Orthopedic Hand & Wrist MCQs: FRCS Board Exam Prep

Question 1

A 35-year-old carpenter presents with gradual onset of pain at the base of his thumb, worse with gripping and pinching. Examination reveals tenderness over the radial styloid and pain elicited by passively flexing the thumb into the palm and then ulnarly deviating the wrist. Which of the following conditions is most likely?

Explanation

The clinical presentation describes De Quervain's Tenosynovitis, an inflammatory condition affecting the abductor pollicis longus and extensor pollicis brevis tendons within the first dorsal compartment. The Finkelstein's test (flexing the thumb into the palm and then ulnarly deviating the wrist) specifically elicits pain in this condition. Carpal Tunnel Syndrome involves median nerve compression. Intersection Syndrome involves inflammation where the first and second dorsal compartment tendons cross. Thumb CMC OA pain is typically at the joint, with positive grind test. Wartenberg's Syndrome is superficial radial nerve irritation.

Question 2

A 48-year-old male presents with a palpable, painless mass on the dorsum of his wrist, which transilluminates. It is soft and slightly mobile. What is the most common diagnosis?

Explanation

The description of a palpable, painless, transilluminating, soft, and slightly mobile mass on the dorsum of the wrist is classic for a dorsal wrist ganglion cyst. These are the most common soft tissue tumors of the hand and wrist, arising from joint capsules or tendon sheaths. Giant cell tumor of tendon sheath is typically solid and does not transilluminate. Epidermoid cysts can occur but are less common and may not transilluminate as clearly. Lipomas are rare in the wrist, and soft tissue sarcomas are exceedingly rare and typically have more concerning features.

Question 3

A 28-year-old rugby player sustains a hyperextension injury to his thumb during a tackle. Examination reveals significant swelling and tenderness over the ulnar aspect of the thumb metacarpophalangeal (MCP) joint, with instability on valgus stress testing at 30 degrees of flexion. What is the most appropriate initial management?

Explanation

The patient's presentation strongly suggests a complete rupture of the ulnar collateral ligament (UCL) of the thumb MCP joint, commonly known as 'Skier's Thumb' or 'Gamekeeper's Thumb'. Instability at 30 degrees of flexion is indicative of a complete tear. A Stener lesion, where the adductor aponeurosis interposes between the torn UCL and its insertion, preventing healing, is common and necessitates surgical repair. While MRI can confirm a Stener lesion, significant instability on stress testing warrants surgical repair as initial management due to the high likelihood of a Stener lesion or complete tear requiring fixation. Non-operative management is typically reserved for partial tears or stable injuries.

Question 4

A 60-year-old diabetic patient presents with a history of his ring finger catching and locking in flexion, especially in the morning. He describes needing to manually extend it with a 'pop'. Physical examination confirms a palpable nodule at the base of the ring finger on the palmar aspect, consistent with tenosynovitis of which tendon?

Explanation

This classic presentation describes 'trigger finger' (stenosing tenosynovitis), which most commonly affects the flexor digitorum superficialis (FDS) and/or profundus (FDP) tendons at the A1 pulley level. The locking and palpable nodule are characteristic findings. While both FDS and FDP are involved, the FDS is often the primary culprit due to its more superficial location and larger bulk at this level. The FPL can be involved in trigger thumb. Extensor tendons are on the dorsum, and the Palmaris Longus has no role in finger flexion.

Question 5

Which carpal bone is most commonly fractured?

Explanation

The scaphoid is by far the most commonly fractured carpal bone, accounting for 60-70% of all carpal fractures. Its unique blood supply (proximal pole supplied by branches entering distally) predisposes it to avascular necrosis and nonunion. Lunate, Triquetrum, Trapezium, and Capitate fractures are less common.

Question 6

A 40-year-old construction worker presents with acute onset of severe pain, swelling, and redness over the palmar aspect of his index finger DIP joint, following a minor puncture wound. He is febrile. Examination reveals a tense, exquisitely tender, fusiform swelling of the entire finger with marked pain on passive extension. What is the most appropriate immediate management?

Explanation

This is a classic presentation of suppurative flexor tenosynovitis (Kanavel's signs: fusiform swelling, uniform tenderness along tendon sheath, pain on passive extension, flexed posture). This is a surgical emergency. Delay in treatment can lead to tendon necrosis, adhesions, and permanent functional deficits. Immediate incision and drainage of the tendon sheath, along with intravenous antibiotics, are crucial. Oral antibiotics alone are insufficient for an established infection of this severity.

Question 7

A 22-year-old college athlete presents after falling onto an outstretched hand, resulting in a dorsal dislocation of the lunate bone. Which of the following nerves is at highest risk of acute compression?

Explanation

Dorsal lunate dislocation (often actually a perilunate dislocation with lunate volarly displaced, or a pure lunate dislocation where the lunate dislocates volarly into the carpal tunnel) places significant pressure on the median nerve as it passes through the carpal tunnel. The median nerve is highly susceptible to acute compression in these injuries due to its anatomical proximity to the carpus. Radial and ulnar nerves are less directly affected by isolated lunate dislocations. AIN and PIN are branches and are less commonly compressed acutely by this specific injury.

Question 8

Which type of distal radius fracture is characterized by a dorsal displacement of the distal fragment?

Explanation

Colles' fracture is a common extra-articular fracture of the distal radius with dorsal angulation and displacement of the distal fragment. Smith's fracture (reverse Colles') involves volar displacement. Barton's fracture is an intra-articular fracture involving the dorsal or volar rim of the radius. Chauffeur's (Hutchinson) fracture is an oblique fracture of the radial styloid. Galeazzi fracture is a fracture of the radial shaft with dislocation of the distal radioulnar joint (DRUJ).

Question 9

A patient undergoing carpal tunnel release complains of persistent numbness in the thumb, index, and middle fingers immediately post-operatively, despite successful surgical decompression. Which of the following is the most likely explanation?

Explanation

Persistent numbness immediately post-operatively after a technically successful carpal tunnel release, especially in cases with long-standing or severe pre-operative compression, is most often due to the slow recovery of a severely compressed median nerve with Wallerian degeneration. Nerve recovery can take weeks to months, and some degree of residual numbness may persist. Incomplete release is possible but usually leads to continued typical CTS symptoms. Median nerve transection is a catastrophic, rare complication. Superficial palmar arch injury would cause vascular compromise. Ulnar nerve injury would affect different digits.

Question 10

A 55-year-old man presents with progressive inability to fully extend his ring finger, accompanied by a firm nodule in his palmar fascia. Over time, he develops a fixed flexion contracture of the ring finger MCP and PIP joints. What is the most definitive treatment for a severe contracture causing functional impairment?

