Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

[Standardized risk-based antibiotic prophylaxis and adhesive film dressing for the prevention of wound infection following cochlear implantation]

BACKGROUND

There is no consensus in the pertinent literature regarding the optimal antibiotic prophylaxis (AP) for cochlear implantation (CI). This study evaluates the implementation of standardized risk-based AP combined with application of an adhesive film dressing.

MATERIALS AND METHODS

All CI cases since September 2019 were retrospectively reviewed for postoperative wound complications. While all patients received preoperative AP with ceftriaxone, postoperative AP after CI in patients older than 7 years was no longer routinely performed in our clinic. Exceptions were made according to predefined criteria for an increased risk of infection. The wound was covered with a transparent adhesive polyurethane film.

RESULTS

In 72% of the 219 cases, we did not perform postoperative AP. The overall wound complication rate was 2.7% (in the groups with and without postoperative AP, 4.9% and 1.9%, respectively). Wound infection did not occur in any of the patients without postoperative AP older than 70 years (n = 32), with controlled diabetes mellitus (n = 19), or with reimplantation due to technical defect (n = 19). The film did not need to be changed until the suture material was removed.

CONCLUSION

Standardized risk-based AP can avoid prolonged administration of antibiotics in selected patients. The film dressing permits continual examination and sufficient wound protection.

Preventive strategies to reduce the rate of periprosthetic infections in total joint arthroplasty; a comprehensive review

The increasing frequency of total hip (THA) and knee arthroplasties (TKA) is marred by the rise in periprosthetic joint infections (PJIs) and surgical site infections (SSIs), with PJIs incurring costs over $1.62 billion as of 2020 and individual case management averaging $90,000. SSIs additionally burden the U.S. healthcare economy with billions in expenses annually. PJI prevalence in primary THA and TKA ranges from 0.5% to 2.4%, spiking to 20% in revisions and representing 25% of TKA revision causes. Projections estimate up to 270,000 annual PJI cases by 2030. Often caused by gram-positive bacteria, particularly methicillin-resistant staphylococci, these infections demand preventive measures. This review dissects PJI prevention across preoperative, intraoperative, and perioperative phases, aligning with evidence-based CDC and WHO guidelines. Preoperative measures include managing diabetes, obesity, tobacco use, Staphylococcus aureus screening and nasal decolonization, nutritional optimization, and management of inflammatory arthropathies. Intraoperatively, antibiotic prophylaxis, skin preparation, operative room environmental controls, surgical technique precision, and irrigation options are scrutinized. Perioperative concerns focus on anticoagulation, blood management, and infection risk mitigation. Integrating these strategies promotes a patient-centric care model, aiming to reduce PJI incidence, improve patient outcomes, and increase care cost-effectiveness in joint arthroplasty.

New strontium-based coatings show activity against pathogenic bacteria in spine infection

Infections of implants and prostheses represent relevant complications associated with the implantation of biomedical devices in spine surgery. Indeed, due to the length of the surgical procedures and the need to implant invasive devices, infections have high incidence, interfere with osseointegration, and are becoming increasingly difficult to threat with common therapies due to the acquisition of antibiotic resistance genes by pathogenic bacteria. The application of metal-substituted tricalcium phosphate coatings onto the biomedical devices is a promising strategy to simultaneously prevent bacterial infections and promote osseointegration/osseoinduction. Strontium-substituted tricalcium phosphate (Sr-TCP) is known to be an encouraging formulation with osseoinductive properties, but its antimicrobial potential is still unexplored. To this end, novel Sr-TCP coatings were manufactured by Ionized Jet Deposition technology and characterized for their physiochemical and morphological properties, cytotoxicity, and bioactivity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P human pathogenic strains. The coatings are nanostructured, as they are composed by aggregates with diameters from 90 nm up to 1 μm, and their morphology depends significantly on the deposition time. The Sr-TCP coatings did not exhibit any cytotoxic effects on human cell lines and provided an inhibitory effect on the planktonic growth of E. coli and S. aureus strains after 8 h of incubation. Furthermore, bacterial adhesion (after 4 h of exposure) and biofilm formation (after 24 h of cell growth) were significantly reduced when the strains were cultured on Sr-TCP compared to tricalcium phosphate only coatings. On Sr-TCP coatings, E. coli and S. aureus cells lost their organization in a biofilm-like structure and showed morphological alterations due to the toxic effect of the metal. These results demonstrate the stability and anti-adhesion/antibiofilm properties of IJD-manufactured Sr-TCP coatings, which represent potential candidates for future applications to prevent prostheses infections and to promote osteointegration/osteoinduction.

