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7. Hand and Wrist MCQs

Practice Set 116 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 2301

Topic: Wrist & Carpus

A 24-year-old gymnast presents with ulnar-sided wrist pain. Examination reveals a positive ballottement test (Reagan test). Radiographs show a volar flexed scaphoid and lunate with a dorsally extended triquetrum. What is the most likely diagnosis?

. Scapholunate dissociation (DISI)
. Lunotriquetral dissociation (VISI)
. Midcarpal instability
. Triangular fibrocartilage complex (TFCC) tear
. Perilunate dislocation

Correct Answer & Explanation

. Lunotriquetral dissociation (VISI)

Explanation

Lunotriquetral (LT) ligament tears lead to Volar Intercalated Segment Instability (VISI). The lunate flexes with the scaphoid while the triquetrum extends. The Reagan test (LT ballottement) is positive. Scapholunate tears lead to DISI (Dorsal Intercalated Segment Instability).

Question 2302

Topic: 7. Hand and Wrist

A 42-year-old female presents with volar forearm pain and numbness in her thumb, index, and middle fingers. The physician suspects Pronator Syndrome rather than Carpal Tunnel Syndrome (CTS). Which clinical finding strongly supports a diagnosis of Pronator Syndrome over CTS?

. A positive Tinel's sign at the wrist
. Atrophy of the thenar eminence
. Decreased sensation over the thenar eminence
. Worsening of symptoms at night
. Positive Phalen's test

Correct Answer & Explanation

. Decreased sensation over the thenar eminence

Explanation

The palmar cutaneous branch of the median nerve provides sensation to the thenar eminence and branches off proximal to the carpal tunnel. Sensation over the thenar eminence is preserved in Carpal Tunnel Syndrome but is decreased in proximal median nerve entrapment neuropathies like Pronator Syndrome.

Question 2303

Topic: 7. Hand and Wrist

Flexor tendon injuries in the hand are classified by anatomical zones, each with distinct prognostic implications. Historically termed 'no man's land' due to poor surgical outcomes, Zone II encompasses which of the following anatomic boundaries?

. From the muscle-tendon junction to the proximal edge of the carpal tunnel
. From the proximal edge of the carpal tunnel to the distal palmar crease
. From the A1 pulley (distal palmar crease) to the insertion of the FDS tendon
. From the insertion of the FDS tendon to the insertion of the FDP tendon
. From the distal interphalangeal joint to the fingertip

Correct Answer & Explanation

. From the proximal edge of the carpal tunnel to the distal palmar crease

Explanation

Flexor tendon Zone II begins proximally at the level of the A1 pulley (approximating the distal palmar crease) and ends distally at the insertion of the flexor digitorum superficialis (FDS) on the middle phalanx. It is called 'no man's land' because both the FDS and FDP travel tightly together within the fibro-osseous sheath, making adhesions common after injury and repair.

Question 2304

Topic: 7. Hand and Wrist

A hand surgeon performing an open carpal tunnel release under local anesthesia notices that despite a perfect median nerve block at the wrist, the patient retains robust thumb opposition and the thenar muscles continue to contract. The surgeon suspects an anomalous neural innervation pattern. The Martin-Gruber anastomosis is a common anatomical variant that typically involves a crossing of motor fibers from which nerve to which nerve in the forearm?

. Ulnar nerve to median nerve
. Median nerve to ulnar nerve
. Radial nerve to median nerve
. Median nerve to radial nerve
. Ulnar nerve to radial nerve

Correct Answer & Explanation

. Median nerve to ulnar nerve

Explanation

The Martin-Gruber anastomosis is a communicating neural branch in the forearm, present in up to 15-20% of the population. It carries motor fibers originating from the median nerve (or anterior interosseous nerve) across to the ulnar nerve. These fibers often go on to innervate the intrinsic muscles of the hand (including thenar muscles in anomalous cases), confusing the clinical picture of nerve blocks or compression neuropathies.

Question 2305

Topic: 7. Hand and Wrist

Idiopathic avascular necrosis of the scaphoid is known as Preiser disease. Which of the following vascular anatomical features most directly makes the scaphoid proximal pole susceptible to avascular necrosis?

