Rates of knee arthroplasty within one-year of undergoing arthroscopic partial meniscectomy in England: temporal trends, regional and age-group variation in conversion rates.

OBJECTIVE: The aim of this study was to determine the proportion of patients undergoing arthroscopic partial meniscectomy (APM) then subsequently receiving a knee arthroplasty within one or two years, with focus on patients over the age of 60 years and regional variation. METHODS: Patients undergoing APM in England over 20-years (01-April-1997 to 31-March 2017) were identified in the national Hospital Episode Statistics (HES). The proportion of patients undergoing arthroplasty in the same knee within one or two years of APM was determined and trends were analysed over time nationally and by NHS Clinical Commissioning Group (CCG) region. RESULTS: 806,195 APM patients were eligible for analysis with at least one-year of follow up and 746,630 with two-years. The odds of arthroplasty conversion within one year increased over the study period (odds ratio [OR] 3.10 within 1-year in 2014 vs 2000; 95% confidence interval [CI] 2.75-3.50). For patients undergoing APM aged 60 years or older in 2015-16, 9.9% (1689/17,043; 95% CI 9.5-10.4) underwent arthroplasty within 1-year and, in 2014-15, 16.6% (3100/18,734; 95% CI 16.0-17.1) underwent arthroplasty within 2-years. There was greater than 10-fold variation by CCG. CONCLUSIONS: Over the study period, the proportion of patients undergoing arthroplasty within one-year of APM increased. In 2015-16, of patients aged 60 years or older who underwent APM, 10% subsequently underwent knee arthroplasty within one year (17% within two years in 2014-15) and there was a high level of regional variation in this outcome. The development and adoption of national treatment guidance is recommended to improve and standardise treatment selection.