Abstract: A prosthesis (13) is provided which includes at least two intersecting cone-like bodies (18,20) whose outer surfaces engage the end of a patient's bone (28). Cavities (180,200) for receiving the cone-like bodies (18,20) can be readily formed in the patient's bone with a high level of precision. Through the use of the two cone-like bodies, the prosthesis can have neutral version and yet be used at various version angles without sacrificing the integrity of the patient's bone or the degree of securement of the prosthesis.

Abstract: A prosthesis (13) is provided which includes at least two intersecting cone-like bodies (18,20) whose outer surfaces engage the end of a patient's bone (28). Cavities (180,200) for receiving the cone-like bodies (18,20) can be readily formed in the patient's bone with a high level of precision. Through the use of the two cone-like bodies, the prosthesis can have neutral version and yet be used at various version angles without sacrificing the integrity of the patient's bone or the degree of securement of the prosthesis.

Abstract: A ball and socket joint for implanting in the body is provided wherein the sooket portion of the joint can have various orientations with respect to the patient's anatomy, and the orientation used for a particular patient can be selected and/or changed in situ, that is, during or after implantation of the joint. In addition, the configuration of the joint, e.g., constrained versus semi-constrained, as well as the materials making up the socket portion of the joint, e.g., plastic versus metal, can be selected and/or changed in situ.

Abstract: A plug is provided for securing two components of an orthopedic implant where at least one of the components is formed of material softer than the material of the plug. In a preferred embodiment the components comprise concentric cups rotatable with respect to one another about an axis. The components are fixable using a plug to prevent rotation of the components with respect to each other. The invention is preferably used with an acetabular shell and liner of a hip implant wherein the shell is comprised of metal material and the liner is comprised of a polymer or other similar soft material. The plug has a serrated head and a distal lip or anchoring edge to provide securement at more than one location along the length of the plug. The plug is insertable into a common opening defined by aligned recesses or openings of the two components of the implant.

Abstract: Instrumentation is provided for forming a cavity in the distal femur and for using that cavity as a reference for making exterior distal cuts of the femoral bone. At least a part of the walls of the cavity are formed by the cortical (hard) bone of the femur. In addition to its use in cutting the exterior bone, the cavity also serves to affix a femoral knee prosthesis to the femoral bone.

Abstract: Instrumentation is provided for forming a cavity in the distal femur and for using that cavity as a reference for making exterior distal cuts of the femoral bone. At least a part of the walls of the cavity are formed by the cortical (hard) bone of the femur. In addition to its use in cutting the exterior bone, the cavity also serves to affix a femoral knee prosthesis to the femoral bone.

Abstract: A prosthetic joint system is provided for use when replacement of bone is required. The system includes an elongated stem having a joint motion surface at one end and an outside surface which includes at least one tapered portion, a sleeve for fixation to the patient's bone which has an internal taper for locking engagement with the at least one tapered portion, and a bone replacement element which can be a bone graft. The system includes means for attaching the bone replacement element to the stem at a location between the joint motion surface and the sleeve. In the case of bone grafts, the system can include a second sleeve for implantation in the graft and a second tapered portion on the stem for locking engagement with the second sleeve. Preferably, a series of mating stems, sleeves, and bone replacement elements, or second sleeves in the case of bone grafts, are provided.

Abstract: An acetabular cup for use with a plastic socket bearing is provided. The cup includes a circular aperture having a stepped configuration. A domed disc is inserted in the aperture and deformed to seal the aperture. In this way, plastic particles, which are generated by wear of the bearing during use, are prevented from migrating through the aperture to the bone surrounding and supporting the prosthesis.

Abstract: A surgical instrument 20 for machining a precise cavity in a patient's bone for receiving a prosthesis 13 having a conical portion 6 and a triangular portion 8 is provided. The instrument 20 includes a first member 26 which has (i) a conical portion 44 which defines a longitudinal axis 40 and (ii) a guide path 46, 76 for receiving a movable second member 24. The movable second member 24 carries a triangle cutter 22. The movable second member 24 is moved along the longitudinal axis 40 to cut bone until an appropriate index 30 on the movable second member 24 is aligned with a reference surface 28 on the first member 26. This alignment indicates that the triangular cavity formed by cutter 22 is of the appropriate size for the triangular portion 8 of the prosthesis 13 which is to be implanted.

Abstract: A prosthesis (13) for implantation in a patient's bone (2) is provided which has a metal fixation member (10), a metal orienting member (20) secured to the fixation member (10) by a self-locking taper (15,24), and a plastic bearing (30) which is secured to the orienting member (20) in a predetermined orientation. By means of this structure, the plastic bearing (30) can be given a desired orientation with regard to the metal fixation member (10) independent of the orientation of the fixation member (10) with respect to the patient's bone (2). Also, replacement and/or reorientation of the bearing (30) are facility. The prosthesis (13) can be used to form the tibial component of an artificial knee joint.