. The dorsal carpal branch of the radial artery enters distally and supplies the proximal pole in a retrograde fashion
. The palmar carpal branch of the ulnar artery supplies the proximal pole but is frequently absent
. The anterior interosseous artery terminates at the waist, leaving the proximal pole in a watershed zone
. The superficial palmar arch provides the sole blood supply via tenuous intraosseous vessels
. The deep palmar arch vessels enter dorsally and are prone to disruption during wrist flexion

Correct Answer & Explanation

. The dorsal carpal branch of the radial artery enters distally and supplies the proximal pole in a retrograde fashion

Explanation

The scaphoid relies heavily on branches of the radial artery (predominantly the dorsal carpal branch). These vessels enter the bone at the dorsal ridge, which is distal to the waist, and course in a retrograde direction to perfuse the proximal pole. This retrograde blood supply is easily compromised by fractures at the waist or proximal pole, leading to avascular necrosis.

Question 2306

Topic: 7. Hand and Wrist

During surgical exposure for a complex zone II flexor tendon repair, the surgeon must decide which portions of the digital flexor sheath to vent. Preserving which of the following combinations of pulleys is biomechanically most critical to prevent digital bowstringing and loss of flexion work efficiency?

. A1 and A3
. A1 and A5
. A2 and A4
. A3 and A5
. C1 and C3

Correct Answer & Explanation

. A2 and A4

Explanation

The flexor tendon pulley system prevents bowstringing of the tendons across the interphalangeal joints. The A2 pulley (located over the proximal phalanx) and the A4 pulley (located over the middle phalanx) are mechanically the most crucial. Loss of these pulleys leads to significant bowstringing, decreased range of motion, and decreased mechanical efficiency (increased work of flexion).

Question 2307

Topic: 7. Hand and Wrist
A 52-year-old male presents with chronic wrist pain and is diagnosed with Scaphoid Nonunion Advanced Collapse (SNAC). Radiographs reveal advanced osteoarthritic changes in the radioscaphoid and capitolunate joints, while the radiolunate joint is completely spared. Which of the following salvage procedures is strictly contraindicated in this patient?
. Four-corner fusion with scaphoid excision
. Proximal row carpectomy (PRC)
. Total wrist arthrodesis
. Scaphoid excision and partial wrist denervation
. Midcarpal fusion

Correct Answer & Explanation

. Proximal row carpectomy (PRC)

Explanation

Proximal row carpectomy (PRC) relies on a preserved, cartilaginous articulation between the head of the capitate and the lunate fossa of the distal radius. In this patient, the presence of capitolunate arthritis (a feature of advanced SNAC/SLAC stage III) makes PRC strictly contraindicated. A four-corner fusion or total wrist arthrodesis would be more appropriate.

Question 2308

Topic: Wrist & Carpus

In a patient with negative ulnar variance, which of the following best describes the altered biomechanics across the radiocarpal joint that predisposes the patient to Kienbock's disease?

. Increased load transmission across the radioscaphoid fossa.
. Decreased load transmission through the triangular fibrocartilage complex, resulting in lunate overload on the radius.
. Increased volar intercalated segment instability (VISI) leading to shear stress.
. Decreased vascularity of the palmar intercarpal ligaments.
. Ulnocarpal abutment causing secondary lunate necrosis.

Correct Answer & Explanation

. Decreased load transmission through the triangular fibrocartilage complex, resulting in lunate overload on the radius.

Explanation

Negative ulnar variance decreases the normal load borne by the ulnocarpal joint and triangular fibrocartilage complex (which is normally about 20%). This disproportionately increases the compressive forces transmitted from the distal radius to the lunate, leading to mechanical overload, microtrauma, and predisposing the lunate to avascular necrosis (Kienbock's disease).

Question 2309

Topic: 7. Hand and Wrist

When performing a fasciotomy for suspected compartment syndrome of the hand, how many dorsal incisions are typically required to decompress the interosseous compartments, and where are they optimally placed?

