

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The transverse carpal ligament is the volar boundary of the carpal tunnel.  It attaches to the scaphoid and trapezium radially and the pisiform and the hook of the hamate ulnarly.  The ulna and trapezoid do not receive attachments of the transverse carpal ligament.

 

REFERENCES: Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3.  Philadelphia, PA, Harper and Row, 1982, vol 3, pp 471-472.

Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2.  Philadelphia, PA, Lippincott-Raven, 1994, pp 168-170.

 

 

21.     A 23-year-old woman falls from a bicycle and sustains a right knee injury.  Figures 12a through 12d show radiographs and MRI scans of the knee.  What is the most likely diagnosis?

 

1-         Posterior cruciate ligament avulsion from the tibia

2-         Anterior cruciate ligament avulsion from the tibia

3-         Avulsion of the lateral meniscus anterior horn

4-         Midsubstance posterior cruciate ligament rupture

5-         Midsubstance anterior cruciate ligament rupture

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The radiographs and MRI scans both show an avulsion of the anterior cruciate ligament, which has been described by Meyers and McKeever in three different fracture patterns.  Type I fractures are nondisplaced or have minimal displacement of the anterior margin.  Type II fractures have superior displacement of their anterior aspect with an intact posterior hinge.  Type III fractures are completely displaced.  Although the injury is visible on the radiographs, it is more subtle in adults than children.  Thus, MRI is helpful in clarifying this injury in adults.  Open or arthroscopic reduction and internal fixation is recommended for type II and type III fractures that do not respond to closed reduction. 

 

REFERENCES: Meyers MH, McKeever FM: Fracture of the intercondylar eminence of the tibia.  J Bone Joint Surg Am 1970;52:1677-1684.

Wiss DA, Watson JT: Fractures of the tibial plateau, in Rockwood CA, Green DP, Bucholz RW, et al (eds): Rockwood and Green’s Fractures in Adults.  Philadelphia, PA, Lippincott-Raven, 1996, pp 1920-1953.

Lubowitz JH, Elson WS, Guttmann D: Arthroscopic treatment of tibial plateau fractures: Intercondylar eminence avulsion fractures.  Arthroscopy 2005;21:86-92.

 

 

22.     A 25-year-old man has a mass on the medial aspect of the left knee.  He reports that the mass has been present for several years, but a recent increase in physical activity has resulted in periodic tenderness.  Radiographs are shown in Figures 13a and 13b.  What is the most likely diagnosis?

 

1-         Osteochondroma

2-         Enchondroma

3-         Myositis ossificans

4-         Parosteal osteosarcoma

5-         Prior bony trauma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiographs reveal a sessile lesion projecting from the medial aspect of the distal femur.  The lesion shares the cortex with the bone and the base communicates with the medullary space of the femur.  This is the classic appearance of an osteochondroma, the most common benign tumor of bone.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 103-111.

Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics.  Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

 

 

23.     A previously asymptomatic 40-year-old man injures his shoulder in a fall.  Examination shows that he is unable to lift the hand away from his back while maximally internally rotated.  An axial MRI scan of the shoulder is shown in Figure 14.  What is the most likely diagnosis?

 

1-         Pectoralis major tendon rupture

2-         Supraspinatus rupture

3-         Subscapularis rupture

4-         Bankart tear

5-         Humeral avulsion of the inferior glenohumeral ligament

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scan shows detachment of the subscapularis from its insertion on the lesser tuberosity.  The examination finding is consistent with a positive lift-off test, also indicating a tear of the subscapularis. 

 

REFERENCES: Lyons RP, Green A: Subscapularis tendon tears.  J Am Acad Orthop Surg 2005;13:353-363.

Warner JJ, Higgins L, Parsons IM, et al: Diagnosis and treatment of anterosuperior rotator cuff tears.  J Shoulder Elbow Surg 2001;10:37-46.

 

 

24.     A patient is treated with volar plating for a distal radius fracture.  The CT scan shown in Figure 15 is obtained after union of the fracture because the patient reports ongoing symptoms.  The prominent hardware is most likely injuring what tendon?

 

1-         Extensor pollicis brevis (EPB)

2-         Extensor carpi radialis brevis (ECRB)

3-         Extensor digitorum communis (EDC)

4-         Extensor carpi ulnaris (ECU)

5-         Extensor carpi radialis longus (ECRL)

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Extensor tendon injuries have been reported after volar plating of distal radius fractures.  The CT scan shows prominent dorsal hardware a few millimeters ulnar to Lister’s tubercle.  The second compartment, the ECRL and ECRB, is radial to Lister’s tubercle.  The ECU runs along the distal ulna.  The contents of the fourth dorsal compartment run just ulnar to Lister’s tubercle.  The EDC tendon is likely irritated in this patient.  The EPB runs along the radial border of the radius and is well away from prominent hardware.

 

REFERENCES: Benson EC, Decarvalho A, Mikola EA, et al: Two potential causes of EPL rupture after distal radius volar plate fixation.  Clin Orthop Relat Res 2006;451:218-222.

Cooney WP, Linscheid RL, Dobyns JH (eds): The Wrist: Diagnosis and Operative Treatment.  Philadelphia, PA, Mosby-Year Book, 1998.

 

 

25.     A 9-year-old child sustains a proximal tibial physeal fracture with a hyperextension mechanism.  What structure is at most risk for serious injury?

 

1-         Tibial nerve

2-         Popliteal artery

3-         Common peroneal nerve

4-         Posterior cruciate ligament

5-         Popliteus muscle

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The most serious injury associated with proximal tibial physeal fracture is vascular trauma.  The popliteal artery is tethered by its major branches near the posterior surface of the proximal tibial epiphysis.  During tibial physeal displacement, the popliteal artery is susceptible to injury.  Injuries to the other structures are less common.

 

REFERENCE: Beaty JH, Kasser JR: Rockwood and Wilkins Fractures in Children.  Philadelphia, PA, JB Lippincott, 2006, p 961.

 

 

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

 

1-         Supraspinatus tear

2-         Infraspinatus tear

3-         Suprascapular nerve compression

4-         C5 radiculopathy

5-         Subacromial impingement

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scans show a paralabral cyst, which is most commonly associated with labral tears.  Compression of the suprascapular nerve results in weakness of the supraspinatus and/or infraspinatus depending on the level of compression. 

 

REFERENCES: Piatt BE, Hawkins RJ, Fritz RC, et al: Clinical evaluation and treatment of spinoglenoid notch ganglion cysts.  J Shoulder Elbow Surg 2002;11:600-604.

Inokuchi W, Ogawa K, Horiuchi Y: Magnetic resonance imaging of suprascapular nerve palsy. 
J Shoulder Elbow Surg 1998;7;223-227. 

 

 

27.     The posterior approach to the proximal radius uses what intermuscular interval?

 

1-         Extensor carpi radialis brevis and extensor digitorum communis

2-         Extensor carpi radialis longus and extensor digitorum communis

3-         Extensor digitorum communis and extensor pollicis brevis 

4-         Brachioradialis and flexor carpi radialis

5-         Anconeus and extensor carpi ulnaris

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Knowledge of intermuscular and internervous planes allows safe exposures throughout the body.  The posterior (Thompson) approach to the proximal forearm uses the interval between the extensor carpi radialis brevis and extensor digitorum communis.  The anterior (Henry) approach to the proximal forearm uses the interval between the brachioradialis and the flexor carpi radialis. 

 

REFERENCES: Spinner M: Injuries to the Major Branches of Peripheral Nerves of the Forearm, ed 2.  Philadelphia, PA, WB Saunders, 1978, pp 66-77.

Henry AK: Extensile Exposure, ed 3.  New York, NY, Churchill Livingstone, 1995.

 

 

28.     Which of the following statements best describes the anatomic considerations of the popliteal artery posterior to the knee joint?

 

1-         It lies posterior to the popliteal vein and 9 mm posterior to the posterior aspect of the tibial plateau in 90 degrees of flexion.

2-         It lies anterior to the popliteal vein and 9 mm posterior to the posterior aspect of the tibial plateau in 90 degrees of flexion.

3-         It lies lateral to the popliteal vein and 15 mm posterior to the posterior aspect of the tibial plateau in 90 degrees of flexion.

4-         It lies medial to the popliteal vein and 9 mm posterior to the posterior aspect of the tibial plateau in 90 degrees of flexion.

5-         It lies anterior to the popliteal vein and 15 mm posterior to the posterior aspect of the tibial plateau in 90 degrees of flexion.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Popliteal artery injury during total knee arthroplasty is relatively rare.  Knee flexion, the position that occurs during most of the arthroplasty procedure, allows the popliteal vessels to fall posteriorly, further away from harm.  Anatomically, the popliteal artery lies anterior to the popliteal vein and 9 mm posterior to the posterior aspect of the tibial plateau in
90 degrees of flexion.

 

REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, p 151.

Anderson JE: Grant’s Atlas of Anatomy, ed 7.  Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-53.

 

 

29.       A 62-year-old woman reports diffuse aches and pains of the hip and pelvis.  She denies any significant trauma but does have a history of chronic anemia.  Figure 17a shows a radiograph of the pelvis, and Figures 17b and 17c show T₂-weighted MRI scans.  What is the most likely diagnosis?

 

1-         Chondrosarcoma

2-         Diffuse fibrous dysplasia

3-         Multiple myeloma

4-         Osteoporosis

5-         Bone infarcts

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiograph reveals diffuse osteopenia and areas in the proximal femora that are moth-eaten in appearance.  The extent of the marrow-replacing process is evident on the MRI scans, which reveal signal abnormality throughout the entire pelvis and both proximal femora.  This represents a marrow-packing process, of which multiple myeloma is the best choice.  This diagnosis is also supported by the anemia noted on the patient’s history.  Metastatic carcinoma and lymphoma also may have a similar presentation.

 

REFERENCE: Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA,
WB Saunders, 2002, pp 2189-2216.

 

 

31.     What structure is located at the tip of the arrow in Figure 18?

 

1-         Left L3 nerve root

2-         Right L3 nerve root

3-         Right L4 segmental artery

4-         Right L4 nerve root

5-         Left lateral disk herniation

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The structure shown is the exiting nerve root at the L3-4 disk, which is the right L3 root.

 

REFERENCE: An H: Diagnostic imaging of the spine, in Principles and Techniques of Spine Surgery.  Baltimore, MD, Lippincott Williams & Wilkins, 1998, pp 102-125.

 

 

31.     What structure is located at the tip of the arrow in Figure 18?

 

1-         Left L3 nerve root

2-         Right L3 nerve root

3-         Right L4 segmental artery

4-         Right L4 nerve root

5-         Left lateral disk herniation

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The structure shown is the exiting nerve root at the L3-4 disk, which is the right L3 root.

 

REFERENCE: An H: Diagnostic imaging of the spine, in Principles and Techniques of Spine Surgery.  Baltimore, MD, Lippincott Williams & Wilkins, 1998, pp 102-125.

