Novel Surgical Procedure for Half Palmaris Longus Transfer during Opponensplasty of the Thumb for Patients with Carpal Tunnel Syndrome: A Technical Note.

Thumb opposition is an essential movement for daily use of the hand, including precise pinching/grasping and fine and complicated hand movement. Although studies have reported use of several donor tendons for opponensplasty, opponensplasty using the palmaris longus (i.e., Camitz opponensplasty) has been used in patients with loss of opposition function due to longstanding carpal tunnel syndrome. The procedure involves a simple, useful tendon transfer and does not cause functional deficits. To obtain enough length to transfer the tendon to the metacarpophalangeal joint of the thumb, the PL tendon should be obtained with the palmar aponeurosis. However, the palmar aponeurosis is not always available for opponensplasty, as it is occasionally thin and insufficient for elongation of the palmaris longus. An extended skin incision over the palm can cause painful scar formation and postoperative residual pain. This procedure restores the palmar abduction function of the thumb but not opposition function. In the present article, we describe a modification of Camitz opponensplasty that uses a half-split palmaris longus, which is long enough to anchor to the insertion of the adductor pollicis at the metacarpophalangeal joint of the thumb.