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7. Hand and Wrist MCQs

Practice Set 240 of 266

This practice set contains high-yield board review questions covering key concepts in 7. Hand and Wrist. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 4781

Topic: 7. Hand and Wrist

During a traumatic laceration repair of the volar thumb, careful preservation or reconstruction of the flexor pulley system is essential. Biomechanically, which pulley in the thumb is the most critical to prevent bowstringing of the flexor pollicis longus (FPL) tendon?

. A1 pulley
. A2 pulley
. Oblique pulley
. Annular pulley
. Cruciate pulley

Correct Answer & Explanation

. Oblique pulley

Explanation

The oblique pulley is the most critical biomechanical pulley in the thumb to prevent bowstringing of the FPL tendon. It originates proximally on the ulnar aspect of the proximal phalanx and inserts distally on the radial aspect.

Question 4782

Topic: Wrist & Carpus

A 50-year-old man presents with advanced Scapholunate Advanced Collapse (SLAC) wrist. When considering a Proximal Row Carpectomy (PRC) as a surgical option, which of the following radiographic findings serves as an absolute contraindication to this procedure?

. A scapholunate angle greater than 70 degrees
. Advanced radioscaphoid osteoarthritis
. Advanced capitolunate osteoarthritis
. Ulnar positive variance of 2 mm
. Lunate type I morphology

Correct Answer & Explanation

. Advanced capitolunate osteoarthritis

Explanation

Proximal Row Carpectomy (PRC) relies on a preserved articulation between the head of the capitate and the lunate fossa of the distal radius. Therefore, significant osteoarthritis of the capitolunate joint or the capitate head is a contraindication.

Question 4783

Topic: 7. Hand and Wrist

A 28-year-old industrial worker accidentally injects his non-dominant index finger with a high-pressure paint gun. There is a pinpoint puncture wound over the volar proximal phalanx with minimal swelling. Which factor is the most important prognostic indicator regarding the risk of subsequent digital amputation?

. Age of the patient
. Type of injected material
. Digit involved
. Time elapsed until initiation of intravenous antibiotics
. Size of the entrance wound

Correct Answer & Explanation

. Type of injected material

Explanation

The type of material injected is the most critical prognostic factor in high-pressure injection injuries. Organic solvents, paint, and oil-based compounds cause severe chemical necrosis with a very high rate of amputation compared to water or air.

Question 4784

Topic: 7. Hand and Wrist

A 24-year-old man presents with a symptomatic nonunion of a proximal pole scaphoid fracture. Which surgical approach is generally most appropriate, and what is its primary anatomic advantage?

. Volar approach; it preserves the major dorsal retrograde blood supply to the scaphoid.
. Dorsal approach; it allows direct access to the proximal pole without dividing the volar radioscaphocapitate ligament.
. Volar approach; it allows optimal visualization of the scaphotrapezial joint.
. Dorsal approach; it prevents injury to the palmar cutaneous branch of the median nerve.
. Lateral approach; it minimizes disruption to the deep branch of the radial artery.

Correct Answer & Explanation

. Dorsal approach; it allows direct access to the proximal pole without dividing the volar radioscaphocapitate ligament.

Explanation

A dorsal approach provides excellent, direct visualization of the intra-articular proximal pole of the scaphoid. Crucially, it avoids cutting the stout volar radioscaphocapitate ligament, which is a key secondary stabilizer.

Question 4785

Topic: 7. Hand and Wrist

A 45-year-old construction worker presents with chronic wrist pain and weakness. Radiographs demonstrate a widened scapholunate interval, proximal migration of the capitate, and advanced osteoarthritic changes at the radioscaphoid and capitolunate joints. Which of the following articulations is characteristically spared in this disease process?

. Radioscaphoid joint
. Scaphocapitate joint
. Capitolunate joint
. Radiolunate joint
. Trapeziometacarpal joint

Correct Answer & Explanation

. Radiolunate joint

Explanation

The clinical picture describes Scapholunate Advanced Collapse (SLAC). In SLAC wrist, the radiolunate joint is characteristically spared because of the congruent spherical articulation and the robust short radiolunate ligament, which maintains the lunate's relationship with the radius even as the scaphoid rotates and the capitate migrates proximally.

Question 4786

Topic: Nerve & Tendon

A 55-year-old patient with long-standing rheumatoid arthritis presents with a fixed flexion deformity of the proximal interphalangeal (PIP) joint and hyperextension of the distal interphalangeal (DIP) joint of the right index finger. Which of the following represents the primary pathomechanics of this specific deformity?

