ABPS Hand Surgery & Upper Extremity Reconstruction 1 — Questions and Answers
Question 1: Which nerve provides sensation to the palmar surface of the thumb, index finger, middle finger, and radial half of the ring finger?
- Ulnar nerve
- Median nerve (Correct answer)
- Radial nerve
- Musculocutaneous nerve
Correct answer: Median nerve
The median nerve supplies palmar sensation to the thumb, index, middle, and radial half of the ring finger via its digital branches.
Question 2: In carpal tunnel syndrome, which thenar muscle most commonly shows atrophy due to median nerve compression?
- Flexor pollicis brevis (deep head)
- Adductor pollicis
- Abductor pollicis brevis (Correct answer)
- First dorsal interosseous
Correct answer: Abductor pollicis brevis
Abductor pollicis brevis is exclusively innervated by the recurrent branch of the median nerve and is the earliest and most prominent muscle to atrophy in CTS.
Question 3: Verdan's Zone II of flexor tendon injuries, sometimes called 'no man's land,' is bounded by which anatomical landmarks?
- Wrist crease to the proximal palmar crease
- A1 pulley to the FDS insertion at the middle phalanx (Correct answer)
- DIP joint to the fingertip
- Carpal tunnel entrance to the lumbrical origin
Correct answer: A1 pulley to the FDS insertion at the middle phalanx
Zone II extends from the A1 pulley to the flexor digitorum superficialis insertion, where both FDS and FDP tendons run within a tight fibro-osseous sheath, making repair technically challenging.
Question 4: The Moberg advancement flap used for thumb tip reconstruction is based on which vascular pedicle?
- Posterior interosseous artery perforators
- Bilateral neurovascular bundles of the thumb (Correct answer)
- First dorsal metacarpal artery
- Radial artery superficial palmar branch
Correct answer: Bilateral neurovascular bundles of the thumb
The Moberg flap is a volar advancement flap based on both digital neurovascular bundles of the thumb, providing sensate coverage of the thumb tip.
Question 5: What is the initial treatment of choice for a closed mallet finger injury without significant volar subluxation of the distal phalanx?
- ORIF with K-wire fixation
- Continuous DIP joint extension splinting for 6–8 weeks (Correct answer)
- Buddy taping to the adjacent finger
- Immediate primary extensor tendon repair
Correct answer: Continuous DIP joint extension splinting for 6–8 weeks
Closed mallet finger without volar subluxation is managed conservatively with continuous DIP extension splinting for 6–8 weeks, which reliably restores extensor continuity.
Question 6: The Allen test is performed to assess patency of which vascular structures before hand surgery or arterial line placement?
- Digital flexor tendons
- Radial and ulnar arteries supplying the palmar arch (Correct answer)
- Carpal tunnel contents
- Intrinsic hand muscle vascularity
Correct answer: Radial and ulnar arteries supplying the palmar arch
The Allen test compresses both the radial and ulnar arteries simultaneously, then releases each individually to confirm dual arterial supply to the hand through the palmar arch.
Question 7: Which Verdan zone of flexor tendon injury is located within the carpal tunnel?
- Zone I
- Zone II
- Zone III
- Zone IV (Correct answer)
Correct answer: Zone IV
Zone IV corresponds to the carpal tunnel region where the flexor tendons pass beneath the flexor retinaculum alongside the median nerve.
ABPS Hand Surgery & Upper Extremity Reconstruction 1
Which nerve provides sensation to the palmar surface of the thumb, index finger, middle finger, and radial half of the ring finger?