Long-term Impacts of Brace Treatment for Adolescent Idiopathic Scoliosis on Body Composition, Paraspinal Muscle Morphology, and Bone Mineral Density

Study Design. A retrospective, long-term follow-up study. Objective. We aimed to investigate the long-term impacts of brace treatment for adolescent idiopathic scoliosis (AIS) on the musculoskeletal system. Summary of Background Data. Although full-time brace treatment is the mainstay of conservative treatment for AIS, the restrictive nature of brace treatment for lumbosacral motion might negatively affect the musculoskeletal system. Methods. Of 319 patients treated nonoperatively for AIS, 80 patients completed clinical and imaging examinations. Body composition, including body fat mass, lean mass, fat percent, and muscle mass, was estimated via bioelectrical impedance analysis. Bone mineral density (BMD) was measured at the lumbar spine and left hip. In 73 patients, the measurement of cross-sectional area and fatty degeneration of paraspinal muscles at the superior endplate of L4 were performed using axial T2-weighted magnetic resonance imaging. Patients were divided into the full-time brace (FB; >13 hours per day) and nonfull-time brace (NFB; observation, part-time bracing, or drop out from FB within a year) groups. Results. There were 44 patients in the FB group and 36 in the NFB group. Patients in the FB group were significantly younger at the initial visit (12.7 ± 1.3 years) and older at the final follow-up (41.5 ± 5.6 years) than those in the NFB group (14.2 ± 3.2 and 37.4 ± 7.1 years, respectively; P < 0.01). The rate of patients engaging in mild or moderate sports activity in adulthood tended to be higher in the FB group (47.7%) than in the NFB group (25%) ( P = 0.11). However, there were no significant differences in body composition, paraspinal muscle morphology, and BMD between the two groups both before and after adjusting for age. Conclusion. Full-time brace wearing during adolescence did not have any negative impacts on the musculoskeletal system in adulthood. This information will be helpful for improving the compliance of full-time bracing. Level of Evidence: 4