Conservative medical therapy of prosthetic joint infections: retrospective analysis of an 8-year experience

Suppressive Antibiotic Therapy in Prosthetic Joint Infections: A Contemporary Overview

The management of prosthetic joint infections (PJIs) poses significant challenges, requiring a multidisciplinary approach involving surgical, microbiological, and pharmacological expertise. Suppressive antibiotic therapy (SAT) has emerged as a viable option in cases where curative interventions are deemed unfeasible. This review provides an updated synthesis of recent evidence on SAT, including its indications, efficacy, practical considerations, and associated challenges. We aim to highlight the nuances of this therapeutic approach, discuss the factors influencing its success, and offer future directions for research to optimize patient outcomes.

Dosing and treatment duration of suppressive antimicrobial therapy in orthopedic implant infections: a cohort study

Introduction: Limited data inform about the optimal dosing and duration of suppressive antimicrobial therapy (SAT) for orthopedic implant infection (OII). We aimed to compare the effectiveness of low-dosage with standard-dosage SAT and evaluate the safety of stopping SAT. Methods: All patients with OII treated with SAT from 2011 to 2022 were retrospectively included. Data were extracted from electronic patient files. Low-dosage SAT was defined as antimicrobial therapy dosed lower than the standard dosage recommended for OII. The association of dosing strategy and other factors with failure-free survival were assessed by Kaplan-Meier and Cox proportional hazard models. Results: One-hundred-and-eight patients were included. The median follow-up time after SAT initiation was 21 months (interquartile range (IQR) 10-42 months). SAT was successful in 74 patients (69 %). Low-dosage SAT ( n = 82 ) was not associated with failure in univariate (hazard ratio (HR) 1.23, 95 % confidence interval (CI) 0.53-2.83) and multivariate analyses (HR 1.24, 95 % CI 0.54-2.90). In 25 patients (23 %), SAT was stopped after a median treatment duration of 26 months. In this group, one patient (4 %) developed a relapse. Conclusions: In this study, low-dosage SAT was as effective as standard dosage SAT. Moreover, stopping SAT after 2 to 3 years may be justified in patients with a good clinical course. These findings warrant further research on optimal dosing and duration of SAT and on the durability of in vivo biofilms.

How We Approach Suppressive Antibiotic Therapy Following Debridement, Antibiotics, and Implant Retention for Prosthetic Joint Infection

The optimal treatment of prosthetic joint infection (PJI) remains uncertain. Patients undergoing debridement, antibiotics, and implant retention (DAIR) receive extended antimicrobial treatment, and some experts leave patients at perceived highest risk of relapse on suppressive antibiotic therapy (SAT). In this narrative review, we synthesize the literature concerning the role of SAT to prevent treatment failure following DAIR, attempting to answer 3 key questions: (1) What factors identify patients at highest risk for treatment failure after DAIR (ie, patients with the greatest potential to benefit from SAT), (2) Does SAT reduce the rate of treatment failure after DAIR, and (3) What are the rates of treatment failure and adverse events necessitating treatment discontinuation in patients receiving SAT? We conclude by proposing risk-benefit stratification criteria to guide use of SAT after DAIR for PJI, informed by the limited available literature.

Enough is enough: salvage procedures in severe periprosthetic joint infection

BACKGROUND

In severe cases of periprosthetic joint infection involving negative host-dependent factors, individual-based decisions between a curative therapy vs. salvage procedure are necessary. We aimed to review salvage procedures in severe periprosthetic joint infection cases, where a gold standard of a curative two-stage exchange can no longer be achieved. The options of knee arthrodesis, amputation, persistent fistula (stable drainage), or a debridement, antibiotics, and implant retention procedure in late-onset cases are discussed, including lifelong antibiotic suppression alone.

METHODS

We focused on known salvage procedures for severe periprosthetic joint infection of the hip and knee, such as amputation, arthrodesis, antibiotic suppression, persistent fistula, and debridement, antibiotics, and implant retention in late-stage infections, and the role of local antibiotics. The current literature regarding indications and outcomes was reviewed.

RESULTS

Whereas a successful single-stage above-knee amputation can be a curative effort in younger patients, this is associated with limited outcome in older patients, as the proportion who receive an exoprosthesis leading to independent mobility is low. Therefore, arthrodesis using an intramedullary modular nail is an option for limb salvage, pain reduction, and preservation of quality of life and everyday life mobility, when revision total knee arthroplasty is not an option. Carrying out a persistent fistula using a stable drainage system, as well as a lifelong antibiotic suppression therapy, can be an option, in cases where no other surgery is possible. Active clinical surveillance should then be carried out. A debridement, antibiotics, and implant retention procedure in combination with local degradable antibiotics can be used and is an encouraging new option, but should not been carried out twice.

CONCLUSION

Whereas the gold standard in periprosthetic joint infection treatment of late infections remains the exchange of the prosthesis, salvage procedures should be considered in the cases of reduced life expectancy, several recurrences of the infection, patients having preference and negative host factors. In these cases, the appropriate salvage procedure can temporarily lead to remission of the infection and the possibility to maintain mobility.

Pharmacokinetic and pharmacodynamic considerations for optimizing antimicrobial therapy used to treat bone and joint infections: an evidence-based algorithmic approach

INTRODUCTION

Bone and joint infections (BJIs) are a major health concern causing remarkable morbidity and mortality. However, which antimicrobial treatment could be the best according to specific clinical scenarios and/or to the pharmacokinetic/pharmacodynamic (PK/PD) features remains an unmet clinical need. This multidisciplinary opinion article aims to develop evidence-based algorithms for empirical and targeted antibiotic therapy of patients affected by BJIs.

AREAS COVERED

A multidisciplinary team of four experts had several rounds of assessment for developing algorithms devoted to empirical and targeted antimicrobial therapy of BJIs. A literature search was performed on PubMed-MEDLINE (until April 2023) to provide evidence for supporting therapeutic choices. Four different clinical scenarios were structured according to specific infection types (i.e. vertebral osteomyelitis, prosthetic joint infections, infected non-unions and other chronic osteomyelitis, and infectious arthritis), need or not of surgical intervention or revision, isolation or not of clinically relevant bacterial pathogens from blood and/or tissue cultures, and PK/PD features of antibiotics.

EXPERT OPINION

The proposed therapeutic algorithms were based on a multifaceted approach considering the peculiar features of each antibiotic (spectrum of activity, PK/PD properties, bone penetration rate, and anti-biofilm activity), and could be hopefully helpful in improving clinical outcome of BJIs.

Conservative Management First Strategy in Aortic Vascular Graft and Endograft Infections

OBJECTIVE

The aim of this study was to describe and present the outcomes of a specific treatment protocol for aortic vascular graft and endograft infections (VGEIs) without explantation of the infected graft.

METHODS

This was a retrospective, observational single centre cohort study carried out between 2012 and 2022 at a tertiary hospital. An aortic VGEI was defined according to the Management of Aortic Graft Infection Collaboration (MAGIC) criteria. Fitness for graft excision was assessed by a multidisciplinary team and included an evaluation of the patient's general condition, septic status, and anatomical complexity. Antimicrobial treatments were individualised. The primary outcome was survival at the last available follow up; secondary outcomes were antimicrobial treatment duration, infection eradication, treatment failure despite antimicrobial treatment, and the development of aortic fistulation.

