Diagnosis of knee prosthetic joint infection; aspiration and biopsy

BackgroundProsthetic joint infection (PJI) is a significant cause of morbidity and mortality following knee replacement surgery. The diagnosis can be challenging and is based on a combination of clinical suspicion, radiographic findings and also biochemical/ microbiological investigations. Our Aim was to review the role of aspiration and biopsy in the diagnosis of PJI in Total Knee Arthroplasty (TKA).Method/resultsAspirated synovial fluid should be analysed by direct culture, via blood culture bottles, EDTA bottles for cell count and ‘point of care’ testing such as leucocyte esterase or alpha defensin. Synovial WCC and PMN cell percentage are important steps in diagnosis of both acute and chronic PJI. A minimum of 5 deep samples using a 5 clean instrument technique should be obtained and sent for tissue culture done either blind or arthroscopic. Formal fluoroscopic guided interface biopsy has also been described with excellent results. In a recent series of 86 TKRs preoperative arthroscopic biopsy group had a sensitivity of 100%, specificity of 94.7%, positive predictive value of 87.4% and a negative predictive value of 100%.ConclusionIn the presence of clinical suspicion with raised biomarkers, it is recommended that aspiration +/- biopsy with synovial fluid testing is performed. Direct culture and cell count are recommended. ‘Point of care tests’ such as Leucocyte Esterase testing should be considered. Duration of culture, including pathogen and host factors, should be discussed with a local microbiology/ID department in the context of a formal multi-disciplinary team.     

Avoidance of intramedullary violation in computer-assisted total knee arthroplasty lowers the incidence of periprosthetic joint infection compared with conventional total knee arthroplasty: A propensity score matching analysis of 5342 cases

BackgroundConventional total knee arthroplasty (CONV-TKA) inevitably perturbs femoral medullary canal, disturbs medullary micro-architecture and increases blood loss and inflammatory responses. We hypothesized that avoidance of intramedullary violation may lower the incidence of periprosthetic joint infection (PJI). The aim of this study was to verify whether computer-assisted total knee arthroplasty (CAS-TKA) lowers the incidence of PJI as compared with CONV-TKA.MethodsA propensity score matching study of 5342 patients who underwent CAS-TKA (n = 1085) or CONV-TKA (n = 4257) for primary osteoarthritis of the knee from 2007 to 2015 in our institute was performed. Patients who underwent CAS-TKA were matched to those who received CONV-TKA at a 1:2 ratio according to demographics and comorbidities. PJI was defined according to the Musculoskeletal Infection Society diagnostic criteria from the 2013 International Consensus Meeting.ResultsAfter controlling potential risk factors, the use of CAS-TKA resulted in a lower incidence of PJI as compared with CONV-TKA [adjusted hazard ratio (HR), 0.42; 95% confidence interval (CI), 0.18–0.99]. The same trend in PJI reduction was observed with the usage of CAS-TKA under sensitivity testing [HR, 0.33; 95% CI, 0.12–0.95]. The cumulative incidence of PJI was lower in the CAS-TKA group than the CONV-TKA group (log-rank test, p = 0.013).ConclusionAvoidance of intramedullary violation during TKA may play a pivotal role in lowering the incidence of PJI. The use of CAS-TKA can reduce the incidence of PJI, with a better survival rate in terms of being free of PJI, as compared with CONV-TKA.Level of evidence III.     

Prosthetic joint infection due to Lysobacter thermophilus diagnosed by 16S rRNA gene sequencing

We report the first case of prosthetic joint infection caused by Lysobacter thermophilus which was identified by 16S rRNA gene sequencing. Removal of prosthesis followed by antibiotic treatment resulted in good clinical outcome. This case illustrates the use of molecular diagnostics to detect uncommon organisms in suspected prosthetic infections.     

