One hundred and twelve infected arthroplasties treated with 'DAIR' (debridement, antibiotics and implant retention): antibiotic duration and outcome

How to manage treatment failure in prosthetic joint infection

BACKGROUND

Management for prosthetic joint infections remains a challenging area for both infectious diseases and orthopaedic surgery, particularly in the setting of treatment failure. This is compounded by a lack of level 1 evidence to guide approaches. The optimal management of prosthetic joint infections requires a multi-disciplinary approach combined with shared decision making with the patient.

AIMS

This article describes the approach to prosthetic joint infections in the setting of treatment failure.

SOURCES

Narrative review based on literature review from PubMed. There was no time limit on the studies included. In addition, the reference list for included studies were reviewed for literature saturation with manual searching of clinical guidelines. Management approaches described incorporate evidence- and eminence-based recommendations from expert guidelines and clinical studies, where applicable.

CONTENT

The surgical and antimicrobial approaches for prosthetic joint infections are described for first-line treatment of prosthetic joint infections and approaches in the event of treatment failure. Management approaches are based on an understanding of the role the biofilm plays in the pathogenesis of prosthetic joint infections. The management of these infections aims to fulfil two key goals: to eradicate the biofilm-associated microorganisms and, to maintain a functional joint and quality of life. In treatment failure, these goals are not always feasible, and the role of the multi-disciplinary team and shared-decision making are prominent.

IMPLICATIONS

Prosthetic joint surgery is a high-volume surgery, and the demand for this surgery is continually increasing. With this, the number of infections requiring expert care will also increase. Eminence-based management approaches have been established to guide treatment failure until knowledge gaps in optimal management are addressed by well-designed, clinical trials.

Platelet-rich plasma lysate displays antibiofilm properties and restores antimicrobial activity against synovial fluid biofilms in vitro

Infectious arthritis is difficult to treat in both human and veterinary clinical practice. Recent literature reports Staphylococcus aureus as well as other gram-positive and gram-negative isolates forming free-floating biofilms in both human and equine synovial fluid that are tolerant to traditional antimicrobial therapy. Using an in vitro equine model, we investigated the ability of platelet-rich plasma (PRP) formulations to combat synovial fluid biofilm aggregates. Synovial fluid was infected, and biofilm aggregates allowed to form over a 2-hour period. PRP was collected and processed into different formulations by platelet concentration, leukocyte presence, and activation or lysis. Infected synovial fluid was treated with different PRP formulations with or without aminoglycoside cotreatment. Bacterial load (colony-forming unit/mL) was determined by serial dilutions and plate counting at 8 hours posttreatment. All PRP formulations displayed antimicrobial properties; however, formulations containing higher concentrations of platelets without leukocytes had increased antimicrobial activity. Lysis of PRP and pooling of the PRP lysate (PRP-L) from multiple horses as compared to individual horses further increased antimicrobial activity. This activity was lost with the removal of the plasma component or inhibition of the proteolytic activity within the plasma. Fractionation of pooled PRP-L identified the bioactive components to be cationic and low-molecular weight (<10 kDa). Overall, PRP-L exhibited synergism with amikacin against aminoglycoside tolerant biofilm aggregates with greater activity against gram-positive bacteria. In conclusion, the use of PRP-L has the potential to augment current antimicrobial treatment regimens which could lead to a decrease in morbidity and mortality associated with infectious arthritis.

Clinical Characteristics, Etiology, and Initial Management Strategy of Newly Diagnosed Periprosthetic Joint Infection: A Multicenter, Prospective Observational Cohort Study of 783 Patients

Background

Periprosthetic joint infection (PJI) is a devastating complication of joint replacement surgery. Most observational studies of PJI are retrospective or single-center, and reported management approaches and outcomes vary widely. We hypothesized that there would be substantial heterogeneity in PJI management and that most PJIs would present as late acute infections occurring as a consequence of bloodstream infections.

Methods

The Prosthetic joint Infection in Australia and New Zealand, Observational (PIANO) study is a prospective study at 27 hospitals. From July 2014 through December 2017, we enrolled all adults with a newly diagnosed PJI of a large joint. We collected data on demographics, microbiology, and surgical and antibiotic management over the first 3 months postpresentation.

Results

We enrolled 783 patients (427 knee, 323 hip, 25 shoulder, 6 elbow, and 2 ankle). The mode of presentation was late acute (>30 days postimplantation and <7 days of symptoms; 351, 45%), followed by early (≤30 days postimplantation; 196, 25%) and chronic (>30 days postimplantation with ≥30 days of symptoms; 148, 19%). Debridement, antibiotics, irrigation, and implant retention constituted the commonest initial management approach (565, 72%), but debridement was moderate or less in 142 (25%) and the polyethylene liner was not exchanged in 104 (23%).

Conclusions

In contrast to most studies, late acute infection was the most common mode of presentation, likely reflecting hematogenous seeding. Management was heterogeneous, reflecting the poor evidence base and the need for randomized controlled trials.

Longitudinal Model of Periprosthetic Joint Infection in the Rat

The majority of periprosthetic joint infections occur shortly after primary joint replacement (<3 months) and require the removal of all implant components for the treatment period (~4 months). A clinically relevant animal model of periprosthetic infection should, therefore, establish an infection with implant components in place. Here, we describe a joint replacement model in the rat with ultrahigh molecular weight polyethylene (UHMWPE) and titanium components inoculated at the time of surgery by methicillin-sensitive Staphylococcus aureus (S. aureus), which is one of the main causative microorganisms of periprosthetic joint infections. We monitored the animals for 4 weeks by measuring gait, weight-bearing symmetry, von Frey testing, and micro-CT as our primary endpoint analyses. We also assessed the infection ex vivo using colony counts on the implant surfaces and histology of the surrounding tissues. The results confirmed the presence of a local infection for 4 weeks with osteolysis, loosening of the implants, and clinical infection indicators such as redness, swelling, and increased temperature. The utility of specific gait analysis parameters, especially temporal symmetry, hindlimb duty factor imbalance, and phase dispersion was identified in this model for assessing the longitudinal progression of the infection, and these metrics correlated with weight-bearing asymmetry. We propose to use this model to study the efficacy of using different local delivery regimens of antimicrobials on addressing periprosthetic joint infections. Statement of clinical significance: We have established a preclinical joint surgery model, in which postoperative recovery can be monitored over a multi-week course by assessing gait, weight-bearing, and allodynia. This model can be used to study the efficacy of different combinations of implant materials and medication regimens. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1101-1112, 2020.

The difference between native septic arthritis and prosthetic joint infections: A review of literature

Current literature occasionally considers septic arthritis in native joints and prosthetic joint infections as equal pathologies. However, significant differences can be identified. The aim of this review of literature is to describe these differences in definitions, pathology, diagnostic workups, treatment strategies, and prognosis.

