Long-term rates of knee arthroplasty in a cohort of 834 393 patients with a history of arthroscopic partial meniscectomy

AIM To determine the long-term risk of undergoing knee arthroplasty in a cohort of patients with meniscal tears who had undergone arthroscopic partial meniscectomy (APM). METHODS A retrospective national cohort of patients with a history of isolated APM were identified over a twenty-year period. Patients with prior surgery to the same knee were excluded. The primary outcome was knee arthroplasty. Hazard ratios were adjusted by patient age, sex, year of APM, Charlson comorbidity index, regional deprivation, rurality, ethnicity. Risk of arthroplasty in the index knee was compared to the patient’s contralateral knee (with versus without a history of APM). RESULTS 834,393 patients were included (mean age 50 years; 37% female). Of those with at least 15-years of follow up, 13.49% (16256/120493; 95% CI 13.30-13.69) underwent subsequent arthroplasty within this time. In women, 22.07% (95% confidence interval [CI] 21.64-22.51) underwent arthroplasty within 15 years in comparison to 9.91% men (95% CI 9.71-10.12), corresponding to a risk ratio (RR) of 2.00 (95% CI 1.95-2.06). Relative to the general population, patients with a history of APM were 10.27 times (RR; 95% CI 10.07-10.47) more likely to undergo arthroplasty rising to 39.62 times (RR; 95% CI 27.68-56.70) at a younger age (30-39-years). In patients with a history of APM in only one knee, the risk of arthroplasty in that knee was greatly elevated in comparison to the contralateral knee (no APM) (HR 2.99; 95% CI 2.95-3.02). CONCLUSIONS Patients developing a meniscal tear, undergoing APM, are at greater risk of knee arthroplasty than the general population and this risk is three-times greater in the patient’s affected knee than the contralateral knee. Women in the cohort were at double the risk of progressing to knee arthroplasty versus men. These important new reference data will inform shared-decision making and enhanced approaches to treatment, prevention, and clinical surveillance