Reliability of Spinal Flexibility Measurement on Ultrasound Images

Abstract

Scoliosis is a three-dimensional deformity of spine with vertebral rotation. Brace treatment is the most effective non-surgical treatment for scoliosis. Spinal flexibility affects the amount of correction attainable by bracing. More flexible spines should be more correctable in a brace. However, lateral-bending radiographs are generally not required for brace patients in order to minimize exposure to undesirable ionizing radiation. Without knowing the spinal flexibility, orthotist usually designs the brace based solely on empirical knowledge derived from personal experiences. Ultrasound imaging method has been used to measure the spinal curvature reliably. The objective of this study was to determine the accuracy of the curve flexibility measurements on the ultrasound images. Twelve children who have adolescent idiopathic scoliosis and required brace treatment were recruited. Standing radiographs and prone side-bending ultrasound images were acquired. A total of 20 curvatures were measured and compared between 2 raters. The intra- and inter-rater reliablities of the flexibility measurements were (R1: 0.96; R2: 0.95) and 0.91, respectively. There was no statistically significant difference between the measurements from the 2 raters. However, since the number of participants is still small, more trials are required before making a definite conclusion.