Preliminary design of an underarm brace for improving cobb angle reduction in adolescent idiopathic scoliosis: A case report

Abstract

Adolescent idiopathic scoliosis (AIS) is a condition commonly found in teenagers. The treatment depends on the severity of the curvature and the patient’s skeletal maturity. Brace treatment is a successful conservative method for preventing curve progression. Various brace designs are available, with the underarm brace based on Boston principles being a common choice at a teaching hospital in Thailand. According to the Boston principles, a window is provided contralateral to the thoracic curve; however, no specifications regarding window opening in the lumbar area are mentioned. This study aimed to investigate the impact of a modified underarm brace with openings on in-brace Cobb angle reduction, coronal decompensation, and apical vertebral translation, compared to a conventional underarm brace without openings. Two participants were fitted with two types of underarm braces: one without openings (D1) and one with openings on the contralateral thoracic and lumbar areas (D2). Thoracic Cobb angle (TCA), lumbar Cobb angle (LCA), coronal decompensation (CD), thoracic apical vertebral translation (TAVT), and lumbar apical vertebral translation (LAVT) were measured for both designs and compared to baseline measurements. Additionally, patient satisfaction and feedback were collected. Results indicated that Cobb angle reduction for both thoracic and lumbar regions was superior with D2 compared to D1 for both cases. However, no significant changes were observed in CD, TAVT, or LAVT. Patient satisfaction was higher with D2, except regarding ease of donning and breathing.