Medial and anterior-posterior ligament stability of the human knee, measured with a stress apparatus.

The five ligaments studied act with a symphonic harmony to provide stability to the knee. The SMCL was of major importance in medial knee stability. The other ligament which provided the most dramatic contribution to knee stability was the PC. It was the only ligament which when sectioned resulted in a significant posterior anterior drawer instability and on three occasions produced a jerk test.