FREE Orthopedics MCQS 2022 1601-1650.

1601. (3872) Q4-7655:

Types of nerve tissues surrounding the axons include all of the following EXC EPT:

1) Endoneurium

3) Perineurium

2) Hyponeurium

5) Epineurium

4) Mesoneurium

The structures surrounding the axons and Schwann cells include the endoneurium, perineurium, and epineurium. The mesoneurium is an adventitial layer in addition.

 

■Correct Answer:Hyponeurium

1602. (3873) Q4-7656:

The Seddon grades of nerve injury include all of the following EXC EPT:

1) Neuropraxia

3) Neurotmesis

2) Axonotmesis

4) Schwann cell disruption

Neuropraxic injuries are stretch injuries to the nerve. Axonotmetic injury involves a more severe injury with loss of continuity of axons, and connective tissue elements remain intact. Neurotmesis is a complete nerve discontinuity. Schwann cell disruption occurs in neurotmesis but is not among the grades of Seddon nerve injury.

 

■Correct Answer:Schwann cell disruption

1603. (3874) Q4-7657:

Younger age is associated with worse outcomes with nerve repair.

1) True

2) False

Younger age is associated with improved functional outcome after nerve repair, particularly regarding sensory recovery. 

■Correct Answer:False

1604. (3875) Q4-7658:

Optimum conditions for nerve healing after direct repair include:

1) Gapping at suture repair site

3) Early motion of extremity

2) Tension-free repair

5) lacing sutures through the endoneurium to increase repair strength

4) Preservation of all tissue whether devitalized or viable

Tension-free repair is the optimal technique to improve the potential for nerve recovery. Gapping, failure to splint to prevent tension on the nerve with motion, and failure to excise scarred or devitalized nerve tissue are impairments to successful nerve repairs. Suture repairs through the deep nerve segments can damage the axons. Sutures should be placed through the epineurium or, in a grouped fascicular repair, through the perineurium around the fascicles.

 

■Correct Answer:Tension-free repair

1605. (3876) Q4-7659:

Gunshot or missile wounds can frequently cause neuropraxic injuries to peripheral nerves.

1) True

2) False

Missile wounds can cause a blast stretch injury to peripheral nerves and may recover with observation. 

■Correct Answer:True

1606. (3887) Q4-7766:

The anatomic location of the pathologic lesion of lateral epicondylitis is the:

1) Extensor carpi radialis longus (EC RL)

3) Extensor digitorum longus (EDL)

2) Extensor carpi radialis brevis (EC RB)

5) Annular ligament

4) Extensor digitorum communis (EDC )

While the EC RL and EDL can sometimes be involved, the primary location of most cases of tennis elbow show characteristic changes at the origin of the EC RB.

 

■Correct Answer:Extensor carpi radialis brevis (EC RB)

1607. (3888) Q4-7767:

Which of the following injectable substances have shown benefit in the treatment of lateral epicondylitis:

1) C orticosteroids

3) Botulinum toxin

2) Autologous blood

5) All of the above

4) None of the above

All of these substances have been shown to have efficacy in the treatment of tennis elbow. However, placebo saline injections have also been proven to add some benefit compared to no treatment.

 

■Correct Answer:All of the above

1608. (4068) Q4-7768:

The nerve most at risk during arthroscopic debridement of lateral epicondylitis is the:

1) Ulnar nerve

3) Anterior interosseous nerve

2) Median nerve

5) Musculocutaneous nerve

4) Posterior interosseous nerve

While the ulnar nerve is most at risk during elbow arthroscopy in general, debridement of the lateral capsule posterior to the midpoint of the radiocapitellar joint places the posterior interosseous branch of the radial nerve at risk.

 

■Correct Answer:Posterior interosseous nerve

1609. (3889) Q4-7769:

C ommon concomitant intra-articular pathology that can be found and addressed at arthroscopy for lateral epicondylitis include all of the following, except:

1) Synovial plica

3) Synovitis

2) Loose body

5) C hondral lesion

4) Medial epicondylitis

While all of the other answers are intra-articular lesions that have been reported in elbow arthroscopies, medial epicondylitis is an extra-articular condition and must be addressed in an open fashion given the proximity of the ulnar nerve.

