BACKGROUND:Periprosthetic joint infection is a major complication of total joint arthroplasty, with treatment requiring a two-stage exchange procedure and 6 weeks of systemic antibiotics. However, depending on the infection site, intravenous delivery of antibiotics like vancomycin (VCM) can have poor tissue transferability, thus reducing their therapeutic effect. OBJECTIVE:This study demonstrates the 24-week in vivo release profile and antibacterial activity of VCM from calcium phosphate cement impregnated with VCM (CPC/VCM) and compares them with those from polymethylmethacrylate impregnated with VCM (PMMA/VCM). METHODS:Rats were implanted with the test specimens between the fascia and quadriceps. After implantation for 24 weeks, the test specimens were removed and residual VCM was extracted to calculate the concentration of VCM released into rat tissues. We also examined the antibacterial activity of releasable VCM from the removed test specimens by placing them directly onto the surface of agar. RESULTS:CPC/VCM released greater concentrations of VCM for a longer period of time within the 24 weeks than PMMA/VCM. Moreover, CPC/VCM released 1.4 to 26.1-fold more VCM than PMMA/VCM. Using Staphylococcus aureus, antibacterial activity was logarithmically correlated with VCM concentration across the entire concentration range tested (12.5–800 μg/mL). While the area within which inhibition was observed—the inhibition zone—for both CPC/VCM and PMMA/VCM formed and gradually shrank with time after implantation, that for CPC/VCM was significantly larger than that for PMMA/VCM in each week after implantation. CONCLUSION:CPC/VCM releases greater amounts of VCM with antibacterial activity for longer periods of time than PMMA/VCM, suggesting that CPC is effective for facilitating the release of antibiotics for local action in patients with established postoperative infection.

中文翻译：

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磷酸钙骨水泥中万古霉素在体内的长期抗菌活性

背景：假体周围感染是全关节置换术的主要并发症，治疗需要两阶段置换手术和 6 周的全身抗生素治疗。然而，根据感染部位的不同，万古霉素 (VCM) 等抗生素的静脉给药可能具有较差的组织转移性，从而降低其治疗效果。目的：本研究展示了 VCM 浸渍磷酸钙水泥 (CPC/VCM) 中 VCM 的 24 周体内释放曲线和抗菌活性，并将其与浸渍 VCM 的聚甲基丙烯酸甲酯 (PMMA/VCM) 进行了比较。方法：将试件植入大鼠筋膜与股四头肌之间。植入24周后，取出试验样品，提取残留的VCM，计算释放到大鼠组织中的VCM浓度。我们还通过将可释放的 VCM 直接放在琼脂表面上，从取出的试样中检测了它们的抗菌活性。结果：与 PMMA/VCM 相比，CPC/VCM 在 24 周内释放更高浓度的 VCM 的时间更长。此外，CPC/VCM 释放的 VCM 比 PMMA/VCM 多 1.4 到 26.1 倍。使用金黄色葡萄球菌，在整个测试浓度范围 (12.5–800 μg/mL) 内，抗菌活性与 VCM 浓度呈对数相关。虽然观察到抑制的区域 - 抑制区 - 对于 CPC/VCM 和 PMMA/VCM 都形成并在植入后随着时间逐渐缩小，植入后每周 CPC/VCM 显着大于 PMMA/VCM。结论：与 PMMA/VCM 相比，CPC/VCM 释放更多的具有抗菌活性的 VCM 持续时间更长，这表明 CPC 可有效促进抗生素释放，以促进术后感染患者的局部作用。