A disc prosthesis for vertebrae is provided. The disc prosthesis comprises a first plate, a first insert, a second plate, and a second insert. The first plate comprises a first active face and a first anchor face. The second plate comprises a second active face and a second anchor face. The first anchor face is configured to anchor the first plate to a first vertebra. The second anchor face is configured to anchor the second plate to a second vertebra. The first plate comprises a cavity for receiving the first insert. The cavity comprises a concave spherical cap. The second plate comprises an opening that connects the second active face to the second anchor face. The second insert comprises a fastener portion, said fastener portion is friction fit in the opening.