【Animal modeling】-Establishment of periprosthetic infection model after total knee arthroplasty in New Zealand rabbits

  Objective To explore the method and feasibility of establishing a periprosthetic infection model after total knee arthroplasty in New Zealand rabbits.

  Methods A total of 48 healthy New Zealand rabbits were selected and randomly divided into 3 groups: experimental group (periprosthesis infection group), control group (prosthesis uninfected group) and blank control group (sham operation group), 16 rabbits in each group; experimental group New Zealand rabbits were injected with 0.5 mL of Staphylococcus aureus suspension (1 × 107 CFU/mL) 7 days after total knee arthroplasty in the left knee joint, and the control group was treated with left knee arthroplasty 7 days after surgery New Zealand rabbits were injected with 0.5 mL of normal saline into the joint cavity, and the blank control group received no treatment after capsulotomy and suture of the left knee joint. Hematological examinations were performed before and 7 and 21 days after operation in each group, and X-ray examination, bacteriological and pathological examinations were performed at 21 days after operation.

  Results At 21 days after operation, the survival rate of the experimental group was 87.5% (14/16), and the survival rate of the control group and blank control group was 100%. X-ray examination at 21 days after operation showed that both the experimental group and the control group showed that the joint prosthesis was in place, and there was no looseness around the prosthesis. The soft tissue around the joint in the experimental group was swollen, but the soft tissue around the joint in the control group and the blank control group was not significantly swollen; hematology The test results showed that the total number of white blood cells (WBC), ESR and CRP in the experimental group were higher than those in the control group and the blank control group, with statistical significance (P < 0.05). 100% (14/14), 1 case was positive for bacterial culture in the control group, and the infection rate was 6.3% (1/16); the bacterial culture in the blank control group was negative, and the infection rate was 0% (0/16); pathological examination It was shown that there was a large amount of inflammatory cell infiltration around the prosthesis and surrounding tissues in the experimental group; there was no inflammatory cell infiltration in the surrounding and surrounding tissues of the prosthesis in the control group and blank control group.

  Conclusion Seven days after total knee arthroplasty in New Zealand rabbits, intra-articular injection of 0.5 mL of Staphylococcus aureus suspension can successfully establish an infection model after artificial joint arthroplasty.