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

Objective: To compare clinical, electrophysiologic, and computed tomography (CT) imaging correlates of reinnervation in replanted limbs. Design: Patients were assessed between 8 and 194 months after replantation of completely severed hands. Setting: University hospital, departments for neurology and for plastic and reconstructive surgery. Participants: Thirteen patients, 10 with total and 3 with subtotal type V a mputation, whose hands had been reattached. Interventions: Clinical assessment of function of hand and finger muscles; electromyographic tests of sensory nerve action potentials (SNAPs) of media n, ulnar, and radial nerves; and compound motor action potentials (CMAPs) o f abductor pollicis brevis, first dorsal interosseus, and abductor digiti m inimi muscles. CT assessment of motor unit action potentials. Measurements of both replanted and normal hands. Main Outcome Measures: Medical Research Council scale of force; sensory fun ctions of anatomic areas of nerves; SNAP and CMAP amplitudes; CT area, mean absorption, standard deviation (SD) from mean absorption, and root mean sq uare SD of absorption. Results: Correlates of reinnervation were evidenced by all methods, except by surface recordings of SNAPs, which could not be elicited even in hands w ith good sensory function. CMAP amplitudes were the electrophysiologic para meter that correlated best with the clinical restoration. Of the CT measure s, the cross-sectional area was the most useful parameter for the detection of denervation, but no CT parameter was sufficiently sensitive to detect r einnervation. In cases with good functional recovery, CMAP amplitudes were superior to clinical rating in showing incomplete reinnervation. Conclusion: The combination of clinical and electrophysiologic methods supp lied sufficient data for a reliable evaluation of reinnervation. Usually, C T parameters did not add useful information.