(1) Reproduction method The weight of female adult New Zealand rabbits with edentulous jaw deformity is 2.0~2.5kg. After anesthesia with 2.5g/L pentobarbital sodium via ear vein at the dose of 1mg/kg body weight, there is no Under the condition of bacteria, only the bilateral temporomandibular joint (TMJ) was punctured in the supraarticular cavity. The low concentration group was injected with 100U LDH (prepared with 0.9% normal saline) 0.1ml on both sides of the TMJ; Inject 200 units of LDH 0.1ml into the upper cavity of both TMJs. After puncture or injection, the animals were killed by overdose of anesthetic at 24h, 1, 4, 8, 12 weeks, and the temporomandibular joint specimens were taken for observation. The TMJ puncture method can palpate two small nodules in the posterior and lower part of the rabbit’s lateral canthus, namely the infraorbital rim and the posterior pole of the condyle. When performing TMJ puncture, insert a needle between two small nodules with the needle pointing forward, inward, and downward, all parallel to the infraorbital rim. After the needle is inserted about 0.5cm, there may be a feeling of hollowing out and no blood will be drawn back, occasionally There is a little viscous light yellow liquid, that is, synovial fluid, which can be drawn back after the injection of the drug. This indicates that the needle tip is in the TMJ cavity.
(2) Model characteristics The degree of joint disease of the model animals is different in each time period. The degree of disease in the high concentration group is all severe in the lower concentration group. Under the light microscope: no obvious lesions were seen in the early stage (1 to 4 weeks). In the later period (4-12 weeks), the fibrocartilage layer becomes thinner, the structure of fibrocartilage layers is disordered, the articular disc collagen fiber is hyaline degeneration, the synovial thickening cell component increases, the bone in some areas is exposed, and the bone in some areas of the condyle Degeneration, degeneration and breakage of collagen fibers in the articular disc. There were no obvious abnormalities on the surface of the joints in the early stage (1 to 4 weeks) under the scanning electron microscope. In the late stage (4-12 weeks), the gel layer on the upper surface of the articular disc becomes thinner, the reticular collagen fibers are exposed, the gel layer material falls off, the surface of the articular disc becomes shallower or even disappears, and the condyle surface becomes shallower and gelled The layer is peeled off, the reticular collagen fiber filaments are exposed, a large number of collagen fiber bundles are rolled up and exposed, and the corrugated structure disappears in the functional area of the anterior condyle, and the gel layer becomes thinner. A large number of collagen filaments are exposed. The model animals all developed characteristic osteoarthropathy lesions 4 weeks after injection, which could aggravate over time.
(3) Comparative medicine. This model uses histopathology, scanning electron microscopy and other research methods to observe the articular cartilage and articular disc lesions of the model animals at various time periods. It is found that the lesion damage and other methods such as tumor necrosis factor (TNF), occlusal trauma The similarity of joint damage caused by etc. indicates that the model making method has good comparability and meets the basic requirements of animal models. Since no perforation of the joint discs of the model animals was observed, it indicates that the joint disease of this model is in the early and middle stages. Therefore, the established animal model is suitable for the experimental research of early and middle joint disease. The rabbit TMJ OA model induced by this method is simple and easy to make, with typical lesions, and both rabbits and lactate dehydrogenase are easy to obtain, and the price is reasonable. It is an ideal animal model.