[Reanimation de l'extension du pouce par transfert de l'extensor indici proprius chez les enfants atteints de pouce flexus adductus congenital].

Congenital clasped thumb is a rare congenital deformity characterized by a permanent contracture of the thumb metacarpo-phalangeal joint. Surgical option often raise in case of failure of the orthopaedic method. We wanted to evaluate the use of the extensor proprius indici (EPI) tendon to reanimate thumb extension in children affected by congenital clasped thumb. We made a retrospective review of children operated in our center between 2005 and 2019. We operated eight children (twelve hands) over this period: nine were grade I, two grade II and one case grade III (arthrogryposis). Medium age at surgery was 18 months (10 to 23 months). In each case, EPI tendon transfer was realized and sutured to the extensor pollici longus. Children were seen in consultation at six weeks postoperative and then mean follow-up was nineteen months. Seven children (87.5%) had a physiologic thumb extension at six weeks. One case of partial loss of extension on the index was noted. One second time of surgery was necessary to change the course of EPI transfer. At six months postoperative, all children could use their thumb with an extension similar to the opposite thumb. Surgery must be proposed in congenital clasped thumb persistent after at least four months of orthopaedic treatment or in cases of severe deformity. Tendon transfer using EPI must be proposed first given the good functionnal results and low morbidity.