2008三医大 WJ Chen Sacroiliac joint △ 1. pelvis Pubic Obturator mem symphysis Formation hip bone Obturator canal sacrum Sacrotuberous lig Sacrospinous lig 亲 Joints: joints and ligaments 后面观 前面观 152008三医大 WJ Chen 15 1.pelvis Formation ：hip bone， sacrum Joints ：joints and ligaments 后面观 前面观 Sacroiliac joint Pubic symphysis Sacrotuberous lig. Sacrospinous lig. Obturator mem. Obturator canal