Aims. Antibiotic prophylaxis involving timely administration of appropriately dosed antibiotic is considered effective to reduce the risk of surgical site infection (SSI) after total hip and total knee arthroplasty (THA/TKA). Cephalosporins provide effective prophylaxis, although evidence regarding the optimal timing and dosage of prophylactic antibiotics is inconclusive. The aim of this study is to examine the association between cephalosporin prophylaxis dose, timing, and duration, and the risk of SSI after THA/TKA. Methods. A prospective multicentre cohort study was undertaken in consenting adults with osteoarthritis undergoing elective primary TKA/THA at one of 19 high-volume Australian public/private hospitals. Data were collected prior to and for one-year post surgery. Logistic regression was undertaken to explore associations between dose, timing, and duration of cephalosporin prophylaxis and SSI. Data were analyzed for 1,838 participants. There were 264 SSI comprising 63 deep SSI (defined as requiring intravenous antibiotics, readmission, or reoperation) and 161 superficial SSI (defined as requiring oral antibiotics) experienced by 249 (13.6%) participants within 365 days of surgery. Results. In adjusted modelling, factors associated with a significant reduction in any SSI and deep SSI included: correct weight-adjusted dose (any SSI; adjusted odds ratio (aOR) 0.68 (95% confidence interval (CI) 0.47 to 0.99); p = 0.045); commencing preoperative cephalosporin within 60 minutes (any SSI, aOR 0.56 (95% CI 0.36 to 0.89); p = 0.012; deep SSI, aOR 0.29 (95% CI 0.15 to 0.59); p < 0.001) or 60 minutes or longer prior to skin incision (aOR 0.35 (95% CI 0.17 to 0.70); p = 0.004; deep SSI, AOR 0.27 (95% CI 0.09 to 0.83); p = 0.022), compared to at or after skin incision. Other factors significantly associated with an increased risk of any SSI, but not deep SSI alone, were receiving a non-cephalosporin antibiotic preoperatively (aOR 1.35 (95% CI 1.01 to 1.81); p = 0.044) and changing cephalosporin dose (aOR 1.76 (95% CI 1.22 to 2.57); p = 0.002). There was no difference in risk of any or deep SSI between the duration of prophylaxis less than or in excess of 24 hours. Conclusion. Ensuring adequate, weight-adjusted dosing and early, preoperative delivery of prophylactic antibiotics may reduce the risk of SSI in THA/TKA, whereas the duration of prophylaxis beyond 24 hours is unnecessary. Cite this article: Bone Jt Open 2022;3(3):252–260

Aims

Despite recent literature questioning their use, vancomycin and clindamycin often substitute cefazolin as the preoperative antibiotic prophylaxis in primary total knee arthroplasty (TKA), especially in the setting of documented allergy to penicillin. Topical povidone-iodine lavage and vancomycin powder (VIP) are adjuncts that may further broaden antimicrobial coverage, and have shown some promise in recent investigations. The purpose of this study, therefore, is to compare the risk of acute periprosthetic joint infection (PJI) in primary TKA patients who received cefazolin and VIP to those who received a non-cephalosporin alternative and VIP.

Aim. Infection rates after management of open fractures are still high. Existing guidelines regarding prevention of this complication are inhomogeneous. A survey directed to orthopaedic trauma surgeons worldwide aims to give an overview of current practices in the management of open fractures. Method. An international group of trauma surgeons and infection specialists with experience in the field of musculoskeletal infections developed a questionnaire that was distributed via email to all AOTrauma members worldwide. Descriptive statistical analysis was performed. Results. 1197 orthopaedic trauma surgeons answered the survey (response rate: 4,9% of all opened emails). Cephalosporins are the most commonly used antibiotics for systemic prophylaxis in open fractures (cefazolin: 51,46% cefuroxime: 23,6%, ceftriaxone: 14,54%). In Gustilo type III open fractures gentamicin (49,12%) and metronidazole (33,58%) are often added. 86% (n=1033) reported to give the first dosage of systemic antibiotics in the emergency department as soon as the patient arrives. Only 3% (n=34) reported pre-hospital administration at the scene of the accident or during transport to the hospital. While most respondents administer antibiotics over 24h in type I open fractures (34%, n=405), for type II open fractures the most often mentioned duration is 72h (26%, n=306). For type III a 7 days course was most often performed (38%, n=448). Overall, there is a tendency to longer durations with increasing severity. However, a vast majority agreed that the optimal duration is not well defined in the literature (71%, n=849). 20psi,”Jet-Lavage”). The amount of irrigation fluid has a bimodal distribution with two peaks at 4–6 liters (24%, n=286) and at 8–10 liters (24%, n=282). Conclusions. Results from our survey give an overview of current practices and identify certain aspects in the management of open fractures where treatment protocols are very heterogenous and guidelines not well accepted. These controversies demand for further research in this field to provide better evidence

Introduction: Cephalosporins have traditionally been the preferred antimicrobial prophylaxis for 90% of orthopaedic surgeons. With a recent increase in Clos-tridium difficile and MRSA infections, antimicrobial prophylaxis is changing. The aim of this study was to conduct a national survey of current orthopaedic antimicrobial prophylaxis regimes. We wanted to ascertain whether there were any recent changes in these regimes and the reasons for these changes. We also aimed to show any relationship between antimicrobial usage and Clostridium difficile rates. Methods: Information on prophylaxis regimes and Clostridium difficile rates was requested through a five item questionnaire which was sent to all hospitals in the United Kingdom. Results: The response rate was 83 %. The top three antimicrobial regimes in trauma and elective orthopaedic surgery were cefuroxime alone (52 %), flucloxacillin plus gentamicin (18 %) and co-amoxiclav alone (8 %). Half of all hospitals had changed antimicrobial regimes and half of these changes were due to Clostridium difficile. The incidence of Clostridium difficile was 70% higher in hospitals using Cefuroxime than hospitals using other antibiotics (0.19% vs. 0.32%)(p < 0.001). Clostridium difficile infection was more common in trauma than elective surgery. Conclusion: Cefuroxime is still the most commonly used antimicrobial agent but its use has declined mainly due to a surge in Clostridium difficile rates. Reduction in cephalosporin use along with other infection control measures has resulted in a fall in Clostridium difficile infection rates