Explanation

This describes Dupuytren's contracture. For severe contractures causing functional impairment, segmental fasciectomy (or partial fasciectomy) remains the gold standard for definitive treatment, offering the most complete and longest-lasting release, especially for established contractures. Enzyme injection and percutaneous needle fasciotomy are less invasive options that are effective for certain types of cords and less severe contractures but have higher recurrence rates. Steroid injections are generally ineffective, and splinting alone cannot reverse established contractures.

Question 11

A 30-year-old presents with a crushing injury to his hand. He has severe pain, swelling, and a rapidly developing compartment syndrome. Which of the following intrinsic muscles of the hand are not typically contained within the interosseous compartments that are most commonly affected?

Explanation

The thenar muscles (abductor pollicis brevis, flexor pollicis brevis, opponens pollicis) are located in the thenar compartment, which is separate from the interosseous compartments (dorsal and palmar) and the hypothenar compartment. The dorsal and palmar interossei, adductor pollicis, and lumbricals are all contained within or intimately associated with the interosseous compartments, making them primary contributors to and victims of hand compartment syndrome.

Question 12

A 45-year-old female presents with a chronic, progressively worsening painful wrist, especially on the ulnar side. X-rays show positive ulnar variance and degenerative changes at the distal radioulnar joint (DRUJ) and ulnocarpal articulation. Which condition is most likely?

Explanation

Ulnar impaction syndrome (also known as ulnar abutment syndrome) is caused by repetitive loading and degenerative changes between the ulnar head, TFCC, lunate, and triquetrum, often associated with positive ulnar variance. This results in ulnar-sided wrist pain. Kienbock's disease is avascular necrosis of the lunate. Preiser's disease is avascular necrosis of the scaphoid. A TFCC tear can cause ulnar pain but is often a component of ulnar impaction or can occur in isolation. SLAC wrist involves scapholunate ligament disruption and subsequent arthritis, typically radial-sided initially.

Question 13

Which of the following ligaments is considered the most important stabilizer of the distal radioulnar joint (DRUJ)?

Explanation

The Triangular Fibrocartilage Complex (TFCC) is the primary stabilizer of the DRUJ and the ulnar side of the wrist. It consists of the articular disc, dorsal and volar radioulnar ligaments, and the meniscal homologue. The radiocarpal and ulnar/radial collateral ligaments primarily stabilize the radiocarpal joint but have less direct influence on DRUJ stability.

Question 14

A 65-year-old patient with rheumatoid arthritis develops a 'boutonniere deformity' in her middle finger. This deformity is characterized by which of the following?

Explanation

A boutonniere deformity is characterized by a fixed flexion deformity of the proximal interphalangeal (PIP) joint and compensatory hyperextension of the distal interphalangeal (DIP) joint. It results from disruption of the central slip of the extensor mechanism, allowing the lateral bands to migrate volarly and become PIP joint flexors.

Question 15

A 10-year-old boy presents with a 'jersey finger' injury after his finger was caught in an opponent's jersey during a soccer match. This injury most commonly involves avulsion of which tendon?

Explanation

'Jersey finger' is an avulsion of the flexor digitorum profundus (FDP) tendon from its insertion on the distal phalanx. It most commonly affects the ring finger. The patient is unable to actively flex the DIP joint while the PIP joint is stabilized. Surgical repair is typically required.

Question 16

Which of the following conditions is an indication for surgical decompression in Carpal Tunnel Syndrome?

Explanation

Thenar muscle atrophy with objective motor weakness (strength less than M4/5) is a strong indication for surgical decompression of the median nerve to prevent irreversible motor loss. Mild symptoms, intermittent paresthesias, or purely sensory deficits without motor involvement can often be managed conservatively initially. While nerve conduction studies confirming severe sensory deficits can indicate surgery, motor involvement is a more urgent indicator.

Question 17

A patient sustains an open fracture of the proximal phalanx of the small finger. Following debridement and fixation, prophylactic antibiotics are typically administered. Which of the following is the most appropriate empirical antibiotic choice for an open hand fracture?

Explanation

Cefazolin (a first-generation cephalosporin) is the most appropriate empirical antibiotic for open fractures, including those of the hand. It provides excellent coverage against Gram-positive organisms, particularly Staphylococcus aureus, which is the most common pathogen in open fractures. Vancomycin is reserved for MRSA. Ciprofloxacin and Metronidazole have different spectrums and are not first-line for this indication.

Question 18

A 25-year-old presents with a 'mallet finger' injury after jamming his finger while playing basketball. This injury involves disruption of which anatomical structure?

Explanation

A mallet finger results from disruption of the extensor digitorum communis (EDC) tendon insertion into the dorsal base of the distal phalanx (Zone 1 extensor injury), leading to an inability to actively extend the DIP joint. This can be a tendinous avulsion or an osseous avulsion. The central slip is involved in boutonniere deformity. FDP tendon avulsion is a 'jersey finger'. Ligament injuries are different pathologies.

Question 19

Which anatomical structure forms the roof of the carpal tunnel?

Explanation

The transverse carpal ligament (also known as the flexor retinaculum) forms the robust fibrous roof of the carpal tunnel. The floor and walls are formed by the carpal bones. The structures within the carpal tunnel include the median nerve and nine flexor tendons. The Palmaris Longus tendon lies superficial to the transverse carpal ligament in many individuals. The flexor retinaculum of Guyon's canal is for the ulnar nerve and artery, not the carpal tunnel. The deep palmar arch is distal.

Question 20

A 70-year-old female sustains a comminuted, intra-articular distal radius fracture that is irreducible with closed reduction attempts. She has severe osteoporosis. What is generally considered the most appropriate surgical management for this fracture in an active patient?

Explanation

For comminuted, intra-articular, irreducible distal radius fractures, especially in osteoporotic bone, open reduction and internal fixation (ORIF) with a volar locking plate has become the gold standard. Volar locking plates provide stable fixation, allow for early range of motion, and can effectively hold fragments in osteoporotic bone. External fixation can be used but often requires supplementary K-wires and may not achieve anatomical reduction of intra-articular fragments as well. Cast immobilization alone is insufficient for unstable, intra-articular fractures. Ulnar shortening osteotomy addresses ulnar-sided issues, not primarily distal radius fracture fixation.

Question 21

What is the most common site for an enchondroma in the hand?

Explanation

Enchondromas are the most common benign bone tumors of the hand, and they most frequently occur in the proximal phalanges, followed by the metacarpals and middle phalanges. Distal phalanges and carpal bones are less common sites.

Question 22

A 40-year-old patient presents with a history of recurrent episodes of white, then blue, then red discoloration of her fingers, particularly in cold weather or with stress. She denies joint pain or swelling. What is the most likely diagnosis?

