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7. Hand and Wrist MCQs

Practice Set 177 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 3521

Topic: Nerve & Tendon

A 42-year-old female assembly line worker presents with chronic, deep aching pain in her proximal lateral right forearm. She has failed 6 months of conservative management for presumed lateral epicondylitis. Examination reveals maximal tenderness 4 cm distal to the lateral epicondyle and pain exacerbated by resisted forearm supination with the elbow extended. There are no sensory deficits in the hand. If surgical decompression is performed, which of the following structures is the MOST common site of compression for the affected nerve?

. Arcade of Struthers
. Ligament of Struthers
. Arcade of Frohse
. Lacertus fibrosus
. Osborne's fascia

Correct Answer & Explanation

. Arcade of Frohse

Explanation

Correct Answer: C (Arcade of Frohse)This patient's presentation is classic for radial tunnel syndrome, which involves compression of the posterior interosseous nerve (PIN), a motor branch of the radial nerve. Symptoms include deep aching pain in the proximal lateral forearm, tenderness distal to the lateral epicondyle (unlike lateral epicondylitis, where tenderness is directly over the epicondyle), and pain with resisted supination. Because the PIN is a motor nerve, there are no sensory deficits. The most common site of PIN compression within the radial tunnel is the Arcade of Frohse, which is the proximal fibrous edge of the superficial head of the supinator muscle. The Arcade of Struthers and Osborne's fascia are associated with ulnar nerve compression (cubital tunnel). The Ligament of Struthers and Lacertus fibrosus (bicipital aponeurosis) are associated with median nerve compression (pronator syndrome).

Question 3522

Topic: 7. Hand and Wrist

A 42-year-old male undergoes a single-incision anterior approach for the repair of an acute distal biceps tendon rupture. Postoperatively, he complains of numbness and paresthesias along the lateral aspect of his forearm. Motor function of the hand and wrist is completely intact, and he has no pain with resisted wrist extension. Which nerve was most likely injured or stretched by retractors during the surgical exposure?

. Posterior interosseous nerve (PIN).
. Lateral antebrachial cutaneous (LABC) nerve.
. Superficial radial nerve.
. Median nerve.
. Ulnar nerve.

Correct Answer & Explanation

. Lateral antebrachial cutaneous (LABC) nerve.

Explanation

Correct Answer: Lateral antebrachial cutaneous (LABC) nerve.The lateral antebrachial cutaneous (LABC) nerve is the terminal sensory branch of the musculocutaneous nerve. It exits the deep fascia lateral to the biceps tendon in the distal arm and courses superficially over the brachioradialis to supply sensation to the lateral forearm. During a single-incision anterior approach for distal biceps repair, the LABC nerve is highly vulnerable to traction injury from lateral retractors. Injury results in sensory deficits along the lateral forearm, as described in the vignette. The posterior interosseous nerve (PIN) is a motor nerve at risk during the deep dissection (especially if retractors are placed blindly around the radial neck) or during a two-incision approach, but injury would cause weakness in finger/thumb extension, not isolated sensory loss. The superficial radial nerve is further distal and deep to the brachioradialis in this region.

Question 3523

Topic: Nerve & Tendon

During surgical decompression for recalcitrant cubital tunnel syndrome, the ulnar nerve is found to be compressed approximately 8 cm proximal to the medial epicondyle. Which of the following anatomic structures is responsible for this compression?

. Osborne's ligament
. Arcade of Struthers
. Medial intermuscular septum
. Aponeurosis of the flexor carpi ulnaris
. Ligament of Struthers

Correct Answer & Explanation

. Arcade of Struthers

Explanation

The Arcade of Struthers is a fascial band extending from the medial intermuscular septum to the medial head of the triceps, located about 8 cm proximal to the medial epicondyle. It is a known site of ulnar nerve compression, especially after anterior transposition.

Question 3524

Topic: 7. Hand and Wrist

After reduction of a shoulder dislocation, which of the following is MOST important to assess to ensure adequate blood supply to the hand?

