A study of population trends and future projections for the hip and knee arthroplasty service in the Republic of Ireland.

The incidence of elective total joint replacement of the hip and knee (THR and TKR respectively) is increasing with improved access to surgical care and an ageing population. We aimed to carry out a population level study of the incidence of elective primary total hip and knee arthroplasty between 2010 and 2019 and to estimate projected arthroplasty workload for the coming decades for the public orthopaedic service in the Republic of Ireland. In this retrospective population based observational study, data from the HIPE database was secured for all elective total hip and knee arthroplasties carried out in the republic of Ireland between 2010 and 2019. Population data for the same period was then collected from the Central statistics office dataset. Aggressive and conservative population estimates provided for the coming decades were used to calculate projected incidence/caseload of hip and knee arthroplasty surgery. Over 90 % of those undergoing arthroplasty in the studied period were aged >50. The average age of THR patients over the decade was 70 and that of TKR patients was 67. The incidence of patients aged under 50 undergoing these procedures has also increased over the decade. By 2036 numbers of total hip and knee arthroplasty are set to increase by up to 65 % and 49 % respectively. Waiting times for arthroplasty surgery in the public system are already among the longest in Europe. Significant investment in the arthroplasty service will be required to maintain the current level of service in the face of an increasing caseload.