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Wrist & Carpus MCQs

Practice Set 30 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 581

Topic: Wrist & Carpus
A 25-year-old elite tennis player complains of chronic, ulnar-sided wrist pain and clicking, notably during forearm pronation. Physical exam reveals a positive fovea sign and palpable instability of the distal radioulnar joint (DRUJ). MRI arthrogram demonstrates a Palmer Class 1B tear of the Triangular Fibrocartilage Complex (TFCC). Following a failed 3-month course of conservative management, what is the most appropriate surgical intervention?
. Ulnar shortening osteotomy
. Darrach procedure
. Arthroscopic or open repair of the TFCC to the ulnar fovea
. Sauvé-Kapandji procedure
. Arthroscopic central debridement of the TFCC (wafer procedure)

Correct Answer & Explanation

. Arthroscopic or open repair of the TFCC to the ulnar fovea

Explanation

A Palmer Class 1B tear is an acute, traumatic avulsion of the TFCC from its ulnar attachment (the fovea and/or base of the ulnar styloid). Because this peripheral region of the TFCC is highly vascularized (unlike the avascular central portion, which is Palmer 1A), it possesses excellent healing potential. When associated with DRUJ instability and refractory to conservative treatment, the gold standard is anatomic repair (arthroscopic or open) of the TFCC back to the ulnar fovea. Ulnar shortening is indicated for ulnar impaction syndrome, and salvage procedures (Darrach/Sauvé-Kapandji) are for end-stage DRUJ arthritis.

Question 582

Topic: Wrist & Carpus

During surgical reduction of a Galeazzi fracture (distal radius shaft fracture with distal radioulnar joint (DRUJ) dislocation), the DRUJ remains irreducible despite anatomic fixation of the radius. Which anatomical structure is the most common cause of an irreducible DRUJ block in this scenario?

. Flexor carpi radialis tendon
. Extensor carpi ulnaris (ECU) tendon
. Pronator quadratus muscle belly
. Superficial branch of the radial nerve
. Triangular fibrocartilage complex (TFCC) central articular disc

Correct Answer & Explanation

. Extensor carpi ulnaris (ECU) tendon

Explanation

In a Galeazzi fracture-dislocation, if the DRUJ cannot be reduced after the radius is fixed, the most common soft-tissue block is the interposition of the Extensor Carpi Ulnaris (ECU) tendon into the DRUJ, necessitating open reduction to extract the tendon.

Question 583

Topic: Wrist & Carpus

A 60-year-old woman with a 20-year history of rheumatoid arthritis presents with a sudden inability to flex the interphalangeal joint of her thumb. She denies acute trauma. This presentation (Mannerfelt syndrome) is most classically caused by attrition of the flexor pollicis longus (FPL) tendon over which bony prominence?

. Lister's tubercle
. Volar osteophyte of the scaphoid
. Hook of the hamate
. Volar lip of the distal radius
. Trapezium

Correct Answer & Explanation

. Volar osteophyte of the scaphoid

Explanation

Mannerfelt syndrome in rheumatoid arthritis refers to the spontaneous rupture of the flexor pollicis longus (FPL) tendon. It is most commonly caused by attrition of the tendon as it glides over a sharp, volar osteophyte originating from the scaphoid (often at the STT joint).

Question 584

Topic: Wrist & Carpus

A 55-year-old female with long-standing rheumatoid arthritis suddenly loses the ability to actively flex the interphalangeal joint of her thumb. This attritional tendon rupture (Mannerfelt syndrome) most commonly occurs secondary to friction over which bony structure?

. Lister's tubercle
. Volar aspect of the scaphoid
. Dorsal aspect of the distal radius
. Pisiform
. Hook of the hamate

Correct Answer & Explanation

. Volar aspect of the scaphoid

Explanation

Mannerfelt syndrome refers to the attritional rupture of the flexor pollicis longus (FPL) tendon. It classically occurs due to friction over a prominent volar scaphoid osteophyte penetrating the capsule in rheumatoid arthritis.

Question 585

Topic: Wrist & Carpus

Which Palmer classification of triangular fibrocartilage complex (TFCC) tears has the best potential for healing with direct surgical repair due to its regional vascularity?

. Palmer 1A (Central perforation)
. Palmer 1B (Ulnar avulsion)
. Palmer 1C (Distal avulsion)
. Palmer 1D (Radial avulsion)
. Palmer 2C (Degenerative perforation)

Correct Answer & Explanation

. Palmer 1B (Ulnar avulsion)

Explanation

Palmer 1B tears involve an avulsion of the TFCC from the distal ulna. The ulnar periphery of the TFCC is well-vascularized (the 'red zone'), providing excellent healing potential following direct capsular or osseous repair.