 

 

32.     A patient undergoes the procedure shown in Figure 19.  An important part of this procedure is preservation of what wrist ligament?

 

1-         Radioscaphocapitate

2-         Scapholunate interosseous

3-         Ulnotriquetral

4-         Volar radioulnar

5-         Deep proximal capitohamate

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Proximal row carpectomy is a salvage wrist procedure that yields a surprisingly stable construct.  This has been attributed to two factors: 1) the congruency of the head of the capitate in the lunate fossa (this articulation is less congruent than the native lunate/lunate fossa relationship, but surprisingly stable), and 2) preservation of the radioscaphocapitate ligament, the most radial of the palmar extrinsic ligaments, which prevents ulnar subluxation after proximal row carpectomy.

 

REFERENCE: Jebson PJ, Engber WD: Proximal row carpectomy.  Tech Hand Up Extrem Surg 1999;3:32-36.

 

 

33.     A 23-year-old woman reports right knee pain and fullness.  The pain is worse with activity but also present at rest.  Radiographs are shown in Figures 20a and 20b.  What is the most likely diagnosis?

 

1-         Osteosarcoma

2-         Chondroblastoma

3-         Stress fracture

4-         Posttraumatic changes

5-         Chondrosarcoma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiographs reveal a predominantly lytic, destructive lesion of the distal femur, although there is a hint of some blastic change as well.  The lesion has violated the cortex, and there is mineralization outside the cortex laterally.  The lateral radiograph suggests a soft-tissue density.  These aggressive changes on radiographs in this age group are strongly suggestive of osteosarcoma.

 

REFERENCES: Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia.  Cancer Control 2001;8:221-231.

Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 175-186.

 

 

34.     What is the structure indicated by the letter “A” in Figure 21?

 

1-         Annular ligament

2-         Lateral ulnar collateral ligament

3-         Accessory collateral ligament

4-         Radial collateral ligament

5-         Transverse ligament

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The ligaments shown are the components of the lateral collateral ligament complex, and the structure indicated by the letter “A” is the radial collateral ligament.  The lateral ulnar collateral ligament is the structure indicated by the letter “C” and the annular ligament is indicated by the letter “B.”  The transverse ligament is a component of the medial collateral ligament complex. 

 

REFERENCES: Morrey BF: Anatomy of the elbow joint, in Morrey BF (ed): The Elbow and Its Disorders.  Philadelphia, PA, WB Saunders, 1993, p 30.

O’Driscoll SW, Bell DF, Morrey BF: Posterolateral rotatory instability of the elbow.  J Bone Joint Surg Am 1991;73:440-446.

 

 

35.     A 16-year-old boy sustains a twisting injury to the left knee while wrestling.  MRI scans are shown in Figures 22a through 22c.  What is the most likely diagnosis?

 

1-         Anterior cruciate ligament rupture

2-         Posterior cruciate ligament rupture

3-         Bucket-handle medial meniscus tear

4-         Lateral meniscus tear

5-         Osteochondral lesion

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scans show a displaced bucket-handle medial meniscus tear that can be visualized on coronal, sagittal, and axial views.  The sagittal view shows the typical “double posterior cruciate ligament sign,” in which the low-signal bucket-handle fragment parallels the normal low-signal posterior cruciate ligament.  The coronal and axial images both show the displaced medial meniscus in the notch. 

 

REFERENCES: Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee.  Am J Sports Med 2005;33:131-148.

Miller TT: Magnetic resonance imaging of the knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 201-224. 

 

 

36.     A 48-year-old woman reports bilateral thigh pain that is limiting her function as a librarian.  A radiograph and a bone scan are shown in Figures 23a and 23b.  What is the most likely diagnosis?

 

1-         Ankylosing spondylitis

2-         Arthrokatadysis

3-         Osteomalacia

4-         Rheumatoid arthritis

5-         Developmental dysplasia

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiograph reveals bilateral severe acetabular protrusio.  The bone scan and history confirm involvement of multiple joints, including the knees and the hindfoot.  Although the first four choices can all cause the acetabular protrusio, the associated multiple joint involvement suggests the diagnosis of rheumatoid arthritis.  Arthrokatadysis, or primary protrusio acetabuli, is often associated with osteomalacia but not other joint disease.  Developmental dysplasia is a common cause of bilateral hip pathology but does not have acetabular protrusio.

 

REFERENCES: Resnick D: Diagnosis of Bone and Joint Disorders, ed 3.  Philadelphia, PA,
WB Saunders, 1995, pp 956-957.

Wheeless’ Textbook of Orthopaedics: Acetabular Protrusio.  www.wheelessonline.com/ortho/acetabular_protrusio

 

 

37.     At the level of tibial bone resection in total knee arthroplasty, where does the common peroneal nerve lie?

 

1-         Deep to the arcuate ligament

2-         Closer to bone in larger legs

3-         On the muscle belly of the popliteus

4-         On the bony posterolateral corner of the tibia

5-         Superficial to the lateral head of the gastrocnemius

 

PREFERRED RESPONSE: 5

 

DISCUSSION: At the level of tibial bone resection in total knee arthroplasty, the common peroneal nerve lies superficial to the lateral head of the gastrocnemius and is therefore protected by this structure.  In an MRI study of 60 knees, the mean distance from the bony posterolateral corner of the tibia to the nerve was 1.49 cm, with no distance less than 0.9 cm.  The distance from the bone to nerve was greater in larger legs.

 

REFERENCES: Clarke HD, Schwartz JB, Math KR, et al: Anatomic risk of peroneal nerve injury with the “pie crust” technique for valgus release in total knee arthroplasty.  J Arthroplasty 2004;19:40-44.

Anderson JE: Grant’s Atlas of Anatomy, ed 7.  Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-52, 4-53.

 

 

38.       Figures 24a through 24c show the coronal T₁-weighted, T₂-weighted fat-saturated, and T₁-weighted fat-saturated gadolinium MRI scans of the proximal thigh of a 52-year-old woman who reports a mass in the medial thigh and groin area.  She notes that the fullness has grown in size over the course of many months.  Based on these findings, what is the most likely diagnosis?

 

1-         Malignant fibrous histiocytoma

2-         Liposarcoma

3-         Synovial cell sarcoma

4-         Leiomyosarcoma

5-         Clear cell sarcoma

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The images show a complex, lobular lesion of the thigh that has signal characteristics that follow fat.  The size of the lesion, the areas of stranding within the mass, along with mild uptake on the gadolinium sequences and the mild edema within the lesion on the T₂-weighted image make liposarcoma the most likely diagnosis and simple intramuscular lipoma far less likely.  All other diagnoses listed would not follow fat characteristics shown on the MRI sequences.

 

REFERENCE: Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia.  Cancer Control 2001;8:221-231.

 

 

39.       The arrows in the axial T₁-weighted MRI scan shown in Figure 25 show which of the following structures?

 

1-         Ulnar artery and accompanying vein

2-         Deep and superficial branches of the ulnar nerve

3-         Radial and ulnar digital nerves to the little finger

4-         Palmar cutaneous and thenar motor branch of the median nerve

5-         Dorsal cutaneous branch of the ulnar nerve and common digital artery to the fourth web

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The arrows in the figure show the deep branch of the ulnar nerve (more radial) and the superficial branch of the ulnar nerve within Guyon’s canal.  Guyon’s canal is approximately 4 cm long beginning at the proximal extent of the transverse carpal ligament and ends at the aponeurotic arch of the hypothenar muscles.  Many structures comprise the boundaries of Guyon’s canal.  The floor, for example, consists of the transverse carpal ligament, the pisohamate and pisometacarpal ligaments, and the opponens digiti minimi.  Within Guyon’s canal, the ulnar nerve bifurcates into the superficial and deep branches.  The ulnar artery is immediately adjacent and radial to the ulnar nerve.  The median nerve is visualized within the carpal tunnel, and the palmar cutaneous branch is more radial to Guyon’s canal and volar to the carpal tunnel.  The radial and ulnar digital nerves to the little finger are branches off of the superficial branch of the ulnar nerve distal to its emergence from Guyon’s canal.  The ulnar artery is the round structure located radial to the branches of the ulnar nerve within Guyon’s canal.  Adjacent to the ulnar artery are two small veins.  The dorsal cutaneous branch of the ulnar nerve branches from the ulnar nerve in the distal forearm, well proximal to Guyon’s canal.  The common digital artery to the fourth web branches from the superficial palmar arch distal to Guyon’s canal.  The hook of the hamate is clearly seen in the figure, orienting the observer to the ulnar side of the wrist.

 

REFERENCES: Gross MS, Gelberman RH: The anatomy of the distal ulnar tunnel.  Clin Orthop Relat Res 1985;196:238-247.

Denman EE: The anatomy of the space of Guyon.  The Hand 1978;10:69-76.

 

 

40.     An 82-year-old man has had episodic right thigh pain after undergoing a total hip arthroplasty 10 years ago.  Initial postoperative radiographs are shown in Figures 26a and 26b, and current radiographs are shown in Figures 26c and 26d.  What is the most likely cause of his pain?

 

1-         Acetabular osteolysis

2-         Femoral osteolysis

3-         Acetabular loosening

4-         Femoral loosening

5-         Femoral and acetabular loosening

 

PREFERRED RESPONSE: 4

 

DISCUSSION: These radiographs are dominated by the subsidence of the femoral component.  There is also evidence of polyethylene wear and femoral osteolysis in the region of the greater trochanter.  There is no evidence of proximal (calcar) stress shielding, and there is a thick distal pedestal.  Engh and associates defined two major signs of osseointegration - the absence of radiolucent lines around the porous-surfaced portion of the implant and new bone bridging the gap between the endosteal surface and the porous portion of the implant.  Implant migration indicates failure of ingrowth.  Osteolysis is a periprosthetic loss of bone secondary to particulate debris and it is often clinically silent unless it is accompanied by pathologic fracture.  It is often globular.  Acetabular loosening is based on radiolucent lines and implant migration.  The current radiographs demonstrate subsidence of the stem with pedestal formation.

 

REFERENCES: Engh CA, Massin P, Suthers KE: Roentgenographic assessment of biologic fixation of porous-surface femoral components.  Clin Orthop Relat Res 1990;257:107-128.

Engh CA, Hooten JP, Zettl-Schaffer KF, et al: Evaluation of bone ingrowth in proximally and extensively porous-coated anatomic medullary locking prostheses retrieved at autopsy.  J Bone Joint Surg Am 1995;77:903-910.

 

 

41.     A 37-year-old patient with type I diabetes mellitus has a flexor tenosynovitis of the thumb flexor tendon sheath following a kitchen knife puncture wound to the volar aspect of the thumb.  Left unattended, this infection will likely first spread proximally creating an abscess in which of the following spaces of the palm?

