Surgical treatment of idiopathic thoracolumbar scoliosis: Contrell-Dubousset instrumentation versus ventral derotation spondylodesis

Abstract

Especially in idiopathic thoracolumbar scoliosis the approach and sort of instrumentation have controversially been discussed over the past years. Since 1986 32 patients with adolescent thoracolumbar scoliosis underwent operative treatment, 20 patients were treated with Cotrel-Dubousset Instrumentation (CDI), 10 patients underwent Ventral Derotation Spondylodesis (VDS). In 2 cases a combined two-stage VDS and CDI were performed. The follow-up was 38 months in the CDI-group and 19 months in the VDS-group. Length of the curve and the fusion were identical in the VDS-group. In the CDI-group, however, length of the fusion exceeded curve length by 4 segments on average. With CDI the fusion was carried down to L4 in most cases, in some cases to L5. Curve correction of the primary curve averaged 70% with VDS (preoperative mean 84 degrees) and 64% with CDI (preoperative mean 65 degrees). We observed a spontaneous correction of the secondary curve of 38% after VDS. With CDI the correction of the secondary curve averaged 42%, however, in secondary curves measuring more than 50 degrees primary and secondary curve were fused. A preoperatively physiological sagittal plane in the CDI-group remained unchanged after operative treatment. With VDS an average kyphosis of the thoracolumbar junction of +22 degrees was corrected to +7 degrees. We conclude that in the operative treatment of severe thoracolumbar scoliosis VDS offers significant advantages compared to CDI and should therefore be preferred. In moderate scoliotic deformities, where the number of caudally unfused segments is equal in both systems, CDI is justified.