动脉机械性阻断致股骨头缺血性坏死的实验研究

目的　通过分别阻断股骨头主要供血血管 ,观测股骨头血流动态改变、血管再生及病理改变 ,为临床选择不同方法治疗股骨头缺血性坏死提供参考。方法　将实验兔旋股内、外侧动脉 ,根据不同组别分别结扎。于术后不同时间应用SPECT检测患侧头与健侧头、患侧头与干放射性计数比 ,半定量动态检测股骨头血流量及代谢的改变 ;拍X线平片 ,对股骨头墨汁染色切片 ,硬组织切片及荧光染色切片进行观察 ,并进行骨组织形态计量学检测 ,评价预后。结果　结扎旋股内、外侧动脉组及结扎旋股内侧动脉组的头 /头比及头 /干比明显下降 ,X平片示股骨头密度增高 ,切片荧光反映明显 ,骨组织形态计量学检测显示骨小梁结构紊乱 ,两组间无显著性差异 (P >0 0 5 ) ;结扎旋股外侧动脉组的头 /头比及头 /干比轻度下降 ,比值增高不显著 ,X线平片示股骨头无改变 ,切片荧光反映不明显 ,骨组织形态计量学检测显示骨小梁形态无明显变化 ,与前两组之间均有显著性差异 (P <0 0 5 )。墨汁染色切片示三组股骨头均有密集的血管 ,各组间无显著差异。结论　旋股内侧动脉及其分支为股骨头主要供血动脉 ;当股骨头血供受损严重 (头 /头比 <0 7,(参考头 /干比 <1 8) ],并呈持续高代谢反应时 ,骨小梁承受应力能力差 ,后期出现塌陷可能性大

Study of avascular necrosis of the femoral head caused by mechanical occlusion of artery

Objective To observe the dynamic changes of blood flow,revascularization and pathology by ligating different blood vessels,and to provide references for treating avascular necrosis of femoral head.Methods The wall and the lateral femoral circumflex arteries of rabbits were ligated according to different requirements in groups. The radioactive ratios of ill femoral head to healthy femoral head and ill femoral head to the ipsilateral shaft in rabbits were measured by SPECT at the different time points after operation to detect blood flow and metabolism. X-rays, undecalcified slices stained with toluidine blue and labeled with tetracycline, decalcified slices stained with ink were observed. Bone histomorphometry was measured to evaluate the prognosis. Results There was significant reduction in the ratio of ill head to healthy head and ill head to shaft in the groups with both arteries ligated and with only the wall femoral circumflex artery. The femoral heads showed the persistent hypermetabolic change and the ratio was high. Density of the femoral heads was high under X- rays and there was distinct deposition of tetracycline.The structure of bone trabeculae was complicated. No significant difference was found between the two groups(P>0.05). On the contrary,the ratio of the group ligated the lateral femoral circumflex artery decreased insignificantly. X-rays showed no change or distinct tetracycline deposited. Bone histomophometry showed no obrious change in bone trabeculae. Significant differences were found between this group and the other two groups(P<0.05). Slices stained with ink showed regular regeneration of blood vessel of all groups withcat significant difference(P>0.05). Conclusion Wall femoral circumflex ard is the main blood vessels supplying the femoral head.When blood flow decreased significantly (ratio of head to head decreased to 0.7 and ratio of head to shaft decreased to 1.8), the ability of the bone trabeculae for weight bearing is low and subsequent collapse likely.