Midterm to Long-term Follow-up After Limited Saucerization of a Discoid Lateral Meniscus: Radiological and Functional Outcomes With Age-Dependent Variations

Background: A discoid lateral meniscus (DLM) is the most common meniscus variant and is commonly treated with arthroscopic saucerization. There are mixed data regarding long-term results after surgery, especially in terms of radiological parameters. Purpose/Hypothesis: The aim was to evaluate the functional and radiological results of patients who underwent arthroscopic saucerization for a symptomatic DLM. It was hypothesized that successful outcomes can be achieved by avoiding excessive resection while reshaping only to an extent that prevents mechanical symptoms. Study Design: Case series; Level of evidence, 4. Methods: This study retrospectively analyzed pediatric and adult patients who had a symptomatic discoid meniscus between 2000 and 2018, who underwent arthroscopic saucerization with at least 10 mm of peripheral length, and who had at least 5 years of follow-up. Radiological parameters were measured on both preoperative and follow-up radiographs. Patient-reported outcome measure scores were recorded at follow-up. Results: The study included 57 knees of 53 patients (mean age, 27.6 years [range, 6-65 years]). The mean follow-up duration was 12.1 years (range, 5.0-23.1 years). There were 31 knees in the pediatric group and 26 knees in the adult group. No significant difference was found between the groups or between preoperative and follow-up values for the femorotibial angle ( P > .05). When the preoperative and follow-up Kellgren-Lawrence grades were compared, no change was observed in the pediatric group ( P = .125), while grades were shown to progress in the adult group ( P < .001). The mean Lysholm score was 94.61 ± 7.61 and 84.23 ± 14.90 for the pediatric and adult groups, respectively ( P = .001). Overall, 2 patients underwent arthroscopic surgery because of a symptomatic recurrence of symptoms, and 2 patients underwent arthroplasty because of osteoarthritis. The 10-year survival rate was 90.6%. Conclusion: Limited saucerization of a DLM helped to preserve coronal-plane knee joint alignment. Functional and radiological results were superior in the pediatric patients. Even when alignment was more varus in older patients, preoperative and follow-up femorotibial angles were not statistically significant. This outcome may be used to guide treatment in appropriately selected cases.