Resident’s Ridge Formation Can Be Explained by ACL Force-Induced Bone Remodeling Available to Purchase

The reconstruction technique of the human anterior cruciate ligament (ACL) has been improved in the last decade. Current ACL reconstruction surgery aims to make femoral bone tunnels for graft fixation as close to the anatomical position of the ACL insertion site; the posterior-superior border of the lateral wall of the intercondylar notch of the femur^1,2). Such a surgical technique is called “anatomical ACL reconstruction”. Biomechanical studies indicated that joint stability is highly restored in the anatomical ACL reconstruction as compared with the conventional ACL reconstruction³⁾. In addition, the cortical bone beneath the ACL attachment site is thicker⁴⁾, therefore it is beneficial to use the area for graft fixation. In order to succeed the anatomical ACL reconstruction, it is the most crucial to microscopically identify the anatomical site of the ACL insertion site. Previous studies indicated that the Resident’s ridge is located just anterior to the ACL femoral attachment^4–6), therefore, can be used as a reference landmark for the anatomical ACL reconstruction. Although the Resident’s ridge seems to win endorsements of the role in the ACL reconstruction, no explanation was proposed so far as regard with the reason for ridge formation. The author believes that the formation of the Resident’s ridge can be biomechanically explained. Therefore, the objective of the present study was to propose a biomechanical hypothesis as regard with the Resident’s ridge formation, and to validate the hypothesis through a finite element method (FEM) analysis of ACL force-induced bone remodeling.