Variation in Prosthetic Joint Infection and treatment strategies during 4.5 years of follow-up after primary joint arthroplasty using administrative data of 41397 patients across Australian, European and United States hospitals

Efficacy of a Novel Intraoperative Surgical Irrigant in Preventing Periprosthetic Joint Infections in Primary Knee, Hip, and Shoulder Arthroplasties: A Retrospective Analysis

OBJECTIVE

Primary joint arthroplasty (JA) is one of the most common operating room (OR) procedures, with knee and hip arthroplasties being listed in the top five most frequent OR procedures and while not as common, shoulder arthroplasties are increasing at greater rates than knee and hip arthroplasties. Periprosthetic joint/shoulder infections (PJI/PSI) are a devastating complication of primary JAs with infection prevention deemed as the single most important strategy in combating them. The objective of this study was to retrospectively evaluate the efficacy of XPERIENCE® Advanced Surgical Irrigation (XP) in preventing PJI following primary joint arthroplasty.

METHODS

This is a retrospective study of primary knee, hip and shoulder arthroplasties that were performed by multiple orthopedic surgeons at a single hospital setting. XPERIENCE was used as an intraoperative surgical irrigant either solely, or with other intraoperative practices for prevention of infection. Incidence of acute PJI occurring within 90 days of index surgery were retrospectively collated.

RESULTS

Four hundred and twenty-three (423) primary joint replacement surgeries treated intraoperatively with XP, were evaluated for acute PJI incidence. Retrospective evaluations determined that 95% of the subjects had at least one risk factor predisposing them to PJI. There were zero PJIs diagnosed in the knee and hip arthroplasty cohorts and zero PSIs diagnosed in the shoulder arthroplasty cohorts.

CONCLUSION

The absence of PJI/PSI diagnoses in the JA cohorts treated intraoperatively with XP indicates that it could be an efficacious antimicrobial irrigant in preventing PJI, and warrants being evaluated in prospective, randomized controlled clinical trials as the sole intraoperative irrigant, as well as in combination with the other intraoperative infection prevention regimens evaluated in this retrospective study.

Orthopedic Articular and Periarticular Joint Infections

Acute nontraumatic joint pain has an extensive differential. Emergency physicians must be adept at identifying limb and potentially life-threatening infection. Chief among these is septic arthritis. In addition to knowing how these joint infections typically present, clinicians need to be aware of host and pathogen factors that can lead to more insidious presentations and how these factors impact the interpretation of diagnostic tests.

The influence of gut microbiome on periprosthetic joint infections: State-of-the art

Early periprosthetic joint infection constitutes one of the most frightening complications of joint replacement. Recently, some evidence has highlighted the potential link between dysregulation of the gut microbiota and degenerative diseases of joints. It has been hypothesized that microbiome dysbiosis may increase the risk of periprosthetic joint infection by facilitating bacterial translocation from these sites to the bloodstream or by impairing local or systemic immune responses. Although the processes tying the gut microbiome to infection susceptibility are still unknown, new research suggests that the presurgical gut microbiota-a previously unconsidered component-may influence the patient's ability to resist infection. Exploring the potential impact of the microbiome on periprosthetic joint infections may therefore bring new insights into the pathogenesis and therapy of these disorders. For a successful therapy, a proper surgical procedure in conjunction with an antibacterial concept is essential. As per the surgical approach, different treatment strategies include surgical irrigation, debridement, antibiotic therapy, and implant retention with or without polyethylene exchange. Other alternatives could be one-stage or two-stage revisions surgery. Interventions that either directly target gut microbes as well as interventions that modify the composition and/or function of the commensal microbes represent an innovative and potentially successful field to be explored. In recent times, innovative therapeutic methods have arisen in the realm of microbiome restoration and the management of gut-related ailments. These progressive approaches offer fresh perspectives on tackling intricate microbial imbalances in the gastrointestinal tract. These emerging therapies signify a shift towards more precise and individualized approaches to microbiome restoration and the management of gut-related disorders. Once a more advanced knowledge of the pathways linking the gut microbiota to musculoskeletal tissues is gained, relevant microbiome-based therapies can be developed. If dysbiosis is proven to be a significant contributor, developing treatments for dysbiosis may represent a new frontier in the prevention of periprosthetic joint infections.

Clinical outcomes of non-COVID-19 orthopaedic patients admitted during the COVID-19 pandemic: a multi-centre interrupted time series analysis across hospitals in six different countries

OBJECTIVES

To assess across seven hospitals from six different countries the extent to which the COVID-19 pandemic affected the volumes of orthopaedic hospital admissions and patient outcomes for non-COVID-19 patients admitted for orthopaedic care.

DESIGN

A multi-centre interrupted time series (ITS) analysis.

SETTING

Seven hospitals from six countries who collaborated within the Global Health Data@Work collaborative.

PARTICIPANTS

Non-COVID-19 patients admitted for orthopaedic care during the pre-pandemic (January/2018-February/2020) and COVID-19 pandemic (March/2020-June/2021) period. Admissions were categorised as: (1) acute admissions (lower limb fractures/neck of femur fractures/pathological fractures/joint dislocations/upper limb fractures); (2) subacute admissions (bone cancer); (3) elective admissions (osteoarthritis).

