| Objective:To explore the establishment of the beagle dogs femoral-head osteonecrosis animal models by liquid nitrogen freezinat. The efficacy of model is detected by the histological and immunological examination. Then these animal models are used into exploring a new way of treatment femoral-head osteonecrosis by a new titanium alloy type of femoral head interior surpporting system. The efficacy of new treatment will be evaluated by comparing with core decompression and bone grafting implantation group.Methods:Unilateral early-stage osteonecrosis was induced in nineteen healthy adult beagle dogs using liquid nitrogen freezing. At eight weeks after carrying out the liquid nitrogen freezing, four beagle dogs were randomly choosed to perform the histological and immunological examination of nomal-lateral and model-lateral to evaluate the efficacy of model. The rest fifteen begale dogs were randomly divided into3groups: control group (group A, five), core decompression and bone grafting implantation group (group B), a new titanium alloy type of femoral head interior surpporting system and bone grafting implantation (group C, five). The health side of three groups is treated as self-control. The histological and immunological examinations are made at3months after the treatment. T test will be used to compare of femoral-head osteonecrosis and repairement between nomal-lateral and model-lateral(or treatment-lateral). One-Way ANOVE will be used to compare of femoral-head osteonecrosis and repairement in A、B and C groups. LSD will be choosed to post hoc multiple comparision for observed means. The P<0.05means a significant difference.Results:1The result of liquid nitrogen freezinat. At eight weeks after carrying out the liquid nitrogen freezing, limp of model-lateral became more serious, and there was no dog died. General observation showed that appearance of model-lateral of the femoral head was irregular, mild cystic changes and local bone seleros was in the subchondral area of the femoral head, the color of subchondral tissue became dim and some yellow spots could be abservated in some articular cartilage. The histological examination showed trabecular bone became rarefaction, thinning, fractured. Diffuse presence of empty lacunae was seen. Intramedullary hematopoietic cells significantly reduced, showing tiny intravascular thrombosis. The percentage of trabecular bone area fraction of model-lateral and nomal-lateral were respectively (37.18±1.20)%and (40.77±0.90)%, with a significant difference (P<0.05). The percentage of empty lacunae of model-lateral and nomal-lateral are respectively (20.54±0.66)%and (11.71±0.59)%, with a significant difference(P<0.05).The gray scale of Bax of model-lateral and nomal-lateral are respectively (95.48±3.01) and (114.06±3.43), with a significant difference (P<0.05).2The result of three treatments. The histological examination showed that in group A, trabecular bone became rarefaction, thinning, fractured. Diffuse presence of empty lacunae was seen. Intramedullary hematopoietic cells significantly reduced, showing tiny intravascular thrombosis. In group B, trabecular bone arrayed regularly, few empty lacunae could be seen. Intramedullary hematopoietic cells was rich and the number of nomal osteocyte was large. Pyknosis, karyolysis, and karyorrhexis were not obviously observed. The appearance of C was the same with B. The percentage of trabecular bone area fraction and the empty lacunae area fraction in group A was significantly different from group B and C (P<0.05), also with significant difference comparing the nomal-lateral (P<0.05). Group B and C with no significant difference from each other (P>0.05), and were no significant difference comparing the nomal-lateral (P>0.05). The immunological examination showed that the gray scale of Bax in group A was significantly different from group B and C (P<0.05), also with significant difference comparing to the nomal-lateral (P<0.05). Group B and C with no significant difference from each other (P>0.05), and were no significant difference comparing to the nomal-lateral (P>0.05).Conclusions:The experiment of build avascular necrosis of the femoral head in adult beagle dogs by liquid nitrogen freezing is quite successful. The way of using a new titanium alloy type of femoral head interior surpporting system implantation to treat avascular necrosis of the femoral head can effectively restore and maintain the biomechanical properties of femoral head, promote the repairment of necrotic area, angiogenesis, protect bone cells and prevent femoral head collapse, with no difference from core decompression and bone grafting implantation group in short effect. |
PDF Full Text Request