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 101
Topic: 7. Hand and Wrist
A 2-year-old boy is diagnosed with congenital scoliosis secondary to a fully segmented hemivertebra at T8. Which of the following screening tests is most critical for this patient?
Correct Answer & Explanation
. Renal ultrasound
Explanation
Congenital scoliosis is frequently associated with VACTERL anomalies, with genitourinary anomalies occurring in up to 30% of patients. A renal ultrasound is mandatory to rule out unilateral renal agenesis or obstructive uropathy.
Question 102
Topic: Wrist & Carpus
Which of the following is the most common complication after a posttraumatic distal radial growth arrest:
Correct Answer & Explanation
. Positive distal ulnar variance
Explanation
The most common complication after a posttraumatic distal radial growth arrest is positive ulnar variance (overgrowth). Other complications may include decreased distal radial articular angle, triradiate fibrocartilage tear, or distal radioulnar joint instability, but they are less common. Increased radial articular angle and negative ulnar variance rarely develop after these injuries.
Question 103
Topic: 7. Hand and Wrist
In severe carpal tunnel syndrome, which of the following electromyography (EMG) or nerve conduction velocity (NCV) findings is most indicative of irreversible axonal damage?
Correct Answer & Explanation
. Fibrillation potentials in the abductor pollicis brevis
Explanation
Fibrillation potentials and positive sharp waves on EMG indicate active axonal denervation of the muscle, signifying significant and potentially irreversible damage. Prolonged latencies reflect demyelination but not necessarily permanent axonal loss.
Question 104
Topic: Wrist & Carpus
A patient undergoes volar plating for a distal radius fracture. Six months later, the patient cannot actively flex the interphalangeal joint of the thumb. What technical error during the initial surgery is the most likely cause?
Correct Answer & Explanation
. Placing the plate distal to the watershed line
Explanation
Rupture of the flexor pollicis longus (FPL) tendon is a known complication of volar distal radius plating. It most commonly occurs when the plate is placed too distally, crossing the "watershed line," causing mechanical attrition of the tendon.
Question 105
Topic: Nerve & Tendon
A zone II flexor tendon laceration involves both the flexor digitorum profundus (FDP) and superficialis (FDS). Repairing both tendons, rather than the FDP alone, specifically helps prevent which of the following postoperative deformities?
Correct Answer & Explanation
. Swan neck deformity
Explanation
The FDS acts as a primary dynamic stabilizer of the PIP joint against hyperextension. Failing to repair the FDS can lead to PIP joint hyperextension and a subsequent swan neck deformity.
Question 106
Topic: 7. Hand and Wrist
A patient presents with an inability to flex the interphalangeal joint of the thumb and the distal interphalangeal joint of the index finger. Sensation in the hand is intact. Which nerve is most likely compressed, and at what anatomical site?
Correct Answer & Explanation
. Anterior interosseous nerve at the pronator teres
Explanation
The anterior interosseous nerve (AIN) innervates the FPL, FDP to the index/middle fingers, and pronator quadratus. It is purely motor, hence normal sensation; compression frequently occurs at the tendinous edge of the deep head of the pronator teres.
Question 107
Topic: Nerve & Tendon
A 2-year-old child presents with an interphalangeal joint flexion deformity of the right thumb. A nodule is palpable at the volar MCP joint, and passive extension is impossible. What is the recommended treatment at this age if nonoperative measures have failed?
Correct Answer & Explanation
. A1 pulley release
Explanation
Pediatric trigger thumb is caused by a size mismatch between the FPL tendon (Notta's nodule) and the A1 pulley. Surgical release of the A1 pulley is the definitive treatment if stretching and observation fail.
Question 108
Topic: Nerve & Tendon
A 6-year-old boy sustains an extension-type supracondylar fracture of the humerus. Which nerve is most commonly injured in this specific type of fracture overall?
Correct Answer & Explanation
. Anterior interosseous nerve
Explanation
The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar humerus fractures. It is a motor branch of the median nerve that controls the flexor pollicis longus and the flexor digitorum profundus to the index finger.
