Correlative Study Of OA Bone Cartilage Unit In Rabbits

PART ONE THE ROLE OF THE THREE-DIMENSIONAL STRUCTURE OF THE BONE AND CARTILAGE UNIT IN THE PROCESS OF RABBIT OAObjective: this experiment through the study of rabbit knee joint instability model of cartilage and subchondral bone gross and microscopic structure changes observed in different period don’t OA bone cartilage complex in articular cartilage and subchondral bone between the interaction mechanism, to explore the effect of subchondral bone and cartilage in OA pathogenesis of.Methods: 40 New Zealand white rabbits were selected and randomly divided into 4 groups: A, B, C, D,, and the two groups were randomly divided into two groups. With 10 rats in each group, using ACL cut method to make a rabbit model of OA, after modeling 4, 6, 8, 12 weeks followed the line of the depth were euthanized animals in 4 groups, 10 rats in each time point, with a scalpel will bilateral knee disarticulation, gross observation of the characteristics of the four groups of rabbits knee joints, with a trephine in knee weight-bearing area and the corresponding region from bone- cartilage complex, respectively, Mirco-CT scan and he staining and safranin O / solid green staining and Mankin score and collagen Immune Histochemistry and finally used statistical methods to analysis structure, draws the conclusion.Results: Histological staining results: normal cartilage, cartilage surface is smooth and no crack; OAI period visible surface layer of cartilage fibrosis; OAII cartilage wear thin, vascular ingrowth of calcified cartilage layer; oaiii bone under the cartilage fracture depth of cartilage, subchondral bone plate significantly increased thick; OAIV full-thickness cartilage defect, subchondral bone exposed. Mirco-CT scan results normal bone- cartilage complex to OAI-IV period, the bone volume fraction, bone mineral density, trabecular number and tissue mineral density, trabecular bone thickness showed a growth trend, bone trabecular spacing and structure model index showed a downward trend and between groups have statistically significant difference(P < 0.05). Makin score was significantly positively correlated with BMD, BVF, and Tb.Th(P<0.001), and was negatively correlated with SMI(P<0.001). Immunohistochemistry results showed that: with OA stage deepen, the synthesis of type II collagen in the cartilage is gradually reduced and to the underlying distribution trend; subchondral bone in type X collagen synthesis is increased and directed the trend of distribution;Conclusion: the three dimensional structural remodeling and cartilage degeneration of the cartilage are mutually supportive, and they are a functional complex in the process of OA. THE SECOND PART STUDY ONBIOMECHANICAL PROPERTIES OF RABBIT OA BONE- CARTILAGE UNITObjective:: To observe the effects of the experiment through the study of rabbit knee joint instability model of cartilage and subchondral bone biomechanical characteristics in different period don’t OA bone cartilage complex in articular cartilage and subchondral bone mechanical properties interaction mechanism in the pathogenesis of OA’s role.Methods: using the method obtained bone cartilage complex samples, the samples were divided into 5 groups, normal group and OA I, II, III and IV were respectively, cartilage of the axial compression test, a gradual reduction in a stress relaxation experiment, creep experiment and the subchondral bone compression mechanical test. Finally, using the statistical method analysis results, draw the conclusion.Results: the mechanical test results show: OAI, phase II of cartilage homeostasis compression modulus, stress relaxation and creep time and are smaller than that in the normal control group, the cartilage, but a paired t test had no significant difference(P < 0.001). The balance of oaiii cartilage compression modulus, stress relaxation time, creep time and normal cartilage group have significant difference, OAI, OAII and oaiii period were compared. There was a significant difference between; phase III OA cartilage elastic modulus lowest stage IV OA cartilage bone elastic modulus, hardness is the highest in the.Conclusion: excessive mechanical stimulation can lead to a decrease in the elastic modulus of cartilage, resulting in subchondral bone elastic modulus increases, the interaction between the two, the mutual support of the bone cartilage complex, eventually lead to the occurrence of osteoarthritis. PART THREE DETECTION OF PROTEIN AND GENE LEVELS OF RABBIT OA BONE- CARTILAGE UNITObjective: this experiment through the study of rabbit knee joint instability model of cartilage and subchondral bone gene and protein level of expression observed in different period don’t OA bone cartilage complex in articular cartilage and subchondral feature genes in bone expression and content in the, to elaborate the OA in gene level of.Methods: experimental method is used to get bone cartilage complex samples, separation of the articular cartilage and subchondral bone, respectively by PCR method and Western blot method was used to detect the COL10A1, aggrecan, ctsk, Runx2, BMP-2, OPG and IGF-1 and rank gene and protein expression, finally used statistical methods to analysis results, draws the conclusion.Results: the experimental results showed that: the cartilage part: cartilage matrix differentiation related genes COL10A1 increased, IV reached the highest, Aggrecan showed a downward trend, the highest expression of the normal group. Cartilage damage related genes IGF-1, MMP-13 showed an upward trend, and OA expression was highest in IV phase. Compared with the normal group, the two groups of III OA phase and IV phase had significant difference(P < 0.05). Angiogenesis related genes of VEGF-2 in stage III expression highest between groups differences were statistically compared; part of the subchondral bone to bone related gene expression of BMP-2 in stage III OA expression highest oaiii stage, stage IV two group and normal group compared with significant difference(P < 0.05). The expression of osteoclast related gene OA was highest in the II phase of RANK, and there were significant differences between the groups(P < 0.05). Westemblot results showed that the-13 MMP and other genes related to the final differentiation of cartilage cells increased, and reached the highest in the IV phase. The expression of osteogenic activity related genes OPG and OA in the III phase Runx2 was highest, and there were significant differences between the groups(P < 0.05). The expression of osteoclast activity related gene RANK was highest in II phase OA, and there were significant differences between the groups(P < 0.05).Conclusion: early high expression of cartilage associated gene Aggrecan in osteoarthritis, high expression of VEGF- 2, high expression of MMP-13 in the late stage. In the early stage of the bone, the early osteoclasts were active, and the later stage was the main activity;...