This invention corresponds to a prosthesis for total or hip resurfacing replacement, which comprises a prosthetic femoral head made of highly cross-linked polyethylene, with a diameter ranging from 38 mm to 64 mm, to articulate with a cup or acetabular component made of metal. When the invention applies to total hip replacement, the polyethylene head includes a metal core, which contains inside the female counterpart (14) to mate with the male counterpart (13) of a Morse taper, located at the upper end of the femoral component. The use of this type of head for total hip replacement, articulated with an ultra-polished acetabular cup, reduces the risk of dislocation, transmits less angular and torque forces to the Morse taper than large metal heads, and avoids the problems related to the metal-metal bearing or with the use of large metal heads with thin polyethylene. When the invention relates to hip resurfacing replacement, the highly cross-linked polyethylene femoral head has a lower polyethylene extension or stem with or without internal metal reinforcement (151) or a metal stem integrated into a metal-back (152). Using these types of heads for hip resurfacing replacement heads eliminates the problems associated with metal-on-metal resurfacing replacements.

The invention describes an implant for wear couples in endoprosthetics, the implant having an outer side, with an outer face, and an inner side, and a hemispherical wear region for accommodating a spherical wear partner being formed on the inner side. The aim of the invention is to reduce the height of the implant as much as possible and to ensure that, e.g., the pelvic bone does not have to be milled down as much. According to the invention, the implant is therefore designed in the form of a ring or annular structure and the outer face permits direct implantation in the body. In order to reduce friction between the spherical wear partner and the implant to a minimum, the implant has a specially designed inner geometry.

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, wherein a contacting portion, of said inner surface is spherical and adapted to face the center of the hip joint when said medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic replacement therefor having a spherical portion, wherein said medical device comprises at least one extending portion, extending said contacting portion of said inner surface such that said at least one extending portion clasps said spherical portion of said caput femur, or a prosthetic replacement therefor, such that said spherical portion is restrained in said medical device. Restraining the caput femur in the medical device reduces the risk that the hip joint dislocates when in use by the patient.

A medical device for implantation in a hip joint and fixated to the pelvic bone of a patient is provided. The medical device has 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 the medical device is implanted. The medical device is adapted to receive a caput femur or a prosthetic caput femur which has a spherical portion. The medical device has at least one extending portion, extending the contacting portion of the inner surface such that the at least one extending portion clasps the spherical portion of the caput femur or a prosthetic caput femur, such that the spherical portion is restrained in the medical device. Restraining the caput femur in the medical device reduces the risk that the hip joint dislocates when in use by the patient.

This invention corresponds to a prosthesis for total or hip resurfacing replacement, which comprises a prosthetic femoral head made of highly cross-linked polyethylene, with a diameter ranging from 38 mm to 64 mm, to articulate with a cup or acetabular component made of metal. When the invention applies to total hip replacement, the polyethylene head includes a metal core, which contains inside the female counterpart (14) to mate with the male counterpart (13) of a Morse taper, located at the upper end of the femoral component. The use of this type of head for total hip replacement, articulated with an ultra-polished acetabular cup, reduces the risk of dislocation, transmits less angular and torque forces to the Morse taper than large metal heads, and avoids the problems related to the metal-metal bearing or with the use of large metal heads with thin polyethylene. When the invention relates to hip resurfacing replacement, the highly cross-linked polyethylene femoral head has a lower polyethylene extension or stem with or without internal metal reinforcement (151) or a metal stem integrated into a metal-back (152). Using these types of heads for hip resurfacing replacement heads eliminates the problems associated with metal-on-metal resurfacing replacements.

An orthopedic prosthesis includes a proximal member which internally accommodates the major motion of a patient, e.g., during walking, thereby reducing wear against a cup or liner. A distal member may be utilized which rotates within a proximal member about an axis aligned with the major motion of the patient. The orthopedic prosthesis may also include a head and neck, the neck being rotatably mounted within the head, the head being rotatably mounted within the acetabulum region of a patient.

A ceramic acetabular cup (10) devoid of a separate liner comprises a part-spherical inner articulating surface (12) for non-captively receiving a femoral head, and an outer surface (14) for enabling direct to bone fixation. An inner radius at or adjacent to a rim (22) of the cup (10) extends to or adjacent to a surface edge of the inner articulating surface (12) to prevent or reduce undesirable effects of impingement of an associated femoral head and/or neck. An inner radius of the inner articulating surface (12) defines an active arc (A) over which an in use femoral head can articulate, and an uppermost portion of the rim (22) defines an offset datum plane (D). An offset (O) between an equatorial centre (E) of the inner articulating surface (12) and the offset datum plane (D) is in a range of around 1 mm towards a pole (24) of the inner articulating surface (12) and around 3.5 mm away from the said pole (24). The active arc (A) extends in a range from around (150) degrees to less than 180 degrees, and a distance between the inner articulating surface, (12) and outer surface (14) on a straight line from the said equatorial centre (E) and passing through the surface edge is equal to or less than 4 mm.

An artificial joint cup, in particular a hip joint cup, for implanting in a cavity in a bone. The joint cup is, in particular, substantially in the form of a spherical dome cup, having a convex outer surface and a concave inner surface. In addition, the joint cup comprises an outer diameter and an inner diameter. The ratio of the difference between the outer diameter and the inner diameter, in relation to the outer diameter, is in a range of between 0.5 and 0.07, preferably between 0.3 and 0.075, particularly preferably between 0.2 and 0.1. The joint cup is manufactured from a ceramic material, and the convex outer surface has a micro-structuring.

A holder for an implantable acetabular cup implant, said holder comprising a body portion and at least one fastening means attached to the body portion which is operable in order to secure said holder to said implantable device.

An orthopedic prosthesis includes a proximal member which internally accommodates the major motion of a patient, e.g., during walking, thereby reducing wear against a cup or liner. A distal member may be utilized which rotates within the distal member about an axis aligned with the major motion of the patient. The orthopedic prosthesis may also include a head and neck, the neck being rotatably mounted within the head, the head being rotatably mounted within the acetabulum region of a patient.