Menu

Wrist & Carpus MCQs

Practice Set 26 of 33

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

Question 501

Topic: Wrist & Carpus

In an effort to prevent the development of Complex Regional Pain Syndrome (CRPS) following a conservatively managed distal radius fracture, the American Academy of Orthopaedic Surgeons (AAOS) recommends which of the following oral prophylactic therapies?

. Gabapentin 300 mg daily for 21 days
. Vitamin C 500 mg daily for 50 days
. Ibuprofen 400 mg every 8 hours for 14 days
. Prednisone taper over 10 days
. Amitriptyline 25 mg nightly for 30 days

Correct Answer & Explanation

. Gabapentin 300 mg daily for 21 days

Explanation

The daily administration of 500 mg of Vitamin C for 50 days following a distal radius fracture has been shown to significantly reduce the risk of developing CRPS, primarily through its antioxidant and free radical scavenging properties.

Question 502

Topic: Wrist & Carpus

When evaluating a clinically suspected occult scaphoid fracture with negative plain radiographs, which of the following MRI sequences is most sensitive for detecting the early bone marrow edema associated with the injury?

. T1-weighted spin echo
. T2-weighted spin echo
. Short tau inversion recovery (STIR)
. Gradient echo (GRE)
. Proton density without fat saturation

Correct Answer & Explanation

. T1-weighted spin echo

Explanation

STIR sequences suppress fat signal and are highly sensitive for detecting increased water content. This makes them excellent for identifying early bone marrow edema associated with occult fractures, stress responses, or early avascular necrosis.

Question 503

Topic: Wrist & Carpus

The triangular fibrocartilage complex (TFCC) is the major stabilizer of the distal radioulnar joint (DRUJ). Which specific part of the TFCC has a rich blood supply and is therefore more amenable to primary surgical repair?

. The central articular disc
. The radial attachment
. The peripheral (ulnar) aspect
. The deep foveal attachment exclusively
. The midsubstance of the palmar radioulnar ligament

Correct Answer & Explanation

. The central articular disc

Explanation

The blood supply to the TFCC is limited to its peripheral 10-20%, which receives vessels from the ulnar artery and the palmar/dorsal branches of the anterior interosseous artery. The central and radial portions are avascular. Therefore, peripheral (ulnar-sided) tears have healing potential and are often amenable to primary repair.

Question 504

Topic: Wrist & Carpus

A 32-year-old male sustains a Galeazzi fracture-dislocation. Intraoperatively, after achieving anatomic open reduction and rigid internal fixation of the radial shaft with a compression plate, the distal radioulnar joint (DRUJ) remains unstable in both supination and pronation. What is the most appropriate next step in management?

. Pinning the DRUJ with Kirschner wires in neutral rotation
. Pinning the DRUJ with Kirschner wires in maximum supination
. Pinning the DRUJ with Kirschner wires in maximum pronation
. Immediate open repair of the triangular fibrocartilage complex (TFCC) from a dorsal approach
. Application of an external fixator across the wrist joint

Correct Answer & Explanation

. Pinning the DRUJ with Kirschner wires in neutral rotation

Explanation

A Galeazzi injury involves a fracture of the distal third of the radial shaft with associated disruption of the DRUJ. The initial step is stable anatomic fixation of the radius. If the DRUJ remains unstable, it should be assessed in different forearm rotations. Supination tension the palmar radioulnar ligament and often reduces the DRUJ. If it is unstable, the DRUJ should be reduced and pinned with K-wires in supination for 4 to 6 weeks. Primary open repair of the TFCC is generally reserved for irreducibility of the DRUJ (e.g., due to interposed extensor carpi ulnaris tendon).

Question 505

Topic: Wrist & Carpus

A 65-year-old female presents with a volar shear fracture of the distal radius (volar Barton fracture). Which of the following is the most appropriate surgical approach and internal fixation method?

