Molecular diagnostics in periprosthetic joint infection

Periprosthetic joint infection (PJI) is a significant and costly challenge to the orthopedic community. The lack of a gold standard for diagnosis remains the biggest obstacle in the detection and subsequent treatment of PJI. Molecular markers in the serum and joint fluid aspirate hold immense promise to enhance the development of a firm diagnostic criterion. The primary goal is one marker with high sensitivity and specificity. Here, we review our current research efforts in the field of molecular markers: C-reactive protein, erythrocyte sedimentation rate, white blood cells, and leukocyte esterase. Each marker has been studied to determine its sensitivity, specificity, and positive and negative predictive values in diagnosing PJI.     

关节滑液检测在关节假体周围感染诊断中的研究进展

关节假体周围感染(periprosthetic joint infection,PJI)是人工关节置换术后可能发生的一种严重并发症,其导致的严重后果,无论对于医生还是患者来说,都很难接受。目前,由于多种不确定因素的存在,PJI诊断的准确性较低。传统的血清学检查、影像学检查有一定的价值,但是易受全身情况的影响,导致特异性不高。为了正确诊断关节假体周围感染,不同学科的研究人员采用各种不同的方法进行了大量的诊断研究,并取得了丰富的成果。近年来,关节滑液炎性标志物检测、分子生物学方法等被研究证实具有较高的敏感性和特异性。因此,关节滑液CRP、-防御素、白细胞酯酶、PCR技术等被广泛研究,期望能从中找到诊断关节假体周围感染的特异性指标,提高临床诊断的准确性。     

Optimization of periprosthetic culture for diagnosis of Propionibacterium acnes prosthetic joint infection

Propionibacterium acnes is increasingly recognized as an important agent of prosthetic joint infection (PJI). However, the optimum culture conditions for recovery of this organism from PJI specimens have not been determined. By applying a prolonged 28-day culture incubation to all periprosthetic specimens received for bacterial culture from 198 revision arthroplasty procedures, we retrospectively determined that a 13-day culture incubation period is necessary for the recovery of P. acnes from patients with PJI. Incubation beyond this period was associated with increasing recovery of nondiagnostic isolates: 21.7% of P. acnes isolates believed to be clinically unimportant were recovered after 13 days of incubation. Importantly, a diagnosis of P. acnes PJI would have been missed in 29.4% of patients had extended culture incubation been applied only to anaerobic culture media. Although specimens from P. acnes PJIs were more commonly associated with the presence of ≥ 2 culture media positive for growth, acute inflammation (≥ 5 neutrophils/high-power field) was observed in only 40% of patients with PJIs that had more than one specimen submitted for bacterial culture. These results support the need for a minimum culture incubation period of 13 days to be applied to both aerobic and anaerobic culture media for all periprosthetic specimens. Optimal recovery of infecting organisms from PJI specimens will be an important component in generating a universal definition for PJI due to indolent agents of infection, such as P. acnes.     

关节置换术后假体周围感染临床诊断与治疗的研究现状

目的:总结髋、膝关节置换术后假体周围感染(PJI)的临床诊断,以及保留假体清创术和翻修手术治疗PJI的研究现状。方法:在中国知网、万方数据、PubMed等中、英文数据库,以"假体周围感染""诊断""清创""再手术"以及"periprosthetic joint infection""diagnosi""debridem...     