Explanation

The classic 'triphasic' color change (pallor, cyanosis, rubor) of the digits in response to cold or stress is pathognomonic for Raynaud's Phenomenon. This is a vasospastic disorder. Vibration white finger is a form of Raynaud's secondary to occupational exposure. Hypothenar Hammer Syndrome is an injury to the ulnar artery. Carpal Tunnel Syndrome involves nerve compression. Erythromelalgia is a rare condition causing burning pain and redness, typically in the feet.

Question 23

What is the primary function of the extensor indicis proprius (EIP) muscle?

Explanation

The Extensor Indicis Proprius (EIP) is an accessory extensor of the index finger, allowing for independent extension of the index finger apart from the other digits. It originates from the posterior aspect of the ulna and interosseous membrane and inserts into the extensor mechanism of the index finger, medial to the extensor digitorum communis (EDC) tendon.

Question 24

A 50-year-old man presents with chronic pain and stiffness in his dominant wrist. X-rays show sclerosis, fragmentation, and collapse of the lunate bone. What is this condition called?

Explanation

Kienbock's disease is avascular necrosis (osteonecrosis) of the lunate bone, leading to its collapse and fragmentation, and eventually carpal arthritis. Preiser's disease is avascular necrosis of the scaphoid. Madelung's deformity is a congenital malformation of the distal radius and ulna. DRUJ arthritis and SLAC wrist are types of arthritis but not primary avascular necrosis of the lunate.

Question 25

A patient with a high median nerve injury (e.g., at the elbow) would typically present with a characteristic 'ape hand' deformity. Which muscle is primarily responsible for the thenar eminence wasting seen in this deformity?

Explanation

The 'ape hand' deformity, characterized by the inability to abduct and oppose the thumb and wasting of the thenar eminence, results from median nerve palsy. The abductor pollicis brevis (APB) is the most superficial and often the first thenar muscle to show atrophy due to median nerve compression, playing a crucial role in thumb abduction and opposition. Adductor Pollicis is ulnar nerve innervated. FPL is median nerve (AIN branch) but less related to thenar bulk. Interossei are ulnar nerve. EPB is radial nerve.

Question 26

Which of the following describes a typical finding of a 'Swan Neck' deformity of a finger?

Explanation

A Swan Neck deformity is characterized by hyperextension of the proximal interphalangeal (PIP) joint and compensatory flexion of the distal interphalangeal (DIP) joint. This deformity is often seen in rheumatoid arthritis due to imbalances in the extensor mechanism. The boutonniere deformity has the opposite PIP/DIP joint positions.

Question 27

A 20-year-old male sustains a fall directly onto his palm with the wrist extended. He presents with pain and swelling at the base of the thumb. Radiographs show an intra-articular fracture of the base of the first metacarpal with subluxation of the carpometacarpal (CMC) joint. What is this fracture called?

Explanation

Bennett's fracture is an intra-articular fracture-dislocation of the base of the first metacarpal. It is an oblique fracture that separates a small palmar-ulnar fragment, which remains attached to the anterior oblique ligament, from the rest of the metacarpal base, which subluxates radially and dorsally. Rolando's fracture is a comminuted intra-articular fracture of the first metacarpal base. Boxer's fracture is a neck fracture of the 5th metacarpal. Barton's and Smith's fractures are distal radius fractures.

Question 28

The Foucher's sign (lack of DIP flexion when the PIP joint is actively flexed) is used to assess the integrity of which tendon?

Explanation

Foucher's sign (or the isolated FDS test) assesses the integrity of the flexor digitorum superficialis (FDS) tendon. When the fingers are held in full extension (blocking the FDS of adjacent fingers), the patient is asked to flex a single finger at the PIP joint. If the FDS is intact, the PIP joint will flex. If the FDS is ruptured, this isolated PIP flexion will be absent or significantly weak, and the DIP joint will also fail to flex (as FDP would also be stretched).

Question 29

A patient presents with a crush injury to the hand. Examination reveals complete loss of sensation over the ulnar half of the ring finger and the entire small finger, and weakness in finger abduction and adduction. There is also marked wasting of the hypothenar eminence. Which nerve is most likely injured?

Explanation

This clinical picture is classic for an ulnar nerve injury. The ulnar nerve innervates the hypothenar muscles (causing wasting), all interossei (responsible for finger abduction/adduction), the medial two lumbricals, and provides sensation to the ulnar half of the ring finger and the entire small finger. Median nerve injury affects the radial three digits and thenar muscles. Radial nerve injury affects wrist/finger extensors and dorsum of hand sensation. AIN is a motor branch of the median nerve. PIN is a motor branch of the radial nerve.

Question 30

Which of the following statements regarding a Ganglion Cyst of the wrist is FALSE?

Explanation

While excision can provide symptomatic relief and is often performed for cosmetic or persistent symptoms, it is not always required. Aspiration is a common non-surgical treatment, and many ganglions can spontaneously resolve. The other statements are true: they are typically filled with mucinous, jelly-like fluid (similar to synovial fluid), are the most common soft tissue tumor, dorsal are more common, and they arise from synovial linings.

Question 31

A 3-year-old child presents with a congenital hand anomaly characterized by a permanently bent little finger, usually at the PIP joint, with radial deviation. The finger cannot be fully straightened passively or actively. What is this condition called?

Explanation

The description perfectly matches Camptodactyly, a congenital flexion contracture of the PIP joint, most commonly affecting the little finger. It is often non-progressive or slowly progressive. Clinodactyly is angular deviation of a digit in the radioulnar plane (often radial deviation of the small finger due to an abnormally shaped middle phalanx). Polydactyly is extra digits. Syndactyly is fused digits. Macrodactyly is enlarged digits.

Question 32

In a patient presenting with a fractured hook of the hamate, which of the following nerves is at greatest risk of injury?

Explanation

The ulnar nerve and artery pass through Guyon's canal, which is bounded radially by the hook of the hamate. Fractures of the hook of the hamate can directly injure or cause compression of the ulnar nerve, leading to symptoms such as paresthesias in the small finger and ulnar half of the ring finger, and weakness of ulnar-innervated intrinsic muscles. Median and radial nerves are not in direct proximity.

Question 33

A 30-year-old presents with a 'clenched fist injury' after punching someone in the mouth. Examination reveals swelling, pain, and a laceration over the dorsum of the MCP joint of the index finger. What is the most critical immediate concern in management?

Explanation

Clenched fist injuries, also known as 'fight bites,' are notorious for high rates of infection, particularly septic arthritis of the MCP joint, due to inoculation of oral flora into the joint or tendon sheath through the small puncture wound. Retained tooth fragments are also common. Therefore, meticulous wound debridement, irrigation, antibiotics, and surgical exploration to rule out joint capsule violation and foreign bodies are crucial. While fractures, ligamentous injuries, and tendon ruptures can occur, the immediate priority is to prevent and treat potentially devastating infection.

