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 bone prosthesis is provided which includes an implantable elongate stem member having a bore extending therethrough. The stem member has a proximal end and a distal end with at least one slot formed in the distal end. The slot extends along at least a portion of the stem member, in a longitudinal direction, from the distal end towards the proximal end to form at least two tines at the distal end of the stem. A bolt member is disposed within the bore of the stem member and has a proximal end and a distal end, wherein at least a portion of the bolt member proximate the distal end is threaded. An expander nut is disposed between the tines and is threadably matable with the distal end of the bolt member such that rotation of the bolt member in a first direction is effective to draw the expander nut towards the proximal end of the stem member to separate the tines at the distal end of the stem member.

Abstract: An implantable prosthetic component, such as a femoral stem, includes a plurality of bone-engaging ribs which are configured so as to engage dense cancellous bone upon implantation. The ribs have a geometry and spacing for achieving optimal fixation in the medullary canal of the femur by engaging predetermined dense cancellous bone.

Abstract: An alignable orthopedic prosthesis system includes a prosthesis and an alignment guide. The prosthesis includes a stem having at least one keyed component extending along its outer surface. The alignment guide has an alignment body with a guide surface disposed on an inner portion thereof. The guide surface has a key element formed therein for engageably receiving the keyed component of the prosthesis.

Abstract: A bone prosthesis is provided which includes an implantable elongate stem member having a bore extending therethrough. The stem member has a proximal end and a distal end with at least one slot formed in the distal end. The slot extends along at least a portion of the stem member, in a longitudinal direction, from the distal end towards the proximal end to form at least two tines at the distal end of the stem. A bolt member is disposed within the bore of the stem member and has a proximal end and a distal end, wherein at least a portion of the bolt member proximate the distal end is threaded. An expander nut is disposed between the tines and is threadably matable with the distal end of the bolt member such that rotation of the bolt member in a first direction is effective to draw the expander nut towards the proximal end of the stem member to separate the tines at the distal end of the stem member.

Abstract: An orthopaedic prosthesis system for replacement of an articulating portion of a long bone includes a sleeve, a stem, and a neck. The sleeve has an outer bone engagement surface and includes opposed proximal and distal female taper regions. The stem has a distal end for fixation within a long bone and a proximal end including a male taper region engaged with the distal female taper of the sleeve. The neck has a taper post that engages the proximal taper of the sleeve. Both the neck and the sleeve may define axial bores, the axial bore in the sleeve communicating with and being generally coaxial with the two opposed female tapers, and the neck axial bore extending through the taper post. A connecting element can engage the stem, pass through the axial bore in the sleeve, extend into the axial bore in the neck taper post, and engage the neck.

Abstract: The present invention provides an orthopaedic instrument system and method for reaming a long bone to a predetermined depth. The instrument system includes an elongate reamer having a proximal portion and a bone contacting surface with an integral cutting element. A stop indicating sleeve having an axial bore and a stop indicating element is removably disposed about the reamer. The stop indicating sleeve may be provided with a stop element and a distal bone contacting surface. Reaming beyond the predetermined reaming depth forces the stop indicating sleeve proximally and urges the stop element on the sleeve into engagement with a stop engaging element provided on the reamer.

Abstract: A plug for apertures in an acetabular cup is provided. The plug is particularly useful in plugging screw holes. The plug helps to prevent plastic particles from a plastic bearing seated within the cup, from migrating through the aperture into the bone cavity or acetabulum surrounding the acetabular cup.

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: An acetabular cup having an outer surface with a first set of steps formed in a first direction and a second set of steps formed in a different, second direction is effective to provide positional stability and enhanced load transfer after implantation in the acetabulum. The stepped outer surface of the acetabular cup provides a significant increase in effective surface area. The multi-directional first and second steps convert shear loads to compressive loads in their respective directions, resulting in enhanced fixation of the cup.

Abstract: An implantable article includes a textured bone engaging surface having a surface texture pattern formed by a plurality of furrows separated by ridges that are integral with the base material from which the article is formed. The furrows are formed by ablating in the surface a series of intersecting holes. The side walls of the furrows have scalloped edges. The ablating energy can be applied by techniques such as laser ablation and hydrojet ablation.

Abstract: An acetabular cup system is provided in which an insert or liner may be selected from a plurality of types of inserts to be used with an acetabular shell. One insert may be oriented after it is removably inserted into the acetabular shell. After an orientation is selected, it may be permanently fixed by pins. The other insert includes a snap-in ring that allows the insert to be snapped into position with the shell after its orientation is selected. The snap-in insert and ring are removable from the shell using a device for removing such snap-in insert and ring.

Abstract: An implantable article includes a textured bone engaging surface having a surface texture pattern formed by a plurality of furrows separated by ridges that are integral with the base material from which the article is formed. The furrows are formed by ablating in the surface a series of intersecting holes. The side walls of the furrows have scalloped edges. The ablating energy can be applied by techniques such as laser ablation and hydrojet ablation.

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: 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.