A Research Of Chronic Osteomyelitis Treatment With Vancomycin-loaded Calcium Phosphate Cement

Background:The treatment of Osteomyelitis and prosthesis infection is the most troublesome problem of surgeons. At present, the treatments of osteomyelitis include resection and debridement of the infected bone, an early antibiogram-specific therapy, and repair the defect area of the bone. The gold standard therapy is the implantation of polymethylmethacrylate(PMMA) as spacer and local antibiotic carrier. Although the usage of PMMA has achieved a certain clinical effect, Lots of disadvantages limit its development.Calcium phosphate cement(CPC),which has a chemical composition close to bone and has the merit of not heating up during polymerization of cement, has been paid more attention. CPC can be used as a better bone filler and drug carrier.But none studies have shown the differents of physicochemical characterization and the rule of the drug release of CPC loading different proportion vancomycin.Our study aims at revealing which proportion of VCM that CPC loading has the best proporty of physical and chemical and has a better release of VCM in vitro offering a guidance for clinical treatment. Methods:Specimens of calcium phosphate cement loading different proportions of vancomycin(0%,5%,10%, 15%,20%,25%, 30%,35%,40% CPC/ VCM) were prepared. The solidifying times, compressive Strength, rule of Elution and micro structure were evaluated. Result:The TI prolonged when the the ratio of VCM was below twenty percent(includes 5%10%,15%,20%),compared with the control group. Howerer, the TI was significantly shortened and the polymer was very dry when the ratio of VCM was over twenty percent.The compressive strength of CPC gradually decreased with the increase of the ratio of antibiotics. When the ratio of antibiotics exceeded 30%, the compressive strength of the CPC was lower than that of the normal cancellous bone(11MPa).The Elution test showed 5% and 10% group showed a more stable and effective drug release rule.The microscopic images showd that CPC transformed into crystalline state and and VCM transformed into amorphous state. Conclusion:The 10% VCM/CPC not only meet the clinical requirement of mechanical strength,but also can maintain a longer drug release time and effective local concentration.