RESULTS

Fifty patients were included in the study, of whom 42 (84%) had had previous endovascular repair. The median patient age was 72 years (range 51 - 82 years) and median duration of treatment with antimicrobials was 18 months (range 1 - 164 months). Kaplan-Meier analysis estimated the 30 day survival to be 98% (95% confidence interval [CI] 96 - 100), the one year survival rate to be 88% (95% CI 83.4 - 92.6), and the three year survival rate to be 79% (95% CI 72.7 - 84.7). Twenty-four (48%) patients were able to discontinue antibiotic treatment after a median of 16 months (range 4 - 81 months). When categorised according to infected graft location, deaths occurred in four (40%) patients with thoracic, two (40%) with paravisceral, seven (30%) with infrarenal VGEIs, and in one (25%) patient with an aorto-iliac VGEI; no (0%) patient with a thoraco-abdominal VGEI died.

CONCLUSION

Identifying the microbiological aetiology in patients with aortic VGEI enables individualised, specific antibiotic treatment, which may be useful in patients with a VGEI excluded from surgery. This single centre retrospective analysis of patients with VGEIs without fistula selected for conservative treatment suggests that conservative management of aortic VGEIs with targeted antibiotic therapy without graft excision is potentially effective, and that antimicrobial treatment will not necessarily be needed indefinitely.

Chronic Suppressive Antibiotic Treatment for Staphylococcal Bone and Joint Implant-Related Infections

Prosthetic joint infection (PJI) and fracture-related infection (FRI) are difficult-to-treat conditions in patients with severe comorbidity or significant surgical risk. In cases not eligible for standard strategy, debridement procedures with the retention of prosthesis or internal fixation device, combined with long-term antibiotic treatment and subsequent indefinite chronic oral antimicrobial suppression (COAS), can be the only reasonable choice. The aim of this study was to investigate the role of COAS and its follow-up in the management of these cases. We retrospectively analyzed a cohort of 16 patients with a follow-up of at least 6 months (mean age 75 yo, 9F, 7M, 11 PJI, 5 FRI). All microbiological isolates were tetracycline-susceptible staphylococci and for this reason a minocycline-based COAS was adopted after debridement and 3 months of antibiogram-guided antibiotic treatment. Patient monitoring was carried out on a clinical basis, with bimonthly execution of the inflammation indices and serial radiolabeled leukocyte scintigraphy (LS). The overall median time of COAS follow-up was 15 months (min 6-max 30). Moreover, 62.5% of patients were still taking COAS with no relapse after cure at the last evaluation available. Clinical failure with a relapse of the infection was observed in 37.5% of patients; interestingly, 50% of them had previously stopped COAS due to side effects of the antibiotic used. In the COAS follow-up, a combination of clinical, laboratory and LS evaluation seems to monitor the infection properly. COAS can be considered as an interesting approach in patients not suitable for standard treatments of PJI or FRI but it requires careful monitoring.

Diagnosis and treatment of periprosthetic infection after hip replacement (a review)

Introduction. The frequency of hip arthroplasty is steadily increasing throughout the world and, although this operation has become routine, the likelihood of postoperative complications reaches 4.3 % [1]. The most dangerous of them are infectious lesions in the area of the endoprosthesis and adjacent tissues. At the same time, in addition to the threat of generalization of the infectious process, there are functional disorders in the joint area and a general deterioration in the quality of life of the patient. Timely diagnosis and treatment of the infectious process and related disorders can minimize the adverse effects of infection.

Target. The purpose of this review is to analyze modern methods for diagnosing and treating periprosthetic infection resulting from hip replacement.

Materials and methods. The subject literature was searched using the PubMed and Google Sholar databases.

Results. The main methods for diagnosing periprosthetic infection include histological and bacteriological examination of the biopsy specimen, determination of sensitivity to antibiotics, blood, and synovial fluid analysis for the content of leukocytes, IL-6, CRP, PCR diagnostics of infectious agents. Treatment consists of re-intervention and/or antibiotic therapy.

Conclusion. The most optimal method for diagnosing periprosthetic infection is a bacteriological study of biopsy specimens taken intraoperatively. The preferred method of treatment is determined by the severity of the infection, the degree of involvement of tissues adjacent to the prosthesis, the comorbid background, the nature of the infectious agent, and includes repeated revision surgery.

Predictors of Success With Chronic Antibiotic Suppression for Prosthetic Joint Infections

BACKGROUND

Management of recurrent prosthetic joint infection (PJI) after attempted surgical eradication remains a challenge. Chronic antibiotic suppression (CAS) is regarded as a reasonable treatment option for select patients with persistent infection or multiple comorbidities. The study seeks to compare cohorts who succeed and fail with CAS.

METHODS

This retrospective cohort study assesses patients who were treated with CAS for a PJI. Patients were included if they had a culture-proven PJI and received chronic suppressive antibiotics. Failure of suppression was defined as reoperation after initiating CAS or death occurring as result of infection. A Cox proportional hazards multivariate regression model was used to estimate risk of reoperation as a function of risk factors related to patient comorbidities, surgical history, affected joint, and infecting organism.

RESULTS

We identified 45 PJIs (31 knees, 14 hips) managed with CAS with a median follow-up of 50 (95% confidence interval [CI] 33.61-74.02) months. The overall success rate of managing PJI with CAS was 67% (30/45). Controlling for body mass index and Gram status of the organism, total hip arthroplasty patients were less likely than total knee arthroplasty patients to require reoperation (hazard ratio 0.18, 95% CI 0.01-0.96, P = .04). Patients with Gram-positive infections were less likely than those with a Gram-negative infections to require reoperation (hazard ratio 0.22, 95% CI 0.05-0.88, P = .03). Severe antibiotic side effects were rare. Patients who experienced multiple changes to their antibiotic regimen were more likely to fail with CAS.

CONCLUSION

CAS is a reasonable strategy in patients with PJI who lack or refuse further surgical treatment options. Most hips and Gram-positive infections treated with CAS successfully avoided reoperation in this cohort.

Orthopaedic Implant-Associated Staphylococcal Infections: A Critical Reappraisal of Unmet Clinical Needs Associated with the Implementation of the Best Antibiotic Choice

Infections associated with orthopaedic implants represent a major health concern characterized by a remarkable incidence of morbidity and mortality. The wide variety of clinical scenarios encountered in the heterogeneous world of infections associated with orthopaedic implants makes the implementation of an optimal and standardized antimicrobial treatment challenging. Antibiotic bone penetration, anti-biofilm activity, long-term safety, and drug choice/dosage regimens favouring outpatient management (i.e., long-acting or oral agents) play a major role in regards to the chronic evolution of these infections. The aim of this multidisciplinary opinion article is to summarize evidence supporting the use of the different anti-staphylococcal agents in terms of microbiological and pharmacological optimization according to bone penetration, anti-biofilm activity, long-term safety, and feasibility for outpatient regimens, and to provide a useful guide for clinicians in the management of patients affected by staphylococcal infections associated with orthopaedic implants Novel long-acting lipoglycopeptides, and particularly dalbavancin, alone or in combination with rifampicin, could represent the best antibiotic choice according to real-world evidence and pharmacokinetic/pharmacodynamic properties. The implementation of a multidisciplinary taskforce and close cooperation between microbiologists and clinicians is crucial for providing the best care in this scenario.

