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7. Hand and Wrist MCQs

Practice Set 188 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 3741

Topic: Wrist & Carpus

Which of the following factors significantly increases the likelihood of a lunate dislocation requiring open reduction and internal fixation rather than successful closed reduction?

. Patient age under 30 years
. Injury sustained in a low-energy mechanism
. Presentation to the emergency department within 6 hours of injury
. Associated scaphoid fracture (trans-scaphoid perilunate dislocation)
. Absence of median nerve symptoms

Correct Answer & Explanation

. Associated scaphoid fracture (trans-scaphoid perilunate dislocation)

Explanation

An associated scaphoid fracture (trans-scaphoid perilunate dislocation) significantly complicates closed reduction. The presence of a fracture fragment prevents smooth reduction and often requires open reduction to stabilize the fracture and repair associated ligaments, even if initial closed reduction of the dislocation seems possible. The other options generally favor successful closed reduction or are less of a contraindication to closed reduction attempts.

Question 3742

Topic: 7. Hand and Wrist
What is the term for chronic carpal instability characterized by progressive degeneration of the scaphoid, lunate, and radius articulation, often a sequela of an untreated or inadequately treated scapholunate dissociation or perilunate injury?
. Kienböck's disease
. De Quervain's tenosynovitis
. SLAC wrist
. TFCC tear
. Ganglion cyst

Correct Answer & Explanation

. SLAC wrist

Explanation

SLAC wrist (Scapholunate Advanced Collapse) is a specific pattern of degenerative arthritis that results from chronic scapholunate dissociation or perilunate instability. It progresses through stages, starting with arthritis between the scaphoid and radial styloid, then progressing to the entire radioscaphoid joint, and eventually affecting the capitolunate joint, with relative sparing of the radiolunate joint until late stages. Kienböck's disease is avascular necrosis of the lunate, De Quervain's is tenosynovitis, TFCC tear is a cartilaginous injury, and a ganglion cyst is a soft tissue mass.

Question 3743

Topic: 7. Hand and Wrist

A patient presents with a chronic lunate dislocation (over 3 months old) and severe wrist pain, significantly impacting activities of daily living. Radiographs show marked degenerative changes. Which of the following salvage procedures is generally considered in such a case?

. Scapholunate ligament repair
. Limited wrist arthrodesis (e.g., scaphoid-trapezium-trapezoid fusion)
. Proximal row carpectomy
. Radial shortening osteotomy
. Excision of the lunate

Correct Answer & Explanation

. Proximal row carpectomy

Explanation

For chronic lunate dislocations with significant degenerative changes and pain, a proximal row carpectomy (PRC) is a common salvage procedure. PRC involves excising the scaphoid, lunate, and triquetrum, allowing the capitate to articulate directly with the distal radius. This provides pain relief and preserves a functional range of motion when reconstructive options are no longer viable. Ligament repair is unsuitable for chronic cases with arthritis. Limited arthrodesis might be considered for specific types of instability but PRC is more commonly chosen for diffuse degeneration post-dislocation. Wrist arthrodesis is a more extensive salvage with complete loss of motion. Radial shortening is for ulnar-negative variance. Excision of the lunate alone is not a standard procedure for chronic dislocation and would lead to collapse.

Question 3744

Topic: 7. Hand and Wrist

In the context of carpal instability, what does 'DISI' stand for and what is its characteristic radiographic appearance?

. Dorsal Interosseous Segmental Instability; volar tilt of the lunate
. Dynamic Instability of Scaphoid-Intercarpal; widening of the scapholunate gap on stress views
. Dorsal Intercalated Segmental Instability; dorsal tilt of the lunate
. Distal Intercarpal Subluxation Index; dorsal displacement of the capitate
. Direct Isolated Scapholunate Instability; normal capitolunate angle

Correct Answer & Explanation

. Dorsal Intercalated Segmental Instability; dorsal tilt of the lunate

Explanation

DISI stands for Dorsal Intercalated Segmental Instability. It is characterized by a dorsal tilt or extension of the lunate (seen as an increased scapholunate angle >60 degrees and an increased capitolunate angle >30 degrees on a lateral radiograph). This pattern is commonly associated with scapholunate ligament disruption. Volar tilt of the lunate (VISI) is associated with lunotriquetral ligament disruption.

