Effect of Graft Fixation Angles in Double-Bundle Anterior Cruciate Ligament Reconstruction, a Systematic Review

ContextRecent reviews have demonstrated a shift towards anatomical double bundle (DB) techniques for anterior cruciate ligament reconstruction (ACLR). However, to our knowledge, there are no reviews that have directly assessed the relationship between bone tunnel graft angle placement in DB ACLR and clinical outcomes. ObjectiveTo investigate the effect of bone tunnel graft angle on clinical outcomes in DB ACLR. Data SourcesWe performed a comprehensive search of the databases PubMed, Scopus, and Embase using the search terms (Fixation OR Angle) AND (ACL OR anterior cruciate ligament) AND (double-bundle OR DB OR double bundle) AND (Reconstruction OR surgery OR arthroscopy) across all time periods. Study SelectionTwo independent authors performed a systematic review of the literature. After removing duplicates and applying inclusion/exclusion criteria on a number of clinical outcomes and other factors, 5 eligible studies were recruited under PRISMA guidelines from the 1032 titles identified. Study DesignSystematic Review Level of Evidence2a Data ExtractionSystematic review of clinical trials and extraction of relevant surgical data. ResultsOur data did not support the original hypothesis and rather showed that increasing the PL bundle angle from 0{degrees} to 90{degrees} leads to better performance on the pivot-shift tests. Having a nonzero AM bundle graft fixation angle, more specifically at or above 20{degrees}, produces better performance on the ATT, Tegner, Lysholm and pivot-shift tests when compared to a 0{degrees} angle. ConclusionsA PL bundle angle at or above 45{degrees} as well as a nonzero AM bundle angle both yielded better clinical outcome scores. However, with respect to a specific combination, there is no consensus on an optimal graft angle combination in DB ACLR currently. Future randomized controlled trials on this topic are recommended to better understand the effects of greater ranges of graft fixation angles on clinical outcome heterogeneity.