含庆大霉素羟基磷灰石涂层假体控制关节置换术后感染的实验研究

The effect of hydroxyapatite-coating prosthesis combined gentamicin on the control of infection after total joint arthroplasty

目的评价含庆大霉素羟基磷灰石（hydroxyapatite，HA）涂层假体控制关节置换术后感染的效果。方法采用仿生溶液法制备含庆大霉素HA涂层假体，在体外实验中检测庆大霉素的释放情况。将50只中国白兔分成5组，每组10只，第1组植入HA假体，第2组带菌植入HA假体，第3组带菌植入含庆大霉素HA假体，第4组带菌植入HA假体并肌内注射庆大霉素，第5组带菌植入含庆大霉素HA假体并肌内注射庆大霉素。手术当天及术后第28天拍摄左胫骨X线片，进行评分；术前、术后第3、7、14、21、28天检测血常规、红细胞沉降率、肛温和体重；术后第28天处死动物，对髓腔和假体进行细菌培养，对骨标本进行组织学观察。结果含庆大霉素HA涂层假体在体外释放庆大霉素可达到金黄色葡萄球菌的最低抑菌浓度，并可持续10d以上。第1组无感染，第2组全部感染，第3组6只感染，第4组6只感染，第5组3只感染。第2、3组体温比第4、5组高；影像学评分、血常规、红细胞沉降率和体重各项组间比较差异均无统计学意义；细菌菌落数比较，第2组〉第4组〉第3组〉第5组。结论含庆大霉素HA涂层假体能够和全身应用抗生素协同，较好地控制局部感染。

Objective To assess the effect of the prosthesis coated with hydroxyapatite （HA） combined with gentamicin on preventing infections after arthroplasty. Methods Examining the concentration and the time of gentamicin released from the prosthesis. Fifty Chinese white rabbits were divided into five groups averagely, All rabbits in each group were processed according to the experimental designs. The rabbits were taken X-ray examination on the operation day and the postoperative 28th day on the left tibia and radiological assessment was done. Blood routine examination, erythrocyte sediment rate （ESR）, body temperature and weight were examined before the operation and on the 3rd, 7th, 14th, 21st, 28th day after the op- eration. Microbiological examination was done both on the bone and the prosthesis at the 28th days postop- eratively. Calculating the clonal formation unit （CFU） number if there is colony emerging from the blood culture medium. And histology inspection was also done on the samples. Results The gentamicin released from the prosthesis with gentamicin-HA coating could reach the minimum inhibition concentration （MIC） of the staphylococcus and could persist for more than 10 days in vitro. There was no infected rabbit in group 1, 10 in group 2, 6 in group 3, 6 in group 4 and 3 in group 5. The mean body temperature of group 2 and group 3 is higher than that of group 4 and group 5; there is no significant difference among the groups in terms of radiological assessment, blood routine examination, ESR and weight. The CFU number of bacteria cultured both from marrow cavity and prosthesis in group 2 is higher than that of group 4 which is higher than that of group 3 and group 5, while group 3＇s is higher than that of group 5. Conclusion The gentamicin released from the prosthesis with gentamicin-HA coating could reach the MIC of the staphylococcus and could persist for more than 10 days in vitro. The prosthesis with gentamicin-HA coating could locally help to reduce infection at a certain extent in collaboration with general antibiotics.