 

■Correct Answer:Medial epicondylitis

1610. (3890) Q4-7770:

Arthroscopic resection/debridement posterior to the midline of the radio-capitellar joint can result in damage to           ligament, resulting in               instability.

1) Lateral collateral; valgus

3) Ulnar collateral; posterolateral rotatory

2) Ulnar collateral; valgus

5) Lateral collateral; posterolateral rotatory

4) Annular; posterolateral rotatory

Resection posterior to the midpoint of the radiocapitellar joint can result in damage to the lateral collateral ligament and subsequent development of posterolateral rotator instability.

 

■Correct Answer:Lateral collateral; posterolateral rotatory

1611. (3911) Q4-7791:

The muscle that flexes the interphalangeal joint of the thumb is innervated by which roots of the brachial plexus:

1) C 5, C 6

3) C 6, C 7, C 8

2) C 5, C 6, C 7

5) C 7, C 8, T1

4) C 5, C 6, C 7, C 8, T1

The interphalangeal joint of the thumb is flexed secondary to actions of the flexor pollicis longus (FPL). The FPL is innervated by the anterior interosseous nerve, which is the longest branch of the median nerve. The median nerve is formed by the lateral (roots C 5, C 6, and C 7) and medial (roots C 8 and T1) cords of the brachial plexus.

 

■Correct Answer:C 5, C 6, C 7, C 8, T1

1612. (3912) Q4-7792:

The anterior interosseous nerve (AIN) originates from the median nerve at what distance from the medial epicondyle:

1) 6 cm distal

3) 6 cm proximal

2) 10 cm proximal

5) At the medial epicondyle

4) 10 cm distal

The AIN, the largest branch of the median nerve, originates 5 cm to 8 cm distal to the medial epicondyle from the posteroradial aspect of the median nerve just distal to the proximal border of the superficial head of the pronator teres.

 

■Correct Answer:6 cm distal

1613. (3913) Q4-7793:

A 30-year-old right-hand dominant woman presents to the emergency department with a 6-week history of difficulty writing and pain after playing tennis. She also reports a recent inability to abduct and adduct her fingers. What is the mechanism of her symptoms:

1) Writerâs cramp or focal dystonia

3) Martin-Gruber interconnection

2) Riche-C annieu anastamosis

5) C arpal tunnel syndrome

4) Ulnar neuropathy

Approximately 17% of the population has a Martin-Gruber interconnection, and 50% of these patients may show additional denervation of normally ulnar nerve-innervated intrinsic muscles. The Martin-Gruber anomaly is a motor neural connection between the anterior interosseous nerve and ulnar nerves that is located adjacent to the ulnar artery in the proximal forearm.

 

■Correct Answer:Martin-Gruber interconnection

1614. (3914) Q4-7794:

What is the innervation of the indicated muscle in the image (Slide):

1) Median nerve

3) Radial nerve

2) Anterior interosseous nerve

5) Posterior interosseous nerve

4) Ulnar nerve

The arrow in the photograph (Slide) is pointing to the pronator teres â one of the most common sites for compression of the anterior interosseous nerve. The pronator teres is innervated by the median nerve.

 

■Correct Answer:Median nerve

1615. (3915) Q4-7795:

Sites of potential compression of the median nerve include all of the following except:

1) Pronator teres

3) Pisohamate ligament

2) Transverse carpal ligament

5) Mass in carpal canal (e.g., lipoma)

4) Supracondylar process

Around the elbow, the median nerve may be compressed by the pronator teres (causing either anterior interosseous nerve syndrome or pronator syndrome) or the ligament of Struthers originating from a supracondylar process (causing pronator syndrome). In the wrist, the median nerve may be compressed by the transverse carpal ligament or a mass within the carpal canal. The ulnar nerve, not the median nerve, can be compressed by the pisohamate ligament.

