Antibiotic bone cement as a form of prophylaxis against deep infection for total hip joint replacements is widely used; however its efficacy has not been proven. This study aims to determine if the use of prophylactic antibiotic cement for primary total hip joint replacements in New Zealand reduces the risk of deep infection requiring revision. Data from January 1999 to December 2007 were recovered from the New Zealand National Joint Registry. Proportional hazards regression analysis was used to study the relative revision risks or failure rates between those THJR which utilised antibiotic bone cement and those using plain bone cement. Of the 32,646 hips included in the study 1376 were revised. The overall use of antibiotic and plain cement through this time period is relatively equal, with 18,863 (54.7%) receiving ABC compared to 16,295 (46.3%) hips receiving plain cement. The presence of antibiotics in bone cement was not found to affect whether the hip went on to get revised for deep infection (p =0.16). Nor was the type of operating theatre (p=0.13), the use of space suits (p=0.97), and the operative time (p=0.55). Younger age was found to be the most significant indicator for the need for revision for infection (p value 0.00014). The induction of antibiotic resistance and the significant additional costs associated with antibiotic bone cement cannot be denied. While the literature supports the prophylactic use of antibiotic bone cement for patients at high risk of infection, the routine use in patients who have a low risk of infection may not be justified

Aim. To evaluate the ability of different combinations of antibiotic loaded cement to inhibit bacteria growth and biofilm formation. Method. Cement beads were aseptically prepared using Palacos R (plain 40g PMMA cement) or Palacos R+G (40g PMMA cement containing industrially added 0.5g of gentamicin), with or without supplementary antibiotics as follows: Palacos R; Palacos R+G; Palacos R plus 1g / 2g daptomycin; Palacos R+G plus 1g / 2g of daptomycin; Palacos R plus 1g / 2g vancomcyin; and Palacos R+G plus 1g / 2g vancomycin. After production, each antibiotic loaded acrylic cement (ALAC) combination was allocated into two groups (group 1 and 2). The group 2 cement beads were initially eluted in broth at 37. o. C for 72hours then transferred to fresh broth containing a known concentration of bacteria. The group 1 samples were not eluted but directly immerse in culture broth containing bacteria. All samples were thereafter incubated at 37. o. C for 24 hours. After incubation, group 1 samples were visually assessed for bacterial growth, while for the group 2 samples, biofilm formation were quantified using ultrasonication and viable bacteria counting technique. Three proficient biofilm forming Staphylococcus epidermidis bacterial strains (1457, 1585-RA and 5179-R1) were used for all experiments and the bacteria counts were expressed as colony forming units / ml (CFU/ml). Results. In the group 1 samples, all the ALAC combinations were able to inhibit growth of all the three biofilm bacteria strains assessed except the gentamicin only samples in which biofilm growth were observed within 24hours. Meanwhile, in group 2, bacterial growth and biofilm formation by all three bacterial strains were observed on all the ALAC combinations, with the least biofilm formation being on the Palacos R+G plus 2g daptomycin combinations (mean CFU/ml: 1.04E +06) and the greatest on the gentamicin only cement (mean CFU/ml: 2.3E +07). Conclusions. Our study demonstrates that the highest antimicrobial activity of ALAC is seen in the first 24 hours. However, after 72 hours of antibiotic release, fresh bacterial exposure in fresh broth resulted in varying degrees of biofilm colonisation of all ALAC surfaces. Nonetheless, the overall biofilm formation was least on the gentamicin / daptomycin combinations and the results were statistically significant when compared to plain cement (p < 0.05, two tail t-test)

