[Congenital thumb hypoplasia. Clinical study of twenty patients].

Congenital hypoplasia of the thumb is often seen in association with longitudinal failure of formation of the radius. A clinical study of 20 children, with 26 cases of hypoplasia of the thumb was conducted to evaluate the surgical indications according to the stage of the malformation. The results were evaluated for each patient of the study, with the position of the thumb, its spontaneous movements and its function. In grade II hypoplasia, treatment consisted of reanimation of the hypoplastic thumb by one or more tendinon transfers. In grade IV and V, pollicisation is the treatment of choice. In our experience, the surgical indications raise a problem essentially in grade III hypoplasia of Blauth's classification. In these cases, pollicisation gives the best results. Reanimation of the thumb with tendinon transfers can sometimes be used when parents refuse amputation of the thumb, when the first metacarpal is not excessively hypoplastic, and when the child is old enough to allow early physiotherapy.