Purpose of the study: The purpose of this retrospective multicentric analysis was to study the functional and radiological outcomes at more than 20 years of 89 arthroscopic lateral menisectomy procedures performed on stable knees.

Materialandmethod:The series included 89 arthroscopic lateral meniscectomies performed on knee with intact anterior cruciate ligaments (ACL). Mean follow-up was 22±3 years; 56 male, mean BMI 25±4, mean age at meniscectomy 35 years, mean age at last follow-up 57 years. Most of the injuries were vertical (41%), complex (22%) and radial (20%) lesions. The middle segment was involved in 79%. The meniscectomy removed more than one-third of the meniscus in 67%. All patients were reviewed by an independent operator for subjective assessment KOOS (100% normal) and IKDC, and for objective clinical and radiological measurements (IKDC). P< 0.05 was considered statistically significant. There was no independent control group.

Results: Revisions were performed for 16% of the knees. Intense or moderate activity was maintained by all patients. The subjective IKDC score was 71.1±23, comparable with an age and gender matched population. The mean KOOS score was 82% for pain, 80% for symptoms, 85% for daily activities, 64% for sports, and 69% for quality of life. The rate of of osteoarthritis was 56%, and 44% of patients had a difference between the two knees for osteoarthritis. The incidence of osteoarthritis was 53% and shift to valgus on the arthritic side was significantly associated with osteoarthritis, while the opposite side was well aligned. The knee was pain free in 27% of patients. Significant factors for good prognosis were age less than 38 years at first operation, moderate BMI, and minimal cartilage damage (grade 0 or 1).

Conclusion: After the first postoperative year after arthroscopic lateral meniscectomy on a stable knee, the results remain stable and satisfactory for more than 22 years. Nevertheless, patients aged over 40 with a high BMI and cartilage damage at the time of the first operation have a less encouraging prognosis.