Osteoporosis. Computer artwork of a human female skeleton degenerating due to osteoporosis. At left is a normal skeleton. The degeneration, seen from left to right over time, is the loss of height and the backwards curvature (kyphosis) of the spine. Osteoporosis is a condition where loss of bone mass causes a reduction in the bone density. Shown in the background is the structure of a monoclonal human immunoglobulin (IgG2a) antibody. Under the name of Denosumab this type of human monoclonal antibody is used for the treatment of osteoporosis, decreasing the risk of fractures and increasing bone density. Medication trade names include Prolia and Xgeva.