The scapholunate ligament.

The effects of scapholunate ligament sectioning on scaphoid and lunate bone three-dimensional kinematics were analyzed using a sonic digitizer method. Carpal bone motions were described using a screw displacement axis concept. After scapholunate ligament sectioning, few significant kinematic changes were observed in the orientation of the screw displacement axes or in carpal bone rotation about the screw displacement axes. The angles between the screw displacement axes of the scaphoid and lunate bones were only minimally affected, indicating that the two bones continued to track well relative to each other. The results indicate that sectioning of the scapholunate ligament does not result in a major disturbance of scaphoid and lunate bone motions.