Objective To study the influence of excision of sacrum through the superior and inferior margins of the 1st to 3rd posterior sacral foramina on area of sacroiliac joint surface.

目的研究经第1~3骶后孔上、下缘水平切除骶骨对骶髂关节面面积的影响。

Because of the penetrative foramina of the soleplate incorporated the movable door with the open framework, it is very convenient to close the penetrative foramina of the soleplate.

由于床板上的贯穿孔结合活动门，活动门有开启机构，不但能封闭床板上的贯穿孔，而且操作方便。