Microbiological pathogen analysis in native versus periprosthetic joint infections: a retrospective study

BACKGROUND

The presence or absence of an implant has a major impact on the type of joint infection therapy. Thus, the aim of this study was the examination of potential differences in the spectrum of pathogens in patients with periprosthetic joint infections (PJI) as compared to patients with native joint infections (NJI).

METHODS

In this retrospective study, we evaluated culture-positive synovial fluid samples of 192 consecutive patients obtained from January 2018 to January 2020 in a tertiary care university hospital. For metrically distributed parameters, Mann-Whitney U was used for comparison between groups. In case of nominal data, crosstabs and Chi-squared tests were implemented.

RESULTS

Overall, 132 patients suffered from periprosthetic joint infections and 60 patients had infections of native joints. The most commonly isolated bacteria were coagulase-negative Staphylococci (CNS, 28%), followed by Staphylococcus aureus (S. aureus, 26.7%), and other bacteria, such as Streptococci (26.3%). We observed a significant dependence between the types of bacteria and the presence of a joint replacement (p < 0.05). Accordingly, detections of CNS occurred 2.5-fold more frequently in prosthetic as compared to native joint infections (33.9% vs. 13.4% p < 0.05). In contrast, S. aureus was observed 3.2-fold more often in NJIs as compared to PJIs (52.2% vs. 16.4%, p < 0.05).

CONCLUSION

The pathogen spectra of periprosthetic and native joint infections differ considerably. However, CNS and S. aureus are the predominant microorganisms in both, PJIs and NJIs, which may guide antimicrobial therapy until microbiologic specification of the causative pathogen.

Biofilm-Related Infections in Gram-Positive Bacteria and the Potential Role of the Long-Acting Agent Dalbavancin

Infections caused by Gram-positive bacteria are a major public health problem due to their increasing resistance to antibiotics. Staphylococcus and Enterococcus species' resistance and pathogenicity are enhanced by their ability to form biofilm. The biofilm lifestyle represents a significant obstacle to treatment because bacterial cells become highly tolerant to a wide range of antimicrobial compounds normally effective against their planktonic forms. Thus, novel therapeutic strategies targeting biofilms are urgently needed. The lipoglycopeptide dalbavancin is a long-acting agent for treating acute bacterial skin and skin structure infections caused by a broad range of Gram-positive pathogens. Recent studies have shown promising activity of dalbavancin against Gram-positive biofilms, including methicillin-resistant S. aureus (MRSA), methicillin-resistant S. epidermidis (MRSE), and vancomycin-susceptible enterococci. This review outlines the mechanisms regulating biofilm development in Staphylococcus and Enterococcus species and the clinical impact of biofilm-related infections. In addition, it discusses the clinical implications and potential therapeutic perspectives of the long-acting drug dalbavancin against biofilm-forming Gram-positive pathogens.

Debridement, Antibiotics, and Implant Retention in Periprosthetic Joint Infection: What Predicts Success or Failure?

BACKGROUND

Debridement, antibiotics and implant retention (DAIR) is the treatment of choice for acute postoperative and acute hematogenous periprosthetic joint infection (PJI). There is limited literature on predictive prognostic factors for DAIR. We aim to report the outcomes of DAIR and investigate the predictive prognostic factors.

METHODS

We retrospectively reviewed 106 DAIRs. Failure was defined as requiring removal of TKA implants. Predictive factors that may influence success of DAIR treatment such as age, gender, body mass index, ethnicity, American Society of Anesthesiologists score, comorbidities, preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein, symptom duration, time between total knee arthroplasty and DAIR, cultures, rifampicin use, polyethylene liner change, and antibiotic duration were analyzed.

RESULTS

The success rate of DAIR was 69.8% (74/106 patients). For successes, mean time from DAIR-to-mortality was longer than failures (61.6 ± 42.7 vs 9.75 ± 9.60 months, P = .0150). Methicillin-susceptible Staphylococcus aureus PJI (odds ratio [OR] 3.64, confidence interval [CI] 1.30-10.2, P = .0140) was a significant predictor for failure of DAIR. Higher preoperative ESR correlated to failure (OR 1.02, CI 1.01-1.04, P = .008). In successes, mean ESR was 75.4 (66.1-84.6), whereas mean ESR in failures was 116 (88.3-143) (P = .011). An ESR > 107.5 predicted failure with a sensitivity of 51.5 and specificity of 85.2. ESR > 107.5 correlated to failure (OR 6.60, CI 2.29-19.0, P < .001). Repeat DAIRs were strongly correlated to failure (OR 5.27, CI 1.99-13.9, P < .01).

CONCLUSION

DAIR failure is associated with earlier time to mortality. Repeat DAIRs, elevated ESR > 107.5, and S aureus PJI are associated with treatment failure and 2-stage revision is recommended.

Suppressive Antibiotic Treatment in Prosthetic Joint Infections: A Perspective

The treatment of prosthetic joint infections (PJIs) is a complex matter in which surgical, microbiological and pharmacological aspects must be integrated and, above all, placed in the context of each patient to make the best decision. Sometimes it is not possible to offer curative treatment of the infection, and in other cases, the probability that the surgery performed will be successful is considered very low. Therefore, indefinite administration of antibiotics with the intention of "suppressing" the course of the infection becomes useful. For decades, we had little information about suppressive antibiotic treatment (SAT). However, due to the longer life expectancy and increase in orthopaedic surgeries, an increasing number of patients with infected joint prostheses experience complex situations in which SAT should be considered as an alternative. In the last 5 years, several studies attempting to answer the many questions that arise on this issue have been published. The aim of this publication is to review the latest published evidence on SAT.

Dalbavancin Efficacy and Impact on Hospital Length-of-Stay and Treatment Costs in Different Gram-Positive Bacterial Infections

Background and Objectives

The study aimed to evaluate the impact of dalbavancin therapy on both hospital length-of-stay (LOS) and treatment-related costs, as well as to describe the clinical outcome, in a retrospective cohort of patients with diverse Gram-positive bacterial infections, hospitalized in different specialty Units.

Methods

From July 2017 to July 2019, clinical and sociodemographic data were collected for all hospitalized patients switched to dalbavancin for the treatment of Gram-positive infections. LOS and treatment-related costs were assessed and compared to a hypothetical scenario where the initial standard antimicrobial therapy would have been administered in hospital for the same duration as dalbavancin.

Results

A total of 50 patients were enrolled. The observed infections were: acute bacterial skin and skin structure infections (ABSSSIs, 12 patients), complicated ABSSSIs (eight patients), osteoarticular infections (18 patients), vascular graft or cardiovascular implantable electronic devices (CIED) infections (12 patients). After a median of 14 [interquartile range (IQR) 7–28] days, the in-hospital antimicrobial therapy was switched to dalbavancin 1500 mg. When appropriate, considering the site and the clinical course of the infection, 1500 mg doses were repeated every 14 days until recovery. Overall, 49/50 (98%) patients reported clinical success at the end of therapy. No relapses were observed in 37 patients for whom a median follow-up of 150 (IQR 30–180) days was available. By switching to dalbavancin, a median of €8,259 (IQR 5644–17,270) and 14 hospital days (IQR 22–47) per patient were saved.

