Abstract

INTRODUCTION AND AIM OF THE STUDY: Whereas Harrington instrumentation (HI) has demonstrated satisfactory frontal plane correction, sagittal plane realignment is difficult. Sagittal plane control is reported to be easier with Cotrel-Dubousset instrumentation (CDI). This study was undertaken to determine if in our series sagittal realignment was achieved with CDI in idiopathic curves classified according to King. MATERIAL AND METHODS: Ninety-seven patients with idiopathic scoliosis classified according to King and treated with CDI underwent coronal and sagittal plane analysis by an unbiased observer. The sagittal curves were measured with the Cobb method from T4-T12 (normals: +25 to +40 degrees) and L1-L5 (normals: -40 to -55 degrees). The thoracolumbar junction (TJ) was divided into an upper TJ (T10-T12) and a lower TJ (T12-L2) with normals between 0 and +10 degrees for the former and 0 and -10 degrees for the latter. RESULTS: In all types of scoliosis with associated thoracic hypokyphosis a significant realignment could be achieved, ranging from 8 degrees in King 1 and 3 curves to 19 degrees in King 4 curves. In normokyphotic curves no significant changes of the thoracic spine were measured postoperatively. Concerning the upper TJ, pathological lordosis was corrected by 7 degrees on the average, whereas correction of kyphosis ranged from 8 to 18 degrees Cobb. Pathologic kyphosis and hyperlordosis of the lower TJ showed a mean correction of 7 degrees and 11 degrees, respectively. There was no significant direct influence of CDI on the sagittal plane of the lumbar spine. CONCLUSION: The data from this study suggest that correction in the sagittal plane can be achieved with CDI in King-classified scoliotic deformities.