[Role of computed tomography in the estimation of the density of the bony block of an injured vertebral column segment at different stages of treatment with an external transpedicular fixation apparatus].

A Somatom AR.HP computed tomograph (Siemens) was used to make studies in 54 patients with injury to the vertebral column and spinal cord in order to determine the formation of a bony block and its density in different portions of an injured segment at the stages of treatment. During therapy, the highest values of bony block density were observed in the dorsal portions of an injured segment (mean 377.32 +/- 184.57 HU). This may be accounted for by a slight effect of artefacts of an external transpedicular fixation apparatus, the main components of which are present at the posterior supporting complex. After treatment, the highest values of bony block density were noted in the central portions of an injured segment (mean 353.11 +/- 208.01 HU). This may be associated with rather serious intervertebral disk damage in this portion. The bony block density index was 339.75 +/- 139.41 HU in the left lateral portions and as high as 312.56 +/- 135.07 HU in the right ones. In the late period, the highest bony block density index (mean 397 +/- 193.07 HU) was seen in the right portions of an injured segment, which may be due to slight scoliotic deformity with the angle being open to the right.