Question 586

Topic: Wrist & Carpus

A 50-year-old man presents with advanced Scapholunate Advanced Collapse (SLAC) wrist. When considering a Proximal Row Carpectomy (PRC) as a surgical option, which of the following radiographic findings serves as an absolute contraindication to this procedure?

. A scapholunate angle greater than 70 degrees
. Advanced radioscaphoid osteoarthritis
. Advanced capitolunate osteoarthritis
. Ulnar positive variance of 2 mm
. Lunate type I morphology

Correct Answer & Explanation

. Advanced capitolunate osteoarthritis

Explanation

Proximal Row Carpectomy (PRC) relies on a preserved articulation between the head of the capitate and the lunate fossa of the distal radius. Therefore, significant osteoarthritis of the capitolunate joint or the capitate head is a contraindication.

Question 587

Topic: Wrist & Carpus

Following open reduction and internal fixation of a distal radius fracture with a volar locking plate, the patient develops a delayed rupture of the flexor pollicis longus (FPL) tendon. The surgeon placed the plate distal to a critical anatomical landmark, leading to tendon attrition. What is this landmark?

. Lister's tubercle
. The watershed line
. The sigmoid notch
. The volar radioulnar ligament
. The pronator quadratus fossa

Correct Answer & Explanation

. The watershed line

Explanation

The 'watershed line' is a distinct anatomical ridge on the volar surface of the distal radius. It marks the most volar projection of the distal radius. Volar plates placed distal to the watershed line are prominent relative to the flexor tendons, creating a high risk for attritional rupture, particularly of the flexor pollicis longus (FPL) tendon.

Question 588

Topic: Wrist & Carpus

A 62-year-old female with long-standing rheumatoid arthritis presents with an inability to actively extend her ring and small fingers at the metacarpophalangeal joints. She can still extend her index and middle fingers. The tenodesis effect is absent in the affected digits. What is the most appropriate management?

. Sagittal band reconstruction
. Extensor indicis proprius (EIP) transfer to the affected digits
. Side-to-side transfer of the affected extensor tendons to the intact extensor digitorum communis of the middle finger
. Distal radioulnar joint (DRUJ) arthroplasty
. Extensor carpi radialis longus (ECRL) transfer

Correct Answer & Explanation

. Side-to-side transfer of the affected extensor tendons to the intact extensor digitorum communis of the middle finger

Explanation

This patient has Vaughan-Jackson syndrome, characterized by sequential rupture of the extensor tendons from the ulnar to the radial side due to attrition over a prominent distal ulna (caput ulnae). Treatment involves removing the prominent ulnar head (e.g., Darrach or Suave-Kapandji) and transferring the ruptured EDQ and EDC of the ring/small fingers side-to-side to the intact EDC of the middle finger.

Question 589

Topic: Wrist & Carpus

The Palmer classification is used for Triangular Fibrocartilage Complex (TFCC) lesions. A traumatic avulsion of the TFCC from its distal attachment at the lunate or triquetrum is classified as:

. Class 1A
. Class 1B
. Class 1C
. Class 1D
. Class 2C

Correct Answer & Explanation

. Class 1B

Explanation

Palmer classification of traumatic (Class 1) TFCC tears: 1A = central perforation; 1B = ulnar avulsion (with or without an ulnar styloid fracture); 1C = distal avulsion (from the carpus - lunate/triquetrum via ulnotriquetral/ulnolunate ligaments); 1D = radial avulsion (from the sigmoid notch). Class 2 represents degenerative tears.

Question 590

Topic: Wrist & Carpus

A 45-year-old carpenter complains of progressive wrist pain over the ulnar aspect. Radiographs show positive ulnar variance with subchondral cystic changes in the lunate and ulnar head. MRI demonstrates a central tear of the triangular fibrocartilage complex (TFCC). Following a failed 6-month trial of conservative management, what is the most appropriate surgical intervention?

. Arthroscopic TFCC repair to the fovea
. Arthroscopic wafer procedure
. Ulnar shortening osteotomy
. Darrach procedure
. Bowers hemiresection interposition arthroplasty

Correct Answer & Explanation

. Ulnar shortening osteotomy

Explanation

The patient has ulnar impaction syndrome with positive ulnar variance. An ulnar shortening osteotomy is the most appropriate surgical treatment for a patient with positive ulnar variance and an intact DRUJ, as it directly addresses the mechanical overload while tightening the ulnocarpal ligaments. An arthroscopic wafer procedure is generally reserved for patients with neutral or slightly positive variance (less than 2-3 mm) or when avoiding osteotomy hardware is desired, but shortening osteotomy remains the gold standard for distinct positive variance.