. Attenuation of the central slip with volar subluxation of the lateral bands
. Rupture of the terminal extensor tendon with dorsal subluxation of the lateral bands
. Volar plate laxity leading to intrinsic muscle contracture
. Sagittal band rupture allowing the extensor tendon to subluxate into the web space
. Isolated rupture of the flexor digitorum superficialis (FDS) tendon

Correct Answer & Explanation

. Attenuation of the central slip with volar subluxation of the lateral bands

Explanation

The patient has a Boutonniere deformity. In rheumatoid arthritis, synovitis at the PIP joint leads to stretching and attenuation of the central slip. This allows the lateral bands to subluxate volarly below the axis of rotation of the PIP joint, where they act as flexors of the PIP joint while continuing to exert a strong extension force on the DIP joint.

Question 4787

Topic: 7. Hand and Wrist

An avid cyclist presents with profound weakness of the interosseous muscles and adductor pollicis in his right hand. He exhibits a positive Froment's sign. Sensory examination reveals normal two-point discrimination over the volar aspect of the small finger and the dorsal ulnar aspect of the hand. Where is the most likely anatomic site of nerve compression?

. Cubital tunnel
. Arcade of Struthers
. Zone 1 of Guyon's canal
. Zone 2 of Guyon's canal
. Zone 3 of Guyon's canal

Correct Answer & Explanation

. Zone 2 of Guyon's canal

Explanation

The patient has isolated motor deficits of the ulnar nerve without sensory involvement, localizing the lesion to Zone 2 of Guyon's canal (which contains only the deep motor branch). Zone 1 contains the mixed nerve, and Zone 3 contains only the superficial sensory branch. Normal dorsal ulnar sensation rules out lesions proximal to the wrist (e.g., cubital tunnel), as the dorsal ulnar cutaneous branch arises 5-8 cm proximal to the wrist.

Question 4788

Topic: Nerve & Tendon

A 22-year-old rugby player felt a sudden 'pop' in his ring finger while trying to grab an opponent's jersey. Examination shows an inability to actively flex the DIP joint. Radiographs show no fractures, and ultrasound indicates the FDP tendon is retracted into the palm (Leddy-Packer Type I). What is the critical timeframe within which primary repair must be performed?

. Within 7 to 10 days
. Within 3 weeks
. Within 6 weeks
. Within 3 months
. Delayed reconstruction with a tendon graft is primarily indicated immediately

Correct Answer & Explanation

. Within 7 to 10 days

Explanation

A Leddy-Packer Type I 'Jersey finger' involves avulsion of the FDP tendon with retraction all the way into the palm. This disrupts all segmental blood supply (vincula), placing the tendon at high risk for myostatic contracture and avascular necrosis. Primary repair must be performed early, ideally within 7 to 10 days, to allow for successful anatomic reinsertion.

Question 4789

Topic: 7. Hand and Wrist
A 28-year-old male falls on an outstretched dorsiflexed hand. Lateral wrist radiographs demonstrate the 'spilled teacup' sign, indicating a lunate dislocation. According to Mayfield's stages of perilunate instability, what structural failure immediately precedes the volar dislocation of the lunate (Stage IV)?
. Radioscaphoid ligament rupture
. Scapholunate interosseous ligament tear
. Capitolunate articulation disruption
. Lunotriquetral interosseous ligament disruption
. Dorsal radiocarpal ligament avulsion

Correct Answer & Explanation

. Lunotriquetral interosseous ligament disruption

Explanation

Mayfield described a progressive, four-stage sequence of perilunate instability. Stage I: Scapholunate disruption. Stage II: Capitolunate disruption. Stage III: Lunotriquetral disruption. Stage IV: Lunate dislocation (usually volar into the carpal tunnel). Thus, lunotriquetral disruption (Stage III) immediately precedes the enucleation of the lunate.

Question 4790

Topic: 7. Hand and Wrist

A patient presents with difficulty writing and a weak pinch grip. When asked to form an 'OK' sign, the index finger and thumb pulp meet flatly rather than forming a circle. Sensation over the entire hand is completely intact. Which of the following conditions is the most likely diagnosis?

. Pronator syndrome
. Anterior interosseous nerve (AIN) syndrome
. Carpal tunnel syndrome
. Radial tunnel syndrome
. Cubital tunnel syndrome

Correct Answer & Explanation

. Anterior interosseous nerve (AIN) syndrome

Explanation

Anterior Interosseous Nerve (AIN) syndrome is a pure motor neuropathy affecting the flexor pollicis longus (FPL), flexor digitorum profundus (FDP) to the index/middle fingers, and the pronator quadratus. The classic clinical sign is the inability to form an 'OK' sign, resulting in a flat pinch. The lack of sensory deficits distinguishes it from Pronator syndrome and Carpal tunnel syndrome.

