Abstract: A knee prosthesis comprises a femoral component for securement to a femur, the femoral component defining medial and lateral J-shaped condyles and an intercondylar groove; and a fixed bearing tibial component for securement to a tibia, the tibial component having respective bearing surfaces which are fixed with respect to both a tibial engaging component and a stabilising peg for securing the tibial component to a tibia, the respective bearing surfaces being shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion.

Abstract: A multifunctional spacer for knee surgery is described comprising a main body configured for use with a single femoral condyle and having an anterior portion of a first height and a posterior portion of a second height, wherein the second height is greater than, equal to or less than the first height. In addition, the anterior portion and/or the posterior portion is provided with an attachment mechanism for selective attachment of a height adjuster.

Abstract: This invention related to a method of forming a polymer component and comprises blending polymer particles with antioxidant to form a mixture in which the antioxidant coats the polymer particles, irradiating the polymer particles to cross-link the polymer particles therein and forming the irradiated mixture into a consolidated component. The invention also relates to a method of forming an articular surface for a prosthesis and a prosthesis having a polymer articular bearing surface wherein at least one predetermined portion of the bearing surface is provided with cross-linked polymer bonds.

Abstract: A knee prosthesis comprises a femoral component for securement to a femur, the femoral component defining medial and lateral J-shaped condyles and an intercondylar groove; and a fixed bearing tibial component for securement to a tibia, the tibial component having respective bearing surfaces which are fixed with respect to both a tibial engaging component and a stabilising peg for securing the tibial component to a tibia, the respective bearing surfaces being shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion.

Abstract: A multifunctional spacer for knee surgery is described comprising a main body configured for use with a single femoral condyle and having an anterior portion of a first height and a posterior portion of a second height, wherein the second height is greater than, equal to or less than the first height. In addition, the anterior portion and/or the posterior portion is provided with an attachment mechanism for selective attachment of a height adjuster.

Abstract: A femoral stem prosthesis features a proximal section and a distal section, both of which have a medial edge and a lateral edge. The proximal section is generally wider in a medio-lateral direction than the distal section. The proximal section and the distal section both taper inwardly in a medio-lateral direction such that an anterior-posterior thickness of the medial edge is greater than an anterior-posterior thickness of the lateral edge.

Abstract: A femoral head resurfacing implant is described comprising an external articulating surface and an internal fixation surface. A stem projects from the center of the internal fixation surface. The internal fixation surface comprises a top surface, surrounding and substantially orthogonal to a long axis of the stem, a chamfer surface extending downwardly and outwardly from the top surface and a side surface extending substantially parallel to the long axis of the stem. At least one projection is arranged on the internal fixation surface to provide a predetermined gap between the top surface and/or chamfer surface and a resected head onto which the implant is to be fitted. Furthermore, the side surface constitutes or comprises a cement containment feature configured to restrict or eliminate outflow of cement from the predetermined gap.

Abstract: This invention relates to a method of forming a polymer component and comprises blending polymer particles with antioxidant to form a mixture in which the antioxidant coats the polymer particles, irradiating the polymer particles to cross-link the polymer particles therein and forming the irradiated mixture into a consolidated component. The invention also relates to a method of forming an articular surface for a prosthesis and a prosthesis having a polymer articular bearing surface wherein at least one pre-determined portion of the bearing surface is provided with cross-linked polymer bonds.

Abstract: The invention relates to a prosthesis comprising a first component (10) and a second component (60), wherein the first and second components have respective inter-engaging parts (24,64) and wherein at least one of the first or second components comprises an anti-rotational element (32,66) configured to resist rotational movement between the inter-engaging parts and wherein the inter-engaging parts share an axis of rotation such that they are engageable in a plurality of relatively rotated positions and wherein the axis of rotation of the inter-engaging part of one of the first or second components is parallel to but offset from a central axis of said first or second component.

Abstract: A prosthesis comprises a femoral stem having a frustoconical femoral neck; a femoral head having an articular bearing surface with an outer diameter of 26 mm or more, and a frustoconically tapered internal recess; and a sleeve comprising a frustoconical body for insertion into the recess of the femoral head and a frustoconically tapered internal recess for receipt of the frustoconical femoral neck. A surface of the recess of the sleeve comprises oxidized zirconium or oxidized zirconium alloy to resist or minimize mechanically assisted crevice corrosion.

Abstract: An acetabular cup prosthesis features conical pegs. The edge of each peg has an outer portion facing away from the edge of the other peg, and the outer portions of the pegs are parallel to or converging toward each other such that, when in use, the prosthesis can be securely inserted into a prepared bone cavity.

