Impact of type of meniscal tear on radiographic and symptomatic knee osteoarthritis: a sixteen-year followup of meniscectomy with matched controls.

OBJECTIVE: To investigate long-term radiographic and patient-relevant outcome of isolated limited meniscectomy with regard to type of meniscal tear and extent of surgical resection.

METHODS: We studied 155 patients with intact cruciate ligaments (mean +/- SD age 54 +/- 12 years) who had undergone meniscectomy an average of 16 +/- 1 years earlier. The patients were examined using standardized radiography and validated self-administered questionnaires. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to quantify knee-related symptoms, and the definition of a symptomatic knee was determined. We used 68 control subjects matched for age, sex, and body mass index to calculate the relative risks (RRs).

RESULTS: Radiographic tibiofemoral osteoarthritis (OA) (Kellgren/Lawrence grade > or =2) was present in 66 index knees (43%), of which 39 (59%) were considered to be symptomatic according to the KOOS. In total, 77 patients (50%) had a symptomatic index knee. In a multivariate model, degenerative meniscal tears were associated with both radiographic OA (P = 0.030) and combined radiographic and symptomatic OA (P < or = 0.015). The RRs for combined radiographic and symptomatic OA after degenerative and traumatic types of meniscal tear were 7.0 (95% confidence interval [95% CI] 2.1-23.5) and 2.7 (95% CI 0.9-7.7), respectively, compared with matched controls.

CONCLUSION: An isolated meniscal tear treated by limited meniscectomy is associated with a high risk of radiographic and symptomatic tibiofemoral OA at 16-year followup. Factors associated with worse outcome were degenerative meniscal lesions and extensive resections. We suggest that degenerative meniscal tears may be associated with incipient OA, and that the meniscal tear signals the first symptom of the disease.