膝关节置换与关节镜治疗膝关节色素沉着绒毛结节性滑膜炎

背景：外科治疗色素沉着绒毛结节性滑膜炎能够最大程度的切除病变滑膜,最大限度的恢复关节功能。目的：探讨人工全膝关节置换与关节镜下滑膜切除治疗膝关节色素沉着绒毛结节性滑膜炎的膝关节功能和复发率。方法：回顾性分析中南大学湘雅医院骨科2006年12月至2011年12月收治的34例膝关节色素沉着绒毛结节性滑膜炎行手术治疗患者,治疗后病检均为弥漫性色素沉着绒毛结节性滑膜炎,其中24例患者行膝关节镜下滑膜切除,10例色素沉着绒毛结节性滑膜炎患者行人工全膝关节置换,治疗后根据病情行辅助放疗。膝关节镜下滑膜切除组采用Lysholm功能评分,人工全膝关节置换组采用美国膝关节协会评分,比较两组患者治疗前后膝关节功能,随访观察比较两组间的膝关节功能恢复情况及复发率。结果与结论：34例膝关节色素沉着绒毛结节性滑膜炎患者均获有效随访,随访时间12-66个月,平均41.3个月。统计学分析结果表明关节镜下滑膜切除组治疗后膝关节Lysholm功能评分为(86.3±10.3)分,明显高于治疗前的(55.5±13.2)分(t=3.81,P =0.016,P < 0.05)。人工全膝关节置换组美国膝关节协会评分由治疗前的(40.7±2.2)分提高到(90.2±1.1)分(t =6.27,P < 0.01);关节镜下滑膜切除组美国膝关节协会评分由治疗前的(34.2±3.9)分提高到(80.8±1.9)分 (t =16.58,P < 0.01)。证实,关节镜下滑膜切除结合辅助放疗治疗膝关节色素沉着绒毛结节性滑膜炎可取得较好效果,人工全膝关节置换治疗晚期膝关节弥漫型色素沉着绒毛结节性滑膜炎可较好恢复膝关节功能,且复发率较低。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;组织工程全文链接：     

Two-stage knee arthrodesis with a modular intramedullary nail due to septic failure of revision total knee arthroplasty with extensor mechanism deficiency

Background

Periprosthetic joint infection is a serious complication and reconstruction after failed revision total knee arthroplasty with significant bone loss and compromised soft-tissues can be challenging. Objective of this study was to assess clinical and functional results, implant survival and infection recurrence rates in patients treated with two-stage arthrodesis after failed revision TKA with extensor mechanism deficiencies due to PJI, and to identify the factors that affect outcomes after surgery.

Does intraarticular steroid infiltration increase the rate of infection in subsequent total knee replacements?

Steroid injection into the arthritic joint is a well-known treatment. Its efficacy is well documented. An increase in the incidence of infection secondary to steroid injection has been reported in recent literature. Based on the current literature we carried out a retrospective study to evaluate the incidence of infection in primary total knee arthroplasty as a result of previous steroid infiltration into the knee joint.In our study, 440 patients underwent total knee replacement between 1997 and 2005. Only 90 patients had intraarticular steroid injection prior to surgery, of which 45 patients had injection within 1 year prior to surgery. A matched cohort of 180 patients who had total knee replacement without steroid injection was used as control group to compare the infection rate. All patients had at least 1 year follow up. Two cases of superficial infection were noted in the study group and five cases of superficial infection in the control group. No cases of deep infection were noted in either group. Statistical analysis showed no significant difference in incidence of infection in either group (P value 1.0).This study showed no increase in the incidence of infection in patients with total knee arthroplasty with prior steroid injection.     

Revision total knee arthroplasty outcomes in solid organ transplant Patients,a matched cohort study of aseptic and infected revisions

BackgroundPrevious studies have demonstrated that solid organ transplant (SOT) patients undergoing primary total knee arthroplasty (TKA) are at an increased risk of postoperative complications. The purpose of this study is to utilize a large, national database to investigate revision TKA (rTKA) outcomes in SOT patients.MethodsThis was a retrospective review utilizing the Nationwide Readmissions Database (NRD) and ICD-9 codes to identify patients who underwent rTKA from 2010-2014 with a history of at least one SOT. Propensity-score-matching (PSM) was used to compare rTKA outcomes in SOT patients compared to matched patients without SOT.ResultsA total of 303,867 rTKAs, with 464 of those being performed in SOT patients, were included in the study. Of these, 71,903 and 182 were performed for PJI in non-SOT and SOT patients, respectively. rTKA was performed most frequently in kidney transplant patients (53.0%) followed by liver transplant patients (34.3%). For non-PJI patients, SOT patients had a higher 90-day readmission rate than matched non-SOT rTKA patients (23.2% vs 12.6%, p = 0.006). However, there were no differences in 90-day readmission rates for specific rTKA complications, subsequent revision rTKA, or mortality. Among patients undergoing rTKA for PJI, there was no difference in overall 90-day readmission rate, readmission for specific rTKA complications, subsequent revision rTKA, or mortality.ConclusionsWhile the increased medical comorbidities associated with SOT place patients at increased risk for complications following rTKA, it appears that SOT alone does not do so when patients are matched based on overall medical comorbidity.     

No associations between self-reported knee joint instability and radiographic features in knee osteoarthritis patients prior to Total Knee Arthroplasty: A cross-sectional analysis of the Longitudinal Leiden Orthopaedics Outcomes of Osteo-Arthritis study (LOAS) data

Background

To describe the prevalence of self-reported knee joint instability in patients with pre-surgery knee osteoarthritis (OA) and to explore the associations between self-reported knee joint instability and radiological features.

