#$%^&*AU2018200035B220190711.pdf#####ABSTRACT A medical device for implantation in a hip joint of a human patient, the natural hip joint having a ball shaped caput femur as the proximal part of the femoral bone with a convex hip joint surface towards a central location of the hip joint between the caput femur and the acetabulum and a bowl shaped acetabulum as part of the pelvic bone with a concave hip joint surface, the medical device comprising; an artificial caput femur, comprising a convex surface, wherein said artificial convex caput femur is adapted to, when implanted, be immovably fixated to the pelvic bone of the human patient, and be in movable connection with an artificial acetabulum surface fixated to the femoral bone of the patient, thereby forming a ball and socket joint, wherein the medical device further comprises a fixation element connected to said artificial convex caput femur and configured to be fixated to the abdominal side of the pelvic bone.