Background. Meticillin-resistant Staphylococcus aureus (MRSA) are endemic in hospitals throughout Ireland and present a major concern in hospital hygiene causing significant morbidity, mortality and imposing a significant financial burden. This is particularly true in the field of orthopaedic surgery where a nosocomial MRSA infection can prove catastrophic to a patient's recovery from surgery. Much has been made of the possibility of healthcare workers acting as vectors for the transmission of MRSA and other pathogenic bacteria in the hospital setting. This focus has led to the implementation of strict hand decontamination policies in hospitals in order to counter the possibility of staff - patient transmission of such bacteria. Investigations have also attempted to assess the bacterial contamination of work uniforms such as white coats, ties and scrubs. An area that has been generally overlooked however, is the assessment of the bacterial contamination some of the most commonly handled items of many healthcare workers, namely pagers and mobile phones. In this study we aimed to assess the potential for these items to act as reservoirs for MRSA contamination and thus propagate its transmission in the hospital setting. Methods. Our study was performed at Cappagh National Orthopaedic Hospital, Dublin. We swabbed and cultured a sample of the pagers and mobile phones of staff. Questionnaires to assess the demographics of the staff sampled as well as the routine cleaning habits for their phone/pagers were also administered. Results. Bacteria were isolated from all pagers and mobile phones. Included in these isolated bacteria were MRSA and other potentially pathogenic organisms. Regular cleaning/disinfection of mobile phones and pagers was virtually non existent, either on a personal or institutional level. Conclusions. Mobile phones/pagers have thus far been generally overlooked as a possible reservoir and vector for the transmission of potentially pathogenic bacteria such as MRSA. We suggest that education about these possibilities takes place along with regular disinfection of these items in order to reduce the transmission of MRSA and other potentially pathogenic bacteria in the hospital setting

Prior work in the setting of MRSA (clinical isolate), showed that enhancement of Ti6Al4V with anodized nanotubes apparently disrupts the formation and adhesion of MRSA biofilm. The greater amount of cultured MRSA using effluent released from in vitro nanotube surfaces by sonication, compared with thermal plasma sprayed (TPS), indicated probable disruption of biofilm formation and adhesion. The use of nanosilver nanotubes in vivo in a rabbit model showed that after 1 week of infection followed by 1 week of vancomycin treatment, the nanotube MRSA level was 30% that of TPS, and the nanosilver nanotube MRSA level was only 5% of TPS. The implementation of the technology will enhance the remodeled bone locking ability of rough TPS, with surface nanotubes that provide antibacterial properties and increased bone adhesion. Lap shear tests of the nanotubes were performed according to ASTM F1044. In multiple tests, circular adhesive films bonded Ti6Al4V bars containing nanotubes with plain Ti6Al4V. The assemblies were suitably arranged in a tensile tester and pulled to shear failure. There were three modes of failure; shear failure within the adhesive, failure of the adhesive from the plain titanium, and shear failure of the nanotubes from the bar. Tests determined the shear strength of the adhesive and its bonding strength to bare titanium. ImageJ software determined the area of each of the three failure modes. From this analysis, the shear strength of the nanotubes of each sample was calculated. The analyses showed the shear strength of the nanotubes to be as high as 65MPa (9,500psi) with a more typical shear strength of 55MPa (8,000 psi), and several surfaces with 45MPa (6,000 psi). The literature presents models predicting the shear stress in bonded hip stems. Assuming the TPS with nanotubes performs similar to a bonded hip stem, owing to the locking of the bone with the TPS, a typical shear stress prediction for physiological loads is approximately 10 MPa. The nanotube shear strengths were 4–6 times higher than the expected stress during use. For any figures or tables, please contact authors directly