. Dorsal approach with a dorsal spanning plate
. Volar approach with a volar buttress plate
. Volar approach with a dorsal tension band
. Dorsal approach with percutaneous pinning
. Mini-open approach with a Herbert screw

Correct Answer & Explanation

. Dorsal approach with a dorsal spanning plate

Explanation

A volar Barton fracture is an unstable intra-articular shear fracture of the distal radius. It cannot be adequately held by cast immobilization due to shear forces. The standard of care is a volar approach and fixation with a volar buttress plate (or volar locking plate applied in a buttress mode) to counteract the palmar subluxation of the carpus.

Question 506

Topic: Wrist & Carpus

A 55-year-old female undergoes volar locking plate fixation for a displaced intra-articular distal radius fracture. Six months postoperatively, she returns complaining of a sudden inability to actively flex the interphalangeal joint of her thumb. This complication is most closely associated with which of the following surgical technique errors?

. Placement of the volar plate distal to the watershed line
. Placement of the volar plate proximal to the pronator quadratus
. Intra-articular screw penetration of the radiocarpal joint
. Dorsal screw protrusion past the dorsal cortex
. Inadequate restoration of radial inclination

Correct Answer & Explanation

. Placement of the volar plate distal to the watershed line

Explanation

The inability to actively flex the thumb IP joint indicates a rupture of the flexor pollicis longus (FPL) tendon. In the setting of a prior volar plate for a distal radius fracture, FPL rupture is a known complication associated with plate prominence. When the plate is placed distal to the 'watershed line' (a transverse ridge on the volar distal radius), the prominent distal edge of the hardware causes mechanical attrition and eventual rupture of the FPL tendon.

Question 507

Topic: Wrist & Carpus

During a fluoroscopically assisted closed reduction of a distal radius fracture, the surgeon initially stands 1 meter away from the C-arm beam. If the surgeon steps back to a distance of 2 meters, the radiation exposure is altered by what factor according to the inverse square law?

. Reduced to 1/2 of the original exposure
. Reduced to 1/4 of the original exposure
. Reduced to 1/8 of the original exposure
. Reduced to 1/16 of the original exposure
. Remains unchanged due to scatter radiation

Correct Answer & Explanation

. Reduced to 1/2 of the original exposure

Explanation

The inverse square law states that the intensity of radiation is inversely proportional to the square of the distance from the source (Intensity = 1/d^2). Doubling the distance (from 1 meter to 2 meters) reduces the radiation exposure to 1/2^2, which is 1/4 of the original exposure.

Question 508

Topic: Wrist & Carpus

A 45-year-old patient receives an axillary block using 0.5% bupivacaine for a distal radius fracture repair. Thirty minutes later, she develops perioral numbness, visual disturbances, muscle twitching, and subsequently progresses to ventricular fibrillation. What is the most appropriate initial specific antidote to administer?

. Intravenous dantrolene
. Intravenous calcium chloride
. Intravenous 20% lipid emulsion
. Intravenous flumazenil
. Intravenous physostigmine

Correct Answer & Explanation

. Intravenous dantrolene

Explanation

The patient is experiencing Local Anesthetic Systemic Toxicity (LAST), progressing from early CNS symptoms to catastrophic cardiovascular collapse. Bupivacaine is highly cardiotoxic. The first-line specific treatment for LAST is the administration of a 20% intravenous lipid emulsion, which acts as a 'lipid sink' to draw the highly lipophilic local anesthetic out of the myocardium and CNS tissues.

Question 509

Topic: Wrist & Carpus

A 40-year-old female presents with ulnar-sided wrist pain that worsens with pronation and gripping. Radiographs demonstrate a positive ulnar variance of +4 mm and cystic changes in the lunate and triquetrum. MRI confirms a central perforation of the TFCC but an intact distal radioulnar joint (DRUJ) cartilage. What is the most appropriate surgical intervention?

