Background. Two-stage revision arthroplasty is the standard treatment for chronic hip and knee periprosthetic joint infections (PJI). Accurate diagnosis of persistent infections at 2nd stage using established biomarkers and diagnostic criteria is of paramount importance. This study aimed to evaluate the diagnostic value of synovial calprotectin and alpha-defensin, and compare established diagnostic criteria from the International Consensus Meeting (ICM 2018) and the European Bone and Joint Infection Society (EBJIS 2021) to determine persistent PJI at the 2nd stage of a two-stage revision arthroplasty. Methods. We retrospectively analyzed 97 patients who underwent 100 two-stage revisions (hip: 39, knee: 61). Synovial fluid samples were assessed for calprotectin and alpha-defensin levels. ICM 2018 and EBJIS 2021 were applied to all patients undergoing 2nd stage revision. Receiver operating characteristic (ROC) curves and Youden Index were utilized to determine optimal cut-off values, and correlations between biomarkers were evaluated. The microbiological spectrum was analyzed at 2nd stage and re-revision surgery. Results. Calprotectin levels showed a sensitivity of 66.7%, specificity of 32.9%, and accuracy of 38.0% in predicting septic failure. Alpha-defensin showed sensitivity of 28.6%, specificity of 87.8%, and accuracy of 79.2%. Significant correlations included: calprotectin with PMN% (r = 0.471, p = 0.05) and alpha-defensin with WBC (r = 0.830, p < 0.01) in the successful cohort. For septic re-revisions, calprotectin and alpha-defensin were highly correlated (r = 0.969, p < 0.01). ICM correctly diagnosed persistent PJI in 26.7%, while EBJIS diagnosed 24.2%. The microbial spectrum shifted from gram-positive to gram-negative bacteria between reimplantation and re-revision surgeries. Conclusion. Synovial calprotectin and alpha-defensin demonstrated limited accuracy in ruling out persistent PJI at reimplantation. The low sensitivity of current diagnostic criteria, combined with the observed shift in microbial spectrum, underscores the challenges in diagnosing persistent PJI during 2nd stage of a two-stage revisions arthroplasty

Aims

The optimum type of antibiotics and their administration route for treating Gram-negative (GN) periprosthetic joint infection (PJI) remain controversial. This study aimed to determine the GN bacterial species and antibacterial resistance rates related to clinical GN-PJI, and to determine the efficacy and safety of intra-articular (IA) antibiotic injection after one-stage revision in a GN pathogen-induced PJI rat model of total knee arthroplasty.

Aims

We aimed to determine the concentrations of synovial vancomycin and meropenem in patients treated by single-stage revision combined with intra-articular infusion following periprosthetic joint infection (PJI), thereby validating this drug delivery approach.

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This study investigated vancomycin-microbubbles (Vm-MBs) and meropenem (Mp)-MBs with ultrasound-targeted microbubble destruction (UTMD) to disrupt biofilms and improve bactericidal efficiency, providing a new and promising strategy for the treatment of device-related infections (DRIs).

Aims

This aim of this study was to analyze the detection rate of rare pathogens in bone and joint infections (BJIs) using metagenomic next-generation sequencing (mNGS), and the impact of mNGS on clinical diagnosis and treatment.

The June 2024 Trauma Roundup³⁶⁰ looks at: Skin antisepsis before surgical fixation of limb fractures; Comparative analysis of intramedullary nail versus plate fixation for fibula fracture in supination external rotation type IV ankle injury; Early weightbearing versus late weightbearing after intramedullary nailing for distal femoral fracture (AO/OTA 33) in elderly patients: a multicentre propensity-matched study; Long-term outcomes with spinal versus general anaesthesia for hip fracture surgery; Operative versus nonoperative management of unstable medial malleolus fractures: a randomized clinical trial; Impact of smoking status on fracture-related infection characteristics and outcomes; Reassessing empirical antimicrobial choices in fracture-related infections; Development and validation of the Nottingham Trauma Frailty Index (NTFI) for older trauma patients.

Aims

Gram-negative infections are associated with comorbid patients, but outcomes are less well understood. This study reviewed diagnosis, management, and treatment for a cohort treated in a tertiary spinal centre.

Aims

Biofilm infections are among the most challenging complications in orthopaedics, as bacteria within the biofilms are protected from the host immune system and many antibiotics. Halicin exhibits broad-spectrum activity against many planktonic bacteria, and previous studies have demonstrated that halicin is also effective against Staphylococcus aureus biofilms grown on polystyrene or polypropylene substrates. However, the effectiveness of many antibiotics can be substantially altered depending on which orthopaedically relevant substrates the biofilms grow. This study, therefore, evaluated the activity of halicin against less mature and more mature S. aureus biofilms grown on titanium alloy, cobalt-chrome, ultra-high molecular weight polyethylene (UHMWPE), devitalized muscle, or devitalized bone.

