As one of the newer osteoporosis drugs, parathyroid hormone, or teriparatide, known under the brand name Forteo, has had success rebuilding bone. Researchers have now showed that it may also be able to preserve and even regenerate cartilage whose destruction is behind crippling osteoarthritis, projected to afflict more than 50 million Americans by 2020. Both conditions negatively impact quality of life, limiting mobility and, with osteoporosis, putting patients at greater risk of life-threatening bone fractures. "Right now physicians have no way to bring back cartilage in patients who have lost it to osteoarthritis," said Randy Rosier, MD, PhD, professor within the Department of Orthopaedics and Rehabilitation at the University of Rochester Medical Center. "Our current results, at least in mice, show that we can inhibit cartilage degeneration and improve the volume of cartilage in diseased joints. It’s remarkable enough that this compound delays the loss of cartilage, but these results show it also may be able to restore, at least to some extent, cartilage in already degraded joint surfaces. In the near future, we hope this serves as the foundation of new treatments that restore function to long injured joints, perhaps staving off joint replacement surgeries for some years." Rosier and his team will next seek to confirm the durability of the effect in further animal studies and look for funding from the National Institutes of Health to begin pilot clinical studies of PTH treatment of osteoarthritis in people possibly by 2010.