The utility of dithiothreitol treatment of periprosthetic tissues and explanted implants in the diagnosis of prosthetic joint infection

PurposeThe methods used for the processing of periprosthetic tissues and explanted implants to improve culture outcome especially in biofilm mediated prosthetic joint infections (PJIs) are still debated upon. Studies have reported that Dithiothreitol (DTT) pretreatment of infected devices gives similar results as sonication. However, none of them evaluated the DTT treatment of periprosthetic tissues and explanted implants in the same cohort. We evaluated the diagnostic utility of DTT treatment of periprosthetic tissue and explanted implants, as compared to the normal saline treatment of periprosthetic tissues and sonication of explanted implants for the diagnosis of PJI.MethodsSeventy-three revision arthroplasty cases were prospectively included in this study. Three to five tissue specimens and the explanted implants were collected from each patient. Periprosthetic tissue samples were processed by both normal saline and DTT treatments. Explanted implants were subjected to both DTT treatment and sonication. Musculoskeletal Infection Society (MSIS) PJI criteria was used as the reference standard for the diagnosis of PJI.ResultsOf the 73 cases enrolled, 34 had PJI and 39 were aseptic failures. The sensitivity of DTT treated periprosthetic tissue culture (PTC) and saline treated PTC was similar (66.6% vs 58.8%, P = 0.25). The specificity of both was 100%. Sonication and DTT treatment of explanted implants showed comparable sensitivity (85.3% vs 82.4%) and specificity (100% vs 97.4%), P > 0.99. Compared to DTT treated PTC, culture of DTT treated explanted implants significantly improved the diagnosis of PJI (P = 0.03).ConclusionsWe could verify that DTT can be used to improve culture outcome in laboratories where biofilm detaching sonication techniques are not available for infected implants. In addition, we showed that it is possible to use DTT for treating tissue biopsies, but larger studies are required to confirm our findings.     

Origin and characteristics of haematogenous periprosthetic joint infection

ObjectivesRecognition of infectious origin of haematogenous periprosthetic joint infections (PJI) is crucial. We investigated the primary focus and characteristics of haematogenous PJI.MethodsConsecutive patients who presented with haematogenous PJI between 01/2010 and 01/2018 were retrospectively analysed. Haematogenous PJI was defined by diagnosis of infection ≥1 month after surgery, acute manifestation after a pain-free period and positive blood or prosthetic-site culture and/or evidence of distant infectious focus consistent with the pathogen. Fisher's exact, Student's t and Mann–Whitney U tests were used, as appropriate.ResultsA total of 106 episodes of PJI were included, involving 59 knee, 45 hip, one shoulder and one elbow prostheses. The median time from last surgery until haematogenous PJI was 47 months (range, 1–417 months). The pathogen was identified in 105 episodes (99%), including Staphylococcus aureus (n = 43), streptococci (n = 32), enterococci (n = 13), Gram-negative bacteria (n = 9) and coagulase-negative staphylococci (n = 8). Gram-negative bacteria were significantly more often found in hip joints than in knee joints. Blood cultures grew the pathogen in 43 of 70 episodes (61%). The primary infectious focus was identified in 72 episodes (68%) and included infections of intravascular devices or heart valves (22 episodes), skin and soft tissue (16 episodes), the oral cavity (12 episodes), urogenital (12 episodes) or gastrointestinal tract (seven episodes) and other sites (three episodes).ConclusionsIn acute PJI manifesting after a pain-free period, the haematogenous infection route should be considered and the primary infectious focus should be actively searched for. The cardiovascular system, skin and soft tissue, oral cavity, urogenital and gastrointestinal tracts were common origins of haematogenous PJI.     

