apex distance

Objective To evaluate the therapeutic effects of dynamic hip screw ( DHS) on intertrochanteric fractures and discuss the relationship between tip apex distance ( TAD) and cutout of the screw.

目的评价动力髋螺钉（dynamic hip screw，DHS）治疗股骨转子间骨折临床效果，探讨头钉尖顶距（TAD）与头钉拔出的关系。

Methods A CT scanning was done for 30 adult cadaveric heads. The distance and angle of the lateral deviation from anterior nasal spine to the varial structures of the orbital apex, structures and the adjacent relationship of optic canal walls and the superior orbital fissure were measured.

方法随机选取30例成人尸头进行CT扫描，对前鼻棘至眶尖部各结构的距离、侧偏角、视神经管及眶上裂各径线长度、毗邻关系等进行断层影像解剖观测。

Of the moderate group: the above indexes, except for the apex decentration distance significantly decreased at12 months and more evidently at18 months.

中度组，除12个月时锥顶偏心距离、角膜散光值较配戴前无显著变化外，其他各项参数亦有明显降低，18个月时下降更为明显；

Results: ( 1) The distance from the arch apex of anterior semicircular canal to the surface of the petrous was 2.19 mm. The posterior semicircular canal was the nearest to groove for the sigmoid sinus.

结果：（1）前半规管拱峰离岩骨表面（弓状隆起）较浅，平均深2.19mm。