De Smet L, Fabry G
University Hospital, Department of Orthopedics, Katholieke Universiteit Leuven, Pellenberg, Belgium.
Acta Orthop Belg. 1993;59(3):269-72.
The orientation of the sigmoid notch of the distal radius is related to the ulnar length. In the ulna plus there is a spherical notch, in the ulna minus it is conical and in neutral it is usually cylindrical, sometimes conical.