Determinants of 6-12 month postoperative functional status and pain after elective total hip replacement

Abstract

Objective: The goal of this pilot project was to quantify outcomes of elective total hip replacement through risk adjustment modeling.

Design: A retrospective cohort study of patients who underwent elective total hip replacement (THR) during 1991 at the Orthopaedic and Arthritic Hospital in Toronto.

Study participants: All patients undergoing elective total hip replacement with a confirmed diagnosis of osteoarthritis were asked to participate in the study; 193 patients agreed.

Outcome measures: Participants were asked to complete the WOMAC Osteoarthritis Index and the RAND 36-item Health Survey 6 months to 1 year post-operatively. Pre-operative information on pain and functional status was obtained from the patients' medical record.

Results: The results indicate that 93% of patients studied reported at least one significant co-morbidity. The mean pre-operative pain score was 7.5 on a 0-10 scale and average change in pain was 4.8. Regression analyses indicate that increased body mass index is associated with lower post-operative functional status and increased post-operative pain. The amount of pain relief the patient was able to obtain pre-operatively using non-surgical interventions was associated with a better outcome.