Flexor pollicis brevis adductorplasty: an alternative method in ulnar nerve paralysis

Loss of pinch power associated with loss of coordinated movement of thumb and index fingers is the major disability in patients with ulnar nerve paralysis. Several tendon transfer methods utilizing different donor muscles have been used to restore adductor pollicis muscle function in ulnar nerve paralysis. In this paper, we discuss the transfer of flexor digitorum brevis muscle to the tendon of adductor pollicis muscle as an alternative method to restore key pinch in ulnar nerve paralysis. The technique was applied to 4 patients with ulnar nerve paralysis. Before clinical application, an anatomic study was carried out in 6 cadaver hands. In cadavers, radial and ulnar arteries were injected with latex and arterial pedicles of flexor pollicis brevis muscle were dissected under 4x magnification. Also, motor branches from the median nerve were shown at the entrance point to the muscle. In surgical practice, the superficial head of the muscle is detached from its insertion and the minor pedicle of the muscle is cut. Muscle is dissected proximally up to two thirds of its length. The dominant pedicle of the muscle originating from superficial palmar arcus is preserved, and the muscle is sutured to the tendon of the adductor pollicis muscle close to its insertion. Patients were evaluated in terms of key pinch strength preoperatively and at the postoperative sixth month using a pinch meter (Chattanooga Group, Inc). Key pinch strengths were recorded and expressed as percentage of the strength of the contralateral uninvolved hand. Mean key pinch strength of our patients was 29.7%.In conclusion, we believe in that flexor pollicis brevis adductorplasty may be an alternative method for restoration of adductor pollicis muscle function in ulnar nerve paralysis.