Question 3745

Topic: 7. Hand and Wrist

When attempting closed reduction of an acute lunate dislocation, what is the initial maneuver typically employed after achieving adequate anesthesia?

. Direct pressure on the volar aspect of the lunate to push it dorsally
. Hyperflexion of the wrist with traction
. Hyperextension of the wrist with traction to unlock the lunate, followed by volar pressure and flexion
. Rotation of the forearm to supination
. Distraction of the carpometacarpal joints

Correct Answer & Explanation

. Hyperextension of the wrist with traction to unlock the lunate, followed by volar pressure and flexion

Explanation

The classic maneuver for reducing a lunate dislocation involves applying longitudinal traction to the hand, hyperextending the wrist to disengage or 'unlock' the lunate from under the capitate, then applying direct volar pressure over the lunate while simultaneously flexing the wrist to push the lunate back into its radial fossa. This sequence is critical for successful reduction. Direct volar pressure alone or hyperflexion initially would be ineffective or even counterproductive.

Question 3746

Topic: 7. Hand and Wrist

What is the primary role of K-wire fixation after open reduction of a lunate or perilunate dislocation?

. To provide definitive bony union of carpal fractures
. To compress articular fragments
. To provide temporary stability to maintain carpal alignment while ligamentous healing occurs
. To stimulate bone growth
. To prevent median nerve compression

Correct Answer & Explanation

. To provide temporary stability to maintain carpal alignment while ligamentous healing occurs

Explanation

K-wires (Kirschner wires) are used to provide temporary internal fixation and maintain the reduction of the carpal bones and the repaired ligaments. They act as internal splints, holding the carpus in the anatomically reduced position while the soft tissues (ligaments and capsule) heal. They do not provide definitive bony union (unless used for a specific fracture), compress articular fragments, stimulate bone growth, or directly prevent nerve compression (though successful reduction indirectly aids nerve decompression).

Question 3747

Topic: 7. Hand and Wrist

Which of the following physical examination findings is most indicative of acute median nerve compression in a patient with a wrist injury?

. Pain with resisted wrist extension
. Ecchymosis and swelling over the dorsal wrist
. Loss of sensation in the small finger
. Paresthesias and numbness in the thumb, index, and middle fingers
. Crepitus with forearm rotation

Correct Answer & Explanation

. Paresthesias and numbness in the thumb, index, and middle fingers

Explanation

Paresthesias and numbness in the median nerve distribution (thumb, index, middle, and radial half of the ring finger) are the classic signs of acute median nerve compression, such as that caused by a lunate dislocation. Pain with wrist extension might indicate tendonitis or extensor injury. Dorsal swelling is non-specific. Loss of sensation in the small finger suggests ulnar nerve involvement. Crepitus with forearm rotation points to distal radioulnar joint (DRUJ) injury or fracture.

Question 3748

Topic: Wrist & Carpus

When evaluating a lateral wrist radiograph, what normal alignment feature, when disrupted, suggests a perilunate or lunate dislocation?

. The normal alignment of the radial styloid with the scaphoid
. The articulation of the pisiform with the triquetrum
. The 'three-arc' alignment of Gilula's lines
. The collinear relationship of the radius, lunate, and capitate
. The normal ulnar variance

Correct Answer & Explanation

. The collinear relationship of the radius, lunate, and capitate

Explanation

On a true lateral wrist radiograph, the radius, lunate, and capitate should appear collinear, forming a continuous 'column.' Disruption of this collinear relationship, particularly the lunate displacing volarly or the capitate displacing dorsally relative to the lunate, is a hallmark of lunate or perilunate dislocations. Gilula's lines are assessed on an AP view to evaluate carpal alignment. Radial styloid-scaphoid articulation and pisiform-triquetrum articulation are important but not the primary indicator on a lateral for this specific injury. Ulnar variance relates to distal radius and ulna length.