. Darrach procedure
. Suave-Kapandji procedure
. Ulnar shortening osteotomy
. Proximal row carpectomy
. Wafer procedure (distal ulnar resection)

Correct Answer & Explanation

. Darrach procedure

Explanation

This is a classic presentation of Ulnar Impaction Syndrome. With a positive ulnar variance of +4 mm and preserved DRUJ articular cartilage, an ulnar shortening osteotomy (extra-articular) is the gold standard. It unloads the ulnocarpal joint while tightening the ulnocarpal ligaments. A Wafer procedure is generally reserved for variance of +2 mm or less. Darrach and Suave-Kapandji are salvage procedures for DRUJ arthritis.

Question 510

Topic: Wrist & Carpus

Six weeks following a non-displaced distal radius fracture treated successfully with a short arm cast, a 58-year-old female presents with a sudden inability to actively lift her thumb into extension. Which tendon is the standard choice for transfer to restore this lost function?

. Extensor indicis proprius (EIP)
. Extensor carpi radialis longus (ECRL)
. Palmaris longus (PL)
. Flexor digitorum superficialis (FDS) of the ring finger
. Abductor pollicis longus (APL)

Correct Answer & Explanation

. Extensor indicis proprius (EIP)

Explanation

The patient has experienced an attritional rupture of the Extensor Pollicis Longus (EPL) tendon, a well-known complication of non-displaced distal radius fractures (due to ischemia or mechanical wear at Lister's tubercle). The Extensor Indicis Proprius (EIP) transfer is the gold standard procedure to restore independent thumb extension.

Question 511

Topic: Wrist & Carpus

A 60-year-old female presents with sudden inability to flex the interphalangeal (IP) joint of her right thumb. She underwent open reduction and internal fixation of a distal radius fracture with a volar locking plate 6 months ago. What is the most likely surgical error that led to this complication?

. Penetration of screws into the distal radioulnar joint
. Over-contouring of the plate against the radial styloid
. Placement of the volar plate distal to the watershed line
. Failure to repair the pronator quadratus during closure
. Placing screws too dorsally through the second extensor compartment

Correct Answer & Explanation

. Penetration of screws into the distal radioulnar joint

Explanation

Spontaneous rupture of the Flexor Pollicis Longus (FPL) tendon is a known complication of volar plating of the distal radius. This almost invariably occurs when the plate is positioned too far distally, specifically prominent volar to the watershed line of the distal radius. The watershed line is a theoretical margin marking the most distal edge of the flat volar surface of the radius before the articular surface slopes dorsally. Implants placed distal to this line directly irritate the FPL tendon, leading to attrition and eventually rupture.

Question 512

Topic: Wrist & Carpus
A 45-year-old manual laborer presents with chronic right wrist pain. He has a history of a neglected scaphoid fracture 10 years ago. Radiographs reveal advanced radiocarpal arthritis and capitolunate arthritis. The radiolunate joint is remarkably preserved. Which of the following is the most appropriate surgical intervention?
. Proximal row carpectomy (PRC)
. Scaphoid excision and four-corner fusion
. Radial styloidectomy alone
. Total wrist arthroplasty
. Radioscapholunate (RSL) fusion

Correct Answer & Explanation

. Scaphoid excision and four-corner fusion

Explanation

The patient has Scaphoid Nonunion Advanced Collapse (SNAC) Stage III, characterized by radioscaphoid and capitolunate arthritis, but with sparing of the 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). The procedure of choice in an active laborer with SNAC III is scaphoid excision and four-corner fusion (capitate, hamate, lunate, triquetrum), preserving the functional radiolunate joint.

Question 513

Topic: Wrist & Carpus

In Scapholunate Advanced Collapse (SLAC) of the wrist, a predictable and sequential pattern of articular degeneration occurs. Despite severe arthritis at the radioscaphoid and capitolunate joints, the radiolunate joint is almost universally spared. What anatomical and biomechanical characteristic of the radiolunate joint explains this sparing?

