Disuse osteoporosis is a condition characterized by bone loss due to a lack of stress or pressure on the bones. It is due to lack of usage of the arm or leg. It can occur postoperatively in patients who are non weight bearing or who must immobilize the extremity to allow healing. Chemotherapy may cause osteoporosis worse. Radiation can lead to bone necrosis that can also weaken the bone. Due to the weakened nature of the bone, the risk of fracture is increased. A bone mineral density (BMD) exam can be used to assess bone density and diagnose osteoporosis.