Behrens Julika Johanna, Franz Alexander, Schildberg Frank Alexander, Rudowitz Markus, Grote Stefan, Fröschen Frank Sebastian
Department of Orthopedics and Trauma Surgery, University Hospital Bonn, 53127 Bonn, Germany.
Department of Trauma and Orthopedic Surgery, BG Klinik Ludwigshafen, 67071 Ludwigshafen, Germany.
Antibiotics (Basel). 2025 Jul 24;14(8):742. doi: 10.3390/antibiotics14080742.
: Two-stage revision with an antibiotic-loaded, temporary static cement spacer is a common treatment for periprosthetic joint infection (PJI) of the knee. However, limited data exists on in vivo antibiotic elution kinetics after spacer implantation. This pilot study uses the technique of microdialysis (MD) to collect intra-articular knee samples. The aim was to evaluate MD as an intra-articular sampling method to detect spacer-eluted antibiotics within 72 h after surgery and to determine whether they show specific elution kinetics. : Ten patients (six male, four female; age median 71.5 years) undergoing two-stage revision for knee PJI were included. A MD catheter was inserted into the joint during explantation of the infected inlying implant and implantation of a custom-made static spacer coated with COPAL cement (0.5 g gentamicin (G) and 2 g vancomycin (V)). Over 72 h postoperatively, samples were collected and analyzed for spacer-eluted antibiotics, intravenously administered antibiotics (e.g., cefazolin and cefuroxime), metabolic markers (glucose and lactate), and Interleukin-6 (IL-6). Local and systemic levels were compared. : All catheters were positioned successfully and well tolerated for 72 h. Antibiotic concentrations in MD samples peaked within the first 24 h (G: median 9.55 µg/mL [95% CI: 0.4-17.36]; V: 37.57 µg/mL [95% CI: 3.26-81.6]) and decreased significantly over 72 h (for both < 0.05, G: 4.27 µg/mL [95% CI: 2.26-7.2]; V: 9.69 µg/mL [95% CI: 3.86-24]). MD concentrations consistently exceeded blood levels ( < 0.05), while intravenously administered antibiotics showed higher blood concentrations. Glucose in MD samples decreased from 17.71 mg/dL to 0.89 mg/dL ( < 0.05). IL-6 and lactate concentrations showed no difference between MD and blood samples. : Monitoring antibiotics eluted by a static spacer with intra-articular MD for 72 h is feasible. Gentamicin and vancomycin levels remained above the minimal inhibitory concentration. Differentiating infection from surgical response using metabolic and immunological markers remains challenging. Prolonged in vivo studies with MD are required to evaluate extended antibiotic release in two-stage exchanges.
采用载抗生素的临时静态骨水泥间隔物进行两阶段翻修是膝关节假体周围感染（PJI）的常见治疗方法。然而，关于间隔物植入后体内抗生素洗脱动力学的数据有限。这项前瞻性研究采用微透析（MD）技术收集膝关节内样本。目的是评估MD作为一种关节内采样方法，用于检测术后72小时内间隔物洗脱的抗生素，并确定它们是否呈现特定的洗脱动力学。
纳入10例接受膝关节PJI两阶段翻修的患者（6例男性，4例女性；年龄中位数71.5岁）。在取出感染的内置植入物并植入涂有COPAL骨水泥（0.5 g庆大霉素（G）和2 g万古霉素（V））的定制静态间隔物期间，将MD导管插入关节。术后72小时内，收集样本并分析间隔物洗脱的抗生素、静脉注射的抗生素（如头孢唑林和头孢呋辛）、代谢标志物（葡萄糖和乳酸）以及白细胞介素-6（IL-6）。比较局部和全身水平。
所有导管均成功放置且72小时内耐受性良好。MD样本中的抗生素浓度在最初24小时内达到峰值（G：中位数9.55 µg/mL [95% CI：0.4 - 17.36]；V：37.57 µg/mL [95% CI：3.26 - 81.6]），并在72小时内显著下降（两者均<0.05，G：4.27 µg/mL [95% CI：2.26 - 7.2]；V：9.69 µg/mL [95% CI：3.86 - 24]）。MD浓度始终超过血液水平（<0.05），而静脉注射的抗生素血液浓度更高。MD样本中的葡萄糖从17.71 mg/dL降至0.89 mg/dL（<0.05）。IL-6和乳酸浓度在MD样本和血液样本之间无差异。
使用关节内MD监测静态间隔物洗脱的抗生素72小时是可行的。庆大霉素和万古霉素水平保持在最低抑菌浓度以上。使用代谢和免疫标志物区分感染与手术反应仍然具有挑战性。需要进行更长时间的MD体内研究，以评估两阶段置换中抗生素的延长释放情况。
