| Background.Chronic osteomyelitis is the disease with complex, long duration, bonedefects and easy to relapse, their treatment has been a problem for orthopedicsurgeons. According to the pathological changes of chronic osteomyelitis andtreatment principles, orthopedic surgeons made a lot of effort about thedebridement, topical antibiotic application methods, the bone defect repair.Topical polymethylmethacrylate (PMMA) cement carrier releasing high dosesof antibiotics along with systemic antibiotic therapy, is a standard method ofthe treatment of chronic osteomyelitis. However, polymethylmethacrylatewith cement polymerization process of heating, need to take out thedisadvantage of secondary surgery. Recently, the calcium phosphate cement(CPC) has been used as bone substitutes and amplification, and no fever in thepolymerization process, no effect on the active of the pharmaceutically. Thedrug concentration and time difference released from the calcium phosphatecement (CPC) loaded vancomycin (VCM) and the polymethylmethacrylate(PMMA) loaded vancomycin (VCM), domestic research is still not clear.Aim.Contrast the drug concentration and the effective time between calciumphosphate cement (CPC) loaded with vancomycin (VCM) and polymethylmethacrylate cement (PMMA) loaded with vancomycin (VCM), providingthe experimental basis for clinical application.Methods.Test specimens consisted of a powder composite of CPC or PMMA, VCM and solvent (5:0.25:1.6g). Each test specimen was immersed in sterilephosphate-buffered saline (PBS). Replacing soaking liquid every24hours,saving the specimens eluent from the first day, the third day weekly and lastingfor8weeks. Determination of the concentration of vancomycin in the soakingsolution by high performance liquid chromatography (evaluative HPLC).Results.The concentration of VCM eluted from CPC/VCM was maximal on day1,then decreased precipitously but continued to elute for at least53days. As theminimum inhibitory concentration (MIC) for MRSA is0.78–3.13g/ml,Concentrations of VCM that were above the MIC were eluted from CPC/VCMup to53days at least.The concentration of VCM eluted from PMMA/VCM was maximal on day1,then decreased precipitously but continued to elute for39days. Concentrationsof VCM that were less than the MIC were eluted from PMMA/VCM in36days.The elution concentration of calcium phosphate cement/vancomycincomplex in the first day is1.30times as great as polymethylmethacrylate/vancomycin complex,the first week was1.37times,1.96times for the secondweek,the third week3.12times,3.93times for the fourth week,the fifth weekaround6.30times. The periods of VCM from CPC/VCM and PMMA/VCMabove the MIC were53days,36days respectively.Conclusions.Compared with polymethylmethacrylate, CPC could release more VCM over alonger period, is ideal drug delivery for the treatment of chronic osteomyelitis. |