 

■Correct Answer:Pisohamate ligament

1616. (3938) Q4-8126:

What position of the wrist most commonly produces scaphoid fractures:

1) Wrist flexion and radial deviation

3) Wrist flexion and ulnar deviation

2) Wrist extension and radial deviation

5) C lenched fist and wrist flexion

4) Wrist extension and ulnar deviation

Frykman performed biomechanical studies to evaluate the wrist position in falls that produce scaphoid fractures. The results showed that wrist extension greater than 90° and radial deviation consistently resulted in fracture of the scaphoid.

 

■Correct Answer:Wrist extension and radial deviation

1617. (3939) Q4-8127:

Which of the following blood vessels supplies the majority of the scaphoid:

1) Superficial palmar branch of the radial artery (volar)

3) Dorsal carpal branch of the radial artery (dorsal)

2) Radial artery

5) 3,4 intracompartmental supra-retinacular artery (3,4-IC SRA)

4) Ulnar artery

Gelberman and Menon used injection studies to demonstrate that the majority of scaphoid blood flow stems from branches of the radial artery entering the scaphoid at the distal pole. Of these, the branch entering the dorsal ridge supplies 70% to 80% of the intraosseous vascularity of the scaphoid bone. The proximal pole is completely dependent on the intraosseous blood supply and is vulnerable to avascular necrosis when fracture disrupts this vascular source.

 

■Correct Answer:Dorsal carpal branch of the radial artery (dorsal)

1618. (3940) Q4-8128:

During a posterior (dorsal) approach to percutaneous screw fixation for a scaphoid fracture, many structures are close to the guidewire insertion location and are at risk for injury. Which of the following structures is the closest to the guidewire insertion location according to a recent cadaveric study:

1) Posterior interosseous nerve

3) Extensor indicis proprius

2) Extensor digitorum communis to the index

5) Extensor digitorum communis to the index and posterior interosseous nerve

4) Extensor carpi radialis brevis

Adamany and colleagues performed a cadaveric study to evaluate the dorsal structures at risk with truly percutaneous headless screw placement for scaphoid fractures. They noted that the posterior interosseous nerve and the extensor digitorum communis to the index finger were an average of 2.2 mm from the guidewire and therefore at greatest risk from this approach.

 

■Correct Answer:Extensor digitorum communis to the index and posterior interosseous nerve

1619. (3941) Q4-8129:

Which of the following is a concerning risk factor for a dorsal open approach to the scaphoid:

1) Damage to tenous blood supply of the scaphoid

3) Damage to scapho-trapezial-trapezoid  joint during the approach

2) Difficulty of central screw placement

5) njury to the higher rate of infection

4) Damage to the lunatotriquetral (LT) ligament

The dorsal approach is advantageous in obtaining central screw placement. The scapho-trapezial-trapezoid  joint is at risk during a volar approach, not a dorsal approach, and infection has not been shown to occur more frequently in one approach over the

other. The LT ligament is not seen in either approach. The risk of the open dorsal approach is compromise of the main blood supply to the scaphoid, entering through the dorsal ridge.

 

■Correct Answer:Damage to tenous blood supply of the scaphoid

1620. (3942) Q4-8130:

A volar approach to the scaphoid is ideal in which of the following fractures:

1) Proximal pole fractures

3) C omminuted scaphoid fractures

2) Distal pole fractures

5) Scaphoid fracture with associated scapholunate ligament tear

4) Avascular necrosis of the scaphoid proximal pole

The volar approach to the scaphoid is optimal in distal pole fractures because it allows direct visualization of the fracture line and exact reduction and fixation. A volar approach is not recommended for fractures or avascular necrosis of the proximal pole, where dorsal screw placement is best. Scapholunate ligament tears are generally repaired from a dorsal approach because the ligament is stoutest dorsally.

 

■Correct Answer:Distal pole fractures

1621. (3944) Q4-8195:

Which finger is most commonly involved in a flexor digitorum profundus (FDP) avulsion injury:

1) Index

3) Ring

2) Middle

5) Thumb

4) Small

An FDP avulsion is caused by forceful extension of the distal interphalangeal (DIP) joint, occurring at the same time as a maximum contraction of the FDP tendon. Jersey finger is often seen in athletes, especially football or rugby players, who commonly get their fingers caught in an opposing playerâs jersey, thus the name. In most cases, this injury affects the ring finger.

