A kit for use in arthroplasty. The kit including a shell which has a shell locking section. The kit further including a liner adapted to be inserted into the shell. The liner includes an inner surface and an outer surface, wherein the inner surface is generally concave. The outer surface is adapted to engage the shell, and includes a liner locking section and a curved section. The curved section has a radius. The shell locking section and the liner locking section are adapted to engage one another. The shell locking section and the liner locking section are self-locking tapers. The curved section extends tangentially from the liner locking section at a first transition point.