OUTCOME MEASURES

Monthly observed versus expected ratios (O/E) were calculated for in-hospital mortality, long (upper-decile) length-of-stay and hospital readmissions, with expected rates calculated based on case-mix. An ITS design was used to estimate the change in level and/or trend of the monthly O/E ratio by comparing the COVID-19 pandemic with the pre-pandemic period.

RESULTS

69 221 (pre-pandemic) and 22 940 (COVID-19 pandemic) non-COVID-19 orthopaedic patient admissions were included. Admission volumes were reduced during the COVID-19 pandemic for all admission categories (range: 33%-45%), with more complex patients treated as shown by higher percentages of patients admitted with ≥1 comorbidity (53.8% versus 49.8%, p<0.001). The COVID-19 pandemic was not associated with significant changes in patient outcomes for most diagnostic groups. Only for patients diagnosed with pathological fractures (pre-pandemic n=1671 and pandemic n=749), the COVID-19 pandemic was significantly associated with an immediate mortality reduction (level change of -77.7%, 95% CI -127.9% to -25.7%) and for lower limb fracture patients (pre-pandemic n=9898 and pandemic n=3307) with a significantly reduced trend in readmissions (trend change of -6.3% per month, 95% CI -11.0% to -1.6%).

CONCLUSIONS

Acute, subacute, as well as elective orthopaedic hospital admissions volumes were reduced in all global participating hospitals during the COVID-19 pandemic, while overall patient outcomes for most admitted non-COVID-19 patients remained the same despite the strain caused by the surge of COVID-19 patients.

The relationship between publication of high-quality evidence and changes in the volume and trend of subacromial decompression surgery for patients with subacromial pain syndrome in hospitals across Australia, Europe and the United States: a controlled interrupted time series analysis

AIMS

To evaluate the extent to which publication of high-quality randomised controlled trials(RCTs) in 2018 was associated with a change in volume or trend of subacromial decompression(SAD) surgery in patients with subacromial pain syndrome(SAPS) treated in hospitals across various countries.

METHODS

Routinely collected administrative data of the Global Health Data@work collaborative were used to identify SAPS patients who underwent SAD surgery in six hospitals from five countries (Australia, Belgium, Netherlands, United Kingdom, United States) between 01/2016 and 02/2020. Following a controlled interrupted time series design, segmented Poisson regression was used to compare trends in monthly SAD surgeries before(01/2016-01/2018) and after(02/2018-02/2020) publication of the RCTs. The control group consisted of musculoskeletal patients undergoing other procedures.

RESULTS

A total of 3.046 SAD surgeries were performed among SAPS patients treated in five hospitals; one hospital did not perform any SAD surgeries. Overall, publication of trial results was associated with a significant reduction in the trend to use SAD surgery of 2% per month (Incidence rate ratio (IRR) 0.984[0.971-0.998]; P = 0.021), but with large variation between hospitals. No changes in the control group were observed. However, publication of trial results was also associated with a 2% monthly increased trend (IRR 1.019[1.004-1.034]; P = 0.014) towards other procedures performed in SAPS patients.

CONCLUSION

Publication of RCT results was associated with a significantly decreased trend in SAD surgery for SAPS patients, although large variation between participating hospitals existed and a possible shift in coding practices cannot be ruled out. This highlights the complexities of implementing recommendations to change routine clinical practice even if based on high-quality evidence.

Diagnostic accuracy of sonication fluid cultures from prosthetic components in periprosthetic joint infection: an updated diagnostic meta-analysis

BACKGROUND

Periprosthetic joint infection (PJI) is the most serious complication following total joint arthroplasty (TJA) and has a significant impact on patients and the national healthcare system. To date, the diagnosis of PJI is still confronted with dilemmas. The present study investigated the validity of sonication fluid culture (SFC) for removing implants in the diagnosis of PJI after joint replacement.

METHODS

From database establishment to December 2020, relevant literature was retrieved from the PubMed, Web of Science, Embase and Cochrane Library databases. Two reviewers independently performed quality assessment and data extraction to calculate the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), area under the curve (AUC) and diagnostic odds ratio (DOR) to evaluate the diagnostic value of overall SFC for PJI.

RESULTS

A total of 38 eligible studies including 6302 patients were selected in this study. The pooled sensitivity, specificity, PLR, NLR, and DOR of SFC for PJI diagnosis were 0.77 (95% confidence interval [CI], 0.76-0.79), 0.96 (95% CI, 0.95-0.96), 18.68 (95% CI, 11.92-29.28), 0.24 (95% CI, 0.21-0.29), and 85.65 (95% CI, 56.46-129.94), respectively, while the AUC was 0.92.

CONCLUSION

This meta-analysis showed that SFC was of great value in PJI diagnosis, and the evidence of SFC on PJI was more favorable but not yet strong. Therefore, improvement of the diagnostic accuracy of SFC is still necessary, and the diagnosis of PJI continues to warrant a multiplex approach before and during a revision procedure.

