Acute sacroiliitis as a manifestation of calcium pyrophosphate dihydrate crystal deposition disease.

While radiographic lesions of the sacroiliac joint (SIJ) are common in patients with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, they are rarely accompanied by clinical symptoms. We report the case of a 69-year-old woman who presented with an acute sacoiliitis and a linear calcification in the right SIJ on CT scan. The patient recovered well after intra-articular steroid injections.