Measuring Improvement Following Total Hip and Knee Arthroplasty Using Patient-Based Measures of Outcome

Abstract

The MODEMS, Oxford, and WOMAC scales all demonstrated a ceiling effect following total knee and total hip arthroplasty. These scores likely reflected the patients' perception of the status of the knee or hip rather than an inability to measure their improvement beyond the highest possible score. The Physical Component Summary score of the SF-36 had similar standardized response means when compared with hip and knee-specific instruments, and, therefore, consideration should be given to using this scale without a joint-specific scale for the measurement of improvement following total knee and total hip replacement, as a way to decrease responder burden (that is, the time required to complete the questionnaires).