The Role of Long-Term Antibiotic Suppression in the Management of Peri-Prosthetic Joint Infections Treated With Debridement, Antibiotics, and Implant Retention: A Systematic Review

BACKGROUND

A number of clinical trials have been conducted, assessing the role of long-term (>1 year) suppressive antibiotic treatment (SAT) combined with Debridement, Antibiotics, and Implant Retention (DAIR) for the management of peri-prosthetic joint infection (PJI). However, no systematic review of the literature has been published to date to evaluate complications associated with long-term antibiotic treatment and overall survivorship free from re-operation and revision for infection after DAIR for total hip and total knee PJI.

METHODS

The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to December 2018 utilizing keywords pertinent to total knee arthroplasty, total hip arthroplasty, PJI, and antibiotic suppression.

RESULTS

Overall, 7 articles of low quality (level III or IV) were included in this analysis. The studies included in this systematic review included 437 cases of PJI treated surgically with DAIR and then with SAT. The overall mean infection-free rate of SAT following DAIR was 75% (318/424 patients), while the all-cause re-operation rate was 6.7%. Overall, the mean rate of adverse effects associated with long-term antibiotic use was 15.4% and the mean rate of adverse effects leading to discontinuation of SAT was 4.3%. There was no study to show significant differences between acute (either post-operative or hematogenous, with onset of symptoms ≤4 weeks) and chronic (onset of symptoms >4 weeks) infections and failure rates of DAIR with SAT. The literature is inconclusive on the influence of anatomic location (hip vs knee) as well as microorganism on the success rate of DAIR with SAT.

CONCLUSION

The results of this systematic review demonstrate that there is still only low-quality evidence regarding the therapeutic effect of DAIR combined with SAT, which is not enough to draw definitive conclusions. Furthermore, high-quality prospective studies are needed to better understand SAT's efficacy and safety in a controlled fashion. Although discontinuation of antibiotic treatment due to side effects was found to be low, the high rates of adverse effects noted after DAIR with SAT demonstrate the underlying frailty and complexity of many patients with PJI, and the imperfect therapies available. Although Staphylococcus aureus appears to be a risk factor for increased risk of SAT failure, there are not enough data to establish which patients would benefit most from DAIR with post-operative SAT.

Suppressive antibiotic therapy in prosthetic joint infections: a multicentre cohort study

OBJECTIVES

The aim was to describe the effectiveness of suppressive antibiotic treatment (SAT) in routine clinical practice when used in situations in which removal of a prosthetic implant is considered essential for the eradication of an infection, and it cannot be performed.

METHODS

This was a descriptive retrospective and multicentre cohort study of prosthetic joint infection (PJI) cases managed with SAT. SAT was considered to have failed if a fistula appeared or persisted, if debridement was necessary, if the prosthesis was removed due to persistence of the infection or if uncontrolled symptoms were present.

RESULTS

In total, 302 patients were analysed. Two hundred and three of these patients (67.2%) received monotherapy. The most commonly used drugs were tetracyclines (39.7% of patients) (120/302) and cotrimoxazole (35.4% of patients) (107/302). SAT was considered successful in 58.6% (177/302) of the patients (median time administered, 36.5 months; IQR 20.75-59.25). Infection was controlled in 50% of patients at 5 years according to Kaplan-Meier analysis. Resistance development was documented in 15 of 65 (23.1%) of the microbiologically documented cases. SAT failure was associated with age <70 years (sub-hazard ratio (SHR) 1.61, 95% CI 1.1-2.33), aetiology other than Gram-positive cocci (SHR 1.56, 95% CI 1.09-2.27) and location of the prosthesis in the upper limb (SHR 2.4, 95% CI 1.5-3.84). SAT suspension was necessary due to adverse effects in 17 of 302 patients (5.6%).

CONCLUSIONS

SAT offers acceptable results for patients with PJI when surgical treatment is not performed or when it fails to eradicate the infection.

Six-week antibiotic therapy after one-stage replacement arthroplasty for hip and knee periprosthetic joint infection

OBJECTIVES

One-stage replacement arthroplasty for treatment of periprosthetic joint infection (PJI) results in similar cure rate than two-stage (around 85-92%), but antibiotic therapy duration is not well established. The aim of this study was to evaluate the efficacy of a short six-week antibiotic course in periprosthetic joint infections after onstage exchange.

PATIENTS AND METHODS

Retrospective, observational study conducted at Orthopaedic Department of Cochin Hospital, Paris, between 1st January 2010 and 31 December 2015. Patients with a microbiologically proven PJI, treated with one-stage replacement and 6 weeks (+/1week) of antimicrobial therapy were included. Pearson's-χ² and Wilcoxon tests were used to compare categorical and continuous variables.

RESULTS

Fifty patients with periprosthetic joint infections (42 hip, 8 knee PJI) treated with one-stage replacement arthroplasty were included. Median age was 69.3 years (IQR 24.5-97.4). Infections occurred after a mean of 36 months (IQR 1-216). Bone biopsy cultures were positive for Staphylococcus spp. in 29 patients (58%), Cutibacterium acnes in 19 (38%), Gram-negative bacilli in 6 (12%). Polymicrobial infections occurred in 12 (24%). Intravenous antibiotics were administered for a median of 11 days (IQR 4-45) and 46 patients (92%) were switched to an oral therapy. Medium follow-up was of 32 months (IQR 12-101). Overall remission rate was 90%.

CONCLUSIONS

A six-week course of antibiotics in knee and hip PJIs treated with one-stage RA has a satisfactory remission rate in this open study.

The Use of Calcium Sulphate beads in Periprosthetic Joint Infection, a systematic review

Purpose: To assess the use of calcium sulphate (CS) beads in the management of knee and hip periprosthetic joint infections (PJI) in terms of outcomes, complications and re-infection rates.

Methods: A search of NICE healthcare database advanced search (HDAS) was conducted from its year of inception to October 2019 with the keywords: “Calcium Sulphate Beads” or “Calcium Sulfate Beads” or “Antibiotics beads” or “Stimulan” and “Arthroplasty” or “Hip Replacement” or “Knee Replacement” and “Periprothetic joint infection” or “Debridement, Antibiotics and implant retention” or “Revision”. A quality assessment was performed using the NIH study Quality Assessment Tool for case series.

Results: Out of relevant 74 articles, 5 articles met the inclusion criteria. Variable outcomes and success rates have been reported in most of the patients. A small number of wound discharges and heterotrophic ossification (HO) were reported, which are occasionally symptomatic. Hypercalcemia is identified as a potential risk with the use of CS beads especially with doses over 40 cc per operation. The influence of CS beads on reinfection rate is reported in 4 out of 5 articles. Due to the case-mix and heterogenicity of the patients involved and the causative microorganism reported as well as varied procedures are undertaken including one and two stages revision and Debridement, Antibiotics and implant retention (DAIR), the influence of CS beads varied from high success to poor outcome. The poor outcome is higher if the primary procedure for the management of hip and knee PJI is DAIR rather than full revision.