Question 591

Topic: Wrist & Carpus

A 19-year-old gymnast presents with persistent ulnar-sided wrist pain exacerbated by forearm rotation. MRI confirms a Palmer Class 1B tear of the triangular fibrocartilage complex (TFCC). This specific tear pattern involves detachment from which structure?

. Radial sigmoid notch
. Lunate and triquetrum
. Ulnar fovea and base of ulnar styloid
. Volar ulnocarpal ligaments
. Extensor carpi ulnaris subsheath

Correct Answer & Explanation

. Ulnar fovea and base of ulnar styloid

Explanation

A Palmer Class 1B TFCC tear represents a traumatic avulsion of the TFCC from its peripheral ulnar attachment (fovea or base of the ulnar styloid). Since this peripheral area is well-vascularized, it has excellent healing potential following direct surgical repair.

Question 592

Topic: Wrist & Carpus

A 25-year-old male sustains a diaphyseal fracture of the radius with associated distal radioulnar joint (DRUJ) dislocation. Following anatomic open reduction and internal fixation of the radius, the DRUJ remains grossly unstable in full supination. What is the most appropriate next step in management?

. Immobilization in a long arm cast in full supination for 6 weeks
. Open exploration of the DRUJ with primary repair of the triangular fibrocartilage complex
. Percutaneous trans-articular pinning of the DRUJ in neutral rotation
. Resection of the distal ulna (Darrach procedure)
. Distal ulnar shortening osteotomy

Correct Answer & Explanation

. Open exploration of the DRUJ with primary repair of the triangular fibrocartilage complex

Explanation

If the DRUJ is irreducible or remains grossly unstable after anatomic radius fixation in a Galeazzi fracture, an open approach to the DRUJ is required. This instability is often due to soft tissue interposition (such as the ECU tendon or capsule) and requires direct TFCC repair.

Question 593

Topic: Wrist & Carpus

A patient treated with a volar locking plate for a distal radius fracture 3 months ago now presents with the inability to actively flex the interphalangeal joint of the thumb. Which of the following technical errors during the index surgery is the most likely cause of this complication?

. Prominent dorsal screw penetration into the extensor compartments
. Placement of the volar plate distal to the watershed line
. Inadequate reduction of the Lister tubercle
. Failure to release the brachioradialis insertion during the approach
. Use of excessively long peg screws in the distal row

Correct Answer & Explanation

. Placement of the volar plate distal to the watershed line

Explanation

Flexor pollicis longus (FPL) tendon rupture is a well-known complication of volar plating for distal radius fractures. It is classically caused by attrition/friction against a prominent plate placed too distally, crossing the 'watershed line' and impinging directly on the volar flexor tendons.

Question 594

Topic: Wrist & Carpus

A surgeon is performing a closed reduction of a distal radius fracture under a hematoma block. What is the generally accepted maximum safe dose of lidocaine without epinephrine for local infiltration in an adult patient?

. 2.0 mg/kg
. 4.5 mg/kg
. 7.0 mg/kg
. 10.0 mg/kg
. 15.0 mg/kg

Correct Answer & Explanation

. 4.5 mg/kg

Explanation

The maximum safe dose of 1% lidocaine without epinephrine for local infiltration is 4.5 mg/kg (up to approximately 300 mg total in an average adult). The addition of epinephrine increases the maximum safe dose to 7.0 mg/kg.

Question 595

Topic: Wrist & Carpus
A 55-year-old male presents with severe wrist pain and is diagnosed with Stage III Scapholunate Advanced Collapse (SLAC). The surgeon is debating between a proximal row carpectomy (PRC) and a four-corner fusion. Which of the following findings is an absolute contraindication to performing a proximal row carpectomy?
. A scapholunate interval greater than 3 mm
. Severe degeneration of the proximal capitate articular surface
. Radioscaphoid arthritis involving the radial styloid
. Ulnar positive variance
. An intact radioscaphocapitate ligament

Correct Answer & Explanation

. Severe degeneration of the proximal capitate articular surface

Explanation

Proximal row carpectomy (PRC) relies on a healthy articulation between the head of the capitate and the lunate fossa of the distal radius. Therefore, significant degenerative arthritis of the proximal capitate articular surface (capitolunate arthritis) is a strict contraindication to a PRC. In such cases, a four-corner fusion with scaphoid excision is the preferred motion-preserving alternative.

Question 596

Topic: Wrist & Carpus
A 32-year-old manual laborer presents with dorsal wrist pain. Radiographs reveal sclerosis of the lunate without collapse, and an ulnar variance of -3 mm. MRI confirms avascular necrosis of the lunate. Which of the following is the most appropriate initial surgical intervention?
. Proximal row carpectomy
. Scaphocapitate fusion
. Radial shortening osteotomy
. Ulnar lengthening osteotomy
. Vascularized bone graft from the distal radius without joint leveling

Correct Answer & Explanation

. Radial shortening osteotomy

Explanation

This patient has Stage II Kienböck's disease (sclerosis of the lunate, normal architecture without collapse) combined with negative ulnar variance. The standard of care to decompress the lunate in the setting of negative ulnar variance is a joint leveling procedure. Radial shortening osteotomy is biomechanically superior and has a lower complication rate compared to ulnar lengthening.

