A comparative study of medial versus lateral arthroscopic partial meniscectomy on stable knees: 10-year minimum follow-up

Purpose: Our goal was to compare results of partial medial arthroscopic meniscectomy with results of partial lateral arthroscopic meniscectomy and to determine prognostic factors. Type of Study: Retrospective comparative study with statistical analysis. Methods: In this study, 362 medial and 109 lateral isolated arthroscopic meniscectomies are presented with a minimum follow-up time of 10 years. All knees were stable with no previous surgery or traumatic lesion. Results: In this study, 95% of the patients were very satisfied or satisfied with the results of the medial meniscectomy, and 95.5% with results of the lateral meniscectomy (P =.32). According to grades I and 2 of the Intenational Knee Documentation Committee (IKDC) form, 85.8% of the medial meniscectomy group were free of any symptoms, as were 79.7% of the lateral meniscectomy group (P = 11). Radiologic changes after media] and lateral meniscectomy were found in 21.5% and 37.5%, respectively (P = 11). The rates of radiologic changes in patients in whom the contralateral knee was radiologically normal were 22.3% and 39%, respectively (P =.016). The rate of repeat surgeries for osteoarthritis was less than 0.2%. Conclusions: Subjective and clinical results after medial or lateral meniscectomy are quite similar, but radiologic results are significantly worse after lateral meniscectomy. The most accurate way to determine the degeneration caused by the meniscectomy is to evaluate joint space narrowing in patients in whom the contralateral knee was radiologically normal. Otherwise, partial medial or lateral meniscectomy are well tolerated. A better prognosis can be predicted for a patient with an isolated medial meniscal tear with one or more of the following factors: age less than 35 years, a vertical tear, no cartilage damage, and an intact meniscal rim at the end of the meniscectomy. With an isolated lateral meniscal tear, a better prognosis can be predicted if the patient is young and has an intact meniscal rim at the end of the meniscectomy.