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7. Hand and Wrist MCQs

Practice Set 220 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 4381

Topic: Wrist & Carpus

The 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized bone graft is commonly used for scaphoid nonunions. This artery courses between which two extensor compartments?

. Abductor pollicis longus/Extensor pollicis brevis and Extensor carpi radialis longus/brevis
. Extensor carpi radialis longus/brevis and Extensor pollicis longus
. Extensor pollicis longus and Extensor digitorum communis
. Extensor digitorum communis and Extensor digiti minimi
. Extensor digiti minimi and Extensor carpi ulnaris

Correct Answer & Explanation

. Abductor pollicis longus/Extensor pollicis brevis and Extensor carpi radialis longus/brevis

Explanation

The 1,2 ICSRA runs longitudinally along the distal radius between the first extensor compartment (APL, EPB) and the second extensor compartment (ECRL, ECRB). It is used as a pedicle for distal radius bone grafts to the scaphoid.

Question 4382

Topic: 7. Hand and Wrist
A patient undergoes a scaphoid excision and four-corner fusion for SNAC Stage III. Which four carpal bones are fused in this procedure?
. Scaphoid, Lunate, Triquetrum, Capitate
. Lunate, Triquetrum, Capitate, Hamate
. Lunate, Capitate, Hamate, Trapezium
. Capitate, Hamate, Trapezium, Trapezoid
. Triquetrum, Pisiform, Capitate, Hamate

Correct Answer & Explanation

. Lunate, Triquetrum, Capitate, Hamate

Explanation

A four-corner fusion involves the arthrodesis of the lunate, triquetrum, capitate, and hamate. The scaphoid is excised to eliminate the arthritic radioscaphoid articulation and correct the carpal mechanics.

Question 4383

Topic: Nerve & Tendon

A volar approach is chosen for open reduction and internal fixation of a scaphoid waist fracture with a humpback deformity. Which interval is utilized to access the scaphoid?

. Between the flexor carpi radialis (FCR) and the radial artery
. Between the flexor carpi ulnaris (FCU) and the ulnar artery
. Between the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB)
. Between the flexor pollicis longus (FPL) and the median nerve
. Between the brachioradialis and the radial artery

Correct Answer & Explanation

. Between the flexor carpi radialis (FCR) and the radial artery

Explanation

The standard volar (Russe) approach to the scaphoid utilizes the interval between the flexor carpi radialis (FCR) tendon and the radial artery. This approach is ideal for placing volar wedge grafts to correct humpback deformities.

Question 4384

Topic: 7. Hand and Wrist

While both SLAC and SNAC wrists result in predictable patterns of carpal arthritis, what key pathophysiologic difference initiates the degenerative cascade in a SNAC wrist?

. Tear of the scapholunate interosseous ligament
. Asymmetric wear of the proximal scaphoid pole against the radial styloid due to scaphoid nonunion
. Loss of vascularity to the lunate
. Primary osteoarthritis of the scaphotrapezial joint
. Ulnar variance leading to ulnocarpal impaction

Correct Answer & Explanation

. Tear of the scapholunate interosseous ligament

Explanation

SNAC arthritis is initiated by the abnormal mechanics of a scaphoid nonunion, causing the distal fragment to rotate and impinge on the radial styloid. In contrast, SLAC arthritis is initiated by an incompetent scapholunate ligament.

Question 4385

Topic: Wrist & Carpus

During a radial styloidectomy for SNAC Stage I arthritis, the surgeon must be careful not to excise more than 3 to 4 mm of the radial styloid. Excessive resection risks destabilizing the carpus by detaching which of the following ligaments?

. Radioscaphocapitate (RSC) ligament
. Scapholunate interosseous ligament
. Lunotriquetral interosseous ligament
. Dorsal radiocarpal ligament
. Ulnocarpal ligament complex

Correct Answer & Explanation

. Radioscaphocapitate (RSC) ligament

Explanation

The radioscaphocapitate (RSC) ligament originates from the radial styloid. Excision of more than 3 to 4 mm of the styloid can compromise the origin of this critical volar stabilizing ligament, leading to ulnar translation of the carpus.

