What is spondylosis?

 When disc protrusion is progressive (as experimental research has shown) in 1.5 −2 months spondylosis is developing. It is also known as traction spur that is a horizontal excrescence of osseous tissue located on the edge of the vertebral body in ventral (Latin “venter” i.e. abdominal) or dorsal segments (Latin “dorsum” i.e. back or spinal) depending on biomechanical burden.

As it is known fibers that constitute a fibrous ring are divided into three groups the most external of which is fastened to the exterior of vertebral bodies in the point located about two millimeters from the edge of vertebral body.When on the stage of segment instability the jointed vertebrae become hypermobile, these external fibers of the fibrous ring undergo the most significant and strong tension.In the point of their attachment the overirritation of tissues cause the traction spur- – strictly horizontal excrescence of osseous tissue in the point located 2mm from the edge of vertebral body.The form is stipulated by the anatomic structure of the fibrous ring of intervertebral disc and the stage of degeneration of intervertebral disc.

 Thus, spondylosis is an adaptive change of osseous tissue directed to the stabilization of increased movement amplitude in the vertebral and locomotive segment. It increases the total space of vertebral body and that diminishes the total load on the intervertebral disc. Simply speaking in case with protrusion the total space of intervertebral disc is increasing and the space of vertebral body is also increasing so that to reach stabilization due to osteophyte. Osteophyte is the so–called spondylosis.

 Spondylosis is a an adaptive change of osseous tissue directed to the stabilization of increased movement amplitude in the vertebral and locomotive segment.

It’s necessary to distinguish spondylosis from osteophytosis. As it is known, fibers that constitutes a fibrous ring are divided into three groups, the most external of which is fastened to the exterior of vertebral bodies in the point located about two millimeters from the edge of vertebral body. When on the stage of segment instability the jointed vertebrae become hypermobile, these external fibers of the fibrous ring undergo the most significant and strong tension.

In the point of their attachment the overirritation of tissues cause the traction spur – strictly horizontal excrescence of osseous tissue in the point located 2mm from the edge of vertebral body. The form is stipulated by the anatomic structure of the fibrous ring of intervertebral disc and the stage of degeneration of intervertebral disc. Thus, spondylosis is an adaptive change of osseous tissue directed to the stabilization of increased movement amplitude in the vertebral and locomotive segment. It increases the total space of vertebral body and that diminishes the total load on the intervertebral disc. Yumashev G.S. and Furman M.Y. described spondylosis as a process with primarily affected external fibers of fibrous ring and preserved elasticity of the pulpal nucleus.

          Osteophytes appear as a result of calcification of anterior or posterior longitudinal ligaments. At this form of pathology the author discovered on the posterior surface of vertebral bodies in periosteum the cambial layer with cells able to become active due to the tension of posterior longitudinal ligament, given the protrusion of intervertebral disc. In mechanism of development of ossification of longitudinal ligaments the main role is played by the mechanical impact of the protruding fibrous ring. There are monosegmental, polysegmental and combined ossification of posterior longitudinal ligament. Depending on the location of ligaments in the point of attachment to the vertebral bodies osteophytes have longitudinal, slanting and horizontal direction, but mainly they have irregular slanting shape. Their multiple manifestation is called osteophytosis.

         Thus, osteophytosis has an irregular shape and consists of ossificated ligament, while spondylosis is a true reaction of the osseous tissue to the irritation of periosteum, and it consists of the osseous structure.

The osseous excrescence and the height of intervertebral space points out indirectly to the processes which take place in the intervertebral disc, and that is proved by comparing X-ray and MRI results.

The presence of a small in size traction spur and inconsiderable decrease of intervertebral space proves that degenerative and dystrophic changes in intervertebral disc take place in the stage of intervertebral protrusion. .

A considerable in size spondylosis coupled with decrease of intervertebral space means that there was a segmentary instability at this level in past which was stabilized by the developped stage of fibrotization and vascularization of the affected disc with minimal activity of chondrocytes.

Thus: 1) a presence of spondylosis and osteophytosis increases the reliability of compensation of static disorders from vertebral segments but contributes to biomechanical disorders from other segments of spinal cord;
2) signs of spondylosis development show mainly the speed but not the level of development of degenerative and dystrophic changes in intervertebral disc.