The proximal posterior cartilage of the lateral femoral condyle can be used as a reference for positioning the femoral tunnel in ACL reconstruction

Purpose To describe the femoral insertion of the ACL using the posterior proximal cartilage of the lateral femoral condyle as the anatomical reference. Methods Twenty knees were dissected. The X-axis (deep-shallow) and Y-axis (high-low) were determined using the femoral diaphysis and the proximal cartilage of the lateral femoral condyle (point C) as a reference, which were easily identified by direct visualization through the anteromedial portal. The distances to the center of the anteromedial and posterolateral bands and to the center of the ACL were measured. Results The mean distances were 7.2 mm (SD: 0.7) between the center of the anteromedial bundle and the Y-axis (AM-Y), 9 mm (SD: 1.1) between the center of the ACL and the Y-axis (M-Y), and 12.7 mm (SD: 0.9) between the center of the posterolateral bundle and the Y-axis (PL-Y). Regarding the distance (from point C to the distal cartilage along the X-axis), the center of the anteromedial bundle (AM) was 35% (SD: 4.9%), the center of the posterolateral bundle was 62% (SD: 3.7%), and the center of the ACL (M) was 44% (SD: 7%) of the CD distance on average. Conclusion Given the similarity among the specimens in terms of the height of the ACL on the Y-axis in relation to the proximal posterior cartilage of the femoral lateral condyle (point C), this point can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction for single- or double-bundle techniques.