Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Helfrich, J.
Manual addition of antibiotics to PMMA bone cement: Effects on mechanical and microbiological properties
Humanmedizin; [ Diplomarbeit ] Medical University of Graz; 2019. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Kühn Klaus-Dieter
- Leithner Andreas
- Altmetrics:
- Abstract:
- Introduction: Use of antibiotic loaded acrylic bone cement (ALABC) represents an effective adjuvant treatment option when combating periprosthetic infection. There are few antibiotics available for local delivery, particularly when gram-negative bacteria are present. The objectives of our study were to evaluate the mechanical properties as well as the bio-activity of different PMMA bone cements after manual addition of 4 different antibiotic powders. Materials and Methods: Meropenem, imipenem, fosfomycin trometamol and calcium fosfomycin were admixed to the cement powder and subsequently combined with the liquid monomer to create antibiotic-loaded PMMA-cements. These cements were used to fashion standardized molds for testing. ALABC-cylinders were immersed in sterile phosphate-buffered saline (PBS) solutions and incubated at 37°C. At pre-determined points aliquots of the eluate were extracted for testing. The cylinders were then transferred into fresh tubes with PBS. The bio-activity of the eluates was tested against Escherichia coli (clinical strain), MRSA ATCC 43300, Pseudomonas aeruginosa ATCC 27853 and Proteus mirabilis ATCC 12453 for a period of 42 days. Mechanical properties, including compressive strength, flexural strength, flexural modulus as well as impact resistance were determined via standardized tests according to ISO 5833 and DIN 53435 standards. Results: All antibiotics were easy to mix into the cement powder and each yielded a homogenous dough. All the ALABCs met the criteria defined by the International Organization for Standardization (ISO) with the sole exception of calcium-fosfomycin which had a detrimental effect on impact and bending strength. Meropenem-impregnated cements proved particularly effective against E. coli as well as Pseudomonas aeruginosa throughout the measuring period. Imipenem-loaded cements were found to be biologically active against MRSA over a period of two weeks. Fosfomycin trometamol proved to be more effective than calcium fosfomycin against Proteus mirabilis. Discussion: It is easy to amalgamate pulverulent antibiotics with acrylic bone cement. The mechanical properties were impaired by 2g of calcium fosfomycin, however this effect did not occur with carbapenems. On the basis of the present study, the use of meropenem, imipenem and fosfomycin trometamol in spacers can be recommended as it represents an effective treatment option for periprosthetic infection particularly in the presence of gram-negative bacteria.