A system and method for further improving upon an ability of a surgeon to reduce or eliminate impaction forces when installing or assembling a prosthesis. An implant includes a surface treatment and/or foundational structural regions for aiding operations with the implant. For example, some surface treatments and foundational structural regions provide an asymmetry in installation versus removal to bias the associated implant deeper into an installation site.

The invention relates to a device for producing a spacer having a stem mold (1) which has an inner space (2), wherein the inner space (2) is accessible via a proximal opening (3) and wherein the stem mold (1) has a proximal wall (4) which peripherally delimits the proximal opening (3) of the stem mold (1), a head mold (5) which has in the interior thereof a hollow space (6), wherein the hollow space (6) has a spherical surface-shaped inner surface (7) and is accessible via a distal opening (8), wherein the head mold (5) has a distal wall (9) which peripherally delimits the distal opening (8) of the head mold (5), a metal core (10) which has a stem part (12), a head part (14) and a flange (16), wherein the flange (16) projects out from the metal core (10), is arranged between the stem part (12) and the head part (14) and has a proximal surface (18) and a distal surface (20), wherein the stem mold (1) and the stem part (12) are shaped such that the stem part (12) is arranged in the inner space (2), when the proximal wall (4) is resting against the distal surface (20), and wherein the head mold (5) and the head part (14) are shaped such that the head part (14) is arranged in the hollow space (6), when the distal wall (9) is resting against the proximal surface (18).

The invention also relates to a set with such a device and to a method for producing spacers with such a device.

Arthroplasty components include an articular surface and a bone-facing surface. The bone-facing surface bears at least one anchoring element adapted for an oblique implantation trajectory. The articular surface may include a larger radius of curvature in the superior-inferior direction than in the anterior-posterior direction. An inferior chamfer may be present on the articular surface. Instruments and implantation methods are also disclosed.

A device adapted to be positioned between two bone regions, the device comprising a body having a stabilising arrangement configured such that bone growing from one bone region toward the other engages the stabilising arrangement of the device.

A prosthetic device for a knee joint includes a body portion and a first keel. The body portion attaches to a bone of a knee joint. The body portion can have a bearing surface configured to replace at least a portion of the bone and an implantation surface configured to face the bone upon implantation. The first keel can be configured to be inserted into a corresponding first keel void formed in the bone. The first feel can be configured to project outwardly from the implantation surface by an amount sufficient to inhibit movement of the body portion relative to the bone in both medial and lateral directions upon insertion into the first keel void. The first keel can extend along a longitudinal direction of the body portion and is offset from a longitudinal centerline of the body portion. Methods of implanting and removing the prosthetic device are also provided.

Some embodiments of the invention provide an apparatus that (1) delivers a fusion member between two vertebral bodies after at least a portion of the fibrocartilaginous disc between the vertebral bodies has been removed, and (2) affixes the fusion member to the vertebral bodies. In some embodiments, the apparatus includes (1) a fusion member that is delivered and positioned between the vertebral bodies, (2) a delivery mechanism that delivers and positions the fusion member between the vertebral bodies, and (3) an anchoring member that affixes the fusion member to the vertebral bodies.

A ceramic femoral resurfacing head prosthesis (110) comprises a ceramic convex outer contact surface (112) engagable with an acetabulum of a patient or an acetabular cup prosthesis and a concave inner fixation surface (114) having an inner-land portion (128), the ceramic convex outer contact surface (112) and the concave inner fixation surface (114) extending to intersect each other at a rim (116). A ceramic stem (120) projects from the concave inner fixation surface (114), and is adapted to be received by a stem bore. The concave inner fixation surface (114) includes a skirt (134) which is cylindrical or substantially cylindrical, or frusto-conical or substantially frusto-conical, and at least one circumferentially elongate recess (136) at the skirt (134).

Arthroplasty components include an articular surface and a bone-facing surface. In some examples, the bone-facing surface bears at least one anchoring element adapted for an oblique implantation trajectory. The anchoring element includes a reinforcement plate, a dowel, and surface features. Each surface feature resists forces acting along a different direction. In other examples, the bone-facing surface bears anchoring elements that deform along the primary or longest axis of the anchoring element during insertion. In yet other examples, the bone-facing surface is enlarged relative to the articular surface so that at least a portion of the perimeter of the articular surface is circumscribed by the perimeter of the bone-facing surface.

A device adapted to be positioned between two bone regions, the device comprising a body having a stabilising arrangement configured such that bone growing from one bone region toward the other engages the stabilising arrangement of the device

Hip implant systems described herein can include a distal stem, a proximal body, and a fastener. In some embodiments, the distal stem can include a cavity configured to receive the fastener when a portion of the distal stem is positioned within the proximal body. In some embodiments, the distal stem can include a threaded exterior surface configured to mate with a fastener when a portion of the distal stem is positioned within the proximal body. In some embodiments, a distal end of the distal stem can include an anterior relief configured to conform to interior surface of a femoral canal of a patient.