Delayed Repair of Recurrent Motor Branch Injury after Carpal Tunnel Release.

Iatrogenic injury to the recurrent motor branch of the median nerve is an uncommon but severe complication following carpal tunnel release. Surgeons should be aware of the anatomical variations of this branch, particularly with the advent of smaller incisions and endoscopic techniques. Here, we present the case of a 60-year-old woman whose recurrent motor branch injury was not identified until 2 years following her index procedure. She underwent a successful primary repair 25 months after her initial injury, with notable improvements in thumb function, strength, and return of thenar muscle bulk beginning 2 months after surgery and continuing through last follow-up at 7 months. Our patient's outcome suggests that repair of a severed recurrent motor branch remains a viable option 2 years after initial injury and that functional improvement and thenar muscle reinnervation can occur even after considerable time has elapsed.