. Two incisions; placed over the 2nd and 4th metacarpals
. Two incisions; placed over the 3rd and 5th metacarpals
. Three incisions; placed over the 2nd, 3rd, and 4th metacarpals
. Four incisions; placed over each intermetacarpal space
. One transverse incision across the dorsal metacarpal bases

Correct Answer & Explanation

. Two incisions; placed over the 2nd and 4th metacarpals

Explanation

There are 10 compartments in the hand (4 dorsal interossei, 3 volar interossei, adductor pollicis, hypothenar, thenar). The standard dorsal approach for decompressing the interosseous compartments involves two longitudinal incisions: one placed over the 2nd metacarpal and one over the 4th metacarpal. This allows access to both the dorsal and volar interossei via the intermetacarpal spaces.

Question 2310

Topic: Wrist & Carpus

A 45-year-old construction worker presents with chronic wrist pain. Radiographs reveal a scaphoid nonunion advanced collapse (SNAC). Which of the following findings is an absolute contraindication to performing a proximal row carpectomy (PRC)?

. Scapholunate advanced collapse (SLAC) Stage II
. Capitate proximal pole degenerative changes
. Scaphoid nonunion advanced collapse (SNAC) Stage I
. Isolated radioscaphoid arthritis
. Dorsal intercalated segment instability (DISI) without arthritis

Correct Answer & Explanation

. Capitate proximal pole degenerative changes

Explanation

Proximal row carpectomy (PRC) relies on creating a new articulation between the lunate fossa of the distal radius and the proximal pole of the capitate. Therefore, any pre-existing degenerative changes or arthritis at the proximal pole of the capitate (or the lunate fossa) are an absolute contraindication to PRC. In such cases, a four-corner fusion (which relies on an intact radiolunate joint) is typically the preferred salvage procedure.

Question 2311

Topic: Nerve & Tendon
A patient presents with a chronic Boutonniere deformity following an untreated injury to the extensor mechanism of the finger. The development of this deformity is mechanically driven by the rupture or attenuation of the central slip, followed by which of the following biomechanical shifts?
. Rupture of the terminal extensor slip
. Volar subluxation of the lateral bands
. Dorsal subluxation of the lateral bands
. Rupture of the sagittal band
. Avulsion of the volar plate

Correct Answer & Explanation

. Volar subluxation of the lateral bands

Explanation

A Boutonniere deformity is characterized by proximal interphalangeal (PIP) joint flexion and distal interphalangeal (DIP) joint hyperextension. It is initiated by the disruption of the central slip of the extensor tendon (Zone III). This failure allows the triangular ligament to attenuate, leading to the volar (palmar) subluxation of the lateral bands past the axis of rotation of the PIP joint. The lateral bands then become flexors of the PIP joint while continuing to exert a hyperextension force on the DIP joint.

Question 2312

Topic: 7. Hand and Wrist
A 50-year-old construction worker presents with chronic wrist pain and a history of remote trauma. Radiographs reveal scapholunate advanced collapse (SLAC). According to the predictable progression of SLAC, which articulation is characteristically spared from degenerative changes, allowing for salvage procedures such as a four-corner fusion?
. Radioscaphoid joint
. Capitolunate joint
. Scaphotrapezial joint
. Radiolunate joint
. Scaphocapitate joint

Correct Answer & Explanation

. Radiolunate joint

Explanation

In SLAC wrist, arthritis predictably progresses from the radial styloid-scaphoid (Stage I) to the entire radioscaphoid joint (Stage II), and then to the capitolunate joint (Stage III). The radiolunate joint is characteristically spared because of its concentric, congruent articulation, which makes motion-preserving salvage procedures like proximal row carpectomy or four-corner fusion possible.