Dithiotreitol pre-treatment of synovial fluid samples improves microbiological counts in peri-prosthetic joint infection

PURPOSE

Synovial fluid cultures of periprosthetic joint infections (PJI) may be limited by bacteria living in the fluids as biofilm-aggregates. The antibiofilm pre-treatment of synovial fluids with dithiotreitol (DTT) could improve bacterial counts and microbiological early stage diagnosis in patients with suspected PJI.

METHODS

Synovial fluids collected from 57 subjects, affected by painful total hip or knee replacement, were divided into two aliquots, one pre-treated with DTT and one with normal saline. All samples were plated for microbial counts. Sensitivity of cultural examination and bacterial counts of pre-treated and control samples were then calculated and statistically compared.

RESULTS

Dithiothreitol pre-treatment led to a higher number of positive samples, compared to controls (27 vs 19), leading to a statistically significant increase in the sensitivity of the microbiological count examination from 54.3 to 77.1% and in colony-forming units count from 1884 ± 2.129 CFU/mL with saline pre-treatment to 20.442 ± 19.270 with DTT pre-treatment (P = 0.02).

CONCLUSIONS

To our knowledge, this is the first report showing the ability of a chemical antibiofilm pre-treatment to increase the sensitivity of microbiological examination in the synovial fluid of patients with peri-prosthetic joint infection. If confirmed by larger studies, this finding may have a significant impact on routine microbiological procedures applied to synovial fluids and brings further support to the key role of bacteria living in biofilm-formed aggregates in joint infections.

The Impact of a Dedicated Multidisciplinary Team Approach for Prosthetic Joint Infections of the Lower Limb

Introduction

Prosthetic joint infections (PJI) of the hip and knee have significant morbidity and mortality, and present with varying local, host and microbiological factors. Given the broad presentation and complexity of PJI’s, we developed a dedicated multidisciplinary team (MDT) to manage this complex patient cohort, and report on our early outcomes.

Methods

This was a retrospective observational study of all patients diagnosed with a prosthetic joint infection of the hip or knee (n = 71) at our institution during a 4.5-year period. Patients treated after development of the MDT (post-MDT) (n = 44), were compared to a control group prior establishment of the MDT (pre-MDT) (n = 27).

Results

85.2% of individuals in the pre-MDT, and 85.7% of individuals in the post-MDT group were considered cured at a minimum 2 years post-operatively according to the Delphi-based definition. The total number of admissions to hospital (2.44 vs. 1.84) and total number of antibiotics used (3.37 vs. 2.75) decreased in the post-MDT group; however, differences were not considered statistically significant.

Discussion

Implementation of a dedicated MDT in the management of individuals with PJI’s of the lower limb at our hospital has allowed early and effective collaboration between healthcare personnel, with early promising results. Given the broad nature of PJI, future studies are ongoing to determine modifiable risk factors to reduce the incidence and improve outcomes of individuals with PJI’s where systems can then be implemented into already established MDTs to achieve the best clinical outcome for our patients.

Biomimetic AgNPs@antimicrobial peptide/silk fibroin coating for infection-trigger antibacterial capability and enhanced osseointegration

Endowing implant surfaces with combined antibacterial and osteogenic properties by drug-loaded coatings has made great strides, but how to achieve the combined excellence of infection-triggered bactericidal and in vivo-proven osteogenic activities without causing bacterial resistance still remains a formidable challenge. Herein, antimicrobial peptides (AMPs) with osteogenic fragments were designed and complexed on the surface of silver nanoparticle (AgNP) through hydrogen bonding, and the collagen structure-bionic silk fibroin (SF) was applied to carry AgNPs@ AMPs to achieve infection-triggered antibacterial and osteointegration. As verified by TEM, AMPs contributed to the dispersion and size-regulation of AgNPs, with a particle size of about 20 nm, and a clear protein corona structure was observed on the particle surface. The release curve of silver ion displayed that the SF-based coating owned sensitive pH-responsive properties. In the antibacterial test against S.aureus for up to 21 days, the antibacterial rate had always remained above 99%. Meanwhile, the underlying mechanism was revealed, originating from the destruction of the bacterial cell membranes and ROS generation. The SF-based coating was conducive to the adhesion, diffusion, and proliferation of bone marrow stem cells (BMSCs) on the surface, and promoted the expression of osteogenic genes and collagen secretion. The in vivo implantation results showed that compared with the untreated Ti implants, SF-based coating enhanced osseointegration at week 4 and 8. Overall, the AgNPs@AMPs-loaded SF-based coating presented the ability to synergistically inhibit bacteria and promote osseointegration, possessing tremendous potential application prospects in bone defects and related-infection treatments.

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AMPs and AgNPs were complexed through hydrogen bonds to form a protein crowns structure.

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Silk fibroin matrix was able to maintain the activity of AMPs over 21 d and endow with the infection-trigger release.

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The functional coating achieved synergistic antibacterial properties by damaging membrane structure and generating ROS.

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The coating displayed acceptable osteogenic properties in vitro and observably promoted osteointegration in vivo.