不同生物标记物预测关节置换后假体周围感染与无菌性松动的效能分析

背景：假体周围感染是关节置换后一种难以处理的并发症,早期诊断是治疗的关键,寻找到一种反应快速的、高敏感度和特异度的分子生物学标志物可显著优化假体周围感染的诊断过程。 目的：监测血降钙素原、白细胞介素6和脂多糖结合蛋白水平,并与血白细胞计数和C-反应蛋白水平比较,明确上述指标鉴别关节置换后感染的敏感度和特异度。 方法：招募2008年1月至2013年12月因关节置换后疼痛就诊于济宁医学院附属医院的患者81例。所有的感染患者修复手术分为两期,一期彻底清创,安装临时占位器,平均3个月后进行二期重建。术前1 d采集静脉血,检测降钙素原、白细胞介素6、脂多糖结合蛋白、白细胞计数和C-反应蛋白水平,术中采集滑膜及假体周围假包膜的样本,行细菌及组织形态学检查。应用受试者工作特征曲线计算敏感度和特异度。 结果与结论：单因素方差分析结果显示,脂多糖结合蛋白的受试者工作特征曲线最大,为0.962,95%置信区间0.924-1.000,诊断价值最佳,此时的临界值为23.5 μg/L,表明术前患者血脂多糖结合蛋白超过23.5 μg/L时,诊断为假体周围感染的可能最大;其次是C-反应蛋白,其受试者工作特征曲线为0.871;而白细胞的受试者工作特征曲线接近0.5,术前根据白细胞计数诊断假体周围感染的价值不大。提示检测脂多糖结合蛋白对于关节置换后假体周围感染的诊断具有良好的应用前景,它对假体周围感染的阳性预测率和阴性预测率均很高。 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

血清学炎性指标作为早期诊断关节置换术后假体周围感染的研究现状

作为人工关节置换术后的灾难性并发症,关节假体周围感染目前尚无完美的敏感性和特异性血清学炎性指标。所以假体周围感染的早期诊断依然是骨科医师面对的挑战。本文筛选了目前临床用于人工关节假体周围感染的一些血清学炎性指标,予以综述。希望为临床骨科医师早期诊断人工关节假体周围感染提供参考。     

Evaluation of the use of sonication of retrieved implants for the diagnosis of prosthetic joint infection in a routine setting

In order to evaluate the usefulness of sonication of retrieved implants for the diagnosis of prosthetic joint infection (PJI) in a large group of patients in a routine setting, we designed a 3-year retrospective study. Patients were classified into two groups: those meeting the clinical criteria of PJI and those that did not (control group). Two hundred patients and 276 samples were included. The types of infection were early (n?=?44), delayed (n?=?53), positive intraoperative cultures (n?=?13) and late-acute (n?=?8). The culture sensitivities of sonicate fluid, periprosthetic tissue, synovial fluid and combination of periprosthetic tissue and/or synovial fluid were 69.5, 52.8, 54.8 and 60.2%, respectively. The specificities were 97.6, 90.3, 93.0 and 89.9%, respectively. Sonicate fluid culture of implants was more sensitive than peri-implant tissue, synovial fluid and combination of periprosthetic tissue and/or synovial fluid for all infection types, though it was especially useful in delayed infection: 91.3% vs. 60.0% (p?=?0.0015), 63.2% (p?=?0.0005) and 66.7% (p?=?0.0001), respectively. When sonicate fluid culture of implants was performed in addition to conventional cultures, the sensitivity increased significantly in total (from 60.2 to 77.1%) and delayed PJI (from 45.1 to 71.7%). On the other hand, for early PJI, sonicate fluid culture of prosthesis was not superior to conventional diagnostic methods.     

血小板计数可作为预测关节假体周围感染的新指标

背景:对于患者而言,以关节腔液检测关节假体周围感染是侵入性的并且是痛苦的。由于血小板计数是一种常规的血液检测措施,已被用作感染性疾病的预测指标,故推测其可能作为关节假体周围感染的指标之一。目的:评价血小板计数联合白细胞计数、红细胞沉降率、C-反应蛋白对诊断关节假体周围感染的准确性。方法:回顾性收集了2013年3月至2018年12月在广州中医药大学第一附属医院行关节置换翻修的患者。根据美国肌肉骨骼感染学会的标准,其中77例确诊为关节假体周围感染,其余137例为无菌性松动。收集并比较两组的血小板计数、白细胞计数、红细胞沉降率及C-反应蛋白水平,计算其诊断关节假体周围感染的敏感性、特异性、阳性预测值和阴性预测值。结果与结论:关节假体周围感染组中血小板计数明显升高,其对诊断关节假体周围感染的敏感性和特异性分别为64.94%和86.13%。血小板计数诊断关节假体周围感染的特异性高于红细胞沉降率和C-反应蛋白。因此认为血小板计数对诊断关节假体周围感染具有一定的参考价值。对于怀疑关节假体周围感染的患者,可通过检测血小板计数辅助诊断。     

