Morphology of the femoral insertion of the lateral collateral ligament and popliteus tendon

Abstract
To clarify the femoral insertion of the lateral collateral ligament (LCL) and popliteus tendon (PT) and related osseous landmarks on three-dimensional images. Twenty-six non-paired, formalin-fixed human cadaveric knees were evaluated in this study. Femoral insertion of the LCL and PT was identified and marked. Three-dimensional images were created, and the surface area, location, positional relationships, and morphology of the femoral insertion of the LCL, PT, and related osseous structures were analysed. The mean surface areas of the LCL and PT femoral insertions were 55.8 ± 25.0 and 52.5 ± 24.2 mm2, respectively. Variations in the positional relationships between the LCL and PT insertions (PT inserted parallel and posterior to the LCL insertion to the long axis of the femur) were observed. The lateral epicondyle and popliteal sulcus could be clearly identified as osseous landmarks on three-dimensional images in all knees. Most of the LCL was inserted postero-distal to the apex of the lateral epicondyle, and the PT was inserted at the anterior end of the popliteal sulcus in all knees. We observed variation in the positional relationship between the femoral insertion of the LCL and PT. However, the relationships between their insertions and osseous landmarks were consistent. The findings of this study contribute to the understanding of the PLC osseous anatomy and should assist surgeons in performing PLC surgery with a more anatomic perspective.