Sedentary behaviour after surgery is associated with delayed full return to work among patients receiving knee arthroplasty within the Back At work After Surgery (BAAS) work-integrated care cohort

Background: Sedentary behaviour and low physical activity may influence recovery after knee arthroplasty (KA) in working-age patients. This hypothesis-generating study investigates whether perioperative physical activity levels are associated with time to full return to work (RTW). Methods: Working-age patients (n = 121) in the multicentre BAAS cohort wore ankle accelerometers from 6 weeks pre- to 6 weeks post-surgery. Daily activity and sedentary episodes were analysed using generalised linear models with days to RTW as outcome. Results: Median RTW was 113 days (IQR 80–153). Preoperatively, each additional 10 min/day of moderate activity was associated with six fewer days to RTW (β = −0.63, 95% CI −1.1 to −0.1), while each additional minute of vigorous activity was associated with four more days days to RTW (β = 4.17, 95% CI 2.1–6.3). Additional sedentary episodes showed a borderline association with earlier RTW (β = −3.17, 95% CI −6.39 to 0.05). Postoperatively, each additional sedentary episode was associated with two more days to RTW (β = 2.31, 95% CI 0.2–4.4). Conclusions: Moderate preoperative activity was associated with earlier RTW, while vigorous pre- and postoperative sedentary behaviour was associated with delayed RTW. No other activity measures were associated with RTW.