Orthopedics - Oleksa A.P. 2006

Pathophysiology of joints
Developmental defects and congenital skeletal anomalies
Enchondral dysostoses (dysplasia ossium)

Enchondral dysostoses are also referred to as dysplasias, as they encompass a poorly understood group of disorders.

Dysostoses can cause severe Congenital Malformations, leading to dwarfism and disability in some cases, while presenting in milder forms in others.

The causes of dysostoses remain fully undetermined, and the underlying pathology involves impaired endochondral ossification, primarily affecting the epiphyses of long bones, the spine, and their growth plates. In certain types of dysostosis, mucopolysaccharide METABOLISM is disrupted, resulting in urinary excretion levels that exceed normal values, along with The excretion of heparan sulfate, chondroitin, or keratan, depending on the specific type of dysostosis.

Mucopolysaccharides also influence the course of other conditions (such as Morquio, Hunter-Hurler, and Sanfilippo syndromes); however, metabolic abnormalities in these disorders are not consistently present, and the underlying cause of altered enzyme activity sometimes remains unknown.

In many cases of dysostosis, laboratory investigations reveal no significant deviations from baseline parameters, with serum calcium, phosphorus, alkaline phosphatase, and protein levels remaining within normal limits.

Cartilage examinations reveal pathological changes that are similar across various clinical manifestations of dysostoses. These alterations are not pathognomonic, and their severity varies considerably.

Certain dysostoses are genetically inherited. Gene Mutations can disrupt normal endochondral ossification. Dysostoses are classified as rare conditions affecting both sexes equally.

The disease may manifest prenatally (chondrodystrophy) or in infancy (nanismus diastrophicus), though in most cases it becomes apparent when children begin to walk or shortly thereafter. In adulthood, secondary degenerative changes develop as a consequence of undiagnosed and untreated pathology.