A method for implantating a medical device in a hip joint of a patient is provided. The medical device is adapted to be fixated to the pelvic bone of the patient, and comprises an inner and an outer surface, a contacting portion of the inner surface is spherical and adapted to face the center of the hip joint when said medical device is implanted, and said medical device is adapted to receive a caput femur or a prosthetic caput femur having a spherical portion. The medical device comprises at least one extending portion adapted to clasp the caput femur, or prosthetic caput femur, for restraining said caput femur, or prosthetic caput femur in said medical device. The medical device is adapted to release the caput femur or prosthetic caput femur from the medical device when a predetermined strain is placed on the medical device. The ability of the medical device to release the caput femur or prosthetic caput femur from the medical device when a predetermined strain is placed on the medical device reduces the risk that the prosthesis is loosened by an abnormal strain being placed on the hip joint from e.g. the patient falling or making a rapid movement of the hip.

A medical device for implantation in a hip joint of a patient. The medical device comprises an inner and an outer surface, wherein a contacting portion of said inner surface is spherical and adapted to face a center of the hip joint when said medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic caput femur having a spherical portion. Said medical device comprises at least one extending portion adapted to clasp the caput femur, or prosthetic caput femur, for restraining said caput femur, or said prosthetic caput femur in said medical device. The extending portion comprises an elastic portion, and the medical device is adapted to release the caput femur or prosthetic caput femur from said medical device by deflecting said at least extending portion when a predetermined strain is placed on said medical device by abnormal movement of the hip joint caused by the patient.

A medical device for implantation in a hip joint of a patient. The medical device comprises an inner and an outer surface, wherein a contacting portion of said inner surface is spherical and adapted to face a center of the hip joint when said medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic caput femur having a spherical portion. Said medical device comprises at least one extending portion adapted to clasp the caput femur, or prosthetic caput femur, for restraining said caput femur, or said prosthetic caput femur in said medical device. The extending portion comprises an elastic portion, and the medical device is adapted to release the caput femur or prosthetic caput femur from said medical device by deflecting said at least extending portion when a predetermined strain is placed on said medical device by abnormal movement of the hip joint caused by the patient.

A medical device for implantation in a hip joint of a patient is provided. The medical device is adapted to be fixated to the pelvic bone of the patient. The medical device comprises an inner and an outer surface, a contacting portion of the inner surface is spherical and adapted to face the center of the hip joint when said medical device is implanted, and said medical device is adapted to receive a caput femur or a prosthetic caput femur having a spherical portion. The medical device comprises at least one extending portion adapted to clasp the caput femur, or prosthetic caput femur, for restraining said caput femur, or prosthetic caput femur in said medical device. The medical device is adapted to release the caput femur or prosthetic caput femur from the medical device when a predetermined strain is placed on the medical device.

A medical device system for implantation in a hip joint for providing at least one artificial hip joint surface for a patient is disclosed. The medical device system comprises an artificial acetabulum surface being at least partly bowl-shaped. The artificial surface comprises a largest cross-sectional distance being variable such that the medical device system can be inserted through a hole in the pelvic bone, from the abdominal side of the pelvic bone, the hole having a diameter smaller than said largest cross-sectional distance. Finally, the artificial acetabulum surface comprises at least two parts which are adapted to be interconnected to form an interconnected medical device when in use.