Aims. Periprosthetic joint infections (PJIs) are rare, but represent a great burden for the patient. In addition, the incidence of methicillin-resistant Staphylococcus aureus (MRSA) is increasing. The aim of this rat experiment was therefore to compare the antibiotics commonly used in the treatment of PJIs caused by MRSA. Methods. For this purpose, sterilized steel implants were implanted into the femur of 77 rats. The metal devices were inoculated with suspensions of two different MRSA strains. The animals were divided into groups and treated with vancomycin, linezolid, cotrimoxazole, or rifampin as monotherapy, or with combination of antibiotics over a period of 14 days. After a two-day antibiotic-free interval, the implant was explanted, and bone, muscle, and periarticular tissue were microbiologically analyzed. Results. Vancomycin and linezolid were able to significantly (p < 0.05) reduce the MRSA bacterial count at implants. No significant effect was found at the bone. Rifampin was the only monotherapy that significantly reduced the bacterial count on implant and bone. The combination with vancomycin or linezolid showed significant efficacy. Treatment with cotrimoxazole alone did not achieve a significant bacterial count reduction. The combination of linezolid plus rifampin was significantly more effective on implant and bone than the control group in both trials. Conclusion. Although rifampicin is effective as a monotherapy, it should not be used because of the high rate of resistance development. Our animal experiments showed the great importance of combination antibiotic therapies. In the future, investigations with higher case numbers, varied bacterial concentrations, and changes in individual drug dosages will be necessary to be able to draw an exact comparison, possibly within a clinical trial. Cite this article: Bone Joint Res 2022;11(3):143–151

We examined rates of MRSA wound infection in patients admitted to the Leicester Royal Infirmary Trauma Unit between January 2004 and June 2006. The influence of MRSA status at the time of their admission, together with age, sex and diagnosis were examined using multivariant analysis. 3.2%(79/2473)) were MRSA carriers at time of admission and 96.8%(2394/2473) were MRSA negative. Those carrying MRSA at the time of admission were more likely to develop MRSA surgical site infections [8.8% (7/79)] as compared to non MRSA carrier at the time of admission [2.2% (54/2394), p< 0.001]. Further analysis revealed that hip fracture and increasing age (linear increase in relative risk of 1.8% per year) were also risk factors. MRSA carriage at admission, age and pathology are all associated with an increased rate of developing MRSA wound infections. Identification of such risk factors at admission helps to target health care resources such as the use of glycopeptides at induction and increased vigilance for wound infection in the post operative phase

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

Since Aug‘03 pre-operative MRSA screening & a ward reserved exclusively for MRSA free joint replacement patients has been used. All postoperative wound infections within 3 months following THR & TKR were monitored. Before screening, 0.59% of 3386 were acutely infected with MRSA. After institution of study policy, 0.10% of 1034, were infected with MRSA.. This was a 6 fold decrease (p< 0.05). The rate of MRSA infection in a control of hemiarthroplasties was unchanged during this period. A policy of MRSA screening & an MRSA free joint replacement ward reduces the incidence of acute MRSA infections

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

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

Objective: To identify institution specific risk factors for developing MRSA surgical site infection (SSI) and develop an objective mechanism to estimate the probability of MRSA infection in a given patient admitted to the orthopaedic unit. Design: A cohort study was performed to identify risk factors in all patients who had MRSA infection during admission on the orthopaedic unit between January 2002 and December 2004. Logistic regression was used to model the likelihood of MRSA. A stepwise approach was employed to derive a model. The MRSA prediction tool was developed from the final model. Results: Of the 11 characteristics included in the logistic regression, the features that strongly predicted a MRSA infection were ASA grade, patient’s residence and reason for admission. 110 had MRSA infection in their surgical wound. 83 of 110 (75.5%) patients were non-elective admissions, of which 49 (60%) were proximal femur fractures. 20% of proximal femur fractures admitted from nursing home and 7.8% from their own homes developed SSI with MRSA. This cohort of SSI with MRSA had an average of 5.7(1–18) previous admissions. 25 (23%) had been previously colonised with MRSA. Majority of them (76%) were between 70–90 years old and were ASA grade 3–4. Conclusion: Through multivariate modelling technique we were able to identify the most important determinants of patients developing SSI with MRSA in our institute and develop a tool to predict the probability of MRSA in a given patient. This knowledge can be used to guide the use of appropriate prophylactic antibiotic and to take other required measures to avoid the SSI with MRSA

