Two-stage reconstruction for the hypoplastic thumb.

A 2-year-old boy with grade 3 hypoplastic thumb (Blauth's classification) underwent reconstruction in two stages. Stage 1 was an abductor digiti quinti musculocutaneous flap, first web space widening, and insertion of a silicone rod to prepare for a flexor pollicis longus transfer. Stage 2 (6 months later) was a vascularized second toe proximal interphalangeal joint transfer for carpometacarpal joint replacement, plus tendon transfers for thumb flexion, extension, and adduction. Three years following the procedures, the thumb had an open physis by x-ray film and was functioning well. Pollicization is the traditional procedure for this degree of thumb hypoplasia, but the two-stage reconstruction is an alternative for patients in cultures where the presence of five fingers is important.