| Objective:Through animal experiment，to analyse the pathogenesis of steroid-inducedfemoral head necrosis under the condition of vasculitis. When the animals received steroid,L-Dopa and Alendronate Sodium were applied to intervent the osteonecrosis. Thechanges of BGP, TRACP-5b, BMD and the degree of femoral head necrosis wereobserved to supply effective evidence of femoral head necrosis intervention for clinicalpractice.Methods:50heathy Chinese albino white rabbits (20weeks old) weighting2.5±0.5Kg were randomly divided into5groups. Group A received no medication andserved as the control group．Group B were injected LPS (10ug/Kg) via ear vein,3consecutive MPS sodium succinate injections (20mg/Kg) via right buttock were thencarried out24h later with24h interval. Without pharmacological intervention. Group Cwere treated by the same method as to the rabbits in the group B, then oral intake oflevodopa (0.4g/Kg/day) at the same day of the last injection of MPS sodium succinate wascarried out. Group D were treated by the same way as to the rabbits in the group B, thenoral intake of alendronate sodium （10mg/day） at the same day of the last injection ofMPS sodium succinate was carried out. Group E the animals of this group were treated bythe same way as to the rabbits in the group B, then oral intake of both levodopa(0.4g/Kg/day) and alendronate sodium（10mg/day） at the same day of the last injection ofMPS sodium succinate was carried out. During the experiment, every group rabbits werefed with standard fodder, all animals were injected with peniciliniun (800,000U/rabbit)twice a week for infection prophylaxis. Blood samples about2ml were taken from every five group rabbits，ear veins6weeks and10weeks. The blood samples were allcentrifugated, and the serums above were collected carefully. ELISA reagent was used forlevels of BGP and TRACP-5b detection in the serum of every rabbit; Bilateral proximalfemurs of every rabbit were performed bone mineral density (BMD)(including the femoralhead) by Micro-CT. Radiographic and MRI of both hip joints were taken in5rabbits fromevery group6weeks and10weeks later respectively, then the rabbits were killed byaeroembolism. Both femoral head samples were taken out, first of all for scanning throughMicro-CT, calculated and analyzed both bone mineral density and bone trabeculaestructure parameters, then immersed in10%formalin, the samples were decalcified,embedded, sliced, for HE as well as apoptosis staining and observed microscopically toobserve ultrastructure change of trabecular bone, bone marrow cells and fat cells. All datafrom experiment were dealed with SPSS17.0statistical package. The data was presentedas (X±s), The statistical analysis was carried out with completely randomized designvariance method, and LSD pairwise comparison test was performed between groups to testsignificant difference.Results:1. Serologic index observation:(1) The comparisons of BGP in group atdifferent time showed: there was no significant difference (P>0.05) between6thand10thweeks in group A. The level of BGP of guoup B and group D at10thweek were higherthan that at6thweek, but had no significant difference (P>0.05). The level of BGP ofguoup C and group E at10thweek increased significantly higher than that at6thweek(P<0.05). The comparisons of BGP between groups of different time showed: group B andgroup D were higher than group A at6thand10thweeks but had no significant difference(P>0.05), group C and group E were significantly higher than group A, groupB and groupDat6thand10thweeks (P<0.01). There was no significant difference (P>0.05) betweengroup B and group D, There was also no significant difference (P>0.05) between group Cand group E.(2) The comparisons of TRACP-5b in group at different time showed: therewas no significant difference(P>0.05)between6thand10thweeks in group A. The level ofTRACP-5b of guoup B and group C at10thweek increased significantly higher than that at 6thweek (P<0.05). The level of TRACP-5b of guoup D and group E at10thweek decreasedlower than that at6thweek, but had no significant difference (P>0.05). The comparisons ofTRACP-5b between groups at different time showed: group B and group C weresignificantly higher than group A at6thand10thweeks (P<0.01), group D and group Ewere lower than group A (P<0.05) and significantly lower than group B and group C(P<0.01) at6thand10thweeks. There was no significant difference (P>0.05) between groupB and group C, There was also no significant difference(P>0.05)between group D andgroup E.2. Imaging observation: The imaging examination including X-ray, MRI andMicro-CT showed:12hip joints of8rabbits in group B,3hip joints of2rabitts in group Cand2hip joints of1rabbits in group D exsited avascular necrosis of femoral head duringthe period of experiment, while group A and group E did not exist the performence ofavascular necrosis of femoral head. The comparisons of BMD between groups at the10thweek: group B was significantly lower than group A(P<0.01); Group C and group D waslower than group A (P<0.05); Group E was lower than group A, but there was nosignificant difference(P>0.05); Group C, group D and group E were significiantly higherthan groupB(P<0.01); Group E was higher than group C and group D and there was asignificant difference(P<0.05). There was no significant difference(P>0.05)between groupC and group D. The bone trabecula of group B was significant decreased in Tb.N andTb.Th, and increased in Tb.Sp. Most of the bone trabeculae was fracture and the continuitywas seriously damaged. Group C and group D were better than Group B, while group Ewas the best of all just like the normal group.3. Histopathological observation: Group A: The bone trabecula were regularity,thicked and compact. Many osteoblasts were observed around the trabecula. There weremany bone cells and myeloid element among the trabecula, and the bone nuclei were bigand clear, few empty lacuna could be seen. Fat cells are normal.GroupB: The bone trabecula were messy, thinned and sparse, most of which wereatrophy and fracture. The normal bone cells decreased and more condensation nuclei could be seen. Many empty osteocyte lacunaes were observed but the osteoblasts were rare tobeen seen. Lots of fat accumulated between the bone trabecula, the number of fat cellsincreased and integrted.GroupC: The bone trabecula were slightly regularity,part of them were atrophy andfracture. There were many bone cells with big nuclei in the center. A few of empty lacunacould be seen. Few of fat cells increased and integrted.GroupD: The bone trabecula were regularity and thicked, the continuity was good.Few of osteoblasts and myeloid element were observed around the trabecula. A few ofempty lacuna could be seen. Fat cells were basic normal, few of them integrted.GroupE: The bone trabecula were regularity, thicked and compact. There were manybone cells in the osteocytes. The bone nuclei were big and in the center of bone cells.Many osteoblasts and myeloid element were observed among the trabecula, few emptylacuna could be seen. Fat cells are nearly normal and there was no integrted.Conclusion：(1)Under the condition of vasculitis the application of the high-dosesteroid drug in short-term would induce osteonecrosis of femoral head successfully.（2）As a new testing method, Micro-CT can quckily get the femoral head imageunder the condition of the complete femoral head sample image, calculated and analyzedboth bone mineral density and the system of bone trabeculae space structure, with itsadvantages such as fast detection, high resolution, high accuracy and being on the3dreconstruction analysis.（3）Combine with Levodopa and Alendronate Sodium could reduce the absorbing ofosteonecrosis and osteoporosis, accelerate bone formation and repairment in the meantime.Useing both of them can improve bone destiny and slow down even restrain thedevelopment of necrosis of femoral head effectively. They play a better effectiveness thanthe two drugs used alone on the treatment of the necrosis of femoral head. |
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