Conclusions: The use of CS beads in the treatment of PJI is a useful technique in delivering high doses of antibiotics locally. A favourable outcome is reported when antibiotics loaded CS is used as an adjuvant to revision procedure for PJI in hip and knee arthroplasty compared to its use as an adjuvant to DAIR procedure. There has been an increase in complications when higher volumes of beads are used, especially in subcutaneous structures and in high-risk patients. Another possible theoretical and unreported complication of CS beads is accelerating the wear rate in the artificial joint due to the possibility of causing abrasion to the bearing surfaces. The current evidence is not enough to indicate the superiority of antibiotic-loaded CS beads as an adjuvant for the treatment of PJI in Hip and Knee arthroplasty.

Short postsurgical antibiotic therapy for spinal infections: protocol of prospective, randomized, unblinded, noninferiority trials (SASI trials)

BACKGROUND

There are several open scientific questions regarding the optimal antibiotic treatment of spinal infections (SIs) with or without an implant. The duration of postsurgical antibiotic therapy is debated.

METHODS

We will perform two unblinded randomized controlled trials (RCTs). We hypothesize that shorter durations of systemic antibiotic therapy after surgery for SI are noninferior (10% margin, 80% power, α = 5%) to existing (long) treatment durations. The RCTs allocate the participants to two arms of 2 × 59 episodes each: 3 vs. 6 weeks of targeted postsurgical systemic antibiotic therapy for implant-free SIs or 6 vs. 12 weeks for implant-related SIs. This equals a total of 236 adult SI episodes (randomization scheme 1:1) with a minimal follow-up of 12 months. All participants receive concomitant multidisciplinary surgical, re-educational, internist, and infectious disease care. We will perform three interim analyses that are evaluated, in a blinded analysis, by an independent study data monitoring committee. Besides the primary outcome of remission, we will also assess adverse events of antibiotic therapy, changes of the patient's nutritional status, the influence of immune suppression, total costs, functional scores, and the timely evolution of the (surgical) wounds. We define infection as the presence of local signs of inflammation (pus, wound discharge, calor, and rubor) together with microbiological evidence of the same pathogen(s) in at least two intraoperative samples, and we define remission as the absence of clinical, laboratory, and/or radiological evidence of (former or new) infection.

DISCUSSION

Provided that there is adequate surgical debridement, both RCTs will potentially enable prescription of less antibiotics during the therapy of SI, with potentially less adverse events and reduced overall costs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04048304. Registered on 5 August 2019.

PROTOCOL VERSION

2, 5 July 2019.

Implant retention and high rate of treatment failure in hematogenous acute knee and hip prosthetic joint infections

OBJECTIVES

Only few studies evaluated hematogenous prosthetic joint infections. We aimed to describe the characteristics of these infections and factors associated with management failure.

METHODS

We selected hematogenously-acquired infections, defined by the occurrence of infectious symptoms more than a year after implantation among records of patients treated for hip and knee prosthetic joint infections at Montpellier University Hospital between January 2004 and May 2015. Failure was defined by death due to prosthesis-related infection, need for prosthesis removal in case of conservative treatment, or recurrence of infectious signs on a new prosthesis.

RESULTS

Forty-seven patients with hematogenous prosthetic joint infection were included (33 knee infections and 14 hip infections). Infectious agents were streptococci (43%), Staphylococcus aureus (43%), Gram-negative bacilli (13%), and Listeria monocytogenes (2%). Thirty-one patients were initially treated with debridement and implant retention and 15 with prosthesis removal (three with one-stage surgery, 10 with two-stage surgery). The median duration of antibiotic therapy was 66.5 days. The overall failure rate was 52% (24/48), 71% (22/31) with implant retention strategy, 13% (2/15) with prosthesis removal, and 63% (12/19) in case of Staphylococcus aureus infection. Conservative treatment was appropriate (arthrotomy on a well-implanted prosthesis without sinus tract and symptom onset <21 days) in 13/31 patients (42%) with a failure rate still high at 69% (9/13). The only factor associated with failure was conservative surgical treatment.

CONCLUSION

The high risk of failure of conservative treatment for hematogenous prosthetic joint infections should lead to considering prosthesis replacement as the optimal strategy, particularly with Staphylococcus aureus.

Early Debridement, antibiotics and implant retention (DAIR) in patients with suspected acute infection after hip or knee arthroplasty - safe, effective and without negative functional impact

Introduction: Debridement, antibiotics and implant retention (DAIR) is known to be effective in treating acute periprosthetic joint infection (PJI). However, deciding to perform additional surgery in the early postoperative period may be challenging as there is the concern of adding morbidity and clinical presentation is often subtle. We mean to assess the impact of early DAIR on final functional outcome. Methods: A case-control comparison was performed between patients that underwent DAIR for suspected PJI between 2010-2016 and controls randomly selected (1:2 ratio) from a list of primary joint replacements. Patients were matched for anatomic site, age, gender, American Society of Anesthesiologists (ASA) classification, body mass index and follow-up time. The outcome of surgical treatment and complications were assessed and Hip disability and Osteoarthritis Outcome Score (HOOS) or Knee injury and Osteoarthritis Outcome Score (KOOS) were performed. Results: Thirty-eight cases were included at a mean follow-up of 42 months. Infection was not confirmed in one patient. There was one infection related-death and three other cases of treatment failure that required a two-stage revision. Overall success rate was 89.2%. There were no significant patient reported differences regarding final functional outcome between both groups: pain 91±6 vs. 87±13; other symptoms 90±8 vs. 90±9; activities of day living 86±8 vs. 85±14; sport 63±13 vs. 57±16; quality of life 78±17 vs. 76±16. Discussion: These findings support that DAIR for suspected acute PJI is safe, effective and causes no impact on final functional results. Thus, a low threshold for assuming infection and subsequent DAIR may safely be adopted in the early postoperative period.

Positive Blood Cultures Decrease the Treatment Success in Acute Hematogenous Periprosthetic Joint Infection Treated With Debridement, Antibiotics, and Implant Retention

BACKGROUND

The influence of positive blood cultures on surgical outcome of acute hematogenous periprosthetic joint infection (PJI) treated by debridement, antibiotics, and implant retention (DAIR) remains unknown. This study evaluated the influence of positive blood cultures on the treatment success of DAIR in patients with acute hematogenous PJI.

METHODS

A retrospective chart review on 49 patients with blood culture data for acute hematogenous PJI was performed from 2005 to 2016 at a single institution. All patients were treated by DAIR and had a minimum follow-up of 1 year. Treatment success was defined by the Delphi criteria. Multivariate logistic regression analysis was performed to identify variables associated with positive blood culture and treatment success. Kaplan-Meier survivorship curves and log-rank tests were used for analysis.