Aims

This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated.

Aims

A higher failure rate has been reported in haematogenous periprosthetic joint infection (PJI) compared to non-haematogenous PJI. The reason for this difference is unknown. We investigated the outcome of haematogenous and non-haematogenous PJI to analyze the risk factors for failure in both groups of patients.

Aim. Currently, gram-negative bacteria (GNB), including multidrug-resistant (MDR-GNB) pathogens, are gaining importance in the aetiology of prosthetic joint infection (PJI). To characterize the antimicrobial resistance patterns of Gram-negative bacteria (GNB) causing hip prosthetic joint infections in elderly patients treated at a Brazilian tertiary academic hospital. Method. This is a retrospective, cross-sectional study of patients over 60 years of age undergoing hip arthroplasty from 2018 to 2023 at a tertiary academic trauma, which were diagnosed with hip prosthetic joint infection. PJI diagnosed was based on EBJIS criteria, in which intraoperative tissue cultures identified the pathogens. Demographics, reason for arthroplasty, type of implant and susceptibility patterns using disk diffusion method were analysed. Results. Overall, among 17 elderly patients diagnosed with hip infected arthroplasty, 45 bacterial isolated were identified. Debridement, irrigation, antibiotic and implant retention (DAIR) procedures due to uncontrolled infection occurred in 47.0% (n=8/17), and five patients underwent more than two DAIR surgeries. Tissue cultures yielded eleven different bacterial species, with GNB accounted for 64.4% (n=29/45) of pathogens. Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Pseudomonas aeruginosa were identified in 34.5% (n=10/29), 17.25% (n=5/29), 13.8% (n=4/29), and 13.8% (n=4/29), respectively. In the resistance profile analysis, E. coli was most sensitive to antibiotics, whereas K. pneumoniae showed resistance rates higher than 70% for cephalosporins, carbapenems, and quinolones. All A. baumannii isolates were resistant to meropenem, and 80% of these isolates were resistant to amikacin. Conclusions. This study emphasizes the role of GNB in the microbiological profile of PJI among elderly patients at a tertiary hospital in a Brazilian centre. The present study portrays a worryingly higher rates of MDR-GNB, mainly to quinolones and cephalosporins resistance which have been the cornerstone of PJI antibiotic treatment. In addition, higher rates carbapenems and aminoglycosides resistance shows a threat to antibiotic treatment of PJI. More global studies need to be carried out to show a likely change in the microbial epidemiology of PJI

Aim. Antibacterial activity of coatings based on metal and metal oxide nanoparticles (NPs) often depends on materials and biotic targets resulting in a material-specific killing activity of selected Gram-positive and Gram-negative bacteria, including drug-resistant strains. In this perspective, the NPs loading amount, the relative elemental concentration inside the nanogranular building blocks and the deposition method are of paramount importance when the goal is to widen the antimicrobial spectrum, but at the same time to avoid high levels of metal content to limit undesired toxic effects. Aim of the present study was evaluation of the antimicrobial properties of two multielement nanogranular coatings composed of Titanium-Silver and Copper and of Magnesium-Silver and Copper. Method. Ti-Ag-Cu and Mg-Ag-Cu NPs were deposited on circular cover glasses (VWR) by Supersonic Cluster Beam Deposition. Biofilm-producer strains of Staphylococcus aureus (methicillin susceptible and resistant), Staphylococcus epidermidis (methicillin susceptible and resistant), Escherichia coli (fully susceptible and producer of extended spectrum beta lactamases), and Pseudomonas aeruginosa (susceptible and multidrug-resistant) were selected. The abilities of the selected strains to adhere, colonize and produce biofilm on the discs coated with Ti-Ag-Cu or Mg-Ag-Cu NPs were compared to uncoated circular cover glasses which were used as growth control. Cytotoxicity was also evaluated in order to assess the biocompatibility of the newly synthesized NPs. Results. In comparison to uncoated controls, both coatings showed significant anti-adhesive properties against S. aureus, S. epidermidis, and E. coli. Reduction in adhesion to Mg-Ag-Cu coated discs was observed also for P. aeruginosa isolates, although differences vs uncoated controls did not reach statistical significance. Biofilm formation was reduced on discs coated with Mg-Ag-Cu compared to Ti-Ag-Cu and, again, coatings had a milder effect on P. aeruginosa, probably due to its exceptional capability of attachment and matrix production. These results were confirmed by the evaluation of bacterial colonization on nanoparticles-coated discs by means of confocal laser scanning microscopy. A viability of 95.8% and 89.4% of cells cultured in the presence of Ti-Ag-Cu and Mg-Ag-Cu discs, respectively, when compared to negative controls was observed, thus excluding cytotoxic effects on eukaryotic cells. Conclusions. The newly synthesized Ti-Ag-Cu and Mg-Ag-Cu coatings are able to limit bacterial adhesion colonization and biofilm production, thus highlighting the safe use of multi-element families of NPs as new strategies against bacterial attachment to the surface of biomedical implants. However, further studies addressing activity against P. aeruginosa and including a wide number of isolates are warranted