 

1-         Central space

2-         Hypothenar space

3-         Carpal tunnel

4-         Posterior adductor space

5-         Thenar space

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Flexor tenosynovitis of the thumb flexor tendon sheath can spread proximally and form an abscess within the thenar space of the palm.  The flexor pollicis longus tendon does not pass through the central space of the palm or the hypothenar space of the palm.  The flexor pollicis longus tendon does pass through the carpal tunnel, but this is not a palmar space.  The three palmar spaces include the hypothenar space, the thenar space, and the central space.  The posterior adductor space would likely only be involved secondarily after spread from a thenar space infection.

 

REFERENCES: Hollinshead W: Anatomy for Surgeons: The Back and Limbs, ed 3.  Philadelphia, PA, Harper and Row, 1982, vol 3, pp 478-479.

Lee D, Ferlic R, Neviaser R: Hand infections, in Berger R, Weiss AP (eds): Hand Surgery.  Philadelphia, PA, Lippincott Williams & Wilkins, 2004, pp 1784-1785.

 

 

42.     What tendon is closest to an appropriately placed anterolateral portal for ankle arthroscopy?

 

1-         Peroneus brevis

2-         Extensor digitorum longus

3-         Extensor hallucis

4-         Tibialis anterior

5-         Peroneus tertius

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The appropriate placement of the anterolateral portal provides access to the lateral gutter of the joint while avoiding the superficial peroneal nerve.  The safest location for the portal is approximately 4 mm lateral to the peroneus tertius tendon, the closest of the tendons listed to the anterolateral portal.  Because the superficial peroneal nerve location is variable, attempts to visualize, palpate, or transilluminate the nerve are mandatory.

 

REFERENCE: Ogut T, Akgun I, Kesmezacar H, et al: Navigation for ankle arthroscopy: Anatomical study of the anterolateral portal with reference to the superficial peroneal nerve.  Surg Radiol Anat 2004;26:268-274.

 

 

43.       A 52-year-old woman reports nagging shoulder pain that has been present for months and is slowly progressive in nature.  The patient also reports nocturnal pain and notes that the pain is not activity related.  Figures 27a and 27b show the radiograph and bone scan, and Figures 27c through 27e show T₁-weighted, T₂-weighted, and gadolinium MRI scans, respectively.  Based on these findings, what is the most likely diagnosis?

 

1-         Aneurysmal bone cyst

2-         Enchondroma

3-         Plasmacytoma

4-         Giant cell tumor

5-         Chondrosarcoma

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The radiograph reveals a metaphyseal lesion with some stippled mineralization suggesting a chondroid tumor.  The bone scan shows increased uptake, beyond what is expected for a simple enchondroma, and beyond the limits of the lesion.  The MRI sequences shows a lobular lesion on the T₁- and T₂-weighted (bright on the T₂ sequence) images with inhomogeneous uptake of gadolinium; both findings are typical for a chondroid lesion.  The history of pain, the positive bone scan, the age of the patient, the size of the lesion, and the central location (enostotic) of the lesion all suggest a malignant cartilage tumor.  The images are not consistent with the other diagnoses.  In particular, plasmacytoma is more uniformly bright on T₂-weighted images and often has a negative bone scan.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 187-194.

Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA, WB Saunders, 2002, pp 3897-3904.

 

 

44.     Figure 28 shows an arthroscopic view of a right shoulder in the lateral position
through a posterior portal.  What is the area between structure B (biceps) and SS (subscapularis tendon)?

 

1-         Inferior glenohumeral ligament

2-         Superior glenohumeral ligament

3-         Rotator cuff interval

4-         Subscapularis recess

5-         Interior recess

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The rotator cuff interval is located between the supraspinatus and subscapularis and the biceps tendon is deep to the interval.  It is a triangular area where the base is the coracoid process and the apex is the transverse humeral ligament at the biceps sulcus.  Closure or tightening of this area is often helpful in patients with shoulder instability.  Conversely, this area is often contracted in patients with adhesive capsulitis and may need to be released.

 

REFERENCES: Selecky MT, Tibone JE, Yang BY, et al: Glenohumeral joint translation after arthroscopic thermal capsuloplasty of the rotator interval.  J Shoulder Elbow Surg 2003;12:139-143.

Harryman DT, Sidles JA, Harris SL, et al: The role of the rotator interval capsule in passive motion and stability of the shoulder.  J Bone Joint Surg Am 1992;74:53-66.

 

 

45.     New painful paresthesias near the site of the incision after an ulnar nerve transposition is the result of injury to what nerve?

 

1-         Medial antebrachial cutaneous

2-         Lateral antebrachial cutaneous

3-         Posterior antebrachial cutaneous

4-         Medial brachial cutaneous

5-         Dorsal antebrachial cutaneous

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Branches of the medial antebrachial cutaneous nerve can often be identified during routine ulnar nerve surgery crossing the medial aspect of the elbow.  It should be preserved to avoid development of painful paresthesias. 

 

REFERENCE: Dellon AL, Mackinnon SE: Injury to the medial antebrachial cutaneous nerve during cubital tunnel surgery.  J Hand Surg Br 1985;10:33-36.

 

 

46.     A 23-year-old man reports pain on the superior aspect of his right shoulder with repetitive overhead activities and when lying on his right side.  Figure 29 shows an axial MRI scan.  What is the most likely diagnosis based on the MRI findings?

 

1-         Osteoarthritis of the acromioclavicular joint

2-         Acromioclavicular joint separation

3-         Os acromiale

4-         Partial-thickness rotator cuff tear

5-         Superior labral tear

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Os acromiale represents a failure of fusion of the anterior acromial apophysis and has been reported in approximately 8% of the population.  Patients with a symptomatic os acromiale often report impingement-type symptoms with pain over the superior acromion, especially with overhead activities or sleeping.  When nonsurgical management is unsuccessful, surgical options include excision, open reduction and internal fixation, and arthroscopic decompression. 

 

REFERENCES: Kurtz CA, Humble BJ, Rodosky MW, et al: Symptomatic os acromiale.  J Am Acad Orthop Surg 2006;14:12-19.

Ortiguera CJ, Buss DD: Surgical management of the symptomatic os acromiale.  J Shoulder Elbow Surg 2002;11:521-528.

 

 

47.     Following a chevron bunionectomy performed through a dorsal approach, a patient has persistent numbness on the dorsal and medial aspect of the hallux.  What nerve has most likely been injured?

 

1-         Lateral plantar nerve

2-         Deep peroneal nerve

3-         Dural nerve

4-         Medial plantar nerve

5-         Dorsomedial cutaneous nerve of the hallux

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The dorsomedial cutaneous nerve of the hallux, which is a distal branch of the superficial peroneal nerve, supplies sensation to the skin on the dorsal and medial half of the hallux and may be injured during a chevron bunionectomy.  Injury to the nerve leads to particularly painful neuromas that directly impinge on the shoe.  For this reason, direct medial approaches are typically preferred for access to the medial aspect of the metatarsophalangeal joint.

 

REFERENCE: Miller SD: Dorsomedial cutaneous nerve syndrome: Treatment with nerve transection and burial into bone.  Foot Ankle Int 2001;22:198-202.

 

 

48.     A 74-year-old man reports progressive left hip pain with weight-bearing activities. 
A radiograph is shown in Figure 30.  What is the most likely underlying diagnosis?

 

1-         Infection

2-         Lymphoma

3-         Paget’s disease

4-         Massive bone infarct

5-         Old pelvic trauma

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiograph shows enlargement of the bone, coarse trabeculation, a blastic appearance, and thickening of the cortex, revealing the classic appearance of Paget’s disease in the sclerotic phase, the most common presentation.  While lymphoma may present as a blastic lesion, it will not have the same enlargement, coarse trabeculation of bone, and the significant sclerosis seen here.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 211-215.

Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA, WB Saunders, 2002, pp 1947-2000.

 

 

49.     The anatomy of the sciatic nerve as it exits the pelvis is best described as exiting
through the

 

1-         greater sciatic notch and passing between the inferior gemellus and the obturator externus.

2-         greater sciatic notch and passing between the piriformis and the superior gemellus.

3-         obturator foramen and passing between the obturator internus and the obturator externus.

4-         lesser sciatic notch and passing between the piriformis and the superior gemellus.

5-         lesser sciatic notch and passing between the superior gemellus and the inferior gemellus.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The sciatic nerve is formed by the roots of the lumbosacral plexus.  It exits the pelvis through the greater sciatic notch and appears in the buttock anterior to the piriformus.  From that point, the sciatic nerve passes posteriorly over the superior gemellus, obturator internus, inferior gemellus, and quadratus femoris before it passes deep to the biceps femoris.  The tendon of the obturator internus passes through the lesser sciatic notch. 

 

REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach.  Philadelphia, PA, JB Lippincott, 1984, p 347.

Anderson JE: Grant’s Atlas of Anatomy, ed 7.  Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-34, 4-36.

Hollingshead WH: Anatomy for Surgeons: The Back and Limbs, ed 2.  Hagerstown, MD, Harper & Row, 1969, pp 607-609.

 

 

50.     What complication is more likely following excessive medial retraction of the anterior covering structures during the anterolateral (Watson-Jones) approach to the hip?

 

1-         Numbness over the anterolateral thigh

2-         Ischemia to the leg

3-         Quadriceps weakness

4-         Abductor insufficiency

5-         Foot drop

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The femoral nerve is the most lateral structure in the anterior neurovascular bundle.  The femoral artery and vein lie medial to the nerve.  Retractors placed in the anterior acetabular lip should be safe, although neurapraxia of the femoral nerve may occur if retraction is prolonged or forceful leading to quadriceps weakness.  The femoral artery and nerve are well protected by the interposed psoas muscle.  Damage to the lateral femoral cutaneous nerve, causing numbness over the anterolateral thigh, can occur while developing the interval between the tensor fascia latae and sartorious in the anterior (Smith-Petersen) approach but less likely in the Watson-Jones approach.  Superior gluteal injury and accompanying abductor insufficiency may occur during excessive splitting of the glutei during the direct lateral (Hardinge) approach.  Foot drop secondary to sciatic injury is more common with a posterior exposure or posterior retractor placement.

 

REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach.  Philadelphia, PA, JB Lippincott, 1984, p 325.

Anderson JE: Grant’s Atlas of Anatomy, ed 7.  Baltimore, MD, Lippincott Williams & Wilkins, 1978, pp 4-17, 4-18.

 

 

51.     In the most common condition causing a winged scapula, which of the following nerves is affected?

 

1-         Long thoracic nerve

2-         Spinal accessory nerve

3-         Suprascapular nerve

4-         Dorsal scapular nerve

5-         Thoracodorsal nerve

 

PREFERRED RESPONSE: 1

 

DISCUSSION: A winged scapula is most often associated with Parsonage-Turner syndrome, a condition thought to be due to an inflammatory or immune-mediated mechanism.  Certain muscles are predisposed, particularly the serratus anterior muscle innervated by the long thoracic nerve. Other less common nerve lesions (eg, the spinal accessory and dorsal scapular nerves) may also cause winged scapulae. 

