A RADIOLOGICAL EVALUATION OF THE CERVICAL SPINE IN CHILDREN

Reports on the sagittal diameters of the cervical spinal canal are outdated, and there has been no report of ADI (atlas-dens interval) in each age of children. Additionally, there is no Ranawat standard value for children. Thus, we obtained these standard values by X-ray measuring 440 cases of normal children. Spinal alignment is the most important factor for normal posture. Through radiographic observation in the 440 cases, we also investigated abnormal findings in childhood causing cervical malalignment and annual characteristic changes leading to malalignment. The values of the cervical sagittal diameter of children were 0.4-0.5mm larger on average than previous years. This was assumed due to recent skeletal development in Japanese children. New ADI standard values for children were obtained, and the index of atlantoaxial dislocation in each age was then calculated. New Ranawat standard values for children were also obtained at this time. It became clear that there is a positive correlation between Ranawat value and age as well as height, and the formulae to obtain the standard value from height were as follows: Boys: Y=4.8941+0.068468X, Girls : Y=5.4687+0.063426X [Y (cm) : Ranawat value. X (cm) : height] . Sagittal malalignment was found in 21 of the 440 cases. In 18 of the 21 cases, the radiographs taken at the first examination showed abnormal findings which were assumed to be the cause of cervical malalignment. Most of the findings showed abnormalities from the vertebral ring apophysis to the end plate and intervertebral listhesis. These findings indicated that one cause of malalignment in most cases might be mild congenital vertebral dysplasia. The incidence of malalignment was relatively high, 4.1% in 18 of 440 cases. Therefore, we should recognize the importance of cervical management at the growth stage.