Bony and soft tissue landmarks of the ACL tibial insertion site: an anatomical study

Abstract

To identify and describe reliable landmarks for tibial tunnel placement in anatomical ACL reconstruction. Eight non-paired cadaveric knees were used. After dissection, the tibial plateaus, menisci and ACL insertions were grossly observed to identify anatomical landmarks and relate them to the ACL insertion site. The specimens were scanned with a laser scanner, and 3-Dimensional images were obtained. Measurements of the ACL tibial insertion were taken. The center of the ACL and its bundles was measured regarding the distance from the medial tibial eminence and intermeniscal ligament. The medial tibial eminence demonstrated a constant relationship with the ACL tibial insertion site center and its bundles, as well as the intermeniscal ligament. The anterior root of the lateral meniscus had a variable relationship with the ACL tibial insertion. The length of the ACL tibial insertion was 18.1±2.8mm and the width was 10.7±1.9mm. The width of the AM bundle was 11.1±2.1mm and the PL 7.9±2.0mm. The ACL center was 9.1±1.5mm posterior to the intermeniscal ligament and 5.7±1.1mm anterior to a projected line from the apex of the medial tibial eminence. The center of the AM bundle was at 4.6±0.7mm posterior to the intermeniscal ligament. The center of the PL bundle was 1.4±0.7mm anterior to the medial tibial eminence. The medial tibial eminence and the intermeniscal ligament may be used as landmarks to guide the correct tunnel placement in an anatomical ACL reconstruction.