OPERATIVE TREATMENT OF IDIOPATHIC THORACO LUMBAR SCOLIOSIS - COTREL-DUBOUSSET INSTRUMENTATION VERSUS VENTRAL DEROTATION SPONDYLODESIS

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-Du bousset Instrumentation (CDI), 10 patients underwent Ventral Derotatio n Spondylodesis (VDS). In 2 cases a combined two-stage VDS and CDI wer e performed. The follow-up was 38 months in the CDI-group and 19 month s 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 exce eded curve length by 4 segments on average. With CDI the fusion was ca rried down to L4 in most cases, in some cases to L5. Curve correction of the primary curve averaged 70% with VDS (pre-operative mean 84 degr ees) and 64% with CDI (preoperative mean 65 degrees). We observed a sp ontaneous correction of the secondary curve of 38% after VDS. With CDI the correction of the secondary curve averaged 42%, however, in secon dary 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 averag e kyphosis of the thoracolumbar junction of +22 degrees was corrected to +7 degrees. We conclude that in the operative treatment of severe t horacolumbar scoliosis VDS offers significant advantages compared to C DI and should therefore be prefered. In moderate scoliotic deformities , where the number of caudally unfused segments is equal in both syste ms, CDI is justified.