Differences Between Patients With Diabetes Mellitus and Obese Patients in Occurrence of Peri-Prosthetic Joint Infection: A Systemic Review and Meta-Analysis

Background: To understand the differences between patients with diabetes mellitus and obese patients with respect to the occurrence of peri-prosthetic joint infection (PJI) after lower-extremity joint arthroplasty as well as to identify differences in PJI occurrence at different time periods. Patients and Methods: The Cochrane Library, CINAHL, MEDLINE, and PubMed were searched for literature published between January 2000 and July 2022. Our targets were studies involving patients with PJI who had already been diagnosed as having diabetes mellitus or being obese before receiving lower-extremity joint arthroplasty. Analysis was performed using Comprehensive Meta-Analysis Software (CMA) Version 3 (Biostat, Inc., Englewood, NJ, USA). Results: A total of 53,522 patients with diabetes mellitus and 360,018 obese patients were included. The forest plot for patients with and without diabetes mellitus indicated that patients with diabetes mellitus were more likely to contract PJIs than were patients without diabetes mellitus (odds ratio, 1.84; 95% confidence interval [CI], 1.56-2.16) and that no differences existed among early, delayed, and late PJI occurrence in patients with diabetes mellitus. The forest plot for obese and non-obese patients indicated that obese patients were more likely to contract PJIs than were non-obese patients (odds ratio, 1.86; 95% CI, 1.53-2.14) and that among obese patients, early PJI occurrence was higher than was late PJI occurrence. In addition, the mixed model indicated that obese patients were more likely to develop early PJIs than were patients with diabetes mellitus. Conclusions: Patients with diabetes mellitus and obese patients were more likely to develop PJIs than were patients without diabetes mellitus and non-obese patients, and that obese patients were more likely to develop early PJIs than late PJIs. Also, obese patients were more likely to develop early PJIs than patients with diabetes mellitus.

10-Year Cumulative Incidence and Indications for Revision Total Knee Arthroplasty Among Patients Who Have Sickle Cell Disease

BACKGROUND

Literature regarding total knee arthroplasty (TKA) outcomes in sickle cell disease (SCD) is limited. Moreover, 10-year survivorship of SCD implants is unknown. This study aimed to observe 10-year cumulative incidence and indications for revision TKA in patients who did and did not have SCD.

METHODS

Patients who underwent primary TKA were identified using a large national database. The SCD patients were matched by age, sex, and a comorbidity index to a control cohort in a 1:4 ratio. The 10-year cumulative incidence rates were determined using Kaplan-Meier survival analyses. Multivariable analyses were conducted using Cox proportional hazard modeling. Chi-squared analyses were conducted to compare indications for revision between cohorts. In total, 1,010 SCD patients were identified, 100,000 patients included in the unmatched control, and 4,020 patients included in the matched control.

RESULTS

Compared to the unmatched control cohort, SCD patients exhibited higher 10-year all-cause revision (HR: 1.86; P < .001) with higher proportions of revisions for periprosthetic joint infection (PJI) (P < .001), aseptic loosening (P < .001), and hematoma (P < .001). Compared to the matched control, SCD patients had higher 10-year all-cause revision (Hazard Ratio (HR): 1.39; P = .034) with a higher proportion of revisions for PJI (P = .044), aseptic loosening (P = .003), and hematoma (P = .019).

CONCLUSION

Independent of other comorbidities, SCD patients are more likely to undergo revisions for PJI, aseptic loosening, and hematoma compared to patients who do not have SCD. Due to the high-risk of these complications, perioperative and postoperative surgical optimization should be enforced in SCD patients.

