Feasibility and Preliminary Outcomes of a Physical Therapist–Administered Physical Activity Intervention After Total Knee Replacement

Abstract

Objective. To explore the feasibility, fidelity, safety, and preliminary outcomes of a physical therapist-administered physical activity (PA) intervention after total knee replacement (TKR).Methods. 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.Results. 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/m 2 . 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.Conclusion. 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.ClinicalTrials.gov identifier: NCT02724137.

Current clinical utilisation of wearable motion sensors for the assessment of outcome following knee arthroplasty: a scoping review

“…Physical activity studies were consistent in the number of sensors implemented, with 21 studies (81%) using a single sensor for activity measurements 35–40 42 43 45–57. As technology and availability of wearable accelerometers has progressed, the type of sensor used has also changed.…”

“…In studies published between 2008 and 2016, nine studies (69%)36 37 40 42 44 45 58–60 reported using a uniaxial accelerometer versus just three studies (23%)46 55 56 using a triaxial accelerometer. Conversely, in studies published in 2017–2019, eight studies (62%)35 38 47 49 50 53 54 57 reported using a triaxial accelerometer, while only three (23%)39 43 45 used a uniaxial accelerometer. Overall, three studies did not report the number of axes recorded,41 48 51 and most studies within this subgroup (73%)36 37 40–45 47 48 50–55 57 60 did not report the sampling rate at which data were collected.…”

“…Conversely, in studies published in 2017–2019, eight studies (62%)35 38 47 49 50 53 54 57 reported using a triaxial accelerometer, while only three (23%)39 43 45 used a uniaxial accelerometer. Overall, three studies did not report the number of axes recorded,41 48 51 and most studies within this subgroup (73%)36 37 40–45 47 48 50–55 57 60 did not report the sampling rate at which data were collected. No standard frequency was observed within studies reporting sampling rate, as two studies collected data at 10 Hz,39 56 two at or near 30 Hz49 58 and three at 100 Hz 35 38 46.…”

“…No standard frequency was observed within studies reporting sampling rate, as two studies collected data at 10 Hz,39 56 two at or near 30 Hz49 58 and three at 100 Hz 35 38 46. Accelerometers were mounted at hip or waist level, most commonly with an elastic strap, in half of the included physical activity studies 36–38 42 43 45–47 49 50 53 56 58. Seven studies positioned sensors on the thigh,35 39 41 44 48 58 60 four on the sternum,41 44 59 60 four on the lower leg,40 52 54 59 one on the foot59 and two on the wrist 51 57…”

“…All studies within this subgroup quantified physical activity based on free-living activity. Most commonly, free-living data was collected in 7-day sessions (13 studies, 50%),36–39 42 45–47 49 50 53 57 58 with 10 studies (43%)35 40 41 44 48 52 54 58–60 collecting data over shorter sessions (eg, 2–4 days). Four studies reported longitudinal activity metrics for longer time periods, with Hayashi et al 43 and Tsuji et al 56 reporting physical activity during post-operative hospitalisation for 8 and 14 days, respectively, while Luna et al 51 reported basic accelerometer counts for 20 days post-operatively and Taniguchi et al 55 asked patients maintain a daily step count log for 6 months following surgery.…”