Aim. Orthopedic implants play a tremendous role in fixing bone damages due to aging as well as fractures. However, these implants tend to get colonized by bacteria on the surface, leading to infections and subsequently prevention of healing and osteointegration. Recently, Roupie et al. showed that a nisin layer-by-layer based coating applied on biomaterials has both osteogenic and antibacterial properties. The Galleria mellonella larva is a well-known insect infection model that has been used to test the virulence of bacterial and fungal strains as well as for the high throughput screening of antimicrobial compounds against infections. Recently, we have developed an insect infection model with G. mellonella larvae to study implant-associated biofilm infections using Kirschner (K)-wires as implant material. Here, we would like to test the antibacterial capacity of nisin layer-by-layer based coatings on K-wires against Staphylococcus aureus in the G. mellonella larva
Aim. Antibiotic prophylaxis is central in preventing postoperative spine infections, yet knowledge of clinical spine tissue antibiotic concentrations remains limited. Pooled postoperative spine infection rates are constant (approximately 3%), resulting in severe patient morbidity, mortality, and prolonged hospitalization. Current antibiotic dosing regimens often involve fixed doses based on empirical knowledge, surrogate measures (plasma samples), non-clinical evidence (experimental models), and inferior methodology (tissue specimens). Therefore, personalized antibiotic dosing may be the future of antibiotic prophylaxis to prevent postoperative
Aim. Prosthetic joint infections (PJI) remain a great challenge in orthopedic surgery with a high mortality rate. It is particularly complicated by biofilms and infections caused by Methicillin-resistant Staphylococcus aureus (MRSA). It concurrently shields bacteria from host immune responses and confers resistance to antibiotics. This study aims to investigate the efficacy of radioimmunotherapy as an innovative therapeutic modality to address the challenges posed by MRSA and its biofilm. Method. We induced specific monoclonal antibodies 4497-IgG1 as carriers, which target wall teichoic acids (WTA) existing on MRSA and its biofilm. Radionuclides actiniumr-225 (. 225. Ac, α-emitter) and lutetium-177 (. 177. Lu, β-emitter) were conjugated with mAbs using DOTA as chelator. Quality control was assessed using thin layer chromatography and immunoreactivity assays. . 225. Ac- and . 177. Lu-labelled 4497-IgG1 were employed to evaluate the susceptibility of MRSA and its biofilm to the radioimmunotherapy in vitro. Planktonic MRSA and biofilms, at concentrations of 10. 8. and 10. 7. CFU/mL, were incubated at 37°C for 60 minutes in PBS containing either . 225. Ac-mAb (0 - 14.8 kBq) or . 177. Lu-mAb (0 - 14.8 MBq). Radiolabelled dunituximab and free radionuclides serve as isotype-matched negative control. The bacterial viability and metabolic activity were subsequently quantified using CFU and XTT assays. Results. The radiochemical purity of the . 225. Ac-mAbs and . 177. Lu-mAbs complex were determined to be 95.4% and 96.16%. Immunoreactivity fractions of them were measured at 81.8% and 80.8%. . 225. Ac-mAbs and . 177. Lu-mAbs exhibited significant and dose-dependent antimicrobial effects on both planktonic MRSA and biofilm. . 225. Ac- and . 177. Lu-4497IgG1 at doses of 7.4 kBq and 7.4 MBq resulted in more than 4-log reduction in bacterial counts. In biofilms, 2-log reduction at the highest . 225. Ac radioactivity of 14,8kBq. The . 177. Lu complex showed a strong dose-dependent effect, with a reduction of up to 4-log. The XTT assay confirmed these findings, showing a decrease in metabolic activity corresponding to a decrease in bacterial counts, and a slight increase in metabolic activity at the lower dose. Conclusions. Our study demonstrates the efficacy of . 225. Ac and . 177. Lu-labelled 4497-IgG1 antibodies in mediating dose-dependent bactericidal effects against planktonic MRSA and biofilms in vitro. This indicates that radioimmunotherapy could be a potential targeted therapeutic strategy against MRSA and its biofilm. Further research in preclinical and clinical settings is warranted to validate and refine these findings on biofilm-associated
