Feasibility and Preliminary Outcomes of a Physical Therapist-Administered Physical Activity Intervention After Total...

To explore the feasibility, fidelity, safety, and preliminary outcomes of a physical therapist-administered physical activity (PA) intervention after total knee replacement (TKR).

People who had undergone a unilateral TKR and were receiving outpatient physical therapy (PT) were randomized to a control or intervention group. Both groups received standard PT for TKR. The intervention included being provided with a Fitbit Zip, step goals, and 1 phone call a month for 6 months after discharge from PT. Feasibility was measured by rates of recruitment and retention, safety was measured by the frequency of adverse events, and fidelity was measured by adherence to the weekly steps/day goal created by the physical therapist and participant monitoring of steps/day. An Actigraph GT3X measured PA, which was quantified as steps/day and minutes/week of engaging in moderate-to-vigorous PA. Our preliminary outcome was the difference in PA 6 months after discharge from PT between the control and intervention groups.

Of the 43 individuals who were enrolled, 53.4% were women, the mean ± SD age was 67.0 ± 7.0 years, and the mean ± SD body mass index was 31.5 ± 5.9 kg/m² . For both the control and intervention groups, the recruitment and retention rates were 64% and 83.7%, respectively, and adherence to the intervention ranged from 45% to 60%. No study-related adverse events occurred. The patients in the intervention group accumulated a mean 1,798 more steps/day (95% confidence interval [95% CI] 240, 3,355) and spent 73.4 more minutes/week (95% CI -14.1, 160.9) engaging in moderate-to-vigorous PA at 6 months than those in the control group.

A physical therapist-administered PA intervention is feasible and safe, demonstrates treatment fidelity, and may increase PA after TKR. Future research is needed to establish the effectiveness of the intervention.