Physical activity levels two years after total knee arthroplasty and preoperative patient characteristics: a secondary analysis of the MOVE randomized controlled trial
In brief
About half of knee replacement patients return to preoperative activity levels
Two years after knee replacement, 53% to 56% of patients had returned to their preoperative levels of light activity, moderate-to-vigorous activity, or daily steps, even as average steps rose 8%. Those who were more active before surgery were less likely to match their baseline levels afterward, suggesting rehabilitation may need more tailored support to address activity goals.
- Journal
- The Journal of arthroplasty (Q1)
- Published
- 23 October 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Nina M Carson, Kristen I Barton, Jacob J Capin, Jeri Forster, Jason Jennings, Michael Dayton, et al.
- PMID
- 42918273
- DOI
- 10.1016/j.arth.2026.10.012
Why clinicians should know about it
- Picked for Orthopedics and Sports Medicine (top studies of the week, 1 November 2026): Physical activity recovery trajectories after total knee arthroplasty
Abstract
INTRODUCTION: At one year after total knee arthroplasty (TKA), patients are less physically active than age-matched peers, but physical activity (PA) trajectories two years after TKA are unclear. This study examined PA levels from baseline to two years post-TKA, quantified return to baseline PA levels over time, and evaluated associations between baseline participant characteristics and post-TKA PA levels. METHODS: This was an exploratory secondary analysis of a randomized controlled trial. Participants (n = 135) aged 50 to 85 years undergoing primary unilateral TKA wore accelerometers preoperatively and 10 weeks, six months, and two years post-TKA to characterize light PA, moderate-vigorous PA (MVPA), and steps/day. Descriptive statistics were used to characterize PA levels. Repeated measures models estimated PA levels over time. The percentage of participants who returned to or exceeded baseline PA levels over time was quantified. Multivariate logistic regressions modeled return to baseline PA levels over time to evaluate associations with baseline participant characteristics. All models controlled for age, sex, and treatment group. RESULTS: There was an increase of 8% steps/day and 0.75% MVPA from baseline to two years post-TKA. At two years post-TKA, 54.2, 53.1, and 55.6% of participants returned to baseline light PA, MVPA, and steps/day levels. Higher baseline PA levels were associated with lower odds of returning to baseline levels at all timepoints for MVPA (10 weeks odds ratio (95% confidence interval): 0.62 (0.46 to 0.84); six months: 0.55 (0.40 to 0.76); two years: 0.52 (0.36 to 0.75)), as well as light PA and steps/day (all P-values < 0.05). Baseline body mass index, Western Ontario and McMaster Universities Arthritis Index scores, and Functional Comorbidity Index were associated inconsistently with PA levels. CONCLUSION: While on average, PA levels increased from baseline to two years post-TKA, participants who have higher baseline PA levels had reduced odds of returning to the same level. These findings suggest TKA and current rehabilitation may not fully address PA, and additional support (e.g., behavioral guidance or tailored rehabilitation) may be needed.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.