. Capillary refill in the fingernails
. Sensation of the thumb pad
. Motor function of the intrinsic hand muscles
. Wrist extension strength
. Forearm supination strength

Correct Answer & Explanation

. Capillary refill in the fingernails

Explanation

Capillary refill is a quick and reliable indicator of peripheral perfusion and adequate blood supply to the extremity, including the hand. Diminished or delayed capillary refill suggests potential arterial compromise, which is critical to identify post-reduction. Sensation, motor function, and specific muscle strengths assess nerve integrity but not directly arterial blood flow to the hand.

Question 3525

Topic: 7. Hand and Wrist

When performing open reduction and internal fixation of a distal radius fracture with a volar locking plate, what is the most critical anatomical consideration to avoid iatrogenic injury during plate placement?

. Injury to the ulnar artery.
. Damage to the median nerve.
. Impingement of the extensor tendons, particularly EPL.
. Injury to the superficial radial nerve.
. Penetration of the dorsal cortex by excessively long screws.

Correct Answer & Explanation

. Penetration of the dorsal cortex by excessively long screws.

Explanation

While all options represent potential complications, penetration of the dorsal cortex by excessively long screws is a highly critical and common pitfall with volar plating of the distal radius. This can lead to significant irritation, attrition, and rupture of the extensor tendons, particularly the Extensor Pollicis Longus (EPL), which lies in close proximity to the dorsal cortex. Careful measurement and fluoroscopic verification are essential to avoid this. Median nerve injury is a risk during the approach, but not directly from plate placement itself if properly positioned. Extensor tendon impingement can also occur if the plate is placed too proximally or is prominent, but dorsal screw penetration is a more direct and severe cause of tendon damage specific to screw length.

Question 3526

Topic: 7. Hand and Wrist
A 25-year-old carpenter sustains a laceration over the volar aspect of the proximal phalanx of his index finger, cutting both the FDS and FDP tendons. According to Verdan's classification, which zone of flexor tendon injury does this represent?
. Zone I
. Zone II
. Zone III
. Zone IV
. Zone V

Correct Answer & Explanation

. Zone II

Explanation

Zone II (historically known as 'No Man's Land') extends from the A1 pulley (distal palmar crease) to the FDS insertion on the middle phalanx. Injuries here involve both FDS and FDP within the fibro-osseous sheath, complicating repair due to adhesion risk.

Question 3527

Topic: 7. Hand and Wrist

The predominant blood supply to the proximal pole of the scaphoid is derived from which of the following vessels?

. Superficial palmar branch of the radial artery
. Dorsal carpal branch of the radial artery
. Anterior interosseous artery
. Deep palmar arch
. Ulnar artery

Correct Answer & Explanation

. Dorsal carpal branch of the radial artery

Explanation

The scaphoid receives its primary vascular supply (70-80%) from the dorsal carpal branch of the radial artery, which enters at the distal third of the scaphoid and flows retrograde. This retrograde blood flow is why proximal pole fractures are at a high risk for avascular necrosis (AVN).

Question 3528

Topic: 7. Hand and Wrist

A 55-year-old female with long-standing, untreated carpal tunnel syndrome presents with severe thenar atrophy. Which of the following thumb muscles is typically spared in this condition because of its different innervation?

. Abductor pollicis brevis
. Opponens pollicis
. Superficial head of the flexor pollicis brevis
. Adductor pollicis
. First lumbrical

Correct Answer & Explanation

. Adductor pollicis

Explanation

The recurrent motor branch of the median nerve innervates the thenar muscles: Abductor Pollicis Brevis (APB), Opponens Pollicis (OP), and the superficial head of the Flexor Pollicis Brevis (FPB). Severe median nerve compression in the carpal tunnel leads to atrophy of these muscles. The Adductor Pollicis is innervated by the deep branch of the ulnar nerve and is therefore spared in carpal tunnel syndrome.

Question 3529

Topic: 7. Hand and Wrist

When using small fragment screws (e.g., 2.0 mm, 2.7 mm) for fixation in hand or foot fractures, which principle is paramount for preventing iatrogenic complications?

. Maximizing screw length to engage both cortices wherever possible.
. Ensuring meticulous soft tissue handling and minimal periosteal stripping.
. Using self-drilling screws exclusively to reduce surgical steps.
. Applying high torque during insertion to achieve maximum compression.
. Avoiding any form of countersinking to preserve bone stock.

Correct Answer & Explanation

. Ensuring meticulous soft tissue handling and minimal periosteal stripping.