Question 34

Which of the following structures is most commonly affected in 'tennis elbow' (lateral epicondylitis)?

Explanation

Lateral epicondylitis, or 'tennis elbow,' is a degenerative tendinopathy (not purely inflammatory) primarily affecting the origin of the extensor carpi radialis brevis (ECRB) tendon at the lateral epicondyle. While other extensors can be involved, ECRB is consistently the most affected. The other muscles listed are either flexors, other extensors, or not primarily involved.

Question 35

A patient presents with a painful, exquisitely tender, reddish-blue spot under the nail of her index finger that is sensitive to cold and light touch. What is the most likely diagnosis?

Explanation

The classic triad of symptoms for a glomus tumor includes severe pain, cold sensitivity, and pin-point tenderness, often described as an 'electric shock.' It typically appears as a small, reddish-blue lesion under the nail. Subungual hematoma results from trauma. Melanoma and SCC are malignant lesions, often with different presentations. Warts are benign epithelial growths.

Question 36

Which of the following ligaments is primarily responsible for preventing dorsal intercalated segment instability (DISI) of the carpus?

Explanation

The scapholunate interosseous ligament (SLIL) is the most important stabilizer of the scaphoid and lunate. A tear of the SLIL allows the scaphoid to flex and the lunate to extend, resulting in dorsal intercalated segment instability (DISI), where the lunate extends dorsally. The lunotriquetral ligament prevents volar intercalated segment instability (VISI). The other ligaments have different stabilizing roles.

Question 37

A patient with a radial nerve injury at the spiral groove would typically exhibit which of the following deficits?

Explanation

A radial nerve injury at the spiral groove (mid-humerus) typically spares the triceps but affects the extensor muscles of the wrist and fingers, leading to a characteristic 'wrist drop' and inability to extend the metacarpophalangeal (MCP) joints. Sensation over the dorsum of the hand and radial aspect of the thumb is also affected. Inability to flex the wrist is typically median or ulnar nerve. Weakness in finger abduction/adduction and ulnar hand sensation loss are ulnar nerve. Thenar atrophy is median nerve.

Question 38

What is the primary anatomical difference between Polydactyly and Syndactyly?

Explanation

Polydactyly refers to the presence of extra digits (supernumerary fingers or toes). Syndactyly refers to the fusion or webbing between adjacent digits. These are distinct congenital hand anomalies. The other options describe incorrect definitions.

Question 39

Which anatomical structure is responsible for stabilizing the first carpometacarpal (CMC) joint of the thumb, preventing dorsal and radial subluxation?

Explanation

The anterior oblique ligament (often called the 'Beak ligament') is the primary stabilizer of the thumb CMC joint, resisting dorsal and radial subluxation. It originates from the palmar aspect of the trapezium and inserts onto the palmar-ulnar aspect of the first metacarpal base. Its integrity is crucial for the stability of the thumb CMC joint, and it is often disrupted in Bennett's fractures. The UCL and RCL of the thumb are MCP joint ligaments.

Question 40

A patient presents with persistent pain, redness, and swelling in the DIP joint of the small finger, accompanied by a 'sausage digit' appearance. He has a history of psoriasis. What is the most likely diagnosis?

Explanation

The combination of dactylitis ('sausage digit' swelling of an entire finger) affecting the DIP joints, especially in a patient with psoriasis, is highly characteristic of Psoriatic Arthritis. While gout can cause acute inflammation, it's typically monoarticular. RA rarely affects DIP joints primarily and typically causes symmetrical polyarthritis. Septic arthritis would be more acute and have systemic signs. Osteoarthritis involves cartilage degeneration without such inflammatory signs.

Question 41

A 40-year-old male presents with acute pain and swelling at the base of his thumb, worse with movement. Examination reveals tenderness localized to the extensor pollicis longus (EPL) tendon where it crosses the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons. What is the most likely diagnosis?

Explanation

Intersection Syndrome (also known as 'squeaker's wrist' or 'oarsman's wrist') is an inflammatory condition affecting the crossing point of the first dorsal compartment tendons (APL, EPB) and the second dorsal compartment tendons (ECRL, ECRB). The pain described in the question, however, is at the crossing point of the third dorsal compartment tendon (EPL) over the second dorsal compartment tendons (ECRL, ECRB), which is known as proximal intersection syndrome (or sometimes referred to as intersection syndrome if referring to the more common distal intersection of APL/EPB over ECRL/ECRB is not the case). The question specified EPL over ECRL/ECRB. De Quervain's affects the first dorsal compartment (APL, EPB). The scenario describes a variant of intersection syndrome. Given the options, Intersection Syndrome is the best fit, despite the nuance of the specific tendons mentioned (often 'distal' intersection syndrome is what is implied, involving APL/EPB crossing ECRL/ECRB more proximally). Proximal Intersection syndrome involves EPL crossing ECRL/ECRB tendons.

Question 42

What is the most common carpal instability pattern?

Explanation

Dorsal Intercalated Segment Instability (DISI) is the most common carpal instability pattern. It is typically caused by a disruption of the scapholunate interosseous ligament, allowing the scaphoid to flex and the lunate to extend dorsally. VISI is less common and results from lunotriquetral ligament disruption. Perilunate dislocation is an acute, traumatic event, not an instability pattern itself but a severe form of carpal disruption that can lead to DISI if not reduced correctly.

Question 43

A patient is unable to make an 'OK' sign, with compensatory hyperextension of the MCP joint of the thumb and index finger. This is indicative of a lesion to which nerve branch?

Explanation

Inability to make a proper 'OK' sign (often appearing as a flattened or 'pincer' grasp, not a true circle) with compensatory hyperextension of the MCP joints of the thumb and index finger suggests weakness of the flexor pollicis longus (FPL) and the flexor digitorum profundus (FDP) to the index finger. Both of these muscles are innervated by the Anterior Interosseous Nerve (AIN), a pure motor branch of the median nerve. A high median nerve injury would also cause this, but the AIN syndrome specifically refers to this isolated motor deficit without sensory loss.

Question 44

What is the primary indication for non-operative management of a stable, non-displaced scaphoid fracture?

Explanation

Stable, non-displaced scaphoid fractures are typically managed non-operatively with a long arm thumb spica cast for 6 weeks, followed by a short arm thumb spica cast for another 6 weeks, or until radiographic evidence of union is seen (total 8-12+ weeks). Due to the scaphoid's tenuous blood supply and high nonunion rate, prolonged immobilization is often necessary. Short immobilization periods or early mobilization risk nonunion.

Question 45

A 6-year-old child presents with a 'delta phalanx' of the small finger. This anomaly is characterized by which of the following?