Conclusions

In this experience, the use of dalbavancin contributed to shorten LOS and treatment-related costs, especially in difficult Gram-positive infections requiring prolonged therapy.

Complications of percutaneous image-guided screw fixation: An analysis of 94 consecutive patients

PURPOSE

The purpose of this study was to retrospectively assess the safety profile of percutaneous image-guided screw fixation (PIGSF) for insufficiency, impending or pathological fractures.

MATERIALS AND METHODS

From July 2012 to April 2020, all consecutive patients who underwent PIGSF were retrospectively included in the study. Patient characteristics, fracture type, procedural data and complications were analyzed. Complications were divided into per-procedural, early (<24hours) and delayed (>24hours) and classified into minor (grade 1-2) and major complications (grade 3-5) according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

A total of 110 fractures (40 insufficiency [36%], 53 pathological [48.5%] and 17 impending [15.5%] fractures) in 94 patients (48 women, 46 men; mean age, 62.7±12.7 [SD] years; age range: 32-88 years) were treated with PIGSF during 95 procedures. Twenty-four-hours follow-up was available for all patients, and>24-hours follow-up was available for 79 (79/110; 71.8%) fractures in 69 (69/94; 73.4%) patients. Per-procedural complications occurred in 3/110 fractures (2.7%, all minor). Early complications were reported in 4/110 fractures (3.6%, 1 major and 3 minor) and delayed ones in 14/79 fractures (17.7%, 5 major and 9 minor). The most frequent major delayed complication was infection (3/79; 3.8%).

CONCLUSION

The rate of per-procedural and early (within 24hours) complications following PIGSF is extremely low with most complications being minor, with major complications being delayed ones (>24hours).

Blood and synovial fluid calprotectin as biomarkers to diagnose chronic hip and knee periprosthetic joint infections

AIMS

Calprotectin (CLP) is produced in neutrophils and monocytes and released into body fluids as a result of inflammation or infection. The aim of this study was to evaluate the utility of blood and synovial CLP in the diagnosis of chronic periprosthetic joint infection (PJI).

METHODS

Blood and synovial fluid samples were collected prospectively from 195 patients undergoing primary or revision hip and knee arthroplasty. Patients were divided into five groups: 1) primary total hip and knee arthroplasty performed due to idiopathic osteoarthritis (OA; n = 60); 2) revision hip and knee arthroplasty performed due to aseptic failure of the implant (AR-TJR; n = 40); 3) patients with a confirmed diagnosis of chronic PJI awaiting surgery (n = 45); 4) patients who have finished the first stage of the PJI treatment with the use of cemented spacer and were qualified for replantation procedure (SR-TJR; n = 25), and 5) patients with rheumatoid arthritis undergoing primary total hip and knee arthroplasty (RA; n = 25). CLP concentrations were measured quantitatively in the blood and synovial fluid using an immunoturbidimetric assay. Additionally, blood and synovial CRP, blood interleukin-6 (IL-6), and ESR were measured, and a leucocyte esterase (LE) strip test was performed.

RESULTS

Patients with PJI had higher CLP concentrations than those undergoing aseptic revision in blood (median PJI 2.14 mg/l (interquartile range (IQR) 1.37 to 3.56) vs AR-TJR 0.66 mg/l (IQR 0.3 to 0.83); p < 0.001) and synovial fluid samples (median PJI 20.46 mg/l (IQR 14.3 to 22.36) vs AR-TJR 0.7 mg/l (IQR 0.41 to 0.95); p < 0.001). With a cut-off value of 1.0 mg/l, blood CLP showed a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 87.5%, 89.4%, and 92.1%, respectively. For synovial fluid with a cut-off value of 1.5 mg/l, these were 95.6%, 95%, 95.5%, and 95%, respectively.

CONCLUSION

This small study suggests that synovial and blood CLP are useful markers in chronic PJI diagnosis with similar or higher sensitivity and specificity than routinely used markers such as CRP, ESR, IL-6, and LE. CLP was not useful to differentiate patients with PJI from those with rheumatoid arthritis. Cite this article: Bone Joint J 2021;103-B(1):46-55.

New developments in anti-biofilm intervention towards effective management of orthopedic device related infections (ODRI's)

Orthopedic device related infections (ODRI's) represent a difficult to treat situation owing to their biofilm based nature. Biofilm infections once established are difficult to eradicate even with an aggressive treatment regimen due to their recalcitrance towards antibiotics and immune attack. The involvement of antibiotic resistant pathogens as the etiological agent further worsens the overall clinical picture, pressing on the need to look into alternative treatment strategies. The present review highlightes the microbiological challenges associated with treatment of ODRI's due to biofilm formation on the implant surface. Further, it details the newer anti-infective modalities that work either by preventing biofilm formation and/or through effective disruption of the mature biofilms formed on the medical implant. The study, therefore aims to provide a comprehensive insight into the newer anti-biofilm interventions (non-antibiotic approaches) and a better understanding of their mechanism of action essential for improved management of orthopedic implant infections.

Prevention and Killing Efficacy of Carbapenem Resistant Enterobacteriaceae (CRE) and Vancomycin Resistant Enterococci (VRE) Biofilms by Antibiotic-Loaded Calcium Sulfate Beads

Carbapenem-resistant Enterobacteriaceae (CRE) and vancomycin-resistant Enterococci (VRE) have emerged as multidrug-resistant (MDR) pathogens associated with periprosthetic joint infections (PJI). In this study, we evaluated the efficacy of antibiotic-loaded calcium sulfate beads (ALCSB) in inhibiting bacterial growth, encouraging biofilm formation and killing preformed biofilms of CRE and VRE. Three strains of Klebsiella pneumoniae (KP) and a strain of Enterococcus faecalis (EF) were used. ALCSB of 4.8-mm diameter were loaded with vancomycin (V) and gentamicin (G), V and rifampicin (R), V and tobramycin (T) or R and meropenem (M), and placed onto tryptic soy agar (TSA), spread with one of the test strains and incubated for 24 h at 37 °C. Beads were transferred daily onto fresh TSA spread plates and the zone of inhibition (ZOI) was recorded until no inhibition was observed. ALCSB containing R + M or R + V produced the most extensive ZOI up to 5 weeks. Biofilm prevention efficacy was investigated by challenging ALCSB daily with 5 × 10⁵ CFU/mL bacterial cells and analyzing for biofilm formation at challenges 1, 2 and 3. In the biofilm killing experiments, ALCSB were added to pre-grown 3-day biofilms of KP and EF strains, which were then analyzed at days 1 and 3 post-exposure. The CFU counts and confocal images of the attached cells showed that ALCSB treatment reduced colonization and biofilm formation significantly (5–7 logs) with combinations of R + M or R + V, compared to unloaded beads. This study provides evidence that the local release of antibiotics from ALCSB may be useful in treating the biofilms of multidrug-resistant strains of CRE and VRE.

