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7. Hand and Wrist MCQs

Practice Set 118 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 2341

Topic: 7. Hand and Wrist
A 32-year-old male carpenter presents with chronic dorsal wrist pain and weak grip strength. Radiographs reveal sclerosis, fragmentation, and collapse of the lunate. The radioscaphoid angle is measured at 65 degrees, indicating fixed scaphoid rotation, and carpal height is decreased. Ulnar variance is neutral. According to the Lichtman classification, this represents Stage IIIB Kienböck's disease. What is the most appropriate surgical treatment?
. Radial shortening osteotomy
. Core decompression of the distal radius
. Proximal row carpectomy (PRC)
. Vascularized bone grafting from the distal radius
. Lunate excision with no interposition

Correct Answer & Explanation

. Proximal row carpectomy (PRC)

Explanation

The patient has Lichtman Stage IIIB Kienböck's disease, characterized by lunate fragmentation/collapse, carpal collapse, and fixed scaphoid rotation (scaphoid angle > 60 degrees). At this advanced stage with altered carpal kinematics, joint-leveling procedures (like radial shortening osteotomy, which are excellent for Stage II/IIIA with ulnar minus variance) are no longer effective. Salvage procedures such as Proximal Row Carpectomy (PRC) or limited intercarpal fusions (e.g., STT or SC fusion) are indicated to address the collapse and provide a stable, pain-free wrist.

Question 2342

Topic: 7. Hand and Wrist

A 50-year-old female who underwent open reduction and internal fixation of a distal radius fracture with a volar locking plate 4 months ago presents with the sudden inability to bend the tip of her thumb. She experienced a snapping sensation earlier that day without significant trauma. The most likely cause of this complication is:

. Attritional rupture of the flexor pollicis longus (FPL) tendon against the prominent plate
. Delayed iatrogenic injury to the anterior interosseous nerve (AIN) from deep scar tissue
. Attritional rupture of the extensor pollicis longus (EPL) tendon at Lister's tubercle
. Ischemic contracture of the flexor digitorum profundus (FDP) muscles
. Adhesive tenosynovitis within the carpal tunnel

Correct Answer & Explanation

. Attritional rupture of the flexor pollicis longus (FPL) tendon against the prominent plate

Explanation

Attritional rupture of the flexor pollicis longus (FPL) tendon is a well-recognized complication of volar plate fixation for distal radius fractures. It usually occurs when the plate is placed distally beyond the watershed line of the distal radius, creating friction against the FPL tendon during thumb motion. EPL rupture is common in non-operatively managed distal radius fractures, but FPL rupture is the classic complication of prominent volar hardware.

Question 2343

Topic: 7. Hand and Wrist

The vascular supply to the proximal pole of the scaphoid is predominantly derived from retrograde flow via which of the following vessels?

. Superficial palmar branch of the radial artery
. Volar carpal branch of the radial artery
. Dorsal carpal branch of the radial artery
. Anterior interosseous artery
. Ulnar artery via the deep palmar arch

Correct Answer & Explanation

. Dorsal carpal branch of the radial artery

Explanation

The major blood supply to the scaphoid (70-80%, including the entire proximal pole) comes from branches of the radial artery, specifically the dorsal carpal branch. These vessels enter the dorsal ridge of the scaphoid and flow in a retrograde direction (distal to proximal), which is why proximal pole fractures have a high risk of avascular necrosis and nonunion.

Question 2344

Topic: 7. Hand and Wrist

Which of the following locations of a scaphoid fracture is associated with the highest rate of avascular necrosis and non-union, and what is the anatomic basis for this?

. Distal pole; due to direct blood supply from the superficial palmar arch
. Waist; due to the insertion of the radioscaphocapitate ligament
. Proximal pole; due to retrograde blood supply from the dorsal carpal branch of the radial artery
. Tuberosity; due to attachment of the transverse carpal ligament
. Waist; due to a tenuous blood supply from the anterior interosseous artery

Correct Answer & Explanation

. Proximal pole; due to retrograde blood supply from the dorsal carpal branch of the radial artery

Explanation

The scaphoid receives its primary blood supply from the dorsal carpal branch of the radial artery, which enters the bone distally and flows in a retrograde fashion to the proximal pole. Therefore, fractures of the proximal pole disrupt this delicate retrograde flow, leading to the highest rates of avascular necrosis and non-union among all scaphoid fractures.

Question 2345

Topic: 7. Hand and Wrist
In the flexor tendon anatomy of the hand, the flexor digitorum superficialis (FDS) tendon splits to allow the flexor digitorum profundus (FDP) tendon to pass through. This anatomic structural decussation is known as Camper's chiasm. In which flexor tendon zone is Camper's chiasm located?
. Zone I
. Zone II
. Zone III
. Zone IV
. Zone V

Correct Answer & Explanation

. Zone II

Explanation

Camper's chiasm is the structural split in the flexor digitorum superficialis (FDS) tendon that allows the deeper flexor digitorum profundus (FDP) tendon to emerge superficially to insert on the distal phalanx. This structure is located within flexor tendon Zone II (No Man's Land), which extends from the A1 pulley to the insertion of the FDS.