■Correct Answer:Ring

1622. (3945) Q4-8196:

Which type of flexor digitorum profundus (FDP) avulsion is considered the most severe:

1) Type I

3) Type III

2) Type II

5) Type V

4) Type IV

Type I is the most threatening scenario because the FDP tendon retracts into the palm, and vincular and diffusional blood supply is lost. The sheath may be noncompliant after a few days and may not allow passage of the FDP tendon through the sheath in an attempt to repair the stump to its insertion. Additionally, proximal muscle contracture prevents tendon stump

advancement.

■Correct Answer:Type I

1623. (3946) Q4-8197:

When performing pollicization to correct a hypoplastic thumb, the surgeon should rotate the index finger:

1) 120º

3) 150º

2) 135º

5) 180º

4) 165º

After the index finger is rotated 150º, the index finger will be in the ideal location as it mimics the position of where the thumb would have naturally been. This position allows for the greatest amount of grip and pinch strength possible.

■Correct Answer:150º

1624. (3947) Q4-8198:

For which types of thumb hypoplasia is pollicization the best option:

1) Type I

3) Type IIIA

2) Type II

5) Type I, type II, and type IIIA

4) Type IIIB

Reconstruction is possible and is therefore the best option for thumb hypoplasia in patients with type I, type II, and type IIIA. These three types of hypoplasia can be corrected because the thumb still has most of the bones and muscles intact. C orrective surgery is necessary to correct weak muscles or a tight web space between the thumb and index finger. When a type IIIB exists, reconstruction is not possible and pollicization must be performed.

■Correct Answer:Type I, type II, and type IIIA

1625. (3948) Q4-8199:

What is the most critical step in pollicization to create a normal-looking thumb:

1) C reating skin incisions with skin flaps that will allow a natural first web space

3) Shortening of the index finger metacarpal

2) Shortening of tendons

5) All of the above

4) C reating a hyperextended joint when stabilizing the metacarpophalangeal joint to the carpus

It is necessary to create a hand with a natural first web space, shorter tendons that allow for natural movement, a shorter metacarpal that ensures the finger will not grow to an unnatural length, and a hyperextended joint to create the most natural- looking hand possible.

■Correct Answer:All of the above

1626. (3949) Q4-8200:

All of the following may be present in a child with type IIIA hypoplasia except:

1) Metacarpophalangeal (MP) joint laxity

3) Lack of extensor pollicis longus

2) Web space contracture

5) Thenar muscle atrophy

4) Unstable carpometacarpal (C MC ) joint

Type IIIA hypoplasia includes web space narrowing, thenar atrophy, MP joint laxity, and extrinsic tendon abnormalities. Type IIIA is distinguished from a type IIIB by the fact that a stable C MC joint exists. Because a stable C MC joint exists, a reconstruction is the treatment of choice. When the C MC joint is unstable, as in type IIIB hypoplasia, a pollicization is necessary to restore thumb stability.

■Correct Answer:Unstable carpometacarpal (C MC ) joint

1627. (3950) Q4-8201:

The main 3-4 viewing portal for wrist arthroscopy lies in between which two tendons:

1) Extensor pollicis longus (EPL) and extensor carpi radialis brevis (EC RB)

3) Abductor pollicis longus (APL) and extensor carpi radialis longus (EC RL)

2) Extensor digitorum communis (EDC ) and extensor digiti minimi (EDM)

5) Extensor pollicis brevis (EPB) and APL

4) EPL and EDC

The 3-4 portal is the main viewing portal and is located between the third and fourth compartment. This portal is bordered by the extensor digitorum communis (EDC ) to the index finger, and the extensor pollicis longus (EPL) can be palpated in the âsoft spotâ 1 cm distal to Listers tubercle. This portal is usually the first portal to be made during wrist arthroscopy.

■Correct Answer:EPL and

EDC

1628. (3951) Q4-8202:

Which of the following ligaments acts as a neurovascular conduit:

1) Long radiolunate

3) Radioscapholunate

2) Radioscaphocapitate

5) Ulnotriquetral

4) Short radiolunate

The radioscapholunate ligament, otherwise known as the ligament of Testut, lacks structural intergrity and acts as a neurovascular conduit. This ligament is visible on the volar side of the wrist from the 3-4 portal in between the long radiolunate and short radiolunate ligaments.

