Intrapalm nerve transfers to improve intrinsic hand function in isolated ulnar or median nerve injuries: illustrative...

Proximal ulnar and median nerve injuries with Sunderland grade IV or V disruptions often lead to incomplete recovery of intrinsic hand muscles despite partial sensory and extrinsic motor recovery. However, traditional nerve transfers provide inconsistent intrinsic reinnervation. Persistent intrinsic deficits impair fine motor skills, such as pinch and grasp strength, and may necessitate secondary interventions.

Four patients with complete, isolated proximal ulnar or median nerve injuries underwent intrapalm donor nerve transfers. Procedures included transfer of the opponens pollicis motor branch to the terminal division of the deep motor branch of the ulnar nerve and the abductor digiti quinti motor branch to the thenar branch of the median nerve. All patients showed functional improvements in pinch and grip strength postoperatively. None required secondary tendon transfers, and no donor site morbidity was observed. In 3 ulnar nerve cases, Froment's sign converted from positive to negative. In the median nerve case, visible thumb abduction was restored.

Intrapalm donor nerve transfers show effective options for restoring intrinsic hand function and improving fine motor skills in patients with isolated proximal ulnar or median nerve injuries. https://thejns.org/doi/10.3171/CASE25744.