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7. Hand and Wrist MCQs

Practice Set 10 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 181

Topic: 7. Hand and Wrist

A 22-year-old male falls on an outstretched hand and presents with anatomic snuffbox tenderness. Radiographs show a displaced fracture of the proximal pole of the scaphoid. The high risk of avascular necrosis in this specific location is primarily due to the retrograde intraosseous blood supply from which of the following vessels?

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

Correct Answer & Explanation

. Dorsal carpal branch of the radial artery

Explanation

The scaphoid receives 70-80% of its blood supply in a retrograde fashion from the dorsal carpal branch of the radial artery, which enters the distal pole and waist. Proximal pole fractures disrupt this intraosseous supply, leading to a predictably high rate of avascular necrosis.

Question 182

Topic: 7. Hand and Wrist

A newborn presents with short ribs, short stature, and postaxial polydactyly of the hands. An echocardiogram reveals a single atrium. What is the most likely diagnosis?

. Asphyxiating thoracic dystrophy (Jeune syndrome)
. Chondroectodermal dysplasia (Ellis-van Creveld)
. Cleidocranial dysplasia
. Campomelic dysplasia
. Multiple exostoses

Correct Answer & Explanation

. Chondroectodermal dysplasia (Ellis-van Creveld)

Explanation

Ellis-van Creveld syndrome is a chondroectodermal dysplasia characterized by short-limb dwarfism, postaxial polydactyly, dysplastic nails, and congenital heart defects (most commonly an atrial septal defect or single atrium).

Question 183

Topic: 7. Hand and Wrist

A child with diastrophic dysplasia presents with a classic "hitchhiker thumb" deformity. This deformity is primarily caused by which of the following anatomic abnormalities?

. Radial clubhand with absent radius
. Subluxation of the metacarpophalangeal joint
. A shortened first metacarpal with a radial deviation at the trapeziometacarpal joint
. Agenesis of the thenar musculature
. Fusion of the interphalangeal joint

Correct Answer & Explanation

. A shortened first metacarpal with a radial deviation at the trapeziometacarpal joint

Explanation

The "hitchhiker thumb" in diastrophic dysplasia is caused by a severely shortened, oval-shaped first metacarpal and radial subluxation at the trapeziometacarpal joint. It is a hallmark of this sulfate transporter defect.

Question 184

Topic: 7. Hand and Wrist

An infant is born with a distinctly narrowed, bell-shaped thorax, shortened limbs, and polydactyly. The neonatologist notes severe respiratory distress requiring intubation shortly after birth. Pelvic radiographs show a "trident" appearance of the acetabular roof. What is the most likely diagnosis?

. Achondroplasia
. Asphyxiating thoracic dystrophy (Jeune syndrome)
. Campomelic dysplasia
. Chondroectodermal dysplasia (Ellis-van Creveld syndrome)
. Thanatophoric dysplasia

Correct Answer & Explanation

. Asphyxiating thoracic dystrophy (Jeune syndrome)

Explanation

Jeune syndrome (asphyxiating thoracic dystrophy) presents with a narrow, bell-shaped thorax leading to severe respiratory distress, shortened limbs, and occasionally polydactyly. Radiographs characteristically show a "trident" acetabulum with spurs on the sciatic notch.

Question 185

Topic: 7. Hand and Wrist

The neonatal hand:

. Has no primary ossification centers visible at birth.
. Demonstrates secondary ossification centers from proximal to distal.
. Ossifies the carpus from the margins, centrally.
. Is proportionately different from the mature hand.

Correct Answer & Explanation

. Is proportionately different from the mature hand.

Explanation

The neonatal hand is proportionally different from the mature hand.

Question 186

Topic: 7. Hand and Wrist

In congenital lesions characterized by failure of formation of parts, the most functional, without treatment, is/are:

. Transverse arrest at the wrist.
. C entral deficiencies.
. VATER syndrome.
. Ulnar deficiencies.
. Radial deficiencies

Correct Answer & Explanation

. C entral deficiencies.

Explanation

C entral deficiencies allow a wide grasp, good release and pinch. These are also termed "cleft hand". The other conditions produce greater impairment.

Question 187

Topic: Nerve & Tendon

A 45-year-old laborer complains of numbness in his ring and small fingers and hand weakness. He demonstrates a positive Froment sign when asked to pinch a piece of paper. Which nerve is compressed, and which muscle is compensating?

. Ulnar nerve; flexor pollicis longus
. Median nerve; adductor pollicis
. Ulnar nerve; abductor pollicis brevis
. Radial nerve; extensor pollicis longus
. Median nerve; flexor pollicis brevis

Correct Answer & Explanation

. Ulnar nerve; flexor pollicis longus

Explanation

A positive Froment sign indicates ulnar nerve palsy, leading to weakness of the adductor pollicis. The patient compensates by hyperflexing the thumb interphalangeal joint, a motion powered by the median nerve-innervated flexor pollicis longus (FPL).

