Hip joint device and method

A medical device for implantation in a hip joint of a human patient, a natural hip joint having a ball shaped caput femur as a proximal part of a femoral bone with a convex hip joint surface towards a center of the hip joint and a bowl shaped acetabulum as part of a pelvic bone with a concave hip joint surface towards the center of the hip joint, wherein the ball shaped caput femur has a centrally located length axis, extending through a center of the ball shaped caput femur and a collum femur and being aligned with the collum femur, defined as a center axis of the ball shaped caput femur and the collum femur, the medical device comprising;

• an artificial caput femur comprising a convex surface adapted to face towards the center of the hip joint, wherein said artificial caput femur is adapted, when implanted, to be fixated to the pelvic bone of the human patient by a pelvic fixation element;
• a bowl shaped artificial acetabulum comprising a concave surface adapted to face towards the center of the hip joint, wherein said bowl shaped artificial acetabulum is formed and sized to, when implanted,
• a. be fixated to the femoral bone of the human patient, and
• b. be in movable connection with the artificial caput femur to allow functional hip movements,
• and
• a locking member comprising a locking surface adapted to be in direct or indirect contact with an outer surface of the artificial caput femur, wherein said locking member comprises a femur fixating portion adapted to fixate the bowl shaped artificial acetabulum to the femoral bone, and stabilizing it by cortical bone of the femoral bone of the patient, from an outside of the femoral bone.