■Correct Answer:Radioscapholunate

1629. (3952) Q4-8203:

C omplications after wrist arthroscopy occur in what percentage of patients:

1) 5%

3) 15%

2) 10%

5) 25%

4) 20%

The complication rate after routine wrist arthroscopy is between 2% and 5%.

■Correct Answer:5%

1630. (3953) Q4-8204:

C omplications after wrist arthroscopy occur in what percentage of patients:

1) 5%

3) 15%

2) 10%

5) 25%

4) 20%

The complication rate after routine wrist arthroscopy is between 2% and 5%.

■Correct Answer:5%

1631. (3954) Q4-8205:

The fracture fragment in Bennettâs fracture is located in which of the following areas of the hand:

1) Radiopalmar trapezium

3) Ulnopalmar trapezium

2) Dorsal thumb metacarpal base

5) Radiopalmer lunate

4) Ulnopalmar thumb metacarpal base

As an axial load is placed on the thumb tip, it drives the thumb metacarpal (MC ) base in a dorsal-radial direction. As the thumb MC base moves dorsoradially, a fracture is created in the volar, ulnar quadrant of the thumb MC base. Gedda and Moberg describe this as a ligament fracture avulsion. The volar, ulnar quadrant piece usually remains stationary, perhaps migrating a small amount distal the thumb metacarpal base moves dorsoradially, creating a fracture in the volar, ulnar quadrant of the trapezium.

■Correct Answer:Ulnopalmar thumb metacarpal base

1632. (3955) Q4-8206:

Which of the following two main soft tissue forces are disrupted by Bennettâs fracture subluxation:

1) Volar beak (anterior oblique) ligament and extensor pollicis longus

3) Posterior oblique ligament and abductor pollicis brevis

2) Volar beak (anterior oblique) ligament and abductor pollicis longus

5) Dorsal radial ligament and abductor pollicis brevis

4) Dorsal radial ligament and flexor pollicis brevis

The volar, ulnar quadrant piece usually remains stationary due to the volar beak ligament. The thumb metacarpal base tends to sublux dorsoradially due to unopposed pull of the abductor pollicis longus and adductor pollicis. The intact volar beak ligament is usually the counterforce the to these two muscles in the static situation. The extensor pollis longus, flexor pollicis brevis, and abductor pollis longus do not have significant involvement in the Bennettâs fracture subluxation. Although the dorsal radial ligament is important for carpometacarpal stability, it is not the ligament attached to the fractures fragment.

■Correct Answer:Volar beak (anterior oblique) ligament and abductor pollicis longus

1633. (3956) Q4-8207:

The greatest amount of step-off that is well-tolerated in a Bennettâs fracture is:

1) 0 mm

3) 2 mm to 3 mm

2) 1 mm to 2 mm

5) 4 mm to 5 mm

4) 3 mm to 4 mm

Studies by Livesley, Kjaer-Petersen, and others have shown that patients with fractures with more than a 1-mm step-off after reduction were more likely to develop arthritis at the thumb carpometacarpal joint. Although some studies have not shown functional outcome correlating with the presence of arthritis, Oosterbos and De Boer found that all their patients with fair and poor overall results had nonanatomic reductions. Although a cadaveric study by C ullen has shown that a 2-mm step-off may be acceptable, this contrasts with the clinical evidence currently available.

■Correct Answer:1 mm to 2 mm

1634. (3957) Q4-8208:

When fracture step-off is greater than the accepted limits, which of the following complications is the most common:

1) Arthritis

3) Decreased range of motion

2) Pain

5) All of the above

4) Decreased pinch strength

Studies by Livesley, Kjaer-Petersen, and others have shown that patients with fractures with more than a 1-mm step-off after reduction were more likely to develop arthritis at the thumb carpometacarpal joint. Pain, decreased range of motion, and decreased pinch strength also correlated with these poor outcomes.

