Wearable sensor-based measures of step-up transfers are supplementary to patient-reported outcome measures following total joint arthroplasty

Abstract

Purpose

This study investigated the longitudinal assessment of step-up performance in patients undergoing total joint arthroplasty (TJA) and correlation with subjective patient reported outcome measures (PROMs).

Methods

In this sub-analysis of the ADAPT study, PROMs were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Block step-up (BS) transfers were assessed by wearable-derived measures of time. 76 patients undergoing TJA were included. Subgroups were formed isolating the worst performing quartile (low functioning (LF)) from the high functioning (HF), and outcomes were compared–

Results

One-year post-surgery, WOMAC function demonstrated strong correlations to WOMAC pain (Pearson’s r = 0.67–0.84) and moderate correlations to BS performance (Pearson’s r = 0.31–0.54). Both WOMAC and BS significantly improved with a larger effect size for the HF subgroup (0.62 vs. 0.43; p < 0.05). Patients designated to the LF subgroup at 3 months had increased odds of representing the LF subgroup at 12 months (WOMAC = 19; BS = 4). WOMAC defined 18 LF patients at 12 months follow-up. BS performance identified 9 additional LF patients.

Conclusions

WOMAC function scores seem pain dominated. Measures of BS performance allow assessment of otherwise hidden residual functional impairment. Lower functioning 3 months post-surgery is predictive of longer-term impairment.

Implications for rehabilitation

• Severe hip or knee osteoarthritis is a disabling condition which not only impacts patients’ mobility but restricts quality of life due to constant pain and consequential lifestyle changes.

• Total joint arthroplasty (TJA) has developed into a successful intervention for patients with advanced hip or knee osteoarthritis.

• Some patients are dissatisfied after TJA due to residual functional impairment and the inclusion of performance-based tests in the post-operative evaluation and rehabilitation allows for the assessment of otherwise hidden residual impairment.

• Early detection of functional impairment using the repeated block step-up (BS) transfers allows to facilitate more targeted rehabilitation for better functional outcomes.

Keywords:

• Arthroplasty
• outcome assessment
• performance-based test
• patient reported outcome measures
• WOMAC

Acknowledgements

This work was supported by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research programme (RP-PG-0407-1070). The views expressed in this article are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. The research team acknowledges the support of the NIHR, through the Comprehensive Clinical Research Network.

Author contributions

All authors were involved in the design. NP performed the data extraction. NP and EL performed the data analyses. All authors reviewed and edited the manuscript.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

The data that support the findings of this study are available from the corresponding author [N.H.M. Ponds], upon reasonable request.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.