Conclusions PTSF method is the most rigid way of sacral fixation,anterointerior sacral promontory method is the second,and anterolateral sacral wing method is the worst.

• 结论PTSF法骶骨螺钉的抗拨出力和摆动力矩最大，固定最坚强，前内骶岬方向骶骨螺钉次之，前外骶翼方向骶骨螺钉固定最差。