Radiographic Incidence of Knee Osteoarthritis After Isolated ACL Reconstruction Versus Combined ACL and ALL Reconstruction: A Prospective Matched Study From the SANTI Study Group

Abstract

Background: Combined anterior cruciate ligament (ACL) reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) have demonstrated reduced risk of graft rerupture as compared with isolated ACLR. However, concerns remain that the risk of osteoarthritis (OA) may be increased by the addition of ALLR. Purpose/Hypothesis: The aim of this study was to evaluate the incidence of OA with isolated ACLR in comparison with ACLR + ALLR at medium-term follow-up. We hypothesized that there would be no differences between the groups. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent ACLR + ALLR with hamstring tendon autograft between January 2011 and March 2012 were propensity matched to patients who underwent isolated ACLR with bone–patellar tendon–bone (BPTB) or hamstring tendon autograft in the same period. Medium-term radiographic evaluation was performed using the International Knee Documentation Committee (IKDC) radiographic OA grading scale, modified Kellgren-Lawrence grade, and the surface fit method to assess percentage of joint space narrowing. Clinical outcomes were assessed with the following measures: IKDC, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and ACL Return to Sport after Injury. Results: A total of 80 patients (42 ACLR + ALLR and 38 isolated ACLR) were analyzed with a mean follow-up of 104 months. There was no significant difference between groups for joint space narrowing in the medial or lateral tibiofemoral or lateral patellofemoral (PF) compartment. However, 36.8% in the isolated ACLR group versus 11.9% in the ACLR + ALLR group had narrowing of the medial PF compartment (P = .0118). A lateral meniscal tear increased the risk of lateral tibiofemoral narrowing by nearly 5 times (odds ratio, 4.9; 95% CI, 1.547-19.367; P = .0123). The risk of medial PF narrowing was >4-fold with an isolated ACLR (odds ratio, 4.8; 95% CI, 1.44-19.05; P = .0179). Between the isolated ACLR group and the ACLR + ALLR group, the secondary meniscectomy rate was 13.2% versus 11.9% (not significantly different). There was no difference between groups in KOOS, Tegner, or IKDC scores. There was also no difference between groups for grades of osteoarthritic change for any classification system. Patients who received a BPTB graft had medial PF joint narrowing in 66.7% of cases as compared with 11.9% in those who received ACLR + ALLR (P = 0.118). Conclusion: ACLR + ALLR did not increase the risk of OA in the lateral tibiofemoral compartment when compared with an isolated ACLR at medium-term follow-up. Isolated ACLR using BPTB was associated with a significantly increased risk of medial PF joint space narrowing. Registration: NCT05123456 (ClinicalTrials.gov identifier).