Dorsal Dupuytren's disease causing a swan-neck deformity.

A previously undescribed lesion of Dupuytren's disease is presented. An oblique cord coursed parallel to the oblique retinacular ligament of Landsmeer, but inserted proximal to the proximal interphalangeal joint, tethering the central slip and radial lateral band across the intervening transverse retinacular ligament. Contraction of this cord caused a rigid swan-neck deformity. Excision of the cord resulted in complete resolution of the deformity and a full range of motion in the affected digit.