The objective of this study was to determine the effectiveness of screening and successful treatment of methicillin-resistant Staphylococcus aureus (MRSA) colonisation in elective orthopaedic patients on the subsequent risk of developing a surgical site infection (SSI) with MRSA. We screened 5933 elective orthopaedic in-patients for MRSA at pre-operative assessment. Of these, 108 (1.8%) were colonised with MRSA and 90 subsequently underwent surgery. Despite effective eradication therapy, six of these (6.7%) had an SSI within one year of surgery. Among these infections, deep sepsis occurred in four cases (4.4%) and superficial infection in two (2.2%). The responsible organism in four of the six cases was MRSA. Further analysis showed that patients undergoing surgery for joint replacement of the lower limb were at significantly increased risk of an SSI if previously colonised with MRSA. We conclude that previously MRSA-colonised patients undergoing elective surgery are at an increased risk of an SSI compared with other elective patients, and that this risk is significant for those undergoing joint replacement of the lower limb. Furthermore, when an infection occurs, it is likely to be due to MRSA

This study examines the case of a spondylodiscitis in the thoracic spine caused by MRSA which led to two orthopaedic surgeries followed by rehabilitation. A 72.6 year old woman suffered a cutaneous infection with herpes zoster on the right dorsal thorax – 2 weeks later she presented a sepsis by MSSA. 2 month later she lamented sever pain in the thoracic column. She were hospitalized presenting a sepsis by MRSA. One month later it was found an infectious spondylodiscitis from thoracic vertebra T 8 to T 11 with destruction of the intervertebral spaces. To eliminate the infection and stabilize the dorsal column she was undertaken an first orthopaedic surgery by dorsal decompression and dorsal spondylodesis from T 6 – L 2; intraoperative microbiology: MRSA. 3 month later she was undertaken a second surgery by a lateral transthoracic decompression and intervertebral stabilization from T 9 – T 10 with tricortical bone chips and inlay of sponge with Calcibon and Gentamycin. The following rehabilitation took her to a reasonable result. The cost of the first treatment with dorsal stabilization was € 17.694,24, the second surgery was € 13.678,88; the cost of both rehabilitations was € 4.160,00. The finally costs for the whole treatment for the insurance was € 47,442,62. This retrospective case report shows the high costs for a treatment of spondylodiscitis caused by MRSA, not taking in consideration the harm and prolonged pain of the patient

Introduction. MRSA colonisation increases the risk of acquiring a surgical site infection (SSI). Screening identifies such patients and provides them with suitable eradication treatment prior to surgery to decrease their risk of infection. Our aim was to determine whether receiving effective eradication therapy decreases the risk of infection in a patient previously screening positive for MRSA to that of someone screening negative. Methods. 1061 patients underwent elective total knee or hip replacement between March 2008 and July 2010. 1047 had pre-operative screening for MRSA and MSSA using nasal and perineum swabs. If positive for MRSA they underwent a course of eradication treatment and were required to provide a negative swab result prior to undertaking surgery. However during the time of this study those screening positive for MSSA did not receive eradication treatment. Surgical site infections were recorded and the rate of infection, relative risk and odds ration were calculated. Results. Overall 24 (2.26%) SSIs were observed post-operatively. There were 15 infections (1.78%) in 851 patients screening negative. Twenty-five patients (2.4%) screened positive for MRSA with 2 (8%) suffering a post-operative infection (Relative Risk 4.49, Odds Ratio 4.79). 181 patients (17.3%) screened positive for MSSA with 7 (3.9%) suffering an SSI (Relative Risk 2.12, Odds Ratio 2.22). The group screening positive for MRSA was at a statistically significantly higher risk of suffering a post-operative infection (p=0.03). Conclusion. An increased rate of post-operative infection is observed in patients screening positive for MRSA pre-operatively in spite of the administration of eradication therapy and the provision of a negative swab prior to surgery. A second group of patients screening positive for MSSA are also at a higher risk of post-operative infection than those that screen negative. Further work is required to establish if eradication therapy would decrease the SSI rate amongst this group

