Gait analysis and WOMAC are complementary in assessing functional outcome in total hip replacement

OBJECTIVE: To investigate the correlation between objective and subjective evaluation of patients with total hip replacement. DESIGN: Prospective preliminary trial comparing the Western Ontario and McMaster University questionnaire (WOMAC) and gait analysis preoperatively and three months postoperatively. SETTING: A German academic orthopaedic centre specializing in total hip replacement surgery. SUBJECTS: Seventeen patients (median age 70 years) with hip osteoarthritis. Intervention: All patients had had a primary unilateral total hip replacement. MAIN MEASURES: WOMAC questionnaire to assess self-perceived health status and gait analysis to determine objective gait parameters. RESULTS: Performance of walking as well as subjective judgement of health status improved following surgery (gait speed P = 0.0222; stride length P = 0.038; stance phase ratio P = 0.0466; WOMAC P < 0.0001). However, the correlation between gait parameters and WOMAC was poor (r = -0.27 or less). Correlation between changes of walking parameters and WOMAC was bad to good (r = 0.01 to r = -0.72). CONCLUSION: The WOMAC questionnaire might not reflect walking performance. The addition of gait analysis is recommended to gain objective information about the quality of gait.