■Correct Answer:All of the above

1635. (3958) Q4-8209:

C linically, what is the upper limit of acceptable fracture angulation for a fifth metacarpal neck fracture:

1) 20°

3) 50°

2) 40°

5) 80°

4) 70°

Although this is controversial, conservatively treated patients with angulations less than 70° fared well in two prospective studies. Fourteen percent of patients will have a cosmetic deformity, but operatively treated patients exhibited extensor lag and increased rehabilitation times.

■Correct Answer:70°

1636. (3959) Q4-8210:

In cadaveric models, when does the biomechanics of fifth finger flexion consistently change in relationship to metacarpal neck fracture angulation:

1) 10°

3) 50°

2) 30°

5) 80°

4) 70°

Thirty degrees of angulation is the maximum deformity for acceptable fifth finger grip strength. Ali et al showed that fracture angulation of 30° results in a significant decrease in the distance between the origin and the insertion of the flexor digiti minimi (FDM). This shortening creates more âslackâ in the FDM muscle and more excursion is wasted as muscle shortening prior to the initiation of metacarpophalangeal (MP) flexion.

■Correct Answer:30°

1637. (3960) Q4-8211:

Up to how much angulation can be tolerated in the small finger metacarpal shaft fracture:

1) 0° to 10°

3) 21° to 30°

2) 11° to 20°

5) 41° to 50°

4) 31° to 40°

The small finger carpometacarpal joint is mobile, which allows the small finger metacarpal to tolerate deformity better than the fixed index and middle finger rays. Thus, 41° to 50° of angulation can be accommodated by the mobile carpometacarpal joint.

■Correct Answer:41° to 50°

1638. (3961) Q4-8212:

If a metacarpal shaft fracture shortens 4 mm, what will the theoretical amount of extensor lag be at the metacarpophalangeal joint:

1) 0°

3) 7°

2) 5°

5) 20°

4) 14°

For each 2 mm of shortening, a 7° extensor lag exists. Thus, with 4 mm of shortening, there will be a 14° extensor lag at the metacarpophalangeal joint.

■Correct Answer:14°

1639. (4069) Q4-8213:

In a short oblique metacarpal shaft fracture without comminution or bone loss, what is usual amount of maximal shortening that will occur:

1) 1 mm

3) 5 mm

2) 3 mm

5) 9 mm

4) 7 mm

In a cadaveric study, shortening beyond 5 mm was prevented by the tethering effect of the transverse metacarpal ligaments and adjacent metacarpals.

■Correct Answer:5 mm

1640. (3962) Q4-8214:

Which of the following statements is true regarding metacarpophalangeal joint anatomy:

1) The collateral ligaments are lax in flexion.

3) Joint stability is maximal in flexion.

2) The joint volume is highest in flexion.

5) The collateral ligaments originate volar to the axis of flexion.

4) The metacarpal head is spherical.

The collateral ligaments are lax in extension and tight in flexion. The joint volume is highest in extension. The metacarpal head is cam-shaped. The collateral ligaments originate dorsal to the axis of flexion. Due to the tightening of the collateral ligaments over the cam-shaped metacarpal head in flexion, joint stability is maximized.

■Correct Answer:Joint stability is maximal in flexion.

1641. (3963) Q4-8215:

Which of the following fracture patterns and mechanisms is incorrectly paired:

1) Transverse fracture-direct blow

3) C omminuted fractures with a butterfly fragment-axial compression and bending

2) Transverse fracture-axial load on an extended metacarpophalangeal joint

5) Oblique-torsion and axial load

4) Spiral fracture-torsion

Biomechanically and clinically, fracture patterns are often associated with certain types of force. Transverse fractures occur with a direct blow, comminuted fractures occur with axial compression and bending, spiral fractures occur in torsion, and oblique fractures occur with torsion and axial load.

■Correct Answer:Transverse fracture-axial load on an extended metacarpophalangeal joint

1642. (3964) Q4-8216:

Giant cell tumor of tendon sheath commonly occurs in which of the following age groups:

1) Infants (age 0-1 year)

3) Age 10-20 years

2) Age 1-10 years

5) Age 60-70 years

4) Age 30-40 years

Giant cell tumor of tendon sheath is most commonly found in patients in the fourth through sixth decades; therefore, age 30-40 years is the most appropriate answer choice.