Salvaging the infected breast implant: results of a retrospective series of 80 consecutive cases

BACKGROUND

Breast implants are widely used in reconstruction after breast cancer. Infection after implant reconstruction is a major complication, with rates ranging from 5 to 30%. This rate is less for pure cosmetic augmentation. Historically, infection of an implant mandated implant removal for sepsis control. An alternative is to attempt to salvage the infected implant. This path can be a long one, requiring surgery for washouts and prolonged antibiotic therapy. This article documents our experience of infected implant salvage over the last 13 years.

METHODS

We conducted a retrospective analysis of all patients who developed a breast implant infection between January 2005 and January 2018. All patients had both clinical signs of infection and a positive bacteriological sample. Patients were divided into two groups: upfront medical therapy (including those requiring secondary surgical salvage) and primary surgery. The salvage procedure was defined as successful when the implant was still in place three months after the initial reconstruction.

RESULTS

Eighty patients were included: 77 in the medical group and 3 in the surgical group. Overall, implant salvage was achieved in 88.8% of women (n=71). Of these, 73.8% (n=59) underwent medical treatment alone and 15% (n=12) underwent medical treatment followed by surgical management. The main causative organism was staphylococcus in 81.2%. When the infection was caused by a coagulase-negative staphylococcus, the rate of success was 98% (p<0.003).

CONCLUSIONS

This case series reports that salvage of an infected breast implant was achievable in up to 90% of women presenting with a documented infection, the majority requiring antibiotic management only. Early intervention is central to success.

DAIR (Debridement, Antibiotics and Implant Retention) less effective in hematogenous total knee arthroplasty infections

Background

Debridement and irrigation with prosthetic retention followed by antibiotic therapy (DAIR) is one of the treatments of choice in acute infections after a total knee arthroplasty. However, the success rate varies widely in the literature, depending on several factors such as comorbidities of the patient, duration of infection, and microorganisms involved. The goal of this study was to assess the outcomes of this therapeutic option and to identify possible predictors of the result.

Methods

We retrospectively reviewed cases of acute postoperative (≤ 3 months from index procedure) and acute hematogenous periprosthetic knee infections treated with DAIR at our hospital between 2004 and 2016. Overall, 26 knees were included, with a mean age of 73.4 years. Several variables related to patient characteristics, infection type, and surgery were examined to evaluate their influence on outcome, and functional and radiographic outcome were assessed. The mean follow-up was 41 months. A descriptive analysis was carried out on the collected data, and a univariate analysis was performed with the objective of searching for influential factors in the resolution of the infection using the chi-square nonparametric test in the case of the categorical variables and the Wilcoxon test for the continuous ones. Moreover, univariate cox regression analysis was performed.

Results

The overall success rate was 77% at the last follow-up, recording a significantly greater cure in acute infections (93% acute vs 58% acute hematogenous, p = 0.03). The infections in which the Staphylococcus aureus was isolated had a significantly lower cure rate, with only 33% of success, compared to 82% of the non-aureus microorganisms (p <  0.05).

Conclusions

The present study shows a considerable cure rate in the treatment of acute knee infections through DAIR, although patient comorbidities, type of infection, and causative microorganism should be considered for decision-making.

Inadequate evaluation and management of suspected -infections after TKA surgery in Lithuania: a retrospective study of 2,769 patients with 2-year follow-up

Background and purpose - The evidence-based algorithms for treatment of periprosthetic joint infection (PJI) recommend surgical intervention in combination with the use of systemic antibiotics. However, still it is not unusual to treat total knee arthroplasty (TKA) patients with suspected infection using only antibiotics. We investigated treatment pathways for TKA patients with suspected infection in Lithuania. Patients and methods - Of the 4,069 TKA patients (4,269 knees) registered in the Lithuanian Arthroplasty Register (2013-2015) 2,769 patients (2,825 knees) were interviewed 2 years after the surgery. The patients were asked if they had been subject to antibiotic treatment after the TKA surgery and/or if any additional surgical interventions on the operated knee had been performed. The number of patients treated with antibiotics due to problems in the operated knee was identified and cumulative revision rates (CRR) were calculated. Results - 180 (7%) patients of the total 2,769 reported that they had been prescribed antibiotics after the primary TKA; 132 of these patients (70%) said they had received antibiotics due to problems with the operated knee. The 2-year CRR after TKA in patients not treated with antibiotics was 0.7% (95% CI 0.4-1), as compared with 24% (95% CI 17-32) in those who had used antibiotics due to the problems in the operated knee for more than 1 week. Interpretation - In Lithuania there seems to be a lack of adherence to evidence-based treatment guidelines when infection is suspected after primary TKA.

Haematogenous prosthetic knee infections: Prospective cohort study of 58 patients

BACKGROUND

Prosthetic joint infection (PJI) is a rare (incidence, 0.15% to 0.9%) but serious complication of knee arthroplasty. Haematogenous PJI of the knee (KhPJI) which accounts for 10% of cases, has been less studied than PJI due to other mechanisms. The primary objective of this study in patients with KhPJI of the knee was to determine the 2-year infection eradication failure rate after either exchange arthroplasty or arthrotomy/synovectomy/irrigation (ASI), combined with prolonged peri-operative antibiotic therapy, at a referral centre for complex osteo-articular infections.

HYPOTHESIS

ASI within 2 weeks after symptom onset and one-stage exchange arthroplasty produce similar 2-year success rates in patients with KhPJI of the knee.

MATERIAL AND METHODS

A prospective observational cohort study was performed in patients managed for PJI of the knee between 2003 and 2015. The primary outcome measure was the occurrence of a septic event or of KhPJI -related death during a minimum follow-up of 2 years.

RESULTS

Of 265 patients with PJI after total knee arthroplasty, 58 (22.1%) had KhPJI with onset more than 3 months after the last arthroplasty procedure and were included in the study. Among them, one-third had immune deficiencies. The most common causative organisms were streptococci (n=25, 43%) and Staphylococcusaureus (n=20, 34%). The primary focus of infection was identified in only 64% of patients and was most often cutaneous (n=19, 33%) or dental (n=11, 19%). A septic event or KhPJI-related death occurred in 5/34 (15%) patients after one-stage exchange arthroplasty and 6/19 (32%) patients after ASI within 15 days after symptom onset (p=0.03). Patient characteristics, type of prosthesis, and causative organism were not significantly associated with failure to eradicate the infection.

CONCLUSION

ASI carried a high failure rate despite being performed within 15 days after symptom onset. One-stage exchange arthroplasty seems to be the best surgical option, particularly as the exact time of symptom onset may be difficult to determine. Identifying and eradicating the primary focus of infection is crucial.

LEVEL OF EVIDENCE

II, low-powered prospective cohort study.

Failed Debridement and Implant Retention Does Not Compromise the Success of Subsequent Staged Revision in Infected Total Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) is the leading cause of early revisions after total knee arthroplasty. Debridement, antibiotics, and implant retention (DAIR) procedures are often the initial treatment for PJI. However, there is concern that failed DAIR undermines the future success of revision procedures. This study aims to investigate the impact of DAIR on the success of subsequent staged revisions for PJI.

