Abstract
This study explored differences in the early pattern of recovery for self-report (pain and physical function subscales of the Western Ontario and McMaster Universities Osteoarthritis Index) and physical performance measures (six minute walk and timed up and go test) in patients following arthroplasty. Using hierarchical linear modeling, different patterns of recovery and predictors of change were observed. The physical function subscale did not detect the early deterioration in physical function that was detected by the performance measures. Different important clinical information can be learned from performance measures, supporting the use of both types of measures when monitoring decline and recovery.
To explore differences in the pattern of recovery for self-report and physical performance measures in patients following total hip (THA) and knee (TKA) arthroplasty.
Different patterns of recovery and predictors of change were observed for the pain and physical function subscales of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the performance measures. The physical function subscale did not detect the early deterioration in physical function demonstrated by the six minute walk (6MWT) and timed up and go (TUG) tests.
WOMAC scores are commonly used to monitor changes in pain and physical function both pre and post-operatively. Failure of the physical function sub-scale to detect decline in physical function experienced post-operatively suggests that the WOMAC may not always accurately reflect physical function.
The postoperative predicted scores for the WOMAC either exceeded or met the preoperative scores within one to two weeks compared to seven to eight weeks with the performance measures. The performance measure models contained a greater number of predictors than the WOMAC subscale models.
One hundred and fifty-two patients (mean age 63.8 ± 10.2 years) who underwent THA and TKA were assessed at several points over the first four postoperative months. Average growth curves for the WOMAC, 6MWT and TUG were characterized using hierarchical linear modeling. Predictors of recovery were sequentially modeled after validation of the basic developmental models.
Differences in models and the time point at which preoperative scores are met suggest that different information is being learned from self-report and physical performance measures.
Funding: This research was not supported by funding from a commercial party. It was supported by a grant from the Orthopaedic & Arthritic Foundation.
Correspondence should be addressed to Cynthia Vezina, Communications Manager, COA, 4150-360 Ste. Catherine St. West, Westmount, QC H3Z 2Y5, Canada