Question 4386

Topic: Wrist & Carpus
A patient presents with a long-standing scaphoid nonunion. CT demonstrates advanced cystic changes and joint space loss at the capitolunate joint, but the radioscaphoid joint is relatively well preserved. What is the most appropriate management principle for this atypical pattern?
. It is managed as a SNAC I with isolated radial styloidectomy
. It requires isolated capitolunate fusion while preserving the scaphoid
. It is managed identically to SLAC I using scapholunate repair
. It is an absolute indication for total wrist arthroplasty regardless of age
. It is managed as a SNAC III equivalent due to capitate involvement, often requiring four-corner fusion

Correct Answer & Explanation

. It is managed as a SNAC III equivalent due to capitate involvement, often requiring four-corner fusion

Explanation

Although SNAC progression typically affects the radioscaphoid joint before the capitolunate joint, isolated capitolunate arthritis with a scaphoid nonunion dictates the same salvage treatment principles as SNAC III. Four-corner fusion is typically required.

Question 4387

Topic: 7. Hand and Wrist

The primary vascular supply to the proximal pole of the scaphoid is derived from which of the following vessels?

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

Correct Answer & Explanation

. Volar carpal branch of the radial artery

Explanation

The scaphoid receives 70 to 80 percent of its blood supply from the dorsal carpal branch of the radial artery, which enters at the dorsal ridge and flows retrograde to supply the proximal pole.

Question 4388

Topic: 7. Hand and Wrist
A patient with a long-standing scaphoid nonunion presents with chronic wrist pain. Radiographs demonstrate arthritis between the radial styloid and the distal scaphoid, as well as joint space narrowing at the scaphocapitate articulation. The capitolunate joint is preserved. This represents which stage of Scaphoid Nonunion Advanced Collapse (SNAC)?
. Stage I
. Stage II
. Stage III
. Stage IV
. Stage V

Correct Answer & Explanation

. Stage II

Explanation

SNAC Stage II involves degenerative changes at the scaphocapitate joint in addition to the radioscaphoid joint. Stage III involves the capitolunate joint, and Stage I is isolated strictly to the radial styloid.

Question 4389

Topic: 7. Hand and Wrist

A 50-year-old patient with Stage II SNAC wrist is being evaluated for a proximal row carpectomy (PRC). Which of the following intraoperative findings would be an absolute contraindication to completing the PRC?

. Erosion of the radial styloid cartilage
. Grade IV chondromalacia of the proximal capitate head
. Degenerative tearing of the scapholunate interosseous ligament
. Arthritis at the radioscaphoid articulation
. A fixed DISI deformity of the lunate

Correct Answer & Explanation

. Erosion of the radial styloid cartilage

Explanation

Proximal row carpectomy relies on a pristine articulation between the proximal capitate and the lunate fossa of the radius. Advanced capitate head arthritis is an absolute contraindication to this salvage procedure.

Question 4390

Topic: 7. Hand and Wrist

A 34-year-old male with a scaphoid proximal pole nonunion has MRI findings of avascular necrosis and a significant structural cavitary defect. Which of the following vascularized bone grafts is best suited to provide both structural support and robust osteogenic potential?

. 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) graft
. Pedicled volar carpal artery graft
. Free medial femoral condyle (MFC) corticocancellous flap
. Pronator quadratus pedicled bone flap
. Dorsal distal radius bone graft pedicled on the 4th extensor compartment artery

Correct Answer & Explanation

. 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) graft

Explanation

The free medial femoral condyle (MFC) flap is ideal for AVN with a structural defect because it provides robust blood supply and strong structural bone, unlike pedicled radius grafts which lack sufficient structural integrity.

