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.