Does bracing affect bone density in adolescent scoliosis?

Abstract

This is a case-control, cross-sectional analysis of bone density. To determine if bracing during growth affects bone density in adolescent idiopathic scoliosis and whether the effect is local or systemic. Data concerning the effect of bracing on bone mass in adolescents with idiopathic scoliosis are nonexistent. We were concerned that bone mass loss resulting from long-term brace use may be permanent and may predispose to problems with osteoporosis. Healthy adolescent females (n = 85) with scoliosis measuring 20-45 degrees and treated either by brace or observation were studied. Dietary calcium, activity level, body mass index, and pubertal status were evaluated. Scoliosis was measured by Cobb angle. Bone mineral density at the hip and spine were measured by dual energy x-ray absorptiometry to differentiate local versus systemic effects of bracing. Lateral scans of the L3 vertebral body were used to minimize the influence of the pedicles, the effect of the scoliosis, and the interference of the ilium. Mean age, height, and weight were similar between braced and observed groups. After adjusting for curve, Cobb angle, body mass index, activity, and diet, two-way analysis of covariance showed L3 and femoral bone mineral density was the same for braced and observed patients, and pubertal status affected spinal bone mineral density but had no effect on femoral bone mineral density. Pubertal status and body mass index accounted for 53% of the variation in spine bone mineral density and was not affected by brace use. Cobb angle, curve pattern, activity, and diet were not associated with bone mineral density. Brace treatment does not adversely affect bone mass at the spine and hip in children with idiopathic scoliosis.