Variability of the lateral ligamentous complex of the knee

Abstract

The current study examined the prevalence and morphometric values of three extracapsular ligaments on the lateral aspect of the knee namely lateral collateral ligament, anterolateral and triradiate collateral ligaments in human cadavers. Twenty knees were used. The lateral collateral ligament, anterolateral and triradiate collateral ligaments were present in 70%, 5% and 25% of the cases respectively. The triradiate collateral ligament had three parts namely femoral, tibial and fibular arms with average lengths of 20.03mm, 18.14mm and 16.20mm respectively. The lateral collateral ligament was attached on the lateral condyle of femur and the apex of head of fibula. The anterolateral ligament was attached on the lateral epicondyle of femur anterior to the origin of the lateral collateral ligament and both posterior to the Gerdy’s tubercle and on the lateral meniscus. The triradiate collateral ligament attached on the lateral condyle of femur, descends as the femoral arm and divides at the joint line as the tibial arm (anteriorly) and fibular arm (posteriorly). The tibial arm was attached on the posterior aspect of the Gerdy’s tubercle while the fibular arm was attached on the anterior aspect of head of fibula. The triradiate collateral ligament and the anterolateral ligaments possessed internal attachment to the lateral meniscus and could potentiate meniscal damage. There are considerable ligament variations at the lateral side of knee which should be brought to the knowledge of surgeons and radiologists.

Keywords: Knee, Lateral complex, lateral collateral ligament, anterolateral ligament, triradiate collateral ligament