股骨头钻孔液氮冷冻法建立山羊股骨头坏死模型

A goat model for femoral head osteonecrosis established via liquid nitrogen freezing after femoral head drilling

[目的]研究通过股骨头钻孔液氮冷冻法建立山羊股骨头坏死模型。[方法]12只山羊24髋随机法分配为实验组、对照组。实验组山羊采用股骨头钻孔液氮冷冻灌注法灌注山羊股骨头,对照组山羊采用股骨头钻孔灌注生理盐水法,术后80万IU青霉素连续抗感染3 d,干预2周后行影像学检查,分别行X线、三维CT、大体标本、组织学(HE染色)观察骨结构改变及空骨陷窝率,空骨陷窝率超过50%定义为骨坏死。[结果]山羊手术后完全苏醒后可完全负重站立行走。术后3 d山羊活动、饮食恢复至术前水平。术后山羊伤口干燥,未见明显渗血渗液以及炎症反应等。术后2周山羊X线及三维CT示:实验组股骨头骨小梁稀疏、钻孔通道周围可见明显骨质硬化;对照组骨小梁正常,钻孔通道周围未见骨质硬化。处死山羊后实验组与对照组标本大体形态未见明显改变,但实验组股骨头关节面软骨颜色变暗、光泽度下降。组织切片HE染色提示对照组空骨陷窝率(11.3±1.6)%<50%,实验组空骨陷窝率(59.2±5.2)%>50%,空骨陷窝率实验组明显高于对照组(P<0.05)。股骨头坏死造模成功率91.67%(11/12)。[结论]股骨头钻孔液氮冷冻法可以成功建立山羊股骨头坏死模型,此法安全、简单易行、周期短、造模成功率高,为进一步研究股骨头坏死保头治疗提供有力的途径。

[Objective]To establish a goat model for femoral head osteonecrosis by injecting liquid nitrogen into the femoral head through a drilled tunnel. [Method]Twenty- four hips of 12 goats were randomly divided into 2 groups,namely the experimental and control groups. In the experimental group,liquid nitrogen was injected in the femoral head through a hole drilled into it. In the control group,we used normal saline instead of liquid nitrogen. After surgery,800 000 IU of penicillin was continuously administered for 3 days to prevent infection in both groups. All the goats were killed after performing imaging tests 2 weeks after surgery. The bone structure of the goats was observed by performing radiography and 3- dimensional computed tomography（ CT） of gross specimens. The bone lacuna vacuity rate was determined via histological examination（ hematoxylin- eosin[HE]staining）. Osteonecrosis was defined as a bone lacunae vacuity rate of 〉 50%. [Result]After surgery and after the effect of the anesthesia had worn off,all the goats were capable of full weight- bearing standing and walking. The goats recovered normal activity and diet at the third postoperative day. In both groups,the wounds were dry,without exudates and inflammation,throughout the observation period. The radiographic and 3- dimensional CT images obtained at 3 postoperative weeks showed that in the experimental group,the bone trabeculae in the femoral head were thinning and bone sclerosis surrounded the drilled tunnel,whereas in the control group,the bone trabeculae in the femoral head were normal and no bone sclerosis surrounded the drilled tunnel.The experimental and control groups had no significant differences,except darkening and reduced glossiness were observed in the femoral head articular surface of the cartilage of the goats in the experimental group. On the basis of the HE staining results,the bone lacunae vacuity rate was 59. 2% ± 5. 2%（ 〉 50%）in the experimental group and 11. 3% ± 1. 6%（ 〈 50%） in the control group,indicating a significantly higher value in the experimental group（ P 〈 0. 05）. This femoral head osteonecrosis model had a molding success rate of 91. 67%（ 11 /12）. [Conclusion]This method of using liquid nitrogen freezing after femoral head drilling successfully established a goat model for femoral head osteonecrosis. The method is safe,simple,and less time- consuming,with a relatively high successrate. This method should be further studied to develop strategies for femoral head preservation in the treatment of femoral head osteonecrosis.