 

REFERENCES: Kline DG, Hudson AR: Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors.  Philadelphia, PA, WB Saunders, 1995.

van Alfen N, van Engelen BG: The clinical spectrum of neuralgic amyotrophy in 246 cases.  Brain 2006;129:438-450.

 

 

52.     A 17-year-old woman seen in the emergency department reports right knee pain and swelling that has progressively worsened over the past several weeks.  Radiographs are shown in Figures 31a and 31b.  What is the most likely diagnosis?

 

1-         Giant cell tumor

2-         Infection

3-         Chondrosarcoma

4-         Osteosarcoma

5-         Chondroblastoma

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiographs reveal a blastic lesion of the proximal tibial metaphysis with cortical destruction, mineralization extending into the soft tissue laterally, indistinct margins, and destruction of the normal trabecular pattern.  In this age group, with this aggressive appearance, osteosarcoma is the most likely diagnosis.  Chondroblastoma and giant cell tumor are generally geographic and lytic.  Chondrosarcoma is rare in this age group and would likely be a secondary lesion from an underlying chondroid tumor that is not present here.  Whereas infection can have a wide variety of appearances, it tends to be more lytic in the acute presentation.

 

REFERENCES: Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia.  Cancer Control 2001;8:221-231.

Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 175-186.

 

 

53.       A 26-year-old man has had hand pain and progressive swelling in the knuckle for the past several months.  He denies any trauma to the hand.  The ring finger metacarpophalangeal joint is tender, and there is loss of motion in the digit.  Figure 32a shows the radiograph and Figures 32b through 32d show the T₁-weighted, T₂-weighted, and gadolinium MRI scans, respectively.  What is the most likely diagnosis?

 

1-         Infection

2-         Giant cell tumor

3-         Nonossifying fibroma

4-         Enchondroma

5-         Osteosarcoma

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The radiograph reveals a subchondral lesion in the metacarpophalangeal joint that is lytic and expansile.  The MRI scans show a mass that is moderate in intensity on the
T₂-weighted image and has some gadolinium uptake.  There are no cystic components in this lesion.  The subchondral location and expansile nature are highly suggestive of giant cell tumor of bone.  A lesion with this appearance might also represent an aneurysmal bone cyst, given the amount of expansion present.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 113-118.

Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics.  Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

 

 

54.     Which of the following best describes the relationship of the median nerve to the flexor carpi radialis tendon just proximal to the carpal canal?

 

1-         Median nerve is volar and ulnar

2-         Median nerve is radial and volar

3-         Median nerve is dorsal and ulnar

4-         Median nerve is dorsal and radial

5-         Median nerve is volar and radial

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The median nerve has an intimate association with the palmaris longus and the flexor carpi radialis at the proximal aspect of the carpal canal.  The median nerve lies just ulnar and dorsal to the flexor carpi radialis tendon. 

 

REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2.  Philadelphia, PA, Lippincott-Raven, 1994, pp 118-131.

Henry A: Extensile Exposure, ed 3.  Edinburgh, UK, Churchill Livingstone, 1995, pp 100-107.

 

 

55.     Which of the following muscles has dual innervation?

 

1-         Pronator teres

2-         Flexor digitorum superificialis

3-         Coracobrachialis

4-         Latissimus dorsi

5-         Brachialis 

 

PREFERRED RESPONSE: 5

 

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

 

REFERENCE: Mahakkanukrauh P, Somsarp V: Dual innervation of the brachialis muscle. 
Clin Anat 2002;15:206-209.

 

 

56.     Figure 33a shows a line drawing of a normal hemipelvis.  The anterior acetabular rim is bold.  Figure 33b illustrates a hemipelvis with a crossover sign, which is indicative of what acetabular pathology?

 

1-         Low acetabular index

2-         Excessive acetabular retroversion

3-         Deficient anterior column bone

4-         Labral detachment

5-         Pelvic discontinuity

 

PREFERRED RESPONSE: 2

 

DISCUSSION: In a normal AP pelvis radiograph, the anterior rim of the acetabulum runs medially and distally, diverging from the posterior rim which runs much more vertically.  In excessive acetabular retroversion, the anterior rim (bold line in Figure 33b) and posterior rim start laterally, and as these lines progress medially and distally, the anterior line crosses the posterior line.  This predisposes to femoral acetabular impingement.

 

REFERENCES: Reynolds D, Lucas J, Klaue K: Retroversion of the acetabulum: A cause of hip pain.  J Bone Joint Surg Br 1999;81:281-288.

Espinosa N, Rothenfluh DA, Beck M, et al: Treatment of femoro-acetabular impingement: Preliminary results of labral refixation.  J Bone Joint Surg Am 2006;88:925-935.

 

57.     Which of the following structures is most vulnerable during a medial sesamoidectomy of the hallux?

 

1-         Abductor hallucis tendon

2-         Intermetatarsal ligament

3-         Plantar-medial cutaneous nerve of the hallux

4-         Dorsomedial cutaneous nerve of the hallux

5-         Crista

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The plantar-medial cutaneous nerve is at risk with the surgical approach to the medial sesamoid.  It is found directly underlying an incision made at the junction of the glabrous skin of the hallux and must be identified before the approach can proceed.  Transection will result in a painful neuroma that impinges on the plantar-medial surface of the toe and cause problems with shoe wear.  The only other structure that lies near the surgical field is the abductor hallucis tendon which lies dorsal to the incision.

 

REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2.  Philadelphia, PA, JB Lippincott, 1993, p 377.

 

 

58.     What structure is most at risk for injury from a retractor against the tracheoesophageal junction during an anterior approach to the cervical spine?

 

1-         Esophagus

2-         Trachea

3-         Superior laryngeal nerve

4-         Recurrent laryngeal nerve

5-         Sympathetic chain

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Although any of these structures can be injured by pressure from the medial blade of a self-retaining retractor, the recurrent laryngeal nerve runs cephalad in the interval between the esophagus and trachea and is vulnerable to pressure if caught between the retractor and an inflated endotracheal tube balloon. 

 

REFERENCES: Ebraheim NA, Lu J, Skie M, et al: Vulnerability of the recurrent laryngeal nerve in the anterior approach to the lower cervical spine.  Spine 1997;22:2664-2667.

Kilburg C, Sullivan HG, Mathiason MA: Effect of approach side during anterior cervical discectomy and fusion on the incidence of recurrent laryngeal nerve injury.  J Neurosurg Spine 2006;4:273-277.

 

 

59.     A 40-year-old man has had hip pain with increased activity over the past year.  Examination reveals restriction of motion and tenderness with combined hip flexion, adduction, and internal rotation.  An AP radiograph is shown in Figure 34.  What is the most likely diagnosis?

 

1-         Developmental dysplasia of the hip

2-         Osteonecrosis

3-         Perthes disease

4-         Pseudogout

5-         Femoral acetabular impingement

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Femoral acetabular impingement (FAI) is a pathologic entity leading to pain, reduced range of motion in flexion and internal rotation, and development of secondary arthritis of the hip.  There are two types of FAI:  cam impingement and pincher impingement.  Cam impingement is seen when a nonspherical femoral head produces a cam effect when the prominent portion to the femoral head rotates into the joint.  This mechanism produces shear forces that damage articular cartilage.  Radiographs reveal early joint degeneration and flattening of the head neck junction (the so-called “pistol grip deformity”) as seen in this image.  The pincher type of impingement involves abnormal contact between the femoral head neck junction and the acetabulum, in the presence of a spherical femoral head.

 

REFERENCES: Beall DP, Sweet CF, Martin HD, et al: Imaging findings of femoraoacetabular impingement syndrome.  Skeletal Radiol 2005;34:691-701.

Mardones RM, Gonzalez C, Chen Q, et al: Surgical treatment of femoroacetabular impingement: Evaluation of the effect of the size of the resection.  J Bone Joint Surg Am 2006;88:84-91.

 

 

60.     Figure 35 shows the radiograph of a 44-year-old woman with rheumatoid arthritis who reports neck pain.  Below what threshold number is surgical stabilization warranted for the interval shown by the arrow?

 

1-         8 mm

2-         10 mm

3-         12 mm

4-         14 mm

5-         16 mm

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The posterior atlanto-dens interval represents the space available for the spinal cord and a distance of less than 14 mm is predictive of neurologic progression, thus warranting consideration for fusion, even in the absence of symptoms.

 

REFERENCE: Boden SD, Dodge LD, Bohlman HH, et al: Rheumatoid arthritis of the cervical spine: A long-term analysis with predictors of paralysis and recovery.  J Bone Joint Surg Am 1993;75:1282-1297.

 

 

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

 

1-         teres major.

2-         teres minor.

3-         teres major and teres minor.

4-         latissimus dorsi.

5-         latissimus dorsi and teres major.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: While the most prominent functional deficit from axillary nerve lesions occurs from denervation of the deltoid, denervation of the teres minor also occurs.

 

REFERENCE: Hollinshead WH: Anatomy for Surgeons: The Back and Limbs.  New York, NY, Harper & Row, 1969.

 

 

62.     Figure 36 shows an AP radiograph of a 65-year-old man who reports activity-related groin pain.  History reveals that he underwent total hip arthroplasty 12 years ago.  What is the most likely diagnosis?

 

1-         Chondrosarcoma

2-         Infection

3-         Wear-induced osteolysis

4-         Corrosive effect due to dissimilar metals

5-         Metastatic tumor

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The AP radiograph demonstrates extensive periacetabular osteolysis.  The central hole eliminator has dissociated from the shell and migrated into a lytic defect in the ischium.  In a retrieval study, most periacetabular osteolytic lesions had a clear communication pathway with the joint space.  Lesions with communication to the joint via several pathways or through a central dome hole (as in this patient) were larger and more likely to be associated with cortical erosion.  Although periprosthetic tumors have been described, they are rare and particle-induced inflammation around a prosthesis does not seem to increase the risk for carcinogenesis. 

 

REFERENCES: Visuri T, Pulkkinen P, Paavolainen P: Malignant tumors at the site of total hip prosthesis: Analytic review of 46 cases.  J Arthroplasty 2006;21:311-323.

Bezwada HP, Shah AR, Zambito K, et al: Distal femoral allograft reconstruction for massive osteolytic bone loss in revision total knee arthroplasty.  J Arthroplasty 2006;21:242-248.

Kitamura N, Naudie DD, Leung SB, et al: Diagnostic features of pelvic osteolysis on computed tomography: The importance of communication pathways.  J Bone Joint Surg Am 2005;87:1542-1550.

 

 

63.     A 21-year-old man who was injured in a snowboarding accident 18 months ago now reports wrist pain.  An MRI scan is shown in Figure 37.  Based on the image findings, what is the most likely diagnosis?

