Promoting physical activity via physical therapist following knee replacement: A pilot randomized controlled trial

Abstract

Background: Outpatient physical therapy may be an opportune time to promote aerobic physical activity after knee replacement; however, it is unknown if it is feasible to integrate a physical activity intervention within standard physical therapy.

Objective: To examine the feasibility and acceptability of a physical activity intervention delivered within outpatient physical therapy for adults after knee replacement.

Methods: As part of a cluster randomized trial, adults with knee replacement starting outpatient physical therapy were recruited across four physical therapy sites. Sites were randomized and physical therapists delivered either an enhanced physical activity intervention or a control condition. The enhanced physical activity intervention consisted of standard postoperative physical therapy plus goal setting, problem-solving, and use of motivational interviewing techniques to promote 150 minutes/week of aerobic moderate intensity physical activity. The control group received standard postoperative physical therapy only. Feasibility and acceptability were determined based on recruitment and retention rates at 12 weeks after surgery. Outcomes including objectively measured physical activity, pain, and self-reported function were examined at the baseline postoperative visit and 12 weeks later.

Results: Thirty-three percent of candidates screened were randomized (n = 45) and retention at 12 weeks after surgery was 91% (no difference by condition). Moderate-intensity activity increased, pain decreased, and self-reported function improved, but there were no statistically significant group differences between baseline and 12 weeks.

Conclusion: Implementing a physical activity intervention within outpatient physical therapy for adults after knee replacement is feasible; however, in this pilot study, changes were not observed in moderate intensity physical activity as compared to standard postoperative physical therapy. Future studies are needed to explore additional low-cost strategies and the optimal time to promote physical activity after knee replacement.

Trial registration: ClinicalTrials.gov NCT03768206.