Most patients treated at our clinical setting present during chronic osteomyelitis stage, which is anecdotally likely to be poly-microbial. Adults with poly-microbial infection have a predilection for gram-negative bacteria and anaerobes, a scenario that hypothetically leads to a higher morbidity of poly-microbial osteomyelitis following trauma. Our study looks into the epidemiology of poly-microbial osteomyelitis treated at our Tumour and Infection unit. Retrospective study of patients treated for osteomyelitis from 2016 to 2020. Records of eligible patients were retrieved for examination. Demographics such as age, sex and race were recorded. Clinical presentation, organisms cultured, including their anti-microbial sensitivities were documented. There were 63 participants in the study. 31 (49.21%) had mono-microbial osteomyelitis with 32 (50.79%) having poly-microbial osteomyelitis. Majority of the poly-microbial patients presented with a sinus (68.75%) mostly located in the tibia (50%). Multiple mixed pathogens (both gam-positive and gram-negative) were cultured in our patients and this comprised 71.21% of the total bacteria cultured. Staphylococcus Aureus was the commonest bacteria (30%) isolated, followed by Enterococcus faecalis (12%). The commonest gram-negative bacteriae cultured was Enterococcus cloacae (10%) followed by Acinetobacter baumannii (7%). Most enterobacteriacae species were sensitive to Ertapenem and Ceftazidime. A slightly higher incidence of poly-microbial osteomyelitis was found in our study than that reported in literature. Furthermore, our study demonstrated a wide variety of organisms found in poly-microbial osteomyelitis, with a large contribution made by gram-negative anaerobic rod-shaped bacteria

Aims

Osteoporosis is characterized by decreased trabecular bone volume, and microarchitectural deterioration in the medullary cavity. Interleukin-19 (IL-19), a member of the IL-10 family, is an anti-inflammatory cytokine produced primarily by macrophages. The aim of our study was to investigate the effect of IL-19 on osteoporosis.

Aims

The management of periprosthetic joint infection (PJI) remains a major challenge in orthopaedic surgery. In this study, we aimed to characterize the local bone microstructure and metabolism in a clinical cohort of patients with chronic PJI.

Aims

This study was designed to characterize the recurrence incidence and risk factors of antibiotic-loaded cement spacer (ALCS) for definitive bone defect treatment in limb osteomyelitis.

The implantation of endoprosthesis is a routine procedure in orthopaedics. Endoprosthesis are mainly manufactured from ceramics, polymers, metals or metal alloys. To ensure longevity of the implants they should be as biocompatible as possible and ideally have antibacterial properties, to avoid periprosthetic joint infections (PJI). Various antibacterial implant materials have been proposed, but have so far only been used sporadically in patients. PJI is one of the main risk factors for revision surgeries. The aim of the study was to identify novel implant coatings that both exhibit antibacterial properties whilst having optimal biocompatibility.

Six different novel implant coatings and surface modifications (EBM TiAl6V4, strontium, TiCuN, TiNbN, gentamicin phosphate (GP), gentamicin phosphate+cationic polymer (GP+CP)) were compared to standard CoCrMo-alloy. The coatings were further characterized with regard to the surface roughness. E. coli and S. capitis were cultured on the modified surfaces to investigate the antibacterial properties. To quantify bacterial proliferation the optical density (OD) was measured and viability was determined using colony forming units (CFU). Murine bone marrow derived macrophages (BMMs) were cultured on the surfaces and differentiated into osteoblasts to quantify the mineralisation using the alizarin red assay.

All novel coatings showed reduced bacterial proliferation and viability compared to standard CoCrMo-alloy. A significant reduction was observed for GP and GP+CP coated samples compared to CoCrMo (OD_GP,E.coli = 0.18±0.4; OD_GP+CP,E.coli = 0.13±0.3; p≤0.0002; N≥7-8). An increase in osteoblast-mediated mineralisation was observed on all surfaces tested compared to CoCrMo. Furthermore, GP and GP+CP coated samples showed a statistically significant increase (M_GP = 0.21±0.1; M_GP+CP = 0.25±0.2; p<0.0001; N≥3-6).