 

1-         Preiser’s disease

2-         Scaphoid nonunion and osteonecrosis

3-         Kienbock’s disease

4-         Intraosseous ganglion

5-         Scapholunate dissociation

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The coronal MRI scan of the wrist shows the scaphoid.  There is a subtle fracture line with a step-off at the radial surface consistent with a nonunion.  The signal intensity is markedly different between the two fragments of the scaphoid.  This strongly suggests osteonecrosis.  Preiser’s disease is osteonecrosis typically involving most or all of the scaphoid.  Kienbock’s disease involves the lunate.  Intraosseous ganglia are easily diagnosed on MRI but typically have a fluid-filled area surrounded by denser bone in the periphery.  Scapholunate dissociation can be seen on MRI as an injury to the scapholunate ligament and widening of the scapholunate interval, neither of which is seen on this image.

 

REFERENCE: Perlik PC, Guilford WB: Magnetic resonance imaging to assess vascularity of scaphoid nonunions.  J Hand Surg Am 1991;16:479-484.

 

 

64.     An 82-year-old woman reports activity-related knee pain.  History reveals that she underwent total knee arthroplasty 16 years ago.  AP and lateral radiographs and a bone scan are shown in Figures 38a through 38c.  What is the most likely diagnosis?

 

1-         Particle-mediated osteolysis

2-         Metastatic carcinoma

3-         Stress shielding

4-         Septic joint

5-         Osteosarcoma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiographs reveal a large femoral metaphyseal lytic lesion with
well-defined borders.  Joint space narrowing medially is consistent with polyethylene wear. 
The most likely diagnosis is particle-mediated osteolysis.  Metastatic tumors and primary sarcomas adjacent to an arthroplasty are extremely rare.  In addition, malignant tumors and infection would more likely reveal a destructive lesion with poorly defined borders and increased uptake on a bone scan.  Stress shielding with massive bone loss has not been described in knee arthroplasty literature, although this entity has been observed in fully porous-coated femoral implants in total hip arthroplasty.

 

REFERENCES: Robinson EJ, Mulliken BD, Bourne RB, et al: Catastrophic osteolysis in total knee replacement: A report of 17 cases.  Clin Orthop Relat Res 1995;321:98-105.

Archibeck MJ, Jacobs JJ, Roebuck KA, et al: The basic science of periprosthetic osteolysis.  Instr Course Lect 2001;50:185-195.

Bugbee WD, Culpepper WJ, Engh CA Jr, et al: Long-term clinical consequences of stress-shielding after total hip arthroplasty without cement.  J Bone Joint Surg Am 1997;79:1007-1012.

 

 

65.     Which of the following tendons is found in the same dorsal compartment of the wrist as the posterior interosseous nerve?

 

1-         Extensor digiti minimi

2-         Extensor carpi radialis brevis

3-         Extensor pollicis longus

4-         Extensor indicis proprius

5-         Abductor pollicis longus

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The terminal branch of the posterior interosseous nerve is contained in the fourth dorsal compartment.  The contents of the various dorsal wrist compartments are as follows:

 

• 1^st Compartment: Abductor pollicis longus, extensor pollis brevis
• 2^nd Compartment: Extensor carpi radialis brevis, extensor carpi radialis longus
• 3^rd Compartment: Extensor pollicis longus
• 4^th Compartment: Extensor digitorum comminus, extensor indicus proprius, posterior interosseous nerve
• 5^th Compartment: Extensor digiti minimi
• 6^th Compartment: Extensor carpi ulnaris

 

The extensor indicis proprius is also contained in the fourth dorsal compartment.  The extensor digiti minimi is located in the fifth dorsal compartment.  The extensor carpi radialis brevis is located in the second dorsal compartment.  The extensor pollicis longus is located in the third dorsal compartment, and the abductor pollicis longus is located in the first dorsal compartment.

 

REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2.  Philadelphia, PA, Lippincott-Raven, 1994, pp 150-151.

Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders.  West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, p 60.

 

 

66.     Figures 39a and 39b show the MRI scans of a 25-year-old man with right shoulder pain.  Figure 39c shows the arthroscopic view from a posterior portal in the beach chair position.  What is the most likely diagnosis?

 

1-         Bankart lesion

2-         Superior labral tear

3-         Partial articular surface supraspinatus tear

4-         Partial bursal surface supraspinatus tear

5-         Full-thickness supraspinatus tear

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scans show coronal oblique and sagittal oblique views of a partial articular surface supraspinatus tear or tendon avulsion (PASTA lesion).  The arthroscopic view is a posterior portal of the glenohumeral joint viewing the articular surface of the supraspinatus.  These tears are a common source of shoulder pain and are often amenable to transtendon arthroscopic repair without detachment of the intact bursal surface. 

 

REFERENCES: Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the shoulder.  Am J Sports Med 2005;33:1088-1105.

McConville OR, Iannotti JP: Partial-thickness tears of the rotator cuff: Evaluation and management.  J Am Acad Orthop Surg 1999;7:32-43.

Burkhart SS: Arthroscopic management of rotator cuff tears, in McGinty JB (ed): Operative Arthroscopy, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 508-546.

 

 

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

 

1-         Middle genicular

2-         Medial inferior genicular

3-         Medial superior genicular

4-         Lateral superior genicular

5-         Inferior lateral genicular

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The middle genicular artery supplies the posterior capsule and intracapsular structures (anterior cruciate ligament, posterior cruciate ligament, posterior horns of the meniscus).  The medial and lateral inferior geniculates anastomose anteriorly to form a capillary network to supply the fat pad, synovial cavity, and patellar tendon.  The lateral superior and inferior genicular arteries supply the lateral retinaculum.

 

REFERENCES: Insall J, Scott WN: Anatomy, in Surgery of the Knee, ed 3.  Philadelphia, PA, Churchill Livingstone, 2001, pp 64-70.

Scapinelli R: Vascular anatomy of the human cruciate ligaments and surrounding structures.  Clin Anat 1997;10:151-162.

 

 

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

 

1-         A teres minor-splitting approach

2-         An infraspinatus-splitting approach

3-         Between the infraspinatus and teres minor

4-         Between the supraspinatus and infraspinatus

5-         In the rotator interval

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Using an infraspinatus-splitting incision allows for excellent exposure of the posterior capsule and minimizes the risk of injury to the axillary nerve which lies inferior to the teres minor in the quadrilateral space.

 

REFERENCES: Dreese J, D’Alessandro D: Posterior capsulorrhaphy through infraspinatus split for posterior instability.  Tech Shoulder Elbow Surg 2005;6:199-207.

Shaffer BS, Conway J, Jobe FW, et al: Infraspinatus muscle-splitting incision in posterior shoulder surgery: An anatomic and electromyographic study.  Am J Sports Med 1994;22:113-120.

Fuchs B, Jost B, Gerber C: Posterior-inferior capsular shift for the treatment of recurrent voluntary posterior subluxation of the shoulder.  J Bone Joint Surg Am 2000;82:16-25.

 

 

69.     Following ankle arthroscopy performed through a posterolateral portal, a patient
notes numbness on the lateral half of the heel pad of the foot.  What is the most likely injured structure?

 

1-         Sural nerve

2-         Lateral plantar nerve

3-         Lateral calcaneal nerve

4-         First branch of the lateral plantar nerve

5-         Deep peroneal nerve

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The lateral calcaneal nerve is a branch of the sural nerve that runs along the lateral border of the Achilles tendon to innervate the lateral heel pad. Ankle arthroscopy involves posterior portals that hug the Achilles tendon to avoid the main trunks of the sural nerve and tibial nerve; however, the lateral calcaneal branch remains potentially vulnerable.  The first branch of the lateral plantar nerve is actually a medial structure that partially innervates the plantar fascia and the abductor digiti quinti.  The deep peroneal nerve is anterior to the ankle.

 

REFERENCES: Sitler DF, Amendola A, Bailey CS, et al: Posterior ankle arthroscopy:
An anatomic study.  J Bone Joint Surg Am  2002;84:763-769.

Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2.  Philadelphia, PA, JB Lippincott, 1993, p 361.

 

 

70.     Figure 40 shows the MRI scan of a 23-year-old man with a history of recurrent anterior shoulder instability.  What is the most likely diagnosis?

 

1-         Humeral avulsion of the inferior glenohumeral ligament (HAGL lesion)

2-         Osseous Bankart lesion

3-         Perthes lesion

4-         Anterior labroligamentous periosteal sleeve avulsion (ALPSA lesion)

5-         Glenolabral articular disruption (GLAD lesion)

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The MRI scan shows an ALPSA lesion.  This is also known as a medialized Bankart with medial displacement of the torn anterior labrum.  During surgical stabilization, the labrum and periosteal sleeve must be mobilized and repaired laterally to reduce recurrent instability.  A Perthes lesion is a nondisplaced labral tear.  A GLAD lesion represents a nondisplaced anterior labral tear with an associated articular cartilage injury. 

 

REFERENCES: Neviaser TJ: The anterior labroligamentous periosteal sleeve avulsion lesion:
A cause of anterior instability of the shoulder.  Arthroscopy 1993;9:17-21.

Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the shoulder.  Am J Sports Med 2005;33:1088-1105.

 

 

71.     Figure 41 shows the MRI scan of a 38-year-old weightlifter.  What does the arrow on the MRI scan indicate?

 

1-         Biceps tear

2-         Pectoralis minor tear

3-         Pectoralis major tear

4-         Subscapularis tear

5-         Abscess formation

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Pectoralis major ruptures typically occur in avid weightlifters (often on supplements) and typically while bench-pressing.  Clinically there is significant discoloration/bruising over the pectoralis and into the axilla.  MRI helps confirm the diagnosis and may help determine if the tear is in the muscle belly or at the bone-tendon junction.

 

REFERENCES: Bal GK, Basamania CJ: Pectoralis major tendon ruptures: Diagnosis and treatment.  Tech Shoulder Elbow Surg 2005;6:128-134.

Aarimaa V, Rantanen J, Heikkila J, et al: Ruptures of the pectoralis major muscle.  Am J Sports Med 2004;32:1256-1262.

 

 

72.     Which of the following describes the correct proximal to distal progression of the annular and cruciform pulleys of the digits?

 

1-         A1, C1, A2, C2, A3, A4, C3

2-         A1, A2, A3, C1, C2, C3, A4

3-         A1, C1, C2, A2, A3, A4, C3

4-         A1, A2, C1, A3, C2, A4, C3

5-         A1, A2, A3, A4, C1, C2, C3

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The correct progression of the annular and cruciform pulley in the digits is A1, A2, C1, A3, C2, A4, C3.  The two cruciform pulleys are collapsible elements adjacent to the more rigid annular pulleys of the flexor tendon sheath.  This arrangement enables unrestricted flexion of the proximal interphalangeal joint.

 

REFERENCES: Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics, ed 2.  Philadelphia, PA, Lippincott-Raven, 1994, pp 176-186.

Strickland J: Flexor tendon-acute injuries, in Green D, Hotchkiss R, Pederson W (eds): Green’s Operative Hand Surgery, ed 4.  New York, NY, Churchill Livingstone, 1999, pp 1853-1855.

