Second Toe Extensor Digitorum Brevis Provides a Simultaneous Abductorplasty to Free Vascularized Metatarsophalangeal Joint Transfer for Posttraumatic Thumb Composite Metacarpophalangeal Joint Defect

Abstract

For functional reconstruction of a thumb metacarpophalangeal joint defect with loss of opposition, we need to address both joint mobility and thumb opposition. Free vascularized second toe joint transplantation provides joint replacement, as well as extensor and flexor tendons for apprehensile thumb restoration. Furthermore, the extensor digitorum brevis (EDB) allows a simultaneous abductorplasty for the reconstruction of traumatized abductor pollicis brevis. Seven patients underwent one-stage vascularized second toe metatarsophalangeal joint transfers to thumb metacarpophalangeal joints with the aim of reconstructing posttraumatic composite soft tissue, joints, and extrinsics or intrinsics tendon loss or both. The EDB was used for restoring abduction function, with the method of repairing to either remaining abductor pollicis brevis or palmaris longus tendon. All seven toe joints survived. Tenolysis and web-space contracture release was performed in three patients. One patient underwent corrective osteotomy for radial deviation. Patients were followed up for an average of 47 months. The average active arc of motion of the joints was 27.10 (range, 0-400). Angle of first ray separation or circumduction presented 63.3% or 55.3% compared with the uninjured side. Opposition of the thumb was assessed with the scoring system described by Kapandji, and the average score was 6.85. Simultaneous second toe EDB abductorplasty and vascularized second toe metatarsophalangeal joint transfer can provide a one-stage thumb MPJ composite defect reconstruction with apprehensile function.