Question 109
Topic: 7. Hand and Wrist
A 32-year-old black woman presents with a 3-month history of a non-productive cough, dyspnoea and pleuritic chest pain, especially on climbing stairs. She reports intermittent fevers of up to 39 °C and a 3.5-kg weight loss. She complains of wrist and ankle pain that has interfered with her work. She smokes two packets of cigarettes per day. Her full blood count is normal and her serum antinuclear antibody (ANA) is negative. On examination there are red nodules over her lower legs. What is the most likely diagnosis?
Correct Answer & Explanation
. Sarcoidosis
Explanation
Correct Answer: D. Sarcoidosis is most common in black women. It is characterised by the presence of non-caseating granulomas in at least two organs. Clinical manifestations include dry cough, dyspnoea, arthralgias, erythema nodosum, and systemic symptoms like fever and weight loss. The negative ANA and presence of erythema nodosum make sarcoidosis more likely than SLE.
Question 110
Topic: 7. Hand and Wrist
A 24-year-old man presents with radial-sided wrist pain after a fall on an outstretched hand. Radiographs show a displaced fracture of the proximal pole of the scaphoid. Why is this specific fracture pattern at a particularly high risk for avascular necrosis (AVN)?
Correct Answer & Explanation
. Blood supply enters dorsally at the distal pole and flows retrograde
Explanation
The scaphoid receives its primary blood supply from branches of the radial artery that enter distally and dorsally, providing retrograde perfusion to the proximal pole. Proximal pole fractures disrupt this blood supply, causing high rates of AVN.
Question 111
Topic: 7. Hand and Wrist
A 28-year-old carpenter suffers a flexor tendon laceration in Zone II of the hand. Which anatomical boundaries strictly define flexor tendon Zone II?
Correct Answer & Explanation
. Proximal edge of the A1 pulley to the insertion of the flexor digitorum superficialis (FDS)
Explanation
Zone II (historically 'no man\'s land') extends from the proximal edge of the A1 pulley to the insertion of the FDS tendon. Repair in this zone is complex due to both FDS and FDP traversing within a tight fibro-osseous sheath.
Question 112
Topic: 7. Hand and Wrist
A 45-year-old female presents with numbness and tingling in her thumb, index, and long fingers that awakens her at night. Electromyography confirms isolated prolonged sensory latencies in the median nerve at the wrist. Which structure forms the roof of the anatomical space where compression is occurring?
Correct Answer & Explanation
. Transverse carpal ligament
Explanation
The patient has carpal tunnel syndrome. The roof of the carpal tunnel is formed by the transverse carpal ligament, which is surgically released to relieve pressure on the median nerve.
Question 113
Topic: 7. Hand and Wrist
A 20-year-old male sustains a fall on an outstretched hand and complains of radial wrist pain. Clinical examination reveals localized tenderness in the anatomical snuffbox. Radiographs confirm a nondisplaced scaphoid waist fracture. Why is this fracture at a disproportionately high risk for nonunion and avascular necrosis?
Correct Answer & Explanation
. Retrograde blood supply entering the distal pole of the scaphoid
Explanation
The scaphoid receives its primary blood supply from branches of the radial artery that enter distally and flow in a retrograde fashion. Fractures at the waist or proximal pole disrupt this supply, leading to high rates of proximal pole AVN and nonunion.
Question 114
Topic: 7. Hand and Wrist
A rugby player grabs an opponent's jersey and feels a sudden pop in his finger. He is unable to actively flex the distal interphalangeal (DIP) joint of the affected digit. Which finger is most commonly involved in this injury?
Correct Answer & Explanation
. Ring finger
Explanation
A 'jersey finger' is an avulsion of the flexor digitorum profundus (FDP) tendon from the distal phalanx. It most commonly affects the ring finger, as it extends further than the other digits when the hand is gripping.