Explanation

A delta phalanx is a congenital bone anomaly characterized by a triangularly shaped phalanx that has a C-shaped epiphysis (or bar of bone) that extends longitudinally, preventing normal growth and leading to angular deformity (clinodactyly) of the affected digit. It is commonly associated with polydactyly or syndactyly, often affecting the middle phalanx of the small finger or the proximal phalanx of the thumb.

Question 46

Which is the most common complication following excision of a dorsal wrist ganglion?

Explanation

Despite successful surgical excision, recurrence remains the most common complication of dorsal wrist ganglion removal, with rates varying but generally quoted around 5-15%. While nerve injury (e.g., to the superficial radial nerve) and stiffness are potential complications, recurrence is reported most frequently. Infection and vascular injury are rarer.

Question 47

A patient presents with a painful mass in the palm, distal to the carpal tunnel, which is confirmed to be a giant cell tumor of the tendon sheath. Which finger is most commonly affected by this benign tumor?

Explanation

Giant cell tumor of the tendon sheath (GCTTS), also known as pigmented villonodular synovitis (PVNS) in diffuse form, is the second most common soft tissue tumor of the hand after ganglion cysts. It most commonly affects the index finger, followed by the thumb. It typically presents as a firm, non-tender, slowly growing mass. Surgical excision is the treatment, but recurrence is possible.

Question 48

Which of the following conditions is most likely to be successfully treated with only a single corticosteroid injection?

Explanation

Trigger finger (stenosing tenosynovitis) in its early stages, particularly with a palpable nodule and catching, often responds well to a single corticosteroid injection into the tendon sheath. Success rates are generally high (up to 60-90%). Severe CTS with thenar atrophy requires surgical decompression. Dupuytren's contracture cannot be cured by injection once fixed. Septic arthritis requires surgical drainage and antibiotics. A complete UCL tear (especially with a Stener lesion) requires surgical repair.

Question 49

A 50-year-old male sustains a distal phalanx fracture of his ring finger. The fracture is non-displaced and involves the nailbed. What is the most important aspect of initial management to prevent long-term complications?

Explanation

Distal phalanx fractures, especially those involving the nailbed (Seymour fractures or crushing injuries), have a high risk of complications if the nailbed injury is not addressed. A subungual hematoma often indicates a nailbed laceration. Prompt evacuation of the hematoma and meticulous repair of the nailbed are crucial to prevent infection, nail deformities, and osteomyelitis. Operative fixation is rarely needed for non-displaced fractures. Splinting should be protective, but nailbed repair is paramount. Antibiotics may be used, but surgical repair is the key step.

Question 50

Which anatomical landmark is used to differentiate a high median nerve lesion from a low (wrist level) median nerve lesion?

Explanation

The thenar eminence receives its sensory innervation from the palmar cutaneous branch of the median nerve, which typically arises proximal to the transverse carpal ligament and passes superficial to it. Therefore, a high median nerve lesion (e.g., at the elbow or forearm) will result in sensory loss over the thenar eminence, while a low lesion (carpal tunnel syndrome) typically spares thenar eminence sensation. The other options are either not specific for distinguishing high vs. low lesions or relate to different nerve pathologies (e.g., hypothenar wasting and adductor pollicis weakness are ulnar nerve signs).

Question 51

The presence of a 'positive grind test' in the thumb is indicative of pathology in which joint?

Explanation

A positive grind test (axial compression and rotation of the first metacarpal on the trapezium, eliciting pain and crepitus) is a hallmark sign of osteoarthritis of the first carpometacarpal (CMC) joint of the thumb. This is a very common degenerative condition. The other joints are distinct and would have different provocative tests.

Question 52

What is the primary vascular supply to the scaphoid bone?

Explanation

The scaphoid bone has a unique and precarious blood supply, primarily from branches of the radial artery that enter distally. These vessels travel proximally, supplying the majority of the bone, including the proximal pole. This distal entry and retrograde flow explain why the proximal pole is particularly vulnerable to avascular necrosis following a fracture, as its blood supply can be disrupted.

Question 53

A 25-year-old weightlifter presents with ulnar-sided wrist pain, worse with gripping and pronation/supination. Examination reveals tenderness over the distal ulna and a positive 'fovea sign' (tenderness in the depression between the ulnar styloid and flexor carpi ulnaris tendon). Which of the following is the most likely diagnosis?

Explanation

The clinical presentation, particularly the ulnar-sided wrist pain exacerbated by gripping and pronation/supination, and a positive fovea sign, are highly indicative of a Triangular Fibrocartilage Complex (TFCC) tear. The TFCC is a primary stabilizer of the DRUJ and the ulnar carpus. Pisotriquetral arthritis causes pain more volar and distal. Ulnar collateral ligament sprains are less common in the wrist itself. ECU subluxation often presents with snapping. Lunotriquetral instability also causes ulnar-sided pain, but the fovea sign is more specific to TFCC.

Question 54

Which of the following statements about the lumbrical muscles of the hand is true?

Explanation

The lumbricals are unique intrinsic muscles that originate from the flexor digitorum profundus tendons and insert into the extensor hood mechanism. Their primary action is to flex the metacarpophalangeal (MCP) joints and extend the proximal and distal interphalangeal (PIP and DIP) joints. The lateral two lumbricals are innervated by the median nerve, and the medial two by the ulnar nerve (not all by ulnar). They are intrinsic muscles, not extrinsic. Finger abduction is primarily by the dorsal interossei.

Question 55

A patient with a significant crush injury to the hand is unable to perform active finger extension, despite an intact radial nerve and no obvious tendon laceration. There is also marked swelling and tenderness in the dorsal hand. What is the most likely diagnosis?

Explanation

Compartment syndrome can occur in the hand, affecting both intrinsic muscle compartments and, less commonly, the extrinsic compartments, including the dorsal extrinsic compartment. Marked swelling and pain, coupled with neurological deficits (like inability to extend digits despite intact proximal nerve), should raise high suspicion for compartment syndrome. Extensor tendon rupture would typically have an obvious laceration or mechanism of rupture. Dorsal wrist ganglion is a benign mass. Superficial radial nerve compression causes sensory loss. Joint capsular tear does not explain the widespread deficit.

Question 56

Which intrinsic muscle of the thumb is innervated by both the median and ulnar nerves in a variable proportion?

Explanation

The Flexor Pollicis Brevis (FPB) muscle of the thumb thenar eminence is classically described as having dual innervation. Its superficial head is typically innervated by the median nerve, while its deep head often receives innervation from the ulnar nerve. This dual supply is responsible for variations in clinical findings in median or ulnar nerve palsies. APB and Opponens Pollicis are primarily median. Adductor Pollicis is solely ulnar. EPB is radial (extrinsic).

Question 57

What is the most common direction of thumb carpometacarpal (CMC) joint dislocation?

Explanation

Dorsal dislocation is the most common direction for the thumb carpometacarpal (CMC) joint. This typically occurs from a direct force or an axial load on a flexed and adducted thumb. Volar, radial, and ulnar dislocations are rare.