Question 2313

Topic: Nerve & Tendon
A 25-year-old rugby player presents with the inability to flex the distal interphalangeal (DIP) joint of his right ring finger after grasping an opponent's jersey. Radiographs are negative for a fracture. Ultrasound demonstrates the flexor digitorum profundus (FDP) tendon retracted to the level of the palm. What is the Leddy-Packer classification of this injury and the optimal timing for surgical repair?
. Type I, requiring surgery within 7-10 days
. Type II, requiring surgery within 7-10 days
. Type III, requiring surgery within 3-4 weeks
. Type I, requiring surgery within 3-4 weeks
. Type II, requiring surgery within 3-4 weeks

Correct Answer & Explanation

. Type I, requiring surgery within 7-10 days

Explanation

This is a Type I Leddy-Packer FDP avulsion (Jersey finger), where the tendon retracts completely into the palm. Because both vincula (longa and brevia) are ruptured, the tendon loses its blood supply and undergoes rapid necrosis and contraction. It must be repaired early, ideally within 7 to 10 days. Type II injuries retract to the level of the proximal interphalangeal (PIP) joint (vincula intact) and can be repaired up to a few weeks later. Type III involves a large bony avulsion that gets caught at the A4 pulley.

Question 2314

Topic: Nerve & Tendon

A 45-year-old carpenter presents with progressive weakness of the intrinsic hand muscles and numbness isolated to his ring and small fingers. Examination reveals a positive Tinel's sign approximately 8 cm proximal to the medial epicondyle. Which of the following structures is most likely compressing the involved nerve at this specific location?

. Osborne's ligament
. Arcade of Struthers
. Ligament of Struthers
. Lacertus fibrosus
. Aponeurosis of the two heads of the flexor carpi ulnaris

Correct Answer & Explanation

. Arcade of Struthers

Explanation

The patient has ulnar neuropathy. While the most common site of compression is at the cubital tunnel (Osborne's ligament / between the two heads of the FCU), compression can also occur proximally at the Arcade of Struthers. The Arcade of Struthers is a fascial band extending from the medial head of the triceps to the medial intermuscular septum, located approximately 8 cm proximal to the medial epicondyle. (Note: The Ligament of Struthers is associated with median nerve compression at the supracondylar process).

Question 2315

Topic: Wrist & Carpus
A 50-year-old manual laborer complains of chronic wrist pain. Radiographs demonstrate advanced joint space narrowing between the radius and the scaphoid, as well as narrowing between the capitate and the lunate. The radiolunate joint space is perfectly preserved. This radiographic appearance is pathognomonic for which stage of Scapholunate Advanced Collapse (SLAC)?
. Stage I
. Stage II
. Stage III
. Stage IV
. SNAC Stage II

Correct Answer & Explanation

. Stage III

Explanation

SLAC wrist progresses in a predictable pattern. Stage I involves the radial styloid and scaphoid. Stage II involves the entire radioscaphoid fossa. Stage III involves proximal migration of the capitate with capitolunate arthritis. The radiolunate joint is characteristically spared due to the concentric shape of the articulation, even in Stage III. Stage IV (controversial) implies pancarpal arthritis including the radiolunate joint.

Question 2316

Topic: 7. Hand and Wrist

A 35-year-old carpenter presents with a swollen, painful index finger 3 days after a penetrating injury. The surgeon suspects acute pyogenic flexor tenosynovitis. Which of the following is NOT one of Kanavel's four cardinal signs of this condition?

. Fusiform swelling of the entire digit
. Severe tenderness along the course of the flexor tendon sheath
. Erythema extending proximal to the wrist crease
. Excruciating pain with passive extension of the digit
. Resting posture of the digit in slight flexion

Correct Answer & Explanation

. Erythema extending proximal to the wrist crease

Explanation

Kanavel's four cardinal signs are: 1) Fusiform swelling (sausage digit), 2) Tenderness along the flexor tendon sheath, 3) Pain with passive extension (most sensitive early sign), and 4) Resting posture of the digit in flexion. Erythema extending proximal to the wrist crease is not a cardinal sign and may indicate a more extensive cellulitis or a deep space infection of the hand/forearm (Parona's space).

