Product and methods for interlocking reverse hip and revision prosthesis

A hip prosthesis kit comprising

• a unitary acetabular cup having a non-articulating surface for attachment to an acetabular socket in a pelvic bone and a concave surface located opposite to the non-articulating surface, the concave surface having an acetabular cup stem firmly affixed therein and projecting outwardly therefrom,
• an acetabular ball firmly affixed to the acetabular cup stem, the acetabular ball having a surface,
• the concave surface of the acetabular cup and the surface of the acetabular ball are spaced from one another, thereby defining a gap therebetween,
• a femoral implant for implantation in a medullary canal of a proximal end of a femur, the femoral implant having a femoral implant stem extending proximally therefrom,
• a femoral cup firmly affixed to a proximal end of the femoral implant the femoral cup having a femoral cup recess sized to receive the femoral implant stem, the femoral cup recess being disposed in a neck projecting outwardly from the femoral cup in a direction opposite a concave surface thereof, the neck having a length,
• the femoral cup being sized for articulation in the gap, such that the femoral cup concave surface is sized for articulation on the surface of the acetabular ball and a convex surface opposite the concave surface of the femoral cup sized for articulation on the concave surface of the acetabular cup, the gap being sized and configured to permit said articulation while constraining the femoral cup within the gap throughout an entire range of said articulation of the femoral cup as it articulates within the gap, thereby reducing the risk of dislocation, and
• one or more additional femoral cups having different neck lengths.

A method of implanting in a patient a hip prosthesis having increased stability at extreme ranges of motion comprising:

• providing the hip prosthesis, the hip prosthesis comprising:
• a unitary acetabular cup having a non-articulating surface for attachment to an acetabular socket in a pelvic bone and a concave surface located opposite to the non-articulating surface, the concave surface having an acetabular cup stem firmly affixed therein and projecting outwardly therefrom,
• an acetabular ball firmly affixed to the acetabular cup stem, the acetabular ball having a surface,
• the concave surface of the acetabular cup and the surface of the acetabular ball are spaced from one another, thereby defining a gap therebetween,
• a femoral implant for implantation in a medullary canal of a proximal end of a femur,
• a femoral cup firmly affixed to a proximal end of the femoral implant, the femoral cup having a femoral cup stem projecting outwardly therefrom in a direction opposite a concave surface thereof, the femoral cup stem having a length, and the femoral implant having at its proximal end a recess sized to receive the femoral cup stem,
• the femoral cup sized for articulation in the gap, such that the femoral cup concave surface is sized for articulation on the surface of the acetabular ball and a convex surface opposite the concave surface of the femoral cup sized for articulation on the concave surface of the acetabular cup, the gap being sized and configured to permit said articulation while constraining the femoral cup within the gap throughout an entire range of said articulation of the femoral cup as it articulates within the gap, thereby reducing the risk of dislocation, and
• one or more additional femoral cups having different stem lengths, comprising
• preparing an acetabular socket in a pelvis and firmly affixing the acetabular cup therein, preparing a medullary canal at the proximal end of a femur and affixing the femoral implant therein, affixing the acetabular ball to the acetabular cup stem, selecting the femoral cup having an appropriate stem length for the patient, affixing the femoral cup to the proximal end of the femoral implant and aligning the concave surface of the femoral cup with the acetabular ball so that the concave surface of the femoral cup will articulate on the acetabular ball.

A revision surgery method of implanting in a patient a hip prosthesis having increased stability at extreme ranges of motion comprising:

• providing the hip prosthesis, the hip prosthesis comprising:
• a unitary first acetabular cup having a non-articulating surface for attachment to an acetabular socket in a pelvic bone and a concave surface located opposite to the non-articulating surface, the concave surface having an acetabular cup stem firmly affixed therein and projecting outwardly therefrom,
• an acetabular ball firmly affixed to the acetabular cup stem, the acetabular ball having a surface,
• the concave surface of the first acetabular cup and the surface of the acetabular ball are spaced from one another, thereby defining a gap therebetween,
• a femoral implant for implantation in a medullary canal of a proximal end of a femur, and
• a femoral cup firmly affixed to a proximal end of the femoral implant, the femoral cup having a femoral cup stem projecting outwardly therefrom in a direction opposite a concave surface thereof, the femoral cup stem having a length, and the femoral implant having at its proximal end a recess sized to receive the femoral cup stem,
• the femoral cup sized for articulation in the gap, such that the femoral cup concave surface is sized for articulation on the surface of the acetabular ball and a convex surface opposite the concave surface of the femoral cup sized for articulation on the concave surface of the acetabuiar cup, the gap being sized and configured to permit said articulation while constraining the femoral cup within the gap throughout an entire range of said articulation of the femoral cup as it articulates within the gap, thereby reducing the risk of dislocation, and
• one or more additional femoral cups having different stem lengths, wherein
• the patient having an implant in need of revision, the implant comprising a second hip joint prosthesis with an implanted second acetabular cup and a second femoral stem having an articulating femoral ball affixed to a proximal end thereof, the implanted second acetabular cup having a concave articulating surface, the method further comprising
• removing the second femoral stem and articulating femoral ball,
• firmly affixing to the concave articular surface of the implanted second acetabular cup the first acetabular cup,
• preparing a medullary canal at the proximal end of the femur and affixing the femoral implant therein, affixing the acetabular hall to the acetabular cup stem, selecting the femoral cup having an appropriate stem length for the patient, affixing the femoral cup to the proximal end of the femoral implant and aligning the concave surface of the femoral cup with the acetabular bail so that the concave surface of the femoral cup will articulate on the acetabular ball.