Abstract: A spinal disk implant is implanted between vertebrae of the human spine following discectomy. The implant comprises a solid body having four sides and a pair of spaced-apart, opposed bases. The four sides include spaced-apart, opposed anterior and posterior faces, and a pair of spaced-apart, opposed transverse faces. Each transverse face has an anterior platform adjacent to the anterior face. The anterior platform is spaced apart from the opposed anterior platform by a maximum anterior platform spacing. A posterior ledge is oriented at an insertion angle relative to an opposed posterior ledge of the opposed transverse face. At least one of the posterior ledges has a pattern of serrations. There is a ridge on at least one of the transverse faces, positioned between the anterior platform and the posterior ledge and extending in the direction perpendicular to the bases. The top of the ridge is spaced apart from the opposed transverse face by an amount greater than the anterior platform spacing.