Staphylococcal IgM enzyme-linked immunosorbent assay for diagnosis of periprosthetic joint infections

Delayed orthopedic joint prosthesis infections (DOJP-Is) due to staphylococci frequently result in prosthetic revision. Specific and noninvasive diagnostic tests are unavailable, and DOJP-Is are commonly diagnosed at advanced stages of disease. An enzyme-linked immunosorbent assay (ELISA) was developed to detect serum antibodies against staphylococcal slime polysaccharide antigens. Using a cutoff of 0.35 ELISA units, the test showed a specificity of 95.1% (95% confidence interval [CI], 85.4 to 98.7%) and a sensitivity of 89.7% (71.5 to 97.3%) on a sample of 90 individuals.     

Diagnosis of prosthetic joint infection by beadmill processing of a periprosthetic specimen

We report a microbiological process for the documentation of prosthetic joint infection (PJI). Intraoperative periprosthetic tissue samples from 92 consecutive patients undergoing revision surgery for PJI were submitted to mechanized beadmill processing: specimens were aseptically collected in polypropylene vials, filled with sterile water and glass beads and submitted to mechanized agitation with a beadmill. The documentation rate of PJI following culture on solid and liquid media was 83.7% and the contamination rate 8.7%. Final documentation was obtained after overnight culture for 51.9% of cases and with 7 days of broth culture for all documented cases.     

Experimental reproduction of periprosthetic joint infection: Developing a representative animal model

BackgroundInfection after arthroplasty (prosthetic joint infection; PJI) is a devastating complication that can lead to functional loss of the affected limb. The purpose of the present study is to develop an animal model of PJI using a three-dimensional printed species-specific implant, which is a step forward for future research to develop new therapeutic strategies.MethodsFifteen New Zealand White rabbits were employed to reproduce PJI by intra-articular inoculation of 10⁵ cfu/ml of Staphylococcus aureus ATCC® 29213. Three-dimensional printing technology was used to design a species-specific four-millimeter-thick implant maintaining the anatomical irregularities of the tibial-articular surface. Response to bacterial inoculation was monitored by clinical (weight and temperature), hematological (leukocyte, lymphocyte and platelet counts) and biochemical (erythrocyte sedimentation rate) analyses at the time of inoculation and seven days thereafter, when microbiological samples for culture were also taken.ResultsAll animals recovered from surgery and all displayed full weight-bearing four days postoperatively. Fourteen of the 15 tested animals (93.3%) presented positive microbiological cultures. A statistically significant increase was found in the number of platelets and leukocytes, as well as a significant decrease in the percentage of lymphocytes, with P = 0.0001 in all cases.ConclusionsAn experimental model faithfully reproducing the periprosthetic infection environment and achieving a high rate of infection has been designed. The use of three-dimensional printed species-specific implants allows rapid postoperative recovery of animals and the development of a stable biofilm. These characteristics make it an interesting model to study its pathogenesis and possible therapeutic strategies.     

