Densitometric correlates of degenerative-dystrophic processes in cervical vertebrae of humans and domestic animals

Abstract

The cervical spine is the most mobile region with high work activity which constantly receives a heavy load. This region is the least protected from external influences, especially in cases of degenerative-dystrophic changes. A comparative analysis of clinical-morphological and morphometric data in degenerative-dystrophic lesions of the cervical spine in humans and domestic animals with secondary anatomical and physiological abnormalities was performed . The examined contingent of people was of young and middle age (average age equal to 41.5 ± 5.2 years). The examined animals had a similar age range recalculated to human age. The pathological changes in spinal cord configuration were registered in 84.6% of examined humans (n = 65) in the form of angular kyphosis or straightened lordosis (with the analogous relative distribution). In terms of gender, with the exception of the frequency of angular kyphosis, probable differences in the formation of lordosis, which is straightened (2.1 times more often), the indicators were the same while the normal configuration of the spine was more often registered in men against the women (20.0% vs 12.5%). Cervical spine deformations in different breeds of dogs and cats (n = 75) were observed in 34.7% of cases (angular kyphosis – 38.5%; straightened lordosis – 61.5%). Preservation of normal configuration of the cervical spine was recorded more often in cats – 78.6%, and in small breeds of dogs – 78.5%. In large breeds of dogs, these indicators were probably changed: the norm remained only in 26.3%, and the deformations exceeded the corresponding indicators in cats and small breeds of dogs by 2.7 or more times. The significant differences were found in cases of straightened lordosis formation which was registered more often in women than in men. The incidence of angular kyphosis was comparable in patients of both sexes. Cervical spine deformations in different breeds of dogs and cats were observed in 26 animals (34.6% cases: angular kyphosis – 13.3%; straightened lordosis – 21.3%). The densitry of vertebral bodies in all groups decreased in the caudal direction of the cervical spine. The differences in humans reached 18.1%, being higher in women than in men. Animals had a similar density distribution. This index was minimal in cats (2.7%), in small-breed dogs it increased significantly (7.5%) and in large-breed dogs it reached 14.3%, i.e. 5 times (compared to cats) and 2 times higher (compared to small breed dogs). A comparative analysis between humans and animals indicates that the maximal discrepancies in the studied indexes were found in humans and relatively coincided with those in large breed dogs. The presence of neurological deficit with cervical spine pain syndrome with lordosis distortion and the provocation of spinal canal stenosis was found in 73.7% of large adult dogs. The revealed regularities of cervical spine degenerative-dystrophic changes indicate that animals, especially large breeds of dogs, can serve as a model for investigation of etiopathogenetic factors, clinical course, prognosis and other risks of the bone-cartilage apparatus degeneration with both stenosis and vertebrogenic myelopathy development at the cervical level in humans The obtained clinical and morphometric data from comparative analysis in humans and domestic animals will serve as the basis of methods of prevention of degeneration in the bone-cartilage apparatus and the premature aging of the body in humans.