To describe the prevalence and incidence of Methicillin-resistant Staphylococcus aureus (MRSA) colonisation during the patient journey for patients admitted to orthopaedic and trauma wards, we carried out a prospective audit at the University Hospital of North Staffordshire NHS Trust, England. The Study Population comprised patients admitted to the trauma and elective orthopaedic wards, with an expected stay of 48 hours or more between March and May 2003. Patients were swabbed for MRSA colonisation on ward admission, transfer to another ward and discharge from hospital. Elective patients undergoing major joint surgery were also swabbed at a pre-operative assessment clinic. Colonised patients were treated depending on individual risk assessment. Five hundred and fifty-nine eligible patients were admitted to hospital. Of these, 323 (101 elective, 192 trauma and 30 non-orthopaedic) patients were included in the study, of whom 28 elective patients (28%), 43 trauma patients (22%), and seven non-orthopaedic patients (23%) were colonised with MRSA at any time during the audit period. Of the 80 patients identified as negative for MRSA colonisation at pre-assessment screening and included in the audit, ten (9.5%) were found to be colonised on admission. There is a high prevalence of MRSA colonisation in patients admitted to the orthopaedic and trauma wards in our setting. A policy of pre-admission screening, though able to identify MRSA carriage does not guarantee that patients are not colonised in the period between screening and admission. Consideration should be given to screening all patients for MRSA who are admitted to an orthopaedic ward

Purpose. The consequences of infection in orthopedic oncology patients are well known. Methicillin sensitive- and resistant Staphylococcus aureus (MSSA and MRSA, respectively) are common infecting organisms which may colonize patients pre-operatively. The prevalence of colonization in orthopedic oncology patients is unknown. We sought to prospectively establish the prevalence of MSSA and MRSA colonization in an orthopedic oncology patient population. Method. Beginning in September 2009, all oncology patients of a single surgical service were prospectively screened pre-operatively for MSSA and MRSA colonization using PCR nasal swabs as part of an infection control protocol. Patients identified as carriers underwent decolonization treatment peri-operatively. Results. One hundred thirty-nine oncology patients underwent 143 independent procedures with orthopedics as the primary service from September 1, 2009 August 31, 2010. MSSA/MRSA screening capture rate was 93%. Prevalence of MSSA colonization was 22% and MRSA colonization was 3.8%. MSSA colonization was not associated with malignant diagnosis (p=1.0), or recent chemo- or radiotherapy treatment (p>0.50 for both). All MRSA colonized patients had undergone inpatient oncology treatment or had occupational exposure to MRSA in the last year. Post-operative infection developed in 4/124 patients with type I surgical incisions (3.2%). Infecting organisms were coagulase negative Staphylococcus (n=2), MSSA (n=1), and Streptococcus (n=1). Conclusion. MSSA colonization rates in orthopedic oncology patients are similar to reported population values. MRSA colonization rates are low. Patient diagnosis or adjuvant treatments do not appear to influence colonization rates. MRSA colonization was only seen in patients with inpatient or occupational exposure to MRSA

Aim. This study quantified changes in the microbiology of osteomyelitis in a single specialist centre within the UK. The rate of infection with multi-drug-resistant (MDR) bacteria was measured over a ten year period in 388 patients. Method. Patients with confirmed osteomyelitis who received curative surgery from 2013–2017 were included (n=222). Microbiology was compared to patients from a cohort between 2001–2004, using the same diagnostic criteria (n=166). 1. The proportion of MDR bacterial pathogens. 2. from deep tissue culture in these cohorts were compared. Pathogens were analysed according to aetiology and the presence of metal-work. Results. Both cohorts had similar baseline characteristics. A median of five tissue samples were submitted for each patient. The proportions of specific pathogens remained unchanged between the two cohorts, with the exception of a decrease in the proportion of coagulase-negative Staphylococcus (CoNS) (12.7% vs 5.3%, p<0.05). Although the overall proportion of Staphylococcus aureus remained similar, the rate of MRSA infection decreased in the 2013–2017 cohort when compared to the 2001–2004 cohort (30.7% vs. 10.5% of Staphylococcus aureus, p<0.05). However, the proportion of MDR Enterococcus, Pseudomonas and Enterobacteriaceae did not differ between the two cohorts (37.3% vs. 35.7%). There were no differences in microbiology of the 2013–2017 cohort that related to presence of metal-work or aetiology of infection. A higher proportion of haematogenous osteomyelitis were culture-negative compared to other aetiologies (37.1% versus 20.3%). Conclusions. In this UK centre over the past 10 years, rates of MRSA osteomyelitis have fallen by two thirds, which is in line with the reducing rate of MRSA bacteraemia nationally. However, the proportion of other MDR bacteria remained unchanged. A decrease in the proportion of CoNS may reflect improved sampling technique and culture. Furthermore, this study demonstrated that classification by aetiology or the presence of metal-work does not predict the pathogen in adults with chronic osteomyelitis

