Marinacci Communication With Recovery of the Thumb, Finger, and Wrist Flexion After a High Median Nerve Injury: A Case Report and Review of Literature

The Marinacci communication (MC) contains fibers from the ulnar to the median nerve in the forearm in a proximal to distal fashion. This rare ulnar-to-median nerve anomalous communication has mainly been reported as an incidental finding. In the case presented here, this anatomical variation led to rapid recovery of the thumb, finger, and wrist flexion following a high above elbow complete median nerve injury. A 17-year-old female was involved in an all-terrain vehicle rollover accident and had her right elbow crushed. She presented with no motor or sensory function in the forearm and hand, with a weak monophasic radial artery signal and no palpable pulse. She underwent surgery and was treated with 12 cm interposition cable sural nerve grafting. Although recovery after a high median nerve injury is often prolonged and incomplete, the MC resulted in the recovery of sensation and motor function through muscles typically innervated by the median nerve, following a complete high median nerve injury. In the presence of anomalous recovery following median nerve injury or unusual electrophysiological findings, an MC should be considered as a cause.