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

Abstract

Background: 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.

Questions/purposes: 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?

Methods: 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.

Results: 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).

Conclusion: 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.

Fig. 1

The study flowchart is shown. RCT = randomized controlled trial; Studies included (n = 8; 9 reports) = one study had two reports derived from the same sample.

Fig. 2

The methodologic characteristics of the studies included in our meta-analysis are shown. + = low risk of bias; − = high risk of bias.

Fig. 3A–B

The funnel plots show the standard error (SE) and risk ratio (RR) for the (A) IKDC and (B) pivot shift test scores.

Fig. 4

A comparison of IKDC objective knee evaluation scores is shown. The forest plot shows no significant difference in scores between patients who underwent intraarticular ACL reconstruction only and those who underwent combined intra- and extraarticular ACL reconstruction. M-H = Mantel-Haenszel; intra = intraarticular; extra = extraarticular.

Fig. 5A–B

Comparisons of (A) pivot shift and (B) Lachman test results is shown. The forest plots show a significantly higher proportion of normal or nearly normal scores for patients who underwent combined intra- and extraarticular ACL reconstruction compared with those who underwent intraarticular ACL reconstruction only. M-H = Mantel-Haenszel; intra = intraarticular; extra = extraarticular.

Fig. 6A–B

The overall (A) complication and (B) failure rates after ACL reconstruction are shown. The forest plots show that these rates did not differ significantly between patients who underwent intraarticular ACL reconstruction only and those who underwent combined intra- and extraarticular ACL reconstruction. M-H = Mantel-Haenszel; intra = intraarticular; extra = extraarticular.

Fig. 7A–B

Comparisons of the (A) Lachman test and (B) KT-1000 arthrometer test results after ACL reconstruction with only hamstrings grafts are shown. Theforest plots show a significantly higher proportion of patients with normal or nearly normal Lachman test results and a side-to-side difference less than 3 mm on KT-1000 arthrometer testing in the combined intra- and extraarticular ACL reconstruction group compared with those who underwent intraarticular ACL reconstruction only. M-H = Mantel-Haenszel; intra = intraarticular; extra = extraarticular.