Hydrophilic interpenetrating polymer networks derived from hydrophobic polymers

An orthopedic implant device, said implant device comprising:

• a composition comprising two or more polymer networks having a hydrogel bearing side of a polymer network, wherein the polymer network comprises a first gradient of the polymer, which polymer network decreases in concentration from the hydrogel bearing side to a bone interface surface;
• and
• a second gradient of a polyurethane network, which polyurethane network increases in concentration from the hydrogel bearing side to the bone interface surface, the bone interface surface of the polyurethane network comprises an osteochondral graft, wherein the orthopedic implant device is a cartilage replacement prosthesis.