A medical device for treating hip joint osteoarthritis in a human patient by providing at least one artificial hip joint surface is provided. The hip joint having a ball shaped caput femur as the proximal part of the femoral bone with a convex hip joint surface towards the centre of the hip joint and a bowl shaped etabulum as part of the pelvic bone with a concave hip joint surface towards the centre of the hip joint. The medical device comprises the artificial hip joint surface comprising at least one of； an artificial caput femur or an artificial caput femur surface comprising, a convex form towards the centre of the hip joint, and an artificial acetabulum or an artificial acetabulum surface comprising, a concave form towards the centre of the hip joint. The artificial convex caput femur or the artificial convex caput femur surface is adapted to be fixated to the pelvic bone of the human patient and the artificial concave acetabulum or artificial concave acetabulum surface is adapted to be fixated to the femoral bone of the human patient.
