Transfer of the flexor carpi radialis to the abductor pollicis brevis tendon for the restoration of tip-pinch in severe carpal tunnel syndrome

Abstract

In patients with severe thenar atrophy secondary to carpal tunnel syndrome, we hypothesize that following open carpal tunnel release, concomitant transfer of the abductor pollicis brevis (APB) origin to the flexor carpi radialis (FCR) tendon will lead to improved patient function restoring palmar abduction and thumb opposition. We evaluated 14 patients through questionnaires and seven patients through additional physical examination (thumb range of motion, ability to tip pinch, grip/pinch strength) for a mean follow-up of 2.8 years. All patients showed evidence of palmar abduction with 71% demonstrating the ability to oppose the thumb to the tip and base of the small finger. The transfer of the APB origin to the FCR tendon can restore thumb abduction and opposition for thenar paralysis secondary to severe carpal tunnel syndrome. Patients experience good functional outcomes with the majority experiencing restored thumb opposition.