. The lunate has no direct ligamentous attachments to the radius.
. The lunate articular surface is entirely covered by the TFCC.
. The radiolunate articulation is perfectly spherical and concentric.
. The radiolunate joint is elliptical, preventing rotation.
. The lunate relies exclusively on the radioscaphocapitate ligament for stability.

Correct Answer & Explanation

. The lunate has no direct ligamentous attachments to the radius.

Explanation

In SLAC wrist, the radiolunate joint is famously spared from osteoarthritis. This is because the articulation between the lunate and the lunate fossa of the distal radius is spherical and concentric. Even when the lunate rotates dorsally (DISI deformity) due to scapholunate ligament incompetence, the spherical geometry maintains a congruent joint surface with evenly distributed loads. In contrast, the radioscaphoid joint is elliptical; when the scaphoid flexes, point loading occurs, leading to rapid cartilage breakdown.

Question 514

Topic: Wrist & Carpus

A 32-year-old gymnast presents with severe ulnar-sided wrist pain after a fall. An MRI confirms a Palmer Class 1B tear of the Triangular Fibrocartilage Complex (TFCC).

Which of the following best describes this specific injury pattern?

. Central articular disc perforation
. Ulnar avulsion with or without an ulnar styloid fracture
. Distal avulsion involving the ulnocarpal ligaments
. Radial avulsion of the TFCC from the sigmoid notch
. Degenerative tear with ulnocarpal impaction syndrome

Correct Answer & Explanation

. Central articular disc perforation

Explanation

The Palmer classification divides TFCC tears into traumatic (Class 1) and degenerative (Class 2). Class 1B refers to an ulnar avulsion (from the fovea/base of the ulnar styloid), which is well-vascularized and highly amenable to primary surgical repair. Class 1A is central (avascular, treated with debridement); Class 1C is distal (ulnocarpal ligaments); Class 1D is a radial avulsion.

Question 515

Topic: Wrist & Carpus
A 40-year-old man presents with chronic wrist pain. Radiographs demonstrate a scaphoid nonunion with arthritic changes involving the entire scaphoid fossa of the radius, but the capitolunate joint and radiolunate joint are preserved. What is the stage of Scaphoid Nonunion Advanced Collapse (SNAC) and the most appropriate surgical treatment?
. Stage I SNAC; Radial styloidectomy and scaphoid fixation
. Stage II SNAC; Proximal row carpectomy or four-corner fusion
. Stage III SNAC; Total wrist arthrodesis
. Stage I SNAC; Four-corner fusion
. Stage II SNAC; Total wrist arthroplasty

Correct Answer & Explanation

. Stage II SNAC; Proximal row carpectomy or four-corner fusion

Explanation

SNAC Stage II involves radioscaphoid arthritis extending beyond the radial styloid to include the entire scaphoid fossa. The radiolunate and midcarpal joints are spared. Acceptable surgical treatments for Stage II include proximal row carpectomy (PRC) or scaphoid excision with four-corner arthrodesis.

Question 516

Topic: Wrist & Carpus
A 50-year-old man presents with chronic radial-sided wrist pain. Radiographs reveal scapholunate dissociation with advanced arthritic changes involving the radioscaphoid joint and the capitolunate joint, but the radiolunate joint is spared. What is the appropriate SLAC stage and recommended surgical treatment?
. Stage I SLAC; Radial styloidectomy
. Stage II SLAC; Proximal row carpectomy
. Stage III SLAC; Four-corner arthrodesis
. Stage IV SLAC; Total wrist arthrodesis
. Stage II SLAC; Scaphocapitate fusion

Correct Answer & Explanation

. Stage III SLAC; Four-corner arthrodesis

Explanation

This is Stage III SLAC (Scapholunate Advanced Collapse), characterized by progressive arthritis involving the radioscaphoid and capitolunate joints, while the radiolunate joint is uniquely spared. Four-corner arthrodesis (with scaphoid excision) is the standard treatment. Proximal row carpectomy is contraindicated due to capitate head arthritis.

