Congenital adducted thumb: Role of the index transposition flap

This study examines the results of a large length:width ratio transposition flap used for the correction of the congenitally adducted thumb. The flap is elevated from the radial side of the index finger and transposed into the palm parallel to the thenar crease. Long term analysis of flap results included the disappearance of a transverse palmar white line; length:width ratios; angle of abduction of thumb; sensation of flap; and functional assessment of thumb and index finger. There were 49 adducted thumbs operated on and 26 flaps were clinically examined with an average length:width ratio of 3.5:1, with some flaps having ratios of up to 6:1. All adducted thumbs were adequately released with no complications encountered.