Evaluating the tibial and femoral insertion site of the anterior cruciate ligament using an objective coordinate system: a cadaver study.

Purpose: The purpose of this study was to evaluate the tibial and femoral insertion site of the anterior cruciate ligament (ACL) using an objective coordinate system in a cadaver study in order to confirm radiological assumptions of previous investigators who identified the tibial footprint (T) of the ACL on T (5.3; 5.5) and the femoral footprint (F) on F (2.9; 3.5).

Methods: The tibial and femoral insertion site of the ACL was analysed on 30 human cadaver knee joints preserved according to the technique by Thiel. Thirty femora and tibiae were photographed under standardised methods and measured on a coordinate system twice by two examiners with respect to the ACL's footprint. We evaluated these measurements by use of the Cohen's kappa inter- and intraobserver coefficient for two observers.

Results: The photographs and tibial and femoral measurements were achieved with an almost perfect and a substantial agreement of inter- and intraobserver coefficients. Further, we could demonstrate that assumptions of anatomic points in previous radiological investigations were correct.

Conclusions: Our findings confirmed the anatomic tibial and femoral ACL footprint of a previous investigation and further the reproducibility of our coordinate system as an objective method for graft placement evaluation.