Abstract
Introduction and Aims: The importance in assessing clinical outcome is critical in evaluation of total hip replacement. There is now a sufficient body of evidence that activity level is correlated to wear of total hip replacement and wear to the longevity of that implant. The purpose of this study was, using the UCLA activity scale, to evaluate how activity relates to both health-related and disease-specific questionnaires.
Method: One hundred and fifty-two patients who underwent primary hip arthroplasty filled out the health-related questionnaire – SF-12 survey, which has a mental and physical component – with an average score of 50 in the general population for each category. The same day they were clinically evaluated, using the UCLA and Harris hip scoring systems. All patients were evaluated by the same surgeon; at least two years post-surgery, with an average follow-up of 5.2 years. Patient average age at surgery was 52.4, with 66% male. To assess the strength of the relationship between SF-12, UCLA and Harris scores, linear regression analysis was used.
Results: All individual UCLA scores were significantly correlated (p< 0.05) to SF-12 physical component, except for walking. When the single item UCLA activity score was added to Harris hip score, R squared raised from 0.43 to 0.53 in predicting quality of life. The single item Activity from the UCLA scoring system explained 38% of the variability in SF-12 physical component. With the linear regression analysis, all individual UCLA scores were independently significantly correlated (p< 0.05) to SF-12 physical component, except for walking. When the single item UCLA activity score was added to Harris hip score, R squared raised from 0.43 to 0.53 in predicting quality of life represented by the physical component of the SF-12.
Conclusion: Our study has shown that the UCLA activity scale is not only important to assess wear of the bearing surface, but also provides additional information in assessing the clinical outcome of total hip replacement. The single item Activity from the UCLA scoring system explained 38% of the variability in SF-12 physical component and demonstrates the need to integrate activity in outcome measurements after hip arthroplasty.
These abstracts were prepared by Editorial Secretary, George Sikorski. Correspondence should be addressed to Australian Orthopaedic Association, Ground Floor, The William Bland Centre, 229 Macquarie Street, Sydney, NSW 2000, Australia.
At least one of the authors is receiving or has received material benefits or support from a commercial source.
