Abstract
OBJECTIVES: Lateral meniscus posterior root tear (LMPRT) is often accompanied by anterior cruciate ligament (ACL) injury and increases both anterolateral rotatory instability and load on the articular cartilage. However, studies on the outcomes of LMPRT repair are scarce. Thus, we aimed to evaluate the clinical outcomes of LMPRT with ACL reconstruction (ACLR). METHODS: This study included 107 patients who underwent primary ACLR using autologous hamstring tendons and were followed up for two years. Twenty-five patients who underwent simultaneous LMPRT repair were classified into the LMPRT group, and 82 patients who underwent isolated ACLR without any meniscal procedures were classified into the isolated ACLR group. Both subjective and objective outcomes were measured before and two years after surgery, and subjective outcomes were also collected at three months and one year post-surgery. The clinical outcomes of the two groups were compared after adjusting for age, sex, body mass index (BMI), pre-injury Tegner scale scores, and time from injury to surgery. Improvement in clinical outcomes was evaluated using repeated analysis of variance (ANOVA). RESULTS: After adjusting for all covariates, the preoperative pivot shift grade was higher in the LMPRT group than in the ACLR group. Preoperative subjective outcomes were significantly poorer in the LMPRT group than those in the isolated ACLR group, except for the International Knee Documentation Committee score. At the two-year follow-up, the Lysholm score in the LMPRT group was higher than that in the ACLR group. The LMPRT group exhibited a significantly greater improvement in subjective outcomes than that in the isolated ACLR group. Improvements in the objective measurements of the two groups were not significantly different. Although sagittal extrusion increased, the lateral meniscus extrusion (LME) width significantly decreased by an average of 0.4 mm in the LMPRT group before and one year after surgery. CONCLUSION: Patients with LMPRT and ACL injuries simultaneously had higher pivot-shift grades and reported worse subjective outcomes prior to surgery compared to those with isolated ACL injuries; however, the clinical outcome of ACLR with LMPRT was not inferior to that of isolated ACLR at two years postoperatively. Following LMPRT repair, the patients were able to restore knee joint stability and showed similar recovery levels as patients with isolated ACLR for at least a short period.