Estimating incidence rates of periprosthetic joint infection after hip and knee arthroplasty for osteoarthritis using linked registry and administrative health data

AIMS

The aim of this study was to estimate the 90-day periprosthetic joint infection (PJI) rates following total knee arthroplasty (TKA) and total hip arthroplasty (THA) for osteoarthritis (OA).

METHODS

This was a data linkage study using the New South Wales (NSW) Admitted Patient Data Collection (APDC) and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), which collect data from all public and private hospitals in NSW, Australia. Patients who underwent a TKA or THA for OA between 1 January 2002 and 31 December 2017 were included. The main outcome measures were 90-day incidence rates of hospital readmission for: revision arthroplasty for PJI as recorded in the AOANJRR; conservative definition of PJI, defined by T84.5, the PJI diagnosis code in the APDC; and extended definition of PJI, defined by the presence of either T84.5, or combinations of diagnosis and procedure code groups derived from recursive binary partitioning in the APDC.

RESULTS

The mean 90-day revision rate for infection was 0.1% (0.1% to 0.2%) for TKA and 0.3% (0.1% to 0.5%) for THA. The mean 90-day PJI rates defined by T84.5 were 1.3% (1.1% to 1.7%) for TKA and 1.1% (0.8% to 1.3%) for THA. The mean 90-day PJI rates using the extended definition were 1.9% (1.5% to 2.2%) and 1.5% (1.3% to 1.7%) following TKA and THA, respectively.

CONCLUSION

When reporting the revision arthroplasty for infection, the AOANJRR substantially underestimates the rate of PJI at 90 days. Using combinations of infection codes and PJI-related surgical procedure codes in linked hospital administrative databases could be an alternative way to monitor PJI rates.Cite this article: Bone Joint J 2022;104-B(9):1060-1066.

The accuracy of reporting of periprosthetic joint infection to the Australian Orthopaedic Association National Joint Replacement Registry

Aims

National joint registries under-report revisions for periprosthetic joint infection (PJI). We aimed to validate PJI reporting to the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR) and the factors associated with its accuracy. We then applied these data to refine estimates of the total national burden of PJI.

Methods

A total of 561 Australian cases of confirmed PJI were captured by a large, prospective observational study, and matched to data available for the same patients through the AOANJRR.

Results

In all, 501 (89.3%) cases of PJI recruited to the prospective observational study were successfully matched with the AOANJRR database. Of these, 376 (75.0%) were captured by the registry, while 125 (25.0%) did not have a revision or reoperation for PJI recorded. In a multivariate logistic regression analysis, early (within 30 days of implantation) PJIs were less likely to be reported (adjusted odds ratio (OR) 0.56; 95% confidence interval (CI) 0.34 to 0.93; p = 0.020), while two-stage revision procedures were more likely to be reported as a PJI to the registry (OR 5.3 (95% CI 2.37 to 14.0); p ≤ 0.001) than debridement and implant retention or other surgical procedures. Based on this data, the true estimate of the incidence of PJI in Australia is up to 3,900 cases per year.

Conclusion

In Australia, infection was not recorded as the indication for revision or reoperation in one-quarter of those with confirmed PJI. This is better than in other registries, but suggests that registry-captured estimates of the total national burden of PJI are underestimated by at least one-third. Inconsistent PJI reporting is multifactorial but could be improved by developing a nested PJI registry embedded within the national arthroplasty registry.

Cite this article: Bone Jt Open 2022;3(5):367–373.

Fatal Clostridium Infection in a Leg-Amputated Patient after Unsuccessful Knee Arthroplasty

Prosthetic joint infection (PJI) is a possible complication occurring after prosthesis implantation. We describe the case of a patient with early postoperative multidrug-resistant polymicrobial PJI and mixed infection of the surgical wound. Despite the removal of the prosthesis, the positioning of double-stage exchange, and dehiscence debridement of the surgical wound, the infection continued. Positioning of an external fixator, plastic reconstruction with a skin graft, and continuous (two years) multiple antimicrobial therapy led to the resolution of the knee infection; a knee prosthesis was implanted, but a new infection of the extensus apparatus by multidrug-resistant Klebsiella pnumoniae followed. It was complicated by surgical wound dehiscence, forcing us to remove the prosthesis, put a new external fixator, and continue with the antibiotic treatment, with no results, and, finally, proceed to a leg amputation. Fourteen days after, the patient was discharged in good clinical condition but, fifteen days later, during rehabilitation in another hospital, the patient developed a severe Clostridium difficilis infection with profuse, intense diarrhea, toxic megacolon, and septic shock; despite colectomy and treatment in an intensive care unit, he died four months later. Patients affected by polymicrobial PJI are at high risk of treatment failure and, therefore, should be given a warning, in good time and appropriate form, of the likelihood of leg amputation.

Accuracy of Predictive Algorithms in Total Hip and Knee Arthroplasty Acute Periprosthetic Joint Infections Treated With Debridement, Antibiotics, and Implant Retention (DAIR)

BACKGROUND

Debridement, antibiotics, and implant retention (DAIR) failure remains high for total hip and knee arthroplasty periprosthetic joint infection (PJI). We sought to determine the predictive value of the CRIME80 and KLIC for failure of DAIR in acute hematogenous (AH) and acute postoperative (AP) PJIs, respectively.

