Iatrogenic median and ulnar nerve injuries during carpal tunnel release: clinical, electrodiagnostic, and ultrasound features in 12 patients. Patient series.

Abstract

Nerve injuries during carpal tunnel release (CTR) are rare. Electrodiagnostic (EDX) and ultrasound (US) studies may be helpful in evaluating iatrogenic nerve injuries during CTR. Nine patients sustained a median nerve injury, and 3 patients experienced ulnar nerve damage. Decreased sensation occurred in 11 patients, and dysesthesia occurred in 1 patient. Abductor pollicis brevis (APB) weakness occurred in all patients with median nerve injury. Of the 9 patients with median nerve injury, the compound muscle action potentials (CMAPs) of the APB and sensory nerve action potentials (SNAPs) of the 2nd or 3rd digit were not recordable in 6 and 5 patients, respectively. Of the 3 patients sustaining ulnar nerve injuries, the CMAPs of the abductor digiti minimi (ADM) and SNAPs of the 5th digit were not recordable in 1 patient; 2 patients showed prolonged latency and decreased amplitude of CMAPs/SNAPs. US studies of 8 patients with a median nerve injury showed a neuroma within the carpal tunnel. One patient underwent surgical repair urgently, and 6 did so after variable intervals. Surgeons should be cognizant of nerve injuries during CTR. EDX and US studies are useful in evaluating iatrogenic nerve injuries during CTR.