The Role of Single Positive Cultures in Presumed Aseptic Total Hip and Knee Revision Surgery-A Systematic Review of the Literature

(1) Background: Prior to revision hip (THA) or knee arthroplasty (TKA), periprosthetic low-grade infection (PJI) should be ruled out. Despite advances in preoperative diagnosis, unsuspected positive cultures (UPCs) may occur in initially planned aseptic revisions. Particularly, single UPCs pose a diagnostic and therapeutic dilemma, as their impact on outcome is unclear and recommendations are heterogeneous. This review investigates the frequency of single UPCs and their impact on implant survivorship. (2) Methods: In July 2022, a comprehensive literature search was performed using PubMed and Cochrane Library search. In total, 197 articles were screened. Seven retrospective studies with a total of 5821 cases were able to be included in this review. (3) Results: Based on the cases included, UPCs were found in 794/5821 cases (14%). In 530/794 cases (67%), the majority of the UPCs were single positive. The most commonly isolated pathogens were coagulase negative Staphylococci and Cutibacterium acnes. Five of seven studies reported no influence on revision- or infection-free survival following a single positive culture. In two studies, single UPCs following THA revision were correlated with subsequent re-revision for PJI. (4) Conclusions: Single UPCs of a non-virulent pathogen following presumed aseptic TKA revision may be interpreted as contaminants. A single UPC following THA revision may be a risk factor for subsequent PJI. The role of systemic antibiotic treatment remains unclear, but it should be considered if other risk factors for PJI are present.

Prevalence of modifiable risk factors in primary elective arthroplasty and their association with infections

BACKGROUND AND PURPOSE

The aim of this study was to identify the prevalence of modifiable risk factors of surgical site infections (SSI) in patients undergoing primary elective total joint arthroplasty (TJA) receiving conventional preoperative preparation, and to explore their association with infectious outcomes.

PATIENTS AND METHODS

Information regarding modifiable risk factors (anemia, diabetes, obesity, nutritional status, smoking, physical activity) was prospectively gathered in patients undergoing primary TJA of hip or knee in 2018-2020 at a single institution with 6 weeks' follow-up time.

RESULTS

738 patients (median age 68 years [IQR 61-73], women 57%) underwent TJA (knee 64%, hip 36%). Anemia was detected in 8%, diabetes was present in 9%, an additional 2% had undiagnosed diabetes (HbA1c > 47 mmol/mol), and 8% dysglycemia (HbA1c 42-47 mmol/mol). Obesity (BMI ≥ 30) was observed in 52%. Serum albumin, total lymphocyte count, and vitamin D below normal limits was identified in 0.1%, 18%, and 16%, respectively. Current smokers were 7%. Surgical site complications occurred in 116 (16%), superficial SSI in 57 (8%), progressing to periprosthetic joint infection in 7 cases. Univariate analysis identified higher odds of superficial SSI for BMI ≥ 30 (OR 2.1, 95%CI 1.2-3.8) and HbA1c ≥ 42 mmol/mol (OR 2.2, CI 1.1-4.2), but no association was found with other factors.

CONCLUSION

In a general population undergoing primary TJA an association was found between obesity (52%) and dysglycemia/diabetes (19%) and superficial SSI (8%), which progressed to PJI in 12% of cases, generating a 1% total rate of PJI. Modification of these risk factors might mitigate infectious adverse outcomes.

Easy and Affordable: A New Method for the Studying of Bacterial Biofilm Formation

BACKGROUND

Bacterial biofilm formation (BBF) proves itself to be in the spotlight of microbiology research due to the wide variety of infections that it can be associated with, the involvement in food spoilage, industrial biofouling and perhaps sewage treatment. However, BBF remains difficult to study due to the lack of standardization of the existing methods and the expensive equipment needed. We aim to describe a new inexpensive and easy to reproduce protocol for a 3D-printed microfluidic device that can be used to study BBF in a dynamic manner.

METHODS

We used the SolidWorks 3D CAD Software (EducationEdition 2019-2020, Dassault Systèmes, Vélizy-Villacoublay, France) to design the device and the Creality3D Ender 5 printer (Shenzhen Creality 3D Technology Co., Ltd., Shenzhen, China) for its manufacture. We cultivated strains of Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa. For the biofilm evaluation we used optical coherence tomography (OCT), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and crystal violet staining technique.

