[Long-range outcome in idiopathic scoliosis correction with Cotrel-Dubousset instrumentation].

Background. The purpose of this study is to evaluate outcome in idiopathic scoliosis treated surgically with Cotrel-Dubousset instrumentation. Material and methods. We analyzed the results of surgical treatment of 147 patients with idiopathic scoliosis classified according to King. The mean age of the patients at surgery was 15 years (range 12-25 years), and the mean follow-up was 6.3 years (range 3-12 years). Full-length standing preoperative, postoperative and last follow-up radiographs were studied. Radiographic analysis included the Cobb angle, Risser stage, apical vertebral rotation according to Perdriolle, radiological compensation, T2-T12 kyphosis and L1-S1 lordosis. Results. The greatest scoliosis correction was found in the frontal plane (60% in King IV), much lower in the sagittal. The mean loss of correction was 6.5% thoracic and 10.4% lumbar. In lordoscoliosis, postoperative kyphosis was below the normal range. Apical vertebral derotation ranged from 1 to 5 degrees. Derotation in the thoracic curve correlated with increased rotation in the lumbar curve. Decompensation to the left occurred postoperatively in the majority of patients. At last follow-up, the number of decompensated patients and mean decompensation was smaller. No back pain was found in the majority of patients (78.5%), and they judged the final result of treatment to be excellent (77.5%) or good (20.4%). Complications occurred in 10 patients (6.8%), early infection in 2 cases and late in 3. Conclusions. The greatest correction of scoliosis was found in the frontal plane, less in the sagittal. Small correction of the apical vertebral rotation of the main curve correlated with increased rotation in the secondary curve. The final follow-up decompensation was less than postoperatively.