Question 3749

Topic: 7. Hand and Wrist

A patient with a chronic, untreated lunate dislocation presents with severe pain and functional limitation. Surgical options are being discussed. What is a significant contraindication for performing a proximal row carpectomy (PRC) in this scenario?

. Pre-existing mild osteoarthritis of the thumb CMC joint
. Age greater than 60 years
. Significant chondral damage to the capitate head or distal radial lunate fossa
. Presence of a stable, healed scaphoid fracture
. History of carpal tunnel syndrome

Correct Answer & Explanation

. Significant chondral damage to the capitate head or distal radial lunate fossa

Explanation

Significant chondral damage to the capitate head or the lunate fossa of the distal radius is a major contraindication for a proximal row carpectomy (PRC). For a PRC to be successful, the articulating surfaces of the capitate (which will then articulate with the radius) and the lunate fossa of the distal radius must have relatively preserved cartilage. If these surfaces are already severely arthritic, a PRC will likely lead to continued pain and poor outcomes, making wrist arthrodesis a more appropriate salvage procedure. Other options are generally not contraindications.

Question 3750

Topic: 7. Hand and Wrist

What is the most likely long-term complication if a lunate dislocation is missed or inadequately treated?

. Carpal tunnel syndrome
. De Quervain's tenosynovitis
. Scapholunate advanced collapse (SLAC wrist)
. Ulnar nerve neuropathy
. Flexor carpi ulnaris tendinopathy

Correct Answer & Explanation

. Scapholunate advanced collapse (SLAC wrist)

Explanation

SLAC wrist (Scapholunate Advanced Collapse) is the most likely and debilitating long-term complication of missed or inadequately treated lunate or perilunate dislocations, particularly those involving scapholunate ligament injury. The chronic instability leads to abnormal mechanics and progressive degenerative arthritis. While carpal tunnel syndrome can be an acute complication, SLAC wrist describes the chronic arthritic degeneration. Other options are less directly linked as a primary long-term complication of a missed lunate dislocation.

Question 3751

Topic: 7. Hand and Wrist

During open reduction of a lunate dislocation, which carpal bone is typically reduced first to help re-establish carpal alignment?

. Scaphoid
. Triquetrum
. Lunate
. Trapezium
. Hamate

Correct Answer & Explanation

. Lunate

Explanation

When performing open reduction of a lunate dislocation, the lunate itself is usually reduced first. The goal is to bring the lunate back into its anatomical position within the lunate fossa of the radius. Once the lunate is reduced and provisionally stabilized (often with K-wires), the rest of the carpus (especially the capitate and scaphoid) can then be reduced around it, restoring the crucial radiolunate and capitolunate articulations. Attempting to reduce other bones first without the lunate in place is generally less effective.

Question 3752

Topic: Wrist & Carpus

A 28-year-old male sustains a dorsal perilunate dislocation. After successful closed reduction, what is the next most critical step in management to ensure optimal outcome and prevent recurrence?

. Immediate full range of motion exercises
. Application of a short arm cast for 2 weeks
. Referral for occupational therapy for desensitization
. Surgical stabilization with K-wires and ligament repair (ORIF)
. Prescription of NSAIDs and activity modification

Correct Answer & Explanation

. Surgical stabilization with K-wires and ligament repair (ORIF)

Explanation

Dorsal perilunate dislocations, even if successfully reduced closed, are highly unstable due to extensive ligamentous disruption. The next critical step is almost always surgical stabilization with K-wires and ligament repair (ORIF) to maintain the reduction and allow for proper ligamentous healing. Without surgical stabilization, the risk of redislocation and chronic instability (leading to SLAC wrist) is very high. Immediate motion is contraindicated. A short arm cast alone is insufficient for stabilization of such an unstable injury.

