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 5061
Topic: 7. Hand and Wrist
A patient sustains a flexor tendon laceration in "Zone II" of the hand. Which of the following best defines the anatomical boundaries of Zone II?
Correct Answer & Explanation
. From the proximal edge of the A1 pulley to the insertion of the FDS
Explanation
Zone II, often referred to as "no man's land," extends from the proximal edge of the A1 pulley to the insertion of the flexor digitorum superficialis (FDS). This zone is notorious for poor healing and adhesions due to the tightly confined fibro-osseous sheath.
Question 5062
Topic: Wrist & Carpus
A 28-year-old manual laborer presents with dorsal wrist pain. Radiographs reveal sclerosis and fragmentation of the lunate. Which of the following anatomic variants is most strongly associated with the pathogenesis of this condition?
Correct Answer & Explanation
. Negative ulnar variance
Explanation
Kienbock disease is characterized by avascular necrosis of the lunate. Negative ulnar variance is strongly associated with this condition, as it leads to increased radiolunate contact stresses and potential vascular compromise.
Question 5063
Topic: Nerve & Tendon
A 25-year-old rugby player injures his ring finger while grabbing an opponent's jersey. He cannot actively flex the distal interphalangeal (DIP) joint. If radiographs show a small bony avulsion retracted to the A4 pulley, what is the optimal timeframe for surgical repair to prevent fixed retraction and muscle belly shortening?
Correct Answer & Explanation
. Within 7 to 10 days
Explanation
A Jersey finger (FDP avulsion) that retracts into the palm compromises its blood supply from the vincula. It requires prompt surgical repair, ideally within 7 to 10 days, to prevent irreversible tendon retraction and necrosis.
Question 5064
Topic: 7. Hand and Wrist
In flexor tendon repairs within Zone II of the hand, the primary blood supply to the tendon proper is provided by the:
Correct Answer & Explanation
. Vincula brevia and vincula longa
Explanation
Within Zone II, flexor tendons receive their segmental blood supply dorsally through the vincula brevia and longa. While diffusion from synovial fluid also provides nutrition, the vincula represent the critical direct vascular supply.
Question 5065
Topic: 7. Hand and Wrist
During an open carpal tunnel release, care must be taken to completely divide the transverse carpal ligament while protecting adjacent structures. Which of the following tendons is located immediately outside the structural confines of the carpal tunnel?
Correct Answer & Explanation
. Flexor carpi radialis
Explanation
The carpal tunnel contains 9 tendons (4 FDS, 4 FDP, 1 FPL) and the median nerve. The flexor carpi radialis (FCR) is technically located outside the main carpal tunnel, as it runs within its own fascial sheath within the superficial split of the transverse carpal ligament.
Question 5066
Topic: Hand Trauma & Infection
Which of the following physical examination findings is NOT considered one of Kanavel's four classic cardinal signs of pyogenic flexor tenosynovitis?
Correct Answer & Explanation
. Erythema extending proximally beyond the wrist crease
Explanation
Kanavel's four cardinal signs of flexor tenosynovitis are: fusiform swelling, severe tenderness along the flexor sheath, excruciating pain with passive extension, and a semi-flexed resting posture. Proximal spreading erythema suggests cellulitis or lymphangitis, not a strict Kanavel sign.
Question 5067
Topic: 7. Hand and Wrist
A 24-year-old male sustains a proximal pole scaphoid fracture. The high risk of nonunion and avascular necrosis in this specific fracture pattern is best explained by the scaphoid's retrograde blood supply arising primarily from the:
Correct Answer & Explanation
. Dorsal carpal branch of the radial artery
Explanation
The primary blood supply to the scaphoid enters through its dorsal ridge via the dorsal carpal branch of the radial artery and flows in a retrograde fashion. Fractures at the proximal pole effectively sever this vascular supply, leading to a high rate of avascular necrosis.
Question 5068
Topic: 7. Hand and Wrist
A patient sustains a deep laceration to the volar aspect of the finger precisely at the distal interphalangeal (DIP) joint crease, resulting in an inability to actively flex the distal phalanx. This injury is located in which flexor tendon zone?
Correct Answer & Explanation
. Zone I
Explanation
Flexor tendon Zone I extends from the distal insertion of the flexor digitorum superficialis (FDS) on the middle phalanx to the insertion of the flexor digitorum profundus (FDP) on the distal phalanx. An injury at the DIP joint level isolates the FDP tendon and falls strictly into Zone I.
