The effect of Harrington instrumentation on the longitudinal axis rotation of the apical vertebra and on the spinal and rib-cage deformity in idiopathic scoliosis studied by computer tomography.

The effects of Harrington instrumentation on the longitudinal axis rotation of the vertebra, the kyphosis-lordosis, and the rib-cage deformity were investigated by computer tomography in 33 patients. No significant derotation was achieved. The sagittal diameter of the rib cage was reduced significantly with distraction rod instrumentation and further by additional application of a compression rod. The rib hump was reduced significantly only with distraction rod instrumentation. The obtained results indicate that despite instrumentation, the spine preserves an almost unchanged peripheral position in the rib cage.