Wearable sensor assists in rehabilitation after knee replacement

Patients who have received knee replacement operations may benefit from using BPMpathway, a wearable sensor that leads to high range of motion and exercise compliance while also reducing face-to-face physiotherapy sessions, according to a recent study.

Such an impact contributes to the high rates of device acceptability among users. “The vast majority of participants who completed the questionnaire stated that they enjoyed using the device, were able to use it independently, and were motivated to continue with their rehabilitation,” the researchers said.

Twenty-one patients (mean age 57.76 years, 57 percent men) participated in the study and were given the wearable sensor during the joint school session prior to surgery. The device was worn for up to 9 weeks after surgery and allowed researchers and doctors to remotely monitor the participants’ progress and exercise and provide a two-way communication channel between patients and clinicians. Training regimens were altered as required.

The present analysis included a total of 1,163 days of BPMpathway use, comprised of 426 days of preoperative device use and 737 days of postoperative rehabilitation. Overall, participants performed range-of-motion exercises 1,179 times over 1,163 study days, during which time patient compliance was 32.34 percent and 52.4 percent for thrice- and once-daily exercise, respectively. [JB JS Open Access 2022;7:e21.00154]

Range of motion also improved over time with device use, increasing from 63° during the first postoperative week to 109° at week 4 and 136° at week 7.

Of note, not all participants continued remote rehabilitation over the 6-week study period and terminated exercises after a mean of 32 days. Nevertheless, the final median range of motion was 129° when exercise was stopped. In both pre- and postoperative phases, greater compliance to thrice- and once-daily exercises both correlated significantly with better final-day range of motion (p≤0.01).

Flexion likewise significantly improved over time and with better exercise compliance both in the pre- and postoperative periods.

Moreover, using the BPMpathway device led to a 35.7-percent drop in face-to-face physiotherapy sessions. Only 81 visits (11 outpatient, 70 at-home) were required during the duration of the study, as opposed to the scheduled 126 sessions when the wearable sensor was not in use.

Participants had largely favourable opinions of the device, with 93.75 percent and 81.25 percent agreeing that the app was easy to download and that they liked the range-of-motion sensor, respectively. Similarly, more than 80 percent of patients easily understood how to perform the rehabilitation exercise and said that the sensor motivated them to perform the exercises.

“Because of the pilot nature of this study, it was not designed to address any specific clinical questions. In addition, no control group was incorporated into the experimental design, limiting the interpretation of this work,” the researchers said.

“Future adequately powered, two-arm studies that incorporate BPMpathway into the intervention arm are needed to assess the impact that BPMpathway may have on clinical and patient-reported outcomes,” they added.