RESULTS

Overall, 44.9% (22/49) of blood cultures obtained yielded positive growth. Elevated Elixhauser comorbidity index was a significant risk factor associated with positive blood (adjusted odds ratio [OR], 1.65; 95% confidence interval [CI], 1.13-2.40; P = .049). A positive blood culture was the only significant factor predicting treatment failure in acute hematogenous PJI (OR, 3.94; 95% CI, 1.18-13.1; P = .026) after adjusting for confounding variables. Kaplan-Meier survivorship for infection-free implant survivorship was 53.1% (95% CI, 38.3%-65.8%) at 1 year for all patients, 66.7% (95% CI, 45.7%-81.1%) for patients with negative blood cultures, and 36.4% (95% CI, 17.2%-55.7%) for patients with positive blood cultures (P = .037).

CONCLUSION

The presence of positive blood cultures is associated with decreased treatment success of DAIR for acute hematogenous PJI. Patients with more comorbidities may need to be treated more aggressively for a favorable outcome.

Chronic Osteomyelitis with Staphylococcus aureus Deformation in Submicron Canaliculi of Osteocytes: A Case Report

CASE

A patient presenting with an infected diabetic foot ulcer and Staphylococcus aureus chronic osteomyelitis was studied to validate the clinical importance of bacterial colonization of osteocytic-canalicular networks, as we recently reported in a mouse model. We utilized transmission electron microscopy to describe the deformation of S. aureus, from round cocci to rod-shaped bacteria, in the submicron osteocytic-canalicular networks of amputated bone tissue.

CONCLUSION

To our knowledge, this is the first evidence of S. aureus deformation and invasion of the osteocytic-canalicular system in human bone, which supports a new mechanism of persistence in the pathogenesis of chronic osteomyelitis.

Debridement, antibiotics, and implant retention for periprosthetic knee infections: a pooling analysis of 1266 cases

Background

The debridement, antibiotics, and implant retention (DAIR) procedure is an established therapeutic option for periprosthetic knee infections (PKI). However, the efficacy and the indication for this procedure are still controversial.

Methods

All the relevant literatures were systematically reviewed and analyzed. The present study aimed to assess the success rate of DAIR in the management of PKI, identify the factors associated with prognosis of DAIR, and establish a simple algorithm for predicting a high success rate of DAIR.

Results

Totally, 33 studies with 1266 cases were included. The overall success rate following DAIR in the management of PKI was 57.11%. In the subgroup analyses, the factors of “the time from symptoms to debridement was < 3 weeks” and “the bacterial species other than methicillin-resistant Staphylococcus aureus” significantly improved the success rate of DAIR and thus were defined as the major criteria. The statistically insignificant factors of “the open debridement and liner exchange” and “the comorbidity of rheumatoid arthritis” were set as the minor criteria. The success rate of DAIR for PKI meeting all the major criteria and no less than one minor criterion was 80.98%, which was significantly higher than the overall success rate of DAIR (p < 0.05).

Conclusion

PKI cases meeting two major criteria and no less than one minor criterion may confer a high success rate of DAIR. This simple algorithm may contribute to identifying the appropriate PKI patient for DAIR treatment and predicting the prognosis of DAIR.

Twenty common errors in the diagnosis and treatment of periprosthetic joint infection

Background

Misconceptions and errors in the management of periprosthetic joint infection (PJI) can compromise the treatment success. The goal of this paper is to systematically describe twenty common mistakes in the diagnosis and management of PJI, to help surgeons avoid these pitfalls.

Materials and methods

Common diagnostic and treatment errors are described, analyzed and interpreted.

Results

Diagnostic errors include the use of serum inflammatory biomarkers (such as C-reactive protein) to rule out PJI, incomplete evaluation of joint aspirate, and suboptimal microbiological procedures (such as using swabs or collection of insufficient number of periprosthetic samples). Further errors are missing possible sources of distant infection in hematogenous PJI or overreliance on suboptimal diagnostic criteria which can hinder or delay the diagnosis of PJI or mislabel infections as aseptic failure. Insufficient surgical treatment or inadequate antibiotic treatment are further reasons for treatment failure and emergence of antimicrobial resistance. Finally, wrong surgical indication, both underdebridement and overdebridement or failure to individualize treatment can jeopardize surgical results.

Conclusion

Multidisciplinary teamwork with infectious disease specialists and microbiologists in collaboration with orthopedic surgeons have a synergistic effect on the management of PJI. An awareness of the possible pitfalls can improve diagnosis and treatment results.

Evaluation One Year after DAIR Treatment in 91 Suspected Early Prosthetic Joint Infections in Primary Knee and Hip Arthroplasty

INTRODUCTION

Early recognition and appropriate initial treatment with debridement, antibiotics and implant retention (DAIR) if a suspicion of an early prosthetic joint infection (PJI) is present can eradicate infection on first attempt and prevent implant failure. We evaluated the outcome after 1 year of patients treated with DAIR after primary total knee arthroplasty (TKA) or total hip arthroplasty (THA). Furthermore, we determined preoperative, microbiology, and treatment factors related to failure after DAIR.

METHODS

A retrospective cohort study was assembled with 91 patients undergoing DAIR with a high suspicion of an early PJI. Records were reviewed for demographics, preoperative laboratory results, microbiological data, given treatment and postoperative follow-up. The primary outcome was infection-free implant survival at 1 year. Repeated DAIR was not considered as treatment failure.

RESULTS

The rate of infection-free implant survival following DAIR in a suspected early PJI was 85% (95% confidence intervals (CI) 78-91). Cultures remained negative in 20 patients, with no occurrence of infection during follow-up. A higher failure rate was seen in early PJI caused by Enterococcus faecalis (p=0.04). Multivariate analysis showed a statistically significant association between treatment failure and high C-reactive protein level (CRP >100) (odds ratio 10.0, 95% CI [1.5-70]) and multiple DAIR procedures (≥2) (odds ratio 5.0, 95%CI [1.1-23]).

CONCLUSION

If an early PJI is suspected DAIR is the appointed treatment with up to 2 debridement procedures. Since culture-negative DAIRs were not related to any complications during follow-up, overtreatment of suspected PJI seems to do no significant harm with respect to implant failure.

Life-long antimicrobial therapy: where is the evidence?

The decision to prescribe long-term or 'life-long' antibiotics in patients requires careful consideration by the treating clinician. While several guidelines exist to help assist in this decision, the long-term consequences are yet to be well studied. In this review, we aim to provide a summary of the available evidence for patient populations where long-term antibiotic therapy is currently recommended in clinical practice. We will also discuss the pitfalls of this approach, including medication adverse effects, economic cost and any possible contribution to the emerging epidemic of microbial resistance.

