Teoman Atıcı1, Namık Şahin2, Sinan Çavun3, Cüneyt Özakin4, Tufan Kaleli1

1Department of Orthopedics and Traumatology, Uludag University, Faculty of Medicine, Bursa, Turkey
2Department of Orthopedics and Traumatology, Konya Training and Research Hospital, Konya, Turkey
3Department of Medical Pharmacology, Uludag University, Faculty of Medicine, Bursa, Turkey
4Department of Medical Microbiology, Uludag University, Faculty of Medicine, Bursa, Turkey

Keywords: Antibiotic elution; bone cement; infected arthroplasty; spacer.


Objectives: This study aims to compare the antibiotic release and biological effectiveness of bead type and articulating spacers of different cement types with antibiotics added at alternative phases of cement preparation. Materials and methods: Four gram vancomycin was added into two types of antibiotic-free cement (Simplex®, Biomet®) with similar viscosity and also gentamycin-containing cement (Refobacin®). Prepared specimens were used to create cement beads and articulating hip spacers, making a total of six different groups. Two alternative groups were formed by adding the Vancomycin while the cement was in dough phase. Antibiotic release and biological activity were evaluated with immunoassay techniques and agar-disk diffusion methods.
Results: All groups showed initial antibiotics surge in the first week, which was 2 to 4 times more evident in the beads group. Antibiotic release and change in release rate were significantly different between Simplexalternative and Simplex, Biomet, Refobacin-beads, and between Biometspacer and Refobacin-beads groups (p<0.05). Elution of antibiotics was not different between mobile spacers prepared with conventional or alternative methods (p>0.05). Biomet cement showed larger diffusion inhibition zone in agar. There was no difference between biological activity of the bead and mobile designs of the Biomet brand (p>0.05). Inhibition zone analyses of agar and disk diffusion tests revealed significant differences between several groups (p<0.05).
Conclusion: Cement beads provide superior antibiotic release regardless of cement type or preparation method. Simplex P® cement has lower anti-bacterial efficiency than Biomet®. Different methods for cement and antibiotics mixing and addition of extra vancomycin into the commercially drug loaded cement do not have any effect on the results.