Question 4391

Topic: 7. Hand and Wrist
A surgeon is performing a 4-corner arthrodesis for a Stage III SNAC wrist. Prior to definitive fixation, what critical correction must be made to the remaining carpus to optimize postoperative wrist kinematics?
. The capitate must be translated dorsally
. The lunate must be reduced out of its dorsiflexed (DISI) position
. The triquetrum must be excised completely
. The radioscaphoid angle must be fixed at 45 degrees
. The ulnar variance must be neutralized via a shortening osteotomy

Correct Answer & Explanation

. The lunate must be reduced out of its dorsiflexed (DISI) position

Explanation

In a SNAC wrist, the lunate falls into a dorsiflexed (DISI) posture. Reducing the lunate out of extension into a neutral, collinear position before fixation is critical to maximize post-operative wrist motion and grip strength.

Question 4392

Topic: 7. Hand and Wrist

What is the preferred surgical approach for open reduction and internal fixation of an isolated scaphoid proximal pole nonunion without humpback deformity?

. Volar approach through the bed of the FCR
. Dorsal approach preserving the dorsal radiocarpal ligament
. Volar approach through the carpal tunnel
. Dorsal approach splitting the 3rd and 4th extensor compartments
. Radial-sided approach via a 1st extensor compartment release

Correct Answer & Explanation

. Volar approach through the bed of the FCR

Explanation

A dorsal approach (typically between the 3rd and 4th compartments) is preferred for proximal pole pathology. It allows direct visualization of the dorsally located proximal pole and facilitates perpendicular, antegrade screw placement.

Question 4393

Topic: 7. Hand and Wrist

In both SLAC and SNAC patterns of carpal collapse, the radiolunate joint is characteristically spared from early degenerative changes. Which of the following biomechanical principles best explains this phenomenon?

. The radiolunate joint bears less than 10 percent of the axial load across the wrist
. The spherical congruence of the radiolunate joint allows concentric rotation without sheer stress
. The lunate lacks a direct blood supply, preventing osteophyte formation
. The radiolunate ligament provides complete offloading of the cartilage during grip
. The lunate transitions into a volar flexed (VISI) position, moving contact entirely to the dorsal radius

Correct Answer & Explanation

. The radiolunate joint bears less than 10 percent of the axial load across the wrist

Explanation

The radiolunate joint has a highly spherical and congruent morphology. This geometry allows concentric rotation and prevents the abnormal asymmetric shear stresses that cause rapid degeneration in the radioscaphoid joint.

Question 4394

Topic: 7. Hand and Wrist

A 24-year-old elite athlete presents with a symptomatic scaphoid waist nonunion. Radiographs reveal early osteophyte formation strictly isolated to the radial styloid, with no humpback deformity. Which surgical intervention is most appropriate to maximize function?

. Proximal row carpectomy
. Four-corner fusion
. Scaphoid open reduction internal fixation with bone grafting and radial styloidectomy
. Total wrist arthrodesis
. Excision of the proximal pole of the scaphoid

Correct Answer & Explanation

. Proximal row carpectomy

Explanation

For early Stage I SNAC in a young, high-demand patient, radial styloidectomy combined with scaphoid nonunion takedown, grafting, and rigid internal fixation can salvage the scaphoid and halt further carpal collapse.

Question 4395

Topic: 7. Hand and Wrist

A 45-year-old manual laborer with Stage IV SNAC wrist undergoes a total wrist arthrodesis. To optimize functional grip strength, what is the ideal position for fusion of the radiocarpal joint?

. 10 to 15 degrees of extension and 10 degrees of ulnar deviation
. Neutral extension and 20 degrees of radial deviation
. 15 degrees of flexion and neutral deviation
. 30 degrees of extension and 15 degrees of radial deviation
. Neutral extension and neutral deviation

Correct Answer & Explanation

. 10 to 15 degrees of extension and 10 degrees of ulnar deviation

Explanation

Total wrist arthrodesis is optimally positioned in 10 to 15 degrees of extension and 10 degrees of ulnar deviation. This mimics the functional resting position of the wrist and maximizes the mechanical advantage of the extrinsic finger flexors.