The preliminary data indicates that the gentamicin containing surfaces have the most effective antibacterial property and the highest osseointegrative capacity. The use of antibiotic coatings on prostheses could reduce the risk of PJI while being applied on osseointegrative implant surfaces.

Aims. Gram-negative periprosthetic joint infection (PJI) has been poorly studied despite its rapidly increasing incidence. Treatment with one-stage revision using intra-articular (IA) infusion of antibiotics may offer a reasonable alternative with a distinct advantage of providing a means of delivering the drug in high concentrations. Carbapenems are regarded as the last line of defense against severe Gram-negative or polymicrobial infection. This study presents the results of one-stage revision using intra-articular carbapenem infusion for treating Gram-negative PJI, and analyzes the characteristics of bacteria distribution and drug sensitivity. Methods. We retrospectively reviewed 32 patients (22 hips and 11 knees) who underwent single-stage revision combined with IA carbapenem infusion between November 2013 and March 2020. The IA and intravenous (IV) carbapenem infusions were administered for a single Gram-negative infection, and IV vancomycin combined with IA carbapenems and vancomycin was applied for polymicrobial infection including Gram-negative bacteria. The bacterial community distribution, drug sensitivity, infection control rate, functional recovery, and complications were evaluated. Reinfection or death caused by PJI was regarded as a treatment failure. Results. Gram-negative PJI was mainly caused by Escherichia coli (8/34), Enterobacter cloacae (7/34), and Klebsiella pneumoniae (5/34). Seven cases (7/32) involved polymicrobial PJIs. The resistance rates of penicillin, cephalosporin, quinolones, and sulfonamides were > 10%, and all penicillin and partial cephalosporins (first and second generation) were > 30%. Of 32 cases, treatment failed to eradicate infection in only three cases (9.4%), at a mean follow-up of 55.1 months (SD 25 to 90). The mean postoperative Harris Hip Score and Hospital for Special Surgery knee score at the most recent follow-up were 81 (62 to 91) and 79 (56 to 89), respectively. One patient developed a fistula, and another presented with a local rash on an infected joint. Conclusion. The use of IA carbapenem delivered alongside one-stage revision effectively controlled Gram-negative infection and obtained acceptable clinical outcomes with few complications. Notably, first- and second-generation cephalosporins and penicillin should be administrated with caution, due to a high incidence of resistance. Cite this article: Bone Joint J 2023;105-B(3):284–293

The December 2022 Research Roundup³⁶⁰ looks at: Halicin is effective against Staphylococcus aureus biofilms in vitro; Synovial fluid and serum neutrophil-to-lymphocyte ratio: useful in septic arthritis?; Transcutaneous oximetry and wound healing; Orthopaedic surgery causes gut microbiome dysbiosis and intestinal barrier dysfunction; Mortality in alcohol-related cirrhosis: a nationwide population-based cohort study; Self-reported resistance training is associated with better bone microarchitecture in vegan people.

Aims. There is a considerable challenge in treating bone infections and orthopaedic device-associated infection (ODAI), partly due to impaired penetration of systemically administrated antibiotics at the site of infection. This may be circumvented by local drug administration. Knowledge of the release kinetics from any carrier material is essential for proper application. Ceftriaxone shows a particular constant release from calcium sulphate (CaSO. 4. ) in vitro, and is particularly effective against streptococci and a large portion of Gram-negative bacteria. We present the clinical release kinetics of ceftriaxone-loaded CaSO. 4. applied locally to treat ODAI. Methods. A total of 30 operations with ceftriaxone-loaded CaSO. 4. had been performed in 28 patients. Ceftriaxone was applied as a single local antibiotic in 21 operations and combined with vancomycin in eight operations, and in an additional operation with vancomycin and amphotericin B. Sampling of wound fluid was performed from drains or aspirations. Ceftriaxone concentrations were measured by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Results. A total of 37 wound fluid concentrations from 16 operations performed in 14 patients were collected. The ceftriaxone concentrations remained approximately within a range of 100 to 200 mg/l up to three weeks. The median concentration was 108.9 mg/l (interquartile range 98.8 to 142.5) within the first ten days. No systemic adverse reactions were observed. Conclusion. Our study highlights new clinical data of locally administered ceftriaxone with CaSO. 4. as carrier material. The near-constant release of ceftriaxone from CaSO. 4. observed in vitro could be confirmed in vivo. The concentrations remained below known local toxicity thresholds. Cite this article: Bone Joint Res 2022;11(11):835–842