Improperly placed anterior cruciate ligament grafts: correlation between radiological parameters and clinical results

Despite increasing knowledge on knee biomechanics and refined operative techniques, an increasing number of patients are being seen with failed anterior cruciate ligament (ACL) reconstruction. Failure of the reconstruction and further damage to the knee are correlated with improper placement of the graft, which interferes with graft biology and biomechanical demands. Between 1994 and 1995, 63 patients with improperly placed ACL grafts were referred to our institution because of persistent knee instability and pain. A method for analysis of the femoral drill hole on radiography was developed. Before reoperation the radiograph was evaluated by our method, noting the clinical aspects according to the recommendations of the International Knee Documentation Committee (IKDC). The femoral placement of the ACL graft could easily be defined on the lateral and anteroposterior tunnel radiography. The most common error was a femoral placement anterior to the anatomical insertion of the ACL. A significant correlation (P < 0.05) was found between femoral placement of the graft in the sagittal plane and clinical results: the IKDC score declined with increasing distance of the graft from the most isometric bundle of the ACL in the anteroposterior direction.