The anterior cruciate ligament (ACL) remains one of the most injured ligament of the knee. Mispositioning the tunnels remains a common cause of ACL reconstruction failure. A better biomechanical description of this phenomenon is therefore essential. Using the low irradiation biplanar stereoradiographic EOStm imaging system, our group developed a 3D reconstruction method allowing a precise morphologic description of the knee. With this system, the tridimensional positioning of the femoral tunnel can be evaluated in a novel, computerized, precise and reproducible coordinate system. With this referential, our group wish to assist orthopedic surgeons in the restoration of optimal biomechanics in ACL reconstructions.