Isotope scanning with Tc99m-MDP of the spine and the costosternal junctions of patients with idiopathic scoliosis.

Bone scanning of the thoracolumbar spine and the anterior thorax was performed in 7 girls with recently diagnosed progressive thoracic idiopathic scoliosis. A reference group consisted of a group of 8 patients submitted to bone scanning for other reasons. In all 7 girls composing the scoliosis group the isotope uptake by the vertex vertebra, the 2 vertebrae above and the 2 below was homogeneous, with no areas of abnormally increased uptake. In 5 of these patients where quantitative studies were performed there was no significant difference in uptake between the vertex and the other 4 vertebrae. Nor did the 2 groups differ significantly as regards the left-right difference in uptake by the costosternal junctions. The results of this investigation confirm the observation in a preliminary study that there was no disturbance of spinal growth during the early stage of development of idiopathic thoracic scoliosis. However, the results do not support a tentative conclusion drawn on the basis of the preliminary study--namely, that the development of spinal deformity in idiopathic scoliosis might be ascribed to asymmetric longitudinal rib growth, reflected in asymmetric isotope uptake by the paired costosternal junctions. It is questionable however, whether scintigraphic scanning can provide an accurate procedure for quantitative measurement of skeletal growth of the ribs, especially in scoliotic patients.