Question 2346

Topic: 7. Hand and Wrist
A 35-year-old manual laborer presents with progressive wrist pain. Radiographs reveal a scaphoid nonunion with radioscaphoid arthritis and capitolunate arthritis. The radiolunate joint is spared. This corresponds to Scaphoid Nonunion Advanced Collapse (SNAC) Stage III. Which of the following is the most appropriate surgical treatment?
. Proximal row carpectomy
. Scaphoid excision and four-corner fusion
. Radial styloidectomy
. Total wrist arthrodesis
. Vascularized bone grafting of the scaphoid

Correct Answer & Explanation

. Scaphoid excision and four-corner fusion

Explanation

In SNAC Stage III, there is radioscaphoid and capitolunate arthritis, but the radiolunate joint is spared. Proximal row carpectomy (PRC) is contraindicated because the capitate head (which articulates with the lunate fossa in PRC) is arthritic. Therefore, scaphoid excision and four-corner fusion (capitate-hamate-lunate-triquetrum) is the procedure of choice, as it preserves the healthy radiolunate joint.

Question 2347

Topic: Nerve & Tendon

A 40-year-old male undergoes electromyography (EMG) for suspected cubital tunnel syndrome. The nerve conduction study demonstrates a drop in the amplitude of the compound muscle action potential (CMAP) when stimulating the ulnar nerve at the elbow while recording from the abductor digiti minimi (ADM). However, the CMAP recorded from the first dorsal interosseous (FDI) is normal. This discrepancy is most likely explained by which anatomic variant?

. Riche-Cannieu anastomosis
. Marinacci anastomosis
. Martin-Gruber anastomosis
. Berrettini anastomosis
. Struthers ligament compression

Correct Answer & Explanation

. Martin-Gruber anastomosis

Explanation

A Martin-Gruber anastomosis involves crossover fibers from the median nerve to the ulnar nerve in the forearm. These fibers often supply the FDI. Because the crossover occurs distal to the elbow, a compressive lesion at the elbow will not affect the median-to-ulnar fibers innervating the FDI, leading to sparing of the FDI CMAP, while the ADM (supplied strictly by the ulnar nerve) will show a deficit.

Question 2348

Topic: 7. Hand and Wrist

A 28-year-old carpenter sustains a volar laceration to his index finger over the proximal phalanx, transecting both the FDS and FDP tendons (Zone II). He undergoes a primary 4-strand core suture repair with epitendinous running suture. Which of the following rehabilitation protocols has been shown to maximize tendon excursion while minimizing the risk of rupture and adhesions in the early postoperative period?

. Strict immobilization in a cast for 6 weeks
. Early active mobilization using a place-and-hold technique with a dorsal blocking splint
. Immediate free active unresisted motion without splinting
. Dynamic extension splinting with passive flexion exercises
. Continuous passive motion machine use for 24 hours a day

Correct Answer & Explanation

. Early active mobilization using a place-and-hold technique with a dorsal blocking splint

Explanation

Modern multi-strand core repairs provide sufficient tensile strength to allow for early active motion protocols. The 'place-and-hold' technique, utilizing a dorsal blocking splint, allows for differential glide of the FDS and FDP tendons. This significantly reduces adhesion formation while keeping the force across the repair below the rupture threshold.

Question 2349

Topic: 7. Hand and Wrist
A 45-year-old manual laborer presents with chronic wrist pain. Radiographs reveal a scaphoid nonunion with arthritic changes present in the radioscaphoid and capitolunate joints. The radiolunate joint is completely spared. Which of the following is the most appropriate motion-preserving surgical intervention?
. Radial styloidectomy
. Proximal row carpectomy (PRC)
. Scaphoid excision and four-corner arthrodesis
. Total wrist arthroplasty
. Scaphoid open reduction internal fixation with vascularized bone grafting

Correct Answer & Explanation

. Scaphoid excision and four-corner arthrodesis

Explanation

This patient has Scaphoid Nonunion Advanced Collapse (SNAC) Stage III, characterized by arthritis in the radioscaphoid and capitolunate joints with a preserved radiolunate joint. Because the capitate head is arthritic, a proximal row carpectomy (PRC) is contraindicated (as it requires a pristine capitate head to articulate with the lunate fossa). Therefore, scaphoid excision and four-corner arthrodesis is the treatment of choice.

