Effects of thoracolumbosacral orthosis on spinal deformities, trunk asymmetry, and frontal lower rib cage in adolescent idiopathic scoliosis

STUDY DESIGN: Prospective study. OBJECTIVES: To document immediate and late changes in shape and balance of the thoracic and lumbar spine and lower rib cage on the frontal plane induced by treatment with a thoracolumbosacral orthosis (TLSO). SUMMARY OF BACKGROUND DATA: The effect of TLSO on lateral plane of spinal deformity, frontal lower rib cage, trunk balance, and natural history are poorly understood. METHODS: Twenty-four female adolescents with major thoracic and/or lumbar scoliosis, averaging 30 degrees and 26 degrees, respectively, were treated with a full-time TLSO program. Scoliosis, kyphosis, convex, and concave rib-vertebral angles T7 to T12, frontal trunk balance, frontal vertebral inclination, rotation and translation from T7 to L4-vertebrae were measured before bracing, 1 month after bracing, and biannually thereafter in brace and without brace for a 4-year period and reevaluated at the age of 20 years, at an average of 3.5 years after termination of bracing to measure any permanent changes. RESULTS: Thoracolumbosacral orthosis treatment corrected both thoracic and lumbar scoliosis and reduced lateral trunk shift at the expense of significant, although temporary reduced physiological thoracic kyphosis, increased lateral displacement of T7 to T10, increased frontal inclination of L2 to L4, and elevation of the apical concave rib in favor of reduction of lateral displacement of T11 to L4; decreased frontal inclination of T7, T9, and T11; and derotated L1 and L2 and thoracic apical vertebra without affecting drooping of the 7th to 12th ribs. In this series, there was marked inconsistency in the obtained changes in several of the roentgenographic parameters in the different evaluations, which is probably because of the empiric application of the TLSO during different periods of treatment. 3.5 years after termination of TLSO-wearing, all roentgenographic parameters remained to the prebrace values. CONCLUSIONS: Thoracolumbosacral orthosis program maintained the measured roentgenographic parameters at the prebrace levels in progressive adolescent idiopathic scoliosis, but it had no effect on the droop of the seven lower ribs. The TLSO treatment stopped progression of scoliosis and reduced the number of patients requiring surgery. Thus, it changed the natural history of scoliosis.