METHODS

We identified 134 patients who underwent DAIR for AH PJI with <4 weeks of symptoms after index arthroplasty and 122 patients who underwent DAIR for AP PJI <90 days from index. In the AH group, 15 patients (11%) failed at 90 days and overall, 33 (25%) had failed by 2 years. In the AP group, 39 (32%) failed at 90 days and overall, 52 (43%) failed by 2 years. Logistic regression models were used to determine the area under the curve (AUC) to establish thresholds using the Youden index.

RESULTS

For the AP cohort, AUCs were below 0.66 for KLIC, Charlson comorbidity index, Elixhauser comorbidity index, and McPherson host grade. For the AH cohort, 90-day AUCs were 0.70 for CRIME80 and below 0.66 for Charlson comorbidity index, Elixhauser comorbidity index, and McPherson host grade. In multivariate analysis controlling for age, sex, and body mass index, the CRIME80 AUC improved to 0.77 at 90 days.

CONCLUSION

To the authors' knowledge, this study represents the first external validation of the KLIC and CRIME80 for predicting DAIR failure in a North American population. The results indicate that alternative methods for predicting DAIR failure at 90 days and 2 years for acute PJI are needed.

LEVEL OF EVIDENCE

Prognostic III.

2021 Chitranjan S. Ranawat Award: Intraosseous vancomycin reduces periprosthetic joint infection in primary total knee arthroplasty at 90-day follow-up

AIMS

Infection complicating primary total knee arthroplasty (TKA) is a common reason for revision surgery, hospital readmission, patient morbidity, and mortality. Increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) is a particular concern. The use of vancomycin as prophylactic agent alone or in combination with cephalosporin has not demonstrated lower periprosthetic joint infection (PJI) rates, partly due to timing and dosing of intravenous (IV) vancomycin administration, which have proven important factors in effectiveness. This is a retrospective review of a consecutive series of primary TKAs examining incidence of PJI, adverse reactions, and complications using IV versus intraosseous (IO) vancomycin at 30-day, 90-day, and one-year follow-up.

METHODS

A retrospective review of 1,060 patients who underwent TKA between May 2016 to July 2020 was performed. There were 572 patients in the IV group and 488 in the IO group, with minimal 30 days of follow-up. Patients were followed up at regularly scheduled intervals (two, six, and 12 weeks). No differences between groups for age, sex, BMI, or baseline comorbidities existed. The IV group received an IV dose of 15 mg/kg vancomycin given over an hour preceding skin incision. The IO group received a 500 mg dose of vancomycin mixed in 150 ml of normal saline, injected into proximal tibia after tourniquet inflation, before skin incision. All patients received an additional dose of first generation cephalosporin. Evaluation included preoperative and postoperative serum creatinine values, tourniquet time, and adverse reactions attributable to vancomycin.

RESULTS

Incidence of PJI with minimum 90-day follow-up was 1.4% (eight knees) in the IV group and 0.22% (one knee) in IO group (p = 0.047). This preliminary report demonstrated an reduction in the incidence of infection in TKA using IO vancomycin combined with a first-generation cephalosporin. While the study suffers from limitations of a retrospective, multi-surgeon investigation, early findings are encouraging.

CONCLUSION

IO delivery of vancomycin after tourniquet inflation is a safe and effective alternative to IV administration, eliminating the logistical challenges of timely dosing. Cite this article: Bone Joint J 2021;103-B(6 Supple A):13-17.

Epidemiology of complex bone and joint infections in France using a national registry: The CRIOAc network

OBJECTIVES

In France, a network of reference centers for bone and joint infections (BJI) was created in 2008, focused on the management of complex BJI (previous failure, difficult-to-treat microorganisms, heavy comorbidities or surgical procedures). A national registry was implemented from 2012, collecting decisions advised in periodic multidisciplinary meetings. We present here an epidemiological overview.

METHODS

All consecutive adult patients presented from 2014 to 2019 in 23/30 reference centers were included in this cohort. Characteristics of patients, BJI, and medico-surgical management advice were described.

RESULTS

27,483 individual patients were included, corresponding to 28,365 distinct infectious episodes, which 17,328 were complex. Median age was 65 years, with 62% of men, 1/3 patients presented more than 2 comorbidities. Prosthetic joint infections (PJI) represented 42% of all BJIs (11,812 episodes). Staphylococcus aureus, coagulase-negative staphylococci and polymicrobial PJI represented 26%, 25% and 16% respectively. DAIR (debridement, antibiotics and implant retention) was proposed for 3,157 (27%), whereas one-stage and two-stage revision for 3,683 (31%) and 1,764 (15%). An antibiotic treatment was advised in 10,493 episodes (87%), with combination therapy in 88%.

CONCLUSION

This national network allows an optimized management of complex BJIs. Its cohort is a unique opportunity to draw up a detailed epidemiological picture and to follow the trends of these infrequent infections.

