Dorsal instrumentation for idiopathic adolescent thoracic scoliosis: rod rotation versus translation

The radiographic and clinical outcomes and complications among two groups o f adolescent patients treated for idiopathic thoracic scoliosis with dorsal instrumentation using a unified implantation system (Universal Spinal Syst em) were compared retrospectively. A total of 69 patients were included in the study. In 30 patients an intraoperative correction of the scoliosis was performed by translation and segmental correction (translation group, Hels inki). In 39 patients the correction was achieved according to the Cotrel-D ubousset rod rotation maneuver (rod rotation group, Berlin). The goal of th e present study is to investigate whether one of the operative procedures l eads to a better correction of idiopathic adolescent thoracic scoliosis tha n the other. The mean follow-up interval was 30 months, with a minimum of 1 2 months. There were no significant preoperative differences in age (15 +/- 2 years in both groups). gender, or type of scoliosis (King types 2, 3, an d 4). The preoperative radiographic measmements showed no significant diffe rences between the two groups. In both patient groups, the thoracic primary curve, the lumbar secondary curve and the thoracic apical rotation were im proved by the operation. Lumbar apical rotation and the sagittal profile we re unchanged in both groups. he thoracic primary curve was corrected from 5 0 degrees +/- 6 degrees to 24 degrees +/- 7 degrees in the translation grou p and from 54 degrees +/- 11 degrees to 22 degrees +/- 11 degrees in the ro d rotation group. The extent of the correction of the thoracic curve was si gnificantly greater in the rod rotation group than in the translation group (59% vs 52% correction). In contrast, the translation procedure seems to h ave a more beneficial effect on spinal balance than rod rotation. Neurologi cal complications did not occur. In both patient groups an increase in the non-instrumented lumbar curve was noted, in two cases each. In three patien ts from the rod rotation group the instrumentation had to be removed due to a late infection with negative microbiological results.