Anatomical variation in the anterolateral ligament of the knee and a new dissection technique for embalmed cadaveric specimens

Abstract

Claes et al. recently documented and described the anterolateral ligament (ALL) of the knee, demonstrating its existence in 97% of their samples. Here, we further examined the anatomy of this ligament, documented its morphological variation, and assessed the feasibility of its dissection in preserved cadaveric specimens. To achieve this, we dissected 53 preserved cadaveric knees and documented their morphological variation in the anterolateral ligament. The originally described dissection technique for identifying and following the ALL requires flexion of the knee, a state which is often not possible in stiff, preserved cadavers. Here, we describe and confirm the feasibility of an alternate dissection technique in which the quadriceps femoris tendon is incised, for use on specimens in which flexion of the undissected knee is not possible. We also identify a novel technique for assessing whether the anterolateral ligament is absent from a specimen or has simply been obliterated or overlooked, using the lateral inferior genicular vasculature. These dissection techniques have great potential for the dissection of preserved cadavers used in gross anatomy laboratories, and we discuss the applications of such an approach in student-led dissections. Our dissections also uncovered noticeable variation in the anterolateral ligament course and position. Most notably, it often inserts significantly more laterally than the classical presentation (30.2%), or originates more proximally with superficial fibers extending superiorly and laterally over the distal femur (7.5%).