EARLY DETECTION OF PROGRESSION IN ADOLESCENT IDIOPATHIC SCOLIOSIS BY MEASUREMENT OF CHANGES IN BACK SHAPE WITH THE INTEGRATED SHAPE IMAGING-SYSTEM SCANNER

Study Design. A retrospective study of 78 patients with right thoracic idiopathic scoliosis was done. Objectives. To evaluate the reliabilit y of the Integrated Shape Imaging System scan (Oxford Metrics Ltd, Oxf ord, UK) in detecting progression of scoliosis and the use of back sha pe data in predicting scoliosis progression. Summary of Background Dat a. At first presentation and every 3-6 months during the follow-up per iod, all patients underwent Integrated Shape Imaging System scans and radiographic examinations, from which the Cobb angle was measured. The follow-up period was 18-49 months (mean = 31.4 months). Methods. Pati ents were divided into three groups according to the severity and prog ression of the Cobb angle. The spinal fusion, brace, and observation g roups Were compared using analysis of variance and the student's t tes t to detect significant differences among groups in the progression of deformity as measured by the integrated Shape Imaging System paramete rs and the Cobb angle. Results. Three of the Integrated Shape Imaging System parameters detected significant progression in the spinal fusio n group 1 year earlier than the Cobb angle. Only one of the Integrated Shape Imaging System parameters detected a significant difference in progression between the brace and observation groups. Conclusions, The Integrated Shape Imaging System technique demonstrated significant ch anges ip this group of patients with progressive scoliosis. Serial mea surements of back surface shape, particularly the size of the rib hump , may be predictive of progression. Serial Integrated Shape Imaging Sy stem scanning has advantages over serial radiography in the management of idiopathic scoliosis in addition to the avoidance of exposure to i onizing radiation.