Case report of a bifurcated fibular (lateral) collateral ligament: which band is the dominant one?

Background: The fibular collateral ligament is a permanent and extracapsular ligament of the knee joint. It is located on the lateral aspect of the knee and extends from the lateral epicondyle of the femur to the lateral surface of the head of the fibula. As one of the main knee joint ligaments it is a stabilizer of the posterolateral corner of the knee and resists varus stress. The case report displays the bifurcated variant of the fibular collateral ligament. The aim of this study is to determine which of those bands should be considered dominant. Materials and methods: Classical anatomical dissection was performed on the left knee joint. The fibular collateral ligament was thoroughly cleansed around its origin, distal attachments, and course. Appropriate morphometric measurements were collected. Results: A bifurcated variant of the fibular collateral ligament with inverted proportions of its two bands ( main and accessory one) constitutes our findings. It originated on the lateral epicondyle of the femur. Then it divided into two bands (A1 and A2). Band A1 inserted to the head of the fibula. A bony attachment of band A2 was located on the lateral aspect of the lateral condyle of the tibia. Conclusions: Although the fibular collateral ligament is a permanent structure it presents morphological variations. It is important to constantly extend morphological knowledge for all scientists concerned in anatomy.