Question 188

Topic: 7. Hand and Wrist

A 32-year-old man falls on an outstretched hand and presents with dorsal wrist pain. Radiographs demonstrate a widened scapholunate interval of 5 mm on the AP view. What is the classic eponymous name for this radiographic sign?

. Terry Thomas sign
. Spilled teacup sign
. Piece of pie sign
. Apple core sign
. Fleck sign

Correct Answer & Explanation

. Terry Thomas sign

Explanation

The Terry Thomas sign refers to an abnormally widened scapholunate interval (>3 mm) seen on AP radiographs, indicative of scapholunate ligament dissociation. The "spilled teacup" and "piece of pie" refer to lunate/perilunate dislocations.

Question 189

Topic: 7. Hand and Wrist
A 28-year-old construction worker falls onto an outstretched hand and presents with severe volar wrist swelling. Radiographs reveal a volar displacement of the lunate, appearing as a 'spilled teacup' on the lateral view, while the capitate remains aligned with the radius. What is the sequence of carpal instability leading to this injury according to Mayfield's stages?
. Scapholunate, lunotriquetral, capitlunate, radiolunate
. Lunotriquetral, capitlunate, scapholunate, dorsal radiocarpal
. Scapholunate, capitlunate, lunotriquetral, dorsal radiocarpal
. Capitlunate, scapholunate, lunotriquetral, volar radiocarpal
. Dorsal radiocarpal, scapholunate, capitlunate, lunotriquetral

Correct Answer & Explanation

. Scapholunate, capitlunate, lunotriquetral, dorsal radiocarpal

Explanation

According to Mayfield's progressive perilunate instability, the sequence is Stage I (scapholunate), Stage II (capitolunate), Stage III (lunotriquetral), and Stage IV (failure of the dorsal radiocarpal ligament). This final stage allows the lunate to dislocate volarly into the carpal tunnel.

Question 190

Topic: Nerve & Tendon
The most common nerve injury in a Monteggia fracture and the type of Monteggia fracture with which it is most commonly found is:
. Ulnar nerve, type I
. Posterior interosseous nerve, type IV
. Posterior interosseous nerve, type III
. Median nerve, type I
. Median nerve, type III

Correct Answer & Explanation

. Posterior interosseous nerve, type III

Explanation

The posterior interosseous branch of the radial nerve is injured in 10%-20% of Monteggia fractures. Most cases occur at the time of fracture, but some occur later. Spontaneous resolution is the usual outcome. The posterior interosseous nerve is the most commonly injured, and type I and type III are the most common types affected.

Question 191

Topic: Nerve & Tendon

A physeal fracture-separation of the distal humerus is seen in an 18-month- old boy. When the parents ask about the prognosis after this injury, you tell them that the most common complication is:

. C ubitus varus
. Median nerve palsy
. Ulnar nerve injury
. Brachial artery injury
. Undergrowth of the humerus

Correct Answer & Explanation

. C ubitus varus

Explanation

Cubitus varus occurred in seven out of twelve physeal fracture separations of the distal humerus in one series. This most likely occurred due to malalignment or avascular necrosis of the trochlea. Median nerve injury, ulnar nerve injury, and brachial artery injury are extremely uncommon after this injury because the surfaces of the metaphysis and the physis are relatively smooth in comparison to supracondylar fractures. Also, these injuries are relatively low-energy. Growth plate damage causing undergrowth is rare after this fracture.

Question 192

Topic: Hand Trauma & Infection

A patient presents with a swollen, painful index finger. Which of the following is NOT one of Kanavel's four cardinal signs of acute suppurative flexor tenosynovitis?

. Fusiform swelling of the entire digit
. Exquisite tenderness along the course of the flexor tendon sheath
. Severe pain with passive extension of the digit
. Erythema extending proximal to the wrist crease
. Flexed resting posture of the digit

Correct Answer & Explanation

. Erythema extending proximal to the wrist crease

Explanation

Kanavel's signs include fusiform swelling, tenderness along the sheath, pain on passive extension, and a flexed resting posture. Erythema extending proximal to the wrist is not a cardinal sign and may suggest a more widespread cellulitis or proximal spread.

Question 193

Topic: Nerve & Tendon

In a child with an extension-type supracondylar humerus fracture presenting with significant posteromedial displacement of the distal fragment, which nerve is most commonly at risk of injury?

. Ulnar nerve
. Anterior interosseous nerve (AIN)
. Median nerve
. Radial nerve
. Axillary nerve

Correct Answer & Explanation

. Radial nerve

Explanation

In a posteromedially displaced supracondylar humerus fracture, the proximal fragment displaces anterolaterally, putting the radial nerve at the highest risk of injury. Posterolateral displacement primarily endangers the median nerve and AIN.