Prosthetic joint infection. A relevant public health issue

Prosthetic joint infection (PJI) is a common complication of the knee and hip arthroplasty and represents a huge challenge for physicians. PJI raises serious social, economic and clinical concerns in the public health that need a comprehensive approach to better focus on proven strategies for disease prevention and treatment. History and clinical signs on joint site are useful means for suspecting PJI that need to be confirmed through major and minor diagnostic criteria. The pathogen isolation and the resulting antibiogram are crucial to guide the correct antibiotic strategy and together with surgical treatment (prosthesis revision and spacer implantation) represent the cornerstones to eradicate the infection before attempting a new arthroplasty. External fixator with removal of the spacer may be an option before performing a new arthroplasty when the infection does not heal. Arthrodesis may also be considered if the arthroplasty is contraindicated. Limb amputation is the last chance when pathogen eradication failed and might lead to life-threatening situations.

Identification of prosthetic hip and knee joint infections using administrative databases-A validation study

OBJECTIVE

To determine whether combinations of diagnosis and procedures codes can improve the detection of prosthetic hip and knee joint infections from administrative databases.

DESIGN

We performed a validation study of all readmissions from January 1, 2010, until December 31, 2016, following primary arthroplasty comparing the diagnosis and procedure codes obtained from an administrative database based upon the International Classification of Disease, Tenth Revision (ICD-10) to the reference standard of chart review.

SETTING

Four tertiary-care hospitals in Toronto, Canada, from 2010 to 2016.

PARTICIPANTS

Individuals who had a primary arthroplasty were identified using procedure codes.

INTERVENTION

Chart review of readmissions identified the presence of a prosthetic joint infection and, if present, the surgical procedure performed.

RESULTS

Overall, 27,802 primary arthroplasties were performed. Among 8,844 readmissions over a median follow-up of 669 days (interquartile range, 256-1,249 days), a PJI was responsible for or present in 586 of 8,844 (6.6%). Diagnosis codes alone exhibited a sensitivity of 0.88 (95% CI, 0.85-0.92) and positive predictive value (PPV) of 0.78 (95% CI, 0.74-0.82) for detecting a PJI. Combining a PJI diagnosis code with procedure codes for an arthroplasty and the insertion of a peripherally inserted central catheter improved detection: sensitivity was 0.92 (95% CI, 0.88-0.94) and PPV was 0.78 (95% CI, 0.74-0.82). However, procedure codes were unable to identify the specific surgical approach to PJI treatment.

CONCLUSIONS

Compared to PJI diagnosis codes, combinations of diagnosis and procedure codes improve the detection of a PJI in administrative databases.

High prevalence of older Australians with one or more joint replacements: estimating the population at risk for late complications of arthroplasty

BACKGROUND

To provide an estimate of the population at risk for late complications of arthroplasty, we aimed to determine the prevalence of Australians living with one or more joint replacements.

METHODS

Data included all arthroplasty procedures performed in Australia from 2003 to 2016 recorded by the Australian Orthopaedic Association National Joint Replacement Registry. The age- and gender-specific Australian population was obtained from the Australian Bureau of Statistics and used as denominator data. Survival data for each joint replacement, and of individuals, were used to estimate the arthroplasty prevalence. Analyses by age, gender and joint replacement site were undertaken. Prevalence estimates were augmented with procedural data captured before 2003 modelled with assumptions accounting for age and gender distributions, overall survival and arthroplasty revision rates.

RESULTS

By the end of 2016, there were 824 769 Australians living with at least one joint replacement, representing 3.4% of the total population. The prevalence of joint replacement is increasing in all age groups, but was highest amongst older Australians, with an overall prevalence of 22.5%, and 13.3% in those aged >85 years and 65-84 years, respectively. The prevalence of people living with multiple joint replacements is increasing more rapidly than patients who have undergone only one joint replacement procedure.

CONCLUSION

The prevalence of older Australians living with joint replacements is rapidly increasing, providing an estimate of the population-at-risk for late complications of arthroplasty including peri-prosthetic infection and fracture.

Severe maternal morbidity during delivery hospitalisation in a large international administrative database, 2008-2013: a retrospective cohort

OBJECTIVE

This study utilized the Dr. Foster Global Comparators database to identify pregnancy complications and associated risk factors that led to severe maternal morbidity during delivery hospitalisations in large university hospitals based in the USA, Australia, and England.

DESIGN

Retrospective cohort.

SETTING

Births in the USA, England and Australia from 2008 to 2013.

SAMPLE

Data from delivery hospitalisations between 2008 and 2013 were examined using the Dr. Foster Global Comparators database.

METHODS

We identified delivery hospitalisations with life-threatening diagnoses or use of life-saving procedures, using algorithms for severe maternal morbidity from the Center for Disease Control. Frequency of severe maternal morbidity was calculated for each country.

MAIN OUTCOME MEASURES

Multivariable analysis was used to examine the association between morbidity and socio-demographic and clinical characteristics within each country. Chi-square tests assessed differences in covariates between countries.