Aim. Candida species are uncommon pathogens causing prosthetic joint infection (PJI). This study evaluated the surgical management and outcome of Candida PJI. Methods. Patients with EBJIS Definition confirmed PJI, due to Candida species, from 19 medical centres were assessed. Demographic, diagnostic, medical and surgical treatment and outcome data were collected. Results. 269 patients were recruited with follow-up for at least one year. Mean age was 70.2 years (+/- 12.4) with 10.8% being immunocompromised. The most common fungal species were C. albicans (55.8%), C. parapsilosis (29.4%), C. glabrata (7.8%) and C. tropicalis (5.6%). Co-infection with bacteria occurred in 138 (51.3%) cases. DAIR was performed in 96 (36.2%) cases, with 169 (63.8%) having implant exchange or removal (76 one-stage, 78 two-stage, 11 removal/Girdlestone arthroplasty, 2 amputation). Patient demographics and antifungal therapy were similar in all surgical groups. Overall, treatment was successful in 156 (58%) cases. Failure was more likely in older patients (>70 years; p=0.008) and those who had DAIR (OR 1.945; 1.156-3.279; p=0.004). Failure was less likely with C. parapsilosis infection compared to C. albicans (31.6% vs 48%; p=0.037). DAIR patients had more co-infection with bacteria (63.5% vs 47.4%; p=0.013) and more previous surgeries (median 4 vs 3; p=0.007), but multivariate analysis showed that these were not independent risk factors for failure. There was no difference in mortality between DAIR patients and those with other surgery (13.5% vs 17.7%; p=0.372). DAIR was successful in 45/96 (46.9%) cases compared to 110/169 (65.1%) cases with other surgery (p<0.004). Early DAIR (surgery performed <I month from
High doses of intra-articular (IA) antibiotics has been shown to effectively achieve a minimal biofilm eradication concentration which could mitigate the need for removal of infected but well-ingrown cementless components of a total hip arthroplasty (THA). However, there are concerns that percutaneous catheters could lead to multi-resistance or multi-organism peri-prosthetic joint infections (PJI) following single stage THA revisions for PJI. Eighteen single-stage revision procedures were performed for acute (N=9) or chronic (N=9) PJI following a primary (N=12) or revision (N=6) cementless THA. Modular and loosened components were replaced. All well ingrown components were retained. Two Hickmann catheters were placed in the joint space. Along with intravenous antibiotics, IA antibiotics were injected twice a day for two weeks, followed by 3 months of oral antibiotics. Per-operative cultures demonstrated 4 multi-bacterial PJIs. None of the patients developed post-operatively an AB related renal or systemic dysfunction. At a mean follow-up of 38 months [range, 8–72] all patients had normal erythrocyte sedimentation rate and white blood cell count. Four had a slightly elevated C-reactive protein but were completely symptom free and did not show any sign of loosening at a mean of 27 months [range, 16–59]. Addition of high doses of IA antibiotics following single-stage revision for PJI in cementless THA, is an effective and safe treatment option that allows for retention of well-ingrown components. We found no evidence for residual
Aims. Bacteriophages infect, replicate inside bacteria, and are released from the host through lysis. Here, we evaluate the effects of repetitive doses of the Staphylococcus aureus phage 191219 and gentamicin against haematogenous and early-stage biofilm implant-related infections in Galleria mellonella. Methods. For the haematogenous infection, G. mellonella larvae were implanted with a Kirschner wire (K-wire), infected with S. aureus, and subsequently phages and/or gentamicin were administered. For the early-stage biofilm