Abstract: This invention related to a method of forming a polymer component and comprises blending polymer particles with antioxidant to form a mixture in which the antioxidant coats the polymer particles, irradiating the polymer particles to cross-link the polymer particles therein and forming the irradiated mixture into a consolidated component. The invention also relates to a method of forming an articular surface for a prosthesis and a prosthesis having a polymer articular bearing surface wherein at least one predetermined portion of the bearing surface is provided with cross-linked polymer bonds.

Abstract: A femoral stem prosthesis features a proximal section and a distal section, both of which have a medial edge and a lateral edge. The proximal section is generally wider in a medio-lateral direction than the distal section. The proximal section and the distal section both taper inwardly in a medio-lateral direction such that an anterior-posterior thickness of the medial edge is greater than an anterior-posterior thickness of the lateral edge.

Abstract: A prosthesis comprises a femoral stem having a frustoconical femoral neck; a femoral head having an articular bearing surface with an outer diameter of 26 mm or more, and a frustoconically tapered internal recess; and a sleeve comprising a frustoconical body for insertion into the recess of the femoral head and a frustoconically tapered internal recess for receipt of the frustoconical femoral neck. A surface of the recess of the sleeve comprises oxidised zirconium or oxidised zirconium alloy to resist or minimise mechanically assisted crevice corrosion.

Abstract: A femoral head resurfacing implant is described comprising an external articulating surface and an internal fixation surface. A stem projects from the center of the internal fixation surface. The internal fixation surface comprises a top surface, surrounding and substantially orthogonal to a long axis of the stem, a chamfer surface extending downwardly and outwardly from the top surface and a side surface extending substantially parallel to the long axis of the stem. At least one projection is arranged on the internal fixation surface to provide a predetermined gap between the top surface and/or chamfer surface and a resected head onto which the implant is to be fitted. Furthermore, the side surface constitutes or comprises a cement containment feature configured to restrict or eliminate outflow of cement from the predetermined gap.

Abstract: This invention related to a method of forming a polymer component and comprises blending polymer particles with antioxidant to form a mixture in which the antioxidant coats the polymer particles, irradiating the polymer particles to cross-link the polymer particles therein and forming the irradiated mixture into a consolidated component. The invention also relates to a method of forming an articular surface for a prosthesis and a prosthesis having a polymer articular bearing surface wherein at least one predetermined portion of the bearing surface is provided with cross-linked polymer bonds.

Abstract: An acetabular cup prosthesis comprises at least one recess in an edge of the cup and at least one attachment means. The attachment means has a projecting portion for attachment of the cup to an introducer (configured for insertion of the cup into a patient) and a retaining portion for retaining the attachment means on the cup. The retaining portion is located in a respective one of the recesses and is fixedly secured in the respective recess. A method of manufacture of the cup is also provided.

Abstract: A method of manufacturing a prosthetic component comprises providing crosslinked polymer in a mould and moulding non-crosslinked polymer to a free edge of the crosslinked polymer to form a hybrid component. A portion of the crosslinked polymer and a portion of the non-crosslinked polymer is then removed so as to form a prosthetic component having a full thickness crosslinked wear zone and at least one non-crosslinked edge.

Abstract: A femoral head prosthesis (110) comprises an articulating surface (112) which is more than hemi-spherical; an internal recess (114) having a longitudinal axis defining a pole P of the articulating surface (112), the longitudinal axis passing through the center of curvature of the articulating surface (112); a first edge (116) which constitutes a posterior edge in use, and a second edge (118) which constitutes an anterior edge and/or an antero-inferior edge in use. The first edge (116) is further from the pole P than the second edge (118). Also provided is a femoral prosthesis comprising a femoral head, and a femoral implant comprising a femoral stem and a femoral head. The prostheses and implants of the invention find use in total hip replacements.

Abstract: A knee prosthesis comprises a femoral component for securement to a femur, the femoral component defining medial and lateral condyles and an intercondylar groove; and a tibial component for securement to a tibia, the tibial component having respective bearing surfaces shaped to engage with said condyles both when the knee, in use, is extended and also over a range of flexion. The femoral and tibial components together comprise interengaging means, for stabilising against antero-posterior relative movement of the femoral and tibial components. One of the condyles and the respective bearing surface of the tibial component are at least partially congruent, at least at angles of flexion below a predetermined angle. The other bearing surface is incongruent with the other condyle in at least the antero-posterior direction so as to allow for antero-posterior movement of the femoral component relative to the bearing surfaces of the tibial component.