A composition having a hydrogel bearing side of a biostable polymer network, wherein the biostable polymer network comprises a first gradient of the biostable polymer, which biostable polymer network decreases in concentration from the hydrogel bearing side to a bone interface surface； and a second gradient of a biostable polyurethane network, which polyurethane network increases in concentration from the hydrogel bearing side to the bone interface surface, the bone interface surface useful for an orthopedic implant.