Question 5069
Topic: 7. Hand and Wrist
The primary blood supply to the proximal pole of the scaphoid enters the bone at which of the following anatomic locations?
Correct Answer & Explanation
. Dorsal ridge via the dorsal carpal branch of the radial artery
Explanation
The blood supply to the scaphoid is predominantly retrograde. Approximately 70-80% of the bone, including the entire proximal pole, is supplied by the dorsal carpal branch of the radial artery, which enters at the non-articular dorsal ridge and flows proximally. This retrograde blood supply explains the high rate of avascular necrosis (AVN) seen in proximal pole scaphoid fractures.
Question 5070
Topic: Nerve & Tendon
A 30-year-old carpenter sustains a zone II laceration of the flexor digitorum profundus (FDP). During repair, the surgeon chooses a 4-strand core suture over a 2-strand core suture. What is the primary biomechanical advantage of increasing the number of strands crossing the repair site in the context of an early active motion rehabilitation protocol?
Correct Answer & Explanation
. Increased gap resistance and tensile strength, withstanding the forces of early active motion
Explanation
In flexor tendon repairs, the tensile strength and gap resistance of the repair are directly proportional to the number of core suture strands crossing the repair site. A minimum of a 4-strand repair is required to safely withstand the forces generated during early active motion protocols without gapping. A 2-strand repair risks gapping or rupture with early active motion, while increasing strands beyond 4 may increase bulk and friction (work of flexion).
Question 5071
Topic: 7. Hand and Wrist
A 50-year-old female presents with persistent, unchanged numbness and tingling in her thumb, index, and middle fingers 6 months after an open carpal tunnel release. Postoperative EMG confirms severe, ongoing median neuropathy across the wrist. What is the most common cause of persistent carpal tunnel syndrome when symptoms have remained unchanged since surgery?
Correct Answer & Explanation
. Incomplete release of the transverse carpal ligament
Explanation
The most common cause of persistent carpal tunnel syndrome (symptoms that never resolved after surgery) is incomplete release of the transverse carpal ligament (typically the distal extent). Recurrent carpal tunnel syndrome (symptoms that improved but returned months to years later) is most commonly caused by perineural fibrosis or reconstitution of the ligament. Palmar cutaneous branch injury causes pain/numbness at the base of the palm, not in the median nerve digital distribution.
Question 5072
Topic: 7. Hand and Wrist
In hand surgery, the flexor tendon 'Zone II' (historically known as no man's land) is defined proximally by which of the following anatomical landmarks?
Correct Answer & Explanation
. The proximal edge of the A1 pulley
Explanation
Flexor tendon Zone II extends from the proximal edge of the A1 pulley to the insertion of the flexor digitorum superficialis (FDS) tendon. Because both the FDS and FDP tendons run tightly together within the fibro-osseous sheath here, repairs are prone to adhesions.
Question 5073
Topic: 7. Hand and Wrist
In the surgical treatment of Carpal Tunnel Syndrome, the transverse carpal ligament is incised. This ligament attaches ulnarly to the hook of the hamate and the pisiform, and radially to the scaphoid tuberosity and which other carpal bone?
Correct Answer & Explanation
. Trapezium
Explanation
The transverse carpal ligament (flexor retinaculum) attaches radially to the scaphoid tuberosity and the crest of the trapezium. Ulnarly, it attaches to the pisiform and the hook of the hamate.
Question 5074
Topic: Nerve & Tendon
A 22-year-old rugby player presents with an inability to actively flex the distal interphalangeal (DIP) joint of his right ring finger. MRI confirms an avulsion of the flexor digitorum profundus (FDP) tendon with complete retraction into the palm. What is the optimal time frame for surgical repair to prevent permanent muscle contracture and preserve the remaining blood supply?
Correct Answer & Explanation
. Within 7-10 days
Explanation
This is a Leddy-Packer Type I FDP avulsion (Jersey finger) where the tendon retracts into the palm, rupturing both the long and short vincula. Due to the severely compromised blood supply and rapid muscle contraction, repair should be performed within 7-10 days.
Question 5075
Topic: Nerve & Tendon
A 6-year-old boy sustains a completely displaced extension-type supracondylar fracture of the humerus. Radiographs demonstrate posteromedial displacement of the distal fragment. Which of the following peripheral nerves is at the highest risk of tethering or injury due to the sharply displaced proximal fragment?