Question 58

A 30-year-old office worker presents with pain over the ulnar side of his wrist, exacerbated by gripping and lifting, particularly with the wrist in ulnar deviation. There is tenderness over the base of the 5th metacarpal and pisiform. What is the most likely diagnosis?

Explanation

Pain and tenderness localized to the base of the 5th metacarpal and pisiform, exacerbated by gripping and ulnar deviation, are classic signs of pisotriquetral osteoarthritis. This degenerative condition affects the articulation between the pisiform and triquetrum. While TFCC tears, hamate fractures, ECU tendinopathy, and LT ligament tears can cause ulnar-sided pain, the precise localization to the pisiform region points most strongly to pisotriquetral pathology.

Question 59

In a traumatic complete rupture of the ulnar collateral ligament of the thumb MCP joint without a bony avulsion, what is the most important anatomical factor that dictates the need for surgical repair?

Explanation

The presence of a Stener lesion is the most important anatomical factor dictating surgical repair for a complete UCL tear of the thumb. A Stener lesion occurs when the adductor aponeurosis displaces superficially and interposes between the torn ends of the UCL, preventing healing. Stress testing helps diagnose a complete tear, but the Stener lesion is the specific anatomical barrier to non-operative healing. Without surgical intervention, the joint will remain unstable. Other factors are important but secondary to the Stener lesion.

Question 60

Which type of fracture involving the distal radius is characterized by an intra-articular fracture with a dorsal rim fragment and dorsal displacement of the carpus?

Explanation

A dorsal Barton's fracture is an intra-articular fracture of the distal radius involving the dorsal rim, with the carpus and articular fragment displacing dorsally. This is a shear fracture. Colles' is extra-articular dorsal displacement. Smith's is volar displacement. Chauffeur's is a radial styloid fracture. Galeazzi is a radial shaft fracture with DRUJ dislocation.

Question 61

A 50-year-old male presents with chronic wrist pain. Radiographs reveal Scapholunate Advanced Collapse (SLAC). Which of the following carpal articulations is classically preserved and typically remains free of degenerative changes in the end stages of this condition?

Explanation

In a SLAC wrist, the radiolunate articulation is classically spared because the lunate remains concentrically congruent with the spherical lunate fossa of the radius. Degenerative changes predictably progress from the radial styloid to the scaphoid fossa, and ultimately to the capitolunate joint.

Question 62

A 38-year-old female presents with dorsal wrist pain. MRI confirms avascular necrosis of the lunate (Kienböck's disease). Radiographs demonstrate ulnar negative variance of 3mm and a structurally intact lunate with no carpal collapse (Lichtman Stage II). What is the most appropriate surgical management?

Explanation

Radial shortening osteotomy is the procedure of choice for early-stage Kienböck's disease (Lichtman I-IIIa) in patients with ulnar negative variance. It biomechanically unloads the radiolunate joint, which helps revascularize the lunate and halts progressive carpal collapse.

Question 63

A 62-year-old female with long-standing rheumatoid arthritis reports a sudden inability to actively flex the interphalangeal joint of her right thumb. Which of the following is the most likely etiology of her condition (Mannerfelt-Norman syndrome)?

Explanation

Mannerfelt-Norman syndrome specifically refers to the spontaneous rupture of the flexor pollicis longus (FPL) tendon in patients with rheumatoid arthritis. This attrition rupture occurs secondary to a bony spur located on the palmar aspect of the scaphoid.

Question 64

A 25-year-old industrial worker sustains a high-pressure paint injection injury to the volar tip of his index finger. The puncture wound is 1mm, with minimal swelling and mild pain. What is the most appropriate immediate management?

Explanation

High-pressure injection injuries are surgical emergencies associated with a high rate of amputation due to chemical necrosis and compartment syndrome. Despite a benign initial appearance, they mandate immediate open surgical debridement and extensive decompression in the operating room.

Question 65

Following a Zone II flexor tendon repair, early active mobilization protocols are commonly initiated. The predominant segmental vascular supply to the flexor tendons within this zone, which is critical for healing, is supplied primarily by which of the following structures?

Explanation

In Zone II, the flexor tendons receive critical segmental intrinsic blood supply via the vincula brevia and longa, which arise from the transverse branches of the digital arteries. Preservation of the vincula during surgery is essential to prevent tendon necrosis.

Question 66

A 24-year-old male presents with a scaphoid proximal pole fracture non-union. Which of the following best describes the predominant arterial supply to the proximal pole of the scaphoid?

Explanation

The scaphoid receives 70-80% of its blood supply from branches of the radial artery entering via the dorsal ridge distally and flowing retrograde. This retrograde blood supply puts the proximal pole at high risk for avascular necrosis following fractures.

Question 67

During a zone 2 flexor tendon repair, preservation of which pulleys is considered most critical to prevent bowstringing and maintain finger biomechanics?

Explanation

The A2 (located at the proximal phalanx) and A4 (located at the middle phalanx) pulleys are the most critical biomechanically. Disruption leads to bowstringing, loss of excursion, and decreased flexion power.

Question 68

In Dupuytren's contracture, the spiral cord is responsible for proximal interphalangeal (PIP) joint contracture. It typically displaces the neurovascular bundle in which direction?

Explanation

The spiral cord displaces the neurovascular bundle volarly (superficially) and centrally (towards the midline). This abnormal anatomy places the nerve at high risk of transection during fasciectomy.

Question 69

According to Mayfield's progressive perilunar instability, what is the final stage (Stage IV) of the sequence?

Explanation

Mayfield's stages describe a predictable pattern of ligamentous injury around the lunate. Stage I is scapholunate dissociation, Stage II includes capitate dislocation, Stage III is perilunate dislocation, and Stage IV is a volar lunate dislocation.

Question 70

A 65-year-old female with long-standing rheumatoid arthritis suddenly loses the ability to actively flex her thumb interphalangeal joint. What is the most likely etiology?

Explanation

Mannerfelt syndrome refers to the attrition rupture of the flexor pollicis longus (FPL) tendon in rheumatoid arthritis. This typically occurs as it rubs over a bony spur located on the volar scaphoid.

Question 71

In the natural history of Scapholunate Advanced Collapse (SLAC), which articulation is typically spared from degenerative arthritic changes?

Explanation

In SLAC wrist, the radiolunate joint is typically spared from osteoarthritis due to its concentric, spherical articulation which maintains normal contact stresses despite carpal collapse. This preservation allows for radiolunate-sparing salvage procedures like a four-corner fusion.

Question 72

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

Explanation

Kanavel's signs include a flexed posture of the digit (not extension), fusiform swelling, tenderness along the tendon sheath, and severe pain with passive extension. These signs mandate urgent surgical decompression and washout.

