Microsurgical reconstruction of the hypoplastic thumb, type IIIB

If a classically hypoplastic thumb, type IIIA, presenting with a first car pometacarpal joint, is amenable to reconstruction, a type IIIB case without the basal joint, is classically treated by pollicization. The authors conc ur with this opinion, but found two circumstances in which reconstruction i s an option in a type IIIB thumb, either when an adolescent asks for improv ement of an unstable but utilized thumb, or when a parent definitely refuse s pollicization. In such cases, a free, vascularized metatarsophalangeal jo int is the first step of the reconstruction, followed by classic non-micros urgical steps. The authors reviewed five cases, with a mean follow-up of 7. 8 years. Hypoplasia of the reconstructed thumb, and a limited pinch, allow this option only with restricted indications.