Tunnel widening after hamstring anterior cruciate ligament reconstruction is influenced by the type of graft fixation used: A prospective randomized study

Purpose: To compare the incidence of tunnel widening (TW) in patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring graft using either (group A) transfemoral fixation implant (Transfix; Arthrex, Naples, FL) and an interference screw (Arthrex) in the tibial tunnel or (group B) extracortical fixation (EndoButton; Smith & Nephew Endoscopy, Andover, MA) in the femur and bicortical screw and washer distal to the tibial tunnel. Type of Study: Prospective randomized study. Methods: One hundred patients were included and randomized and 87 patients were assessed at a 1-year follow-up. The evaluation included standardized radiographs, KT-1000 data, International Knee Documentation Committee (IKDC) ratings, and Lysholm score. The diameter of the tunnel at the 1 year follow-up was, after correction for magnification, compared with the tunnel diameter of the radiograph from 2 weeks postoperatively. A more than 2-mm enlargement was considered TW. Results: In group A in which transfixation in the femur and interference screw in the tibia was used, 7 of 41 patients had developed femoral TW and 5 of 41 tibial TW. In group B, 20 of 46 patients had TW in the femur and 16 of 46 in the tibia (P <.05, chi-square test). No significant difference was found with respect to Lysholm score, IKDC, or arthrometric evaluation. Conclusions: There was a significant reduction of TW in both the femur and the tibia using fixation points close to the joint, compared with the system where the distance between the fixation points is long. We conclude that the position of the fixation sites and type of fixation device are major factors in the development of TW after ACL surgery. Level of Evidence: Level I, therapeutic study in a prospective randomized clinical trial.