Question 73

A 32-year-old manual laborer is diagnosed with Kienbock's disease. Radiographs show lunate sclerosis, fragmentation, and carpal collapse, with fixed scaphoid rotation but no osteoarthritis. According to the Lichtman classification, what stage is this?

Explanation

Lichtman Stage IIIA involves lunate collapse without fixed scaphoid rotation or carpal height loss. Stage IIIB features lunate collapse with fixed scaphoid flexion and loss of carpal height, while Stage IV adds radiocarpal or midcarpal arthritis.

Question 74

A 45-year-old female treated non-operatively for a minimally displaced distal radius fracture presents 6 weeks later with a sudden inability to actively extend her thumb interphalangeal joint. What is the most appropriate management?

Explanation

EPL rupture is a known complication of nondisplaced or minimally displaced distal radius fractures due to attrition and ischemia. Because the tendon ends are typically frayed and retracted, EIP to EPL transfer is the preferred surgical treatment.

Question 75

In a Bennett's fracture, what muscle is primarily responsible for the proximal and dorsal displacement of the first metacarpal shaft?

Explanation

The volar ulnar beak fragment remains tethered to the trapezium by the anterior oblique ligament. The metacarpal shaft is pulled proximally and dorsally by the Abductor Pollicis Longus (APL), with adductor pollicis contributing to the adduction deformity.

Question 76

A cyclist presents with numbness in the volar aspect of the small finger and ulnar half of the ring finger, along with intrinsic muscle weakness. Sensation on the dorsoulnar aspect of the hand is preserved. Where is the most likely site of ulnar nerve compression?

Explanation

Compression in Guyon's canal spares the dorsal ulnar cutaneous nerve, which branches off proximally to the wrist. Zone 1 compression causes mixed motor and sensory deficits, whereas Zone 2 is purely motor and Zone 3 is purely sensory.

Question 77

A 55-year-old male presents with advanced SLAC (Scapholunate Advanced Collapse) wrist. Radiographs reveal degenerative changes at the radioscaphoid and capitolunate joints, while the radiolunate joint is entirely preserved. According to the SLAC staging system, which stage does this represent and what is the most appropriate definitive surgical management?

Explanation

Stage III SLAC wrist involves arthritic changes at the radioscaphoid and capitolunate joints with a preserved radiolunate joint. Scaphoid excision with four-corner fusion or proximal row carpectomy are standard treatments for Stage III, provided the capitate head is preserved for PRC.

Question 78

During a flexor tendon repair in Zone II of the hand, maintaining the integrity of the pulley system is critical to prevent bowstringing of the tendon. Which two pulleys are the most mechanically essential and should be preserved or reconstructed?

Explanation

The A2 and A4 pulleys arise from the proximal and middle phalanges, respectively, and are mechanically the most important for preventing bowstringing. Their preservation or reconstruction is vital during Zone II flexor tendon repairs.

Question 79

A 42-year-old female sustained a nondisplaced distal radius fracture treated conservatively in a cast. Six weeks later, she suddenly loses the ability to actively extend her thumb interphalangeal joint. What is the preferred surgical management for this complication?

Explanation

This patient has an EPL rupture due to ischemic attrition at the watershed area or friction over a bony spike following a distal radius fracture. Primary repair is usually impossible due to tendon retraction and degeneration, making an EIP to EPL tendon transfer the gold standard treatment.

Question 80

According to Mayfield's progressive perilunate instability classification, which of the following represents the correct sequential sequence of ligamentous failure ending in a lunate dislocation?

Explanation

Mayfield's stages of perilunate instability occur in a distinct sequence: Stage I (Scapholunate), Stage II (Capitolunate), Stage III (Lunotriquetral), and Stage IV (Lunate dislocation, failing the dorsal radiocarpal ligaments and displacing volarly).

Question 81

A 30-year-old cyclist presents with weakness in thumb adduction, finger abduction, and finger adduction. Sensation over the entire hand, including the small finger, is completely normal. Where is the most likely site of nerve compression?

Explanation

Guyon's canal Zone 2 contains only the deep motor branch of the ulnar nerve. Compression here causes isolated weakness of ulnar-innervated intrinsic muscles with perfectly spared sensation.

Question 82

A 22-year-old male presents with a proximal pole scaphoid nonunion diagnosed 18 months after a fall. MRI confirms avascular necrosis (AVN) of the proximal pole. Which of the following surgical options offers the highest rate of union?

Explanation

For a proximal pole scaphoid nonunion with AVN, vascularized bone grafting (such as the 1,2 ICSRA or medial femoral condyle graft) is required to restore blood supply and maximize union rates. Non-vascularized grafts have highly unacceptably high failure rates in the presence of established AVN.

Question 83

Which of the following is considered an absolute indication for replantation following an amputation?

Explanation

Absolute indications for replantation include amputations of the thumb, multiple digits, any amputation in a child, and amputations through the palm or wrist. Single digit amputations in Zone II for adults are generally relative contraindications depending on patient factors.

Question 84

A 29-year-old male presents with dorsal wrist pain. X-rays reveal Lichtman Stage IIIA Kienbock's disease with a negative ulnar variance of 3mm. What is the most appropriate joint-leveling procedure to unload the lunate?

Explanation

In early stages of Kienbock's disease (Stages I-IIIA) with negative ulnar variance, joint-leveling procedures are indicated to unload the lunate. Radial shortening osteotomy is the gold standard as it is technically easier and has lower nonunion rates than ulnar lengthening.

Question 85

A patient with a high radial nerve palsy requires tendon transfers to restore wrist, finger, and thumb extension. The standard Boyes transfer is planned. Which muscle is typically transferred to the Extensor Carpi Radialis Brevis (ECRB) to restore wrist extension?

Explanation

In classic tendon transfers for radial nerve palsy, the Pronator Teres (PT) is transferred to the ECRB to restore strong wrist extension. The FCR or FCU is typically used for finger extension (to EDC), and PL is used for thumb extension (to EPL).

Question 86

A 34-year-old diabetic patient presents with a swollen, painful index finger 3 days after a minor puncture wound. Of the four classic Kanavel signs for suppurative flexor tenosynovitis, which is considered the earliest and most reliable indicator of infection?

Explanation

Kanavel's four signs include fusiform swelling, flexed posture, tenderness over the sheath, and pain on passive extension. Pain on passive extension is classically considered the earliest, most sensitive, and most reliable sign of suppurative flexor tenosynovitis.

Question 87

A 62-year-old female presents with severe pain at the base of the thumb. Radiographs demonstrate Eaton-Littler Stage IV basal joint arthritis. What radiographic finding distinguishes Stage IV from Stage III?