Impact of Bacterial Infections on Osteogenesis: Evidence From In Vivo Studies

The clinical impact of bacterial infections on bone regeneration has been incompletely quantified and documented. As a result, controversy exists about the optimal treatment strategy to maximize healing of a contaminated defect. Animal models are extremely useful in this respect, as they can elucidate how a bacterial burden influences quantitative healing of various types of defects relative to non-infected controls. Moreover, they may demonstrate how antibacterial treatment and/or bone grafting techniques facilitate the osteogenic response in the harsh environment of a bacterial infection. Finally, it a well-known contradiction that osteomyelitis is characterized by uncontrolled bone remodeling and bone loss, but at the same time, it can be associated with excessive new bone apposition. Animal studies can provide a better understanding of how osteolytic and osteogenic responses are related to each other during infection. This review discusses the in vivo impact of bacterial infection on osteogenesis by addressing the following questions (i) How does osteomyelitis affect the radiographic bone appearance? (ii) What is the influence of bacterial infection on histological bone healing? (iii) How do bacterial infections affect quantitative bone healing? (iv) What is the effect of antibacterial treatment on the healing outcome during infection? (v) What is the efficacy of osteoinductive proteins in infected bones? (vi) What is the balance between the osteoclastic and osteoblastic response during bacterial infections? (vii) What is the mechanism of the observed pro-osteogenic response as observed in osteomyelitis? © 2019 The Authors. Journal of Orthopaedic Research^© published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 37:2067-2076, 2019.

Prolonged suppressive antibiotic therapy is successful in the management of prosthetic joint infection

INTRODUCTION

Prosthetic joint infection (PJI) remains one of the major challenges facing orthopaedic surgeons. There is a paucity of evidence on non-operative management of PJI. We present the results of prolonged antibiotic suppression therapy (PSAT) in PJI from a single centre.

METHODS

A retrospective study was performed. Twenty-six patients were included. Two patients were excluded due to the lack of follow-up data. Failure was defined as admission for sepsis from the joint or amputation.

RESULTS

Average age was 72 years (range 35-93). Mean Charlson co-morbidity index was 4.3. Mean follow-up was 3.2 years (range 1.3-5.7). Staphylococcal species were isolated in 11 cases (44%) (MRSA 1, MSSA 5, Staph. epidermidis 4 and Staph Pasteuri 1). Other bacteria included E. Coli (2), Streptococci spp. (3), Propionebacterium acnes (1) and Pseudomonas aeruginosa (1). Four cases were polymicrobial infection (16%), and no organisms were identified in two cases (8%). Candida albicans was identified in one case. All cases of bacterial infection were treated with prolonged oral doxycycline or amoxicillin. Twenty patients (80%) received 6 weeks of intravenous antibiotics prior to commencing prolonged oral antibiotics. Two patients experienced persistent symptoms and required amputation (both TKA). Two patients experienced sepsis but were treated successfully with IV antibiotics alone. The success rate of PSAT was 84% (21/25) successful at an average 3.2-year follow-up.

DISCUSSION AND CONCLUSION

Prolonged suppressive antibiotic therapy is a viable option for the management of PJI with a low incidence of complications.

Debridement, Antibiotics and Implant Retention for Early Periprosthetic Infections of the Hip: Outcomes and Influencing Factors

Purpose

Debridement, antibiotics and implant retention (DAIR) is commonly performed and widely accepted for the treatment of acute infections following hip arthroplasty. The aims of this study were to: i) determine the DAIR success rate in treating acute postoperative and hematogenous periprosthetic infections of the hip at a tertiary hospital, ii) identify possible outcome predictors, and iii) analyze clinical and radiological outcomes.

Materials and Methods

We retrospectively reviewed cases of acute postoperative (≤3 months from index procedure) and hematogenous periprosthetic infections following total hip arthroplasty treated with DAIR at our hospital between 2004 and 2015. Overall, 26 hips (25 patients) were included in the study, with a mean age of 72.5 years (standard deviation [SD], 9.4). The mean follow-up was 48.5 months (SD, 43.7). Several variables (e.g., patient characteristics, infection type, surgery parameters) were examined to evaluate their influence on outcomes; functional and radiographic outcomes were assessed.

Results

The overall success rate of DAIR was 26.9%. The male sex was associated with treatment failure (P=0.005) and debridement performed by a surgeon in hip unit with success (P=0.028). DAIR failure increased in patients with chronic pulmonary disease (P=0.059) and steroid therapy (P=0.062). Symptom duration of <11 days until DAIR yielded a better infection eradication rate (P=0.068). The mean postoperative Harris Hip Score was 74.2 (SD, 16.6).

Conclusion

DAIR, despite being used frequently, had a high failure rate in our series. Outcomes improved if an experienced hip arthroplasty surgeon performed the surgery. Patient comorbidities and symptom duration should be considered for decision-making.

The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces

Purpose: Bacterial biofilms are a major problem in the treatment of infected dental and orthopedic implants. The purpose of this study is to investigate the cleaning effect of an electrolytic approach (EC) compared to a powder-spray system (PSS) on titanium surfaces. Materials and Methods: The tested implants (different surfaces and alloys) were collated into six groups and treated ether with EC or PSS. After a mature biofilm was established, the implants were treated, immersed in a nutritional solution, and streaked on Columbia agar. Colony-forming units (CFUs) were counted after breeding and testing (EC), and control (PSS) groups were compared using a paired sample t-test. Results: No bacterial growth was observed in the EC groups. After thinning to 1:1,000,000, 258.1 ± 19.9 (group 2), 264.4 ± 36.5 (group 4), and 245.3 ± 40.7 (group 6) CFUs could be counted in the PSS groups. The difference between the electrolytic approach (test groups 1, 3, and 5) and PSS (control groups 2, 4, and 6) was statistically extremely significant (p-value < 2.2 × 10⁻¹⁶). Conclusion: Only EC inactivated the bacterial biofilm, and PSS left reproducible bacteria behind. Within the limits of this in vitro test, clinical relevance could be demonstrated.

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.

Linezolid in the treatment of periprosthetic joint infection caused by coagulase-negative staphylococci

Background: Periprosthetic joint infection (PJI) caused by coagulase-negative staphylococci (CoNS) is increasingly common and is sometimes treated with off-label use of linezolid. Methods: We conducted a retrospective study of patients with PJI caused by CoNS treated with surgical intervention and orally administrated linezolid during the period 1995-2014 (n = 28). Clinical outcomes and adverse events related to linezolid administration were evaluated. Mean time to follow-up was 4.3 years (range: 0.2-12). Results: Twenty-two of 28 patients were infection-free at follow-up. No CoNS strain was resistant to vancomycin, but 16 of 28 were resistant to rifampicin, 23 of 28 to clindamycin and 20 of 27 to quinolones. The mean duration of linezolid treatment was 4.2 weeks (range: 1-12). Eleven of 28 patients had an adverse event related to the antimicrobial treatment, and four had to discontinue linezolid, but all adverse events were reversible within 2 months after discontinuation. Conclusions: Oral linezolid administration combined with adequate surgical treatment may be useful for the treatment of PJIs caused by CoNS.