The number of revision arthroplasties being performed in the elderly is expected to rise, including revision for infection. The primary aim of this study was to measure the treatment success rate for octogenarians undergoing revision total hip arthroplasty (THA) for periprosthetic joint infection (PJI) compared to a younger cohort. Secondary outcomes were complications and mortality. Patients undergoing one- or two-stage revision of a primary THA for PJI between January 2008 and January 2021 were identified. Age, sex, BMI, American Society of Anesthesiologists grade, Charlson Comorbidity Index (CCI), McPherson systemic host grade, and causative organism were collated for all patients. PJI was classified as ‘confirmed’, ‘likely’, or ‘unlikely’ according to the 2021 European Bone and Joint Infection Society criteria. Primary outcomes were complications, reoperation, re-revision, and successful treatment of PJI. A total of 37 patients aged 80 years or older and 120 patients aged under 80 years were identified. The octogenarian group had a significantly lower BMI and significantly higher CCI and McPherson systemic host grades compared to the younger cohort.Aims
Methods
Aims. Delayed postoperative inoculation of orthopaedic implants with persistent wound drainage or bacterial seeding of a haematoma can result in periprosthetic joint infection (PJI). The aim of this in vivo study was to compare the efficacy of vancomycin powder with vancomycin-eluting calcium sulphate beads in preventing PJI due to delayed inoculation. Methods. A mouse model of PJI of the knee was used. Mice were randomized into groups with intervention at the time of surgery (postoperative day (POD) 0): a sterile control (SC; n = 6); infected control (IC; n = 15); systemic vancomycin (SV; n = 9); vancomycin powder (VP; n = 21); and vancomycin bead (VB; n = 19) groups. Delayed inoculation was introduced during an arthrotomy on POD 7 with 1 × 10. 5. colony-forming units (CFUs) of a bioluminescent strain of Staphylococcus aureus. The bacterial burden was monitored using bioluminescence in vivo. All mice were killed on POD 21. Implants and soft-tissue were harvested and sonicated for analysis of the CFUs. Results. The mean in vivo bioluminescence in the VB group was significantly lower on POD 8 and POD 10 compared with the other groups. There was a significant 1.3-log. 10. (95%) and 1.5-log. 10. (97%) reduction in mean soft-tissue CFUs in the VB group compared with the VP and IC groups (3.6 × 10. 3. vs 7.0 × 10. 4. ; p = 0.022; 3.6 × 10. 3. vs 1.0 × 10. 5. ; p = 0.007, respectively) at POD 21. There was a significant 1.6-log. 10. (98%) reduction in mean implant CFUs in the VB group compared with the IC group (1.3 × 10. 0. vs 4.7 × 10. 1. , respectively; p = 0.038). Combined soft-tissue and
The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery. A total of 454 consecutive patients who underwent cementless TKA between August 2004 and December 2021 were reviewed. The mean follow-up was ten years. Plain radiographs were analyzed for radiolucent lines. Patients who underwent revision TKA were recorded, and the cause for revision was determined. Data from the National Joint Registry for England, Wales, Northern Island, the Isle of Man and the States of Guernsey (NJR) were compared with our series.Aims
Methods
Total hip arthroplasty (THA) is a common procedure to address pain and enhance function in hip disorders such as osteoarthritis. Despite its success, postoperative patient recovery exhibits considerable heterogeneity. This study aimed to investigate whether patients follow distinct pain trajectories following THA and identify the patient characteristics linked to suboptimal trajectories. This retrospective cohort study analyzed THA patients at a large academic centre (NYU Langone Orthopedic Hospital, New York, USA) from January 2018 to January 2023, who completed the Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity questionnaires, collected preoperatively at one-, three-, six-, 12-, and 24-month follow-up times. Growth mixture modelling (GMM) was used to model the trajectories. Optimal model fit was determined by Bayesian information criterion (BIC), Vuong-Lo-Mendell-Rubin likelihood ratio test (VLMR-LRT), posterior probabilities, and entropy values. Association between trajectory groups and patient characteristics were measured by multinomial logistic regression using the three-step approach.Aims
Methods
To investigate the efficacy of ethylenediaminetetraacetic acid-normal saline (EDTA-NS) in dispersing biofilms and reducing bacterial infections. EDTA-NS solutions were irrigated at different durations (1, 5, 10, and 30 minutes) and concentrations (1, 2, 5, 10, and 50 mM) to disrupt Aims
Methods
