[Reconstructive surgery of Blauth type III hypoplasia of the thumb]

Thumb hypoplasia type III according to Blauth remains a rare congenital malformation. Recently Manske has promoted reconstruction versus pollicization in the sub-type IIIA where a first carpometacarpal joint is present. However we felt that pollicization is the solution for sub-type IIB where the basal joint is absent. We have reviewed 14 cases of thumb hypoplasia type III, four of them being type IIIB. After performing a first step with a free vascularized second metatarso-phalangeal joint transfer, the secondary steps were identical in both sub-groups. After a mean follow up of five years, no great difference was found in the two sub-groups and basal stability was even better in type IIIB. However the results were functionally and cosmetically inferior to the ones observed after pollicization. When the relatives refuse pollicization or the patient consults late for functional improvement, reconstruction remains worthwhile.