The goal of the proposed study is to develop a treatment for accelerating multiple vertebral fracture repairs. Approximately 10 million people in the United States are diagnosed as osteoporotic, while an additional 34 million are classified as having low bone mass. The lifetime incidence of fragility fractures secondary to osteoporosis in females over the age of fifty years of age is approximately 1 in 2, and in males over the age of fifty, is 1 in 4. Vertebral compression fractures (VCFs) are the most common fragility fractures in the United States, accounting for approximately 700,000 injuries per year, twice the rate of hip fractures. Approximately 70,000 VCFs result in hospitalization each year with an average hospital stay per patient of 8 days. Current treatment of osteoporotic patients is mostly focused on prevention of VCFs mainly using new medicines such as Alendronate and Parathyroid Hormone (1-34). But there are a few options of treatment when VCFs actually occur. New, non-biological, methods have been developed to regain the biomechanical properties of a fractured vertebral body. These methods include the minimally invasive procedures of vertebroplasty and balloon tamp reduction. Both procedures involve injection of synthetic nonbiological material that does not resorb and instead remains a permanent foreign-body fixture in the spine. Ultimately, a biological solution that would promote rapid fracture healing and stimulate normal bone production would be the best for osteoporotic patients with vertebral column injuries. Our pilot studies have shown that bone fractures can be treated by intravenous administration of adult stem cells combined with a dose of parathyroid hormone, which is approved by the FDA for use as an anabolic agent in the treatment of severe osteoporosis. Therefore, in the proposed project we will determine the ability of injected stem cells to migrate to a vertebral fracture site. We will also analyze the combined effect of PTH and stem cells on vertebral fracture repair.