The purpose of this study was to establish a model to predict the future need for total hip and knee replacement surgery over the next ten years.

Analysis based on queuing theory and Ontario data (Ontario Joint Replacement Registry) considered such factors as changing demographics, specific wait time objectives and changing indicators to predict the future need for THR and TKR up to 2015.

26 725 Ontarians were waiting for THR and TKR surgery on any given day in 2004–05. Each month, the number of new decisions for surgery exceeded the actual number of surgeries by over 20%, adding another five hundred patients to the wait list. We predict that the population > fifty-five years of age will increase by 3.4% annually and that the willingness of patients to consider TJR surgery will increase by 8.7%/year To reduce wait times and establish a steady state of waiting (less than 6 months wait), more than 50 000 surgeries per year must be provided within five years and 70 000 total joint replacements per year by 2014–15 as compared to the 31 448 performed annually at this time. Providing this volume of surgeries means that the number of surgeons will have to double within five to seven years.

The results of this queuing theory analysis predict a substantial need for markedly increased THR and TKR volumes and orthopaedic manpower over the next decade.