Purpose. Surgical site infection (SSI) is an infrequent but serious complication of total joint arthroplasty (TJA). Orthopaedic SSI causes substantial morbidity, prolonging the hospital stay by a median of 2 weeks, doubling the rates of rehospitalization, and more than tripling overall healthcare costs. Colonization with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) is known to be associated with an increased risk of subsequent SSI. Carriers are two to nine times more likely to acquire S. aureus SSIs than non-carriers. Screening of the nose and throat for MRSA colonization and preoperative patient decolonization have been shown to decrease the incidence of subsequent MRSA infection. The aim of this study was to investigate the association between the results of MRSA colonization screening and the incidence of SSI in our hospital. Materials and Methods. Between June 2007 and June 2010, 238 patients were admitted for TJA, among whom 235 underwent preoperative assessment that included screening of the nose and throat for MRSA colonization. Fifty-nine of these patients underwent total hip arthroplasty (THA), 69 underwent total knee arthroplasty (TKA), 6 underwent unilateral knee arthroplasty (UKA), and 101 underwent bipolar hip prosthesis arthroplasty (BPH). The mean age of the patients was 72.7 (49–95) years and the male to female ratio was 1:3.8. We analyzed these patients retrospectively, and determined the site of colonization, eradication prior to surgery, and subsequent development of SSI in the year after surgery. SSI was defined according to the criteria established by the Centers for Disease Control and Prevention. Results. MRSA colonization was positive in 12 patients (5.1%) at the initial preoperative assessment (Fig. 1). All except 2 of the positive patients underwent nasal eradication with mupirocin 2% three times daily for three days. Eight of 10 patients were confirmed to be MRSA-negative after re-swabbing. During surgery, all patients received perioperative antibiotic prophylaxis. The standard regimen was cefazolin 1 g administered 15 to 30 min before incision, followed by 1 g every 3 hours until skin closure. One hundred eighty-six patients were monitored for development of SSIs for 1 year after TJA. Among these patients, 1 in the MRSA-positive group and 1 in the negative group developed MRSA SSIs (P<0.01)(Fig. 2). Discussion. Bode et al. recently reported that rapid screening and decolonizing of nasal S. aureus carriers with intranasal mupirocin prevented SSIs after mixed surgery. However, several studies of the effect of screening and decolonization for such carriers have yielded paradoxical findings because of differences in study design or sample size. Conclusion. We conclude that MRSA-colonized patients undergoing TJA are at an increased risk of SSI, despite eradication therapy prior to surgery. Use of prophylactic antibiotics such as vancomycin or teicoplanin may be beneficial

