Craig Matthew R, Poelstra Kornelis A, Sherrell J Christopher, Kwon Michael S, Belzile Etienne L, Brown Thomas E
Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA 22908, USA.
J Orthop Res. 2005 Sep;23(5):1100-4. doi: 10.1016/j.orthres.2005.03.007.
Infection of biomaterial implants is an expensive and devastating complication of orthopaedic surgery historically ranging from less than 1% in primary total knee arthroplasty (TKA) to 10% in revision TKA. An in vivo animal model was developed to test the efficacy of innovative therapies for the prevention of biomaterial centered infections caused by methicillin-resistant Staphylococcus aureus bacteria (MRSA). Twenty-two New Zealand White rabbits were used in this study. After proper anesthesia, a stainless-steel screw with a high molecular weight polyethylene (UHMWPE) washer was cemented in a defect created in the intra-articular, non-articulating portion of the lateral femoral condyle of each knee. After closure of the joint capsule, each knee was inoculated with 0, 10(2), 10(3), or 10(4) colony forming units (CFU) of MRSA. Animals were sacrificed after 7 days at which time joint aspirate, tissues and biomaterial samples were examined for evidence of infection. A total of 42 knees were used for analysis. When saline was injected into the knee, 0/10 of the knees demonstrated evidence of biomaterial centered infection (with the contralateral knee receiving 10(4)CFU MRSA). Four of 10 knees developed a biomaterial centered infection when 10(2)CFU MRSA was introduced. Seven out of 10 knees developed a biomaterial centered infection when either 10(3) or 10(4)CFU MRSA was injected. No evidence of septicemia (positive blood cultures) was found in any animal. This rabbit knee model utilizes commonly employed inexpensive orthopaedic implant materials in an in vivo milieu and provides an effective method for the evaluation of treatments for biomaterial centered infections.
生物材料植入物感染是骨科手术中一种代价高昂且极具破坏性的并发症，历史上其发生率在初次全膝关节置换术（TKA）中低于1%，在翻修TKA中为10%。开发了一种体内动物模型，以测试创新疗法预防耐甲氧西林金黄色葡萄球菌（MRSA）引起的以生物材料为中心的感染的疗效。本研究使用了22只新西兰白兔。在适当麻醉后，将带有超高分子量聚乙烯（UHMWPE）垫圈的不锈钢螺钉用骨水泥固定在每个膝关节外侧股骨髁关节内非关节部分制造的缺损处。关闭关节囊后，每个膝关节接种0、10²、10³或10⁴个MRSA菌落形成单位（CFU）。7天后处死动物，此时检查关节抽吸物、组织和生物材料样本以寻找感染证据。总共42个膝关节用于分析。当向膝关节注射生理盐水时，10个膝关节中有0个显示出以生物材料为中心的感染证据（对侧膝关节接种10⁴CFU MRSA）。当引入10²CFU MRSA时，10个膝关节中有4个发生了以生物材料为中心的感染。当注射10³或10⁴CFU MRSA时，10个膝关节中有7个发生了以生物材料为中心的感染。在任何动物中均未发现败血症证据（血培养阳性）。这种兔膝关节模型在体内环境中使用常用的廉价骨科植入材料，并为评估以生物材料为中心的感染的治疗方法提供了一种有效方法。