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: In recent years an increased trend in MRSA infection has been seen in hospitals and the community, with colonisation rates of between 4 – 17% reported in these patient groups. There is also an association between carriage of Staph. Aureus and staphylococcal surgical wound infection. In our institution there has been concern regarding MRSA surgical site infection and possible cross contamination of elective and emergency patients. There would be implications for implant related infections if this were to occur. This had prompted the unit to consider adopting a screening programme to identify and treat MRSA carriers. This would aim to minimise risk of post operative infection and cross infection. As little was actually known about the MRSA colonisation rates of admissions to our hospital we undertook the following project to assess the feasibility and effectiveness of implementing such a screening programme. Aim: To ascertain the incidence of colonisation with MRSA, rate of wound infection and the associated risk factors in patients admitted to the trauma ward with a fractured neck of femur. Method: A prospective, blinded case series of 100 consecutive patients admitted to the trauma ward with a fractured neck of femur. Three swabs (axilla, nasal and perineum) were taken within 24 hours of admission. Data from each patient was collected to ascertain the presence of risk factors linked to MRSA colonisation and each patient was followed until discharged to assess for surgical site infection. Results: 304 swabs were taken from 100 patients. Age range 60–97. 26% admitted from institutionalised care and 74% admitted from their own home. Four patients were colonised with MRSA on admission (2 nasal, 2 perineal). An association was seen between patients colonised on admission and long term or recent residence in institutionalised care. One of these patients went on to develop colonisation of the surgical wound however this did not lead to surgical site infection and the patient was successfully treated with MRSA eradication therapy only. In these 4 patients all wounds healed satisfactorily with no evidence of infection. There were three superficial surgical site infections postoperatively, all in individuals who were clear on their admission screening. Of these two were due to MRSA and one was due to MSSA. There were no cases of deep infection requiring further surgery. Conclusion:While MRSA continues to be a growing concern we found that, in our hospital, rates of MRSA colonisation and subsequent infection were not high. There were no documented cases of MRSA wound infection in colonised individuals. Given the cost involved in swabbing all patients to detect these low levels of colonisation we do not feel that an expensive screening regimen would be cost effective or justified in our institution

Nosocomial infection with methicillin-resistant Staphylococcus aureus (MRSA) is on the increase and is expensive to treat. MRSA surgical wound infection may have disastrous consequences, particularly in an orthopaedic setting. We studied the rate of MRSA colonization in an important subgroup of orthopaedic patients. 50 nursing home residents were retrospectively reviewed with regard to their MRSA status on admission to an orthopaedic ward with fractured neck of femur. As is policy in our institution, all patients from nursing homes or other institutions are screened for MRSA on admission. Of the 50 nursing home patients requiring a hemi-arthroplasty, 16%(8) were MRSA positive. 2%(1/50) acquired MRSA infection while I hospital, while the remaining 14%(7/50) were carriers on admission. 4%(2/50) developed sepsis postoperatively, followed by multiorgan failure and death. 4% had their MRSA cleared prior to discharge, while 8% remained positive on discharge. All patients undergoing hemiarthroplasty received cefuroxime, unless allergic, as prophylaxis at induction. These findings of considerable MRSA carriage in nursing home patients is particularly relevant today, as the number of patients in nursing homes continues to grow as the population ages. The patient population in nursing homes is susceptible to infection because of the physiological changes that occur with ageing, the underlying chronic diseases of the patients and the institutional environment within which residents socialize and live. Nursing home residents presenting to orthopaedic units for surgery are a unique group in repairing careful consideration

Introduction. In 2011 the Scottish Government published national MRSA screening requirements. A comparison of Orthopaedic and ENT elective surgery intended to juxtapose a specialty known to take MRSA screening seriously with one that has little clinical concern with regards MRSA infection. ENT surgery parallels Orthopaedics in using implants and there potentially being MRSA colonisation at or close to the site of surgery. In Orthopaedics MRSA infection is infrequent, but implant infection with antibiotic resistant bacteria has a particularly poor prognosis. In ENT MRSA infection is rare and colonisation does not influence patient care. Aims. An evaluation of MRSA screening practice for elective Orthopaedics and ENT surgery at Gartnavel General Hospital with regards strategy and implementation. Method. Review of 342 consecutive elective ENT patients and 325 Orthopaedic patients attending for inpatient or day case surgery. The reference standards were the regional and national guidelines on MRSA screening. Results. Overall screening rates were 145 (42%) of 342 ENT patients and 270 (83%) of 326 Orthopaedic patients. 100% of Orthopaedic patients admitted (154) were screened, in compliance with both regional and national policy. 91 (70%) of 130 ENT patients admitted were screened for MRSA, and no risk assessment was carried out, which was not in compliance with either regional or national policy. Discussion. Orthopaedic surgery has an established and reliable practice of screening elective inpatient cases, and when identified MRSA colonisation results in a change in patient management. ENT surgery should have established a similar practice according to existing local guidelines. The Government consider ENT a lower risk speciality for MRSA, but still require as a minimum a documented MRSA risk assessment process

