Comparison of clinical outcomes between isolated ACL reconstruction and combined ACL with anterolateral ligament reconstruction: a systematic review and meta-analysis

Background To compare the clinical outcomes between isolated cruciate ligament reconstruction (ACLR) and combined ACL with anterolateral ligament reconstruction in chronic ACL injury especially with rotary instability problem. Methods Systematic searches were conducted of literature published up to July 2021 on PubMed, Google Search, and Cochrane databases for studies comparing isolated ACLR and ACL with anterolateral reconstruction. Two reviewers independently determined eligibility, extracted outcome data, and assessed the risk of bias of eligible studies. Pooled clinical outcomes used random effects with mean differences and risk ratio for continuous and dichotomous variables, respectively. Results After excluding 49 articles based on full-text screening, six studies were identified which met the inclusion criteria in the meta-analysis. Clinical outcomes such as residual laxity, rotatory instability, and graft failure were compared between isolated ACLR and combined ACL and anterolateral stability reconstruction. Overall, both clinical outcomes of isolated ACL and combined ACL with anterolateral reconstruction show improvement results in pivot shift test, the absence of residual laxity and incidence of graft failure. Compared to isolated ACLR, the prominent postoperative result was by combined ACL with anterolateral reconstruction which had significant differences in laxity outcome based on (I-2 = 89%, p < 0.00001) and (MD = 0.71, 95%CI: 0.33-1.08, p = 0.00002). Conclusions The combined ACL with anterolateral reconstruction tended to have superior clinical outcomes, especially in the absence of residual laxity, compared to the isolated ACLR, but the other results were not significantly different statistically. Combined ACL and anterolateral reconstruction were not performed routinely for patients undergoing ACL reconstruction, but more suitable for chronic rotatory instability problem.