Abstract
Vertebral rotation in the axialplane is thought to be the primary deformity in the pathogenesis of idiopathic sco-liosis. İn this study 62 patients with idiopathic scoliosis treated by Cotrel-Dubousset Instrumentation at the 1st Or-thopaedics and Traumatology Clinic of Ankara Social Security Hospital from December 1988 to June 1991 were evaluated. Preoperative and postoperative rotation degrees of the apical, intermediate and end-neutral vertebrae of the hpatients were measured by computed tomography. The maximum amount of correction at the apical verte-bra was obtained in King Type III curves in which a derotation manoeuvre had been performed and RAsag, RAml and RAdev angles were corrected by 24.8± 16,9 %, 25,8 ± 18,4 % and26,5± 20,8 % respectively. This group was follovved by King Type IV and Type II curves. Derotational effect was minimal in the lumbar region in King Type I and Type II curves. The highest amount of derotation occurred in the apical vertebrae followed by the intermediate vertebrae and was almost zero at the end vertebrae. İt vvas concluded that the derotational force affected mainly the scoliotic curve and was not carried segmentally to the distal or proximal parts of the vertebral clomn and did not cause decompensation.
Keywords: İdiopathic Scoliosis, Computed Tomography, Cotrel-Dubousset Instrumentation
