An implant is provided for performing spinal fusion. The implant includes an implant body having a leading side and a trailing side at opposing ends along a longitudinal axis. Between the leading side and trailing side are an upper surface, a lower surface, an anterior side, and a posterior side. At least one keel structure is provided extending from the implant body for penetration into an adjacent vertebral body. A trial sizer and keel cutter may be utilized to form keel channels within the vertebral body to receive the keel structure.