Patient Relevant Outcomes after total hip replacement. A comparison between different surgical techniques

OBJECTIVE To investigate differences in pre- and postoperative patient-relevant outcome between hybrid total hip replacement (THR) and cemented THR in patients with primary osteoarthritis (OA). METHODS 245 consecutive patients were included in the study. 68 of the patients (mean age 62) were operated on with hybrid THR and 177 (mean age 74) were operated on with cemented THR. All patients were investigated preoperatively and 0.5, 1 and 3.6 years postoperatively with two self-administered questionnaires, SF-36 and WOMAC (Western Ontario and MacMaster Universities Osteoarthritis Index, LK 3.0). RESULTS Preoperatively, there was a difference in the SF-36 subscales RP (role physical) and GH (general health) where the patients with the hybrid THR attained better scores. At 3.6-years the patients with the hybrid THR reached better scores in all SF-36 subscales except BP (bodily pain) and GH. Further, they had better scores in WOMAC function. However, after adjusting for age, sex, follow-up time and baseline values there were no differences in outcome between the two different surgical techniques. CONCLUSION This medium term (3-5 years), controlled, open cohort study, using patient-relevant outcome measures, did not reveal any differences between hybrid THR and cemented THR for OA at 3.6 years after surgery. Since the study had 75-94% power to detect the clinically significant score difference of 10 points, we suggest that any difference in outcome between these two methods is small and may require a large-scale, blinded, randomized trial to show.