Reliability on evaluation of quadriceps femoris muscle quality by ultrasonic echo intensity in patients with knee osteoarthritis / 中国康复理论与实践

ABSTRACT

ObjectiveTo evaluate the inter-rater and test-retest reliability of echo intensity of ultrasound image for quality of quadriceps femoris in patients with knee osteoarthritis (KOA). MethodsFrom March to December, 2021, 33 patients with unilateral KOA in Guangdong Provincial Second Hospital of Traditional Chinese Medicine were included. Ultrasound was used to observe the cross sections of rectus femoris (RF), vastus medialis (VM) and vastus lateralis (VL), and the images were saved. Two independent raters analyzed the average gray value of the picture with the Image J. One of the raters repeated the measurement. The intra-class correlation coefficient (ICC), standard error of measurement (SEM), minimum detectable change (MDC) and coefficient of variation (CV) were calculated and the Bland-Altman charts were drawn. ResultsThe gray value was higher in the RF, VM and VL in the affected side than in the healthy side (t > 2.262, P < 0.05). The inter-rater reliability was excellent, with ICC 0.982 to 0.995, SEM 1.60 to 3.82, CV 1.49% to 5.90%, and MDC value 4.43 to 10.59. The test-retest reliability of the rater was excellent, with ICC 0.969 to 0.990, SEM 2.37 to 5.41, CV 2.22% to 4.84%, and MDC value 6.57 to 15.00. Bland-Altman charts analysis showed that the consistency was good. ConclusionThe quadriceps femoris muscle quality is different between the affected and the healthy sides in patients with unilateral KOA. It is reliable to evaluate muscle echo intensity by Image J.