Paper 18: Treatment of Lateral Meniscus Tears Influences OA Rate following ACL Reconstruction at 9-year Follow-Up

OBJECTIVES: Recent studies have described an increased risk of osteoarthritis (OA) following ACL reconstruction (ACLR). Systematic reviews have suggested that meniscal pathology, which occurs in up to 60% of patients with ACL injury, increases this risk. The purpose of this study was to determine the influence of lateral meniscus tears and repair versus partial lateral meniscectomy on the risk of OA in patients following ACLR. METHODS: All patients who underwent primary autograft or allograft bone-patellar tendon-bone (BPTB) transtibial ACLR by a single surgeon between 1999-2019, were identified. Revision ACLR, multi-ligamentous reconstructions, and patients with less than 2-year imaging follow-up were excluded. Patients with lateral meniscus pathology at the time of ACLR were identified and treatment (e.g. lateral meniscectomy or lateral meniscus tear) was extracted. OA was defined at follow-up as Kellgren-Lawrence (KL) grade III-IV on plain radiographs. Chi-square tests assessed differences in incidence rates (p<0.05). RESULTS: A consecutive series of 113 patients (57 males, 56 females; age 35.7±11.9 years) with BPTB ACLR were included. The mean follow-up was 9±5 years. The prevalence of lateral meniscus tears was 60.2% (68/113) and the prevalence of lateral compartment OA at follow-up was 14% (16/113) Patients with a lateral meniscus tear were 4.7 times more likely to develop OA compared to patients with no lateral meniscus tear. 20.6% of patients (14/68) with lateral meniscus tear developed lateral OA compared to 4.4% of patients (2/45) without lateral meniscus tear (p=0.0158). Patients who underwent lateral meniscal repair (n=16) had significantly lower prevalence of OA (0/16) compared to patients who underwent lateral meniscectomy (14/52) (p=0.0196). CONCLUSIONS: At nine-year follow-up, patients with a lateral meniscus tear at time of ACLR were more likely to develop OA compared to patients with no lateral meniscus tear and patients treated with partial meniscectomy had higher prevalence of OA compared to those treated with meniscus repair. In patients who require ACLR, care should be taken in evaluating and treating the lateral meniscus to decrease the likelihood of the development of OA. We believe lateral meniscal repair is essential for lateral meniscus tears at the time ACL reconstruction to help avoid development of OA.