Background. Hospital acquired MRSA is globally endemic and is a leading cause of surgical site infection (SSI). Of great concern is the emergence of community acquired MRSA (CA MRSA) with its unique virulence characteristics. Infected hip or knee prostheses due to MRSA are associated with multiple reoperations and prolonged hospital stay. Few studies have been done to assess for risk of SSI in MRSA carriers undergoing elective orthopaedic surgery following decolonisation. However in these studies, the eradication status was not confirmed prior to proceeding for surgical intervention. Aim. The purpose of the study was to evaluate the incidence of SSI in MRSA carriers undergoing elective hip and knee arthroplasty, who had confirmed eradication of MRSA carrier status and to compare it with incidence of SSI in non MRSA carriers. Material and Methods. This is a retrospective analysis of 6613 patients who underwent elective hip (3347) and knee arthroplasty (3266) at our institution between January 2008 and August 2012. A cohort of patients who were preoperatively colonised with MRSA was identified. These patients were offered decolonisation protocol and successful eradication was ensured prior to surgery. The MRSA negative patients served as the control group and we looked into the incidence of SSI in both groups up to one year after surgery. Categorical variables were investigated between groups using chi-squared tests and p value of < 0.05 was taken as significant. Results. Out of 6613 patients, MRSA colonisation was observed in 83 patients (a mean age of 76 years with a M:F ratio of 1:1.2) pre-operatively with a colonisation rate of 1.3%. A total of 79 patients had confirmed eradication of carrier status prior to surgical intervention. Of these 38 were THRs and 41 were TKRs. Total number of MRSA negative patients were 6530 with 3307 THRs and 3223 TKRs in control group. Teicoplanin was used for antibiotic prophylaxis in these patients. 5 of 79 patients had “deep SSI” within 1 year of surgery giving an infection rate of 6.32%. There were 2 MRSA infections in hip replacements with an infection rate of 5.26%. There were 2 MRSA and 1 MSSA infection in TKR resulting in an infection rate of 7.31%. These patients did not belong to the “high-risk” group for MRSA colonisation. A significant statistical difference in infection rates from MRSA negative control group was noted, which had a deep sepsis rate of 1.17% (p value − 0.03) in THRs and 0.87% in TKRs (p value − 0.0016). Conclusions and Clinical Implication. In spite of a selective treatment program for carriers and confirmed eradication in terms of achieving a reduction in the rate of SSI, there is still a significantly increased risk of SSI in MRSA colonised patients undergoing hip and knee replacements. Also, should infection develop, MRSA is the most likely causative organism. Patients should be made aware of this higher risk of infection and the serious consequences of developing MRSA SSI

Noting a decreasing number of transfemoral amputations following infection of Total Knee Arthroplasty (TKA) I studied a case of a patient which suffered an amputation following infection of TKA by MRSA. With assistance of all hospitals and the NHS it was able to classify all costs of this poor case. This study exposes a drama of a person which received a Total Knee Arthroplasty in the right knee at 66.0 years. 2 weeks after the implantation of TKA she presented a wound secretion, the microbiology shows: MRSA, Pseudomonas aeroguinos and Streptococcus. 4 surgical revisions followed without removing the TKA. 35 month later, with 68.9 years it was indispensable to remove the TKA in a 6th operation, implanting a spacer with Vancomycine. 1 month later removing of the spacer and implanting a second cemented TKA in the 7th surgery. With 70.2 years the removal of the second TKA was necessary because of infection with Pseudomonas aeroguinosa and Morganelli morganii. Now implantation of another spacer with Vancomycine. 1 month later with 70.3 years removal of the spacer molding an arthrodesis of the knee using an intramedullary femur to tibia rod. After that 4 revision surgeries with changing the intramedullary rod some wound revisions followed, ending in the 23rd operation with a transfemoral amputation with 71.1 years – 5 years after primary TKA. 3 month after transfemoral amputation the patient presented high temperature and a secretion of the scarf of the TT-stump; microbiology: MRSA. 2 more surgeries are necessary to stop the infection. This patient suffered over all 25 surgical procedures in 5.5 years. The hospitalization for acute infection of TKA led to 431 days in different hospitals in 33 months. Statement of charges from the hospitals € 74.046,92 in the last three years before amputation. Payments by the health insurance € 155.424,00 for all procedures. We will demonstrate the different costs of hospital procedures and distribution for the insurance for all performances

