A comparasion of antibiotic release between a cement scaffold, a perforated cement scaffold and a cement scaffold mixed to calcium sulphate: in vitro study

One of the most dangerous possible complications in joint replacement is infection due to bacteria adhere to prosthesis surface making biofilm difficult to erase. The gold standard treatment consists in prosthesis removal, placement of antibiotic-impregnated cement spacer and systemic antibiotics therapy. When the infection heals a new prosthesis is implanted. The antibiotic-impregnated spacer is important to maintain the prosthesis space and to guarantee a local high concentration of antibiotics. The release of the antibiotic by the cement happens at its surface so that, increasing this, the concentration of antibiotic should be increased as well. The aim of the present study is to verify the different release of antibiotic in plasma by different groups of scaffolds to identify the best solution to make the antibiotic spacer in septic prosthesis revision. Six groups of three antibiotic impregnated cement cube-shaped have been done. The first, made by only antibiotic and cement, the second by a double concentration of the antibiotic and cement, the third made by the antibiotic cement and perforated in every surface with a needle before hardening, the fourth similar to the previous but with a double concentration of antibiotic, the fifth by antibiotic-impregnated cement mixed with calcium sulphate pellets, the sixth similar to the previous with a double concentration of antibiotic. The cubes were immersed in plasma and the concentration of antibiotic released valued at specific times. The perforated cement scaffold demonstrated the best result during the first four weeks.