Summary
Meticulous meniscal repair during ACLR resulted in excellent long-term outcomes, with 97.0% survival at a minimum of 8 years, while high BMI and unstable meniscal lesions are risk factors for osteoarthritic progression after ACLR
Abstract
Background
Meniscus tears with anterior cruciate ligament (ACL) injuries contribute to osteoarthritis (OA) progression. Numerous comparative studies have demonstrated a higher risk of osteoarthritis with meniscectomy in patients with ACL reconstruction (ACLR). However, evidence remains limited regarding the long-term outcomes of ACLR with the meniscus preserved by meticulous repair and the factors contributing to osteoarthritis (OA) progression.
Purpose
This study compared the long-term outcomes of ACLR alone without meniscal injury and ACLR with meticulous meniscal repair in cases with meniscal tears. Factors associated with long-term OA progression following ACLR were also evaluated.
Methods
Between 2011 and 2016, 199 patients who underwent primary ACLR by a single surgeon with a minimum follow-up of 8 years were included. Patients were allocated into the ACLR alone (n=60) and ACLR with meniscal procedures (Group 2, n=139). Acute or chronic ACL injury was defined with a criterion of 6 months from ACL injury to index surgery. Survival at minimum 8-year follow-up was assessed as failure was defined as patients who underwent revisional ACLR or subsequent operation due to OA aggravation. Radiologically, the OA progression of medial compartments was evaluated based on K-L grade preoperatively and at the latest follow-up(?=2 refers to the OA progression). Clinically, patient-reported outcomes measurements (PROMs) and anterior and rotatory instability, including Telos anterior stress, Lachmann, and pivot shift tests were assessed pre- and post-operatively. Based on the intraoperative findings, meniscal status was categorized into none, stable, or unstable tears according to the ACL injury severity scale (ACLISS). Meniscal repair status was also classified into no, simple, or complex repair. Factors affecting OA progression were evaluated using a multivariable regression analysis for subgroup analysis.
Results
A mean follow-up was 118.5 months (range, 96 – 163 months). No significant differences were found in patients‘ demographics and acute or chronic ACL injury between the groups. Survival was 97.0% at a minimum 8 years, and no difference was found between the two groups (Group 1, 96.7%; Group 2, 97.1%). None of the patients underwent subsequent operations due to OA aggravation. Radiologically, the incidence of OA progression in medial compartment was 14.5%, and the two groups had no significant difference. Clinically, no significant differences were found in PROMs between the groups. However, postoperative anterior and rotatory instability were significantly higher in Group 2 than in Group 1 (Telos anterior stress test, P=.003; pivot shift test, P=.011). Multivariable regression analysis revealed that patients with BMI=30 (P=.006) and unstable meniscal tears seen intraoperatively (P=.044) were significant factors for OA progression of the medial compartment at long-term follow-up.
Conclusion
Meticulous meniscal repair during ACLR resulted in excellent long-term outcomes, with 97.0% survival at a minimum of 8 years. While OA progression was generally low, it was significantly associated with high BMI and compromised meniscal status.