Question 194

Topic: Hand Trauma & Infection

Which of the following is NOT one of Kanavel's cardinal signs for flexor tenosynovitis?

. Fusiform swelling of the digit
. Tenderness along the flexor tendon sheath
. Pain with active extension of the digit
. Digit held in a flexed posture
. Pain with passive extension of the digit

Correct Answer & Explanation

. Pain with passive extension of the digit

Explanation

Kanavel's four cardinal signs are: flexed posture of the digit, fusiform swelling, tenderness along the flexor sheath, and severe pain with passive (not active) extension. Pain with active motion is less specific.

Question 195

Topic: 7. Hand and Wrist

Which of the following structures is the most volar structure within the carpal tunnel?

. Median nerve
. Flexor pollicis longus tendon
. Flexor digitorum superficialis tendon to the middle finger
. Flexor digitorum profundus tendons
. Flexor carpi radialis tendon

Correct Answer & Explanation

. Median nerve

Explanation

The median nerve is the most volar (superficial) structure within the carpal tunnel, lying immediately deep to the transverse carpal ligament. The FDS tendons to the middle and ring fingers are immediately dorsal to the nerve.

Question 196

Topic: 7. Hand and Wrist

The splint for early active motion flexor tendon rehabilitation protocols includes:

. A wrist flexion piece
. A dynamic extension outrigger
. A yoke over the affected finger
. A hinge at the wrist to allow a tenodesis effect
. None of the above

Correct Answer & Explanation

. A hinge at the wrist to allow a tenodesis effect

Explanation

A hinge at the wrist, which provides a tenodesis effect, allows the patient to passively extend the wrist and flex the fingers in preparation for gentle muscle contraction of the fingers.

Question 197

Topic: Nerve & Tendon

What deformity can develop in a mistreated volar PIP joint dislocation?

. Swan neck deformity
. Extensor lag
. Boutonniere deformity
. Flexion contracture
. Hyperextension deformity

Correct Answer & Explanation

. Boutonniere deformity

Explanation

With volar PIP joint dislocations, there is almost always a disruption of the central slip of the extensor tendon. Because the central slip is involved, the PIP joint will hold a flexed position, and the lateral bands will fall volar to the axis of rotation of the PIP joint. The lateral bands will then exacerbate the flexion at the PIP joint, and due to their pull on the terminal tendon at the insertion on the distal phalanx, the DIP joint will hyperextend. This results in a boutonniere deformity.

Question 198

Topic: 7. Hand and Wrist

Which structures are disrupted in a lateral PIP joint dislocation?

. Volar plate by itself
. Volar plate and both collateral ligaments
. Volar plate, both collateral ligaments and central slip
. Volar plate and one collateral ligament
. Volar plate and lateral bands

Correct Answer & Explanation

. Volar plate and both collateral ligaments

Explanation

When a lateral PIP joint dislocation occurs, failure probably begins with disruption of the collateral ligament either from its origin on the head of the proximal phalanx or its insertion on the base of the middle phalanx. The injury then proceeds through the accessory collateral ligaments and terminates with disruption of the insertion of the volar plate on the middle phalangeal base.

Question 199

Topic: Nerve & Tendon

The nerve most commonly injured at the time of a supracondylar fracture is:

. Radial nerve
. Median nerve
. Ulnar nerve
. Anterior interosseous nerve
. Posterior interosseous nerve

Correct Answer & Explanation

. Anterior interosseous nerve

Explanation

The anterior interosseous nerve is the most commonly injured nerve. The anterior interosseous nerve can be tested by asking the patient to make an "O" with the thumb and index fingers, and watching for active flexion of the distal interphalangeal joints. The radial nerve is the second most commonly injured, after the anterior interosseous nerve. The ulnar nerve is not the most commonly injured at time of fracture but is the most commonly injured at time of treatment. The posterior interosseous nerve is rarely injured.

Question 200

Topic: Nerve & Tendon
A 28-year-old carpenter suffers a laceration over the dorsal aspect of the proximal interphalangeal (PIP) joint, resulting in a Zone III extensor tendon disruption. If left untreated, this injury will classically lead to which of the following deformities?
. Mallet finger deformity
. Swan neck deformity
. Boutonniere deformity
. Jersey finger deformity
. Quadrigia effect

Correct Answer & Explanation

. Boutonniere deformity

Explanation

A Zone III extensor tendon injury disrupts the central slip attachment at the base of the middle phalanx. This leads to volar subluxation of the lateral bands, causing PIP flexion and DIP hyperextension, known as a Boutonniere deformity.

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