A spinal disc prosthesis comprises an upper rigid plate, a lower rigid plate, and an elastomeric core interposed between the plates and adhered to the plates. The elastomeric core has an upper portion with an outer peripheral surface extending substantially perpendicular to the upper plate. A lower portion of the elastomeric core has an outer peripheral surface extending substantially perpendicular to the lower plate. An intermediate portion of the elastomeric core, extending between the upper and lower portions, has a concave outer peripheral surface. Each of the upper and lower plates has a plurality of ribs extending into the elastomeric core to secure the elastomeric core to the upper and lower plates.