RESULTS

Based on the analysis, Enterococcus faecalis seems to produce more biofilm in the first hours while Pseudomonas aeruginosa started to take the lead on biofilm production after 24 h.

CONCLUSIONS

With an estimated cost around €0.1285 for one microfluidic device, a relatively inexpensive and easy alternative for the study of BBF was developed.

Sonication of revised hip and knee prostheses detects occult infections, improves clinical outcomes and prevents re - revisions. A case series study

Introduction

Periprosthetic joint infection (PJI) is a devastating complication occurring in 1–2% of primary and up to 10% of revised total hip and knee arthroplasties (THA and TKA) impairing patient's quality of life. Occult infections are underdiagnosed, sub-treated and sub-clinically experienced by patients. This study aimed to correlate patients' clinical outcomes with early antibiotic treatment based on use or non-use of a sonication technique on explanted prostheses.

Methods

33 patients with revised THA or TKA were retrospectively evaluated. Clinical outcomes were assessed via Oxford hip or knee scores, and correlated with administration or not of antibiotic treatment based on sonication results.

Results

According to laboratory findings the patients were divided in the following three groups: 1. Septic loosening (conventional cultures and/or sonication positive), 2. Aseptic loosening (conventional cultures and sonication negative) and 3. Occult loosening (conventional cultures negative, sonication not performed). The average Oxford score was poor (27.9/60) for the septic, excellent (43.8/60) for the aseptic and intermediate (37.7/60) for the occult group. Additionally, conventional cultures were negative, but sonication-positive, in 6 individuals with patient-related risk factors (male gender, BMI > 30 kg/m², diabetes, hypertension, steroids and rheumatoid arthritis).

Conclusions

Sonication represents a valuable diagnostic technique to guide administration of effective antibiotic treatment for patients, especially for detection of persistent post-revision occult infections. We recommend the systematic investigation of revised prostheses with a sonication technique, but especially in cases with risk factors for infection who it is suspected may have occult loosening.

Martins MC, Costa F. Antimicrobial Peptides in the Battle against Orthopedic Implant-Related Infections: A Review

Prevention of orthopedic implant-related infections is a major medical challenge, particularly due to the involvement of biofilm-encased and multidrug-resistant bacteria. Current therapies, based on antibiotic administration, have proven to be insufficient, and infection prevalence may rise due to the dissemination of antibiotic resistance. Antimicrobial peptides (AMPs) have attracted attention as promising substitutes of conventional antibiotics, owing to their broad-spectrum of activity, high efficacy at very low concentrations, and, importantly, low propensity for inducing resistance. The aim of this review is to offer an updated perspective of the development of AMPs-based preventive strategies for orthopedic and dental implant-related infections. In this regard, two major research strategies are herein addressed, namely (i) AMP-releasing systems from titanium-modified surfaces and from bone cements or beads; and (ii) AMP immobilization strategies used to graft AMPs onto titanium or other model surfaces with potential translation as coatings. In overview, releasing strategies have evolved to guarantee higher loadings, prolonged and targeted delivery periods upon infection. In addition, avant-garde self-assembling strategies or polymer brushes allowed higher immobilized peptide surface densities, overcoming bioavailability issues. Future research efforts should focus on the regulatory demands for pre-clinical and clinical validation towards clinical translation.

Bacterial profile and antimicrobial susceptibility patterns of isolates among patients diagnosed with surgical site infection at a tertiary teaching hospital in Ethiopia: a prospective cohort study

BACKGROUND

Globally, surgical site infections are the most reported healthcare-associated infection and common surgical complication. In developing countries such as Ethiopia, there is a paucity of published reports on the microbiologic profile and resistance patterns of an isolates.

OBJECTIVE

This study aimed at assessing the bacterial profile and antimicrobial susceptibility patterns of isolates among patients diagnosed with surgical site infection at Jimma Medical Center in Ethiopia.

METHODS

A prospective cohort study was employed among adult patients who underwent either elective or emergency surgical procedures. All the eligible patients were followed for 30 days for the occurrence of surgical site infection (SSI). From those who developed SSI, infected wound specimens were collected and studied bacteriologically.