The removal of cement debris at the time of primary and revision joint replacement has been facilitated through the introduction of coloured bone cements. Up to date, few studies have evaluated the effect of methilene blue dye on physical, mechanical and pharmacological properties of cements. In this light, we evaluated the effects of adding methylene blue to bone cement with or without antibiotics (gentamicin, vancomycin or both). The addition of methylene blue to plain cement significantly decreased its mean compression (95.4±3 MPa vs 100.1±6 MPa, p = 0.03) and bending (65.2±5 MPa vs 76.6±4 MPa, p < 0.001) strengths, mean setting time (570±4 seconds vs 775±11 seconds, p = 0.01), as well as its mean elastic modulus (2744±97 MPa vs 3281±110 MPa, p < 0.001). Bending resistance decreases after the supplementation of the coloured cement with vancomycin and gentamicin (55.7±4 MPa vs 65.2±5 MPa, p < 0.001). The release of antibiotics from the bone cement was significantly decreased by the methylene blue. Indeed, the release of gentamicin alone was 385.5±26 μg in comparison to 228.2±24 μg when the methylene blue was added (p < 0.001), while the release of gentamicin in combination with vancomycin was 613±25 μg vs 498.5±70 μg (p = 0.018) when the dye was added to the same formulation. With this study we demonstrated several theoretical disadvantages of the antibiotic-loaded bone cement coloured with methylene blue, although caution should be exercised in transferring our findings to the clinical context. Based on our findings, we do not recommend methylene blue supplementation of PMMA for routine clinical use

Introduction:. Deep infection after total joint arthroplasty is a devastating complication with reported incidence of 1–3% with projection to increase to 6.8% by 2030. The direct costs of revision surgery due to septic failure are estimated at over $55,000 per case. Antibiotic-Loaded Bone Cement (ALBC) has been proposed as a preventive measure to decrease post-operative infection rates. Its efficacy has been compared with plain bone cement (PBC) in multiple studies. There has been no study to our knowledge examining its efficacy in “high risk” patients. The purpose of this study is to compare infection rates in three cohorts of patients: (1) all patients receiving only PBC, (2) all patients receiving only ALBC, and (3) only “high risk” patients receiving ALBC. Methods:. A standard cement protocol was instituted at our hospital for primary total knee arthroplasties (pTKA). From January 2000 to 2005 all pTKAs were performed with PBC. From February 2005 to May 2010, all pTKAs were performed with ALBC. From June 2010 to March 2012, all patients received regular bone cement unless they had previous diagnoses of rheumatoid arthritis, obesity, and/or diabetes mellitus. Our institutional joint registry was queried and the three cohorts' individual charts were retrospectively reviewed. Infection rates amongst cohorts were compared at 30 days, 6 months, and 1 year from index surgery date utilizing two sided proportion tests. Results:. A total of 3,292 consecutive primary TKAs with full follow up were included. Overall infection rate at one year for the entire study was 0.76%. There were 1,025 patients who received PBC, 1486 ALBC, and 781 in the risk stratified cohort. The 30-day infection rates for cohorts 1, 2, 3 were .0.29%, 0.20%, and 0.13% respectively. The 6-month infection rates for cohorts 1, 2, 3 were 0.39%, 0.54% and 0.38% respectively. The 1-year infection rate for cohorts 1, 2, 3 were 0.78%, 0.61%, and 0.64% respectively. The differences in infection rates between each cohort at all three time intervals were not statistically significant. Conclusions:. Antibiotic loaded bone cement does not significantly decrease infection rates for primary total knee arthroplasty. Even risk stratified usage of ALBC for “high risk” patients may be unnecessary and add undue costs to both the patient and hospital, without any appreciable benefit

Implant-associated infection is a major source of morbidity in orthopaedic surgery. There has been extensive research into the development of materials that prevent biofilm formation, and hence, reduce the risk of infection. Silver nanoparticle technology is receiving much interest in the field of orthopaedics for its antimicrobial properties, and the results of studies to date are encouraging. Antimicrobial effects have been seen when silver nanoparticles are used in trauma implants, tumour prostheses, bone cement, and also when combined with hydroxyapatite coatings. Although there are promising results with in vitro and in vivo studies, the number of clinical studies remains small. Future studies will be required to explore further the possible side effects associated with silver nanoparticles, to ensure their use in an effective and biocompatible manner. Here we present a review of the current literature relating to the production of nanosilver for medical use, and its orthopaedic applications.

Cite this article: Bone Joint J 2015; 97-B:582–9.