Antibiotic prophylaxis for joint replacement surgery is widely recommended and has been shown to reduce infection rates. Cephalosporins have commonly been used but are associated with development of Clostridium difficile associated diarrhoea (CDAD). The purpose of this study was to assess whether a change of protocol aimed at reducing CDAD, including a change of antibiotic prophylaxis would reduce rates of CDAD and other postoperative complications. We studied all 7989 patients in our trust that underwent hip or knee replacement from May 2002 to March 2009. These patients fell into two cohorts, firstly those who were prescribed cefuroxime as prophylaxis and secondly those prescribed gentamicin which was introduced following national concern regarding CDAD. Following the change of prophylaxis from cefuroxime 750mg three doses to gentamicin 4.5 mg/kg single dose the rate of CDAD reduced significantly (0.17% to 0%, p<0.03), however the rate of acute renal failure (0.29% to 0.6%, p=0.04) and pneumonia (0.71% to 1.38%, p<0.01) increased significantly. The rate of urinary tract infection (1.44% to 1.20%, p >0.05) and the overall return to theatre rate (1.86% to 2.30%, p=0.21) were not significantly changed. The spectrum of bacteria grown from infected joint replacements in the two cohorts was also analysed. The rate of deep MRSA infection was significantly less in the group given gentamicin. The frequency of other bacteria was also different between the cohorts, but not significantly so. We conclude that changing protocol including antibiotic prophylaxis in joint replacement patients can have the desired effect on a particular outcome namely CDAD but can also result in increased rates of other postoperative complications. It is also likely to result in a change in the bacterial spectrum of infected joint replacements

We set out to ascertain if there is a consensus in elective orthopaedic practice for the screening and management of MRSA. A questionnaire was distributed to all British Orthopaedic Association Linkmen, with prepaid return envelopes. A response rate of 60% (159 of 250) was recorded. 62% do have a screening policy in practice: all admissions (44%), high risk patients only (22%), only patients for joint replacement (12%), both patients for joint replacement and patients at high risk of carriage (21%). Eradication therapy is used in a MRSA - positive patient prior to joint replacement surgery by 91%, following which the MRSA status would be checked by 88%. The efficacy of eradication would be confirmed by obtaining: one set (29%), two sets (13%), and three sets (49%) of negative swabs, prior to proceeding with surgery. A 2nd generation Cephalosporin (77%), followed by Teicoplanin/Vancomycin (16%) are in routine use for antibiotic prophylaxis. The majority of responders have adopted a practice of screening patients; however, significant differences exist in the population that is selected for screening. Eradication in MRSA positive patients is a common practice, but there is variation in the number of subsequent screens performed. Cephalosporins remain the antibiotic of choice for prophylaxis but first line therapeutic agents are also being used which may have implications for resistance. These variations can be partly attributed to the lack of evidence from which practical guidelines can be drafted, as highlighted by national guidelines published in 1998. Until further research is done into the cost effectiveness of screening and the further management of MRSa we have to rely on strict adherence to infection control practices, and appropriate use of antibiotics

The use of sub-lethal doses of cell wall active antibiotics to induce cell wall deficiency in S aureus has been described. Cell Wall Deficient S aureus show an increased in-vitro ability to form biofilm. Cephalosporins(cell wall active antibiotics.) are commonly used at time of arthroplasty surgery as antimicrobial prophylaxis. Adherence is fundamental step in biofilm formation. The adherence of cell wall deficient S aureus versus ‘wild type’ S aureus to glass was investigated. Slides comparing the two types of organisms were analysed using fluoroscopy and J-image software. The ability to adhere to plastic was investigated using a micro-titre based absorption test. In a third investigation a centrifugal force was used to quantify the adherence ability of the cell wall deficient organisms to the glass slides. The cell wall deficient organisms demonstrated an increased ability to adhere to glass compared to the ‘wild type’. After exposure, there was on average twenty times more cell wall deficient organisms per unit area compared to the ‘wild-type’. The micro-titre plates were similar. After incubation, the absorption of each well was measured. Compared to the ‘wild type’ there was a significantly increased absorption in wells containing the cell wall deficient organisms. Showing an increased ability to adhere to plastic. The third technique quantified the ability to adhere using a centrifugal force. The slides were exposed to ‘wild type’ and cell wall deficient organisms, however before staining they were placed in a centrifuge. On analysis there were five cell wall deficient S aureus per field of view, compared to 0.5 ‘wild-type’. An increased ability of cell wall deficient S aureus to adhere to surfaces has been shown. Adherence is fundamental to biofilm formation. The significance to orthopaedics is that the inadequate use of Cephalosporins at time of operation may be facilitating chronic infections

Objectives

Thermal stability is a key property in determining the suitability of an antibiotic agent for local application in the treatment of orthopaedic infections. Despite the fact that long-term therapy is a stated goal of novel local delivery carriers, data describing thermal stability over a long period are scarce, and studies that avoid interference from specific carrier materials are absent from the orthopaedic literature.