Comparison of two different types of hybrid Tibial fixations for anterior cruciate ligament reconstruction: a prospective comparative cohort study

Background: Previous studies have compared different kinds of fixations for anterior cruciate ligament reconstruction. Nevertheless, there is no optimal method to date. To the best of authors’ knowledge, there is no article discussing the combination of adjustable suspensory device and interference screw for hybrid tibial fixation. Methods: In total, 66 patients (n = 34, adjustable suspensory device and interference screw; n = 32, cortical screw and interference screw) were analyzed. Their International Knee Documentation Committee score and Tegner activity level scale were evaluated before and after a 2-year follow-up. The Single Assessment Numeric Evaluation score was evaluated after a 2-year follow-up. Physical exams such as range of motion, anterior knee pain (VAS > = 3) and Lachman test were assessed before and at least 12 months after surgery. To evaluate tunnel widening, anteroposterior and lateral view radiography was conducted 1 day and at least 12 months after surgery. A more than 10% change was considered tibial tunnel widening. Mann–Whitney U test, independent t test, paired t test, Fisher’s exact test and chi-squared test were used to compare the variables. Linear and logistic regression models were applied to adjust for potential confounders. Results: No variable except gender (P = 0.006) showed significant difference with regard to demographic data. After adjustment, there was no statistically significant difference between the groups regarding post-operative physical exams. Patients who used adjustable suspensory device and interference screw had lower post-operative Single Assessment Numeric Evaluation score (adjusted β − 8.194; P = 0.017), Tegner activity level scale (adjusted β − 1.295; P = 0.001) and pre-operative degrees of knee flexion (adjusted β − 2.825; P = 0.026). Less percentage of tunnel widening in the lateral view of radiographs was seen in patients in group of adjustable suspensory device and interference screw (adjusted β − 1.733; P = 0.038). No significant difference was observed in the anteroposterior view of radiographs (adjusted β − 0.667; P = 0.26). Conclusion: In these 66 patients, we observed less tibial tunnel widening and lower post-operative functional scores in the group of adjustable suspensory device and interference screw. Both groups displayed similar outcomes of physical exams as well as improvement after operation. The proposed method may become an alternative option. Nonetheless, the quality of our study is still limited, and thus further studies are warranted to determine the efficacy and further application. Trial registration: Joint Institutional Review Board of Taipei Medical University, Taipei, Taiwan (No: N201805094). Study design: Prospective comparative cohort study; Level of evidence, II.