| Total hip arthroplasty(THA) is currently used methods to treat severe hip disease. As artificial hip prosthesis improvement and operation technology development, such as surgery generally high satisfaction. Artificial joint replacement has become a successfully, cost-effective means of treatment, can effectively improve the quality of life of patients. Under the precursor of effective in preventing infection and improve the prosthesis fatigue resistance,aseptic loosening of prosthesis becomes the main reason for the effect of artificial joint use fixed number of year( of operation failure 75%).So if we can in early of aseptic prosthetic loosening occurred and timely intervention is expected to reverse or slow down the occurrence of prosthesis loosening.X ray as a kind of ionizing radiation, in many fields, including medicine, has been widely used. Our previous study found that a low dose X-ray irradiation can promote the proliferation and differentiation of osteoblast. In addition, the low dose X-ray irradiation has obvious inhibiting inflammation effect, therefore low dose X-ray irradiation could help in early in the aseptic prosthetic loosening of prosthesis to reverse the surrounding tissue reaction. or delay the onset of prosthesis loosening.At present, the study of early diagnosis of prosthetic loosening,and intervention treatment is relativelyless, and After low dose X-ray radiation prosthesis surrounding tissue in live animals,, the multiple tissues around the prosthesis, including bone, changes remains unclear This study to establish a rabbit model of prosthesis loosening and With medical linear accelerator used 0.5Gy, 1.0 Gy doses of x-rays to radiate tissue surrounding the prosthesis to observe the prosthetic loosening of minor early serological and histological changes, and research related serological indexes changed after the X-ray irradiation, for further understanding of prosthesis loosening early serological and histological changes and the low dose ionizing radiation biological effect of intervention.This experiment is divided into two parts:Part I Establish effectively observe early aseptic prosthetic looseningearly in a rabbit modelObjective: Simulation of wear particles generated early micro environment around the prosthesis by Ti particle injection, then observe the early changes of tissues surrounding the loose prosthesis and serological related serological indicators, clear the practical effectiveness of the model and can be detected,, in order to provide the experimental basis for further study the low dose X-ray irradiation intervention factors.Methods: 16 healthy male adult New Zealand white rabbit, only 2 ~ 2.5 kg weight. Randomly divided into experimental group and control group, each group of eight only. Groups of animals in the medial patellar incision, dislocation of patella, distal femur, between bilateral femoral condyle nest in front of the 2 mm do A bone tunnel, then implant one 3.2 mm long, 15 mm in diameter with hydroxyl apatite layer of titanium prosthesis, A group animals left leg implanted false devices for first in the tunnel injection of 0.2 ml concentration is 1.0 g/ml Ti particles suspension, group B animals left leg after the injection amount of saline solution into the same specification prosthesis in comparison. Don’t ban on physical activity after surgery. Intramuscular injection of penicillin postoperative 1 ~ 3 days, 100000 u/Kg; Respectively 0, 2 w, 4 w and 8 w d four time point liquid, 8 w kill animals for femoral biological specimens. ELISA method to detect the contents of ALP, PINP, CTX- 1; Micro-CT used to detect the change of bone tissue around implant; Compare two groups of biomechanics changes and hard tissue slice observation prosthesis surrounding tissues.Results: the experimental group compared with control group: ALP, PINP, CTX- 1 there was no significant difference in each period. Group A prosthetic anisotropy was lower than that in group B, the difference is statistically significant,Bone trabecular thickness(Tb. Th) also has a downward trend.But the difference of the bone trabecular number(Tb. N) 、bone volume fraction(BV/TV) and bone mineral density(BMD) were no statistically significant。Biopsy results:Group A prosthesis with obvious inflammatory membrane formed around,at the same time Ti particles around the fibrous tissue of mineralization。Conclusion: In rabbit prosthesis local inflammatory reaction, at this time in serological osteogenesis, bone metabolism index did not change,the bone mass around the implant bone without falling and implant of strength under the condition of normal performance,We can use this characteristic that Ti particles surrounding mineralized fiber can reduce the anisotropy of trabecular bone around implant to indirectly reflect the degree of local inflammation。Biomechanical testing there was no significant difference between the two groups.Part II Low dose X-ray irradiation on early prosthesis loosening theimpact of surrounding tissue structureObjective:After low dose X-ray irradiation, study the change of bone tissue surrounding the prosthesis and the specific serological indexesMethods: using simulation Kubo animal models,to establish a similar to group A prosthesis loosening rabbit model as C, D group, each group of eight, as exposure group C, D group as control group.Two days after the operation,With medical linear accelerator used 1.0 G y doses of x-rays to single local radiate bone tissue surrounding the prosthesis in Group C animals。Don’t ban on physical activity after surgery. Intramuscular injection of penicillin postoperative 1 ~ 3 days, 100000 u/Kg; Respectively 0, 2 w, 4 w and 8 w d four time point liquid, 8 w kill animals for femoral biological specimens. ELISA method to detect the contents of ALP, PINP, CTX- 1; Micro-CT used to detect the change of bone tissue around implant; Compare two groups of biomechanics changes and hard tissue slice observation prosthesis surrounding tissues.Results: in different periods, two groups of animals in the peripheral blood of qing dynasty there was no significant difference in the content of CTX- 1; PINP in 0 w and 8 w period PINP content had no significant difference, and 2 w period PINP content had significant difference(P < 0.05), and the exposure group is higher than not illuminate. Micro CT results show that the irradiation group of trabecular bone around implant anisotropy is significantly higher than the control group。Hard tissue section test results in exposure group the inflammation reaction around the prosthesis significantly reduce. Biomechanical testing there was no significant difference between the two groups.Conclusion: Low dose X-ray irradiation make the animal model of PINP content increased in peripheral blood of qing dynasty, without affecting the broken bone metabolism index CTX- 1,To facilitate bone formation without affecting bone resorption。While low doses of x-rays can effectively suppress the local inflammatory response induced by wear particles, improve pathological characteristics of tissue surrounding the prosthesis. |
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