Evaluation of clinical, electrophysiologic, and computed tomographic parameters in replanted hands

To compare clinical, electrophysiologic, and computed tomography (CT) imaging correlates of reinnervation in replanted limbs.

Patients were assessed between 8 and 194 months after replantation of completely severed hands.

University hospital, departments for neurology and for plastic and reconstructive surgery.

Thirteen patients, 10 with total and 3 with subtotal type V amputation, whose hands had been reattached.

Clinical assessment of function of hand and finger muscles; electromyographic tests of sensory nerve action potentials (SNAPs) of median, ulnar, and radial nerves; and compound motor action potentials (CMAPs) of abductor pollicis brevis, first dorsal interosseus, and abductor digiti minimi muscles. CT assessment of motor unit action potentials. Measurements of both replanted and normal hands.

Medical Research Council scale of force; sensory functions of anatomic areas of nerves; SNAP and CMAP amplitudes; CT area, mean absorption, standard deviation (SD) from mean absorption, and root mean square SD of absorption.

Correlates of reinnervation were evidenced by all methods, except by surface recordings of SNAPs, which could not be elicited even in hands with good sensory function. CMAP amplitudes were the electrophysiologic parameter that correlated best with the clinical restoration. Of the CT measures, the cross-sectional area was the most useful parameter for the detection of denervation, but no CT parameter was sufficiently sensitive to detect reinnervation. In cases with good functional recovery, CMAP amplitudes were superior to clinical rating in showing incomplete reinnervation.

The combination of clinical and electrophysiologic methods supplied sufficient data for a reliable evaluation of reinnervation. Usually, CT parameters did not add useful information.