Question 517

Topic: Wrist & Carpus

A 65-year-old female presents 6 weeks after non-operative management of a nondisplaced distal radius fracture. She reports suddenly losing the ability to actively extend her thumb interphalangeal joint. Which tendon transfer is considered the gold standard for restoring this function?

. Flexor Carpi Radialis (FCR) to Extensor Pollicis Longus (EPL)
. Extensor Indicis Proprius (EIP) to Extensor Pollicis Longus (EPL)
. Palmaris Longus (PL) to Extensor Pollicis Longus (EPL)
. Extensor Carpi Radialis Longus (ECRL) to Extensor Pollicis Longus (EPL)
. Abductor Pollicis Longus (APL) to Extensor Pollicis Longus (EPL)

Correct Answer & Explanation

. Flexor Carpi Radialis (FCR) to Extensor Pollicis Longus (EPL)

Explanation

Extensor pollicis longus (EPL) rupture is a known complication of nondisplaced distal radius fractures due to ischemia or attrition at Lister's tubercle. The Extensor Indicis Proprius (EIP) to EPL transfer is the preferred reconstruction because it matches the excursion and vector of the EPL.

Question 518

Topic: Wrist & Carpus

A 55-year-old woman underwent volar locking plate fixation for a distal radius fracture 6 months ago. She now presents with an inability to actively flex the interphalangeal joint of her thumb. She reports a sudden pop without significant trauma. What is the most likely cause?

. Non-union of the distal radius
. Attritional rupture of the flexor pollicis longus (FPL) tendon
. Anterior interosseous nerve (AIN) palsy
. Extensor pollicis longus (EPL) rupture
. Trigger thumb

Correct Answer & Explanation

. Non-union of the distal radius

Explanation

Attritional rupture of the flexor pollicis longus (FPL) tendon is a recognized complication of volar plating of the distal radius. It typically occurs due to prominent hardware (especially the distal edge of the plate) irritating the tendon as it crosses the watershed line. Patients present with loss of active IP joint flexion of the thumb. A sudden 'pop' is characteristic of the tendon rupturing.

Question 519

Topic: Wrist & Carpus

A 65-year-old female presents with wrist pain after a fall. Radiographs reveal a volar Barton's fracture of the distal radius. Which of the following describes the pathognomonic feature of this fracture pattern?

. Extra-articular fracture with dorsal angulation of the distal fragment
. Intra-articular fracture characterized by volar subluxation of the carpus with the volar articular fragment
. Isolated fracture of the radial styloid
. Metaphyseal comminution with extension into the distal radioulnar joint (DRUJ) without radiocarpal involvement
. Fracture-dislocation of the radiocarpal joint with intact volar ligaments and a dorsal shear fragment

Correct Answer & Explanation

. Extra-articular fracture with dorsal angulation of the distal fragment

Explanation

A volar Barton's fracture is a shear fracture of the volar lip of the distal radius articular surface. Its pathognomonic feature is that the carpus remains articulated with the fractured volar fragment and subluxates or dislocates volarly along with it. It typically requires open reduction and internal fixation with a volar buttress plate.

Question 520

Topic: Wrist & Carpus

Madelung deformity results from a localized growth disturbance of the volar-ulnar aspect of the distal radius physis. This condition is characterized by a tethering anomalous ligament known as:

. Ligament of Testut
. Vickers ligament
. Osborne's ligament
. Struthers ligament
. Bouvier's ligament

Correct Answer & Explanation

. Ligament of Testut

Explanation

Vickers ligament is an anomalous, thickened volar radiolunate ligament that tethers the volar-ulnar aspect of the distal radius. This tethering restricts normal physeal growth in that region, leading to the characteristic volar and ulnar tilt of the distal radius articular surface seen in Madelung deformity.

Test Yourself

Switch to an interactive, timed exam simulation to truly master this topic.

On this Page