Unicompartmental knee arthroplasty is associated with lower proportions of surgical site infection compared with total knee arthroplasty: A retrospective nationwide database study

BackgroundThis study aimed to clarify the association between types of knee arthroplasty (KA) (total knee arthroplasty (TKA) or unicompatmental knee arthroplasty (UKA)) and surgical site infection (SSI) with adjustment for various factors, using a Japanese national database.MethodsData on 181,608 patients who underwent unilateral primary KA for osteoarthritis from 2010 to 2017 were obtained from the Japanese Diagnosis Procedure Combination database. SSI was identified based on International Classification of Diseases 10th Revision codes. Deep SSI (i.e. periprosthetic joint infection (PJI)) was identified as SSI treated with surgical procedures. Multivariable logistic regression analyses for SSI and PJI were performed, in which dependent variables included types of KA, patient backgrounds (sex, age, body mass index (BMI), smoking status, comorbidities), and seasonality.ResultsEight percent of analyzed patients underwent UKA, while 92% underwent TKA. The proportions of SSI and PJI after UKA were 0.9% and 0.3%, respectively, both of which were lower than those after TKA (1.9% and 0.6%) (P < 0.001). Multivariable analyses showed lower proportions of SSI for UKA (adjusted odds ratio, 0.47; 95% confidence interval, 0.37–0.60; P < 0.001) and PJI (adjusted odds ratio, 0.47; 95% confidence interval, 0.34–0.65; P < 0.001) than TKA. Other factors associated with both SSI and PJI included male sex, BMI >30 kg/m², renal dysfunction and summer season.ConclusionUKA was associated with lower proportions of SSI and PJI than TKA. Surgeons should carefully consider the indication of UKA before performing TKA, especially in patients with knee unicompartmental osteoarthritis who are at a high risk for SSI or PJI.     

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.     

新型国产膝关节假体用于全膝关节置换术的临床研究

目的 通过随机对照临床试验,验证新型国产膝关节假体临床应用的安全性和有效性.方法 本研究采用多中心、随机、单盲、阳性平行对照设计,自2017年3月至2019年3月在全国6家医院共招募72例受试者,试验组和对照组各36例.试验组使用新型国产膝关节假体,对照组使用成熟的膝关节假体.所有受试者在术前和术后3个月、6个月、1年...     

单髁置换术与全膝关节置换术在治疗膝内侧单间室骨性关节炎术后早期关节遗忘度中的比较

目的 比较膝关节单髁置换术（unicompartmental knee arthroplasty, UKA）与全膝人工关节置换术（total knee arthroplasty, TKA）治疗膝内侧单间室骨性关节炎的早期膝关节功能评分与关节遗忘度评分,评价并分析两类术式在早期关节遗忘度评分方面的差异。方法 回顾性分析上海中医药大学附属光华医院关节外科2016年10月至2020年10月期间行全膝关节置换术及膝关节单髁置换术患者共296例,根据不同手术方式进行分组,其中TKA组共144例,UKA组共152例。出院后对患者术后1、3、6、12、24个月进行门诊复查,进行关节遗忘度评分、膝关节功能HSS评分、目测类比评分（VAS评分）。结果 (1)296例患者获得24～37个月的随访,平均随访（30.41±6.93）个月;(2)术后24个月TKA组与UKA组的HSS评分与VAS评分均明显好于术前,组内比较差异具有统计学意义（P<0.05）;(3)两组患者术后24个月膝关节VAS评分的改善程度差异无统计学意义（P>0.05）,UKA组的HSS评分改善程度好于TKA组,且差异有统计学意...     

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.     

The effect of preoperative oral antibiotic use on the risk of periprosthetic joint infection after primary knee or hip replacement: a retrospective study with a 1-year follow-up

ObjectivesAntibiotics are used for various reasons before elective joint replacement surgery. The aim of this study was to investigate patients' use of oral antibiotics before joint replacement surgery and how this affects the risk for periprosthetic joint infection (PJI).MethodsPatients having a primary hip or knee replacement in a tertiary care hospital between September 2002 and December 2013 were identified (n = 23 171). Information on oral antibiotic courses purchased 90 days preoperatively and patients' chronic diseases was gathered. Patients with a PJI in a 1-year follow-up period were identified. The association between antibiotic use and PJI was examined using a multivariable logistic regression model and propensity score matching.ResultsOne hundred and fifty-eight (0.68%) cases of PJI were identified. In total, 4106 (18%) joint replacement operations were preceded by at least one course of antibiotics. The incidence of PJI for patients with preoperative use of oral antibiotics was 0.29% (12/4106), whereas for patients without antibiotic use it was 0.77% (146/19 065). A preoperative antibiotic course was associated with a reduced risk for subsequent PJI in the multivariable model (OR 0.40, 95% CI 0.22–0.73). Similar results were found in the propensity score matched material (OR 0.34, 95% CI 0.18–0.65).ConclusionsThe use of oral antibiotics before elective joint replacement surgery is common and has a potential effect on the subsequent risk for PJI. Nevertheless, indiscriminate use of antibiotics before elective joint replacement surgery cannot be recommended, even though treatment of active infections remains an important way to prevent surgical site infections.     

