UPPER-EXTREMITY PERIPHERAL NERVE INJURIES
Data from three Louisiana State University Health Sciences Center (LSUHSC) publications were summarized for median, radial, and ulnar nerve injuries.
Lesion types, repair techniques, and outcomes were compared for 1837 upper-extremity nerve lesions.
Sharp laceration injury repair outcomes at various levels for median and radial nerves were equally good (91% each) and better than those for the ulnar nerve (73%). Secondary suture and graft repair outcomes were better for the median nerve (78% and 68%, respectively) than for the radial nerve (69% and 67%, respectively) and ulnar nerve (69% and 56%, respectively). In-continuity lesions with positive nerve action potentials during intraoperative testing underwent neurolysis with good results for the median (97%), radial (98%), and ulnar nerves (94%). For radial, median, and ulnar nerve in-continuity lesions with negative intraoperative nerve action potentials, good results occurred after suture repair in 88%, 86%, and 75% and after graft repair in 86%, 75% and 56%, respectively.
Good outcomes after median and radial nerve repairs are attributable to the following factors: the median nerve's innervation of proximal, large finger, and thumb flexors; and the radial nerve's similar innervation of proximal muscles that do not perform delicate movements. This is contrary to the ulnar nerve's major nerve supply to the distal fine intrinsic hand muscles, which require more extensive innervation. The radial nerve also has a motor fiber predominance, reducing cross-motor/sensory reinnervation, and radial nerve-innervated muscles perform similar functions, decreasing the chance of innervation of muscles with opposite functions.