What are the Risk Factors for Worse Outcomes of Meniscus Surgery in 23-39-Year-Old Patients Ligamentously Stable Knees?

OBJECTIVES: Meniscus tears are a common and significant source of knee dysfunction in active young adult patients, and no high-quality prospective cohort or RCTs studies exist evaluating patient-reported outcomes in patients in this age group with ligamentously stable knees. Our objective was to identify patient-reported outcomes and patient-specific risk factors from a prospective cohort with a minimum of one-year follow-up following meniscal repair or excision in patients with ligamentously stable knees. We hypothesized that both groups would have significant improvement in outcomes; patients undergoing meniscal repair would have a higher reoperation rate; and articular cartilage injuries, subsequent knee surgery, and certain demographic characteristics would be significant risk factors to inferior outcomes at one year. METHODS: Between February 2015 and December 2017, ligamentously stable meniscal procedures were enrolled and prospectively followed using the outcomes management evaluation system (OME) at Cleveland Clinic. Patients aged 23-39 preoperatively completed a series of validated outcome measurements including the Knee Injury and Osteoarthritis Outcome Score for both Pain (KOOS Pain) and Quality of Life (KOOS QoL). At the time of surgery, physicians documented all intra-articular findings, treatment, and surgical techniques utilized. Patients were followed at minimum of 1-year postoperatively through the OME platform and asked to complete the same outcome instruments done at baseline as well as a question designed to evaluate the Patient Acceptable Symptom State (PASS). The incidence and details of any subsequent knee surgeries were also obtained. Multivariable regression analysis was used to identify significant predictors of outcomes. RESULTS: A total of 371 patients aged 23-39 underwent meniscus excision or repair during the study period. One hundred ninety-four met inclusion criteria, and one-year follow-up was obtained on 72% (n = 139) of the cohort (67% male; median age 32). Both KOOS Pain and KOOS QoL improved significantly at one-year for the entire cohort. Fourteen percent of the cohort (9% on the ipsilateral knee, 5% on the contralateral knee) underwent subsequent surgery at a minimum of one-year postoperatively. The patient-specific risk factors for worse one-year outcomes included preoperative baseline mental capacity score (VR-12 MCS), lower baseline KOOS QoL score, and the intraoperative finding of any grade 3 or 4 chondral changes. CONCLUSION: Young adult patients with ligamentously stable knees undergoing meniscal surgery have significantly improved patient-reported outcomes regardless of excision or repair; however, 14% of patients underwent additional knee surgery at a minimum of one-year postoperatively. The risk factors for worse outcomes include lower baseline mental health score, lower baseline KOOS QoL score, and any grade 3 or 4 chondromalacia scene.