Hendriks Johannes G E, Neut Daniëlle, van Horn Jim R, van der Mei Henny C, Busscher Henk J
Department of Biomedical Engineering, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
J Biomed Mater Res B Appl Biomater. 2003 Jan 15;64(1):1-5. doi: 10.1002/jbm.b.10391.
Gentamicin is added to polymethylmethacrylate bone cements in orthopedics as a measure against infection in total joint arthroplasties. Numerous studies have been published on gentamicin release from bone cements, but none have been able to estimate the local concentrations in the prosthesis-related interfacial gap, present after implantation. The aim of this study was to develop a method allowing determination of antibiotic release in such a gap. Two-hundred-micrometer-wide gaps with a volume of 6 microl and a surface area of 0.6 cm2 were created by inserting stainless-steel strips in gentamicin-loaded bone cement plugs prior to polymerization. After hardening, the gap surface was exposed to 6 microl or 10 ml of phosphate-buffered saline. Within 2 h, gentamicin concentrations in the gaps reached around 4000 microg/ml for 4 different CMW and Palamed cements and 2500 microg/ml for Palacos R. Concentrations measured in the larger volume were several hundred times lower than in the gaps. This simulated prosthesis-related interfacial gap model offers new insights in the clinical efficacy of antibiotic-loaded bone cements. It is demonstrated that concentrations up to 1000-fold the antibiotic resistance levels for most bacterial strains causing implant infection can be achieved in a realistic in vitro model.
庆大霉素被添加到骨科用的聚甲基丙烯酸甲酯骨水泥中，作为全关节置换术中预防感染的一种措施。关于庆大霉素从骨水泥中的释放情况，已经发表了大量研究，但尚无研究能够估算植入后假体相关界面间隙中的局部浓度。本研究的目的是开发一种能够测定此类间隙中抗生素释放情况的方法。在聚合前，通过将不锈钢条插入负载庆大霉素的骨水泥塞中，制造出宽度为200微米、体积为6微升、表面积为0.6平方厘米的间隙。硬化后，将间隙表面暴露于6微升或10毫升磷酸盐缓冲盐水中。在2小时内，对于4种不同的CMW和Palamed骨水泥，间隙中的庆大霉素浓度达到约4000微克/毫升，对于Palacos R骨水泥则为2500微克/毫升。在较大体积中测得的浓度比间隙中的浓度低数百倍。这种模拟的假体相关界面间隙模型为负载抗生素骨水泥的临床疗效提供了新的见解。结果表明，在一个逼真的体外模型中，可以达到对大多数引起植入物感染的细菌菌株而言高达抗生素耐药水平1000倍的浓度。