Explanation

In the hand and foot, soft tissue structures (tendons, nerves, blood vessels) are very superficial and delicate. Meticulous soft tissue handling, minimal periosteal stripping, and precise screw placement are critical to prevent adhesions, nerve injury, and vascular compromise, which can lead to significant functional impairment. While bicortical fixation (A) is often desirable, it's not universally paramount above soft tissue considerations. Self-drilling screws (C) are a tool choice, not a universal principle. High torque (D) risks stripping or bone necrosis. Countersinking (E) is often beneficial to reduce irritation.

Question 3530

Topic: 7. Hand and Wrist

What is the primary principle behind most universal screw extraction systems (e.g., for stripped or broken screw heads)?

. To drill a larger pilot hole around the screw for easy removal.
. To use a reverse-threaded tap or conical extractor to gain purchase within the screw head.
. To apply significant axial pressure to push the screw out of the bone.
. To chemically dissolve the bone around the screw for extraction.
. To vibrate the screw loose using ultrasonic waves.

Correct Answer & Explanation

. To use a reverse-threaded tap or conical extractor to gain purchase within the screw head.

Explanation

Universal screw extraction systems (like screw extractors or reverse taps) are designed to engage with the damaged or stripped screw head. They typically have a reverse (left-handed) thread or a conical, fluted design. Once driven into the damaged driver recess or a pre-drilled central hole in a broken screw, turning the extractor counter-clockwise causes it to bite into the screw material, allowing the screw to be unscrewed from the bone. Drilling a larger pilot hole (A) is usually after failing to engage the screw head. Applying axial pressure (C), chemical dissolution (D), or ultrasonic vibration (E) are not standard primary extraction principles.

Question 3531

Topic: Wrist & Carpus

When using a volar locking plate for a distal radius fracture, the screws are typically inserted in which orientation relative to the articular surface?

. Perpendicular to the plate, avoiding the articular surface.
. Parallel to the joint surface, supporting subchondral bone.
. Oblique to the joint, aiming for bicortical fixation.
. From dorsal to volar, engaging only the volar cortex.
. With a variable angle, directed away from the fracture line.

Correct Answer & Explanation

. Parallel to the joint surface, supporting subchondral bone.

Explanation

Volar locking plates for distal radius fractures are designed with screw holes that allow the distal screws to be inserted at fixed or variable anglesparallelto the joint surface. This creates a 'subchondral raft' of screws that buttress and support the articular fragments, preventing their collapse and maintaining the reduction of the joint surface. While bicortical engagement is often desired, the primary orientation is subchondral support. Perpendicular (A) would violate the joint. Oblique (C) might be true for some variable angles, but thegoalis parallel to the joint. Dorsal to volar (D) is incorrect for a volar plate. Directed away from fracture (E) is too vague.

Question 3532

Topic: 7. Hand and Wrist
A 40-year-old manual laborer presents with chronic, progressive wrist pain localized to the dorsum of the wrist, particularly over the lunate, and weakness of grip. Radiographs show increased sclerosis and collapse of the lunate bone, with a negative ulnar variance. MRI confirms advanced avascular necrosis of the lunate (Lichtman Stage IIIA/IIIB). What is the most appropriate surgical management for this patient?
. Radial shortening osteotomy.
. Proximal row carpectomy.
. Excision of the lunate (lunatectomy).
. Wrist arthrodesis.
. Lunate revascularization with vascularized bone graft.

Correct Answer & Explanation

. Radial shortening osteotomy.

Explanation

Kienbรถck's disease is avascular necrosis of the lunate. Given the chronic pain, progressive collapse, and specifically the negative ulnar variance, a radial shortening osteotomy is an appropriate treatment. This procedure aims to unload the lunate by shortening the radius, thereby reducing compressive forces across the radiocarpal joint and potentially improving vascularity or preventing further collapse. Proximal row carpectomy or wrist arthrodesis are salvage procedures reserved for more advanced stages (Lichtman Stage IV) with significant arthritic changes. Lunatectomy alone is generally not recommended due to carpal instability. Lunate revascularization with vascularized bone graft is primarily considered for earlier stages (Lichtman Stage II) before significant collapse or sclerosis.

