A medical device for treating hip joint osteoarthritis by providing a joint surface is provided. The medical device has at least two artificial hip joint surface parts adapted to be connected to each other to form an artificial hip joint surface during an operation. A method of treating a hip joint of a human patient by providing the medical device is also provided. The method includes cutting the skin of the human patient, dissecting an area of the pelvic bone on the opposite side from the acetabulum, creating a hole in the dissected area passing through the pelvic bone and into the hip joint and providing the medical device to the hip joint, through the hole in the pelvic bone.