 

 

73.     A 75-year-old woman began a walking program 2 months after undergoing right total knee arthroplasty.  She had to stop the program after 4 weeks because of hindfoot pain and ankle swelling.  Radiographs are shown in Figures 42a and 42b.  What is the most likely diagnosis?

 

1-         Plantar fasciitis

2-         Osteochondral lesion of the talus

3-         Heel spur

4-         Insufficiency fracture of the calcaneus

5-         Chondrocalcinosis of the ankle joint

 

PREFERRED RESPONSE: 4

 

DISCUSSION: It is often tempting to assign a diagnosis of plantar fasciitis in patients with hindfoot pain.  In this patient, the radiographs confirm a diagnosis of a calcaneal insufficiency fracture.  The dense condensation of bone on the lateral view confirms the diagnosis.  There is no radiographic evidence of a heel spur, osteochondral lesions, or chondrocalinosis.

 

REFERENCES: Resnick D: Diagnosis of Bone and Joint Disorders, ed 3.  Philadelphia, PA,
WB Saunders, 1995, p 2591.

Kearon C: Natural history of venous thromboembolism.  Semin Vasc Med 2001;1:27-37.

Aldridge T: Diagnosing heel pain in adults.  Am Fam Physician 2004;70;332-338.

 

 

74.     Figure 43 shows an arthroscopic view of a right shoulder through a lateral portal in the beach chair position.  The arrow is pointing to what structure?

 

1-         Biceps tendon

2-         Coracohumeral ligament

3-         Superior glenohumeral ligament

4-         Middle glenohumeral ligament

5-         Inferior glenohumeral ligament

 

PREFERRED RESPONSE: 1

 

DISCUSSION: This view from the lateral portal shows a full-thickness rotator cuff tear.  The glenohumeral joint can be visualized through this tear.  The glenoid, labrum, and biceps tendon attaching to the superior aspect of the glenoid are easily viewed from this portal, and the arrow is pointing to the biceps tendon.  Arthroscopic rotator cuff repair can be performed while visualizing from this portal and using anterior and posterior working portals. 

 

REFERENCES: Mazzocca AD, Noerdlinger M, Cole B, et al: Arthroscopy of the shoulder: Indications and general principles of techniques, in McGinty JB (ed): Operative Arthroscopy,
ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 412-427.

Burkhart, SS: Arthroscopic management of rotator cuff tears, in McGinty JB (ed): Operative Arthroscopy, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 2003, pp 508-546.

 

 

75.     In Charcot-Marie-Tooth disease a progressive deformity develops in the foot.  Which functional muscles predominate in deformity formation?

 

1-         Posterior tibialis and peroneus longus

2-         Posterior tibialis and peroneus brevis

3-         Anterior tibialis and peroneus longus

4-         Anterior tibialis and peroneus brevis

5-         Extensor digitorum and anterior tibialis

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In Charcot-Marie-Tooth disease, the posterior tibialis and peroneus longus tendons remain strong, serving to invert the hindfoot and depress the first metatarsal head thus causing the cavovarus foot associated with this disease.  In contrast, the tibialis anterior and peroneus brevis are less functional and therefore cannot dorsiflex the ankle, elevate the first metatarsal, or evert the foot, contributing to the deformity.

 

REFERENCE: Herring JA (ed): Tachjians Pediatric Orthopedics, ed 3.  Philadelphia, PA,
WB Saunders, 2002, vol 2, p 984.

 

 

76.     Bleeding is encountered while developing the internervous plane between the tensor fascia lata and the sartorius during the anterior approach to the hip.  The most likely cause is injury to what artery?

 

1-         Ascending branch of the lateral femoral circumflex

2-         Superior gluteal

3-         Femoral

4-         Profunda femoris

5-         Medial femoral circumflex

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The ascending branch of the lateral femoral circumflex artery crosses the gap between the tensor fascia lata and the sartorious and must be identified and ligated or coagulated.  The other vessels are out of the field of dissection.

 

REFERENCES: Barrack RL, Booth RE Jr, Lonner JH, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction 3.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, p 312.

Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach.  Philadelphia, PA, JB Lippincott, 1984, p 304.

 

 

77.       A 36-year-old woman with familial neurofibromatosis has an enlarging mass in the posterior thigh.  The lesion has slowly increased in size and is now constantly painful.  Pressure on the mass causes dysesthesias in the foot.  Figures 44a through 44c show
T₁-weighted, STIR, and T₁-weighted fat-saturated gadolinium scans, respectively. 
Figure 44d shows a PET scan.  What does this lesion most likely represent?

 

1-         Peripheral nerve sheath tumor

2-         Malignant peripheral nerve sheath tumor

3-         Malignant fibrous histiocytoma

4-         Liposarcoma

5-         Synovial sarcoma

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The images reveal a large mass in the posterior thigh arising from the sciatic nerve.  The lesion is edematous, and the gadolinium image reveals rim enhancement, suggesting necrosis, given that the STIR image is not uniformly bright as would be seen in a cystic lesion.  The PET scan has increased uptake, in this case a standard unit value (SUV) of greater than 2.0.  These findings are all very suggestive of a malignant process.  The history of neurofibromatosis makes a malignant peripheral nerve sheath tumor, or neurofibrosarcoma, the most likely diagnosis.  The term “peripheral nerve sheath tumor” has replaced neurolemmoma and schwannoma.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 225-230.

Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA, WB Saunders, 2002, pp 4218-4235.

 

 

78.     In Dupuytren’s disease, the retrovascular cord typically displaces the radial proper digital nerve of the ring finger in what direction?

 

1-         Palmarly and radially

2-         Dorsally and ulnarly

3-         Palmarly and ulnarly

4-         Dorsally and radially

5-         Directly dorsal

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Retrovascular cords are common in Dupuytren’s disease and commonly require surgical treatment.  Nerve injury in Dupuytren’s surgery is an infrequent complication that occurs partly because the digital nerves can be displaced from their normal anatomic relationships by retrovascular cords.  The nerves are displaced superficially, toward the center of the digit (palmarly and ulnarly).  This displacement is typically seen at the level of the metacarpophalangeal joint.

 

REFERENCE: Rayan GM: Palmar fascial complex anatomy and pathology in Dupuytren’s disease.  Hand Clin 1999;15:73-86.

 

 

79.     Ganglion cysts about the wrist most commonly arise from what structure?

 

1-         First carpometacarpal joint

2-         Second carpometacarpal joint

3-         Scapholunate interosseous ligament

4-         Radioscaphocapitate ligament

5-         Capitohamate interosseous ligament

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Ganglion cysts are the most common mass or mass-like lesions seen in the hand and wrist.  They arise in a variety of locations, including synovial joints or tendon sheaths.  The most common location is the dorsal/radial wrist arising from the dorsal scapholunate interosseous ligament.

 

REFERENCE: Thornburg LE: Ganglions of the hand and wrist.  J Am Acad Orthop Surg 1999;7:231-238.

 

 

80.     A 60-year-old woman has activity-related hip pain after undergoing arthroplasty 5 years ago.  She has severe Parkinsonism and denies fevers or chills.  Radiographs are shown in Figures 45a and 45b.  What is the most likely cause of her pain?

 

1-         Chronic deep infection

2-         Heterotopic bone

3-         Femoral loosening

4-         Parkinsonism

5-         Acetabular loosening

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The radiographs reveal both cement debonding at the lateral shoulder of the prosthesis and a cement mantle fracture.  Both of these indicate a loose femoral component.  The radiographs show a stress fracture with reactive bone on the lateral femoral cortex in conjunction with the cement mantle fracture.  The acetabular component shows no evidence of loosening.  Heterotopic bone usually is not a source of pain when it is Brooker grade I, as in this case.  Parkinsonism generally is not associated with hip pain.

 

REFERENCES: Harris WH, McCarthy JC, O’Neill DA: Femoral component loosening using contemporary techniques of femoral cement fixation.  J Bone Joint Surg Am 1982;64:1063-1067.

Callaghan JJ, Rosenberg AG, Rubash H (eds): The Adult Hip.  Philadelphia, PA, Lippincott-Raven, 1998, pp 960, 1228-1229.

Maloney WJ, Schmalzreid T, Harris WH: Analysis of long-term cemented total hip arthroplasty retrievals.  Clin Orthop Relat Res 2002;405:70-78.

 

 

81.     A 15-year-old boy reports leg pain after being tackled during football practice.  Radiographs and a CT scan are shown in Figures 46a through 46c.  The patient has a pathologic fracture through what underlying lesion?

 

1-         Giant cell tumor

2-         Fibrous dysplasia

3-         Aneurysmal bone cyst

4-         Nonossifying fibroma

5-         Chondroblastoma

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The images show a lobulated, eccentric, well-marginated lesion that is typical of a nonossifying fibroma.  The lesion is slightly expansile, and the CT scan findings show that the lesion is very well marginated and the cortex is disrupted, which is a common finding.  None of the characteristics of this lesion is aggressive in nature.

 

REFERENCES: Menendez LR (ed): Orthopaedic Knowledge Update: Musculoskeletal Tumors.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 69-75.

Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics.  Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

 

 

82.     A 28-year-old man has left knee pain after a snow skiing accident.  The MRI scan shown in Figure 47 reveals which of the following?

 

1-         Osteosarcoma

2-         Bucket-handle medial meniscal tear

3-         Lateral collateral ligament tear

4-         Bone bruise

5-         Tibial spine avulsion

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Bone bruises are often noted on MRI after anterior cruciate and medial collateral ligament injuries.  The significance of these injuries awaits long-term follow-up studies.  The areas of increased signal on T₂-weighted images represent areas of acute hemorrhage and are secondary to microfractures of the adjacent medullary trabeculae.

 

REFERENCES: Wright RW, Phaneuf MA, Limbird TJ, et al: Clinical outcome of isolated subcortical trabecular fractures (bone bruise) detected on magnetic resonance imaging in knees.  Am J Sports Med 2000;28:663-667.

Faber KJ, Dill JR, Amendola A, et al: Occult osteochondral lesions after anterior cruciate ligament rupture: Six-year magnetic resonance imaging follow-up study.  Am J Sports Med 1999;27:489-494.

 

 

83.     Following application of a short leg cast, a patient reports a complete foot drop.  A compression injury of the peroneal nerve at the fibular neck is confirmed by electrical studies.  Which of the following muscles is expected to be the last to recover function during the ensuing months?

 

1-         Extensor digitorum longus

2-         Flexor digitorum longus

3-         Peroneus longus

4-         Extensor hallucis longus

5-         Tibialis anterior

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The recovery process from peroneal nerve palsy may take many months as axonal regrowth occurs.  Of the muscles listed, the extensor hallucis is innervated most distally by the peroneal nerve.  The flexor digitorum longus is innervated by the tibial nerve.

