Hand Surgery & Upper Extremity Reconstruction Flashcards

According to Seddon's nerve injury classification, which type involves disruption of axons with an intact endoneurium, allowing spontaneous recovery along the preserved neural tube?

Answer: Axonotmesis

In axonotmesis, the axon is disrupted but the endoneurium (and usually perineurium) remains intact, providing a conduit for axon regeneration at approximately 1 mm/day.

Radial nerve palsy complicating humeral shaft fractures most commonly results from injury at which anatomical location?

Answer: Radial (spiral) groove of the humerus

The radial nerve is most vulnerable in the spiral (radial) groove of the mid-humerus, where it is tethered and directly at risk from midshaft humeral fractures.

What is the gold standard technique for peripheral nerve repair when primary tension-free repair is not achievable?

Answer: Autologous nerve graft (sural nerve)

Autologous nerve grafting using the sural nerve remains the gold standard for bridging nerve gaps, providing a scaffold with intact Schwann cells and endoneurial tubes to guide axon regeneration.

Extensor tendon injuries in Zone VIII (musculotendinous junction) are technically challenging primarily because of which factor?

Answer: Proximal muscle belly retraction making suture purchase difficult

At the musculotendinous junction (Zone VIII), the proximal muscle belly retracts and the tissue is friable, making suture fixation technically difficult and increasing the risk of repair failure.

When a palmar flexor tendon is exposed without intact paratenon following trauma or infection, which coverage option is most appropriate to achieve durable wound closure?

Answer: Local or regional vascularized flap

Exposed tendons without paratenon cannot support skin graft take; vascularized flap coverage (local, regional, or free) provides the necessary blood supply for tendon gliding and long-term durability.

In cubital tunnel syndrome (ulnar nerve compression at the elbow), which muscle typically demonstrates the earliest clinical weakness?

Answer: First dorsal interosseous

The first dorsal interosseous is the most distal ulnar-innervated intrinsic muscle and is the first to show weakness and wasting in cubital tunnel syndrome, detectable clinically before other intrinsics.

What is the most appropriate initial management for a fingertip amputation with exposed bone in a child younger than 6 years of age?

Answer: Conservative wound management with moist dressings

Children under 6 years have exceptional regenerative capacity for fingertip regrowth; conservative moist wound care consistently produces functional, sensate fingertip regeneration without surgery.