Nerve Transfer for Restoration of Ulnar Fingers Flexion Through Pronator Teres Motor Branch: A Cadaveric Feasibility Study

Purpose Injury to the ulnar nerve above the elbow or other conditions such as brachial plexus injury or cervical spinal cord injury can also affect the extrinsic finger flexors. Numerous techniques have been described to treat this problem, but no specific nerve transfer has been proposed. Methods Here, we describe the transfer of the motor branch of the pronator teres (PT) to reinnervate flexor digitorum profundi of the ulnar nerve. Eleven fresh frozen upper limbs were used. The anatomical characteristics of the branches to the flexor digitorum profundus and PT were recorded. Results In all cases, the superficial branch of the PT resulted as the longest between the two and, therefore, was used as a donor. It was passed under the flexor pronator muscles to reach the ulnar nerve. The recipient motor branch was dissected proximally, and a direct nerve suture was made between the two stumps. Conclusions In all specimens, a direct tension free neurorrhaphy was possible, located close to the target muscle. Clinical relevance This specific procedure can be suggested in cases where the hand is partially involved to allow patients to regain or strengthen fingers flexion. Direct clinical application should support and confirm this novel procedure.