ABSTRACT
INTRODUCTION: Diagnostic accuracy is one of the key considerations of telemedicine usage in orthopedic surgery. The aim of this study was to determine the optimal patient positioning to achieve accurate and reliable visual estimation of the knee joint range of motion over a digital platform for telemedicine. METHODS: A single volunteer was recruited to perform a total of 120 discrete and random knee range of motion angles in three patient positions: sitting, standing and supine. The patient image was broadcast over a digital platform to six raters. The raters recorded their visual estimation of each discrete knee flexion angle independently. After each discrete knee flexion angle, a physical goniometer was used to obtain the actual flexion angle of the knee. RESULTS: A total of 120 discrete measurements (40 measurements in the sitting, standing, and supine positions each) were recorded by each of the six raters. The supine position resulted in the highest intraclass correlation of 0.97 (95% confidence interval: 0.98, 0.99). All three patient positions achieved low absolute difference between the goniometer and the raters with 5.6 degrees (95% limits of agreement: -21.0, 9.8) in sitting, 2.7 degrees (95% limits of agreement: -10.1, 15.4), and 1.2 degrees (95% limits of agreement: -9.8, 12.3) in the supine position. The supine position had the highest accuracy and reliability. DISCUSSION: Visual estimation of the knee joint range of motion over telemedicine is clinically accurate and reliable. Patients should be assessed in a supine position to obtain the highest accuracy and reliability for visual estimation of the knee joint range of motion during telemedicine.
