Pre-operative expectation predicts 12-month post-operative outcome among patients undergoing primary total hip replacement in European orthopaedic centres

Objective: Patients' expectations of surgery may be related to outcomes of joint replacement. The aims of this study were to: (1). Identify patient characteristics associated with pre-operative expectations of total hip replacement (THR); (2). Explore whether pre-operative expectations predict surgical outcomes 12-months post-THR.

Method: The European collaborative database of cost and practice patterns of THR (EUROHIP) study consists of 1327 consenting patients coming to primary THR for osteoarthritis (OA) across 20 European orthopaedic centres. Ordered logistic regression modelling was used to look at the association between patients pre-operative expectations and baseline characteristics (age, sex, education, American Society of Anaesthesiologists (ASA) status, Kellgren & Lawrence (K&L) grade, body mass index (BMI), medication use, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score, EQ5D (EuroQol) score). The Outcome Measures in Rheumatology (OMERACT)/Osteoarthritis Research Society International (OARSI) responder criteria were used to classify patients as improved/not improved 12-months post-THR. Logistic regression modelling was used to explore whether pre-operative expectations predict response to THR.

Results: Greater numbers of pre-operative expectations were associated with younger age, women, increasing BMI, and more education. The more pre-operative expectations a patient had, the more likely they were to improve after surgery. Each individual expectation a patient had, was associated with a 34% increase in improvement [95% confidential interval (CI) 1%-78%]. Analyses within dimensions of the WOMAC suggest the association is strongest for stiffness and function.

Conclusion: There is large variation in patients' pre-operative expectations of THR. Greater numbers of pre-operative expectations were associated with improvement following THR. This appears to be driven more by stiffness and function. These findings have implications for informed patient-clinician decision-making.