一期翻修治疗全膝关节置换术后假体周围慢性感染的实验研究

 目的 通过动物实验探讨一期翻修治疗耐甲氧西林金黄色葡萄球菌所致假体周围慢性感染的疗效。方法 48只新西兰兔行右膝关节置换,术后 4周接种耐甲氧西林金黄色葡萄球菌建立假体周围感染模型。接种 4周后,随机分为两组院实验组一期翻修,对照组行二期翻修第一步抗生素骨水泥填充术。监测置换前,翻修前,翻修后 1、3、5、7天和 2、4、6、12周的 C反应蛋白和红细胞沉降率。翻修后 12周处死,膝关节取样进行细菌培养。培养结果阳性为再感染,阴性为治愈。结果 5只实验动物出组。实验组再感染率为 22.7%(5/22),对照组再感染率为 14.3%(3/21), 两组差异无统计学意义(χ²= 0.102,P=0.750)。翻修后两组 C反应蛋白均升高,第 3天达峰值,第 4周恢复至初次置换前水平,两组差异无统计学意义(F=0.157,P=0.694)。翻修后两组红细胞沉降率均升高,第 5天达峰值,第 12周恢复至初次置换前水平,两组差异无统计学意义(F=0.936,P=0.339)。结论 在明确菌种及其抗菌谱的前提下,治疗由高毒力细菌引起的膝关节假体周围慢性感染,一期翻修的近期疗效与二期翻修无差异。

Single-stage revision total knee arthroplasty for infection resulting from methicillin-resistant Staphylococcus aureus in rabbits

Objective To 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. Methods A 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. Results Five 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). Conclusion Though 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.