On the pathogenesis of spondylosis deformans and arthrosis uncovertebralis: comparative form-analytical radiological and statistical studies on lumbar and cervical vertebral bodies.

To investigate the etiopathogenesis of the common clinical symptoms of the lower lumbar spine (LS) and cervical spine (CS) (lower back pain and local cervical spine syndrome), the dimensions of the third to fifth lumbar vertebral bodies (LVB) and the fifth to seventh cervical vertebral bodies (CVB) were studied quantitatively and morphometrically in frontal and sagittal planes, as a function of sex and age, in 105 human cadavers of both sexes aged between 16 and 91 years. The evaluation was done in X-ray pictures of 100-micron-thick polished bone sections with the aid of the Macro Facility of the Leitz Texture Analysis System. In each case, the maximum and minimum heights and widths and depths and the computed differences in heights, widths, and depths were determined. The results were evaluated statistically and compared within and between the two regions of the spine, using regression-correlation analyses. The heights, widths, and depths of the VB are all greater in men than in women; their behavior during ageing is, however, identical for both sexes. The heights of all the VB examined remain constant throughout life after termination of growth. The maximum widths and the width differences reveal an increase in both LVB and CVB in old age. All depth parameters reveal constancy in the case of the LVB but an increase in the case of the CVB in old age. The correlation coefficients of the maximum width of the VB within the spinal regions are very high in the LVB, but lower in the CVB. Between the two regions, in contrast, they are very low. This behavior suggests a superordinate action principle within each of the spinal regions which is based on characteristic anatomical construction and functional stressing. The static stressing of the LVB leads, laterally to disc protrusions. As a result of this, traction forces acting on the weak lateral elements of the anterior longitudinal ligament, stimulate the accretion of spondylotic osteophytes at the point of insertion of the ligament on the vertebral body. Anteriorly, in contrast, the particular strong anterior longitudinal ligament prevents such a remodelling process. Posteriorly, the longitudinal ligament is attached to the intervertebral discs, and can thus not stimulate the vertebral body to produce osteophytes. The dynamic stressing of the CVB leads laterally to friction between the VB in the region of the uncovertebral joints and to the formation of arthrotic osteophytes. Anteriorly, owing to the weak configuration of the anterior longitudinal ligament in this aspect, disc protrusion occur and, subsequently, spondylotic osteophytes accrete.