The Global Burden of Disease Study 2019 showed a 33.4% increase in fractures and a 65.3% increase in Years lived with disability (YLD) since 1990. Although the overall rate of fracture related infection (FRI) is low, it increases to 30% in complex fractures. In addition, the implantation of foreign materials, such as fracture stabilizing implants, decreases the number of bacteria needed to cause an infection. Then, when infections do occur, they are difficult to treat and often require multiple surgeries to heal. The bacteria can persist in the canaliculi of the bony tissue, in cells, in a biofilm on material or necrotic bone or in abscess communities. In the last decades, different approaches have been pursued to modify biomaterials as well as implant surface and to develop antimicrobial surfaces or local drug release strategies. This talk will give an introduction to the problem of bony and
In orthopedic surgery,
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. Episodes of knee or hip PJI (defined by the European Bone and Joint Infection Society criteria) treated at our institution between January 2015 and October 2020 were included in a retrospective PJI cohort. Episodes with a follow-up of > one year were stratified by route of infection into haematogenous and non-haematogenous PJI. Probability of failure-free survival was estimated using the Kaplan-Meier method, and compared between groups using log-rank test. Univariate and multivariate analysis was applied to assess risk factors for failure.Aims
Methods
Aim. The use of medical devices has grown significantly over the last decades, and has become a major part of modern medicine and our daily life.
Aim. Dalbavancin is a lipoglycopeptide with a half-life of 14 days (range 6.1 to 18.4), significantly longer than other antimicrobials, which avoids the need for daily antibiotic dosing. This multi-centre observational study aims to describe the use of dalbavancin to facilitate discharge in treating bone and joint infections. Method. All adult patients treated with dalbavancin from January 2017 to September 2022 in four UK bone infection units were included. Data collected through a standardised data collection form included:. Clinical and microbiological characteristics. Hospital length of stay. Complications. Patient suitability for hypothetical treatment options, such as Outpatient Parenteral. Antibiotic Team (OPAT). Clinical outcome. Treatment-related costs were calculated for dalbavancin and the preferred hypothetical treatment option that would have been administered for the same duration. The costs were subtracted to calculate the cost difference. Clinical success was defined as the absence of definite failure in accordance with the OVIVA Trial protocol. Results. Thirty-six patients were included: 20 males and 16 females, with a median age of 53 (IQR 43–73): Thirteen were septic arthritis, twelve were prosthetic joints, seven were spondylodiscitis and five were other orthopaedic-related
Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date. Patients treated for IPOS from January 2006 to December 2020 were included. Patient demographics, parameters upon admission and discharge, radiological imaging, and microbiological results were retrieved from medical records. CT and MRI were analyzed for epidural, paravertebral, and intervertebral abscess formation, vertebral destruction, and endplate involvement. Pathogens were identified by CT-guided or intraoperative biopsy, intraoperative tissue sampling, or implant sonication.Aims
Methods
Several different designs of hemiarthroplasty are used to treat intracapsular fractures of the proximal femur, with large variations in costs. No clinical benefit of modular over monoblock designs has been reported in the literature. Long-term data are lacking. The aim of this study was to report the ten-year implant survival of commonly used designs of hemiarthroplasty. Patients recorded by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) between 1 September 1999 and 31 December 2020 who underwent hemiarthroplasty for the treatment of a hip fracture with the following implants were included: a cemented monoblock Exeter Trauma Stem (ETS), cemented Exeter V40 with a bipolar head, a monoblock Thompsons prosthesis (Cobalt/Chromium or Titanium), and an Exeter V40 with a Unitrax head. Overall and age-defined cumulative revision rates were compared over the ten years following surgery.Aims
Methods