Effectiveness of a Physical Therapist-Administered Physical Activity Intervention after Total Knee Replacement: A Randomized Trial

Importance While total knee replacement (TKR) is the definitive treatment for knee osteoarthritis, physical activity remains unchanged after surgery. Objective The objective of this trial was to examine the efficacy of a physical therapist-administered physical activity intervention to increase moderate-to-vigorous physical activity (MVPA) over 6 months for adults after TKR. Design This was a randomized controlled trial. Setting The study took place in an outpatient physical therapist clinic. Participants Included were 120 adults over the age of 45 years seeking outpatient physical therapy following a unilateral TKR. Interventions Participants received standardized physical therapy after TKR and a wearable activity tracking device, individualized step goals, and face-to-face feedback provided by a physical therapist (intervention), or standardized physical therapy alone (control). Main Outcome and Measure The primary outcome was change in MVPA recorded by a hip-worn Actigraph GT3X accelerometer from baseline to 6 months after discharge from physical therapy. Results MVPA similarly increased from baseline to 6 months within the intervention (median = 6.0 minutes per day [semi-interquartile range = 11.9]) and control group (median = 5.9 minutes per day [semi-interquartile range = 14.3]). There was no between-group difference in MVPA change over time. Conclusion A physical therapist-administered physical activity intervention resulted in a similar increase in MVPA over 6 months compared to standardized physical therapy for adults after TKR. Relevance Adding a wearable activity tracking device and individualized step goals may not increase physical activity for adults after TKR receiving outpatient physical therapy.