Lumbar spinal fusion is commonly performed in humans but the failure rate of bone union is reported to range from 5-36%. Recently, osteoinductive growth factors synthesized by recombinant DNA technology have been shown to induce bone formation in heterotopic sites. Recombinant human BMP-2 (rhBMP-2) has been effective in generating spine fusions in a rabbit model. To determine the appropriate dose of the growth factor for human use and to determine the speed of healing, a non-human primate model has been chosen. Higher doses than expected were required to make bone in the primate, but it was successful. The growth factor was successfully delivered inside a hollow titanium threaded fusion cage through a minimally invasive approach. Studies in the following year will focus on the precise dose and exploring alternative carrier materials that will better bind the growth factor. These studies are critical to providing the information needed for the next step which is hu man clinical trials. This treatment, if successful, will significantly impact on the care of spine patients and prevent multiple surgeries in the 5-35% of patients who do not heal their spine fusion on the first attempt. P51RR00165-36 1/1/1996 - 12/31/1996 Yerkes Regional Primate Research Center