The Graft Insertion Length in the Femoral Tunnel during ACL Reconstruction with Suspensory Fixation and Tibialis Anterior Allograft does not Affect Surgical Outcomes, but is Negatively Correlated with Tunnel Widening.

Abstract Purpose To investigate the surgical outcomes of anterior cruciate ligament (ACL) reconstruction using a low-dose irradiated tibialis anterior allograft with a fixed-loop cortical suspension device for the femur based on the graft insertion length (GIL) in the femoral tunnel. Methods Between January 2010 and January 2018, the medical records of consecutive patients who underwent arthroscopic ACL reconstruction using a tibialis anterior allograft fixed with the EndoButton CL for the femur and had at least 2 years of follow-up were retrospectively evaluated. Patients were classified into three groups based on the GIL in the femoral tunnel—Group 1, GIL: 20 mm—and their functional scores, knee stability, and radiographic parameters were evaluated. Results A total of 91 patients were analyzed. There were no statistically significant differences in the functional scores and knee stability between the three groups 2 years postoperatively. However, significant differences were observed in tunnel widening 1 year postoperatively in the femur (P=.045 for absolute value; P=.004 for relative value) and the tibia (P=.014 for absolute value; P=.012 for relative value), revealing that both the femoral and tibial tunnel widened as the GIL decreased. Additional linear regression analyses were employed to identify whether the GIL independently affects tunnel widening. Consequently, the femoral tunnel depth, tunnel diameter, and GIL were found to independently influence femoral tunnel widening (P=.008, P=.019, P Conclusion The GIL in the femoral tunnel during ACL reconstruction using the tibialis anterior allograft with a fixed-loop cortical suspension device for the femur has no significant association with the postoperative functional outcomes and knee stability, but it has a negative correlation with tunnel widening in the femur and tibia.