Validation of a Novel Device for the Knee Monitoring of Orthopaedic Patients

Abstract

Fast-track surgery is becoming increasingly popular, whereas the monitoring of postoperative rehabilitation remains a matter of considerable debate. The aim of this study was to validate a newly developed wearable system intended to monitor knee function and mobility. A sensor system with a nine-degree-of-freedom (DOF) inertial measurement unit (IMU) was developed. Thirteen healthy volunteers performed five 10-meter walking trials with simultaneous sensor and motion capture data collection. The obtained kinematic waveforms were analysed using root mean square error (RMSE) and correlation coefficient (CC) calculations. The Bland–Altman method was used for the agreement of discrete parameters consisting of peak knee angles between systems. To test the reliability, 10 other subjects with sensors walked a track of 10 metres on two consecutive days. The Pearson CC was excellent for the walking data set between both systems (r = 0.96) and very good (r = 0.95) within the sensor system. The RMSE during walking was 5.17° between systems and 6.82° within sensor measurements. No significant differences were detected between the mean values observed, except for the extension angle during the stance phase (E1). Similar results were obtained for the repeatability test. Intra-class correlation coefficients (ICCs) between systems were excellent for the flexion angle during the swing phase (F1); good for the flexion angle during the stance phase (F2) and the re-extension angle, which was calculated by subtracting the extension angle at swing phase (E2) from F2; and moderate for the extension angle during the stance phase (E1), E2 and the range of motion (ROM). ICCs within the sensor measurements were good for the ROM, F2 and re-extension, and moderate for F1, E1 and E2. The study shows that the novel sensor system can record sagittal knee kinematics during walking in healthy subjects comparable to those of a motion capture system.

Smartphone App with an Accelerometer Enhances Patients’ Physical Activity Following Elective Orthopedic Surgery: A Pilot Study

“…Besides objective activity monitoring, Hospital Fit also provides patients insight into their recovery progress and offers physiotherapists the option of creating a patient-specific exercise program supported by videos. Recently, an increasing number of other mHealth tools have been investigated within the orthopedic rehabilitation pathway [28][29][30][63][64][65][66][67][68][69]. These tools are predominantly prescribed in support of outpatient physiotherapy.…”

A systematic review about telemedicine in orthopedics

“…2 Example of a video consultation with inspection of the knee joint consultation, therefore, has its limitations in the diagnosis of instabilities of the knee joint as well as shoulder diseases [2,7,32]. Perhaps new methods using the modern sensors can improve the possibilities for telemedicine for these areas in the future [17]. For example, a recent study showed that motion-based machine learning software has the potential to replace an examination knee within 5° after goniometer measurements remotely [29].…”

“…For example, a recent study showed that motion-based machine learning software has the potential to replace an examination knee within 5° after goniometer measurements remotely [29]. In the future, functional diagnostics over distances can also be possible on the knee with help of sensors [17,29].…”

“…One way to improve the precision of telemedical examinations and findings would be to use sensors, particularly in the context of rehabilitation [17,29]. Today, powerful motion sensors are so small that they can be attached locally to the knee and thus register movements.…”

Enhanced Recovery after Surgery for Knee Arthroplasty in the Era of COVID-19

“…The department is currently experimenting with knee sleeves that can be used to monitor postoperative range of motion remotely, providing surgeons with real-time information on the activity level and progress of patients. 48,49 ERAS for knee arthroplasty does not seem to be affected by the pandemic. In fact, the acceptance seems to be enhanced by it.…”