Irrigation, Débridement, and Implant Retention for Recurrence of Periprosthetic Joint Infection Following Two-Stage Revision Total Knee Arthroplasty: A Matched Cohort Study

BACKGROUND

We investigated clinical/functional outcomes and implant survivorship in patients who underwent 2-stage revision total knee arthroplasty (TKA) after periprosthetic joint infection (PJI), experienced acute PJI recurrence, and underwent irrigation, débridement, and polyethylene exchange (IDPE) with retention of stable implant.

METHODS

Twenty-four patients (24 knees) were identified who underwent 2-stage revision TKA for PJI, experienced acute PJI recurrence, and then underwent IDPE between 2005 and 2016 (minimum 2-year follow-up). After IDPE, intravenous antibiotics (6 weeks) and oral suppression therapy (minimum 6 months) were administered. Data were compared with 1:2 matched control group that underwent 2-stage revision TKA for chronic PJI and did not receive IDPE.

RESULTS

Average IDPE group follow-up was 3.8 years (range, 2.4-7.2). Reinfection rate after IDPE was 29% (n = 7): 3 of 7 underwent second IDPE (2 of 3 had no infection recurrence) and 5 (one was patient who had recurrent infection after second IDPE) underwent another 2-stage revision TKA. Control group reinfection rate was 27% (n = 13) (P = .85). For IDPE group, mean time to reinfection after 2-stage revision TKA was 4.6 months (range, 1-8 months) (patients presented with acute symptoms less than 3 weeks duration). At latest follow-up, mean Knee Society Score was 70 (range, 35-85) in IDPE group and 75 (range, 30-85) in control group (P = .53).

CONCLUSION

IDPE for acute reinfection following 2-stage revision TKA with well-fixed implants had a 71% success rate. These patients had comparable functional outcome as patients with no IDPE after 2-stage revision TKA. IDPE followed by long-term suppression antibiotic therapy should be considered in patients with acute infection and stable components.

Oral versus intravenous antibiotics for bone and joint infections: the OVIVA non-inferiority RCT

BACKGROUND

Management of bone and joint infection commonly includes 4-6 weeks of intravenous (IV) antibiotics, but there is little evidence to suggest that oral (PO) therapy results in worse outcomes.

OBJECTIVE

To determine whether or not PO antibiotics are non-inferior to IV antibiotics in treating bone and joint infection.

DESIGN

Parallel-group, randomised (1 : 1), open-label, non-inferiority trial. The non-inferiority margin was 7.5%.

SETTING

Twenty-six NHS hospitals.

PARTICIPANTS

Adults with a clinical diagnosis of bone, joint or orthopaedic metalware-associated infection who would ordinarily receive at least 6 weeks of antibiotics, and who had received ≤ 7 days of IV therapy from definitive surgery (or start of planned curative treatment in patients managed non-operatively).

INTERVENTIONS

Participants were centrally computer-randomised to PO or IV antibiotics to complete the first 6 weeks of therapy. Follow-on PO therapy was permitted in either arm.

MAIN OUTCOME MEASURE

The primary outcome was the proportion of participants experiencing treatment failure within 1 year. An associated cost-effectiveness evaluation assessed health resource use and quality-of-life data.

RESULTS

Out of 1054 participants (527 in each arm), end-point data were available for 1015 (96.30%) participants. Treatment failure was identified in 141 out of 1015 (13.89%) participants: 74 out of 506 (14.62%) and 67 out of 509 (13.16%) of those participants randomised to IV and PO therapy, respectively. In the intention-to-treat analysis, using multiple imputation to include all participants, the imputed risk difference between PO and IV therapy for definitive treatment failure was -1.38% (90% confidence interval -4.94% to 2.19%), thus meeting the non-inferiority criterion. A complete-case analysis, a per-protocol analysis and sensitivity analyses for missing data each confirmed this result. With the exception of IV catheter complications [49/523 (9.37%) in the IV arm vs. 5/523 (0.96%) in the PO arm)], there was no significant difference between the two arms in the incidence of serious adverse events. PO therapy was highly cost-effective, yielding a saving of £2740 per patient without any significant difference in quality-adjusted life-years between the two arms of the trial.

LIMITATIONS

The OVIVA (Oral Versus IntraVenous Antibiotics) trial was an open-label trial, but bias was limited by assessing all potential end points by a blinded adjudication committee. The population was heterogenous, which facilitated generalisability but limited the statistical power of subgroup analyses. Participants were only followed up for 1 year so differences in late recurrence cannot be excluded.

CONCLUSIONS

PO antibiotic therapy is non-inferior to IV therapy when used during the first 6 weeks in the treatment for bone and joint infection, as assessed by definitive treatment failure within 1 year of randomisation. These findings challenge the current standard of care and provide an opportunity to realise significant benefits for patients, antimicrobial stewardship and the health economy.

FUTURE WORK

Further work is required to define the optimal total duration of therapy for bone and joint infection in the context of specific surgical interventions. Currently, wide variation in clinical practice suggests significant redundancy that likely contributes to the excess and unnecessary use of antibiotics.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN91566927.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 38. See the NIHR Journals Library website for further project information.

Outcomes of Superficial and Deep Irrigation and Debridement in Total Hip and Knee Arthroplasty

BACKGROUND

Following total knee arthroplasty and total hip arthroplasty, wound-related problems and deep periprosthetic joint infection may present in a similar fashion. Irrigation and debridement (I&D) has a great role in management of patients with early infection. The question that often arises is how to tell the difference between superficial and deep infection. This study evaluated the role and outcomes of both superficial and deep I&D in patients with wound-related issues and/or suspected periprosthetic joint infection.

METHODS

A retrospective study was conducted evaluating patients who underwent I&D within 28 days of total joint arthroplasty. A total of 176 cases with a minimum of 1-year follow-up were identified, and clinical records were reviewed in detail. Reoperations included superficial (fascia not opened) or deep (fascia opened) I&D. Failure was defined as the need for further surgical intervention within 1 year of initial I&D.

RESULTS

The overall success for superficial I&D was 84.28% vs 68.86% for deep I&D. The success of both deep and superficial I&D was higher if the I&D was performed closer to the index surgery. Superficial I&D in patients with a positive joint aspiration or evidence of intraoperative purulence or those in whom had no subcutaneous fluid had higher failure rates.

CONCLUSION

Superficial I&D is a viable option in patients with wound-related issues as long as joint aspiration is performed to rule out infection involving the prosthesis. If there are findings of no fluid or purulence, fascia may need to be opened and the deeper tissues explored.