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

Patients admitted to trauma wards are routinely screened for MRSA pre-operatively. The majority of them have implant surgery before the screening results were available. The aim of our study was to identify the incidence of MRSA wound infection in these patients and their outcome following it. We randomly reviewed 40 patients who were colonised with MRSA pre-operatively and have had implant surgeries. The case notes, drug charts and the microbiology were reviewed to identify the incidence of MRSA wound infection and its outcome in these patients. The place of residence, site of colonisation and the treatment given were also considered. 70% of the patients were admitted from home and 20% had previous admission within one year. The commonest site colonised is the nose (50%) followed by the perineum in 20%. Multiple sites were colonised in 10% of the patients. Only 50% of them with positive nasal MRSA were given nasal bactroban and chlohexidine wash was given in only 70% of them with MRSA colonisation in other areas. 22.5% (9/40) of the patients developed MRSA infection post operatively and they were treated with vancomycin or teicoplanin. Wound debridement and washout were done in 67.5%. 75% of the MRSA infected wound healed well with no MRSA in the wound site after treatment. 25% of the MRSA infected wounds had persistent MRSA in the wound. As per our study the incidence of MRSA wound infection in patients colonised pre-operatively is about 22.5%. Most cases seem to heal well without much complication with appropriate antibiotics and wound care

MRSA infections are a current concern in the elderly orthopaedic patient, with colonisation rates of between 417% reported in these patient groups. In our institution there has been concern regarding MRSA surgical site infection and cross contamination of elective and emergency patients. This prompted the unit to consider a screening programme to identify MRSA carriers. We undertook the following project to assess the feasibility and effectiveness of implementing such a screening programme. The aim was to to ascertain the incidence of colonisation with MRSA, rate of wound infection and associated risk factors in patients admitted with a fractured proximal femur. This was a prospective, blinded case series of 100 consecutive patients admitted to the trauma ward with a fractured proximal femur. Three swabs (axilla, nasal and perineum) were taken within 24 hours of admission. Data from each patient was collated and each patient was followed until discharge to assess for surgical site infection. The age range was 60–97 years. 26% were admitted from institutional care. Four patients were colonised with MRSA on admission. An association was seen between patients colonised on admission and long term or recent residence in institutional care. One of these patients went on to develop colonisation of the surgical wound however this did not lead to surgical site infection and the patient was successfully treated with MRSA eradication therapy only. In these 4 patients all wounds healed satisfactorily with no evidence of infection. While MRSA continues to be a growing concern in the press we found that rates of colonisation and subsequent infection were not high. There were no documented cases of MRSA wound infection in colonised individuals. Given the cost to detect these low levels of colonisation we do not feel that a screening regime would be cost effective or justified. Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon

Aims. To characterize the intracellular penetration of osteoblasts and osteoclasts by methicillin-resistant Staphylococcus aureus (MRSA) and the antibiotic and detergent susceptibility of MRSA in bone. Methods. Time-lapse confocal microscopy was used to analyze the interaction of MRSA strain USA300 with primary murine osteoblasts and osteoclasts. The effects of early and delayed antibiotic treatments on intracellular and extracellular bacterial colony formation and cell death were quantified. We tested the effects of cefazolin, gentamicin, vancomycin, tetracycline, rifampicin, and ampicillin, as well as agents used in surgical preparation and irrigation. Results. MRSA infiltrated bone-resident cells within 15 to 30 minutes. Penetration was most effectively prevented with early (i.e. 30 minutes) antibiotic administration. The combined administration of rifampicin with other antibiotics potentiated their protective effects against MRSA-induced cytotoxicity and most significantly reduced extracellular bacterial bioburden. Gentamicin-containing compounds were most effective in reducing intracellular MRSA bioburden. Of the surgical preparation agents evaluated, betadine reduced in vitro MRSA growth to the greatest extent. Conclusion. The standard of care for open fractures involves debridement and antibiotics within the first six hours of injury but does not account for the window in which bacteria penetrate cells. Antibiotics must be administered as early as possible after injury or prior to incision to prevent intracellular infestation. Rifampicin can potentiate the capacity of antibiotic regimens to reduce MRSA-induced cytotoxicity. Cite this article:Bone Joint Res. 2020;9(2):49–59

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