The older the patient the higher the risk, i.e., as high as 20 percent in the over 70 age group. Other insufficiency fractures of the pelvis that are not so easily identified are the insufficiency fractures of the sacrum and acetabulum. These fractures can go unrecognized, leading to occult fracture causing serious complications.
Pain radiating down one leg is often an associated complaint.
Many times a patient will have a history of steroid therapy, radiation therapy or rheumatoid arthritis. Steroid and radiation therapy both cause osteonecrosis and accelerate the changes associated with osteoporosis. Rheumatoid arthritis is almost always associated with osteopenia due to the hyperemia caused by the inflammation and pannus formation, which slowly destroys the joint. Often, these patients will already have compression fractures involving the spine due to the osteoporosis. The two areas in the pelvis that are predisposed to insufficiency fractures that are commonly missed are the supra-acetabular fracture and the sacral fracture.