Question 3533

Topic: 7. Hand and Wrist

A 30-year-old carpenter presents with chronic wrist pain and limited range of motion after a fall on an outstretched hand 6 months prior. Radiographs show a scaphoid waist nonunion with evidence of proximal pole avascular necrosis (AVN). There is no significant carpal collapse (SNAC wrist not yet developed). What is the most appropriate surgical management?

. Excision of the proximal pole fragment.
. Vascularized bone graft and internal fixation.
. Non-vascularized bone graft and internal fixation.
. Proximal row carpectomy.
. Scaphoid fusion to the lunate.

Correct Answer & Explanation

. Vascularized bone graft and internal fixation.

Explanation

For a scaphoid waist nonunion with evidence of proximal pole avascular necrosis (AVN) and no significant carpal collapse, a vascularized bone graft (often harvested from the distal radius) combined with internal fixation (e.g., headless compression screw) is the preferred treatment. The vascularized graft provides a blood supply to the ischemic proximal pole, significantly improving the chances of union and revascularization while preserving carpal motion. A non-vascularized bone graft (Option C) is less effective in the presence of AVN. Excision of the proximal pole fragment (Option A) or proximal row carpectomy (Option D) are salvage procedures typically reserved for advanced degenerative changes or severe carpal collapse (SNAC/SLAC wrist). Scaphoid-lunate fusion (Option E) is not a standard treatment for scaphoid nonunion with AVN.

Question 3534

Topic: 7. Hand and Wrist

A 30-year-old construction worker presents with a severe crush injury to his dominant hand, resulting in a functionally irreparable ulnar nerve deficit at the wrist level (affecting all intrinsic muscles) and significant contracture of the fourth and fifth digits (ulnar claw hand). His median nerve is intact. What is the most appropriate tendon transfer to restore pinch and grip strength and address clawing in the ulnar-sided digits?

. ECRL to FDP for power grip
. Brachioradialis to FPL for thumb flexion
. FDS (ring finger) to the common intrinsic hood for intrinsic function (e.g., to lateral bands of ring/small fingers)
. PT to ECRB for wrist extension
. FCR to ECRL for wrist flexion balance

Correct Answer & Explanation

. FDS (ring finger) to the common intrinsic hood for intrinsic function (e.g., to lateral bands of ring/small fingers)

Explanation

For a high ulnar nerve palsy or irreparable lesion causing loss of intrinsic muscle function and clawing of the ring and small fingers, a common and effective tendon transfer is the use of the flexor digitorum superficialis (FDS) of the ring finger. This FDS tendon is often split and rerouted to provide motor power to restore intrinsic function (e.g., to the lateral bands of the ring and small fingers or a common intrinsic hood), thereby addressing both pinch and grip strength and correcting the claw deformity. This procedure aims to restore opposition of the thumb (via ADM/OP, often addressed by a separate transfer or as part of the FDS split) and prevent clawing of the ulnar two digits. The other options are for different deficits (wrist extension, thumb flexion) or are not primary intrinsic reconstructions for ulnar nerve palsy.

Question 3535

Topic: 7. Hand and Wrist

A 40-year-old male develops severe, unrelenting burning pain, allodynia, and trophic changes in his hand following a distal radius fracture, consistent with Complex Regional Pain Syndrome (CRPS) Type I. He is in the acute phase of CRPS. What is the most effective initial interventional pain management strategy for CRPS Type I in the acute phase?

. Oral NSAIDs.
. Oral gabapentin.
. Stellate ganglion block (sympathetic nerve block).
. Epidural steroid injection.
. Spinal cord stimulator implantation.

Correct Answer & Explanation

. Stellate ganglion block (sympathetic nerve block).

Explanation

In the acute phase of Complex Regional Pain Syndrome Type I (CRPS I) affecting the upper extremity, sympathetic nerve blocks, such as a stellate ganglion block, are considered a highly effective initial interventional treatment. These blocks aim to interrupt the pain-vasoconstriction cycle mediated by the sympathetic nervous system, providing significant pain relief and facilitating physical therapy, which is crucial for preventing disease progression. Oral medications like gabapentin or NSAIDs are often used as adjuncts, but blocks offer a more targeted and potent intervention in the acute setting. Spinal cord stimulators are reserved for refractory, chronic cases.

