Isolated injury to the median nerve above the elbow. A review of thirteen cases.

Isolated median-nerve injuries above the elbow are uncommon and are usually associated with injury to the brachial artery. The typical findings in the thirteen patients studied were loss of sensation in the distribution of the nerve and atrophy of the forearm flexors and thenar muscles in all patients. The only consistent motor loss was lack of flexion of the interphalangeal joints of the thumb and index finger. Inability to rotate the thumb occurred in five of the thirteen patients. Forearm pronation was weakened but was never completely lost. Suture of the brachial artery restored the radial pulse in all patients but not always immediately. Both primary and secondary nerve suture resulted in an excellent return of protective sensation. In two young patients with primary nerve repair sudomotor activity returned twenty-three and twenty-six months, respectively, after injury. Action of the digital flexors returned clinically and electromyographically in all patients. In four patients an abnormal grasp developed and they had to relearn thumb and index finger flexion. During the time required for nerve regeneration, burns of the hand were a significant complication for five of the thirteen patients. Loss of thumb rotation, which occurred in five of the thirteen patients, appeared to be the most serious disability. Nerve suture was effective in restoring this function in only one of the five patients. Tendon transfer to restore thumb rotation was performed in the remaining four patients. This procedure was reserved for patients who have reinnervation of the forearm muscles, a return of protective sensation to the hand, and joints that have been kept supple by exercising and splinting.