Hand-mixed vancomycin versus commercial tobramycin cement revisited: A study on mechanical and antibacterial properties

Abstract

Arthroplasty-related infection has grown worldwide. Revision procedures for infection are associated with longer operating time, superior amounts of blood loss, and substantial economic encumbrance. To overcome cost, many surgeons opt for hand-mixed vancomycin into the bone cement. The objective of this research was to assess the biomechanical strength and antibacterial properties of hand-mixed vancomycin bone cement at different concentrations with commonly used industrial preblended antibiotic bone cement and plain cement. The target was to determine the ideal concentration of antibiotics that can be used in the preparation of hand-mixed vancomycin cement that delivers maximum antibiotics concentration without compromising its biomechanical properties. Materials and Methods: Vancomycinimpregnated polymethyl methacrylate (PMMA) specimen was hand prepared in varying concentrations (1-4 g). The authors tested three-point bending strength to determine 'maximum bending load' and stiffness and its antibacterial activity by looking into the zone of inhibition on methicillin-resistant Staphylococcus aureus-impregnated agar plate. These were compared with the industrial preblended Simplex™ P with 1 g tobramycin. Results: This study exhibited that vancomycin-PMMA disk that contained higher concentration of antibiotics had significantly higher antibacterial activity. The control group (plain cement) and industrial PMMA with preblended antibiotic (tobramycin) showed stable mechanical strength, while the hand-mixed antibiotic cement (HMAC) had variable mechanical strength varying on the concentration of antibiotics used. Conclusion: It was effectively concluded that HMAC is advantageous as a cement spacer; however, it is not recommended for primary arthroplasty and second-stage revision arthroplasty. The recommended maximum concentration of vancomycin based on this study is 2 g/pack (40 g) of cement. Industrial preblended antibiotic cement is superior to hand-mixed cement.

Effect of Physiological Fluids Contamination on Selected Mechanical Properties of Acrylate Bone Cement

“…Other bone cement additives that have been put to test are microhydroxyapatite, -magnesium oxide, -barium sulphate and -silica particles [15,36,37], as well as methacrylate crosslinkers ethylene glycol-dimethacrylate (EG-DMA) [15,57,58] or hydroxyethyl methacrylate (HEMA) [15,59], and finally, triethylene glycol-dimethacrylate (TEG-DMA) [15,60,61]. PMMA cement supplementation with vancomycin was assessed in the study by Ajit Singh et al [30], who concluded that even a 2 g addition of the drug per a 40 g container of cement (5% by weight) significantly affects the degradation of the three-point bending flexural strength. The antibiotic, supplemented in the form of a powder acts as an inclusion that causes stress build-up and as a result the weakening of the cement [30,62].…”

“…PMMA cement supplementation with vancomycin was assessed in the study by Ajit Singh et al [30], who concluded that even a 2 g addition of the drug per a 40 g container of cement (5% by weight) significantly affects the degradation of the three-point bending flexural strength. The antibiotic, supplemented in the form of a powder acts as an inclusion that causes stress build-up and as a result the weakening of the cement [30,62]. The study also tested the antibacterial properties of the antibiotic-supplemented cement: The increase in the amount of antibiotic in the mix, except for not contributing to any improvement in the bactericidal effectiveness, furthermore accelerated its mechanical degradation.…”

“…Based on the available data, the most common cause of revision surgeries is aseptic loosening, being responsible for 20% to 40% of procedures [29]. Revision procedures are the source of numerous disadvantages, including a longer operating time, greater blood loss, higher risk of complications, prolonged hospitalisation, multiple operations, increased hospital overhead costs and, above all, the discomfort of patients resulting from the need to return to outpatient departments, often for paid visits [30].…”

PMMA-Based Bone Cements and the Problem of Joint Arthroplasty Infections: Status and New Perspectives

“…Comparison between spacers loaded with the combination of gentamicin and vancomycin and spacers loaded with gentamicin alone has shown the higher antibacterial efficacy of the former. Finally, the antibiotic can be industrially blended into the pre-polymerized PMMA or can be manually added by a surgeon at the surgical site [17,51]. Figure 4 reports the trend of cumulative release of gentamicin-containing Palacos ® R + G (commercial sample) and Palacos ® R + GM (sample with gentamicin manually (M) added), together with the respective images of inhibition zones [16].…”

Antibiotic Choice: The Synergistic Effect of Single vs Dual Antibiotics

“…The utilization of antibiotic-laden cement (ALC), which delivers antibiotics directly into the joint, has become a common adjunct to treat and prevent PJI in arthroplasty patients [3]. Commercially available single antibiotic cements typically contain an aminoglycoside such as tobramycin to prevent infections by Gram negative organisms [4]. However, they have poor coverage of some Gram positive organisms, which comprise 86%-90% of all PJIs [5].…”