Comparative chemical composition analysis of femoral condyles bone tissue in health and in deforming arthrosis
A comparative analysis of the chemical composition of the medial and lateral condyles of the femur in norm and with deforming arthrosis of the third degree is presented. It was found that when the bone tissue of the femur is degraded from the surface, a decrease in crystallinity is observed in depth, quantitative and qualitative changes in the organic bone matrix, in particular, a decrease in the proportion of the protein component, a change in the phase inorganic composition, and an increased degree of substitution of calcium in hydroxyapatite for ions of other metals. And the most dramatic changes are observed in bone tissue located near the pathologically deformed areas. It is shown that the data for normal bone tissue of the lateral and medial condyle of one specimen differ, which can be caused by different degrees of stress on the condyles themselves in the process of vital activity of the organism caused by asymmetry and a different shape of their articular surfaces. With deforming arthrosis in the surface layer of bone tissue, the concentration of calcium and a number of other metals increases, while the proportion of the protein component decreases. It was revealed that in the affected bone replacement of phosphate tetrahedra with carbonate ions occurs, as well as substitution of cations of divalent calcium with ions of other metals such as copper and manganese, and especially ferric cations. This breaks the overall structure of the crystal lattice of hydroxyapatite and affects the biomechanical properties of the surface, in particular, the reduction of trophism and the elasticity of the surface. In osteophyte tests, partial replacement of phosphate groups with carbonate groups occurs. Isomorphic structural substitutions caused by deposition of crystalline impurities lead to a change in the ratio of calcium and phosphorus concentrations. Excessive deposition of calcium salts leads to the formation of osteophytes.