Double bundle ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than single bundle ACL reconstruction

Abstract

Purpose: The purpose of this meta-analysis is to compare arthroscopic single bundle (SB) and double bundle (DB) anterior cruciate ligament (ACL) reconstructions in the light of all available randomised controlled trials (RCTs). A meta-analysis of this well-researched topic was performed and subgroup analyses of the medial portal (MP) technique and the transtibial technique (TT) were added as a new idea. The hypothesis was that the DB technique is superior to the SB technique also in subgroup analyses of the MP and TT techniques.

Methods: Instructions of the PRISMA checklist were followed. Systematic literature search from electronic databases, including PubMed, Cochrane library and Scopus was performed to find RCTs that compared the SB and DB techniques. Nine outcomes were used to compare these two techniques. Each study was assessed according to the Cochrane Collaboration's risk of bias tool and three subgroup analyses (minimum 2-years' follow-up, TT technique and MP technique) were performed.

Results: A total of 40 studies were included in this meta-analysis. When analysing all the included studies, the DB technique was superior to the SB technique in KT-1000/2000 evaluation (p < 0.01), IKDC subjective evaluation (p < 0.05), Lysholm scores (p = 0.02), pivot shift (p < 0.01) and IKDC objective evaluation (p = 0.02). Similar results were also found in the subgroup analyses of minimum 2-years' follow-up and the TT technique. However, there were no differences between the two techniques in a subgroup analysis of the MP technique.

Conclusion: Generally, DB ACL reconstruction leads to better restoration of knee laxity and subjective outcomes than SB ACL reconstruction. The subgroup analysis of the MP technique revealed that surgeons can achieve equally as good results with both techniques when femoral tunnels are drilled through the medial portal.

Level of evidence: II.

Keywords: ACL; Anterior cruciate ligament; Double bundle; Meta-analysis; Reconstruction; Single bundle.

Fig. 1

Risk of bias summary. Green low risk of bias, Red high risk of bias, empty unknown risk of bias

Fig. 2

Graphic representation of biases

Fig. 3

Flow diagram of study selection process

Fig. 4

Pooled results of IKDC subjective evaluation. SD standard deviation, CI confidence interval, SB single bundle, DB double bundle

Fig. 5

Pooled results of Lysholm scores. SD standard deviation, CI confidence interval, SB single bundle, DB double bundle

Fig. 6

Pooled results of Tegner scores. SD standard deviation, CI confidence interval, SB single bundle, DB double bundle

Fig. 7

Pooled results of pivot shift. Pos positive, Neg negative, CI confidence interval, SB single bundle, DB double bundle

Fig. 8

Pooled results of KT-1000/2000 arthrometer. SD standard deviation, CI confidence interval, SB single bundle, DB double bundle

Fig. 9

Pooled results of IKDC objective grades. N normal, AN abnormal, CI confidence interval, SB single bundle, DB double bundle

Fig. 10

Pooled results of Lachman test. Pos positive, Neg negative, CI confidence interval, SB single bundle, DB double bundle

Fig. 11

Pooled results of graft failures. CI confidence interval, SB single bundle, DB double bundle

Fig. 12

Pooled results of OA changes. CI confidence interval, SB single bundle, DB double bundle

Fig. 13

Funnel plot assessing publication bias of KT-1000/2000 results, CI confidence interval