The aim of this study is to introduce the classification of Swanson for congenital anomalies of upper limb modified by the Japanese Society for Surgery of the Hand (the JSSH modification) in English. The Swanson classification has been widely accepted by most hand surgeons. However, several authors have suggested that complex cases, particularly those involving the complex spectrum of cleft hand and symbrachydactyly, are difficult to classify into the classification schemes. In the JSSH modification, brachysyndactyly, so-called atypical cleft hand and transverse deficiency are included under the same concept of transverse deficiency. Cleft hand, central polydactyly, and syndactyly are included in the same category of abnormal induction of digital rays. We believe that the JSSH modification system is effective in providing hand surgeons with the clinical features and conditions for congenital anomalies.
Keywords: Abnormal induction of digital rays; Congenital hand anomaly; Swanson classification; The classification of the International Federation of Societies for Surgery of the Hand; The modification by the Japanese Society for Surgery of the Hand.