Assessing Rotary Stability of the Knee In Vitro Using Principal Component Analysis

Clinicians typically assess the functional status of the knee subjectively through manipulations to the knee’s passive connective tissue restraint under minimal load. The resulting translation or rotation at a given flexion angle is defined as the laxity of the knee which is used to suggest (in)stability. However, recent studies have shown that instability is not necessarily determined by knee laxity¹. Dynamic stability at the knee is achieved through a complex interaction between soft tissue structures, neuromuscular control and articular geometry. It is during dynamic functional movements, such as walking, that patients suffer from buckling or giving way sometimes resulting in falls ².