Arthroscopic treatment of the symptomatic discoid lateral meniscus improves the knee function in the long-term: a ten-year follow-up study.

Purpose: Discoid lateral meniscus (DLM) is a common meniscal anatomic disorder and can cause irreversible knee consequences. The long-term clinical outcomes of DLM management remain unclear. Moreover, several potential factors would influence the long-term functional outcomes. The factors also remain unclear. This study aims to evaluate the long-term clinical outcomes of the arthroscopic management of the DLM and to identify the patients' factors affecting the long-term results.

Methods: Medical records were retrospectively examined for patients with symptomatic unilateral DLM who underwent arthroscopic procedures between January 2004 and August 2011. The characteristics of DLM, the preoperative and the long-term postoperative visual analog scale (VAS), the International Knee Documentation Committee (IKDC) score, Lysholm, and Yulish scores were evaluated. Data were collected, processed, and analyzed using SAS software version 9.2. Univariate and multivariate analyses were performed to identify the factors influencing the long-term outcomes of the DLM arthroscopy.

Results: A total of 128 patients were included, most of whom were females (68.7%). The median age of the included participants was 24 (16-31) years old. The median duration of symptoms was 23.3 (10, 31) months, and the median follow-up duration was 126.2 (113, 140) months. The functional scores significantly improved postoperatively compared to the preoperative scores; VAS (1.65 ± 1.17 vs. 6.08 ± 1.31), Lysholm (91.39 ± 5.05 vs. 77.51 ± 10.19), and IKDC (84.63 ± 7.69 vs. 67.89 ± 9.56), respectively; p<0.05. Multivariate analysis revealed that gender, the status of self-reported instability, preoperative VAS, Yulish MR cartilage grade, and Lysholm score had a significant correlation with the worsening of the final follow-up IKDC scores.

Conclusions: Arthroscopic procedure significantly improved the long-term joint function of the DLM patients, as evidenced by the sustained improvement of the VAS, Lysholm, and IKDC scores. These clinical outcomes were greatly influenced by gender, the status of self-reported instability, preoperative Yulish MR cartilage grade, VAS, and Lysholm score.