Ultrasonographic Measurements of Paraspinal Muscle Thickness in Adolescent Idiopathic Scoliosis: A Comparison and Reliability Study

Purpose: To examine paraspinal muscle asymmetries in patients with mild adolescent idiopathic scoliosis (AIS) compared with controls using ultrasound (US) imaging and to determine reliability of the US imaging. Methods: Twenty adolescents (10 with and 10 without AIS) whose muscle thickness of the deep paraspinals at T8 and the multifidus at L1 and L4 vertebral levels was determined using US imaging. Results: Ultrasound imaging had good intrarater reliability (ICC_3,3 = 0.83-0.99) and interrater reliability (ICC_2,3 = 0.93-0.99). Significantly greater muscle thicknesses were found on the concave side at T8 and L1 compared with the corresponding convex side. Significantly greater normalized muscle thickness values were found on the concave side at T8, L1, and L4 in patients with mild AIS compared with controls. Conclusions: Ultrasound imaging is reliable for measuring the deep thoracic paraspinals and lumbar multifidus in adolescents with and without idiopathic scoliosis. Significant paraspinal muscle asymmetries were found in mild AIS. Video Abstract: For more insights from the authors, access Supplemental Digital Content 1, at http://links.lww.com/PPT/A76.