PROJECT ABSTRACT The long-term objective of this project is to improve the care of patients suffering from osteoporotic compression fractures, which occurs in up to 700,000 US patients per year. These painful fractures are a leading cause of back pain-related morbidity and mortality. Historically these fractures were treated with bed rest, bracing, and narcotic analgesics. The advent of spine augmentation, i.e., the percutaneous injection of medical cement into painful fractures, in the 1990s has been considered a watershed event in the care of these patients. The procedure, done either as a simple needle infusion (termed “vertebroplasty”) or with temporary balloon inflation (termed “KKyphoplasty”), has been shown in numerous case series to offer remarkable relief of pain. Unblinded randomized controlled trials (RCTs) of both vertebroplasty and Kyphoplasty confirmed these earlier results, showing benefit of spine augmentation over medical therapy. However, four independent, blinded, placebo controlled trials of vertebroplasty no benefit of over a “simulated” procedure without cement infusion. Unlike vertebroplasty, Kyphoplasty has never been evaluated in a blinded trial. In the aftermath of the “sham” vertebroplasty trials, the number of vertebroplasty procedures performed in the US plummeted, while Kyphoplasty procedures have actually increased over time. Numerous investigators have proposed that Kyphoplasty is superior to vertebroplasty, but numerous RCTs comparing the two procedures have shown relative equivalence in outcomes. As such, it remains unknown whether Kyphoplasty would offer benefit over a "simulated" augmentation, where vertebroplasty did not. In this grant application, we will make plans to carry out a future randomized, controlled trial of Kyphoplasty versus a “control intervention,” where Kyphoplasty is simulated but no cement infused. This type of study design will allow us to determine whether the observed benefit of Kyphoplasty is related to the balloon inflation and cement infusion or to other factors that include patient expectation of benefit (i.e., the “placebo effect”).