RESULTS

Of 251 study participants, 126 (50.2%) of them were females. The mean ± SD age of the patients was 38 ± 16.30 years. The overall postoperative surgical site infection rate was 21.1% and of these 71.7% (38/53) were culture positive. On gram stain analysis, 78% of them were Gram-negative, 11.5% were Gram-positive and 10.5% were a mixture of two microbial growths. Escherichia coli accounted for (21.43%), followed by Pseudomonas aeruginosa (19.05%), Proteus species (spp.) 14.29%), Staphylococcus aureus (11.90%), Klebsiella species (11.90%), Citrobacter spp. (9.5%), streptococcal spp. (7.14%), Coagulase-negative S. aureus (CoNS) (2.38%) CONCLUSION: Gram-negative bacteria were the most dominant isolates from surgical sites in the study area. Among the Gram-negative bacilli, Escherichia coli were the most common bacteria causing surgical site infection. As there is high antibiotic resistance observed in the current study, it is necessary for routine microbial analysis of samples and their antibiogram.

A pragmatic eLCR for an ultrasensitive detection of methicillin-resistant Staphylococcus aureus in joint synovial fluid: superior to qPCR

For periprosthetic joint infection (PJI) patients, an early and rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) in joint synovial fluid is of great significance for receiving timely treatment and avoiding side effects. In clinical practice, the methods for detecting MRSA include the culture-based method and the PCR-based mecA gene detection method with fluorescent readout. However, the culture-based method requires up to 3-7 days for incubation and elaborative screening. The PCR-based molecular diagnosis, due to its high sensitivity, improves the detection time but sacrifices cost and gives false-positive results. Herein, a ligation chain reaction (LCR)-based electrochemical biosensor was developed to detect the mecA of MRSA with the advantages of rapidity, accuracy and low cost. In this system, an integrated dsDNA labeled with thiol and biotin at both terminals is generated only in the presence of the target DNA after LCR, followed by immobilization of the integrated dsDNAs on the bovine serum albumin (BSA)-coated gold electrode, and then the streptavidin horseradish peroxidase (SA-HRPs) is specifically bound to the biotin labels via biotin-streptavidin interaction, generating the catalytic amperometric readout. Impressively, the developed method achieved the detection of rare mecA in the joint synovial fluid of PJI patients (417-666 copies as quantified by qPCR). The proposed electrochemistry-based method is highly convenient for the point-of-care testing and was comparable with PCR in sensitivity, but superior in selectivity (single-base differentiation) and cost (nanomolar DNA probe consumption and simple device), demonstrating its huge potential in clinical applications for MRSA diagnosis.

Intraoperative Bacterial Contamination and Activity of Different Antimicrobial Prophylaxis Regimens in Primary Knee and Hip Replacement

Surgical antimicrobial prophylaxis (SAP) is important for the prevention of prosthetic joint infections (PJIs) and must be effective against the microorganisms most likely to contaminate the surgical site. Our aim was to compare different SAP regimens (cefazolin, cefuroxime, or vancomycin, alone or combined with gentamicin) in patients undergoing total knee (TKA) and hip (THA) arthroplasty. In this preclinical exploratory analysis, we analyzed the results of intraoperative sample cultures, the ratio of plasma antibiotic levels to the minimum inhibitory concentrations (MICs) for bacteria isolated at the surgical wound and ATCC strains, and serum bactericidal titers (SBT) against the same microorganisms. A total of 132 surgical procedures (68 TKA, 64 THA) in 128 patients were included. Cultures were positive in 57 (43.2%) procedures (mostly for coagulase-negative staphylococci and Cutibacterium spp.); the rate was lower in the group of patients receiving combination SAP (adjusted OR 0.475, CI95% 0.229-0.987). The SAP regimens evaluated achieved plasma levels above the MICs in almost all of intraoperative isolates (93/94, 98.9%) and showed bactericidal activity against all of them (SBT range 1:8-1:1024), although SBTs were higher in patients receiving cefazolin and gentamicin-containing regimens. The potential clinical relevance of these findings in the prevention of PJIs remains to be determined.