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 induc ed by treatment wit a thoracolumbosacral orthosis (TLSO). Summary of Background Data. The effect of TLSO on lateral plane of spinal d eformity, frontal lower rib cage, trunk balance,and natural history are poo rly understood. Methods. Twenty-four female adolescents with major thoracic and/or lumbar s coliosis, averaging 30 degrees and 26 degrees, respectively, were treated w ith a full-time TLSO program. Scoliosis, kyphosis, convex, and concave rib- vertebral angles T-7 to T-12, frontal trunk balance, frontal vertebral incl ination, rotation and translation from T-7 to L-4-vertebrae were measured b efore bracing, 1 month after bracing, and biannually thereafter in brace an d 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 per manent changes. Results. Thoracolumbosacral orthosis treatment corrected both thoracic and lumbar scoliosis and reduced lateral trunk shift at the expense of signific ant, although temporary reduced physiological thoracic kyphosis, increased lateral displacement of T-7 to T-10, increased frontal inclination of L-2 t o L-4, and elevation of the apical concave rib in favor of reduction of lat eral displacement of T-11, to L-4; decreased frontal inclination of T-7, T- 9, and T-11; and derotated L-1 and L-2 and thoracic apical vertebra without affecting drooping of the 7th to 12th ribs. in this series, there was mark ed 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 re mained to the prebrace values. Conclusions. Thoracolumbosacral orthosis program maintained the measured ro entgenographic 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.