Correct Answer & Explanation
. Radial nerve
Explanation
In an extension-type supracondylar humerus fracture with posteromedial displacement of the distal fragment, the proximal fragment naturally displaces anterolaterally. This anterolateral spike of bone places the radial nerve at the highest risk of injury.
Question 5076
Topic: 7. Hand and Wrist
A 24-year-old male falls onto an outstretched hand and sustains a non-displaced fracture of the scaphoid waist. A key factor in the high rate of nonunion for this fracture is the bone's retrograde blood supply. Which vessel serves as the primary source of intraosseous vascularity to the proximal pole of the scaphoid?
Correct Answer & Explanation
. Dorsal carpal branch of the radial artery
Explanation
The scaphoid receives 70-80% of its blood supply from the dorsal carpal branch of the radial artery. This vessel enters at the dorsal ridge near the scaphoid waist and supplies the proximal pole in a retrograde fashion, placing proximal fractures at a high risk of avascular necrosis.
Question 5077
Topic: 7. Hand and Wrist
A 45-year-old female presents 3 months after a distal radius fracture with persistent, burning pain, allodynia, swelling, and trophic changes in her hand, disproportionate to the initial injury. The limb appears cool and mottled. Nerve conduction studies are normal. This clinical picture is most consistent with Complex Regional Pain Syndrome Type 1 (CRPS-1). What is the most appropriate initial management strategy for this condition?
Correct Answer & Explanation
. A comprehensive physical and occupational therapy program focused on desensitization and active range of motion.
Explanation
The mainstay of CRPS-1 management is a multidisciplinary approach focusing on early, active rehabilitation. A comprehensive physical and occupational therapy program emphasizing desensitization, active range of motion, and gradual weight-bearing is crucial to break the pain-spasm cycle and restore function. Immobilization is contraindicated as it exacerbates the condition. Opioids are typically not the primary long-term solution due to risks of dependence and limited efficacy for neuropathic pain. While nerve blocks and medications (e.g., gabapentin, tricyclic antidepressants, bisphosphonates) may be used adjunctively, early, focused therapy is paramount. Surgical exploration is not indicated unless there's a specific, treatable nerve lesion, which is not suggested by normal nerve conduction studies. Corticosteroids may be used in acute phases but not typically as the primary long-term strategy.
Question 5078
Topic: 7. Hand and Wrist
A 28-year-old male presents with chronic wrist pain. He sustained a fall onto an outstretched hand 2 years ago. Radiographs demonstrate a scaphoid nonunion with radioscaphoid osteoarthritis, while the midcarpal joint is spared (SNAC Stage II). What is the most appropriate surgical treatment?
Correct Answer & Explanation
. Proximal row carpectomy or four-corner fusion
Explanation
In Scaphoid Nonunion Advanced Collapse (SNAC) Stage II, arthritis involves the radioscaphoid joint but spares the midcarpal and radiolunate joints. Appropriate salvage procedures include proximal row carpectomy or scaphoid excision with four-corner arthrodesis.
Question 5079
Topic: Hand Trauma & Infection
A 28-year-old carpenter presents with a swollen, erythematous, and exquisitely tender left index finger 2 days after a wood splinter puncture. The finger is held in slight flexion, and there is severe pain with passive extension. What is the most appropriate management?
Correct Answer & Explanation
. Incision and drainage in the operating room with systemic antibiotics
Explanation
The patient has Kanavel's four cardinal signs of acute suppurative flexor tenosynovitis (fusiform swelling, flexed posture, tenderness along the sheath, and pain on passive extension). This is a surgical emergency requiring prompt incision and drainage combined with systemic antibiotics to prevent tendon necrosis.
Question 5080
Topic: 7. Hand and Wrist
A 30-year-old carpenter sustains a volar laceration to his index finger at the level of the proximal phalanx, transecting both the FDS and FDP tendons. This injury corresponds to which of Verdan's flexor tendon zones?
Correct Answer & Explanation
. Zone II
Explanation
Zone II (historically known as 'no man's land') extends from the distal palmar crease (the proximal edge of the A1 pulley) to the insertion of the FDS on the middle phalanx. In this zone, both the FDS and FDP tendons are tightly enveloped within the same flexor sheath.
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