Question 4791

Topic: 7. Hand and Wrist
A 40-year-old manual laborer with advanced Kienböck's disease presents with chronic central wrist pain. Radiographs reveal lunate collapse, fixed scaphoid rotary subluxation, and significant carpal height loss, but the radiocarpal and midcarpal articular surfaces remain preserved (Lichtman Stage IIIb). Which of the following surgical options is most appropriate?
. Radial shortening osteotomy
. Proximal row carpectomy (PRC) or scaphocapitate (SC) fusion
. Core decompression of the distal radius
. Vascularized bone graft from the dorsal distal radius
. Total wrist arthrodesis

Correct Answer & Explanation

. Proximal row carpectomy (PRC) or scaphocapitate (SC) fusion

Explanation

In Lichtman Stage IIIb Kienböck's disease, there is lunate collapse combined with fixed carpal instability (scaphoid rotary subluxation) and carpal height loss. Joint leveling procedures (radial shortening) or revascularization are no longer effective at this stage. Salvage procedures such as Proximal Row Carpectomy (PRC) or limited intercarpal fusions (e.g., STT or SC fusion) are the standard treatments before extensive arthritis necessitates a total wrist fusion.

Question 4792

Topic: 7. Hand and Wrist

A 25-year-old basketball player presents with a bony mallet finger involving the middle finger. Radiographs show a dorsal articular avulsion fragment comprising 45% of the distal phalanx articular surface, accompanied by volar subluxation of the distal phalanx. What is the most appropriate management?

. Continuous Stack splinting for 8 weeks
. Extension block pinning (Ishiguro technique)
. Primary repair of the terminal tendon using a suture anchor
. Primary DIP joint arthrodesis
. Figure-of-eight buddy taping and immediate early active motion

Correct Answer & Explanation

. Extension block pinning (Ishiguro technique)

Explanation

While most soft tissue and non-subluxated bony mallet fingers are treated with extension splinting, surgical intervention is indicated for bony mallet fingers with >30-40% articular involvement AND volar subluxation of the distal phalanx. Extension block pinning (Ishiguro technique) effectively reduces the fracture and restores joint congruity without the complication risks of open reduction.

Question 4793

Topic: Hand Trauma & Infection

A 30-year-old diabetic patient presents to the emergency department with a swollen, painful index finger three days after sustaining a minor puncture wound. Which of Kanavel's four cardinal signs is generally considered the earliest and most sensitive indicator of pyogenic flexor tenosynovitis?

. Fusiform swelling of the digit
. Flexed resting posture of the digit
. Pain elicited by passive extension of the digit
. Tenderness to palpation along the flexor tendon sheath
. Erythema extending proximal to the metacarpophalangeal joint

Correct Answer & Explanation

. Pain elicited by passive extension of the digit

Explanation

Kanavel's signs for pyogenic flexor tenosynovitis are: 1) flexed resting posture, 2) fusiform (sausage-like) swelling, 3) tenderness strictly along the tendon sheath, and 4) pain with passive extension. Pain on passive extension is widely regarded as the earliest and most sensitive clinical sign, as it stretches the inflamed visceral and parietal synovium.

Question 4794

Topic: 7. Hand and Wrist

A 32-year-old new mother complains of severe radial-sided wrist pain exacerbated by lifting her infant. A Finkelstein's test is markedly positive. This pathology involves stenosing tenosynovitis of the first dorsal compartment of the wrist. Which tendons are contained within this compartment?

. Abductor pollicis longus (APL) and extensor pollicis brevis (EPB)
. Extensor pollicis longus (EPL) and extensor pollicis brevis (EPB)
. Extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB)
. Extensor digitorum communis (EDC) and extensor indicis proprius (EIP)
. Abductor pollicis longus (APL) and flexor carpi radialis (FCR)

Correct Answer & Explanation

. Abductor pollicis longus (APL) and extensor pollicis brevis (EPB)

Explanation

De Quervain's tenosynovitis involves the first dorsal compartment of the wrist. This compartment contains the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons. Anatomical variations, such as multiple APL slips or a distinct sub-compartment for the EPB, are common and can contribute to recalcitrant symptoms.

Question 4795

Topic: Wrist & Carpus

Following open reduction and internal fixation of a distal radius fracture with a volar locking plate, the patient develops a delayed rupture of the flexor pollicis longus (FPL) tendon. The surgeon placed the plate distal to a critical anatomical landmark, leading to tendon attrition. What is this landmark?

. Lister's tubercle
. The watershed line
. The sigmoid notch
. The volar radioulnar ligament
. The pronator quadratus fossa

Correct Answer & Explanation

. The watershed line

Explanation

The 'watershed line' is a distinct anatomical ridge on the volar surface of the distal radius. It marks the most volar projection of the distal radius. Volar plates placed distal to the watershed line are prominent relative to the flexor tendons, creating a high risk for attritional rupture, particularly of the flexor pollicis longus (FPL) tendon.

