An artificial disc replacement device is disclosed. The device includes an upper endplate and a lower endplate, as well as a core assembly disposed between the endplates. The core assembly includes a core member with a curved engaging surface and a matrix member. The matrix member is more compressible than the core member. The curved engaging surface of the core member engages a recess in the upper endplate so that the upper endplate can translate along the curved engaging surface. The curved engaging surface has a greater curvature at its posterior end than at its anterior end to facilitate different ranges of motion during extension and flexion.

An intervertebral disc implant for use in the spine including a first part and a second part, wherein the first part and second part are configured as a joint prosthesis for the spine. The first part includes one of a concave or convex articulating surface and the second part includes one of the other concave or convex articulating surface. One of the concave or convex articulating surfaces is preferably elliptically shaped in at least one direction and does not match and is different than one of the other concave or convex articulating surfaces.

A method for fusing spinal bone is provided. The method comprises placing a sac between two or more adjacent sections of the spine to be fused, inserting a cage into the sac, and filling the sac with bone tissue. The surfaces of the sac abutting the sections of the spine comprise porous material for allowing bone to grow between the spine and the sac. Surfaces of the sac not abutting the sections of the spine are nonporous to bodily fluids and thereby prevent premature deterioration of the bone tissue inside the sac. The cage maintains the sac in an expanded state upon filling. A kit comprising the sac and cage is also provided. In other embodiments of the invention, the method comprises placing an inner sac inside the inventive sac and filling the sacs with bone tissue for fusion of spinal bone.

Systems, kits and methods for long bone arthroplasty that include arrays of humeral head prosthesis components, each having on a first side a bone articulation surface that has an overall generally hemielliptical convex shape defined by a major axis and a minor axis, the bone articulation surface having an apex and a base that each has an non-circular elliptical cross sectional shape, the prosthesis components having on an opposite side, adjacent the base, a bone contact surface. The humeral head prosthesis components in the arrays vary from having a base with a more circular cross sectional shape to a more elongated elliptical cross sectional shape with increasing size.

A blade-like stem of a hip joint prosthesis for anchoring in the femur, including a prosthesis neck portion and a femur-anchoring portion extending therefrom and having a proximal end and a distal end, the femur-anchoring portion including a proximal arcuate portion extending from a location adjacent the proximal end and having a radius of curvature that changes in a distal-to-proximal direction, and the femur-anchoring portion further including a distal tapered portion extending from the proximal arcuate portion toward the distal end.

The device for maintaining an intervertebral space is capable of being accommodated inside the disc, in place of the core. Natural anchoring is ensured by promoting the regrowth of fibre around at least part of the device. The possibility of ejection of the residual core is limited in order to avoid a renewed hernia, and mobility of the vertebral column is ensured. To this end, a subject of the invention is a device having at least two non-expansible concentric rings which between them form a free space and which are connected to each other via two junction summits.

A system for long bone arthroplasty includes humeral head prosthesis components, and an array of humeral head prosthesis components, each humeral head prosthesis component in the array having a convex articulation surface that is hemi-elliptical and defined by a major axis, a minor axis, an apex, and a base having an elliptical cross sectional shape defined by a major diameter along the major axis and a minor diameter along the minor axis, wherein the array of elliptical humeral head prosthesis components provides for suitable and sufficient anatomical fit within a variation of up to and not more than 3 mm in at least 96% of a patient population, and up to 99% of a patient population.

A joint prosthesis is provided that includes a proximal implant for attachment to a first portion of skeletal anatomy, the proximal implant including a proximal bone attachment portion and a distal cup portion. The prosthesis also includes a distal implant for attachment to a second portion of skeletal anatomy, the distal implant including a distal bone attachment portion and a proximal cup portion. An inter-joint element is located between the distal cup and the proximal cup. The inter-joint element includes surface portions shaped to complement said cups and is preferably formed as an ovoid. Each of the proximal implant, distal implant and inter-joint element include magnetic regions whereby the inter-joint element is attracted to both the proximal cup portion and to the distal cup portion to thereby provide stability across a large angular motion.

Methods for achieving an anatomically accurate reconstruction with a modular arthroplasty assembly that includes a generally disc shaped coupler component having a prosthesis component side that includes a recess configured to interchangeably engage a prosthesis component selected from a concave cup and a convex head that is either hemispherical or hemielliptical.

The invention relates to a wrist prosthesis (1), comprising a proximal prosthesis body (21) and a distal prosthesis body (11), wherein, at least in a deployed state of the wrist prosthesis, a portion of the proximal prosthesis body that faces away from the distal prosthesis body is provided with a convexly curved surface (22). Additionally, a portion of the distal prosthesis body that faces away from the proximal prosthesis body is furthermore provided with a convexly curved surface (12). Furthermore, the surfaces of the proximal prosthesis body and the distal prosthesis body that are facing each other are provided with complementary convex-concave curved surfaces (13, 23). The invention further relates to a set of components for such a wrist prosthesis, which allows the wrist prosthesis to be placed in a wrist, without anchoring means, and with a high degree of adaptation to the specific situation.