To review the effect of MRSA screening, ward ring-fencing and other significant factors on elective orthopaedic operation cancellations: and to study the effect of introducing a multi-disciplinary trauma management system on trauma operation cancellations, we carried out a study at the Royal Gwent Hospital, a district general hospital accepting general emergency admissions. It took the form of a prospective audit of all elective orthopaedic and trauma cancellations from 1 October to 10 November 2002, and in the same period of 2004. Definitions: an ‘elective cancellation’: deemed medically fit at SHO pre-admission assessment; MRSA swabbed with negative results then subsequently cancelled from an elective theatre list under the headings, ‘ward breech by other unscreened patients’, ‘unfit for surgery’ (anaesthetic decision), ‘lack of beds’ and ‘other’ (lack of surgical assistant, theatre time, theatre staff and operation not required). A ‘trauma cancellation’: acute admission with allocation of theatre space; subsequently cancelled under the headings, ‘unfit for surgery’ (anaesthetic decision), ‘lack of theatre time’, ‘surgery not required’ and ‘other’ (patient refused surgery, absconded, incorrect listing, no surgical assistant or theatre staff). Results. In the six week period 198 and 226 elective patients were listed in 2002 and 2004 respectively. 52% were cancelled in 2002 and 35% in 2004, most frequently by ‘ward breech by other unscreened patient’. 234 and 269 trauma cases were listed in 2002 and 2004 respectively. 26% were cancelled in 2002 and 16% in 2004, most frequently in 2002 by ‘unfit for surgery’, and ‘surgery not required’; and in 2004 ‘lack of theatre time’. The MRSA ring-fencing policy was breached frequently by unscreened emergency patients. An elective unit separate from the main hospital may prevent these cancellations. The multi-disciplinary trauma management scheme reduced trauma cancellations, but other factors have reduced theatre efficiency

Periprosthetic joint infection (PJI) remains one of the most devastating complications that can occur following total joint arthroplasty. Failure rate of standard treatment for PJI is estimated to be around 40% at two years post revision surgery. A major clinical challenge contributing to treatment failure and antibiotics tolerance is the biofilm formation on implant surfaces. Lytic bacteriophages (phages) can target biofilm associated bacteria at localized sites of infection by penetrating and disrupting biofilm matrices; furthermore, phage replication within the biofilm leads to high local concentrations resulting in a powerful therapeutic effect. The aim of this study is to test if phage cocktail has better antimicrobial effect than vancomycin or a single agent phage against biofilm forming MRSA clinical strain Staphylococcus aureus (S. aureus). S. aureus BP043 was utilized in this study. This strain is a PJI clinical isolate, methicillin resistant (MRSA) and biofilm-former. Three lytic phages, namely, 44AHJD, Team1 and P68, known to infect S. aureus, were tested for their efficiency against S. aureus BP043. The ability of the phages to eliminate S. aureus BP043 planktonic or biofilm cultures was tested either as singular phages or as a cocktail of the three phages. Planktonic cells were adjusted to ∼ 1×109 CFU/mL in tryptic soy broth (TSB) and each phage was added alone or as a cocktail at ∼ 1×109 PFU/mL with moi of 1 (a multiplicity of infection). Bacterial growth was assessed by measuring optical densities at 24hr and was compared to the control of S. aureus BP043 with no phage. BP043 biofilms was grown for 24hr on plasma sprayed titanium (Ti-6Al-4V) alloy disc surfaces. Mature biofilms were then treated with one of the three phages or a cocktail of the 3 phages for 24hr at ∼ 1×109 PFU/mL in TSB. Then, biofilms were dislodged, and bacterial survival was assessed by plating on tryptic soy agar plates. Survival in treated biofilms was compared to control biofilm that was exposed only to TSB. Planktonic cells growth in the presence of phage 44AHJD was reduced significantly (p <0.0001) after 24hr compared to the control. The other two phages did not show a similar pattern when used alone. The reduction in growth was more pronounced when the three phages were combined together (p <0.0001, compared to the control, p=0.011 3, 44AHJD alone versus 3 phages). Exposing BP043 biofilm to the phage cocktail resulted in more than three logs (CFU/mL) reduction in bacterial load residing in the biofilm while no effect was detected when either vancomycin or each phage was used solely. We have demonstrated that the usage of lytic phage cocktail contributes to better clearance of planktonic cultures of the S. aureus MRSA isolate. More importantly, viable bacteria in the biofilms that were grown on plasma sprayed titanium discs were reduced by more than 37% when a phage cocktail was used compared to using a single phage or vancomycin. This work is aimed at gathering preclinical evidence for using phage as a new therapeutic avenue to treat PJI