Explanation

Eaton-Littler staging evaluates thumb carpometacarpal arthritis. Stage III is defined by advanced CMC arthritis with large osteophytes (>2mm), while Stage IV is defined by the additional arthritic involvement of the scaphotrapezial-trapezoid (STT) joint.

Question 88

A 21-year-old rugby player sustained a "jersey finger" injury. Exploration reveals a Type I Leddy-Packer avulsion of the flexor digitorum profundus (FDP). What is the defining characteristic of this injury and its required timing for repair?

Explanation

Type I jersey finger involves the FDP retracting all the way into the palm, which ruptures both the short and long vincula. Because the tendon loses its blood supply, it must be repaired early (within 7-10 days) before it undergoes irreversible necrosis and contracture.

Question 89

A patient presents with a suspected closed central slip rupture of the extensor mechanism at the PIP joint. During Elson's test, the PIP joint is flexed to 90 degrees and the patient is asked to actively extend against resistance. What finding indicates a complete rupture of the central slip?

Explanation

In Elson's test, if the central slip is ruptured, the extensor effort is transmitted entirely through the lateral bands, which subluxate volarly at the PIP joint but forcefully pull the DIP joint into rigid extension. If intact, the DIP remains floppy.

Question 90

A 28-year-old male presents with a "fight bite" over the third metacarpophalangeal joint after striking another person in the mouth. Which organism is uniquely associated with this specific injury mechanism, and what is the empiric antibiotic of choice?

Explanation

Human bites ("fight bites") carry a high risk of deep infection. Eikenella corrodens is the classic organism uniquely associated with human oral flora. The empiric treatment of choice is surgical washout coupled with Amoxicillin-clavulanate (Augmentin).

Question 91

A 45-year-old female presents with an inability to make an "OK" sign with her thumb and index finger. She has no sensory deficits. Examination reveals weakness in flexing the thumb interphalangeal joint and the index finger distal interphalangeal joint. What is the diagnosis?

Explanation

AIN syndrome is a pure motor neuropathy affecting the flexor pollicis longus (FPL), the flexor digitorum profundus (FDP) to the index/middle fingers, and the pronator quadratus. This classically presents as an inability to form the "OK" sign, with entirely normal sensation.

Question 92

A patient with long-standing rheumatoid arthritis presents with a sudden inability to flex their thumb interphalangeal joint. This is known as a Mannerfelt-Norman syndrome. What is the pathoanatomic cause of this specific tendon rupture?

Explanation

Mannerfelt-Norman syndrome refers to the spontaneous rupture of the flexor pollicis longus (FPL) tendon in rheumatoid patients. It is caused by attritional wear over a bony prominence, most commonly a volar osteophyte on the scaphoid.

Question 93

When performing a carpal tunnel release, the surgeon must be mindful of the recurrent motor branch of the median nerve. Which anatomical variation of the recurrent motor branch is the most common?

Explanation

The extraligamentous variation is the most common path of the recurrent motor branch of the median nerve, occurring in roughly 50% of people. It branches distal to the transverse carpal ligament and recurrently enters the thenar musculature.

Question 94

Fasciotomy for compartment syndrome of the hand requires thorough decompression. How many distinct fascial compartments are recognized in the hand?

Explanation

There are 10 recognized compartments in the hand. These consist of four dorsal interosseous, three volar interosseous, the thenar, the hypothenar, and the adductor pollicis compartments.

Question 95

In Dupuytren's disease, different fascial cords are responsible for specific joint contractures and anatomical displacements. Which cord is primarily responsible for proximal interphalangeal (PIP) joint contracture and causes central/volar displacement of the neurovascular bundle?

Explanation

The spiral cord contributes to PIP joint contracture and uniquely displaces the neurovascular bundle centrally and volarly, placing it at high risk of iatrogenic injury during surgical excision.

Question 96

A 32-year-old male presents with a rigid, isolated volar dislocation of the distal radioulnar joint (DRUJ) following a hyperpronation injury. Attempted closed reduction is unsuccessful. What anatomical structure is most commonly responsible for blocking the closed reduction of a volar DRUJ dislocation?

Explanation

In a volar dislocation of the DRUJ, the ulnar head displaces volarly. The pronator quadratus is frequently the structure that entraps the ulnar head, acting as a soft tissue interposition that blocks closed reduction.

Question 97

A 32-year-old male presents with chronic dorsal wrist pain and decreased grip strength. Radiographs demonstrate sclerosis and early collapse of the lunate, with a negative ulnar variance of 3mm. There is no evidence of radiocarpal or midcarpal arthritis. Which of the following is the most appropriate surgical management?

Explanation

This patient has Stage IIIA Kienbock's disease with negative ulnar variance. A joint-leveling procedure, such as a radial shortening osteotomy, offloads the radiolunate joint and is the treatment of choice before the onset of degenerative arthritis.

Question 98

A 55-year-old manual laborer presents with progressively worsening radial-sided wrist pain. Radiographs reveal narrowing of the radioscaphoid joint and capitolunate joint, but the radiolunate joint is preserved. Scapholunate dissociation is noted. What is the most appropriate definitive surgical intervention?

Explanation

This describes Stage III Scapholunate Advanced Collapse (SLAC) wrist, characterized by radioscaphoid and capitolunate arthritis with a preserved radiolunate joint. Proximal row carpectomy is contraindicated due to capitate involvement, making scaphoid excision and four-corner fusion the most appropriate treatment.

Question 99

A 22-year-old rugby player presents with an inability to actively flex the distal interphalangeal (DIP) joint of his ring finger after grabbing an opponent's jersey. Examination reveals tenderness in the palm, and ultrasound confirms the flexor digitorum profundus (FDP) tendon has retracted to the level of the lumbrical origin. Which Leddy-Packer type is this, and what is the required timeframe for primary repair?

Explanation

A Type I Leddy-Packer injury involves FDP retraction into the palm, disrupting all vincular blood supply. Primary repair must be performed within 7 to 10 days to prevent tendon necrosis and irreversible retraction.

Question 100

A 45-year-old female presents with sudden inability to actively extend the interphalangeal joint of her thumb. Six weeks prior, she sustained a nondisplaced distal radius fracture treated in a cast. What is the most reliable surgical option to restore thumb extension?

Explanation

Delayed EPL rupture after a nondisplaced distal radius fracture is due to vascular ischemia or mechanical attrition in Lister's tubercle. Primary repair is rarely possible due to tendon retraction and degeneration, making an EIP to EPL tendon transfer the gold standard treatment.

AAOS & ABOS Upper Extremity MCQs (Set 4): Shoulder, Elbow, Wrist, Hand & Nerve Review | 2025-2026 Boards

Orthopedic Hand & Wrist MCQs: FRCS Board Prep & Practice Exam Engine

Key Takeaway

Orthopedic Hand & Wrist MCQs: FRCS Board Prep & Practice Exam Engine

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