■Correct Answer:Age 30-40 years

1643. (3965) Q4-8217:

Which of the following clinical features is common in giant cell tumor of tendon sheath:

1) Transillumination

3) Fluctuates in size

2) Erythematous

5) Painless

4) Presents with rapid change in size

Giant cell tumor of tendon sheath is painless. Giant cell tumor of tendon sheath does not transilluminate, as ganglion cyst does. No overlying skin color changes occur. Giant cell tumor of tendon sheath only increases in size and does not fluctuate like a ganglion cyst; it does not present with a rapid increase in size.

■Correct Answer:Painless

1644. (3966) Q4-8218:

After plain radiographs of giant cell tumor of tendon sheath are obtained, the following imaging study should be obtained:

1) C omputed tomography scan

3) Magnetic resonance image

2) Ultrasound

5) Bone scan

4) Angiogram

Magnetic resonance imaging provides anatomic detail of the soft tissue mass, helps generate a differential diagnosis, and determines if the mass is unifocal or multifocal and where it originates. Giant cell tumor of tendon sheath is a soft-tissue tumor. C omputed tomography is best for bone-based tumors. Ultrasound helps localize lesions but does not provide anatomic detail to help determine the type of mass. Although angiograms are useful for vascular tumors such as renal cell carcinoma or arteriovenous malformations, they are not necessary in the evaluation of a soft tissue mass in the hand with features suggestive of giant cell tumor of tendon sheath. A bone scan is useful when malignant bone tumors are suspected rather than benign soft tissue masses.

■Correct Answer:Magnetic resonance image

1645. (3967) Q4-8219:

Which of the following cell types is not typically found in giant cell tumors of tendon sheath:

1) Multinucleated giant cells

3) Monocytes

2) Histiocytes

5) Fibroblasts

4) Polymorphonuclear lymphocytes

Multinucleated giant cells, histiocytes, monocytes, and fibroblasts are commonly found in pathologic giant cell tumor of tendon sheath specimens. Polymorphonuclear lymphocytes are typically associated with bacterial infections.

■Correct Answer:Polymorphonuclear lymphocytes

1646. (3968) Q4-8220:

A 25-year-old, right-hand-dominant male truck driver presents to the emergency department (Slide 1, Slide 2). The tip of his left ring finger was amputated in a bicycle accident 2 weeks prior. The amputated piece was âsewn back onâ in the emergency department immediately after the accident, but âturned blackâ over the next week. There is no evidence of infection. He states that the appearance of his finger is embarrassing, and he would like it taken care of as soon as possible. Which of the following procedures is the most appropriate:

1) Local debridement, allow to heal by secondary intention

3) Kutler V-Y advancement flap closure

2) Atasoy-Kleinert V-Y advancement flap closure

5) Split-thickness hypothenar skin graft

4) Moberg flap closure

The Atasoy-Kleinert V-Y advancement flap is the best option for transversely oriented fingertip amputations/defects and also for defects with more dorsal than volar tissue loss. The apex of the V is positioned at, or just distal, to the distal interphalangeal joint crease on the volar side of the digit. After incising the V marking, the flap is advanced distally to cover the defect, and the incisions are closed in a Y pattern.

Local, or chemical, debridement and allowing the resulting defect to heal by secondary intention are a viable option, but the patient stated that he would prefer an aggressive treatment protocol because the appearance of his fingertip is so embarrassing.

The Kutler (lateral) V-Y advancement flap is typically used to cover tip defects that demonstrate more volar than dorsal tissue loss. The procedure involves creating V-Y advancement flaps laterally on either side of the affected digit and advancing them toward each other in the midline thereby covering the defect.

The Moberg flap is typically used for reconstruction of thumb amputations. This procedure involves the creation of volar tissue flap that includes the neurovascular bundles on either side of the digit. Its use is cautioned in very distal amputations because excess stretch on the vascular pedicles may lead to necrosis at the tip of the flap. Its use is also cautioned in the fingers because of the difference in orientation of the blood supply compared to the thumb.

