微波加热制作股骨头坏死模型:最适宜的温度和时间筛选

背景:目前股骨头坏死模型还不能很好地模拟临床股骨头坏死情况,利用微波灭活提供了一种新的方法,但是其具体的标准尚未确定.目的:探讨微波灭活制作股骨头坏死模型的适宜温度和时间.方法:将48只大白兔按数字随机法分为4组,将微波天线插入兔股骨头,4组分别以不同的时间(10,20 min)和温度(50,55,60℃)进行股骨头微波灭活,灭活后即刻、1,2,4,8和12周,观察兔行为、利用X射线、MRI检测股骨头影像,并观察股骨头切片的组织坏死及修复情况.结果与结论:50℃ 10 min条件微波灭活1周后,部分兔股骨头骨髓组织凝固变性,8周时坏死骨小梁及骨髓组织完全吸收.55℃10 min微波灭活1周后,兔股骨头骨髓组织凝固,2周时股骨头出现T1相信号减低、T2相信号增高区,4周时坏死与修复同时进行,12周时骨修复停止,骨坏死继续,股骨头开始塌陷.50℃ 20 min和60℃ 10 min微波灭活8周后,所有兔股骨头塌陷变形.由此认为,采用55℃ 10 min微波灭活股骨头是制作兔股骨头坏死模型的适宜温度和时间,其股骨头变化符合临床病理变化过程.

Inducing a femoral head necrosis model by microwave heating:Screening of optimal temperature and time

BACKGROUND:The existed femoral head necrosis(FHN)model can not reflex the clinical necrosis of femoral head correctly.Microwave heating provides a new approach for model preparation.but the concrete standard remains uncertain.OBJECTIVE:To study the optimal temperature and time jn preparing a FHN model induced by microwave heating.METHODS:Totally 48 rabbits were randomly divided into 4 groups on the basis of the microwave temperature(50,55,60℃)and heating time(10,20 minutes).The microwave antenne was inserted into the rabbit femoral head.The rabbits were sacrificed immediately and at 1,2,4,8 and 1 2 weeks after operation.A series of examinations were performed including gross observation,X-ray.histology and MRI to observe the femoral head necrosis and repair status.RESULTS AND CONCLUSION:Marrow partially solidified in the group(50℃,10 minutes)at 1 week,and the osteonecrosis returned to normaI at 8 weeks after operation.1n the group(55℃,10 minutes),marrow was completely coagulated at 1 week and low signal on T1 weighted images and increased signal on T2 images were identified at 2 weeks.Osteonecrosis and repair occurred at the same time at 4 weeks.At 12 weeks,the osteonecrosis continued and the repair stopped,and the femorel heads started to collapse.All femoral heads collapsed at 8 weeks in group(50℃,20 minutes)and group(60℃,10 minutes).Accordingly.microwave heating is a good method in developing FHN model.55℃ and 10 minutes are the optimal temperature and time for the development of FHN model of rabbits induced by microwave heating.