Question 3536

Topic: 7. Hand and Wrist

A 40-year-old carpenter sustains a severe right hand injury from a saw, resulting in complete transection of the ulnar nerve at the wrist, laceration of the flexor digitorum profundus (FDP) tendons to the ring and small fingers, and segmental bone loss of the proximal phalanx of the small finger. All other neurovascular structures are intact. What is the optimal initial surgical management strategy for this complex injury?

. Immediate single-stage repair of all structures, including nerve, tendons, and bone graft for phalanx.
. Delayed nerve repair (3-6 weeks) after initial wound debridement and tendon repair/bone fixation.
. Staged reconstruction, initially debridement, tendon repair, and external fixation for bone, with nerve repair at a later stage.
. Debridement, tendon repair, immediate bone grafting for the phalanx, and primary nerve repair.
. Amputation of the small finger to optimize function of the remaining digits.

Correct Answer & Explanation

. Debridement, tendon repair, immediate bone grafting for the phalanx, and primary nerve repair.

Explanation

This is a complex hand injury involving nerve, tendon, and bone. The goal of initial management is to achieve a stable, viable, and potentially functional hand. Debridement is always the first step in open injuries. Tendon repair (FDP) should generally be done primarily, if feasible, to optimize gliding and functional recovery. Bone loss of the proximal phalanx requires stabilization and restoration of length; immediate bone grafting (e.g., autograft) can be performed if soft tissue coverage is adequate and the wound is clean. Nerve repair (ulnar nerve): While traditionally delayed nerve repair was advocated, current evidence generally supportsprimary nerve repairfor sharp, clean lacerations, especially in the context of other repairs, to maximize axon regeneration and functional recovery. There is no benefit to delaying nerve repair for 3-6 weeks unless the wound is contaminated or soft tissue is significantly compromised. Single-stage repair of all structures is often the ideal approach, assuming wound conditions permit. Option C suggests delayed nerve repair, which is less optimal for clean lacerations. Option E (amputation) is overly aggressive given the potential for functional salvage. Therefore,debridement, tendon repair, immediate bone grafting for the phalanx, and primary nerve repair(D) represents the most comprehensive and optimal initial surgical strategy aiming for best functional outcome.

Question 3537

Topic: 7. Hand and Wrist

A 30-year-old active male presents with chronic ulnar-sided wrist pain, clicking, and weakness for 6 months, following a fall onto an outstretched hand. Clinical examination reveals tenderness over the triquetrum and a positive ulnar snuffbox test. Imaging shows a dynamic scapholunate dissociation and a complete tear of the triangular fibrocartilage complex (TFCC) central and foveal attachments, with positive drive-through test. Which surgical procedure is most likely to provide stable and lasting relief of his symptoms?

. Arthroscopic TFCC debridement.
. Open repair of the TFCC foveal attachment.
. Ulnar shortening osteotomy.
. Lunotriquetral (LT) ligament reconstruction.
. Four-corner arthrodesis.

Correct Answer & Explanation

. Open repair of the TFCC foveal attachment.

Explanation

The patient presents with chronic ulnar-sided wrist pain, clicking, and weakness, along with objective findings of a complete tear of the TFCC central and foveal attachments, a positive drive-through test, and tenderness over the triquetrum. This points to significant ulnar-sided wrist instability. While 'dynamic scapholunate dissociation' is also mentioned, the primary symptoms and the explicit complete TFCC tear are the most direct targets for intervention, especially as there is no specific scapholunate (SL) repair option provided. Arthroscopic TFCC debridement (A) is insufficient for a complete foveal tear. Ulnar shortening osteotomy (C) is for ulnar positive variance or impaction. LT ligament reconstruction (D) is for lunotriquetral instability, which might be a secondary issue, but the TFCC tear is a more primary structural disruption for ulnar-sided stability. Four-corner arthrodesis (E) is a salvage procedure for advanced arthritis. For a complete tear of the TFCC foveal attachment, which is critical for distal radioulnar joint and ulnar carpal stability,open repair of the TFCC foveal attachment (B)is the most appropriate procedure to restore stability and provide lasting relief from ulnar-sided wrist pain and mechanical symptoms. This directly addresses the main structural lesion causing instability on the ulnar side.

