Graft Inclination Angle is Associated with the Outcome of the Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament reconstruction (ACLR) surgery is frequently used to manage anterior cruciate ligament (ACL) tear. The non-anatomic positioning of the graft may cause graft failure. This study aimed at evaluating the association of the ACLR outcome with factors affecting the anatomic positioning of the graft, including the tibial tunnel, femoral tunnel, and graft inclination angles. Methods: A total of 37 patients, who had undergone ACLR surgery, were included in this retrospective study. All surgeries were performed by the transportal arthroscopic reconstruction technique. The tibial and femoral tunnel angles were evaluated on both anteroposterior (AP) and lateral radiographs. Graft inclination angle was evaluated on AP radiograph. Outcome measures included: International Knee Documentation Committee (IKDC), the Lachman and the pivot shift test, and KT-1000 arthrometer score. Results: The mean age of the patients was 30.1 ± 9.4 years. The ACLR surgery was successful in 36 (97.3%) patients and failed in one patient (2.7%). No significant association was found between the femoral/tibial tunnel angles and outcome measures on both AP and lateral view. A negative significant correlation was found between the IKDC score and the graft inclination angle (P = 0.049, r = -0.326), indicating that with graft angle between 20° and 36°, the more horizontal graft was associated with better IKDC score. Conclusions: According to the results, graft inclination angle, yet not femoral/tibial tunnel angles, were associated with the outcome of the ACLR surgery However, further studies are required to address the inconsistent results of different investigations.