RESULTS

From 2008 to 2013, there were 516 781 deliveries from a total of 18 hospitals: 24.5% from the USA, 57.0% from England and 18.4% from Australia. Overall severe maternal morbidity rate was 8.2 per 1000 deliveries: 15.6 in the USA, 5.0 in England, and 8.2 in Australia. The most common codes identifying severe morbidity included transfusion, disseminated intravascular coagulation, acute renal failure, cardiac events/procedures, ventilation, hysterectomy, and eclampsia. Advanced maternal age, hypertension, diabetes, and substance abuse were associated with severe maternal morbidity in all three countries.

CONCLUSION

Rates of severe maternal morbidity differed by country. Identification of geographical, socio-demographic, and clinical differences can help target modifications of practice and potentially reduce severe maternal morbidity.

TWEETABLE ABSTRACT

Rates of severe maternal morbidity vary, but risk factors associated with adverse outcomes are similar in developed countries.

Multidrug-resistant and extensively drug-resistant Gram-negative prosthetic joint infections: Role of surgery and impact of colistin administration

Factors influencing treatment outcome of patients with Gram-negative bacterial (GNB) multidrug-resistant (MDR) and extensively drug-resistant (XDR) prosthetic joint infection (PJIs) were analysed. Data were collected (2000-2015) by 18 centres. Treatment success was analysed by surgery type for PJI, resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) using logistic regression and survival analyses. A total of 131 patients (mean age 73.0 years, 35.9% male, 58.8% with co-morbidities) with MDR (n = 108) or XDR (n = 23) GNB PJI were assessed. The most common pathogens were Escherichia coli (33.6%), Pseudomonas aeruginosa (25.2%), Klebsiella pneumoniae (21.4%) and Enterobacter cloacae (17.6%). Pseudomonas aeruginosa predominated in XDR cases. Isolates were carbapenem-resistant (n = 12), fluoroquinolone-resistant (n = 63) and ESBL-producers (n = 94). Treatment outcome was worse in XDR versus MDR cases (P = 0.018). Success rates did not differ for colistin versus non-colistin in XDR cases (P = 0.657), but colistin was less successful in MDR cases (P = 0.018). Debridement, antibiotics and implant retention (DAIR) (n = 67) was associated with higher failure rates versus non-DAIR (n = 64) (OR = 3.57, 95% CI 1.68-7.58; P < 0.001). Superiority of non-DAIR was confirmed by Kaplan-Meir analysis (HR = 0.36, 95% CI 0.20-0.67) and remained unchangeable by time of infection (early/late), antimicrobial resistance (MDR/XDR) and antimicrobials (colistin/non-colistin) (Breslow-Day, P = 0.737). DAIR is associated with higher failure rates even in early MDR/XDR GNB PJIs versus implant removal. Colistin should be preserved for XDR cases as it is detrimental in MDR infections.

Antibacterial and immunogenic behavior of silver coatings on additively manufactured porous titanium

Implant-associated infections (IAI) are often recurrent, expensive to treat, and associated with high rates of morbidity, if not mortality. We biofunctionalized the surface of additively manufactured volume-porous titanium implants using electrophoretic deposition (EPD) as a way to eliminate the peri-operative bacterial load and prevent IAI. Chitosan-based (Ch) coatings were incorporated with different concentrations of silver (Ag) nanoparticles or vancomycin. A full-scale in vitro and in vivo study was then performed to evaluate the antibacterial, immunogenic, and osteogenic activity of the developed implants. In vitro, Ch + vancomycin or Ch + Ag coatings completely eliminated, or reduced the number of planktonic and adherent Staphylococcus aureus by up to 4 orders of magnitude, respectively. In an in vivo tibia intramedullary implant model, Ch + Ag coatings caused no adverse immune or bone response under aseptic conditions. Following Staphylococcus aureus inoculation, Ch + vancomycin coatings reduced the implant infection rate as compared to chitosan-only coatings. Ch + Ag implants did not demonstrate antibacterial effects in vivo and even aggravated infection-mediated bone remodeling including increased osteoclast formation and inflammation-induced new bone formation. As an explanation for the poor antibacterial activity of Ch + Ag implants, it was found that antibacterial Ag concentrations were cytotoxic for neutrophils, and that non-toxic Ag concentrations diminished their phagocytic activity. This study shows the potential of EPD coating to biofunctionalize porous titanium implants with different antibacterial agents. Using this method, Ag-based coatings seem inferior to antibiotic coatings, as their adverse effects on the normal immune response could cancel the direct antibacterial effects of Ag nanoparticles. STATEMENT OF SIGNIFICANCE: Implant-associated infections (IAI) are a clinical, societal, and economical burden. Surface biofunctionalization approaches can render complex metal implants with strong local antibacterial action. The antibacterial effects of inorganic materials such as silver nanoparticles (Ag NPs) are often highlighted under very confined conditions in vitro. As a novelty, this study also reports the antibacterial, immunogenic, and osteogenic activity of Ag NP-coated additively-manufactured titanium in vivo. Importantly, it was found that the developed coatings could impair the normal function of neutrophils, the most important phagocytic cells protecting us from IAI. Not surprisingly, the Ag NP-based coatings were outperformed by an antibiotic-based coating. This emphasizes the importance of also targeting implant immune-modulatory functions in future coating strategies against IAI.