Question 2317

Topic: 7. Hand and Wrist
A 45-year-old carpenter presents with forearm pain and an inability to make an 'OK' sign (unable to flex the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger). Sensation over the entire hand is intact. Given this clinical presentation, which of the following muscles will maintain normal motor strength?
. Flexor pollicis longus
. Flexor digitorum profundus to the index finger
. Pronator quadratus
. Flexor carpi radialis
. Flexor digitorum profundus to the middle finger

Correct Answer & Explanation

. Flexor carpi radialis

Explanation

The patient has Anterior Interosseous Nerve (AIN) syndrome, evidenced by the inability to make an 'OK' sign (loss of FPL and FDP to the index finger) with spared sensation. The AIN is a purely motor branch of the median nerve. It innervates the FPL, FDP to the index and middle fingers, and the pronator quadratus. The flexor carpi radialis (FCR) is innervated by the main trunk of the median nerve proximal to the branching of the AIN, so its strength will be normal.

Question 2318

Topic: 7. Hand and Wrist

In a patient with a high radial nerve palsy, tendon transfer surgery is planned to restore wrist and finger extension. To restore robust wrist extension, the pronator teres (PT) is most commonly transferred to which of the following tendons, and for what specific biomechanical reason?

. Extensor carpi radialis longus (ECRL) to prevent radial deviation
. Extensor carpi radialis brevis (ECRB) due to its central insertion on the 3rd metacarpal base
. Extensor carpi ulnaris (ECU) to maintain ulnar variance
. Extensor digitorum communis (EDC) to restore simultaneous wrist and finger extension
. Flexor carpi radialis (FCR) as a direct antagonist

Correct Answer & Explanation

. Extensor carpi radialis brevis (ECRB) due to its central insertion on the 3rd metacarpal base

Explanation

To restore wrist extension in radial nerve palsy, the pronator teres (PT) is universally transferred to the extensor carpi radialis brevis (ECRB). The ECRB inserts on the base of the 3rd metacarpal, providing a central, balanced wrist extension. If the PT were transferred to the ECRL (which inserts on the 2nd metacarpal), it would result in excessive and undesirable radial deviation of the wrist during extension.

Question 2319

Topic: Nerve & Tendon

The Martin-Gruber anastomosis is a well-documented anatomical variant involving communicating neural branches. Which of the following best describes the most common neural transmission pathway in this anomaly?

. Ulnar nerve fibers crossing to the median nerve in the forearm to innervate the thenar eminence
. Median nerve fibers crossing to the ulnar nerve in the forearm to innervate the intrinsic hand muscles
. Radial nerve fibers crossing to the median nerve in the arm to innervate the lumbricals
. Median nerve fibers crossing to the radial nerve in the forearm to innervate the wrist extensors
. Ulnar nerve fibers crossing to the median nerve in the hand to innervate the superficial head of the flexor pollicis brevis

Correct Answer & Explanation

. Median nerve fibers crossing to the ulnar nerve in the forearm to innervate the intrinsic hand muscles

Explanation

The Martin-Gruber anastomosis occurs in the proximal forearm and involves motor fibers crossing from the median nerve (often via the anterior interosseous nerve) to the ulnar nerve. These fibers typically travel down the ulnar nerve to innervate intrinsic muscles of the hand (such as the first dorsal interosseous, adductor pollicis, and hypothenar muscles) that are normally supplied by the ulnar nerve.

Question 2320

Topic: 7. Hand and Wrist

A 45-year-old male presents with chronic wrist pain and a known scaphoid nonunion. Radiographs show arthritic changes involving the radioscaphoid joint and midcarpal joint (capitolunate), but the radiolunate joint is preserved. What is the most appropriate surgical treatment?

. Scaphoid ORIF with vascularized bone graft
. Proximal row carpectomy
. Four-corner fusion with scaphoid excision
. Total wrist arthrodesis
. Radial styloidectomy

Correct Answer & Explanation

. Four-corner fusion with scaphoid excision

Explanation

This patient has Scaphoid Nonunion Advanced Collapse (SNAC) stage 3, which involves arthritis of the radioscaphoid and capitolunate joints, while sparing the radiolunate joint. Proximal row carpectomy (PRC) relies on a pristine capitate head articulating with the lunate fossa; therefore, PRC is contraindicated when the capitate is arthritic. Four-corner fusion (capitate, lunate, triquetrum, hamate) with scaphoid excision is the treatment of choice as it relies on the preserved radiolunate articulation.

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