Graft Signal and Clinical Outcomes of Single-bundle Anterior Cruciate Ligament Reconstruction and Double-bundle ACLR: The Different Effects Related with Posterior Tibial Slope

Abstract

Background: The effects of single-bundle and double-bundle ACL reconstruction are still controversial and patients with different anatomy may need to choose different surgery. The aim of the study was to assess the relationship between graft maturation and clinical outcomes, identify the risk factors, and compare the results after single/double-bundle ACL reconstruction. Methods: A single-surgeon series of 147 patients with a median follow-up of 149.7 months (range, 144-189 months) underwent isolated primary ACL reconstruction (SB-ACLR group: n = 74; DB-ACLR group: n = 73). Clinical outcomes included the pivot shift test, IKDC, Lysholm, and Tegner scores. Signal intensity (SI) of the graft, and bone anatomy were also assessed. Results: Significant correlations between graft SI and last clinical outcomes were shown. Lateral tibial slope (LTS) (β = 0.09) and medial tibial slope (MTS) (β = 0.09), or their sum (STS) greater than 12° (β = 1.16) were determined as the risk factors of graft SI among SB-ACLR group patients. No independent risk factor for graft SI of patients in the DB-ACLR group was observed. Compared to the other three groups, the STS > 12° group in SB-ACLR showed significant differences in the clinical outcomes. Conclusions: Late graft SI is negatively correlated with the clinical outcomes. It might be affected by specific anatomic features in patients with SB-ACLR, including medial tibial slope, lateral tibial slope, and their sum, and mediated the effect on clinical outcomes. Patients with STS > 12° may consider choosing DB-ACLR to expect better long-term knee function after surgery. Trial registration: No. IRB00006761-2011097 and NCT03984474. Level of Evidence: Retrospective Study, Level III.