METHODS

A multicenter retrospective review was performed over a 15-year period. Treatment success was defined as implant retention without the use of long-term suppressive antibiotics. This was compared between patients who underwent a staged revision as the first procedure for PJI (staged-only) and patients who failed DAIR before staged revision (F-DAIR). Competing risk survival analysis was performed to compare the 2 groups and considered for patient demographics, American Society of Anesthesiologists score, organism type, body mass index, age of prosthesis, and duration of symptoms.

RESULTS

Of 291 eligible patients, 63 underwent staged revision and 228 underwent DAIR as the first procedure for PJI. Of the 228 DAIR patients, 75 failed DAIR and underwent subsequent staged revision (F-DAIR). At mean follow-up of 6.2 years, the success rate was 72% in the F-DAIR group and 81% in the staged-only group. On survival analysis, there was no significant difference in subdistribution hazard ratio comparing the probability of failure (implant retention) in the 2 treatments groups (subdistribution hazard ratio = 0.72; 95% confidence interval 0.32-1.61; P = .42).

CONCLUSION

This study suggested that a previously failed DAIR does not compromise the success rate of a subsequent staged revision.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: management of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. A multidisciplinary team of international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology was assembled to form the International Consensus Group. The following consensus proceedings from the International Consensus Meeting involve 30 questions pertaining to the management of periprosthetic shoulder infection.

Electroceutical Treatment of Pseudomonas aeruginosa Biofilms

Electroceutical wound dressings, especially those involving current flow with silver based electrodes, show promise for treating biofilm infections. However, their mechanism of action is poorly understood. We have developed an in vitro agar based model using a bioluminescent strain of Pseudomonas aeruginosa to measure loss of activity and killing when direct current was applied. Silver electrodes were overlaid with agar and lawn biofilms grown for 24 h. A 6 V battery with 1 kΩ ballast resistor was used to treat the biofilms for 1 h or 24 h. Loss of bioluminescence and a 4-log reduction in viable cells was achieved over the anode. Scanning electron microscopy showed damaged cells and disrupted biofilm architecture. The antimicrobial activity continued to spread from the anode for at least 2 days, even after turning off the current. Based on possible electrochemical ractions of silver electrodes in chlorine containing medium; pH measurements of the medium post treatment; the time delay between initiation of treatment and observed bactericidal effects; and the presence of chlorotyrosine in the cell lysates, hypochlorous acid is hypothesized to be the chemical agent responsible for the observed (destruction/killing/eradication) of these biofilm forming bacteria. Similar killing was obtained with gels containing only bovine synovial fluid or human serum. These results suggest that our in vitro model could serve as a platform for fundamental studies to explore the effects of electrochemical treatment on biofilms, complementing clinical studies with electroceutical dressings.

Clinical Outcome of Massive Endoprostheses Used for Managing Periprosthetic Joint Infections of the Hip and Knee

BACKGROUND

Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. The aim of this study is to determine the mid-term outcome of EPRs performed in the treatment of periprosthetic joint infection (PJI) and infected failed osteosyntheses around the hip and knee joint and identify factors that influence it.

METHODS

We retrospectively reviewed all hip and knee EPRs performed between 2007 and 2014 for the management of chronic infection following complex arthroplasty or fracture fixation. Data recorded included indication for EPR, number of previous surgeries, comorbidities, and organism identified. Outcome measures included PJI eradication rate, complications, implant survival, mortality, and functional outcome (Oxford Hip or Knee Score).

RESULTS

Sixty-nine EPRs (29 knees and 40 hips) were performed with a mean age of 68 years (43-92). Polymicrobial growth was detected in 36% of cases, followed by coagulase-negative staphylococci (28%) and Staphylococcus aureus (10%). Recurrence of infection occurred in 19 patients (28%): 5 were treated with irrigation and debridement, 5 with revision, 1 with above-knee amputation, and 8 remain on long-term antibiotics. PJI eradication was achieved in 50 patients (72%); the chance of PJI eradication was greater in hips (83%) than in knees (59%) (P = .038). The 5-year implant survivorship was 81% (95% confidence interval 74-88). The mean Oxford Hip Score and Oxford Knee Score were 22 (4-39) and 21 (6-43), respectively.

CONCLUSION

This study supports the use of EPRs for eradication of PJI in complex, multiply revised cases. We describe PJI eradication rate of 72% with acceptable functional outcome.

Enterococci in orthopaedic infections: Who is at risk getting infected?

Some orthopaedic patients might be at risk for enterococcal infections and might benefit from adapted perioperative prophylaxis.

METHODS

We performed a single-center cohort of adult patients with orthopaedic infections.

RESULTS

Among 2740 infection episodes, 665 surgeries (24%) involved osteosynthesis material, including total joint arthroplasties. The recommended perioperative prophylaxis was cefuroxime (or vancomycin in case of documented MRSA body carriage). Patients had received antibiotic therapy before surgery in 1167 episodes (43%); among them with potential anti-enterococcal activity (penicillins, glycopeptides, imipenem, linezolid, daptomycin, aminoglycosids, tetracyclins) in 725 (62%) cases. Overall, enterococci were identified in intraoperative samples of 100 different infections (3.6%) (Enterococcus faecalis, 95; Enterococcus faecium, 2; and other enterococci, 3). However, only 15/100 (15%) enterococcal infections were monomicrobial and 19 were nosocomial (19/2740; 0.7%), of which 15 had previous cephalosporin perioperative prophylaxis without other antibiotic exposure. This association to prior cephalosporin use was significant (Pearson-χ²-test; 148/2640 vs. 15/100, p < 0.01). By multivariate analysis, the presence of diabetic foot infection (odds ratio 1.9, 95% confidence interval 1.2-2.9), and polymicrobial infection (OR 6.0, 95%CI 3.9-9.4) were the main predictors of enterococcal infection, while sex, age, and type of material were not.

CONCLUSIONS

Community-acquired or nosocomial enterococcal infections in orthopaedic surgery are mostly polymicrobial, rare and very seldom attributed to a nosocomial origin. Thus, even if they are formally associated with prior cephalosporin use, we do not see a rational for changing our antibiotic prophylaxis.

A minocycline-releasing PMMA system as a space maintainer for staged bone reconstructions-in vitro antibacterial, cytocompatibility and anti-inflammatory characterization

In the present work, we study the development and biological characterization of a polymethyl methacrylate (PMMA)-based minocycline delivery system, to be used as a space maintainer within craniofacial staged regenerative interventions. The developed delivery systems were characterized regarding solid state characteristics and assayed in vitro for antibacterial and anti-inflammatory activity, and cytocompatibility with human bone cells. A drug release profile allowed for an initial burst release and a more sustained and controlled release over time, with minimum inhibitory concentrations for the assayed and relevant pathogenic bacteria (i.e., Staphylococcus aureus, slime-producer Staphylococcus epidermidis and Escherichia coli) being easily attained in the early time points, and sustained up to 72 h. Furthermore, an improved osteoblastic cell response-with enhancement of cell adhesion and cell proliferation-and increased anti-inflammatory activity were verified in developed systems, compared to a control (non minocycline-loaded PMMA cement). The obtained results converge to support the possible efficacy of the developed PMMA-based minocycline delivery systems for the clinical management of complex craniofacial trauma. Here, biomaterials with space maintenance properties are necessary for the management of staged reconstructive approaches, thus minimizing the risk of peri-operative infections and enhancing the local tissue healing and early stages of regeneration.

