Future demand for primary hip and knee arthroplasty in Scotland

Introduction: The rising prevalence of osteoarthritis, associated with an ageing population, is expected to deliver increasing demand for arthroplasty services in the future. Understanding the scale of potential change is essential to ensure adequate provision of services and prevent prolonged waiting times that can cause patient harm. 

Methods: We set out to provide projections of future primary knee and hip arthroplasty out to 2038 utilising historical trend data (2008–2018) from the Scottish Arthroplasty Project. All analyses were performed using the Holt's exponential smoothing projection method with the forecast package in R statistics. Results were adjusted for projected future population estimates provided by National Records of Scotland. Independent age group predictions were also performed. 

Results: The predicted rise of primary hip arthroplasty for all ages is from 120/100k/year in 2018 to 152/100k/year in 2038, a 28% increase. The predicted rise of primary knee arthroplasty for all ages is from 164/100k/year in 2018 to 220/100k/year in 2038, a 34% increase. Based on a static 3-day length of stay average this would see 4280 and 7392 additional patient bed days required for primary hip and knee arthroplasty patients respectively per annum. The associated additional cost is anticipated to be approximately £26 million. 

Conclusions: Anticipated future demand for arthroplasty will require significant additional resource and funding to prevent deterioration in quality of care and an increase in patient wait times, additional to that already required to clear the COVID-19 backlog. Understanding presented projections of changes to arthroplasty demand is key to future service delivery.