FIG 1. Case 1, a 76-year-old woman with low back pain.

A, Pelvic radiograph shows degenerative lumbar changes. Note, however, that the sacrum is unremarkable.

B, Bone scan shows the H sign diagnostic of a sacral insufficiency fracture. Prominent renal activity on the scan is a normal finding.

C, Cortical disruption (arrows) on a non-contrast-enhanced pelvic CT scan confirms fracture.

D and E, Anteroposterior (D) and lateral (E) fluoroscopic images show cement in the L4 vertebral body and cement bilaterally in the sacral ala. The lateral view illustrates the difficulty with visualization within the sacrum during this technique.

F, Postoperative pelvic CT scan shows cement within the bilateral superior sacral ala in the vicinity of the fracture lines

G, Follow-up pelvic radiograph shows the cement within the superior sacrum