Quantitation of three-dimensional deformity of idiopathic scoliosis.

Three-dimensional deformities in vertebrae of patients with idiopathic scoliosis were analyzed quantitatively using three-dimensional computed tomography. To evaluate the deformities, the vertebral lordosis and scoliosis were defined clearly. An average lordosis of 7.9 degrees and an average scoliosis of 6.8 degrees were calculated in 40 vertebrae near the top of the thoracic curve in 10 subjects with adolescent idiopathic scoliosis. Lordosis is characteristic of idiopathic scoliosis. Three-dimensional deformities in scoliotic patients cannot be represented precisely using the Cobb angle. A new technique for quantifying the three-dimensional deformities must be established.