Question 3538

Topic: 7. Hand and Wrist
A 30-year-old construction worker presents with chronic wrist pain and weakness 1 year after a fall on an outstretched hand. Radiographs reveal a scaphoid nonunion with features of AVN (sclerosis of the proximal pole) and a significant humpback deformity (Minderhoud's angle < 30 degrees). What is the most appropriate surgical intervention?
. Excision of the proximal pole of the scaphoid.
. Dorsal screw fixation of the nonunion.
. Vascularized bone graft with internal fixation.
. Scaphoid replacement arthroplasty.
. Proximal row carpectomy.

Correct Answer & Explanation

. Vascularized bone graft with internal fixation.

Explanation

This patient has a chronic scaphoid nonunion with AVN of the proximal pole and a humpback deformity, indicating a high risk of continued nonunion and carpal collapse (SNAC wrist). In such cases, a vascularized bone graft is crucial to reintroduce blood supply to the avascular proximal pole and promote healing, combined with internal fixation to maintain reduction and compression. Dorsal screw fixation alone is insufficient if AVN is present. Excision of the proximal pole or proximal row carpectomy are salvage procedures for established SNAC wrist. Scaphoid replacement arthroplasty is also a salvage option, generally for older patients or failed reconstructions. Vascularized bone graft provides the best chance for healing and restoration of anatomy in this scenario.

Question 3539

Topic: Nerve & Tendon

A 30-year-old male presents with progressive right elbow pain, numbness and tingling in the ring and small fingers, and weakness of intrinsic hand muscles. Clinical examination reveals a positive Tinel's sign at the cubital tunnel, severe ulnar nerve subluxation with elbow flexion, and significant intrinsic muscle wasting. What is the most appropriate surgical management?

. In situ ulnar nerve decompression.
. Medial epicondylectomy.
. Anterior subcutaneous ulnar nerve transposition.
. Anterior submuscular ulnar nerve transposition.
. Posterior ulnar nerve transposition.

Correct Answer & Explanation

. Anterior submuscular ulnar nerve transposition.

Explanation

For severe cubital tunnel syndrome with chronic symptoms, intrinsic muscle wasting, and particularly, gross ulnar nerve subluxation, in situ decompression alone is often insufficient and may lead to recurrent symptoms. Anterior submuscular ulnar nerve transposition is generally preferred in cases of severe compression, prior failed surgery, or significant instability/subluxation of the nerve, as it provides a more robust and stable environment for the nerve and is thought to offer better protection. Medial epicondylectomy can also decompress but does not address subluxation. Anterior subcutaneous transposition may be simpler but offers less protection and stability than submuscular for severe cases. Posterior transposition is not a standard approach.

Question 3540

Topic: 7. Hand and Wrist
A 35-year-old male, a keen weightlifter, presents with chronic dorsal wrist pain and weakness 6 months after a fall onto an outstretched hand. Radiographs reveal a widened scapholunate gap (>3mm) and a 'Terry Thomas' sign. Dynamic imaging confirms scapholunate dissociation. What is the most appropriate surgical intervention for chronic, reducible scapholunate instability with preserved articular cartilage?
. Scapholunate ligament repair (direct repair)
. Scaphoid excision and four-corner fusion
. SLAC wrist reconstruction (proximal row carpectomy)
. Ligament reconstruction using a tendon graft (e.g., Blatt capsulodesis, modified Brunelli)
. Wrist arthrodesis

Correct Answer & Explanation

. Ligament reconstruction using a tendon graft (e.g., Blatt capsulodesis, modified Brunelli)

Explanation

For chronic, reducible scapholunate instability with preserved articular cartilage, direct repair of the scapholunate ligament is often not feasible due to chronic tissue attenuation. Therefore, ligament reconstruction using a local tendon graft (e.g., FCR, palmaris longus) or capsulodesis (e.g., Blatt capsulodesis, modified Brunelli) is a common and effective surgical option to restore stability. Scaphoid excision and four-corner fusion or proximal row carpectomy (SLAC wrist reconstruction) are salvage procedures reserved for later stages of scapholunate advanced collapse (SLAC wrist), which involves significant arthritis. Wrist arthrodesis is a definitive salvage for end-stage arthritis or instability.

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