Introduction: Individual variations in the anatomy of the knee joint have been suggested to affect the ability to functionally compensate for ACL insufficiency or to put an individual at an increased risk of ACL injury. These variations include the posterior tibial slope, the concavity of the medial tibial plateau, the convexity of the lateral tibial plateau, and the configuration of the femoral condyles.
Method: This anatomical study investigates if there is a correlation between the individual surface geometry of the femorotibial joint and the morphometry of the ACL. These data were assumed to provide evidence whether or not the functional stability of an ACL-insufficient knee may be derived from its radiographic surface geometry. Standardised measurement techniques were used to analyse the surface geometry of 68 human cadaver knees. Data were correlated with the cross-sectional area, the area of insertion and position of the footprint of the ACL and its functional bundles.
Results: Analysis revealed that there was a significant, but weak correlation between the femoral and tibial area of ACL insertion and the depth of the medial and lateral femoral condyle. No correlation was found between the surface geometry of the femorotibial joint and the cross-sectional area of the ACL. The results of this anatomical study suggest that the relationship between the joint surfaces and the morphometry of the ACL primarily is a function of size of the knee joint.
Conclusions: Based on our results, there is no evidence that the stability of the knee can be derived from its radiographic surface geometry.