Immediate Thumb Opposition Following Extensor Indicis Proprius Opponensplasty Using the Wide-Awake Approach

Abstract

(ECU) was widely excised. The EIP tendon and muscle belly were identified and delivered through this proximal incision (Figure 1D). The distal part of the muscle belly was gently freed by blunt dissection and retracted proximally. A small incision was created over the flexor carpi ulnaris (FCU) tendon at a point 1 cm proximal from the pisiform bone. A wide subcutaneous tunnel, running from the dorsal ulnar incision to this small incision, was then created (Figure 1D). The EIP tendon was passed through this subcutaneous tunnel, over the ECU tendon, around the distal ulna (which served as a pulley) and brought out through the small incision in the area immediately proximal to the pisiform bone (Figure 1E). A small skin incision was subsequently made over the radial aspect of the MP joint of the thumb to expose the APB tendon and the distal portion of the atrophied muscle. A tendon retriever was passed beneath the fascia of the APB muscle, commencing at the point of the 'small skin incision' described immediately above, and running to the small skin incision in the area of the FCU tendon; the EIP tendon was pulled distally through the tunnel (Figure 1E). All skin incisions were closed, with the exception of a single incision in the area of the MP joint of the thumb before the transfer was inserted into the APB tendon. The tendon tension was slightly tight when the thumb was in full palmar abduction and the wrist in a neutral position. The EIP tendon was attached to the APB tendon using multiple, fine nonabsorbable woven sutures (Figure 1F). Tension correctness was verified via active palmar abduction of the thumb. Finally, the thumb incision was closed. Postoperative treatment The hand was immobilized in a thumb spica cast, which maintained the wrist in a neutral position and the thumb in full opposition for three weeks. A removable orthoplastic splint was subsequently applied for an addtional three weeks at which time rehabilitation was initiated , enabling active motion exercise without resistance. At six weeks, the splint was removed (except at night); however, all patients were advised to avoid using the hand for activities requiring application of >1 kg of force. The splint was finally discarded 12 weeks postsurgery, after which power-pinching was permitted. Evaluation Intraoperative findings and complications, including infection, hema-toma and rupture of the transferred tendon, were investigated through medical chart review. Extension deficit at the MP joint of the operated index finger was measured by the surgeon using a standard goniometer. Figure 1) Schematic illustration of the authors' extensor indicis proprius (EIP) opponensplasty procedure. A First, mini-open carpal tunnle release (CTR) is performed through a 1.5 cm to 2 cm incision (arrow). B A small portion of the extensor hood and EIP tendon is removed over the metacarpophalangeal (MP) joint of the index finger. C The hood is then meticulously repaired. The common extensor tendon is freed from the EIP through a small incision made over the mid-dorsum of the hand (arrowhead). D The EIP tendon and muscle belly are delivered through a curvilinear longitudinal skin incision over the dorsal ulnar aspect of the distal part of the forearm, and wide subcutaneous tunnel is developed, commencing at this incision. E A small incision is then made over the flexor carpi ulnaris (FCU) tendon. The EIP tendon is passed through the subcutaneous tunnel, over the extensor carpi ulnaris tendon, around the distal ulna (which serves as a pulley) and brought out through the 'small incision'. The abductor pollicis brevis (APB) tendon is exposed via a thenar incision made over the radial aspect of the MP joint of the thumb. A tendon retriever is passed beneath the fascia of the APB muscle, running from the thenar incision to the small skin incision in the area of the FCU tendon. F The EIP tendon is pulled distally over the FCU tendon through the subcutaneous tunnel and attached to the APB tendon. The tendon tension is slightly tight with the thumb in full palmar abduction and the wrist in a neutral position