Efficacy of indefinite chronic oral antimicrobial suppression for prosthetic joint infection in the elderly: a comparative study

BACKGROUND

During prosthetic joint infection (PJI), surgical management is sometimes impossible and indefinite chronic oral antimicrobial suppression (ICOAS) may be the only option. The outcomes of elderly patients who benefited from ICOAS with strictly palliative intent were evaluated.

METHODS

A national retrospective cohort study was performed in France, involving patients aged >75 years with a PJI who were managed with planned life-long ICOAS from 2009 to 2014. Patients who experienced an event were compared to those who did not. An event was defined as a composite outcome in patients undergoing ICOAS, including local or systemic progression of the infection, death, or discontinuation of antimicrobial therapy because of an adverse drug reaction.

RESULTS

Twenty-one patients were included, with a median age of 85 years (interquartile range 81-88 years). Eight of the 21 patients experienced an event: one had an adverse drug reaction, three had systemic progression of sepsis, and two had local progression. Two of the 21 patients died. No death was related to ICOAS or infection. There was no significant difference between the population with an event and the population free of an event with regard to demographic, clinical, and microbiological characteristics (p>0.05).

CONCLUSIONS

ICOAS appeared to be an effective and safe option in this cohort.

Management of Prosthetic Joint Infection

Although uncommon, prosthetic joint infection is a devastating complication. This challenging condition requires a coordinated management approach to achieve good patient outcomes. This review details the general principles to consider when managing patients with prosthetic joint infection. The different medical/surgical treatment strategies and how to appropriately select a strategy are discussed. The data to support each strategy are presented, along with discussion of antimicrobial strategies in specific situations.

Old antimicrobials and Gram-positive cocci through the example of infective endocarditis and bone and joint infections

The management of some serious infections such as infective endocarditis (IE) and bone and joint infections (BJIs) caused by Gram-positive cocci (GPC) is complex and requires great responsiveness and effective antimicrobials with high bioavailability in heart valves or bone tissues. Treatment of these infections requires the use of a higher dosage that may result in increased toxicity or the use of new promising antimicrobials to control the infection. However, use of these new antimicrobials could still bring about new toxicity and resistance. Another approach may be the 'comeback' of old antimicrobials, which is evaluated in this review in the treatment of IE and BJIs caused by GPC.

Efficacy of Antibiotic Suppressive Therapy in Patients with a Prosthetic Joint Infection

Introduction: For chronic prosthetic joint infections (PJI), complete removal of the infected prosthesis is necessary in order to cure the infection. Unfortunately, a subgroup of patients is not able to undergo a revision surgery due to high surgical risk. Alternatively, these patients can be treated with antibiotic suppressive therapy (AST) to suppress the infection. Aim: To evaluate the efficacy and tolerability of AST. Methods: We retrospectively collected data (period 2009-2015) from patients with a PJI (of hip, knee or shoulder) who were treated with AST at the University Medical Center Groningen, the Netherlands. AST was defined as antibiotic treatment for PJI that was started after the usual 3 months of antibiotic treatment. The time of follow-up was defined from the time point AST was started. Treatment was considered as failed, when the patient still experienced joint pain, when surgical intervention (debridement, removal, arthrodesis or amputation) was needed to control the infection and/or when death occurred due to the infection. Results: We included 21 patients with a median age of 67 years (range 21 - 88) and with a median follow-up of 21 months (range 3 - 81). Coagulase negative staphylococci (CNS) (n=6), S. aureus (n=6) and polymicrobial flora (n=4) were the most frequently found causative pathogens. Most patients with CNS and S. aureus were treated with minocycline (67%) and clindamycin (83%) as AST, respectively. Overall, treatment was successful in 67% of patients. Failure was due to persistent joint pain (n=1), surgical intervention because of an uncontrolled infection (n=3), and death due the infection (n=3). We observed a treatment success of 90% in patients with a 'standard' prosthesis (n=11), compared to only 50% in patients with a tumor-prosthesis (n=10). Also, treatment was successful in 83% of patients with a CNS as causative microorganism for the infection, compared to 50% in patients with a S. aureus. Patients who failed on AST had a higher ESR in comparison to patients with a successful treatment (mean 73 ± 25SD versus 32 ± 19SD mm/hour (p = 0.007), respectively. 43% of patients experienced side effects and led to a switch of antibiotic treatment or a dose adjustment in almost all of these patients. Conclusions: Removal of the implant remains first choice in patients with chronic PJI. However, AST is a reasonable alternative treatment option in a subgroup of patients with a PJI who are no candidate for revision surgery, in particular in patients with a 'standard' prosthesis and/or CNS as the causative micro-organism.

The DAIR (debridement, antibiotics and implant retention) procedure for infected total knee replacement - a literature review

Prosthetic joint infection (PJI) is a devastating complication in total knee arthroplasty (TKA) and third most common cause of revision of TKA with significant morbidity and surgical challenges. Treatment options include non-operative measures with long term antibiotic suppression, debridement and implant retention (DAIR), one- or two-stage revision arthroplasty, arthrodesis and amputation. Implant retention without infection is ideal and DAIR has been reported to have variable success rates depending on patient factors, duration of infection, infecting micro-organisms, choice of procedure, single or multiple debridement procedures, arthroscopic or open, antibiotic choice and duration of antibiotic use. We present a thorough literature review of DAIR for infected TKA. The important factors contributing to failure are presence of sinus, immunocompromised patient, delay between onset of infection and debridement procedure, Staphylococcal infection in particular Meticillin Resistant Staphylococcal aureus, multiple debridement procedures, retention of exchangeable components and short antibiotic duration. In conclusion DAIR can be successful procedure to eradicate infection in TKA in selective patients with factors contributing to failure taken into account.

A highly efficient, low-toxic, wide-spectrum antibacterial coating designed for 3D printed implants with tailorable release properties

A broad spectrum antibacterial coatings with tailorable release properties were developed for 3D printed implants.

Clinical Presentation, Risk Factors, and Outcomes of Hematogenous Prosthetic Joint Infection in Patients with Staphylococcus aureus Bacteremia

BACKGROUND

Staphylococcus aureus bacteremia is a life-threatening condition that may lead to metastatic infection, including prosthetic joint infection.

METHODS

To assess clinical factors associated with hematogenous prosthetic joint infection, we retrospectively reviewed all patients with a joint arthroplasty in place at the time of a first episode of S. aureus bacteremia over a 5-year period at our institution. Patients with postsurgical prosthetic joint infection without hematogenous prosthetic joint infection were excluded.

RESULTS

There were 85 patients (143 arthroplasties) with either no prosthetic joint infection (n = 50; 58.8%) or hematogenous prosthetic joint infection in at least one arthroplasty (n = 35; 41.2%). The odds of hematogenous prosthetic joint infection was significantly increased among patients with community-acquired S. aureus bacteremia (odds ratio [OR] 18.07; 95% confidence interval [CI] 2.64-infinity; P = .001), as compared with nosocomial S. aureus bacteremia, in which there were no patients with hematogenous prosthetic joint infection. After adjusting for S. aureus bacteremia classification, the presence of ≥3 joint arthroplasties in place was associated with a nearly ninefold increased odds of hematogenous prosthetic joint infection as compared with those with 1-2 joint arthroplasties in place (OR 8.55; 95% CI 1.44-95.71; P = .012). All but one joint with prosthetic joint infection demonstrated at least one clinical feature suggestive of infection. There were 4 additional S. aureus prosthetic joint infections diagnosed during a median of 3.4 years of follow-up post hospitalization for S. aureus bacteremia.

