Midterm Outcomes of Isolated Lateral Meniscus Tears in Young Patients (167)
Authors: Duethman Nicholas , Keyt Lucas , Wilbur Ryan , Song Bryant , LaPrade Matthew , Krych Aaron 
Published: October 2021

Objectives: The current literature lacks evidence to guide treatment of isolated lateral meniscus tears in young patients. Accordingly, the purpose of this study was to describe our institutional experience in young patients with lateral meniscus tear with regard to i) treatment trends in meniscectomy and repair ii) long-term patient reported and radiographic outcomes, and iii) failure rates and associated patient and treatment factors. Methods: Patients <26 years of age who underwent surgery for lateral meniscus tears between 2001 and 2017. Patients with ligamentous injury or prior surgeries in the same knee were excluded. Records were reviewed to obtain patient demographics, injury characteristics, surgical details, reoperation rates, repeat imaging, and patient outcome scores. Statistical analysis compared treatment trends over time. Patient reported outcomes (PROs), imaging outcomes, and failure rates were compared by treatment modality. Failure was defined as reoperation, symptomatic osteoarthritis, or IKDC <75. Simple logistic regressions were calculated to predict failure and IKDC based on treatment, type of tear, location of tear, or amount of meniscus removed. Results: 226 knees in 217 patients were identified with average clinical follow-up of 3.2 years. Our cohort consisted of 158 male patients, and average age was 17.4 years (7-25). 138 patients (144 knees) were treated with meniscectomy (partial to complete) (64%) and 79 patients (82 knees) were treated with repair (36%). Repair rates compared to meniscectomy (any degree) increased over time with 63% of lateral meniscus tears from 2013-2017 treated with repair compared to 23% from 2001 -2004 ( P = <.0001). IKDC scores in the meniscectomy group increased from 76.3 ± 9.1 pre-operatively to 97.2 ± 3.9 post-operatively ( P = <.0001) and increased in the repair group from 71.0 ± 11.5 pre-operatively to 97.4 ± 4.1 post-operatively ( P = <.0001).The change in IKDC score was greater in repair (26.0 ± 12.3) than meniscectomy (21.1 ± 9.8) ( P = .002). Reoperation rates in meniscectomy (20%) and repair (20%) were similar ( P = .910). Pre-operative IKDC scores were lower in the repair group ( P = .001), but final IKDC scores were similar ( P = 0.695). Symptomatic OA was noted in 17 patients in the meniscectomy group (22%) and 5 patients in the repair group (11%) ( P = .121). The failure rate was similar between meniscectomy (35%) and repair (28%) ( P = .307). Regression equations evaluating treatment modality, type and location of tear, and amount of meniscus removed did not reach significance in predicting IKDC or failure. Conclusions: In this cohort of young patients with isolated lateral meniscus tears, rate of repair increased over time. IKDC scores improved more in the repair group compared to the meniscectomy patients, however IKDC scores obtained at final follow-up were similar. Rates of symptomatic OA, reoperation, and failure were similar between groups. Treatment modality, type and location of tear, and amount of meniscus removed were not predictive of final IKDC or failure.