A system includes a constrained acetabular insert, a dual mobility liner, and a femoral head. The constrained acetabular insert has its perimeter extending beyond hemisphere and the dual mobility liner has its perimeter extending beyond hemisphere and configured to tilt and rotate within the constrained acetabular insert. The femoral head is configured to tilt and rotate within the dual mobility liner. The constrained acetabular insert may include a plurality of tabs and the dual mobility liner may include screw threads for receiving the plurality of tabs.

Dual mobility hip prosthesis has a liner rim that recessed with respect to an acetabular cup rim thereof so that an adjacent contact surface of the neck impinges the acetabular cup rim at extreme positions without impinging the liner rim. Furthermore, the acetabular cup rim defines an inner contact face correspondingly angled to the adjacent contact surface of the neck at the extreme positions to reduce point contact loading between the acetabular cup rim and the adjacent contact surface of the neck. As such the present prosthesis tolerates prosthetic impingement between the rim of the acetabular cup and the neck of the femoral component by mitigating against point contact loading force whilst eliminating impingement of edges of the polymeric liner between an edge of the neck and the rim of the acetabular cup and also allowing for sufficiently deep acetabular componentry with reduced likelihood of dislocation.

A medical device for implantation in a hip joint of a patient; the hip joint having a caput femur integrated with a collum femur having a collum and caput center axis, extending longitudinal along the collum and caput femur, in the center thereof. The medical device comprises an elongated portion adapted to at least partially replace the collum femur, wherein said elongated portion is adapted to be at least one of integrated in and connected to a prosthetic spherical portion adapted to replace the caput femur, and wherein said prosthetic spherical portion in turn is adapted to be movably placed in a prosthetic replacement for the acetabulum having at least one extending portion for clasping said prosthetic spherical portion. Said elongated portion comprises a restricting portion adapted to restrict the motion range of the spherical portion in relation to said prosthetic replacement for the acetabulum. Said restricting portion of said elongated portion comprises at least one recess adapted to receive a portion of said prosthetic artificial acetabulum, when implanted, to enable an advantageous motion range in relation to said prosthetic replacement for the acetabulum.

A system includes a constrained acetabular insert, a dual mobility liner, and a femoral head. The constrained acetabular insert has its perimeter extending beyond hemisphere and the dual mobility liner has its perimeter extending beyond hemisphere and configured to tilt and rotate within the constrained acetabular insert. The femoral head is configured to tilt and rotate within the dual mobility liner. The constrained acetabular insert may include a plurality of tabs and the dual mobility liner may include screw threads for receiving the plurality of tabs.

The invention relates to a joint prosthesis having a shaft made from a titanium alloy, in which at least the shaft is investment cast and has a body-centered cubic crystal structure. A titanium alloy having this crystal structure (known as -titanium alloy) has an advantageously low modulus of elasticity which is well matched to the physiological demands of joint prostheses. Furthermore, implementation as a shaped casting allows a complex shape to be achieved. It is particularly embodied as a femoral prosthesis for an artificial hip joint, which has an elongate shaft with grooves and sawtooth-like projections for bone anchoring.

A medical device for implantation in a hip joint of a patient is provided. The medical device comprises a first and second piece and a releasing member adapted to, in a first state hold the first piece attached to the second piece, and in a second state release the first piece from the second piece. The releasing member is adapted to change from the first state to the second state when a pre-determined strain is placed on the releasing member.

A medical device for implantation in a hip joint of a patient is provided. The hip joint has a caput femur integrated with a collum femur having a collum and caput center axis, extending longitudinal along the collum and caput femur, in the center thereof. The medical device comprises an elongated portion adapted to at least partially replace the collum femur. The elongated portion is adapted to be connected to a prosthetic spherical portion adapted to replace the caput femur. The prosthetic spherical portion in turn is adapted to be movably placed in a prosthetic replacement for the acetabulum comprising at least one extending portion adapted to clasp said prosthetic spherical portion. The elongated portion comprises a restricting portion adapted to restrict the motion range of the spherical portion in relation to said prosthetic replacement for the acetabulum. The restricting portion of the elongated portion is adapted to enable an advantageous motion range in relation to said prosthetic replacement for the acetabulum.

An anchor for securing an implant within bone. In one embodiment, the anchor is used to aid in securing an acetabular cup within an acetabulum. The anchor may be implanted within an ischial defect of the pelvis, and is attached to an outer surface of the acetabular cup shell. The anchor is made at least in part of, and may be made entirely of, a porous metal material to facilitate the ingrowth of surrounding bone into the anchor for osseointegrating the anchor into the surrounding bone. The anchor may be secured to the acetabular shell by a screw fastener or by cement, for example. The anchor may be secured to the acetabular shell before the anchor and the acetabular shell are together implanted into the acetabulum, or the anchor may be implanted into the ischial defect, followed by seating the acetabular shell in the acetabulum and then securing the acetabular shell to the anchor.

A method of locating an acetabular cup implant (100) in a pelvis comprises locating a plurality of reference points on the pelvis, defining a target location of the implant relative to the reference points, and placing the implant at the target location. A method of locating a femoral head implant (102) is also disclosed, together with associated guidance systems.

The disclosed medical device comprises an elongated portion adapted to at least partially replace the collum femur wherein said elongated portion is adapted to be at least one of integrated in and connected to a prosthetic spherical portion adapted to replace the caput femur, and wherein said prosthetic spherical portion in tum is adapted to be movably placed in a prosthetic replacement for the acetabulum having at least one extending portion for clasping said prosthetic spherical portion. Further, the elongated portion comprises a restricting portion adapted to restrict the motion range of the spherical portion in relation to said prosthetic replacement for the acetabulum, and wherein said restricting portion of said elongated portion comprises at least one recess adapted to receive a portion of said prosthetic artificial acetabulum, when implanted, to enable an advantageous motion range in relation to said prosthetic replacement for the acetabulum.