Question 3753

Topic: Wrist & Carpus

Which type of carpal instability is characterized by a volar tilt of the lunate on a lateral radiograph and is typically associated with a lunotriquetral ligament injury?

. DISI (Dorsal Intercalated Segmental Instability)
. VISI (Volar Intercalated Segmental Instability)
. SNAC (Scaphoid Nonunion Advanced Collapse)
. SLAC (Scapholunate Advanced Collapse)
. Radial intercalated segmental instability

Correct Answer & Explanation

. VISI (Volar Intercalated Segmental Instability)

Explanation

VISI (Volar Intercalated Segmental Instability) is characterized by a volar tilt or flexion of the lunate on a lateral radiograph. This pattern is typically associated with disruption of the lunotriquetral interosseous ligament (LTIL). DISI is a dorsal tilt of the lunate, associated with SLIL injury. SNAC and SLAC are patterns of degenerative arthritis. Radial intercalated segmental instability is not a recognized term.

Question 3754

Topic: Wrist & Carpus

What anatomical structure provides the most substantial extrinsic volar support to the lunate, often injured in lunate dislocations?

. Dorsal radiocarpal ligament
. Radioscaphocapitate ligament
. Ulnolunate ligament
. Triangular fibrocartilage complex (TFCC)
. Extensor carpi ulnaris tendon

Correct Answer & Explanation

. Radioscaphocapitate ligament

Explanation

The radioscaphocapitate ligament (also known as the 'long radiolunate ligament' or 'arcuate ligament') is a strong extrinsic volar ligament that originates from the radius and inserts onto the scaphoid, capitate, and lunate. It is a critical stabilizer of the scaphoid and lunate and is frequently torn in perilunate and lunate dislocations. The dorsal radiocarpal ligament is dorsal. The ulnolunate ligament is on the ulnar side. The TFCC stabilizes the DRUJ and ulnar carpus. The ECU tendon is an extrinsic muscle tendon.

Question 3755

Topic: 7. Hand and Wrist
A patient presents with persistent wrist pain and weakness 6 months after a successful closed reduction of a lunate dislocation. Clinical examination reveals mild tenderness over the dorsal wrist and a positive Watson (scaphoid shift) test. Radiographs show a persistently widened scapholunate interval. What is the most likely diagnosis?
. Kienböck's disease
. De Quervain's tenosynovitis
. Chronic scapholunate dissociation with instability
. Distal radioulnar joint (DRUJ) instability
. Ganglion cyst

Correct Answer & Explanation

. Chronic scapholunate dissociation with instability

Explanation

A persistently widened scapholunate interval on radiographs and a positive Watson test are pathognomonic for chronic scapholunate dissociation and instability, often a sequela of an inadequately healed perilunate injury or a missed ligamentous injury after reduction. While Kienböck's is avascular necrosis of the lunate, and De Quervain's is tenosynovitis, they do not present with these specific radiographic and clinical signs. DRUJ instability would involve ulnar-sided pain and specific DRUJ tests. A ganglion cyst is a soft tissue mass.

Question 3756

Topic: 7. Hand and Wrist
When assessing carpal alignment on an AP radiograph, what normal 'arc' should be present, and its disruption indicates carpal instability?
. The arc of the distal radius articular surface
. The arc of the metacarpal bases
. Gilula's three arcs
. The arc of the distal carpal row articulating with the metacarpals
. The arc of the ulnar head

Correct Answer & Explanation

. Gilula's three arcs

Explanation

Gilula's three arcs are three smooth, continuous lines that should be present on a normal AP radiograph of the wrist. Arc I outlines the proximal convexities of the scaphoid, lunate, and triquetrum. Arc II outlines the distal concavities of the same bones. Arc III outlines the proximal convexities of the capitate and hamate. Disruption of any of these arcs indicates carpal malalignment or instability. The other options are not specific to assessing intercarpal alignment in this manner.

