Opponensplasty With Abductor Pollicis Brevis Rerouting for Types II and IIIA Hypoplastic Thumbs.

ABSTRACT

PURPOSE: To evaluate the functional results after opponensplasty using an abductor pollicis brevis rerouting technique in type II and IIIA hypoplastic thumbs. METHODS: Eleven hypoplastic thumbs in nine children with type II and IIIA hypoplastic thumbs were treated with abductor pollicis brevis rerouting. The mean follow-up period was 70 months (range, 12-172 months). We assessed preoperative to postoperative changes in the angles of the first and second metacarpal axes and the longitudinal axis of the first metacarpal and proximal thumb phalanx as well as grip and pinch strengths. RESULTS: The mean angle of the first and second metacarpal axes showed a significant improvement to 64° (range, 47° to 89°), and the mean angle of the first metacarpal and proximal phalanx of the thumb showed a significant reduction to 8° (range, 1° to 21°) after surgery. The mean postoperative grip and pinch strengths were 77% (range, 63% to 106%) and 72.0% (range, 33% to 97%), respectively, relative to the unaffected side. CONCLUSIONS: Abductor pollicis brevis rerouting for type II and IIIA hypoplastic thumbs can produce joint stability and a strong pronation effect in addition to the opponens function. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic V.