Question 2350

Topic: Hand Trauma & Infection

A 32-year-old mechanic presents with an infected index finger after a puncture wound. You suspect pyogenic flexor tenosynovitis. Which of the following is NOT one of Kanavel's four cardinal signs of flexor tenosynovitis?

. Flexed resting posture of the digit
. Fusiform (sausage-like) swelling of the digit
. Severe pain with active flexion of the digit
. Tenderness along the course of the flexor tendon sheath
. Pain with passive extension of the digit

Correct Answer & Explanation

. Severe pain with active flexion of the digit

Explanation

Kanavel's four cardinal signs of pyogenic flexor tenosynovitis are: 1) Flexed resting posture of the digit, 2) Fusiform swelling of the digit, 3) Tenderness along the flexor tendon sheath, and 4) Pain with passive extension of the digit (often the earliest and most sensitive sign). Pain with active flexion is not considered one of the specific cardinal signs.

Question 2351

Topic: 7. Hand and Wrist
A 32-year-old male manual laborer presents with chronic dorsal wrist pain. Radiographs demonstrate sclerosis and severe fragmentation of the lunate, with proximal migration of the capitate and a radioscaphoid angle of 65 degrees. He is noted to have ulnar minus variance. Which Lichtman stage of Kienböck's disease does this represent?
. Stage II
. Stage IIIA
. Stage IIIB
. Stage IV
. Stage I

Correct Answer & Explanation

. Stage IIIB

Explanation

Lichtman Stage IIIB Kienböck's disease is characterized by lunate fragmentation/collapse combined with fixed rotation of the scaphoid (radioscaphoid angle > 60 degrees) and proximal migration of the capitate (carpal height collapse). Stage IIIA has lunate collapse but maintains normal carpal alignment. Stage IV involves secondary radiocarpal or midcarpal osteoarthritis.

Question 2352

Topic: Wrist & Carpus
A 48-year-old manual laborer presents with chronic wrist pain years after an untreated scapholunate ligament tear. Radiographs show joint space narrowing extending across the entire radioscaphoid articulation. The capitolunate and radiolunate joints appear completely preserved. What is the correct staging for this condition?
. SLAC Stage I
. SLAC Stage II
. SLAC Stage III
. SNAC Stage II
. SNAC Stage III

Correct Answer & Explanation

. SLAC Stage III

Explanation

Scapholunate Advanced Collapse (SLAC) occurs in predictable stages. Stage I involves arthrosis restricted to the radial styloid and scaphoid. Stage II involves the entire radioscaphoid joint. Stage III involves the capitolunate joint. The radiolunate joint is characteristically spared due to its concentric, spherical articulation.

Question 2353

Topic: 7. Hand and Wrist

A hand surgeon is repairing a complete laceration of the flexor digitorum profundus (FDP) tendon in Zone II. According to biomechanical studies, the tensile strength of the repair before clinical failure is most directly proportional to which of the following factors?

. The caliber (thickness) of the suture material used
. The number of core suture strands crossing the repair site
. The use of a running epitendinous suture
. The placement of the knot (inside versus outside the repair)
. The number of locking loops placed within the tendon substance

Correct Answer & Explanation

. The number of core suture strands crossing the repair site

Explanation

The overall tensile strength of a flexor tendon repair is most directly proportional to the number of core suture strands crossing the repair site (e.g., 4-strand vs 6-strand repairs). While epitendinous sutures improve gliding and add 10-20% strength, and locking loops improve grip, the primary determinant of load-to-failure is the number of core strands.

Question 2354

Topic: Wrist & Carpus

Three months after open reduction and internal fixation of a distal radius fracture with a volar locking plate, a patient develops a sudden inability to extend the interphalangeal joint of the thumb. What is the most common iatrogenic cause of this specific complication in the setting of volar plating?

. Excessive traction during reduction
. Ischemia from the surgical approach
. Prominent dorsal screws penetrating the dorsal cortex
. Direct intraoperative laceration of the tendon
. Attritional rupture over the distal edge of the volar plate

Correct Answer & Explanation

. Prominent dorsal screws penetrating the dorsal cortex

Explanation

Rupture of the extensor pollicis longus (EPL) tendon after volar plating of the distal radius is most commonly caused by dorsal screw prominence. Screws that are too long penetrate the dorsal cortex and cause mechanical attrition of the EPL tendon within the third extensor compartment. Attrition over the distal edge of the volar plate affects flexor tendons (like the FPL).

Question 2355

Topic: 7. Hand and Wrist
A 32-year-old manual laborer presents with dorsal wrist pain. Radiographs reveal sclerosis and fragmentation of the lunate without carpal collapse. Ulnar variance is determined to be minus 3 mm. Which of the following surgical interventions is most appropriate for this Lichtman Stage II Kienböck's disease?
. Proximal row carpectomy
. Ulnar shortening osteotomy
. Radial shortening osteotomy
. Scaphoid-trapezium-trapezoid (STT) fusion
. Total wrist arthrodesis

Correct Answer & Explanation

. Radial shortening osteotomy

Explanation

In Kienböck's disease with ulnar minus variance and no carpal collapse (Stage II or IIIA), joint-leveling procedures such as a radial shortening osteotomy (or ulnar lengthening) are indicated to decrease the compressive forces across the radiolunate joint and decompress the lunate.

