Familial flexion-supination deformity at the PIP joint of the finger

The case of a 36-year-old female typist with familial bilateral flexion-supination deformity at the PIP joint of the long fingers is presented. This deformity was ascribed to hypoplasia of the radial lateral band and retaining structures of the long extensor tendon. The deformity was corrected by bridging the second dorsal interosseous muscle and the radial extensor lateral band with a free tendon graft and the reconstruction of retaining ligaments.