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Gentamicin release from commercially-available gentamicin-loaded PMMA bone cements in a prosthesis-related interfacial gap model and their antibacterial efficacy.

Neut D, Kluin OS, Thompson J, van der Mei HC, Busscher HJ - BMC Musculoskelet Disord (2010)

Bottom Line: All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases.Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one.These concentrations may be expected to effectively decontaminate the prosthesis-related interfacial gap directly after implantation, provided that these bacteria are sensitive for gentamicin.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands. d.neut@med.umcg.nl

ABSTRACT

Background: Around about 1970, a gentamicin-loaded poly (methylmethacrylate) (PMMA) bone cement brand (Refobacin Palacos R) was introduced to control infection in joint arthroplasties. In 2005, this brand was replaced by two gentamicin-loaded follow-up brands, Refobacin Bone Cement R and Palacos R + G. In addition, another gentamicin-loaded cement brand, SmartSet GHV, was introduced in Europe in 2003. In the present study, we investigated differences in gentamicin release and the antibacterial efficacy of the eluent between these four cement brands.

Methods: 200 μm-wide gaps were made in samples of each cement and filled with buffer in order to measure the gentamicin release. Release kinetics were related to bone cement powder particle characteristics and wettabilities of the cement surfaces. Gaps were also inoculated with bacteria isolated from infected prostheses for 24 h and their survival determined. Gentamicin release and bacterial survival were statistically analysed using the Student's t-test.

Results: All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases. SmartSet GHV showed a significantly higher burst release, while its sustained release was comparable with original Palacos. A gentamicin-sensitive bacterium did not survive in the high gentamicin concentrations in the interfacial gaps, while a gentamicin-resistant strain did, regardless of the type of cement used. Survival was independent of the level of burst release by the bone cement.

Conclusions: Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one. Overall, high gentamicin concentrations were reached inside our prosthesis-related interfacial gap model. These concentrations may be expected to effectively decontaminate the prosthesis-related interfacial gap directly after implantation, provided that these bacteria are sensitive for gentamicin.

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Gentamicin concentration as a function of time of exposure of a gap to 10 mL of phosphate buffered saline. The values are expressed as mean of three separate experiments, error bar denotes the average standard deviation.
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Figure 6: Gentamicin concentration as a function of time of exposure of a gap to 10 mL of phosphate buffered saline. The values are expressed as mean of three separate experiments, error bar denotes the average standard deviation.

Mentions: The patterns of cumulative gentamicin release from the cement into the bulk fluid, are shown in Figure 6. Besides differences in the cumulative amounts of gentamicin released, differences are also seen in the kinetics of gentamicin release. The release of gentamicin from SmartSet GHV and Refobacin Palacos R increases somewhat less after prolonged release than from Palacos R + G and Refobacin Bone Cement R. Gentamicin release from Refobacin Bone Cement R and Palacos R + G is significantly more rapid, statistical significant increase (p < 0.05), than the release of gentamicin from SmartSet GHV and Refobacin Palacos R. After 1 week 8.6 ± 0.6%, 12.2 ± 0.8%, 12.5 ± 3.6%, 3.6 ± 0.4% of the total gentamicin content of a sample block was released for the Refobacin Palacos R, Refobacin Bone Cement R, Palacos R + G, and SmartSet GHV, respectively.


Gentamicin release from commercially-available gentamicin-loaded PMMA bone cements in a prosthesis-related interfacial gap model and their antibacterial efficacy.

Neut D, Kluin OS, Thompson J, van der Mei HC, Busscher HJ - BMC Musculoskelet Disord (2010)

Gentamicin concentration as a function of time of exposure of a gap to 10 mL of phosphate buffered saline. The values are expressed as mean of three separate experiments, error bar denotes the average standard deviation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992479&req=5

Figure 6: Gentamicin concentration as a function of time of exposure of a gap to 10 mL of phosphate buffered saline. The values are expressed as mean of three separate experiments, error bar denotes the average standard deviation.
Mentions: The patterns of cumulative gentamicin release from the cement into the bulk fluid, are shown in Figure 6. Besides differences in the cumulative amounts of gentamicin released, differences are also seen in the kinetics of gentamicin release. The release of gentamicin from SmartSet GHV and Refobacin Palacos R increases somewhat less after prolonged release than from Palacos R + G and Refobacin Bone Cement R. Gentamicin release from Refobacin Bone Cement R and Palacos R + G is significantly more rapid, statistical significant increase (p < 0.05), than the release of gentamicin from SmartSet GHV and Refobacin Palacos R. After 1 week 8.6 ± 0.6%, 12.2 ± 0.8%, 12.5 ± 3.6%, 3.6 ± 0.4% of the total gentamicin content of a sample block was released for the Refobacin Palacos R, Refobacin Bone Cement R, Palacos R + G, and SmartSet GHV, respectively.

Bottom Line: All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases.Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one.These concentrations may be expected to effectively decontaminate the prosthesis-related interfacial gap directly after implantation, provided that these bacteria are sensitive for gentamicin.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands. d.neut@med.umcg.nl

ABSTRACT

Background: Around about 1970, a gentamicin-loaded poly (methylmethacrylate) (PMMA) bone cement brand (Refobacin Palacos R) was introduced to control infection in joint arthroplasties. In 2005, this brand was replaced by two gentamicin-loaded follow-up brands, Refobacin Bone Cement R and Palacos R + G. In addition, another gentamicin-loaded cement brand, SmartSet GHV, was introduced in Europe in 2003. In the present study, we investigated differences in gentamicin release and the antibacterial efficacy of the eluent between these four cement brands.

Methods: 200 μm-wide gaps were made in samples of each cement and filled with buffer in order to measure the gentamicin release. Release kinetics were related to bone cement powder particle characteristics and wettabilities of the cement surfaces. Gaps were also inoculated with bacteria isolated from infected prostheses for 24 h and their survival determined. Gentamicin release and bacterial survival were statistically analysed using the Student's t-test.

Results: All three Palacos variants showed equal burst releases but each of the successor Palacos cements showed significantly higher sustained releases. SmartSet GHV showed a significantly higher burst release, while its sustained release was comparable with original Palacos. A gentamicin-sensitive bacterium did not survive in the high gentamicin concentrations in the interfacial gaps, while a gentamicin-resistant strain did, regardless of the type of cement used. Survival was independent of the level of burst release by the bone cement.

Conclusions: Although marketed as the original gentamicin-loaded Palacos cement, orthopaedic surgeons should be aware that the successor cements do not appear to have the same release characteristics as the original one. Overall, high gentamicin concentrations were reached inside our prosthesis-related interfacial gap model. These concentrations may be expected to effectively decontaminate the prosthesis-related interfacial gap directly after implantation, provided that these bacteria are sensitive for gentamicin.

Show MeSH
Related in: MedlinePlus