The lateral pivot shift: a symptom and sign of anterior cruciate ligament insufficiency.

The lateral pivot shift(LPS) is a special form of lateral compartment instability arising from anterior cruciate insufficiency. It is characterized by anterior subluxation of the tibial plateau out from beneath the lateral femoral condyle. As a consequence of this form of instability, deleterious changes of the knee joint take place, including meniscal tears, and articular cartilage erosions. The eventual result of continued symptomatic instability is late osteoarthritis of the knee. LPS is the most prominent form of instability of the knee in patients complaining of "giving way" of the knee, and recovery from severe soft-tissue injury to the knee joint.