Fig 2.

Fluoroscopic (A, C) and corresponding volume-rendered 3D reconstructions of CT images (B, D) of a hemisacrum from a single cadaveric pelvis, demonstrating anatomic landmarks for needle placement (arrow in image C indicates needle) and PMMA injection before (A, B) and after (C, D) sacroplasty. The sacrum is shown in a left posterior oblique orientation (A–D), with the beam manipulated parallel to the L5-S1 disk space¹ and ipsilateral sacroiliac joint.³ Fluoroscopy (C) and CT (D) demonstrate PMMA within the superior-lateral sacral ala in an area bounded by the following: first, a line connecting the lateral edge of the posterior foraminal openings,² and second, a line superimposed on the medial edge of the sacroiliac joint.³