WHERE Study: Waiting for Hip or knEe REplacement: A prospective cohort

Total hip and knee replacements (TJR) for osteoarthritis are common orthopaedic procedures performed in Canada. Waits for these procedures are already lengthy, and the COVID-19 pandemic has further delayed thousands of scheduled TJRs. Longer wait times for TJR can be associated with increased pain and functional disability, and up to 80% of patients awaiting TJR use opioids for pain management. Further, some studies show that certain minority or disadvantaged groups may be more likely to wait longer and report worse pre-operative symptoms. Moreover, worse pre-operative symptoms and opioid use have been linked to poor recovery and continued opioid abuse post-operatively. Interestingly, some clinical studies have shown that not all patients experience a deterioration in symptoms while on the waitlist for TJR, and a longer wait time is not always associated with poor post-operative outcomes. However, there is insufficient evidence surrounding the relationships between wait time, patient characteristics, and outcomes both prior to and following TJR. We aim to establish a large prospective cohort of patients with osteoarthritis waiting for TJR with key research questions and the overarching objectives of identifying which patients are most affected by longer waits, and which patients may tolerate longer wait times. We will enroll 2,070 patients awaiting TJR in Ontario, Canada, and follow the patients from their waitlist enrolment up to two years post-operatively. During this time, we will collect pain, function, opioid use, and quality of life measures at regular intervals. In addition, we will conduct an economic analysis to determine the impact of length of time on a waitlist on patient and healthcare system costs, and whether this varies for certain subgroups of patients. The data will highlight the consequences of long waits for patients undergoing TJR, information that will improve patient care and provide insight for refining wait list policies.