初次人工全膝关节置换术后假体周围感染的病原菌分布及药敏分析

DISTRIBUTION AND DRUG SENSITIVITY OF PATHOGENS IN PATIENTS WITH PROSTHETIC JOINT INFECTION AFTER PRIMARY TOTAL KNEE ARTHROPLASTY

目的总结初次人工全膝关节置换术（total knee arthroplasty,TKA）后假体周围感染（prosthetic joint infection,PJI）患者的病原菌分布及其药敏试验结果,为该并发症的诊治提供参考。方法 2003年1月-6月,收治初次TKA术后PJI患者65例（65膝）。男28例,女37例;年龄37-80岁,平均63.2岁。置换术后2周-11年发生PJI,中位时间2.8年。左膝29例,右膝36例。X线片检查示27例有假体松动表现。红细胞沉降率为29.3-73.8 mm/1 h,平均63.2 mm/1 h;C反应蛋白12.5-197.0 mg/L,平均37.4 mg/L。术前取关节液以及术中取关节液及组织标本进行病原菌培养及药敏试验;按照Tsukaya ma等分型标准进行分型。结果患者均确诊为PJI,按照Tsukayama等分型标准：Ⅰ型5例（7.69%）,ⅡA型4例（6.15%）、ⅡB型8例（12.31%）,Ⅲ型3例（4.62%）,Ⅳ型45例（69.23%）。病原菌培养阴性12例,阳性53例;病原菌以革兰阳性球菌（39/53）为主,其中凝固酶阴性葡萄球菌最多（24/53）,其次为金黄色葡萄球菌（12/53）。两种葡萄球菌中耐药菌占61.11%（22/36）。药敏试验结果显示,病原菌对青霉素、红霉素、头孢西丁耐药率高,无万古霉素、利奈唑胺、美罗培南和氟康唑耐药的病原菌。主要病原菌凝固酶阴性葡萄球菌和金黄色葡萄球菌均对青霉素耐药率最高。结论初次TKA后PJI以革兰阳性球菌为主,其对青霉素类和大环内酯类药物耐药率高,入院后可首先经验性选用万古霉素或利奈唑胺,再根据药敏试验结果进行调整,同时需警惕罕见菌和多重耐药菌。

Objective To provide the evidence for diagnosis and treatment of the complication by describing the distribution and drug sensitivity of pathogens in patients with prosthetic joint infection（PJI） after primary total knee arthroplasty（TKA）. Methods Between January 2003 and June 2013, 65 cases（65 knees） with PJI after primary TKA were treated. There were 28 males and 37 females with an average age of 63.2 years（range, 37-80 years）. The median interval between PJI and primary TKA was 2.8 years（range, 2 weeks to 11 years）, including 29 left knees and 36 right knees. Prosthesis loosening could be found in 27 cases by X-ray examination. The average value of C-reactive protein and erythrocyte sedimentation rate was 37.4 mg/L（range, 12.5-197.0 mg/L） and 63.2 mm/1 h（range, 29.3-73.8 mm/1 h） respectively. Preoperative and intraoperative synovial l uid as well as intraoperative tissue samples should be submitted for aerobic and anaerobic culture. The four types of infections were made according to the Tsukayama et al. classii cation standards. Results The patients were all diagnosed as having PJI. There were 5（7.69%） type I infections, 4（6.15%） type IIA, 8（12.31%） type IIB, 3（4.62%） type III, and 45（69.23%） type IV according to the Tsukayama et al. classii cation standard. Bacterial culture results were negative in 12 cases and positive in 53 cases, the main pathogen was Gram-positive cocci（39/53）. The most common organism identii ed was Coagulase-negative Staphylococcus（24/53） followed by Staphylococcus Aureus（12/53）. Resistant bacterium accounted for 61.11%（22/36） of Staphylococcus. These bacterium were all sensitive to vancomycin, linezolid, meropenem, and fluconazole; and highly resistant to erythrocin, penicillin, and cefoxitin. The main pathogenic bacteria of Coagulase-negative Staphylococcus and Staphylococcus aureus had highest resistant rate to penicillin. Conclusion Gram-positive cocci is the main pathogen in patients with PJI after primary TKA, which is highly resistant to penicillin and macrolides. Antibiotic treatment of this complication should be based on the result of drug sensitivity test, vancomycin and linezolid may be used before the result of drug sensitivity test. It is important to pay attention to rare and multiple resistant bacteria.