Single-stage revision total knee arthroplasty for infection resulting from methicillin-resistant Staphylococcus aureus in rabbits / 中华骨科杂志

ABSTRACT

ObjectiveTo compare the efficacy of single-stage and two-stage revision prosthesis-relative chronic infection causing by methicillin-resistant Staphylococcus aureus(MRSA) after total knee arthroplasty(TKA) in rabbits, and evaluate the clinical feasibility of single-stage revision TKA. MethodsA new kind of prosthesis was implanted into the right knee joints of 48 New Zealand white rabbits following proper anesthesia. After 4 weeks, the dose of 5×105 colony forming unit MRSA was inoculated into every knee to establish prosthesis joint infection model. The rabbits were divided into 2 groups randomly experimental and control group. Four weeks after inoculation, the treatments of the experimental and control group were singlestage and two-stage revision respectively. The levels of serum C-reaction protein (CRP) and Erythrocyte sedimentation rate (ESR) were monitored in ten phase, i.e. prior to primary arthroplasty and revision, at 1, 3, 5, 7days, and 2, 4, 6, 12 weeks after revision. Twelve weeks after revision, animals were sacrificed and joint samples were collected for bacterial culture. The positive results were judged as reinfection, and the negative results were judged as successful healing. ResultsFive rabbits were excluded out of the group for some reasons. The recurrence rates of infection in the experimental group and control group were 22.7％ (5/22) and 14.3％(3/21) respectively after revision. The difference between them was statistically insignificant(χ2=0.102,P=0.750). The levels of serum CRP of the two groups raised, and reached their peaks at 3 days, then dropped into the normal level prior to primary arthroplasty at 4 weeks after revision. The difference between them was statistically insignificant (F=0.157, P=0.694). The ESR levels of the two groups elevated after revision, and reached their peaks at 5 days, then declined slowly into the original level prior to primary arthroplasty at 12 weeks. The difference between them was statistically insignificant (F=0.936,P=0.339). ConclusionThough the prosthesis-relative chronic infection caused by high virulence organism after TKA, the short-term efficacy of single-stage revision is similar to that of two-stage if the stain of pathogenic bacteria and its spectrum are obtained.