[Pelvic lytic lesion, and the need to suspect osteoporosis-related fractures]

Insufficiency fractures of the pelvis may be overlooked as a cause of hip or groin pain. These fractures occur in the elderly, usually those with pronounced osteopenia of the pelvis. Predisposing factors include corticosteroids, local irradiation and postmenopausal osteoporosis. These fractures are difficult to detect clinically and plain radiographs and other studies may be misleading, delaying diagnosis and treatment. A 65-year-old woman had left groin and hip pain for 2 months with no history of trauma. Plain radiographs showed lytic lesions in the left pubic rami. Bone scan revealed increased uptake in that region, suggesting metastatic bone disease. Computed tomography and magnetic resonance imaging demonstrated fractures in the left superior and inferior pubic rami, with callus formation with no involvement of soft tissues. Quantitative computed tomography indicated low calcium concentration, below fracture threshold. The diagnosis of insufficiency fractures of the pelvis was confirmed by the favorable clinical and radiographic outcome. It is therefore important to be familiar with the appearance and location of these fractures.