The impact of preoperative function and pain on early patient-centred outcome after total hip arthroplasty

Aim: It was the purpose of this prospective study to investigate the impact of preoperative functional status and pain on the early patient-centred outcome after total hip arthroplasty (THA). Methods: 67 consecutive patients scheduled for THA were included in this study. Outcome was analysed with the Western Ontario and McMaster Universities' (WOMAC) Osteoarthritis Index preoperatively and after ten days and 12 weeks, respectively. Patients were grouped with regard to their preoperative function and pain according to the WOMAC Osteoarthritis Index. Statistical analysis was performed using a multivariate regression model considering further confounding variables (age, gender, affected side, duration of surgery, and anchorage of THA). Results: All patients showed a significant functional improvement both at ten days postoperatively and after three months, respectively. Patients with a higher degree of disability preoperatively had a larger relative functional improvement according to their WOMAC score compared to patients who initially were less deteriorated. However, the latter had the better absolute scores postoperatively. Multiple regression analysis revealed gender (OR: - 11.85, 95% Cl: - 22.65 to - 1.06, p = 0.03) and preoperative WOMAC score (OR: 0.34, 95% Cl: 0.09 to 0.59, p < 0.01) to be significant prognostic Variables at ten days postoperatively. After three months, age (OR: 0.43, 95 % CI: 0.04 to 0.82, p = 0.03) was the only variable predicting the patient-centred outcome. Conclusion: In our study sample, patient-related variables did significantly influence the patient-centred outcome after ten days (gender and WOMAC) and at three months postoperatively (age) whereas procedure-related variables did not have any impact.