We present a novel surgical robotic system for spinal fusion that includes a computer-based planning algorithm, O-type bi-planar fluoroscopy, and a surgical robot. The planning system determines a surgical path based on fluoroscopy images or a 3D image reconstructed using pre-operative CT data. The robot guides the surgical path that the surgeon generates with the planning system. In this cadaver study, we tested the performance of the robotic system in the treatment of eight lumbar vertebrae by comparing CT images recorded before and after surgery.