全膝关节置换术后假体周围感染患者社会心理因素的探讨

目的探讨和分析全膝关节置换术后假体周围感染患者的社会心理因素的变化情况,以期为此类患者提供更好的社会心理康复治疗。方法采用调查问卷方法,运用心理状况自评量表(SCL-90)、艾森克个性问卷(EPQ)、社会支持评定量表(SSRS)及生活事件量表(LES)分别对21例全膝关节置换术后假体周围感染患者(研究组)和30例初次全膝关节置换患者(对照组)进行问卷调查,资料统计结果采用t检验及方差分析对各项指标均数进行检测分析。结果全膝关节置换术后假体周围感染组的患者表现出较多的社会心理因素障碍,其中心理状况自评表中的躯体化、抑郁、焦虑、精神性、阳性项数及总分6个因子评定均显著高于对照组(P0.05);艾森克个性问卷中的精神质与神经质显著低于对照组(P0.01);社会支持评定表中的客观支持、支持利用度及总社会支持评分均显著低于对照组(P0.01);生活事件量表中的紧张总值、负性事件紧张总值、生活事件数均显著高于对照组(P0.01)。结论全膝关节置换术后假体周围感染患者普通存在较明显的社会心理障碍,即心理健康和社会支持力均低下,对此类患者除在给予药物、手术治疗的同时,应给予适当的心理治疗与社会支持干预。     

保留抗生素骨水泥间隔物治疗假体周围感染的研究现状

随着人工关节置换手术总数的不断增长,术后假体周围感染(periprosthetic joint infection,PJI)的绝对数量也在增加.人工全膝关节置换(total knee arthroplasty,TKA)和人工全髋关节置换(total hip arthroplasty,THA)术后假体周围感染的治疗目前仍具有挑战性.在现有的几种治疗方案中,一期植入抗生素负载的骨水泥间隔物,二期再行假体植入被认为是治疗PJI的金标准[1].但因其治疗周期长,且需要行多次手术,使得相当一部分的患者在植入间隔物后未再行二期手术植入新的假体.随着间隔物制作技术的成熟,已经有越来越多的学者报道了保留抗生素骨水泥间隔物治疗P JI取得了较为满意的临床疗效.本文综述了抗生素骨水泥间隔物的材料特性、保留间隔物的临床应用现状,归纳总结了临床疗效,分析了目前其优势及缺点,并对未来的发展做了展望.     

Challenges in periprosthetic knee-joint infection

The number of knee arthroplasty procedures is growing and projected to further increase. The risk for periprosthetic joint infection (PJI) is estimated to be low (<1%). However, considering the increasing number of total knee arthroplasty, the increasing number of patients with multiple comorbidities, and the lifelong risk for acquiring hematogenous infection, the total number of PJI will further increase. Despite existing treatment concepts for PJI of the knee, there are still questions to solve, such as type of debridement surgery in case of implant retention, the role of a spacer from a microbiological perspective, and the optimal duration of antimicrobial therapy. In this REVIEW, these questions will be analyzed according to the available literature and the experience of the authors. Moreover, we REVIEW the most recent data on infection, risk factors, and microbiology of PJI.     

Nanopore 16S amplicon sequencing enables rapid detection of pathogen in knee periprosthetic joint infection

ObjectivesWe investigated whether nanopore 16S amplicon sequencing is capable of bacterial identification in patients with knee prosthetic joint infection (PJI), and we compared its efficacy with conventional culture studies.MethodsIn total, 36 patients who had clinical manifestation suspected of PJI were enrolled in this study. To begin, synovial fluids were aspirated from the affected knee using aseptic technique and tissues specimens were obtained during the surgery. Next, DNA was extracted from the synovial fluid or tissues, and 16S rDNA PCR was performed. In PCR positive cases, nanopore amplicon sequencing was then performed for up to 3 h. The results of amplicon sequencing were compared to those of conventional culture studies.ResultsOf the 36 patients enrolled, 22 were classified as true infections according to the MSIS criteria whereas 14 were considered uninfected. Among the 22 PJI cases, 19 cases were culture positive (CP-PJI) while three cases were culture negative (CN-PJI). In 14 of 19 (73.7 %) CP- PJI cases, 16S sequencing identified concordant bacteria with conventional culture studies with a significantly shorter turnaround time. In some cases, nanopore 16S sequencing was superior to culture studies in the species-level identification of pathogen and detection of polymicrobial infections. Altogether, in the majority of PJI candidate patients (32 of 36, 88.9 %), 16S sequencing achieved identical results to cultures studies with a significantly reduced turnaround time (100.9 ± 32.5 h vs. 10.8 ± 7.7 h, p < 0.001).ConclusionsNanopore 16S sequencing was found to be particularly useful for pathogen identification in knee PJI. Although the sensitivity was not superior to culture studies, the nanopore 16S sequencing was much faster, and species-level identification and detection of polymicrobial infections were superior to culture studies.     

