Femoral Origin of the Anterolateral Ligament: An Anatomic Analysis

Purpose: To determine the location and variability of the anterolateral ligament (ALL) femoral origin. Methods: The ALL was dissected and examined in 52 embalmed specimens, and the femoral origin was isolated. The presence of a bony or soft-tissue attachment, the relation to the lateral collateral ligament, the average diameter of the proximal origin, and the specific location of the origin relative to the lateral femoral epicondyle were recorded. Results: The ALL was present in all 52 specimens, with a mean diameter of 11.85 mm, and was consistently attached to bone in all specimens. The ALL consistently overlapped the lateral collateral ligament near its attachment, with the location of the origin directly on the lateral epicondyle in 12 specimens (23%), with a shared lateral femoral condyle and with the origin slightly posterior and proximal to the lateral epicondyle in 30 specimens (58%), and with the origin completely posterior and proximal to the lateral epicondyle in 10 specimens (19%). Conclusions: The ALL showed a consistent bony origin overlapping the lateral collateral ligament in all specimens, with some variability in the femoral attachment, ranging from directly on the lateral epicondyle to posterior to the lateral epicondyle. Clinical Relevance: The identification and description of the femoral origin of the ALL are crucial in understanding its role in the stability of the knee, as well as determining the appropriate position for the femoral origin placement in ALL reconstruction.