Anterolateral ligament of the knee, fact or fiction?

however, an anterolateral ligament (ALL) was never seen in any of the examined species. This suggests a negative selection against this feature in our own evolution. We have also dissected several fetuses aged 18–22 weeks, and again no distinguishable anterolateral ligament was identified within the capsule. When evaluating the macroscopic anatomy, histology and radiology of the anterolateral capsule in adult human cadaveric specimens, only 30 % of the specimens showed a discrete capsular thickening of 2–4 mm on magnetic resonance imaging (MRI), much thinner than, for example, the LCL. During arthroscopic trans-illumination of these same specimens, no thickening of the anterolateral capsule was seen. Interestingly, on further analysis, internal rotation and flexion of the knee caused a fold in the anterolateral capsule, mimicking a thickening. Histology of this capsular thickening was performed and compared with that of the LCL. The LCL showed a clear linear alignment of collagen fibres, while the anterolateral capsule showed some alignment but not pronounced enough to constitute a true ligament [3]. In our experience of evaluating the anatomy of the anterolateral capsule in more than 150 patients with an A heated debate is ongoing regarding the anatomy of the anterolateral capsule of the knee. Current literature provides a multitude of descriptions. Researchers have argued that the capsule contains a true ligament, while others suggest it merely displays a thickening; yet others fail to show any distinguishable capsular structures. Given the recent surge in the literature on the anterolateral capsule of the knee, it is of great importance to be meticulous in evaluating every aspect of it, including the anatomy, histology, biomechanics, kinematics and clinical implication prior to recommending on its repair or reconstruction. While performing anatomic dissections on 24 different animal species, we have consistently found a double lateral collateral ligament (LCL) in three types of primates;