A spine prosthesis is provided and in particular, related to the facet joint of a spine. A spinal implant comprises a facet prosthesis including an insert to be positioned within a joint capsule between facets of a zygapophyseal joint. The insert may comprise a member having two opposing facet interfacing portions. A facet prosthesis exerts a distraction force between facets of a facet joint and may comprise a curable material to be injected into the facet joint. A facet prosthesis may also comprise a pair of magnets, each magnet coupled to a facet and oriented with like poles facing each other to provide a distracting force away from each other. A spine implant may also include an insert to be positioned within the joint capsule, a securing member comprising an elongate portion extending through part of a facet, and an anchor to anchor the securing member to the facet.