In 10 Skoliose-patients undergoing Harringtons-Operation, measurements of the oszillatory impedance and arterial blood gases were made intraoperatively. The resistance was elevated from the beginning without any change during the operation. The phase was in the inductive range with a further deviation during increasing extension. The possible reasons are the maximal rigidity of thorax and/or parenchyma or change in tracheobronchial "arborisation". Increase in dead space or changes in ventilation-perfusion ratio are suggested by the blood gas measurements. Further investigations will be necessary to determine, if the impedance of the lung is of value in determining the amount of intraoperative extension or postoperative lung function.

To determine a possible involvement of CNS in the etiology of the socalled idiopathic scoliosis, some 115 clinically neurologically and psychically inconspicuous patients suffering from idiopathic scoliosis and some 35 patients with congential scoliosis have been submitted to EEG control. The idiopathic scoliosis group showed a significant percentage of divergence from normal EEG results found in the average normal population. The type and the genesis of the cerebral dysfunction as well as a possible correlation with the etiology of the idiopathic scoliosis are discussed below.

No abstract

Total disc mobility, segmental mobility, both depending upon location of the disc and upon its position within the scoliotic curve as well as the opening angle of the disc in the ap x-ray were measured in the so-called "bending-test" x-rays of the lumbar curve of 40 patients with idiopathic scoliosis. The measurements showed a maximum of mobility in the segments L2/3, L3/4 and L4/5. In no direct dependence an increased mobility of the most proximal motion segment against the next lower one of the lumbar curve was found. No direct relation between lateral flexion and degree of scoliosis was measurable. Mobility towards the convexity increases directly with the opening angle of the disc concerned while mobility towards the concavity decreases; lateral flexion remains constant altogether. The results achieved might become quite relevant in connection with the possible therapeutic progress in the treatment of lumbar scoliosis with enzymatic dissolution of nucleus pulposus.

To investigate the question which growth processes take place in dorsally stiffened vertebral regions, 4 vertebral segments each were dorsally fused in twenty-one pigs, using Harrington's distraction system in 20 cases. X-ray examination and histological measurements conducted with the aid of fluorochromosequential markings showed a more or less pronounced growth of the vertebral bodies and of the fusion mass in all animals. As a rule, the sequence of vertebral bodies overgrows the fusion mass in longitudinal direction, which always results in lordosis of the stiffened region. The longitudinal growth of the vertebral bodies, and even more so of the fusion mass, decreases with increasing postoperative observation time. The fusion mass shows actual internal growth which proceeds partly in diffuse manner in all directions, in the region of the clefts, i.e. as spondyloschisis, in some cases also in the same direction as with enchondral ossification associated with columnar chondrification. The growth of the fused mass does not depend on the formation of a pseudoarthrosis, although it is probably quantitatively promoted by pseudarthroses. The stimulus to longitudinal growth of the fused mass originates from the growing vertebral bodies, with probably varying influence of tensile and compressive forces.