“人”位、动力蛙式位及传统蛙式位固定对幼兔股骨头及骺板软骨凋亡实验研究

Experimental study of cartilage apoptosis of the femoral head and epiphyseal plate with Λ position,dynamic frog and traditional frog-leg position fixation in immaturity rabbits

[目的]幼兔双髋行"人"位、动力蛙式位及传统蛙式位固定,探讨对股骨头及骺板软骨细胞凋亡影响。[方法]44只3周龄幼兔随机分4组(n=11):"人"位组(A组),动力蛙式位组(B组),传统蛙式位组(C组)及正常对照组(D组),固定3周后处死取股骨头。采用HE染色观察股骨头及骺板软骨细胞组织形态,免疫组化检测软骨bcl-2、bax蛋白表达情况。[结果](1)HE示A、B、C实验组股骨头表面软骨不光滑,细胞柱状紊乱,层次不清,细胞数量减少,基质染色不均匀,纤维组织增多;对照组软骨表面光滑,细胞柱状排列整齐规则,数量多,基质染色均匀;(2)免疫组化示股骨头关节软骨A、B、C实验组bax表达强度均显著高于对照组(P<0.05),对照组bcl-2/bax比值最高,动力蛙式位组bcl-2/bax比值显著高于传统蛙式位组和"人"位组(P<0.05);股骨头骺板软骨对照组和动力蛙式位组肥大、增殖区细胞bcl-2/bax比值显著高于传统蛙式位和"人"位组(P<0.05),静止区各组之间无显著差异(P>0.05)。[结论]3种髋固定体位均能影响股骨头及骺板软骨细胞凋亡,其中,传统蛙式位及"人"位固定加速软骨细胞的凋亡,不利于细胞存活,而动力蛙式位固定能抑制或延缓凋亡,促进细胞存活,对股骨头发育相对有利。

[ Objective] To explore the effect of apoptosis in chondrocytes of the femoral head and epiphyseal plate induced by the fixation of A position,dynamic frog and traditional frog- leg position in immaturity rabbits. [ Method] A total of 44 rabbits with only 3 weeks were randomly divided into 4 groups （ n = 11 ） ： A position group （ group A）, dynamic frog position group （ group B）, frog - leg po- sition group （group C） and the blank control group （group D）. Then we excuted the rabbits and took the femoral heads when fixed re- spectively at 3 weeks. The histomorphology of the chondrocytes of femoral head and epiphyseal plate were observed by HE staining method ,the changes of bax and bcl -2 expression were detected by immunohistochemistry method. [ Result] （1）On HE staining,the ar- ticular cartilage surface became rough and the chondrocytes lost normal column structure, and the extracellular matrix became uneven and covered fibrous tissue in the experimental groups A, B, C. However, the articular cartilage showed smooth surface and the chondro- cytes appeared regular columnar arrangement,and the extracellular matrix staining was uniform in the control group. （2） On immunohis- tochemistry,the expression of the bax in groups A,B,C were significantly more than in the control group （P 〈0. 05）. The bcl -2/bax ratio in the control group was significantly higher than in the other groups （P 〈 0. 05）, and was significantly higher in dynamic frog group than in the A position and traditional frog -leg position （P 〈 0. 05 ）. At hypertrophic zone and proliferative zone of the femoral ep- iphyseal plate cartilage, the bcl -2/bax ratio in the control group and dynamic frog group were significantly higher than in the A posi- tion group and traditional frog - leg position group （ P 〈 0. 05）. The bax and bcl - 2 expression in the stationary zone were not statistical-ly significant different among the 4 groups （P 〉 0. 05 ）. [ Conclusion]The apoptosis of the chondrocytes of the femoral head and epiphysea[ plate could be affected by the three immo- bilizational position in rabbits＂ hip. Among them, apoptosis was increased and the survival was hindered in the A position group and traditional frog - leg position group. However, apoptosis was inhibited or delayed and the survival of chondrocytes was promo- ted,and was relatively favorable for the develooment of femorathead in dynamic frog position group.