|
|
2022, Vol. 26 ›› Issue (9): 1323-1328Relationship between revascularization and internal microstructure changes in osteonecrosis of the femoral headLi Huo1, Wang Peng1, Gao Jianming2, Jiang Haoran2, Lu Xiaobo1, Peng Jiang2
Abstract: BACKGROUND: One of the pathological features of osteonecrosis of the femoral head is damage to the blood circulation of the femoral head, which leads to osteonecrosis and microfracture of the femoral head. The exact pathophysiological mechanism is not completely clear, but it is generally believed that it is closely related to interruption of the intraosseous circulation and death of the bone tissue. Osteonecrosis of the femoral head mainly includes ischemia and the subsequent repair process. However, few studies have explored the relationship between ischemia and repair in occurrence and development of osteonecrosis of the femoral head. OBJECTIVE: To analyze changes in blood perfusion during the repair of osteonecrosis of the femoral head through dynamic contrast enhanced-MRI and thereby to clarify the changes in blood perfusion and the corresponding internal microstructure during osteonecrosis of the femoral head repair. METHODS: Dynamic contrast enhanced-MRI technique was used to scan each subject. Region of interest was drawn in the necrotic area, repair reaction area and normal area (femoral neck or greater trochanter) of osteonecrosis of the femoral head patients. For each region of interest, we got the corresponding contrast medium concentration, and calculated the semi-quantitative parameters of the corresponding curve (peak intensity, peak time, area under the curve, and initial slope). The “origin” software was used for data processing, the contrast media data of the region of interest of patients with osteonecrosis of the femoral head was obtained, and the statistical results of the contrast medium were compared with the results of optical microscope on the corresponding decalcified sections to explore the changes of the internal structure of osteonecrosis of the femoral head in different stages. RESULTS AND CONCLUSION: (1) The statistical analysis showed that the average concentration of contrast medium in the repair reaction area of osteonecrosis of the femoral head was significantly higher than that in other areas (P < 0.05). (2) The statistical analysis showed that the maximum peak intensity value, area under the curve and initial slope of curve of concentration of contrast medium were significantly higher than those in other areas (P < 0.05). With the progression of the disease and the occurrence of collapse, this gap was more obvious. (3) Histological analysis showed that the bone trabecular structure in the reparative reaction area was continuous before collapse. With the occurrence of collapse, trabecular absorption increased, surrounded by a large amount of fibrous granulation tissue and neovascularization. (4) The results showed that the blood perfusion in the repair reaction area of osteonecrosis of the femoral head is significantly higher than that in other areas, and the increase in blood perfusion in the repair reaction area becomes more obvious with the occurrence of collapse. The increase in blood perfusion in the repair reaction area accelerates trabecular absorption in this area, which is closely related to the occurrence of osteonecrosis and collapse of the femoral head. Key words:osteonecrosis of the femoral head, dynamic contrast enhanced MRI, trabecular microstructure, pathology, reparative reaction, neovascularization |