Does Combined Intra- and Extraarticular ACL Reconstruction Improve Function and Stability? A Meta-analysis

ACL reconstruction aims to restore knee function and stability; however, rotational stability may not be completely restored by use of standard intraarticular reconstruction alone. Although individual studies have not shown the superiority of combined ACL reconstruction compared with isolated intraarticular reconstruction in terms of function and stability, biomechanical principles suggest a combined approach may be helpful, therefore pooling (meta-analyzing) the available randomized clinical studies may be enlightening. We performed a meta-analysis to determine whether combining extraarticular with intraarticular ACL reconstruction would lead to: (1) similar knee function measured by the IKDC evaluation, return-to-activity, and Tegner Lysholm scores, compared with isolated intraarticular reconstruction; (2) increased stability measured by pivot shift and instrumented Lachman examination; and (3) any differences in complications and adverse events? To identify randomized controlled trials (RCTs) comparing combined intra- and extrarticular ACL reconstruction (combined reconstruction) with intraarticular ACL reconstruction only, we searched MEDLINE, EMBASE, SPORTDiscus, Latin American and Caribbean Health Sciences (LILACS), and the Cochrane Central Register of Controlled Trials, and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The main outcomes we sought were patient function and stability and complications after ACL reconstruction. Of 386 identified studies, eight RCTs were included (n = 682 participants; followup, 12-84 months; men to women ratio, 2.17:1) in our meta-analysis. Study quality (internal validity) was assessed using the Cochrane risk-of-bias tool; in general, we found a moderate quality of evidence of the included studies. When functional outcomes were compared, we found no difference between patients who underwent intraarticular ACL reconstruction only and those who underwent combined reconstruction (IKDC, return-to-activity, and Tegner Lysholm scores). However, patients who underwent combined reconstruction were more likely to show improved stability based on the pivot shift test (risk ratio [RR], 0.95; 95% CI, 0.91-0.99; p = 0.02) and Lachman test (RR, 0.93; 95% CI, 0.88-0.98; p = 0.01). In addition, our meta-analysis found no difference between the two treatments in terms of general complications or adverse events (RR, 1.31; 95% CI, 0.70-2.34; p = 0.40) and the proportion of patients whose reconstructions failed (RR, 2.88; 95% CI, 0.73-11.47; p = 0.13). Combined intra- and extraarticular ACL reconstruction provided marginally improved knee stability and comparable failure rates but no difference in patient-reported functional outcomes scores. Complications and adverse events such as knee stiffness may be underreported and technical factors such as graft placement were difficult to evaluate. Future studies are needed to determine whether the small differences in additional stability warrant the potential morbidity of the additional extraarticular procedure and to determine long-term failure rates.