Question 3757

Topic: Wrist & Carpus

Which surgical technique for lunate or perilunate dislocation repair involves advancing a portion of the dorsal radiocarpal ligament to augment the repair of the scapholunate ligament?

. Rappaport procedure
. Brunelli procedure
. Blatt capsulodesis (dorsal capsulodesis)
. Ramon's tenodesis
. Watson scaphoidectomy

Correct Answer & Explanation

. Blatt capsulodesis (dorsal capsulodesis)

Explanation

The Blatt capsulodesis, also known as dorsal capsulodesis, is a surgical technique used to stabilize the scapholunate joint, often in chronic scapholunate dissociation following perilunate injuries. It involves creating a flap from the dorsal radiocarpal ligament and attaching it to the dorsal aspect of the scaphoid and lunate to restrict excessive scaphoid flexion. The Brunelli procedure uses a flexor carpi radialis (FCR) slip. Rappaport and Ramon's tenodesis are not standard terms for this approach. Watson scaphoidectomy is part of a SLAC wrist salvage.

Question 3758

Topic: Wrist & Carpus

What is the critical differentiating factor between a dorsal perilunate dislocation and a dorsal trans-scaphoid perilunate dislocation?

. The direction of lunate displacement
. The involvement of median nerve compression
. The presence of an associated scaphoid fracture
. The degree of soft tissue swelling
. The patient's age and activity level

Correct Answer & Explanation

. The presence of an associated scaphoid fracture

Explanation

The critical differentiating factor is the presence of an associated scaphoid fracture. In a dorsal perilunate dislocation, the entire carpus (excluding the lunate) displaces dorsally, and the scapholunate ligament typically ruptures. In a dorsal trans-scaphoid perilunate dislocation, the scaphoid fractures instead of the scapholunate ligament tearing, and the fracture fragments displace along with the rest of the carpus. This has significant implications for surgical management.

Question 3759

Topic: 7. Hand and Wrist

In the context of carpal injury imaging, what specific view is often most helpful in demonstrating a subtle scapholunate dissociation?

. AP view with wrist in ulnar deviation
. Lateral view with wrist in neutral position
. Scaphoid view (AP oblique with ulnar deviation)
. Clenched-fist AP view
. AP view with wrist in radial deviation

Correct Answer & Explanation

. Clenched-fist AP view

Explanation

A clenched-fist AP view (or radial deviation view) is often crucial for unmasking a subtle scapholunate dissociation. By making a fist, the extensor carpi radialis longus and brevis contract, pulling the scaphoid proximally and radially. If the scapholunate ligament is torn, this maneuver can exaggerate the scapholunate gap ('Terry Thomas sign') and reveal dynamic instability that might not be visible on standard views. The scaphoid view is good for scaphoid fractures. Ulnar deviation may close the gap.

Question 3760

Topic: 7. Hand and Wrist

What is the typical presentation of a patient with an untreated chronic lunate dislocation after several months or years?

. Acute, severe, throbbing pain requiring immediate surgical intervention
. Spontaneous resolution of symptoms with minimal long-term sequelae
. Progressive wrist pain, stiffness, weakness, and eventual degenerative arthritis
. Localized pain at the distal radioulnar joint (DRUJ)
. Isolated numbness in the ulnar nerve distribution

Correct Answer & Explanation

. Progressive wrist pain, stiffness, weakness, and eventual degenerative arthritis

Explanation

Untreated chronic lunate dislocations inevitably lead to progressive wrist pain, stiffness, weakness, and the development of degenerative arthritis (SLAC wrist). The chronic malalignment causes abnormal loading patterns and articular cartilage damage. Acute, severe pain usually subsides after the acute phase, but chronic, escalating pain replaces it. Spontaneous resolution is highly unlikely. DRUJ pain and ulnar nerve symptoms are not the primary, most common long-term sequelae of a lunate dislocation.

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