Insufficiency fractures of the acetabulum (the hip socket that the thigh bone fits into) occur due to decreased strength of the acetabular bone. If the fracture is isolated to the acetabulum, the condition may be difficult to identify due to nonspecific symptoms such as sudden incapacitating hip pain, groin pain, and back pain. Subchondral edema, which is collection of fluid just below the cartilage, may occur as a reaction to cartilage breakdown and other micro-traumatic changes. Plain X-rays may not show any significant findings and an MRI scan may be necessary to confirm the diagnosis. Most patients respond well to conservative treatment if the insufficiency fracture of the acetabulum is detected early. This consists of bed rest, analgesics, and physical therapy. If conservative measures fail to provide relief, surgical fracture fixation may be necessary.