The infection rate of total knee arthroplasty is still high, in spite of the high success of this surgical procedure. The use of an antibiotic-loaded temporary spacer made of poly(methyl methacrylate) (PMMA) has been proposed to treat infected knee arthroplasties.

This study was aimed at comparatively investigating, on a molecular scale, two types of spacers from the same manufacturer (Spacer K and Vancogenx-space knee, Tecres, Italy), which differ for the added antibiotic (gentamicin sulphate in Spacer K and gentamicin sulphate + vancomycin hydrochloride in Vancogenx). Raman spectroscopy was used to gain more insights into the possible effects of the antibiotic on the spacer composition and polymer structure both in the new components and after in vivo use. Vancogenx was found to contain a lower residual MMA content than Spacer K (about 0.15% versus 0.4%). The former contained a higher amount of isotactic stereosequences than the latter, while the syndiotactic content (the prevailing component) was not significantly different in the two prostheses. The presence of vancomycin hydrochloride influenced not only the degree of polymerization and PMMA tacticity and crystallinity, but in turn also the wear behavior. Actually, Spacer K retrievals were found more affected by in vivo implantation than Vancogenx-space knee ones, revealing slight variations in polymer tacticity and crystallinity and relative radiopacifier content, besides release of MMA and additives of polymerization. However, these changes did not appear worrisome, due to the temporary nature of the prosthesis. In view of these results, the addition of vancomycin hydrochloride could offer an advantage, in spite of the higher costs requested and the potential risks of its unselective use.

尽管这种手术方法非常成功，但全膝关节置换术的感染率仍然很高。已提出使用由聚甲基丙烯酸甲酯（PMMA）制成的加载有抗生素的临时间隔物来治疗感染的膝关节置换术。

这项研究的目的是在分子水平上比较研究同一制造商（Spacer K和Vancogenx-space Knee，Tecres，意大利）的两种间隔物，两种间隔物在添加的抗生素（Spacer K中的硫酸庆大霉素和硫酸庆大霉素）方面有所不同+ Vancogenx中的万古霉素盐酸盐）。拉曼光谱法用于获得新成分和体内使用后抗生素对间隔物组成和聚合物结构的可能影响的更多见解。发现Vancogenx的残留MMA含量低于间隔剂K（相对于间隔剂K约为0.15％0.4％）。前者的等规立体序列数量要多于后者，而间规的内容（主要成分）在两种假体中没有显着差异。盐酸万古霉素的存在不仅影响聚合度，PMMA的立构规整度和结晶度，而且还影响其磨损性能。实际上，发现Spacer K检索受体内影响更大植入物比Vancogenx膝关节植入物的植入性好，除了释放MMA和聚合添加剂外，还显示出聚合物的立构规整度和结晶度以及相对的不透射线的含量略有变化。但是，由于假体的暂时性，这些变化似乎并不令人担忧。鉴于这些结果，尽管要求的成本较高以及非选择性使用的潜在风险，但添加万古霉素盐酸盐仍可提供优势。