Effect of Lattice Structures on the Antibiotic Release from Bone Cement: In Vitro Study

Background. Local therapy aimed to suppress infection of the osteoarticular apparatus is based on the use of coated spacers. As a rule, the coating surfaces are composed of bone cement supplemented with bioactive substances, e.g., antibiotics. However, current approaches aimed to stimulate the release of antibiotics from bone cement are not always effective and may even decrease their properties and biological activities. The aim of the study — to examine the effect of the lattice structures of base implants on the dynamics and amount of antibiotics released from bone cement in vitro. Methods. A novel type of implants with a lattice structure and traditional reinforced spacer filled with bone cement and antibiotic were used in present study. The release of vancomycin and cefazolin was measured spectrophotometrically for up to 30 days. Calibration curves were made according to the regression lines based on the values of the stock solutions with the well-known concentrations of the antibiotics. Results. For all tested samples, the elution profile of antibiotics was determined and illustrated the significant release of the drugs during the initial time-period followed by the decrease (day 7) and reaching a uniform elution plateau (day 15). In all samples, the amount of released antibiotic did not exceed 1% of total amount of the drug present in the implant. Notably, the higher release of the antibiotics was found for the samples with lattice structure when compared with control group, despite the relatively higher initial amount of bone cement and antibiotics in control samples. A difference in the amount of antibiotics was also detected between the tested samples of two types of lattice structures. Conclusion. The lattice structure of the implants increases the amount of antibiotic release from the bone cement and also facilitates the antibiotic dynamics release when compared to the traditional bone cement used as the reinforced spacers.