Question 115
Topic: 7. Hand and Wrist
A 50-year-old man presents with chronic wrist pain. Radiographs reveal Scaphoid Nonunion Advanced Collapse (SNAC) Stage III, characterized by radioscaphoid and capitolunate arthritis, but sparing the radiolunate joint. What is the most appropriate surgical treatment?
Correct Answer & Explanation
. Scaphoid excision and four-corner arthrodesis
Explanation
In SNAC Stage III, arthritis involves the capitolunate joint, which is an absolute contraindication for a proximal row carpectomy. Scaphoid excision and four-corner arthrodesis preserves the healthy radiolunate articulation while eliminating the arthritic joints.
Question 116
Topic: 7. Hand and Wrist
A 38-year-old man with a history of asthma presents with weakness of his right hand and of plantar flexion of his left foot. His asthma is managed with a salmeterol–fluticasone combination inhaler. On examination, his blood pressure is 152/91 mmHg and he has polyphonic wheeze on auscultation of the chest. Investigations: Hb 13.2 g/dL, WCC 8.2 x 10^9/L (raised eosinophils), PLT 180 x 10^9/L, Sodium 139 mmol/L, Potassium 4.3 mmol/L, Creatinine 149 µmol/L. Urine dipstick testing showed blood + and protein +. Which of the following is the most appropriate autoantibody to test for?
Correct Answer: E. Perinuclear anti-neutrophil cytoplasmic antibody (pANCA). About 70% of patients with eosinophilic granulomatosis with polyangiitis have a positive pANCA result. Eosinophilic granulomatosis with polyangiitis presents with symptoms of asthma, and more than 7/10 patients also have mononeuritis multiplex. Renal involvement leads to haematuria and proteinuria, hypertension, and raised creatinine. The raised eosinophil count here is also typical of eosinophilic granulomatosis with polyangiitis. Treatment consists of corticosteroids, with or without additional therapy with cyclophosphamide.
Question 117
Topic: 7. Hand and Wrist
A 24-year-old man falls onto his outstretched hand and presents with anatomic snuffbox tenderness. Initial radiographs are negative for a fracture. What is the most appropriate next step in management?
Correct Answer & Explanation
. Immobilize in a thumb spica splint and repeat radiographs in 10-14 days
Explanation
A clinically suspected scaphoid fracture with negative initial radiographs should be treated with thumb spica immobilization and re-evaluated in 10-14 days. Alternatively, acute MRI can be performed to definitively rule out the fracture and avoid prolonged immobilization.
Question 118
Topic: 7. Hand and Wrist
A 45-year-old pregnant woman presents with numbness and tingling in her thumb, index, and middle fingers, especially at night. Examination reveals a positive Phalen test. What is the most appropriate initial management?
Correct Answer & Explanation
. Volar splinting of the wrist
Explanation
Carpal tunnel syndrome during pregnancy is common due to fluid retention and typically resolves postpartum. Initial management should always be conservative, prioritizing night-time volar wrist splinting to maintain a neutral wrist position and alleviate symptoms.
Question 119
Topic: 7. Hand and Wrist
A 45-year-old man presents with a swollen, painful knee and "sausage-like" swelling of his second and third toes. Radiographs of his hands show classic "pencil-in-cup" deformities of the distal phalanges. What is the most likely diagnosis?
Correct Answer & Explanation
. Psoriatic arthritis
Explanation
Psoriatic arthritis classically presents with dactylitis (sausage digits) and asymmetric oligoarthritis. Radiographic findings include the pathognomonic "pencil-in-cup" deformity caused by severe periarticular erosions and bone resorption.
Question 120
Topic: 7. Hand and Wrist
A 28-year-old carpenter sustains a volar laceration to his index finger over the middle phalanx. Both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons are transected. Into which flexor tendon zone does this injury fall?
Correct Answer & Explanation
. Zone II
Explanation
Zone II extends from the A1 pulley to the insertion of the FDS on the middle phalanx. It contains both the FDS and FDP tendons within a narrow fibro-osseous sheath, making repairs here notoriously prone to adhesions.
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