Morphometric Analysis of Anatomy of Anterior Cruciate Ligament of Knee and its Attachments - a Cadaveric Study in Indian Population

INTRODUCTION: The Anterior Cruciate Ligament tends to stabilise the knee in various range of extension and flexion. Precise study of anatomy, attachments and position of bundles is important for successful ACL reconstruction. In our study, we attempt to assess general anatomy of ACL, determine and compare its morphometric data pertaining to length and width and its tibio-femoral foot prints in different gender and secondarily determine changes in the same during ACL dynamics witnessed during knee flexion changes. MATERIALS AND METHODS: A total of 19 knees from 10 cadavers were used in the research with mean age of 61±7 years. After dissecting the skin, muscles, patellar and articular capsule were removed and bundle attachments were studied. Thereafter the relative length, width and stiffness of ACL bundles at 0, 90, 140 (maximum) angles of knee flexion were measured along with maximum horizontal and vertical bundle footprints at tibio-femoral attachments were recorded. RESULTS: Mean length and width of insertion of anteromedial (AM) bundle on the tibial surface was 8.8mm and 9.0mm in males and 8.1mm and 8.8mm in females. Furthermore, that of PL bundle was 9.1mm and 7.8mm in males and 8.9mm and 7.1mm in females. CONCLUSION: The anteromedial (AM) bundle and posterolateral (PL) bundle of ACL were found to be most relaxed at full extension and were most taut at maximum flexion of 140°. AM bundle underwent greater stretching and change of length in comparison to the PL bundle, indicating that it is comparatively a more dominant bundle.