From 1998 to July 2003 admissions for elective arthroplasty surgery in Derriford Hospital were nursed alongside other orthopaedic and general medical patients. Since August 2003 a policy of pre-operative MRSA screening and a unit reserved exclusively for MRSA-free joint replacement patients have been used. No transfers from other wards were allowed. Patients positive on screening underwent eradication and were admitted to a different ward where they received teicoplanin on induction (in addition to standard policy cephradine). All post-operative wound infections following THR & TKR were monitored (NINSS surveillance system). Infections within 3 months were recorded. A control of non-screened hip hemi-arthroplasty patients was used to ensure a departmental wide reduction in MRSA was not occurring. 1.9% MRSA carriage rate was detected over the study. Before screening, 0.59% of 3386 cases were acutely infected with MRSA. After institution of screening and a dedicated MRSA free unit, 0.10% of 1034 were acutely infected. This was a 6-fold decrease (p<0.05). The infection noted was in a patient treated outside the ringfenced unit on High Dependency. In fact the infection rate on the ringfenced unit was zero. MRSA infection in the control was statistically unchanged during this period. Conclusion. A policy of MRSA screening and an MRSA free joint replacement ward reduces the incidence of acute MRSA infections

Methicillin– resistant Staphylococcus aureus (MRSA) infected gap non –union of long bones fractures is a challenge to manage. Treatment options are limited such a Ilizarov bone transport, vascularized bone free transfer etc. These techniques have complications and require expertise. We present a rare case with MRSA infected nonunion and bone defect 5cm of ulna which was managed with the induced membrane formation. A 33-years old male presented to outpatient department, 2 months after internal fixation on both left bone forearm fractures (Gustillo I). There was pus discharge from the operative site of ulna. Culture results: MRSA, C-Reactive Protein (CRP): 2,58 (0–5), Erythrocyte Sedimentation Rate (ESR): 42 (0–20). Intravenous (iv) Teicoplanin and Rifampicin were administrated and after one month no topic symptoms and CRP- ESR were normal. One month later he had again actively draining sinus (CRP: 1,47 ESR:22). The implant (ulna) was removed and a gap 5 cm was created at the fracture site (necrotic-infected bone debrided), which was filled by cemented spacer (Tobramycin and vancomycin). An external fixator was applied to ulna. Radius was not involved. Post op. iv the same antibiotics for 4 weeks. At the end of 8 weeks, the spacer was removed and the gap was filled with autologous cancellous bone graft (iliac crest). After 5 months the patient was reviewed. No any clinical and functional problems. Radiographics and CT-images were showed osseous consolidation. This technique (called as ‘Masquelet’) gives promising result in the management of infected long bone defects in upper extremity

Aim

The management of PJIs is slowed down by the presence of bacteria forming biofilms where they may withstand antibiotic therapy. The use of adjuvant strategies, such as hydrolytic enzymes cocktail targeting biofilm matrices and facilitating their dispersion, is a promising option to limit impact of biofilms. Our aim was to evaluate the effect of enzymes cocktail combined with antibiotic dual therapy of rifampicin and vancomycin in a relevant in-vitro model.

