Phenotypic Features of Articular Cartilage Cells in the Femoral Head in Congenital Hip Dislocation

Congenital hip dislocation is a manifestation of a severe degree of hip joint dysplasia, a disabling orthopedic pathology with unclear pathogenetic mechanisms and etiological factors. In congenital hip dislocation, dysplastic processes are identified in the cartilage tissue of the articular surface of the femoral head. Studying the phenotypic characteristics of the articular cartilage cells in the femoral head will help to understand the etiopathogenetic mechanisms of this pathology. The study aims to characterize the cell phenotypes in the femoral head articular cartilage associated with congenital hip dislocation. Material and methods . An immunohistochemical analysis was performed on a culture of articular hyaline cartilage cells from the femoral head obtained from 5 patients with congenital hip dislocation. Five cell culture passages were carried out. Statistical processing of the quantitative data was performed using Microsoft Excel software. Results . During culturing, two cell types of different phenotypes were obtained. Based on a positive immunocytochemical reaction with a key marker of chondrogenic differentiation (anti-type II collagen), the first cell type was identified as chondrocytes and chondroblasts. These are round and polygonal cells that form a monolayer. The second type consisted of process-bearing bipolar and multipolar cells, located in isolation, which exhibited a positive immunocytochemical reaction for the early neural markers PAX6, SOX1, SOX2, Musashi1, and the late neural marker NF200. These cells were defined as being of neural origin. Conclusion . The obtained data will help to assess the involvement of neural-origin cells in the etiopathogenetic mechanisms of congenital hip dislocation development. The interrelationship of the processes occurring during embryogenesis, such as altered migration of neural crest cells, their ectopic localization, and the development of hip joint dysplasia (congenital hip dislocation) requires further investigation.