Question 597

Topic: Wrist & Carpus

A 45-year-old gymnast complains of chronic ulnar-sided wrist pain that worsens with pronation and ulnar deviation. Radiographs reveal ulnar positive variance and cystic changes in the lunate and triquetrum. MRI confirms tears of the central TFCC articular disc but demonstrates that the distal radioulnar joint (DRUJ) is perfectly congruent without arthritic changes. Which of the following surgical procedures is most appropriate?

. Ulnar shortening osteotomy
. Hemiresection interposition arthroplasty (Bowers procedure)
. Darrach procedure
. Ulnar head replacement
. Sauve-Kapandji procedure

Correct Answer & Explanation

. Ulnar shortening osteotomy

Explanation

Ulnar shortening osteotomy is the treatment of choice for ulnar impaction syndrome in patients with positive ulnar variance and a congruent, non-arthritic DRUJ. It effectively unloads the ulnocarpal joint and tightens the ulnocarpal ligaments. If significant DRUJ arthritis were present, a salvage procedure like a Sauve-Kapandji or Darrach procedure would be considered instead.

Question 598

Topic: Wrist & Carpus
A 50-year-old manual laborer presents with chronic progressive wrist pain years after an untreated scapholunate ligament tear. Radiographs reveal advanced arthritis involving the radioscaphoid joint and the capitolunate joint. The radiolunate joint is characteristically spared. What is the Watson stage of this patient's wrist, and what is the preferred salvage procedure?
. Stage II SLAC; treated with proximal row carpectomy
. Stage III SLAC; treated with scaphoid excision and four-corner fusion
. Stage III SLAC; treated with proximal row carpectomy
. Stage IV SLAC; treated with scaphoid excision and four-corner fusion
. Stage II SLAC; treated with total wrist arthrodesis

Correct Answer & Explanation

. Stage IV SLAC; treated with scaphoid excision and four-corner fusion

Explanation

Scapholunate advanced collapse (SLAC) Stage III involves arthritis of the radioscaphoid and capitolunate joints, while the radiolunate joint is spared. Because the capitate head is arthritic, a proximal row carpectomy (PRC) is contraindicated (as the arthritic capitate would articulate with the lunate fossa). Scaphoid excision and four-corner fusion is the preferred salvage procedure for Stage III SLAC.

Question 599

Topic: Wrist & Carpus

A 28-year-old tennis player presents with persistent ulnar-sided wrist pain and clicking. MRI reveals an isolated tear of the foveal attachment of the triangular fibrocartilage complex (TFCC). On examination, the distal radioulnar joint (DRUJ) is grossly unstable compared to the contralateral side. What is the most appropriate surgical management?

. Arthroscopic debridement of the TFCC central disk
. Open or arthroscopically-assisted foveal reattachment of the TFCC
. Ulnar shortening osteotomy
. Darrach procedure
. Wafer procedure

Correct Answer & Explanation

. Open or arthroscopically-assisted foveal reattachment of the TFCC

Explanation

A tear of the foveal attachment (the deep fibers of the radioulnar ligaments) of the TFCC is the primary cause of DRUJ instability (Palmer class 1B). Because the DRUJ is unstable, simple debridement is inadequate. Surgical repair via open or arthroscopic foveal reattachment (e.g., using bone anchors or transosseous sutures) is required to restore DRUJ stability.

Question 600

Topic: Wrist & Carpus

A 60-year-old woman with severe rheumatoid arthritis presents with a sudden inability to actively extend her ring and small fingers at the metacarpophalangeal (MCP) joints. The tenodesis effect is completely absent. What is the most likely underlying etiology of this condition?

. Posterior interosseous nerve syndrome secondary to elbow synovitis
. Vaughan-Jackson syndrome
. Subluxation of the extensor tendons into the ulnar valleys
. Ischemic contracture of the extensor muscle bellies
. Rupture of the central slips at the PIP joints

Correct Answer & Explanation

. Vaughan-Jackson syndrome

Explanation

The abrupt loss of active finger extension in a rheumatoid patient with absent tenodesis effect is diagnostic of extensor tendon rupture. Vaughan-Jackson syndrome describes the sequential rupture of the extensor tendons, typically starting ulnarly (EDM and EDC to the small finger) and progressing radially. It is caused by attrition over a dorsally subluxated distal ulna (caput ulnae) due to DRUJ destruction.

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