[Insufficiency fractures of the sacrum]

In two women aged 85 and 62 years respectively, with pain in the lower back and the hip region, insufficiency fractures of the sacrum were diagnosed. They were treated by bed rest and pain medication with good clinical outcome. Especially in older, postmenopausal women who have been treated for a malignancy (possibly with irradiation of the pelvis), the possibility of sacral insufficiency fractures should be kept in mind. Many unnecessary and sometimes invasive investigations to exclude tumour or metastases can be avoided by adequate diagnostic imaging: first conventional X-ray investigation followed by skeletal scintigraphy. A typical H-shaped pattern of sacral uptake is diagnostic of insufficiency fractures. As this pattern is seen in only approximately 20% of the patients, additional CT will often be necessary. CT can demonstrate the fracture lines and exclude bone destruction or a soft tissue mass. In case CT is not conclusive MRI is indicated.