[Sacral insufficiency, unexpected clinical entity as a cause of low back pain. Report of two cases].

BACKGROUND: sacral insufficiency fractures are a cause of debilitating pain in the elderly. These fractures were first described as a clinical entity in 1982. The bone in these patients is structurally weakened and often associated with diseases such as osteoporosis, cancer and immunological processes. This translates into back and pelvic pain unrelated to trauma. These fractures are usually caused by fatigue in most cases. Bone scans and MRI are the imaging studies with the most sensitivity for detecting sacral insufficiency.

CLINICAL CASES: two patients with sacral insufficiency fractures who were studied by MRI and bone scan, in whom the diagnosis of sacral insufficiency was made, were treated by sacroplasty.

CONCLUSIONS: sacral insufficiency is an underdiagnosed disease, caused by wide range of diseases, mainly osteoporosis. The studies of choice for diagnosis are MRI and bone scans. Techniques, such as percutaneous sacroplasty, produce significant improvements in pain scores and seem a suitable alternative for managing this disease.