Question 2356

Topic: Nerve & Tendon

An electromyographic (EMG) study reveals a Martin-Gruber anastomosis. Which of the following accurately describes the anatomic pathway of this common neural communication?

. Motor fibers cross from the median nerve to the ulnar nerve in the forearm
. Sensory fibers cross from the ulnar nerve to the median nerve in the forearm
. Motor fibers cross from the deep branch of the ulnar nerve to the median nerve in the hand
. Motor fibers cross from the median nerve to the ulnar nerve in the hand
. Sensory fibers cross between the superficial radial nerve and the dorsal ulnar sensory nerve

Correct Answer & Explanation

. Motor fibers cross from the median nerve to the ulnar nerve in the forearm

Explanation

A Martin-Gruber anastomosis is a common anatomical variant (present in roughly 15-20% of individuals) in which motor nerve fibers communicate from the median nerve (or its anterior interosseous branch) to the ulnar nerve in the proximal forearm. This anomaly can complicate the diagnosis of ulnar neuropathy at the elbow.

Question 2357

Topic: 7. Hand and Wrist
Flexor tendon lacerations of the hand are categorized into anatomic zones to guide prognosis and treatment. Which zone, containing both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons within a tight fibro-osseous sheath, is historically referred to as 'no man's land'?
. Zone I
. Zone II
. Zone III
. Zone IV
. Zone V

Correct Answer & Explanation

. Zone II

Explanation

Zone II extends from the distal palmar crease (the proximal edge of the A1 pulley) to the insertion of the FDS tendon in the middle phalanx. Because both the FDP and FDS tendons lie closely together within the narrow fibro-osseous flexor sheath, primary repair in this area historically had high rates of dense adhesions and poor functional outcomes, earning it the moniker 'no man's land' by Bunnell.

Question 2358

Topic: 7. Hand and Wrist

A 45-year-old female presents with recurrent numbness in her thumb, index, and middle fingers 6 months after an open carpal tunnel release. EMG confirms severe median neuropathy at the wrist, worse than preoperative levels. Surgical exploration reveals the median nerve is tethered by dense scar tissue, but the flexor retinaculum is fully released. Following neurolysis, which of the following is the most appropriate vascularized flap to prevent re-scarring?

. Radial forearm flap
. Hypothenar fat pad flap
. First dorsal metacarpal artery flap
. Cross finger flap
. Abductor pollicis brevis muscle flap

Correct Answer & Explanation

. Hypothenar fat pad flap

Explanation

The hypothenar fat pad flap is commonly used for recurrent carpal tunnel syndrome with severe perineural scarring. It provides a local, vascularized adipose tissue layer to wrap the median nerve, preventing re-tethering to the overlying structures and improving nerve gliding.

Question 2359

Topic: 7. Hand and Wrist

A 28-year-old male undergoes open reduction and internal fixation for a volar Barton's fracture. The surgeon must carefully stabilize the volar lunate facet fragment to prevent carpal subluxation. Which critical radiocarpal ligament originates from this specific fragment?

. Radioscaphocapitate ligament
. Long radiolunate ligament
. Short radiolunate ligament
. Radioscapholunate ligament (Ligament of Testut)
. Dorsal radiocarpal ligament

Correct Answer & Explanation

. Short radiolunate ligament

Explanation

The short radiolunate (SRL) ligament originates from the volar margin of the lunate facet of the distal radius and inserts onto the volar lunate. It is the primary stabilizer preventing volar subluxation of the lunate. Failure to fix this fragment allows the lunate to subluxate volarly with the fragment.

Question 2360

Topic: 7. Hand and Wrist

A 35-year-old man presents with inability to cross his fingers and a clawing deformity of the ring and little fingers following a deep glass laceration to the mid-forearm. In a normal hand, which of the following intrinsic muscles is primarily responsible for preventing this clawing posture?

. Flexor digitorum profundus
. Palmar interossei
. Dorsal interossei
. Lumbricals
. Flexor digitorum superficialis

Correct Answer & Explanation

. Lumbricals

Explanation

Clawing (hyperextension of MCP and flexion of IP joints) in an ulnar neuropathy occurs because the lumbricals to the ring and small fingers are denervated. The lumbricals normally flex the MCP and extend the IP joints. Loss of this function leaves the extensor digitorum communis unopposed at the MCP, and FDP/FDS unopposed at the IPs.

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