兔膝关节置换假体感染模型的建立

Objective An in vivo animal model was developed to test the efficacy of innovative therapies for the prevention of biomaterial centered infections caused by E. Staphylococcus. Methods Thir-ty-two New Zealand white rabbits were used in this study. After proper anesthesia, a knee prosthesis made by UHMWPE was cemented in the surface of tibia of knee. After 1 week of operation, the operated knee was inoculated with 0, 1×104, 1×106, and 1×108 colony forming units (CFU) of E. Staphylococcus. Animals were sacrificed after 1 week at which time tissues and biomaterial samples were examined for evidence of infec-tion. Joint tissue, implant and joint fluid were tested for the number of bacteria. The joint and implant sam-ple was examined by X-ray, MR, CLSM and pathological examination. Results A total of 32 knees were used for analysis. When saline was injected into the knee, 0 of the knees demonstrated evidence of biomate-rial centered infection. When 1×106 CFU of E. Staphylococcus was injected into the knee, all knees devel-oped a biomateriai centered infection. Evidence of septicemia (positive blood cultures) was found in a rabbit inoculated with 108 CFU of E. Staphylococcus. The infection rate was positively correlated with the amount of the E. Staphylococcus inoculated (R2=0.9939). Gross observation showed a great amount of abscess covered the surface of implant. The joint synovial membrane was erythrogenic. CLSM showed a lot of bacteria were adhesive to the surface of implant and there were films of ESS substance on the surface. Histological exami-nation showed an acute infection. The quantities analysis showed the number of bacteria in joint fluid is sig-nificantly high than that of on the surface of implant and in the joint tissue. Conclusion This rahbit knee infection model mimic clinical situation. It is a successful model and provides an effective method for the e-valuation of new treatment for biomaterial centered infection.

A novel total knee arthroplasty infection model in rabbits