Arthroscopic Resection of the Discoid Lateral Meniscus: Long-term Follow-up for 16 Years

Purpose: Although the clinical outcome of arthroscopic resection for a torn discoid lateral meniscus is known to be successful in the short term, long-term successful results are necessary. We reviewed the clinical results of arthroscopic meniscectomy for a torn discoid lateral meniscus in 29 knees, with an average follow-up of 16 years. Methods: Subjective symptoms were evaluated with the use of a questionnaire developed by the International Knee Documentation Committee (IKDC). The trends of IKDC scores and patient age at the time of surgery were statistically evaluated through a stepwise piecewise linear regression analysis. Radiographic examination was performed in 15 knees. Results: The average IKDC score was 87 points. Statistical analysis conducted with the use of a regression model of scores revealed that the regression line declined from 90 to 72 points at ages between 25 and 30 years at the time of surgery. Radiographic examination revealed that patients with degenerative changes at the lateral joint compartment, such as joint space narrowing and subchondral sclerosis, were of greater average age at the time of surgery than did patients who did not develop these changes. Conclusions: Results suggest that clinical outcomes associated with this method are successful for longer than 10 years for patients younger than 25 years of age; however, older patients may develop problems caused by degenerative changes that may result from increased stress on the affected joint compartment. Level of Evidence: Level IV, therapeutic case series.