Congenital anomalies of the upper limb among the Japanese in Sapporo.

Nine hundred and forty three patients with nine hundred and fifty-five congenital upper limb anomalies are classified according to the Swanson's classification. Relative incidence of each type of anomaly, sex incidence, affected side, associated abnormalities and familial history are analysed. The occurrence of congenital upper limb anomalies is also compared with Chinese and Western studies. The characteristic feature in this series is that the incidence of typical syndactyly is not as high as expected. Two problems of Swanson's classification encountered in this analysis are discussed. One of the problems is the relation between polydactyly, syndactyly and typical cleft hand. The other is the relation between brachysyndactyly, atypical cleft hand and transverse deficiency.