An implant is insertable onto a vertebral facet joint includes a body with an inner surface that mates with one or both articular processes of the facet joint. The inner surface may define an interior cavity that accepts at least a portion of an inferior articular process and a superior articular process forming the facet joint. The body may be constructed of a bone growth material that fuses with the articular processes. The implant may help retain bone growth promoting substance that is inserted between or on articulating surfaces of the facet joint. A receiving portion of an exterior surface of one or both articular process may be prepared to stimulate bone growth. The implant may be placed onto the receiving portion to cover an exterior junction between or on the articulating surfaces of the facet joint. The implant may be secured to one or both of the articular processes.