Staphylococcus aureus is one of the leading causes of surgical site infection (SSI). Over the past decade there has been an increase in methicillin-resistant S. aureus (MRSA). This is a subpopulation of the bacterium with unique resistance and virulence characteristics. Nasal colonisation with either S. aureus or MRSA has been demonstrated to be an important independent risk factor associated with the increasing incidence and severity of SSI after orthopaedic surgery. Furthermore, there is an economic burden related to SSI following orthopaedic surgery, with MRSA-associated SSI leading to longer hospital stays and increased hospital costs. Although there is some controversy about the effectiveness of screening and eradication programmes, the literature suggests that patients should be screened and MRSA-positive patients treated before surgical admission in order to reduce the risk of SSI. Cite this article: Bone Joint J 2013;95-B:4–9

Bactericidal levels of antibiotics are difficult to achieve in infected total joint arthroplasty when intravenous antibiotics or antibiotic-loaded cement spacers are used, but intra-articular (IA) delivery of antibiotics has been effective in several studies. This paper describes a protocol for IA delivery of antibiotics in infected knee arthroplasty, and summarises the results of a pharmacokinetic study and two clinical follow-up studies of especially difficult groups: methicillin-resistant Staphylococcus aureus and failed two-stage revision. In the pharmacokinetic study, the mean synovial vancomycin peak level was 9242 (3956 to 32 150; sd 7608 μg/mL) among the 11 patients studied. Serum trough level ranged from 4.2 to 25.2 μg/mL (mean, 12.3 μg/mL; average of 9.6% of the joint trough value), which exceeded minimal inhibitory concentration. The success rate exceeded 95% in the two clinical groups. IA delivery of antibiotics is shown to be safe and effective, and is now the first option for treatment of infected total joint arthroplasty in our institution.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):31–6.

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 implant infections

Aim. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with serious cases of community-onset skin and musculoskeletal infections (Co-SMSI). Molecular epidemiology analysis of CA-MRSA recovered from skin and soft tissues specimens is lacking in Latin America. This study aimed to identify phenotypic and genotypic features of MRSA isolates recovered from patients presenting Co-SMSI. Methods. Consecutive MRSA isolates recovered from Co-SMSI of patients admitted from March 2022 to January 2023 in a Brazilian teaching hospital were tested for antimicrobial resistance and characterized by their genotypic features. Identification was carried out by automated method and through MALDI-TOF MS. Antimicrobial susceptibility was tested by disk diffusion, broth microdilution and E-test strips for determination of the minimal inhibitory concentration (MIC) according to recommendations from the Brazilian Committee on Antimicrobial Susceptibility Testing (BrCAST) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). Gene mecA characterization and Sccmec typing were performed by multiplex polymerase chain reaction (PCR) assay, and gene lukF detection by single PCR. Patients were prospectively followed up for two months, in order to determine their clinical characteristics and outcomes. Results. Overall, 48 Staphylococcus aureus isolates were obtained from 68 samples recovered from patients with Co-SMSI. Twenty two (42%) were phenotypically characterized as MRSA, although mecA gene was only identified in 20 of those samples. Sccmec was untypable in 12 isolates, Sccmec was type II in 4 isolates and 2 were classified as type IVa. LukF gene was identified in 5 isolates. Antimicrobial resistance profile showed that all isolates were susceptible to linezolid and vancomycin with MIC = 1 and MIC = 2 in 66,7% and 33.3%, respectively. Susceptibility to quinolones was worryingly low and none of the isolates were sensitive to usual doses of ciprofloxacin and levofloxacin, and showed increased rates of resistance to increased exposure to these drugs, as well. Isolates were both susceptible to gentamicin and tetracycline in 85% and resistance to also Sulfamethoxazole/Trimethoprim occurred in only 2 isolates. Mortality rate evaluated within 1 month of the initial evaluation was 10% among MRSA isolates. Conclusions. Our results showed that CA-MRSA isolates causing Co-SMSI demonstrated an alarming pattern of multidrug resistance, including to β-lactam and quinolones, which have been commonly prescribed as empirical therapy for patients with skin, soft tissue and musculoskeletal infections