What is the best femoral fixation of hamstring autografts in anterior cruciate ligament reconstruction? A meta-analysis

Background: Several methods are available for fixing the femoral side of a hamstring autograft in ACL reconstruction and the best method is unclear. Biomechanical studies have shown varying results with regard to fixation failure. Questions/purposes: We asked whether there were any differences with regard to graft failures and functional outcome measures with differing methods of femoral fixation of hamstring autografts in ACL reconstruction. Methods: We systematically reviewed the literature using PubMed, MEDLINE, Scopus, and Cochrane Controlled Trial Register databases with regard to interference screw fixation (aperture fixation) versus noninterference screw fixation (fixation away from the joint line). A meta-analysis was performed of those studies reporting on surgical failures and postoperative International Knee Documentation Committee score. Eight studies met our inclusion criteria of Level I or II evidence. Results: Use of interference screws for femoral fixation resulted in a trend toward decreased risk of surgical failure (relative risk = 0.57; confidence interval, 0.1678-1.0918). When only Level I trials were evaluated, the same trend was noted toward a decreased risk of surgical failures using femoral interference screws (relative risk = 0.52; confidence interval, 0.1794-1.3122). There was no difference in postoperative International Knee Documentation Committee score with Level I and II studies (relative risk = 0.9940; confidence interval, 0.6230-1.5860) or only Level I studies (relative risk = 1.0380; confidence interval, 0.6381-1.6886). Conclusions: The literature suggests a trend toward decreased surgical failures with femoral fixation at the joint line with an interference screw. However, there is no difference when postoperative functional outcomes are compared. Future studies are needed with standardized fixation methods and outcomes assessment to determine the importance of femoral fixation.