The prognosis of streptococcal prosthetic bone and joint infections depends on surgical management-A multicenter retrospective study

BACKGROUND

The optimal treatment of streptococcal prosthetic joint infections (PJIs) is unclear.

METHODS

A cohort of streptococcal PJIs was reviewed retrospectively in seven reference centers for the management of complex bone and joint infections, covering the period January 1, 2010 to December 31, 2012.

RESULTS

Seventy patients with monomicrobial infections were included: 47 had infections of total hip arthroplasty and 23 had infections of total knee arthroplasty. The median age was 77 years (interquartile range (IQR) 69-83 years), the median Charlson comorbidity score was 4 (IQR 3-6), and 15.6% (n=11) had diabetes. The most commonly identified streptococcal species were Streptococcus agalactiae and Streptococcus dysgalactiae (38.6% (n=27) and 17.1% (n=12), respectively). Debridement, antibiotics and implant retention (DAIR) was performed after a median time of 7 days (IQR 3-8 days), with polyethylene exchange (PE) in 21% of cases. After a minimum follow-up of 2 years, 27% of patients had relapsed, corresponding to 51.4% of DAIR treatment cases and 0% of one-stage (n=15) or two-stage (n=17) exchange strategy cases. Rifampicin or levofloxacin in combination therapy was not associated with a better outcome (adjusted p= 0.99). S. agalactiae species and DAIR treatment were associated with a higher risk of failure. On multivariate analysis, only DAIR treatment and S. agalactiae were independent factors of relapse. Compared to DAIR without PE, DAIR with PE was only associated with a trend towards a benefit (odds ratio 0.33, 95% confidence interval 0.06-1.96; adjusted p= 0.44).

CONCLUSIONS

Streptococcal PJIs managed with DAIR have a poor prognosis and S. agalactiae seems to be an independent factor of treatment failure.

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.

Iatrogenic wounds: a common but often overlooked problem

Iatrogenic wounds are a common but often overlooked concept. They can lead to increases in hospital stays, therapy costs, repeat surgeries, and implant removal. If not handled properly, these wounds have a very poor prognosis and will cause serious physical and psychological harm to patients, which may result in medicolegal disputes. In recent years, the incidence of iatrogenic wounds has increased because of (1) an increase in the population of older people owing to increased life expectancy, (2) the continued expansion of surgical indications, (3) an increase in difficult surgeries, and (4) the constant emergence and application of new implantable biomaterials and other therapies. Thus, there is a pressing clinical need to improve the therapy of iatrogenic wounds. However, the difficulty in treating these wounds is considerable due to the emergence of drug-resistant bacteria, the high number of patients with metabolic diseases, and complex complications in patients. In particular, iatrogenic wounds caused by surgical site infections due to implantable biomaterials could lead to material leakage and conflicts regarding whether to retain or remove the implants. This review provides a definition of iatrogenic wounds, describes their characteristics, classifies them, and provides information about the importance of analyzing iatrogenic wounds. We hope that this review will provide useful information for the diagnosis and treatment of iatrogenic wounds and help to reduce their incidence in the future.

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.

Bone transport with a unilateral external fixator for femoral infected nonunion after intramedullary nailing fixation: A case control study

This is a therapeutic study to evaluate the results of femoral infected nonunion using bone transport with an external fixator after debridement and irrigation. We retrospectively reviewed 15 patients with femoral infected nonunion after intramedullary nailing fixation of fractures from October 1999 to January 2010 in our institute. There were 7 males and 8 females with an average age of 32.5 years. First, the infection was eradicated completely, and the medullary canals were continuous irrigated for 2-3 weeks. After eradicating the infection tissues, the mean amount of bone defect was 8.7 cm (range, 4.0-16.0 cm). The unilateral consecutive distraction-compression osteosynthesis technique was applied after long-time medullary cavity-wound exclusion surgery. Enumeration data was described by frequency and measurement data by mean. Bone infections were controlled in all patients except 1 patient after the first debridement and irrigation. All patients have achieved bony union without recurrence of infection during the follow-up period, the mean external fixation index was 43.4 day/cm. According to the criteria recommended by Paley, the bone results were graded as excellent in 13 (86.7%) cases and good in 2 (13.3%) cases; the functional results were graded as excellent in 6 (40.0%) cases, good in 6 (40.0%) cases and fair in 3 (20.0%) cases. In management of femoral infectious nonunion which caused by intramedullary nailing fixation, the surgery of consecutive compression-distraction osteogenesis with unilateral external fixator achieves a highly effective treatment, and the method of debridement and irrigation is a compatible choice on the phase of infection-elimination.

Increased Failure After Irrigation and Debridement for Acute Hematogenous Periprosthetic Joint Infection

BACKGROUND

Acute periprosthetic joint infection (PJI) is difficult to treat. In this study, we investigated the failure rates of irrigation and debridement (I&D) among patients with acute post-surgical and acute hematogenous PJI, and explored various host and organism-related risk factors that may be associated with treatment failure.

METHODS

We retrospectively reviewed the cases of 199 total joint arthroplasty patients who underwent I&D for acute post-surgical PJI (<3 months postoperatively) and acute hematogenous PJI (≥3 months postoperatively, with abrupt symptoms lasting <3 weeks) at a single center during the period of 2005 to 2016. Only patients meeting the Musculoskeletal Infection Society (MSIS) criteria for PJI were included. Patient demographics, comorbidities, physical examination findings, laboratory results, and organism profile were identified. Treatment failure, as defined by the Delphi criteria, was determined for 1-year follow-up. Primary statistical analysis involved univariate and multivariate regression.

RESULTS

The failure rate was 37.7% (75 of 199) at 1 year. Among the patients with acute hematogenous infections, the rate of failure (56%, 29 of 52) was almost 2 times higher than that of patients with acute post-surgical infections (31%, 46 of 147) (adjusted odds ratio [OR], 2.36; 95% confidence interval [CI], 1.16 to 4.81; p = 0.018). Host predictors of failure included prior revision surgery (adjusted OR, 2.55; 95% CI, 1.22 to 5.32; p = 0.013) and a higher Charlson Comorbidity Index (adjusted OR, 1.22; 95% CI, 1.01 to 1.51; p = 0.048). Specific comorbidities associated with failure included chronic obstructive pulmonary disease (p = 0.026), diabetes (p = 0.004), and a history of malignancy (p = 0.005). Patients with polymicrobial infections (adjusted OR, 2.40; 95% CI, 1.10 to 5.20; p = 0.028) were also more likely to experience failure of treatment after I&D. The clinical and laboratory risk factors associated with failure were the presence of intraoperative purulence (p = 0.05), elevated systolic blood pressure (p = 0.05), tachycardia (p = 0.06), and higher serum C-reactive protein level (p = 0.003).