Question 4796

Topic: 7. Hand and Wrist

A pediatric orthopedic surgeon is evaluating a 1-year-old child with congenital syndactyly of the hand. Inherited primarily in an autosomal dominant fashion with incomplete penetrance, what is the most common anatomical location for this anomaly?

. First web space (thumb-index)
. Second web space (index-middle)
. Third web space (middle-ring)
. Fourth web space (ring-small)
. Complex syndactyly involving the entire ulnar border

Correct Answer & Explanation

. Third web space (middle-ring)

Explanation

Congenital syndactyly most commonly affects the third web space, between the middle and ring fingers. It occurs due to a failure of apoptosis during embryogenesis. The second most common site is the fourth web space, followed by the second web space.

Question 4797

Topic: 7. Hand and Wrist

A trauma patient sustains an ulnar nerve laceration. The physical examination reveals a severe claw hand deformity (hyperextension of the MCP joints and flexion of the IP joints of the ring and small fingers). A lesion at the wrist paradoxically produces a more severe claw deformity than a lesion at the elbow. What is the physiological basis for this 'ulnar paradox'?

. High lesions denervate the lumbricals, eliminating MCP hyperextension
. High lesions denervate the FDP to the ring and small fingers, reducing unantagonized DIP flexion
. Low lesions cause reactive hypertonia of the extensor digitorum communis
. Low lesions spare the palmaris brevis, which pulls the hypothenar eminence into flexion
. High lesions preserve the function of the superficialis tendons, balancing the digit

Correct Answer & Explanation

. High lesions denervate the FDP to the ring and small fingers, reducing unantagonized DIP flexion

Explanation

The 'ulnar paradox' occurs because a high ulnar nerve injury (above the elbow) paralyses not only the intrinsic hand muscles but also the ulnar half of the Flexor Digitorum Profundus (FDP). Without active FDP contraction, there is less forceful flexion at the DIP joints of the ring and small fingers, resulting in a milder claw posture. In a low lesion, the FDP remains innervated and its unantagonized pull exacerbates the clawing.

Question 4798

Topic: Wrist & Carpus

A 62-year-old female with long-standing rheumatoid arthritis presents with an inability to actively extend her ring and small fingers at the metacarpophalangeal joints. She can still extend her index and middle fingers. The tenodesis effect is absent in the affected digits. What is the most appropriate management?

. Sagittal band reconstruction
. Extensor indicis proprius (EIP) transfer to the affected digits
. Side-to-side transfer of the affected extensor tendons to the intact extensor digitorum communis of the middle finger
. Distal radioulnar joint (DRUJ) arthroplasty
. Extensor carpi radialis longus (ECRL) transfer

Correct Answer & Explanation

. Side-to-side transfer of the affected extensor tendons to the intact extensor digitorum communis of the middle finger

Explanation

This patient has Vaughan-Jackson syndrome, characterized by sequential rupture of the extensor tendons from the ulnar to the radial side due to attrition over a prominent distal ulna (caput ulnae). Treatment involves removing the prominent ulnar head (e.g., Darrach or Suave-Kapandji) and transferring the ruptured EDQ and EDC of the ring/small fingers side-to-side to the intact EDC of the middle finger.

Question 4799

Topic: 7. Hand and Wrist
According to the Watson staging system for Scapholunate Advanced Collapse (SLAC) wrist, which articulation is characteristically spared from degenerative changes even in advanced stages?
. Radioscaphoid joint
. Lunocapitate joint
. Radiolunate joint
. Scaphotrapezial joint
. Capitolunate joint

Correct Answer & Explanation

. Radiolunate joint

Explanation

In the SLAC wrist, the radiolunate articulation is classically spared because the lunate maintains a concentric, congruent relationship with the spherical lunate fossa of the distal radius, unlike the scaphoid which becomes flexed and incongruent. Stage I involves the radial styloid-scaphoid joint; Stage II involves the entire radioscaphoid joint; Stage III involves the capitolunate joint.

Question 4800

Topic: 7. Hand and Wrist

A 40-year-old carpenter presents with the inability to make an 'OK' sign with his thumb and index finger. Sensation in his hand is entirely normal. Which of the following muscles is most likely to be affected?

. Abductor pollicis brevis
. Flexor digitorum superficialis to the index finger
. Flexor pollicis longus
. Adductor pollicis
. Extensor pollicis longus

Correct Answer & Explanation

. Flexor pollicis longus

Explanation

Anterior Interosseous Nerve (AION) palsy presents with pure motor deficits affecting the Flexor Pollicis Longus (FPL), Flexor Digitorum Profundus (FDP) to the index (and sometimes middle) finger, and the pronator quadratus. This results in the inability to flex the IP joint of the thumb and the DIP joint of the index finger (a positive 'OK' sign).

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