Abstract: An acetabular prosthesis (8) having an orientable socket bearing (13) and a cup (10) for fixation to bone (6) is provided. The bearing (13) has a male taper (26) which locks into a corresponding female taper (28) formed in the cup (10) . Two screws (15) are used to seat the bearing (13) in the cup (10) and to further secure the taper lock. The assembly of the bearing (13) and cup (10) forms a set of peripheral apertures (4) through which bone screws (15) can pass to further secure the cup (10) to the patient's bone (6).

Abstract: A sintered coating (13) for an implantable prosthesis (10) is provided having 1) interstices into which tissue or bone can grow, and 2) increased surface roughness which provides enhanced initial press-fit fixation. In certain embodiments, the coating includes at least two sets of particles (46,48) having different mean diameters. The sizes and numbers of particles are chosen so as to produce a matrix of smaller particles (48) in which are embedded a lesser number of spaced-apart larger particles (46). The smaller particles (48) provide support for the larger particles (46), and the larger particles (46) stand proud of the smaller particles (48) to provide the enhanced surface roughness. In other embodiments, the coating includes both generally smaller spherically-shaped (SS) particles and generally larger non-spherically-shaped (NSS) particles, with the NSS particles providing enhanced surface roughness and the SS particles providing support for the NSS particles.

Abstract: An oblong acetabular cup which includes a cavity for receiving a bearing element is provided. The plane of the opening into the cavity is skewed relative to the prosthesis' longitudinal plane so as to achieve adduction correction, anteversion correction, or both adduction and anteversion correction. In certain preferred embodiments, the prosthesis is constructed from two components which can be oriented with respect to one another to achieve different directions and amounts of anteversion correction. In some embodiments, the two components form a cusp in the outside surface of the prosthesis. Surgical instruments and surgical methods for implanting the prostheses are disclosed.

Abstract: A sinterable coating for an implantable prosthesis is provided having 1) interstices into which tissue or bone can grow, and 2) increased surface roughness which provides enhanced initial press-fit fixation. The coating includes at least two sets of particles having different mean diameters. The sizes and numbers of particles are chosen so as to produce a matrix of smaller particles in which are embedded a lesser number of spaced-apart larger particles. The smaller particles provide support for the larger particles, and the larger particles stand proud of the smaller particles to provide the enhanced surface roughness.

Abstract: An oblong acetabular cup which includes a cavity for receiving a bearing element is provided. The plane of the opening into the cavity is skewed relative to the prosthesis' longitudinal plane so as to achieve adduction correction, anteversion correction, or both adduction and anteversion correction. In certain preferred embodiments, the prosthesis is constructed from two components which can be oriented with respect to one another to achieve different directions and amounts of anteversion correction. In some embodiments, the two components form a cusp in the outside surface of the prosthesis. Surgical instruments and surgical methods for implanting the prostheses are disclosed.

Abstract: An acetabular prosthesis (8) having an orientable metal socket bearing (13) and a cup (10) for fixation to bone (6) is provided. The bearing (13) has a male taper (26) which locks into a corresponding female taper (28) formed in the cup (10). Two screws (15) are used to seat the bearing (13) in the cup (10) and to further secure the taper lock. The assembly of the apertures (4) through which bone screws (15) can pass to further secure the cup (10) to the patient's bone (6).

Abstract: A sinterable coating for an implantable prosthesis is provided having 1) interstices into which tissue or bone can grow, and 2) increased surface roughness which provides enhanced initial press-fit fixation. The coating includes at least two sets of particles having different mean diameters. The sizes and numbers of particles are chosen so as to produce a matrix of smaller particles in which are embedded a lesser number of spaced-apart larger particles. The smaller particles provide support for the larger particles, and the larger particles stand proud of the smaller particles to provide the enhanced surface roughness.

Abstract: An oblong acetabular cup which includes a cavity for receiving a bearing element is provided. The plane of the opening into the cavity is skewed relative to the prosthesis' longitudinal plane so as to achieve adduction correction, anteversion correction, or both adduction and anteversion correction. In certain preferred embodiments, the prosthesis is constructed from two components which can be oriented with respect to one another to achieve different directions and amounts of anteversion correction. In some embodiments, the two components form a cusp in the outside surface of the prosthesis. Surgical instruments and surgical methods for implanting the prostheses are disclosed.

Abstract: A ball and socket joint for implanting in the body is provided wherein the socket portion of the joint can have various orientations with respect to the patient's anatomy, and the orientation used for a particular patient can be selected and/or changed in situ, that is, during or after implantation of the joint. In addition, the configuration of the joint, e.g., constrained versus semi-constrained, as well as the materials making up the socket portion of the joint, e.g., plastic versus metal, can be selected and/or changed in situ. The questions raised in reexamination request Nos. 90/004,732, filed Aug. 26, 1997 and 90/005,596, filed Jun. 22, 1999, have been considered and the results are reflected in this reissue.