Musculoskeletal Infections in the Emergency Department

Bone and joint infections are potentially limb-threatening or even life-threatening diseases. Emergency physicians must consider infection when evaluating musculoskeletal complaints, as misdiagnosis can have significant consequences. Patients with bone and joint infections can have heterogeneous presentations with nonspecific signs and symptoms. Staphylococcus aureus is the most commonly implicated microorganism. Although diagnosis may be suggested by physical examination, laboratory testing, and imaging, tissue sampling for Gram stain and microbiologic culture is preferable, as pathogen identification and susceptibility testing help optimize long-term antibiotic therapy. A combination of medical and surgical interventions is often necessary to effectively manage these challenging infections.

The Role of One-Stage Exchange for Prosthetic Joint Infection

PURPOSE OF REVIEW

In an era of increasing numbers of hip and knee replacements, strategies to manage prosthetic joint infection (PJI) that are effective at infection control with good patient-reported outcomes and cost containment for health systems are needed. Interest in single-stage exchange for PJI is rising and we assess evidence from the last 5 years related to this treatment strategy.

RECENT FINDINGS

Only five series for total knee replacement and ten series for total hip replacement have been reported in the last five years. More review articles and opinion pieces have been written. Reinfection rates in these recent studies range from 0 to 65%, but a meta-analysis and systematic review of all studies showed a reinfection rate of 7.6% (95% CI 3.4-13.1) and 8.8% (95% CI 7.2-10.6) for single-stage and two-stage revisions respectively. There is emerging evidence to support single-stage revision in the setting of significant bony deficiency and atypical PJIs such as fungal infections. Prospective randomised studies are recruiting and are necessary to guide the direction of single-stage revision selection criteria. The onus of surgical excellence in mechanical removal of implants, necrotic tissue, and biofilms lies with the arthroplasty surgeon and must remain the cornerstone of treatment. Single-stage revision may be considered the first-line treatment for all PJIs unless the organism is unknown, the patient is systemically septic, or there is a poor tissue envelope.

Comparison of Diagnostic Accuracy of Periprosthetic Tissue Culture in Blood Culture Bottles to That of Prosthesis Sonication Fluid Culture for Diagnosis of Prosthetic Joint Infection (PJI) by Use of Bayesian Latent Class Modeling and IDSA PJI Criteria for Classification

We have previously demonstrated that culturing periprosthetic tissue in blood culture bottles (BCBs) improves sensitivity compared to conventional agar and broth culture methods for diagnosis of prosthetic joint infection (PJI). We have also shown that prosthesis sonication culture improves sensitivity compared to periprosthetic tissue culture using conventional agar and broth methods. The purpose of this study was to compare the diagnostic accuracy of tissue culture in BCBs (subsequently referred to as tissue culture) to prosthesis sonication culture (subsequently referred to as sonicate fluid culture). We studied 229 subjects who underwent arthroplasty revision or resection surgery between March 2016 and October 2017 at Mayo Clinic in Rochester, Minnesota. Using the Infectious Diseases Society of America (IDSA) PJI diagnostic criteria (omitting culture criteria) as the gold standard, the sensitivity of tissue culture was similar to that of the sonicate fluid culture (66.4% versus 73.1%, P = 0.07) but was significantly lower than that of the two tests combined (66.4% versus 76.9%, P < 0.001). Using Bayesian latent class modeling, which assumes no gold standard for PJI diagnosis, the sensitivity of tissue culture was slightly lower than that of sonicate fluid culture (86.3% versus 88.7%) and much lower than that of the two tests combined (86.3% versus 99.1%). In conclusion, tissue culture in BCBs reached sensitivity similar to that of prosthesis sonicate fluid culture for diagnosis of PJI, but the two tests combined had the highest sensitivity without compromising specificity. The combination of tissue culture in BCBs and sonicate fluid culture is recommended to achieve the highest level of microbiological diagnosis of PJI.

Research progress of asymptomatic bacteriuria before arthroplasty: A systematic review

BACKGROUND

A high prevalence of asymptomatic bacteriuria exists in patients prior to arthroplasty, and urinary tract infection is considered to be a source of postoperative superficial wound and prosthetic joint infections. There is no consensus whether to screen for and treat asymptomatic bacteriuria before arthroplasty.

OBJECTIVE

To summarize the association between asymptomatic bacteriuria and complications after arthroplasty and to evaluate the clinical benefits of treating asymptomatic bacteriuria prior to arthroplasty.

METHOD

We systematically searched PubMed, Embase, and the Cochrane Library to retrieve potentially eligible articles. By screening the titles and abstracts of retrieved records and then reading the full texts of the remaining papers, we finally included 8 English-language articles in this systematic review.

RESULTS

Asymptomatic bacteriuria prior to arthroplasty is significantly associated with an increased occurrence of postoperative prosthetic joint and superficial wound infections. However, there is little evidence for direct or hematogenous seeding of urinary infections, and treating asymptomatic bacteriuria before arthroplasty did not decrease the incidence of postoperative infectious complications.

CONCLUSION

Asymptomatic bacteriuria is not a contraindication for arthroplasty, and the practice of routine preoperative screening for and treatment of asymptomatic bacteriuria should not be continued.