Multi-hooded enarthrodial joint implant has a ceramic articulating cup including a ceramic head-receiving cup having an articular surface upon which a head of a joint can articulate, and which, in general, has a margin generally about a hemisphere more or less and at least two hoods that are marginally extended continuations of superior one-half or so of cup containment of a sufficient magnitude to reduce an overall dimension of socket outlet to less than a hemisphere, which can embrace and contain the head. The head is made of ceramic and has a truncated generally circular cross section, a truncated surface with a feature for attachment of the stem, and an opposing articular surface for articulation against the articular surface of the ceramic head-receiving cup. As an ensemble, the cup is combined with the head, typically with a stem, for a total joint implant.

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 the center of the hip joint and a bowl shaped acetabulum as part of the pelvic bone with a concave hip joint surface towards the center of the hip joint. The medical device comprising; an artificial caput femur, comprising a convex surface towards the center of the hip joint. The artificial convex caput femur is adapted to, when implanted: be 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. The medical device further comprises a fixation element comprising a fixation surface adapted to be in contact with the surface of the acetabulum and adapted to fixate the artificial convex caput femur to at least the acetabulum of the pelvic bone.

A medical device for implantation in a hip joint of a patient, the medical device comprising a prosthetic replacement for the acetabulum, wherein the prosthetic replacement for the acetabulum comprises: a first part adapted to be fixated to the femoral bone of the patient; and a second part rotatably connected to the first part by means of a connecting member. The first part comprises a bowl-shaped inner contacting surface portion adapted to receive a bowl-shaped outer contacting surface portion of the second part such that the second part is rotatable, relative to the first part, around a point of rotation formed by the connecting member. The second part comprises a bowl-shaped inner surface adapted to receive a ball-shaped portion of a prosthetic replacement for the caput femur, adapted to be fixated to the pelvic bone, such that the prosthetic replacement for the caput femur and the second part form a ball joint in an opposite configuration. The inner contacting surface of the second part comprises an equator line being the largest circumference of the inner contacting surface, and at least one extending portion extending beyond the equator line and being adapted to clasp the ball-shaped portion of the prosthetic replacement for the caput femur.

A medical device for treating hip joint osteoarthritis in a human patient by providing at least one artificial hip joint surface is provided. The hip joint having a ball shaped caput femur as the proximal part of the femoral bone with a convex hip joint surface towards the centre of the hip joint and a bowl shaped etabulum as part of the pelvic bone with a concave hip joint surface towards the centre of the hip joint. The medical device comprises the artificial hip joint surface comprising at least one of; an artificial caput femur or an artificial caput femur surface comprising, a convex form towards the centre of the hip joint, and an artificial acetabulum or an artificial acetabulum surface comprising, a concave form towards the centre of the hip joint. The artificial convex caput femur or the artificial convex caput femur surface is adapted to be fixated to the pelvic bone of the human patient and the artificial concave acetabulum or artificial concave acetabulum surface is adapted to be fixated to the femoral bone of the human patient.

A medical device for delivering an action to an area of a hip joint or its surroundings, inside a human body, is provided. The hip joint of a patient comprises a collum femur and a ball shaped caput femur, being the proximal parts of the femoral bone, and an acetabulum, being a bowl shaped part of the pelvic bone. The medical device comprising; an elongated member, having a length axis along its elongated distribution, comprising a first portion, adapted to enter the body of the patient, and a mechanical element, adapted to be used during an operation in the hip joint or its surroundings, inside the body. The first portion of the elongated member comprises a holding member adapted to hold the mechanical element inside the body of the patient, wherein the first portion of the elongated member have a first portion cross-section area substantially perpendicular to the length axis of the elongated member. The first portion is adapted to pass through a hole, in a bone of the patient, the hole having a hole cross-section area. The first portion cross-section area, is adapted to be smaller than said hole cross-section area. The mechanical element have a functional status, ready to deliver said action inside said body, when held by the holding member inside the body of the patient. The mechanical element is adapted to have a mechanical element cross-sectional area substantially perpendicular to the length axis of the elongated member, substantially larger than the first portion cross-sectional area and adapted to be unable to pass through the hole, when the mechanical element is in the functional status.

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.

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 reduces wear in total joint articulations by modifications of the shape of either component of the kinematic pair, so as to result in an annular surface contact between the two components. Fluid trapped between the two components within the inner contour of the annular contact area is pressurized under load due to elastic deformation of the components and exuded out through inter-articular gap over the surface of contact, aiding in lubrication and reducing the wear. Reduced to practice for a total hip joint with UHMWPE-metal pair, the wear rate tested in a hip joint simulator up to five million cycles was reduced by factor seven to fifteen compared to conventionally shaped components.

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.

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.