CONCLUSIONS

This study revealed that I&D is associated with a high rate of failure for patients with an acute hematogenous PJI. The study also identified a number of risk factors for failure. The findings of this study may allow better decision-making by surgeons regarding the surgical management of patients with acute PJI.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

[Clinical research of debridement with prosthesis retention for periprosthetic joint infection after arthroplasty]

Objective

To investigate the mid-term effectiveness of debridement with prosthesis retention for periprosthetic joint infection (PJI) after total hip arthroplasty (THA) and total knee arthroplasty (TKA), and analyze the influence factors that affected the effectiveness.

Methods

A clinical data of 45 cases with PJI after THA (16 cases) and TKA (29 cases) that were treated with debridement with prosthesis retention between January 2011 and January 2015 were collected and analyzed. There were 19 males and 26 females with a mean age of 58.4 years (range, 23-78 years). PJI occurred after primary joint arthroplasty in 40 cases and after revision in 5 cases. The mean time interval between the performance of infection symptoms and the arthroplasty or revision was 15.5 months (range, 0.5-72.0 months). The time interval between the performance of infection symptoms and debridment was 35 days (range, 3-270 days). There were early postoperative infections in 13 cases, acute hematogenous infections in 24 cases, and late chronic infections in 8 cases. X-ray films showed that the location of prosthesis was good. The results of bacilli culture showed that 28 cases were positive and 17 were negative. Twelve cases had sinuses. Length of stay, Hospital for Special Surgery (HSS) score, and Harris score were recorded to evaluate risk factors by using a multivariate logistic regression.

Results

The mean length of stay was 22.6 days (range, 5-79 days). All patients were followed up 24-74 months (mean, 52 months). There were 33 cases that retained the prosthesis without further evidence of infection with the success rate was 73.3%. There were significant differences in Harris score and HSS score between pre- and post-operation ( P<0.05). The univariate analysis results showed that the failure of debridement with prosthesis retention had a significant correlation with sinus developing and duration of infection symptoms more than 14 days ( P<0.05). Multivariate logistic regression analysis results showed that sinus developing was an independent risk factor of failure ( P<0.05).

Conclusion

Debridement with prosthesis retention plays an important role in treating PJI after THA and TKA. These patients with sinus performing and duration of infection symptoms more than 14 days have higher risk to develop infection again.

A standardized interdisciplinary algorithm for the treatment of prosthetic joint infections

AIMS

In 2013, we introduced a specialized, centralized, and interdisciplinary team in our institution that applied a standardized diagnostic and treatment algorithm for the management of prosthetic joint infections (PJIs). The hypothesis for this study was that the outcome of treatment would be improved using this approach.

PATIENTS AND METHODS

In a retrospective analysis with a standard postoperative follow-up, 95 patients with a PJI of the hip and knee who were treated with a two-stage exchange between 2013 and 2017 formed the study group. A historical cohort of 86 patients treated between 2009 and 2011 not according to the standardized protocol served as a control group. The success of treatment was defined according to the Delphi criteria in a two-year follow-up.

RESULTS

Patients in the study group had a significantly higher Charlson Comorbidity Index (3.9 vs 3.1; p = 0.009) and rate of previous revisions for infection (52.6% vs 36%; p = 0.025), and tended to be older (69.0 vs 66.2 years; p = 0.075) with a broader polymicrobial spectrum (47.3% vs 33.7%; p = 0.062). The rate of recurrent infection (3.1% vs 10.4%; p = 0.048) and the mean time interval between the two stages of the procedure (66.6 vs 80.7 days; p < 0.001) were reduced significantly in the study group compared with the control group.

CONCLUSION

We were able to show that the outcome following the treatment of PJIs of the hip and knee is better when managed in a separate department with an interdisciplinary team using a standard algorithm.

Role of Rifampin against Staphylococcal Biofilm Infections In Vitro, in Animal Models, and in Orthopedic-Device-Related Infections

Rifampin has been used as an agent in combination therapy in orthopedic device-related infections (ODRI) for almost three decades. The aim of this review is to provide data regarding the role of rifampin against biofilm infection in vitro, in animal models, and in clinical ODRI. Available data are gathered in order to present the rational use of rifampin combinations in patients with periprosthetic joint infection (PJI). The role of rifampin is well defined in patients with PJI and is indicated in those who fulfill the Infectious Diseases Society of America criteria for debridement and implant retention or one-stage exchange. It should be used with care because of the danger of rapid emergence of resistance. Potential drug interactions should be considered.

Curcumin nanoparticles are a promising anti-bacterial and anti-inflammatory agent for treating periprosthetic joint infections

Background

Periprosthetic joint infections (PJIs) have a high incidence of recurrence after total joint replacement and are difficult to treat by debridement or antibiotic treatment. Curcumin is a natural product with anti-inflammatory and anti-bacterial properties. The low bioactivity of curcumin in water restricts its clinical application. Curcumin nanoparticles (CURN) were developed to overcome this limitation.

Methods

In this study, the therapeutic effects of CURN and their anti-inflammatory functions were investigated in a Staphylococcus aureus biofilm-induced PJIs model.

Results

CURN first attenuated the biofilm-induced expansion of myeloid-derived suppressor cells (MDSCs) and then regulated M1- and M2-phenotypic MDSC expression. Down-regulation of cytokines and reactive oxygen species was considered as the mechanism of CURN in reversing the suppression of T cell proliferation. The recovery of bone permeative destruction demonstrated that CURN enhanced therapeutic potency of vancomycin in vivo.

Conclusion

This is the first study to demonstrate that CURN may be useful for treating PJIs.

Debridement, antibiotics and implant retention for periprosthetic joint infections: A systematic review and meta-analysis of treatment outcomes

OBJECTIVES

We aimed to assess infection control rates after DAIR in patients with periprosthetic joint infection (PJI) following joint arthroplasty and evaluate factors associated with infection control using a systematic review and meta-analysis.

METHODS

We searched MEDLINE, EMBASE, Web of Science, Cochrane databases and reference lists of relevant studies up to May 2017. Longitudinal studies conducted in patients with PJI treated exclusively by DAIR were eligible. Infection control rates were meta-analysed using random-effect models after arcsine transformation.

RESULTS

We included 93 articles based on 99 unique observational studies with data on 4897 PJIs treated by DAIR. The infection control rate for DAIR ranged from 11.1% to 100% with an overall pooled estimate of 61.4% (95% CI, 57.3-65.4) and a 95% prediction interval of 25.5% to 91.8%. Infection control rates remained generally similar for several relevant characteristics, except for evidence of variation by age, geographical location, type of infection and joint affected, duration of parenteral antibiotic therapy after the DAIR procedure, and period (year) of DAIR procedure.

CONCLUSIONS

The DAIR approach remains an option for the treatment of PJI as it is associated with acceptable infection control rates, particularly in acute postoperative infections and infections of the hip and shoulder joints.