Question 4396

Topic: Wrist & Carpus

A 45-year-old man with Scaphoid Nonunion Advanced Collapse (SNAC) Stage II undergoes evaluation for a salvage procedure. He strongly prefers a proximal row carpectomy (PRC) over a four-corner arthrodesis. Which of the following intraoperative findings represents an absolute contraindication to proceeding with a PRC?

. Extensive osteophyte formation at the radial styloid
. Eburnation and loss of articular cartilage on the proximal capitate head
. Sclerosis of the lunate facet of the distal radius
. A scapholunate angle of 75 degrees
. Complete disruption of the scapholunate interosseous ligament

Correct Answer & Explanation

. Extensive osteophyte formation at the radial styloid

Explanation

Proximal row carpectomy relies on a congruent and healthy articulation between the capitate head and the lunate fossa of the radius. Eburnation or severe arthritis of the proximal capitate is an absolute contraindication to PRC, necessitating a four-corner fusion or total wrist arthrodesis instead.

Question 4397

Topic: 7. Hand and Wrist

To accurately assess the true deformity, trabecular bridging, and healing of a scaphoid nonunion, computed tomography (CT) imaging should ideally be reconstructed in which of the following planes?

. Axial and coronal planes relative to the distal radius articular surface
. Sagittal and coronal planes oriented strictly to the longitudinal axis of the scaphoid
. Standard anatomical sagittal and coronal planes of the wrist
. Axial planes parallel to the third metacarpal shaft
. Coronal planes aligned with the radiolunate joint

Correct Answer & Explanation

. Axial and coronal planes relative to the distal radius articular surface

Explanation

The complex oblique orientation of the scaphoid within the carpus requires CT reformats along its true longitudinal axis (parasagittal and paracoronal to the scaphoid itself). Standard wrist planes often miss subtle nonunions or misrepresent the severity of a humpback deformity.

Question 4398

Topic: Wrist & Carpus

In the natural history and progression of Scaphoid Nonunion Advanced Collapse (SNAC), which specific articular surface is classically preserved until the final stage (Stage IV) of pancarpal arthritis?

. Radioscaphoid joint
. Scaphocapitate joint
. Capitolunate joint
. Radiolunate joint
. Trapeziometacarpal joint

Correct Answer & Explanation

. Radioscaphoid joint

Explanation

The radiolunate joint is characteristically spared in both SLAC and SNAC wrists due to the concentric, spherical nature of the lunate fossa, which prevents abnormal translation and shear. It only becomes involved in end-stage (Stage IV) pancarpal arthritis.

Question 4399

Topic: 7. Hand and Wrist

The primary blood supply to the proximal pole of the scaphoid enters through the dorsal ridge and supplies the bone in a retrograde fashion. From which parent vessel does this predominant blood supply originate?

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

Correct Answer & Explanation

. Anterior interosseous artery

Explanation

The dorsal carpal branch of the radial artery enters the scaphoid at the dorsal ridge, supplying the proximal 70-80% of the bone via retrograde flow. This retrograde supply is the primary reason proximal pole fractures have a high rate of nonunion and avascular necrosis.

Question 4400

Topic: 7. Hand and Wrist

A 22-year-old athlete sustains an isolated proximal pole scaphoid fracture that progresses to a nonunion. There is no carpal collapse and no humpback deformity. Which surgical approach provides the best biomechanical and anatomic access for fixation?

. Volar approach utilizing a structural wedge graft
. Dorsal approach preserving the volar radiocarpal ligaments
. Direct lateral approach through the anatomical snuffbox
. Volar approach with a pedicled pronator quadratus graft
. Limited radial styloidectomy approach

Correct Answer & Explanation

. Volar approach utilizing a structural wedge graft

Explanation

A dorsal approach is strongly preferred for proximal pole nonunions because it provides direct access to the proximal pole without dividing the critical volar radiocarpal ligaments. It also allows for mechanically advantageous central screw placement down the long axis of the scaphoid.

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