At the Orthopaedic University Hospital of Mainz more than 150 patients were treated surgically according to Cotrel and Dubousset procedure. By means of this operation average corrections of the curves of 54,8% to 64,6% could be achieved in the first 150 patients, depending of the localization of the curve. Operative procedure, duration of operation and blood loss are adequate to known procedures, the stability of the method is better than in other known methods. The change of the postoperative sagittal profile demonstrates the influence of the operation in cases of hypokyphosis in the thoracic and hypolordosis in the lumbar spine.