Position of the Lateral Intercondylar Ridge and Anterior Cruciate Ligament Bony Insertion Area in Relation to the Wall and Roof of the Femoral Notch

Abstract

Purpose This study assesses the positioning of the lateral intercondylar ridge (LIR) and the anterior cruciate ligament (ACL) femoral insertion area (FIA) in relation to the femoral notch roof and lateral notch wall and examines their correlation with posterior notch outlet width. Method 45 dried femurs underwent 3D scanning and analysis. A cutting plane was established to divide the intercondylar roof from the condylar wall based on three points. LIR length and position on the roof and wall were measured, alongside distances to key landmarks. Total ACL-FIA was measured, as well as the area on the roof and wall of the intercondylar notch. Results A significant correlation was found between LIR positioning on the roof and notch width. LIR averaged 16.18 mm, with 30.86% on the roof, while ACL-FIA averaged 134.19 mm², with 31.55% on the roof. Posterior notch outlet width averaged 24.34 mm. The distance between the most proximal part of the LIR to the posterior intercondylar line averaged 4.87 mm and 12.46 mm to the most proximal, high deep point of the cartilage border of the lateral femoral condyle. Conclusion These findings offer valuable insights for femoral tunnel positioning during ACL reconstruction by quantifying LIR length and ACL-FIA surface on the intercondylar notch roof for the first time, revealing their extension onto the roof and their potential implications.