COMPLICATIONS OF INJURY
Complications of nerve injuries
Missed nerve injuries
Partial nerve lacerations may be missed because their presentation is not a full blown picture of anesthesia or paralysis. Such injuries are best treated by a primary repair (prtnerve2.htm). Delayed or secondary exploration may result in additional nerve injury, because it may be impossible to distinguish between healing tissue, scar tissue, and nerve tissue which either functioning or has the capacity to heal. Late exploration of a healed partial nerve injury usually reveals an amorphous neuroma in continuity, and the only practical option may be to completely divide the nerve, excise the entire neuroma and reconstruct the entire nerve with nerve grafts. This may be difficult to justify when the patient has either retained or recovered partial nerve functionCommon complications of nerve injuries in the hand as elsewhere include tender neuroma, paralysis, and incomplete sensory recovery. In addition, upper extremity nerve injuries usually produce some degree of cold intolerance, and are a common trigger for complex regional pain syndrome. Dysesthesia and disuse of the hand may occur, and are best treated with an aggressive desensitization and sensory reeducation program under the supervision of a hand therapist. Median nerve injuries result in a greater loss of hand function than ulnar nerve injuries because the critical contact areas of the hand are affected.
Motor branch injuries are most often missed following small entry deeply penetrating wounds. The ulnar motor branch in the palm, the median motor branch in the palm, and the posterior interosseous nerve in the forearm may be injured without producing sensory loss and may be missed by casual survey.
Complications of the treatment
of nerve injuries include failure due to repair under tension,
repair within a poorly vascularized soft tissue bed, and contractures
due to splinting to relieve tension on a tight repair. Patients who have
a wide zone of anesthesia must be instructed on self protection from cuts
and burns. Contractures from paralysis are avoidable, but must be anticipated
and prevented with splinting: untreated, median nerve palsy will result
in a first web space contracture, and ulnar nerve palsy will result
in proximal interphalangeal joint contractures of the ring and small fingers.