Single- or two-stage revision after failed ACL reconstruction: No differences in re-revision rates and clinical outcomes

Purpose: The surgeons' choice of a single-stage or a two-stage procedure in revision anterior cruciate ligament reconstruction (ACLr) is based on the possibility of reuse of the tibia and femoral bone tunnels after primary ACLr. The purpose of this study was to compare failure rates and clinical outcomes following single-stage and two-stage ACL revisions in a cohort of patients from The Danish Knee Ligament Reconstruction Registry. Methods: Patients identified from 2005 to 2022 with ACL revision and met the following criteria: minimum 2-year follow-up, isolated ACL revision and registered single- or two-stage ACL revision. The primary outcome was ACL re-revision rate. Secondary outcomes were arthrometer sagittal knee laxity (side-to-side difference) and pivot shift (rotational stability difference) evaluated at 1-year follow up. Results: One thousand five hundred seventy-four ACL revisions were included in the study (1331 = single-stage and 243 = two stage). Baseline characteristics showed no difference in relation to age, gender, knee laxity, pivot shift, meniscus injury, cartilage damage or injury mechanism between the two groups. Significant differences were found in relation to the type of graft. No statistical difference in 2-years revision rates between single-stage group 2.79 (95% CI 2.03−3.84) and two-stage group 2.93 (95% CI 1.41−6.05) was found. No significant difference was seen in knee laxity and pivot shift between stage-groups at 1-year follow up. Both groups demonstrated significant improvements in knee stability from baseline to 1-year follow-up. Conclusion: The present study found that ACL revision outcomes were similar in terms of rerevision rates and knee laxity for patients managed with a single- or a two-stage surgical strategy. Level of Evidence: Level III.