Biomechanical evaluation of tendon graft fixation at the tibial site in anteriorcruciate ligament reconstruction with cortical press-fit bolt

Objective To evaluate the biomechanical strength at the tibial site in anterior cruciate ligament（ACL）reconstruction with cortical press-fit bolt. Methods ACL was reconstructed in 21 fresh frozen cadaver knees using four-stranded hamstring tendon graft.Specimens were divided into cortical press-fit bolt group（n=7）,bioabsorbable interference screw group（n=7）,and intrafix group（n=7）.On each sample,a load-to-failure test was performed.Ultimate failure load,stiffness,displacement of 100N and 400N, and mode of failure were recorded. Results The failure load and stiffness of cortical press-fit bolt fixation were lower than those of intrafix fixation（P＜0.05）.Displacement of 100N and 400N of cortical press-fit bolt fixation was higher than that of intrafix fixation （P＜0.05）.No statistical difference was found in cortical press-fit bolt fixation and bioabsorbable interference screw fixation（P＞0.05）. Conclusion The biomechanical strength of tendon graft fixation at the tibial site with cortical press-fit bolt and bioabsorbable interference screw is similar,and can meet the physiological demand of tendon graft fixation in ACL reconstruction.