 

REFERENCE: Sarrafian SK: Anatomy of the Foot and Ankle, Descriptive, Topographic, Functional, ed 2.  Philadelphia, PA, JB Lippincott, 1993, p 364.

 

 

84.       A 28-year-old man reports knee stiffness, swelling, and a constant ache that is worse with activity.  Examination reveals an effusion, global tenderness, and warmth to the touch.  Flexion is limited to 110 degrees.  Figures 48a through 48d show sagittal T₁-weighted, sagittal T₂-weighted, axial T₁-weighted fat-saturated gadolinium, and axial gradient echo MRI scans.  Based on these findings, what is the most likely diagnosis?

 

1-         Infection

2-         Arthritis

3-         Synovial chondromatosis

4-         Pigmented villonodular synovitis (PVNS)

5-         Reactive synovitis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The MRI scans show multiple low-signal intensity lesions scattered throughout the knee, extending posteriorly inferior to the tibial plateau.  The low-signal intensity on both the T₁- and T₂-weighted images, the modest vascularity noted on the gadolinium image, and the “blooming” noted on the gradient echo image (ferrous-laden tissue) are all strongly suggestive of diffuse PVNS.  Whereas synovial chondromatosis can present as diffuse masses in the knee, they present as nodule masses that have low T₁- and high T₂-weighted signal characteristics.

 

REFERENCES: Resnick D (ed): Diagnosis of Bone and Joint Disorders.  Philadelphia, PA,
WB Saunders, 2002, pp 4241-4252.

Sanders TG, Parsons TW: Radiographic imaging of musculoskeletal neoplasia.  Cancer Control 2001;8:1-11.

 

 

85.     Figure 49 shows an acute axial MRI scan of a left knee.  What is the most likely diagnosis?

 

1-         Patellar tendon rupture

2-         Lateral dislocation of the patella

3-         Quadriceps tendon rupture

4-         Anterior cruciate ligament rupture

5-         Posterior cruciate ligament rupture

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The MRI scan shows bone bruises in the medial aspect of the patella and the lateral aspect of the lateral femoral condyle.  Both of these signs are typical for a lateral dislocation of the patella with spontaneous reduction.  In addition, there may be associated tearing of the medial retinaculum or distal aspect of the vastus medialis. 

 

REFERENCES: Elias DA, White LM, Fithian DC: Acute lateral patellar dislocation at MR imaging: Injury patterns of medial patellar soft-tissue restraints and osteochondral injuries of the inferomedial patella.  Radiology 2002;225:736-743.

Sanders TG, Miller MD: A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee.  Am J Sports Med 2005;33:131-148.

Miller TT: Magnetic resonance imaging of the knee, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 201-224. 

 

 

86.     Spontaneous entrapment of the posterior interosseous nerve most commonly occurs in which of the following locations?

 

1-         Lateral intermuscular septum

2-         Extensor carpi radialis brevis

3-         Arcade of Frohse

4-         Midsubstance of the supinator

5-         Leash of Henry

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The extensor carpi radialis brevis, supinator muscle, arcade of Frohse, and leash of Henry are potential sites of compression for the posterior interosseous nerve.  The most common location of spontaneous entrapment is the arcade of Frohse.  The lateral intermuscular septum is a site of compression for the radial nerve.

 

REFERENCE: Spinner RJ, Spinner M: Nerve entrapment syndromes, in Morrey BF: The Elbow and Its Disorders, ed 3.  Philadelphia, PA, WB Saunders, 2000, pp 839-862.

 

 

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

 

1-         Suboptimal cement technique

2-         Excessive activity level

3-         Oversized bipolar component

4-         Infection

5-         Osteoporosis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiographs demonstrate a rapid erosion of the bipolar component into the acetabulum.  Although acetabular erosion is more common with unipolar hip arthroplasties, it can occur with bipolar components.  Haidukewych and associates noted a very low erosion rate but none in the first 2 years.  The second finding on the radiographs is the linear radiolucency progressing from the joint toward the end of the stem at the cement-bone interface suggesting chronic infection or diffuse loosening.  The persistent pain since implantation also suggests chronic infection.  High activity levels and osteoporosis do not lead to acetabular erosion in the first 2 years after hemiarthroplasty.  While the cement technique is suboptimal, loosening and erosion should not be expected from this alone.  An oversized bipolar head would extrude and not erode.

 

REFERENCES: Haidukewych GJ, Israel TA, Berry DJ: Long-term survivorship of cemented bipolar hemiarthroplasty for fracture of the femoral neck.  Clin Orthop Relat Res 2002;403:118-126.

Lestrange NR: Bipolar hemiarthroplasty for 496 hip fractures.  Clin Orthop Relat Res 1990;251:7-19.

Callaghan JJ, Dennis DA, Paprosky WG, et al (eds): Orthopaedic Knowledge Update: Hip and Knee Reconstruction.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1995, p 158.

 

 

88.     What fibers of the anterior cruciate ligament tighten with extension of the knee?

 

1-         Anterolateral

2-         Anteromedial

3-         Posterolateral

4-         Posteromedial

5-         Posterior oblique

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The anterior cruciate ligament consists of two functional bundles: anteromedial and posterolateral.  During extension of the knee, the posterolateral bundle becomes taut.  In flexion, the anteromedial bundle is tight and the posterolateral bundle relaxes.  Traditionally, anterior cruciate ligament reconstruction primarily recreates the anteromedial bundle.  Recently, techniques for double bundle reconstruction have been described to recreate the normal anatomic relationship of the two bundles. 

 

REFERENCES: Girgis FG, Marshall JL, Monajem AS: The cruciate ligaments of the knee joint: Anatomical, functional and experimental analysis.  Clin Orthop Relat Res 1975;106:216-231.

Cha PS, Brucker PU, West RV, et al: Arthroscopic double-bundle anterior cruciate ligament reconstruction: An anatomic approach.  Arthroscopy 2005;21:1275. 

Clarke HD, Scott WN, Insall JN, et al: Anatomy, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 3-66. 

 

 

89.     In an effort to reduce costs, a limited MRI sequence is planned to detect a possible occult hip fracture.  What is the anticipated fracture signal?

 

1-         Bright on T₁ and T₂

2-         Dark on T₁ and T₂

3-         Dark on T₁, bright on T₂

4-         Bright on T₁, dark on T₂

5-         Enhancement by gadolinium

 

PREFERRED RESPONSE: 3

 

DISCUSSION: At present, radiologists perform multiple MRI images to rule out all possible diagnoses.  The ability to specify the anticipated changes on MRI should become more important as a means of reducing costs.  MRI is sensitive to changes in free water (or hemorrhage) and thus this will appear dark on T₁ and bright on T₂.

 

REFERENCES: Miller MD: Review of Orthopaedics, ed 3.  Philadelphia PA, WB Saunders, 2000, p 116.

Guanche CA, Kozin SH, Levy AS, et al: The use of MRI in the diagnosis of occult hip fractures in the elderly: A preliminary review.  Orthopedics 1994;17:327-330.

 

 

90.     When using the direct lateral (or Hardinge) approach for hip arthroplasty, three muscles are detached from the femur.  In addition to the vastus lateralis, they include the

 

1-         iliopsoas and sartorius.

2-         piriformis and obturator internus.

3-         gluteus maximus and tensor fascia lata.

4-         gluteus minimus and rectus femoris.

5-         gluteus medius and gluteus minimus.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: This approach is criticized for the episodic limp associated with the muscle detachment and reattachment.  Classically, two thirds of the gluteus medius is detached as a sleeve with the vastus lateralis.  This exposes the gluteus minimus and the ligament of Bigelow.  These must also be detached to allow dislocation of the hip and osteotomy of the femoral neck.  The rectus femoris lies medially and anteriorly and does not need to be addressed.  The piriformis and obturator internus are exposed during the posterior approach.  Neither the gluteus maximus nor tensor fascia lata attach to the anterior femur.  The sartorius and iliopsoas are not exposed during this dissection.

 

REFERENCES: Hoppenfeld S, deBoer P (eds): Surgical Exposures in Orthopaedics: The Anatomic Approach.  Philadelphia, PA, JB Lippincott, 1984, pp 333-335.

Hardinge K: The direct lateral approach to the hip.  J Bone Joint Surg Br 1982;64:17-19.

 

 

91.     Figure 51 shows an arthroscopic view of the patellofemoral joint from an inferolateral portal.  The arrow points to which of the following structures?

 

1-         Loose body

2-         Plica

3-         Displaced meniscus tear

4-         Torn retinaculum

5-         Osteochondral defect

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Synovial folds or plicae are the result of incomplete or partial resorption of the synovial membranes during fetal development of the knee.  The arthroscopic view shows a medial patellar plica, which has been noted in 5% to 55% of all individuals but becomes symptomatic in only a small number of patients.  Symptoms may include crepitus, pain, snapping, and swelling and often respond to nonsurgical management. 

 

REFERENCES: Clarke HD, Scott WN, Insall JN: Anatomic aberrations, in Insall JN, Scott WN (eds): Surgery of the Knee, ed 4.  Philadelphia, PA, Churchill Livingstone, 2006, vol 1, pp 67-85. 

Patel D: Plica as a cause of anterior knee pain.  Orthop Clin North Am 1986;17:273-277.

 

 

92.     In a juvenile Tillaux ankle fracture, what ligament causes the displacement of the
fracture fragment?

 

1-         Anterior tibiofibular

2-         Posterior tibiofibular

3-         Deltoid

4-         Calcaneofibular

5-         Talonavicular

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The juvenile Tillaux ankle fracture usually occurs because the lateral half of the distal tibial physis remains open.  During an external rotational force, the anterior tibiofibular ligament holds the lateral tibial epiphysis, separating it through at the junction of the middle closed physis and lateral open physis.

 

REFERENCE: Green NE, Swiontkowski MF: Skeletal Trauma in Children, ed 3.  Philadelphia, PA, WB Saunders, 2003, p 529. 

 

 

93.     When harvesting an iliac crest bone graft from the posterior approach, what anatomic structure is at greatest risk for injury if a Cobb elevator is directed too caudal?

 

1-         Sciatic nerve

2-         Cluneal nerves

3-         Inferior gluteal artery

4-         Superior gluteal artery

5-         Sacroiliac joint

 

PREFERRED RESPONSE: 4

 

DISCUSSION: If a Cobb elevator is directed caudally while stripping the periosteum over the iliac wing, it will encounter the sciatic notch.  Although this puts the sciatic nerve at risk, the first structure encountered is the superior gluteal artery.  Because it is tethered at the superior edge of the notch, it is very vulnerable to injury and can then retract inside the pelvis, making it difficult to obtain hemostasis.  The inferior gluteal artery exits the sciatic notch below the piriformis and is more protected.  The cluneal nerves are at risk only if the incision extends too anteriorly, and the sacroiliac joint can be entered while harvesting the graft.