A full-thickness, rather than a split-thickness, skin graft is a viable option to manage this patient. Skin grafts for hand reconstruction should be harvested with the âlike replaces likeâ principle in mind, especially when reconstructing the volar skin. Volar hand skin is much thicker and of unique quality when compared with the rest of the body, and therefore, the most appropriate place to harvest a skin graft is the volar surface of the hand.

 

■Correct Answer:Atasoy-Kleinert V-Y advancement flap closure

1647. (3969) Q4-8221:

A 52-year-old, right-hand-dominant watchmaker arrives at the emergency department 30 minutes after the volar soft tissue of his right thumb and index finger was avulsed while using a bandsaw. Physical examination shows 2 cm 3 2 cm wounds involving the distal phalanx of each affected digit. No exposed tendon or bone is present, and no involvement of the joints is noted. The patient requests a treatment option that will retain the most sensation so he can effectively continue in his occupation. Which of the following options is the most appropriate management of this patientâs wounds:

1) C overage with cross-finger flaps

3) Split-thickness skin grafting

2) Healing by secondary intention

5) Radial free forearm flap

4) Full-thickness skin grafting

Local flaps such as cross finger flaps are good options but require at least two surgeries (inset then division) and can often result in stiffness secondary to the requisite period of immobilization. In addition, local flaps have lesser return of sensibility than the other techniques listed.

Return of tactile sensibility is excellent after healing by secondary intention, but dressing changes for wounds that measure 2 cm 3

2 cm would take months to completely heal.

Skin grafting is the next available option with acceptable sensory return. It can be performed during local anesthesia, requires only one operation, and allows for early motion thereby avoiding stiffness. Studies have shown that full-thickness skin grafts recover sensation better than split-thickness skin grafts.

A radial forearm flap will be excessively bulky, has unacceptable donor site morbidity in this situation, and results in inadequate sensory recovery.

 

■Correct Answer:Full-thickness skin grafting

1648. (3970) Q4-8222:

Which of the following is not considered a part of the triangular fibrocartilage complex:

1) Ulnolunate ligament

3) Dorsal radioulnar ligament

2) Palmar radioulnar ligament

5) Ulnotriquetral ligament

4) Radiolunate ligament

The triangular fibrocartilage complex is made up of the dorsal and palmar radioulnar ligaments, the meniscal homologue, the articular disk, the ulnolunate, and the ulnotriquetral ligaments. The radiolunate ligament is not part of the complex.

■Correct Answer:Radiolunate ligament

1649. (3971) Q4-8223:

Which of the following arterial branches does not supply the peripheral 25% of the triangular fibrocartilage complex:

1) Dorsal branch of the anterior interosseous artery

3) Dorsal branch of the radial artery

2) Palmar branch of the anterior interosseous artery

5) Palmar branch of the ulnar artery

4) Dorsal branch of the ulnar artery

The triangular fibrocartilage complex is supplied by both branches of the anterior interosseous artery and the ulnar artery; it is not supplied by the dorsal branch of the radial artery.

■Correct Answer:Dorsal branch of the radial artery

1650. (3972) Q4-8224:

Which of the following statements is true:

1) In a wrist with neutral ulnar variance, 20% of the axial load is transmitted across the ulna.

3) In a wrist with 2.5 mm ulnar negative variance, 60% of the axial load is transmitted across the ulna.

2) In a wrist with 2.5 mm ulnar negative variance, 20% of the axial load is transmitted across the ulna.

5) In a wrist with 2.5 ulnar positive variance, 20% of the axial load is transmitted across the ulna.

4) In a wrist with 2.5 mm ulnar positive variance, 600% of the axial load is transmitted across the ulna.

C adaveric studies have been performed to determine the amount of load across the wrist with various relationships between the radius and ulna lengths. In wrists with neutral ulnar variance (in which the radius and ulna are equal in length), 20% of the load is transmitted across the ulna and 80% is transmitted across the radius. In wrists with negative ulnar variance (in which the ulnar is shorter than the radius), more load is transmitted across the radius and less is transmitted across the ulna. The opposite is true with positive ulnar variance (the ulna is longer than the radius).

■Correct Answer:In a wrist with neutral ulnar variance, 20% of the axial load is transmitted across the ulna.