CONCLUSION

Prosthetic joint infection is frequent in patients with existing arthroplasties and concomitant S. aureus bacteremia, particularly with community-acquired S. aureus bacteremia and multiple prostheses. In contrast, occult S. aureus prosthetic joint infection without clinical features suggestive of prosthetic joint infection at the time of S. aureus bacteremia is rare.

Deep prosthetic joint infection: a qualitative study of the impact on patients and their experiences of revision surgery

OBJECTIVES

Around 1% of patients who have a hip replacement have deep prosthetic joint infection (PJI) afterwards. PJI is often treated with antibiotics plus a single revision operation (1-stage revision), or antibiotics plus a 2-stage revision process involving more than 1 operation. This study aimed to characterise the impact and experience of PJI and treatment on patients, including comparison of 1-stage with 2-stage revision treatment.

DESIGN

Qualitative semistructured interviews with patients who had undergone surgical revision treatment for PJI. Patients were interviewed between 2 weeks and 12 months postdischarge. Data were audio-recorded, transcribed, anonymised and analysed using a thematic approach, with 20% of transcripts double-coded.

SETTING

Patients from 5 National Health Service (NHS) orthopaedic departments treating PJI in England and Wales were interviewed in their homes (n=18) or at hospital (n=1).

PARTICIPANTS

19 patients participated (12 men, 7 women, age range 56-88 years, mean age 73.2 years).

RESULTS

Participants reported receiving between 1 and 15 revision operations after their primary joint replacement. Analysis indicated that participants made sense of their experience through reference to 3 key phases: the period of symptom onset, the treatment period and protracted recovery after treatment. By conceptualising their experience in this way, and through themes that emerged in these periods, they conveyed the ordeal that PJI represented. Finally, in light of the challenges of PJI, they described the need for support in all of these phases. 2-stage revision had greater impact on participants' mobility, and further burdens associated with additional complications.

CONCLUSIONS

Deep PJI impacted on all aspects of patients' lives. 2-stage revision had greater impact than 1-stage revision on participants' well-being because the time in between revision procedures meant long periods of immobility and related psychological distress. Participants expressed a need for more psychological and rehabilitative support during treatment and long-term recovery.

Prosthetic joint infection

Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided.

Peri-prosthetic infections. When to avoid surgery

Successful treatment of prosthetic joint infections often requires multiple surgical interventions and prolonged antibiotic therapy. However, in some specific situations surgical intervention can not be the treatment of choice. We refer to situations where there is no pain or impairment of the general conditions, involving patients, usually elderly, refusing surgery. In these cases we consider the conservative approach as an option.

Direct electric current treatment under physiologic saline conditions kills Staphylococcus epidermidis biofilms via electrolytic generation of hypochlorous acid

The purpose of this study was to investigate the mechanism by which a direct electrical current reduced the viability of Staphylococcus epidermidis biofilms in conjunction with ciprofloxacin at physiologic saline conditions meant to approximate those in an infected artificial joint. Biofilms grown in CDC biofilm reactors were exposed to current for 24 hours in 1/10^th strength tryptic soy broth containing 9 g/L total NaCl. Dose-dependent log reductions up to 6.7 log₁₀ CFU/cm² were observed with the application of direct current at all four levels (0.7 to 1.8 mA/cm²) both in the presence and absence of ciprofloxacin. There were no significant differences in log reductions for wells with ciprofloxacin compared to those without at the same current levels. When current exposures were repeated without biofilm or organics in the medium, significant generation of free chlorine was measured. Free chlorine doses equivalent to the 24 hour endpoint concentration for each current level were shown to mimic killing achieved by current application. Current exposure (1.8 mA/cm²) in medium lacking chloride and amended with sulfate, nitrate, or phosphate as alternative electrolytes produced diminished kills of 3, 2, and 0 log reduction, respectively. Direct current also killed Pseudomonas aeruginosa biofilms when NaCl was present. Together these results indicate that electrolysis reactions generating hypochlorous acid from chloride are likely a main contributor to the efficacy of direct current application. A physiologically relevant NaCl concentration is thus a critical parameter in experimental design if direct current is to be investigated for in vivo medical applications.

Prosthetic joint infections

Prosthetic joint infections represent a major therapeutic challenge for both healthcare providers and patients. This article reviews the predisposing factors, pathogenesis, microbiology, diagnosis, treatment, and prophylaxis of prosthetic joint infection. The most optimal management strategy should be identified on the basis of a number of considerations, including type and duration of infection, antimicrobial susceptibility of the infecting pathogen, condition of infected tissues and bone stock, patient wishes, and functional status.

Eight years experience in treatment of prosthetic joint infections at a teaching hospital in Central Taiwan

BACKGROUND/PURPOSE

Prosthetic joint infection (PJI) has become an important issue in the management of patients who receive prostheses. We compared the clinical outcomes of PJIs caused by Gram-negative bacteria (GN PJIs) and Gram-positive bacteria (GP PJIs).

METHODS

Patients with culture-proven PJIs admitted to China Medical University Hospital between March 2001 and March 2009 were included in this retrospective study.

RESULTS

Fifty-nine patients were diagnosed with PJI during the study period. Nineteen patients had GN PJIs (mean age: 68 years) and 40 had GP PJIs (mean age: 61 years). The most common comorbid condition was diabetes mellitus (23.7%) and the most common presentation was joint pain (79.7%). Staphylococcus aureus was the most common pathogen, whereas Klebsiella pneumoniae was the most common Gram-negative pathogen. The GN PJI group included more cases of hematogenous infection (36.8% vs. 20%; p < 0.001), showed a shorter interval between onset of infection symptoms and surgical intervention (median: 8 days vs. 21 days; p = 0.04), and required longer medical treatment (median: 259 days vs. 161 days; p = 0.04). In comparison with patients whose prostheses were eventually removed, patients whose prostheses were not removed had a shorter interval between onset of infection symptoms and surgical intervention (median: 6 days vs. 90 days; p = 0.004 and median: 6 days vs. 44 days; p = 0.04) in the GP PJI and GN PJI groups, respectively.

CONCLUSION

GN PJI was less common than GP PJI, but GN PJI was more complicated and required longer treatment. Prospective randomized clinical studies are needed to investigate whether prosthesis implantation should be reserved if the patient undergoes early surgical intervention for PJI.

Management and prevention of prosthetic joint infection

Prosthetic joint infection (PJI) is a serious complication of total joint arthroplasty (TJA) that can negatively affect functional status and quality of life. This article examines the epidemiology of PJI and reviews current diagnostic, treatment, and management strategies. Diagnosis can be challenging because presenting symptoms are often nonspecific and there is no simple gold standard diagnostic test. Successful treatment of PJI requires a combination of medical and surgical strategies. Given the devastating nature of PJI and the increasing numbers of TJAs performed, prevention efforts remain critical.