基于网络药理学分析五味消毒饮治疗关节假体周围感染的作用机制

文题释义：网络药理学：是基于系统生物学和药代动力学的理论,对生物信息的网络分析,选取特定节点进行多靶点药物分子设计,以多靶点作用、多种信号途径综合分析为特点,旨在预测药物治疗疾病的潜在机制,提高临床研究成功率,减少研究经费的新兴学科。关节假体周围感染：是人工关节置换术后的一种极具破坏性的并发症,主要由金黄色葡萄球菌等致病菌引起假体周围发生化脓性感染及假体表面形成生物膜为主要特点,临床表现为术口及周围红、肿、热、痛,窦道形成,渗液流脓等。背景：五味消毒饮在临床中已被用于治疗关节假体周围感染,但因五味消毒饮所含有效成分复杂,其分子作用机制尚不明确。目的：探究五味消毒饮治疗关节假体周围感染的作用机制。方法：通过中药系统药理学成分分析数据库(BATMAN-TCM)预测获得五味消毒饮的有效化合物及靶点基因,利用GeneCards和OMIM数据库获得关节假体周围感染疾病的相关靶点基因,取两者交集后得到五味消毒饮-关节假体周围感染疾病交集基因。随后采用STRING在线数据库构建蛋白相互作用网络(PPI),根据度值筛选核心基因。将交集基因输入Cytoscape 3.7.2软件以构建WWXDY-靶点-关节假体周围感染可视化网络图,并借助DAVID在线工具进行交集靶点的基因本体论(GO)功能和京都基因与基因组百科全书(KEGG)通路富集分析,探讨其抗关节假体周围感染的作用机制。结果与结论：①从BATMAN-TCM平台共预测出五味消毒饮的有效化合物37个,作用靶点共914个;从GeneCards和OMIM数据库筛选出关节假体周围感染疾病的相关靶点基因286个;取交集获得药物与疾病交集靶点39个,经筛选得到核心基因16个;②GO分析结果显示,交集靶基因的生物过程主要是趋化因子生物合成过程的正向调控、蛋白激酶B信号、炎症反应、脂多糖媒介的信号通路、细胞因子分泌的负调控参与免疫应答等;分子功能为细胞因子活性、生长因子活性、ICAM-3受体活性、Ⅲ型转化生长因子受体结合、前列腺素-内过氧化物合酶活性;细胞组分为细胞外空间、细胞表面、细胞膜外侧面、胞外区、整合蛋白αL-β2复合体;③KEGG通路富集结果主要涉及类风湿性关节炎、疟疾、细胞因子-细胞因子受体相互作用、南美锥虫病、利什曼病、炎症性肠病、阿米巴病、肿瘤坏死因子信号通路、肺结核、自然杀伤细胞介导的细胞毒性等信号通路;④提示五味消毒饮治疗关节假体周围感染疾病的作用机制呈多个有效化合物、多个作用途径以及多个靶点基因的特点,为后续实验提供了新思路、新方向。ORCID: 0000-0001-5949-6483(张海涛)中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

Success rates,characteristics, and costs of articulating antibiotic spacers for total knee periprosthetic joint infection

Background

The optimal type, characteristics, and success rates of articulating antibiotic spacers used during total knee arthroplasty (TKA) periprosthetic joint infection (PJI) have not been well defined in a single series. We sought to (1) determine the success rate for three unique spacer constructs and (2) evaluate any microbiological, surgical, or patient characteristics that would influence the success rate.