Anatomy of the anterolateral ligament of the knee

Abstract

In 1879, the French surgeon Segond described the existence of a 'pearly, resistant, fibrous band' at the anterolateral aspect of the human knee, attached to the eponymous Segond fracture. To date, the enigma surrounding this anatomical structure is reflected in confusing names such as '(mid-third) lateral capsular ligament', 'capsulo-osseous layer of the iliotibial band' or 'anterolateral ligament', and no clear anatomical description has yet been provided. In this study, the presence and characteristics of Segond's 'pearly band', hereafter termed anterolateral ligament (ALL), was investigated in 41 unpaired, human cadaveric knees. The femoral and tibial attachment of the ALL, its course and its relationship with nearby anatomical structures were studied both qualitatively and quantitatively. In all but one of 41 cadaveric knees (97%), the ALL was found as a well-defined ligamentous structure, clearly distinguishable from the anterolateral joint capsule. The origin of the ALL was situated at the prominence of the lateral femoral epicondyle, slightly anterior to the origin of the lateral collateral ligament, although connecting fibers between the two structures were observed. The ALL showed an oblique course to the anterolateral aspect of the proximal tibia, with firm attachments to the lateral meniscus, thus enveloping the inferior lateral geniculate artery and vein. Its insertion on the anterolateral tibia was grossly located midway between Gerdy's tubercle and the tip of the fibular head, definitely separate from the iliotibial band (ITB). The ALL was found to be a distinct ligamentous structure at the anterolateral aspect of the human knee with consistent origin and insertion site features. By providing a detailed anatomical characterization of the ALL, this study clarifies the long-standing enigma surrounding the existence of a ligamentous structure connecting the femur with the anterolateral tibia. Given its structure and anatomic location, the ALL is hypothesized to control internal tibial rotation and thus to affect the pivot shift phenomenon, although further studies are needed to investigate its biomechanical function.

Does Combined Intra- and Extraarticular ACL Reconstruction Improve Function and Stability? A Meta-analysis

“…The more anatomic double-bundle ACL reconstruction was proposed to overcome potential rotatory instability of the knee, but consensus has not been reached regarding its widespread use [26,27,44]. In addition, studies have shown that the posterolateral bundle contributes little to rotational stability of the knee; this function might be performed by peripheral structures such as the anterolateral ligament [8,28,45].…”

Anterolateral Extra-articular Soft Tissue Reconstruction in Anterolateral Rotatory Instability of the Knee

“…8,9,22 Recently, Kittl et al 10 performed a biomechanical analysis of 8 cadaveric knees and measured the length changes of several combinations of tibiofemoral points (including several previously performed ALES reconstructions) at knee flexion angles between 0 and 90 . Their results suggested that graft placement proximal to the lateral femoral epicondyle tunneled deep to the LCL and connecting to the Gerdy tubercle was the most isometric.…”

“…9,10,13 Although some authors have named the identified structure the "anterolateral ligament," inconsistency on the femoral attachment site is seen. [8][9][10][11] The tibial attachment site is consistently described to be halfway between the tip of the fibular head and the center of the Gerdy tubercle. Discrepancies exist on the association or attachment to the lateral meniscus.…”

“…The anterolateral extra-articular structures of the knee have received much renewed attention. [8][9][10][11] The addition of an anterolateral extra-articular soft-tissue (ALES) reconstruction might be promising in restoring the grossly altered kinematics seen in knees with ALRI.…”

Basic biomechanic principles of knee instability

“…Despite the understanding of the anterolateral structures as a restraint, recent publications of a newly discovered "anterior longitudinal ligament" has engaged the research community in a re-examination of the anatomical, histological, and biomechanical components of the anterolateral capsule [59,60]. Recent anatomic study has reported the dissections of 24 different animal species in which a double lateral collateral ligament (LCL) was observed in three types of primates, but no discrete ALL was ever discovered.…”