Twenty percent of people over age 70 suffer from fractures caused by weakening of bones from osteoporosis. Most of us are well aware of stress fractures that involve the femoral neck and pubic bones. Other stress fractures involving the pelvis are not so easily identified, but they are not uncommon. These fractures involve the sacrum and acetabulum. They can go unrecognized, leading to occult fractures and causing serious complications.
Pain radiating down one leg is often an associated complaint.
The patient will often 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 hyperemia caused by inflammation and pannus formation, which slowly destroys the joint. Often these patients already have compression fractures involving the spine due to osteoporosis. The two areas in the pelvis that are predisposed to stress fracture and are commonly missed are the supra-acetabular region and the sacral region.