 

REFERENCES: Banwart JC, Asher MA, Hassanein RS: Iliac crest bone graft harvest donor site morbidity: A statistical evaluation.  Spine 1995;20:1055-1060.

Shin AY, Moran ME, Wenger DR: Superior gluteal artery injury secondary to posterior iliac crest bone graft harvesting: A surgical technique to control hemorrhage.  Spine 1996;21:1371-1374.

 

 

94.     Figures 52a and 52b show the radiographs of a left proximal femoral lesion noted serendipitously following minor trauma to the left hip.  The patient has no thigh pain and is fully active without limitation.  What is the most likely diagnosis of this bony lesion?

 

1-         Chondroblastoma

2-         Enchondroma

3-         Giant cell tumor

4-         Fibrous dysplasia

5-         Osteoblastoma

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiographs reveal a geographic lesion of the proximal femur with the classic “ground glass” appearance noted in fibrous dysplasia.  This intramedullary lesion is modestly expansile, demonstrates some minimal cortical thinning, and has no aggressive features. Chondroblastoma, giant cell tumor, and osteoblastoma are more lytic in appearance, and the location is not typical for giant cell tumor or chondroblastoma.  While enchondroma may be considered, the uniform ground glass appearance, lack of punctuate mineralization, and distinct margination of the lesion make that diagnosis less likely.

 

REFERENCE: Parsons TW: Benign bone tumors, in Fitzgerald R Jr, Kaufer H, Malkani A (eds): Orthopaedics.  Philadelphia, PA, Mosby International, 2002, pp 1027-1035.

 

 

95.     Figure 53 shows the arteriogram of a 45-year-old man who has severe vasculitis.  What do the findings show?

 

1-         A patent ulnar artery and deep palmar arch

2-         A patent ulnar artery and superficial palmar arch

3-         A patent radial artery and deep palmar arch

4-         A patent radial artery and superficial palmar arch

5-         A patent radial artery and an ulnar artery aneurysm

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The arterial supply to the hand is abundant and normally duplicated.  The deep palmar arch as shown in this arteriogram typically receives its primary contribution from the radial artery which travels deep to the first dorsal compartment tendons and then returns to the volar aspect of the palm through the first web space.  The superficial palmar arch receives its supply from the ulnar artery and is not visualized in this patient.

 

REFERENCE: Cooney WP, Linscheid RL, Dobyns JH (eds): The Wrist: Diagnosis and Operative Treatment.  Philadephia, PA, Mosby-Year Book, 1998, p 110.

 

 

96.     A patient with a left-sided C6-7 herniated nucleous pulposis would likely have which of the following constellation of findings?

 

1-         Pain into the thumb, triceps weakness, and loss of triceps reflex

2-         Middle finger numbness, wrist extensor weakness, diminished brachioradialis reflex

3-         Thumb numbness, wrist extensor weakness, diminished brachioradialis reflex 

4-         Middle finger numbness, triceps weakness, and loss of biceps reflex

5-         Middle finger numbness, triceps weakness, and loss of triceps reflex

 

PREFERRED RESPONSE: 5

 

DISCUSSION: A C6-7 herniation affects the C7 root.  The C7 root has the middle finger as its predominant sensory distribution.  Its motor function is the triceps, wrist extension, and finger metacarpophalangeal extension.  The reflex is the triceps.

 

REFERENCES: Magee D: Principles and concepts, in Orthopedic Physical Assessment, ed 3.  Philadelphia, PA, WB Saunders, 1997, pp 1-18.

An H: History and physical examination of the spine, in Principles and Techniques of Spine Surgery.  Baltimore, MD, Lippincott Williams & Wilkins, 1998, pp 91-101.

 

 

97.     Which of the following muscle tendons inserts just lateral to the long head of biceps tendon on the proximal humerus?

 

1-         Teres major

2-         Latissimus dorsi

3-         Short head of the biceps

4-         Pectoralis major

5-         Subscapularis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The pectoralis major insertion is just lateral to the long head of the biceps tendon.  Medial to the biceps is the insertion for the teres major and latissimus dorsi.  The short head of the biceps originates on the coracoid process.  The subscapularis inserts on the lesser tuberosity just medial to the biceps. 

 

REFERENCE: Bal GK, Basamania CJ: Pectoralis major tendon ruptures: Diagnosis and treatment.  Tech Shoulder Elbow Surg 2005;6:128-134.

 

 

98.     A 4-month-old infant is unable to flex her elbow as a result of an obstetrical brachial plexus palsy.  This most likely illustrates a predominate injury to what structure?

 

1-         C4

2-         Upper trunk

3-         Posterior cord

4-         Lateral cord

5-         Musculocutaneous nerve

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Erb’s palsy is the most common form of obstetrical plexus palsy resulting in C5, C6, or upper trunk deficits.  This causes loss of shoulder abduction and elbow flexion.  The biceps muscle and the brachialis muscles are predominately responsible for flexion of the elbow.  Each of these muscles is innervated by individual branches of the musculocutaneous nerve which are supplied predominately by axons from the C6 nerve root and the upper trunk of the brachial plexus.

 

REFERENCES: Netter F: The Ciba Collection of Medical Illustrations: The Musculoskeletal System, Part 1: Anatomy, Physiology and Metabolic Disorders.  West Caldwell, NJ, Ciba-Geigy Corporation, 1987, vol 8, pp 28-29.

Wolock B, Millesi H: Brachial plexus-applied anatomy and operative exposure, in Gelberman RH (ed): Operative Nerve Repair and Reconstruction.  Philadelphia, PA, JB Lippincott, 1991,
pp 1255-1272.

Zancolli E: Reconstructive surgery in brachial plexus sequelae, in Gupta A, Kay S, Scheker L (eds): The Growing Hand.  London, England, Mosby, 1999, p 807.

 

 

99.     Following a fall from a height of 5 feet, a patient reports pain along the lateral border of the foot.  The CT scan shown in Figure 54 indicates what pathology?

 

1-         Impaction injury of the cuboid

2-         Retracted os peroneum

3-         Fifth metatarsal avulsion fracture

4-         Avulsion injury of the bifurcate (Y) ligament

5-         Lisfranc injury

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The CT scan reveals an avulsion of the dorsal beak of the anterior process of the calcaneus.  This common fracture is an avulsion of the origin of the bifurcate ligament, which runs from the anterior calcaneal process to both the cuboid and the lateral aspect of the navicular.  An inversion mechanism is common, and the fracture is often missed in evaluation for a suspected ankle sprain.  MRI may be useful in the diagnosis of these occult injuries, and suspicion should be present when tenderness exists over the superior portion of the anterior process of the calcaneus.

 

REFERENCE: Robbins MI, Wilson MG, Sella EJ: MR imaging of anterosuperior calcaneal process fractures.  Am J Roentgenol 1999;172:475-479.

 

 

100.   The patient in Figure 55 is actively attempting to make a fist.  This clinical scenario suggests which of the following anatomic lesions?

 

1-         Median nerve lesion in the arm

2-         Radial nerve lesion in the arm

3-         Anterior interosseous nerve syndrome

4-         Posterior interosseous nerve syndrome

5-         Median neuropathy at the wrist

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The clinical presentation is characteristic of a high median nerve palsy.  When trying to make a fist, the patient is unable to flex the thumb and index fingers due to paralysis of flexion of the distal interphalangeal joint of the thumb and the distal and proximal interphalangel joints of the index finger.  This hand attitude differs from the anterior interosseous nerve lesion in which loss of distal interphalangeal joint flexion is seen in the thumb, index, and middle fingers.  Posterior interosseous nerve syndrome presents with dropped fingers at the metacarpophalangeal joints with wrist extension in radial deviation.  Wrist and finger drop is the typical posture of patients with radial nerve lesions.

 

REFERENCE: Kline DG, Hudson AR: Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors.  Philadelphia, PA, WB Saunders, 1995, p 189.

 

 

101.   You are interested in learning a new technique for minimally invasive total knee arthroplasty.  The Keyhole Genuflex system seems appealing to you because the instrumentation comes with wireless controls.  Which of the following represents an acceptable arrangement?

 

1-         The local Keyhole representative has invited you and your spouse out to dinner at a local restaurant to discuss your interest in their new minimally invasive total knee system, the Keyhole Genuflex knee.

2-         Keyhole has offered to pay your tuition to attend a CME course sponsored by the American Association of Hip & Knee Surgeons where both the Genuflex and the competing Styph total knee are discussed and demonstrated.

3-         Keyhole will pay your expenses to attend a workshop, in Phoenix at their company headquarters, to learn how to implant the Genuflex knee and to see how the implant is manufactured and tested.

4-         Keyhole will pay you $500 for each knee that you implant if you switch from your current total knee system.

5-         After you have implanted 25 Genuflex knees, Keyhole will list you on their website as a consultant, pay you a consulting fee of $5,000 per year, and invite you to a golf tournament for their consultants at a resort.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Both the AAOS and AdvaMed, the medical device manufacturer's trade organization, have written guidelines that address potential conflicts of interest regarding interactions between physicians and manufacturer's representatives when it comes to patients' best interest.  The AAOS feels that the orthopaedic profession exists for the primary purpose of caring for the patient and that the physician-patient relationship is the central focus of all ethical concerns.  When an orthopaedic surgeon receives anything of significant value from industry, a potential conflict of interest exists.  The AAOS believes that it is acceptable for industry to provide financial and other support to orthopaedic surgeons if such support has significant educational value and has the purpose of improving patient care.  All dealings between orthopaedic surgeons and industry should benefit the patient and be able to withstand public scrutiny.  A gift of any kind from industry should in no way influence the orthopaedic surgeon in determining the most appropriate treatment for his or her patient.  Orthopaedic surgeons should not accept gifts or other financial support with conditions attached.  Subsidies by industry to underwrite the costs of educational events where CME credits are provided can contribute to the improvement of patient care and are acceptable.  A corporate subsidy received by the conference's sponsor is acceptable; however, direct industry reimbursement for an orthopaedic surgeon to attend a CME educational event is not appropriate.  Special circumstances may arise in which orthopaedic surgeons may be required to learn new surgical techniques demonstrated by an expert or to review new implants or other devices on-site.  In these circumstances, reimbursement for expenses may be appropriate. 

 

REFERENCES: AAOS Standard of Professionalism -Orthopaedist -Industry Conflict of Interest (Adopted 4/18/07), Mandatory Standard numbers 6, 9, 12-15.  http://www3.aaos.org/member/profcomp/SOPConflictsIndustry.pdf

The Orthopaedic Surgeon’s Relationship with Industry, in Guide to the Ethical Practice of Orthopaedic Surgery, ed 7.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2007.  http://www.aaos.org/about/papers/ethics/1204eth.asp

AdvaMed Code of Ethics on Interactions with Health Care Professionals 2005.  http://www.advamed.org/MemberPortal/searchresults.htm?query=Advamed%20Code%20of%20Ethics%20on%20Interactions%20with%20Health%20Care%20Professionals%202005