关节镜下半月板切除术与半月板成形术治疗膝关节半月板损伤的效果及对膝关节功能的影响

目的:探究关节镜下半月板切除术与半月板成形术治疗膝关节半月板损伤的效果及对膝关节功能的影响.方法:回顾性分析本院2017年7月至2019年12月收治的90例膝关节半月板损伤患者的临床资料,按照手术方式分为研究组(n=41)与对照组(n=49),两组患者均采用关节镜进行诊治,其中研究组患者所用术式为半月板成形术,而对照组...     

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.

Efficacy of antifungal-impregnated cement spacer against chronic fungal periprosthetic joint infections after total knee arthroplasty

Background

Although two-stage exchange arthroplasty is considered a treatment of choice for chronic features of fungal PJI (periprosthetic joint infection), there is no consensus for local use of antifungal agent. The purpose of this study was to evaluate the efficacy of antifungal-impregnated cement spacer (AICS).

The impact of preoperative bacteriuria on the risk of periprosthetic joint infection after primary knee or hip replacement: a retrospective study with a 1-year follow up

ObjectivesPatients who undergo elective joint replacement are traditionally screened and treated for preoperative bacteriuria to prevent periprosthetic joint infection (PJI). More recently, this practice has been questioned. The purpose of this study was to determine whether preoperative bacteriuria is associated with an increased risk of PJI.MethodsPatients who had undergone a primary hip or knee replacement in a tertiary care hospital between September 2002 and December 2013 were identified from the hospital database (23 171 joint replacements, 10 200 hips, and 12 971 knees). The results of urine cultures taken within 90 days before the operation were obtained. Patients with subsequent PJI or superficial wound infection in a 1-year follow-up period were identified based on prospective infection surveillance. The association between bacteriuria and PJI was examined using a multivariable logistic regression model that included information on the operated joint, age, gender and the patients' chronic diseases.ResultsThe incidence of PJI was 0.68% (n = 158). Preoperative bacteriuria was not associated with an increased risk of PJI either in the univariate (0.51% versus 0.71%, OR 0.72, 95% CI 0.34–1.54) or in the multivariable (OR 0.82, 95% CI 0.38–1.77) analysis. There were no cases where PJI was caused by a pathogen identified in the preoperative urine culture. Results were similar for superficial infections.ConclusionsThere was no association between preoperative bacteriuria and postoperative surgical site infection. Based on these results, it seems that the preoperative screening and treatment of asymptomatic bacteriuria is not required.     

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.     

What is the patient experience following revision knee replacement: A systematic review and meta-analysis of the medium term patient reported outcomes

AimsRevision knee replacement is an increasingly common procedure, however, information on patient-focused outcomes is limited. This systematic review and meta-analysis aimed to investigate the medium-term patient reported outcomes following a revision knee replacement.MethodsWe performed a systematic review of MEDLINE and EMBASE (from inception to 1st March 2021) for articles reporting five year or greater patient reported outcome measures (PROMs) following revision knee replacement. A meta-analysis of PROMs data was undertaken using the Standardised Mean Difference (SMD). Quality of methodology was assessed using Wylde’s non-summative four-point system. The study was registered with PROPSERO (CRD42021199289).ResultsA total of 23 studies met the inclusion criteria containing 2414 patients at a mean minimum follow-up of 74 months (60–122). The reporting of PROMs were poorly standardised with several PROMs being used. The most commonly reported patient reported outcome was the Knee Society Score reported in 65% of studies (15/23). A meta-analysis of 629 eligible patients undergoing revision knee replacement revealed a significant improvement in pre-operative state with a SMD 2·05 95% CI 0.87, 3.23.ConclusionThis systematic review has found a significant and sustained improvement in patient-reported outcomes following a revision knee arthroplasty beyond five years. We found a variation in the usage and administration of PROMs which hinders a clear synthesis of results. Furthermore, the PROMs have not been robustly tested for validity in the context of a revision knee replacement.