This invention concerns an artificial intervertebral disc for installation in an intervertebral space between adjacent vertebral bodies. The artificial intervertebral disc prosthesis comprises an upper plate, a lower plate and a mobile core element, which is, in use, located between the upper and lower plates. The mobile core element includes a first contoured surface that has a flexion/extension radius that is larger by a determined amount than the radius of its second contoured surface that results in an instantaneous centre of rotation below the midline of the intervertebral disc space, thereby approximating the typical instantaneous centre of rotation of a natural disc. The first contoured surface of the mobile core element has a lateral bending radius that is unequal to the value of the flexion/extension radius, thereby allowing the mobile core element to self-centre on the second surface of the upper plate when under preload. The mobile core element may further be compressible and may include a resilient element located within the mobile core element. Deformation of the resilient element may be contained to obtain an exponential increase in spring stiffness of the resilient element during compression.

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.

A humerus head implant includes a head cap, a fixing component, and a bone-screw component. The head cap has a shape of half-an-ellipsoid extending into a positive z-direction along the z-axis, in positive and negative x-directions, and in positive and negative y-directions. The extension along the x-direction is in a range of 0.8 to 0.95 of the extension in the y-direction. There is a conical recess having a center axis that is displaced in the negative y-direction with respect to the z-axis and configured to interface with a conical section of the fixing component. This allows for rotation of the head cap relative to the fixing component.

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.

One embodiment of the present disclosure relates to a glenoid implant with a body and a keel. The body includes an articulation surface and a bone facing surface, and the keel has a depth that extends from the bone facing surface to a free end of the keel. The keel has a first length and a first width, both measured in a plane perpendicular to a direction of the depth. The first length is measured perpendicular to the first width and is defined by a first distance from an inferior end of the keel to a superior end of the keel. The first width is measured at a first location adjacent to the inferior end, and the keel has a width dimension along a first portion of the keel from the first location to the superior end that tapers from the first location toward the superior end.

A shoulder implant system comprising a glenoid implant; a baseplate comprising an implant facing surface to face the glenoid implant; wherein the glenoid implant comprises at least one fixation element configured to engage with at least one fixation element of the baseplate; wherein the at least one fixation element of the glenoid implant comprises a center post having a distal end; wherein the at least one fixation element of the baseplate comprises a center post receptacle; wherein the baseplate comprises an outer periphery; wherein the implant facing surface of the baseplate comprises a channel which extends from the outer periphery of the baseplate to the center post receptacle of the baseplate; and wherein the channel is configured such that, during an assembly of the glenoid implant and the baseplate, the distal end of the post is movable in the channel from the outer periphery of the baseplate to the center post receptacle of the baseplate.

An intervertebral implant can include a housing having a first end and second end with a top side and bottom side therebetween, with at least one engagement opening in the top side and/or bottom side, the implant having a first dimension from the top side to the bottom side; a shaft rotatably located within the housing and having a shaft head exposed through an end opening in the first end, the shaft head having a tool coupling member; the cam mechanism operably coupled with the shaft such that rotation of the shaft rotates the cam mechanism; and at least one engaging surface operably coupled to the cam mechanism such that rotation of the shaft protrudes and/or retracts each engaging surface through an engagement opening, wherein when each engaging surface protrudes through the engagement opening, the implant has a second dimension that is greater than the first dimension.

This invention relates to an intervertebral motion disc having two motion surfaces and. wherein the radius of the upper articulation surface of the core member is greater than the radius of the lower articulation surface of the core member, and wherein the first articulation surface of the core member is spherical and the second articulation surface of the core member is curved and non-spherical.

A humerus head implant includes a head cap, a fixing component, and a bone-screw component. The head cap has a shape of half-an-ellipsoid extending into a positive z-direction along the z-axis, in positive and negative x-directions, and in positive and negative y-directions. The extension along the x-direction is in a range of 0.8 to 0.95 of the extension in the y-direction. There is a conical recess having a center axis that is displaced in the negative y-direction with respect to the z-axis and configured to interface with a conical section of the fixing component. This allows for rotation of the head cap relative to the fixing component.

This invention relates to an intervertebral motion disc having two motion surfaces and. wherein the radius of the upper articulation surface of the core member is greater than the radius of the lower articulation surface of the core member, and wherein the first articulation surface of the core member is spherical and the second articulation surface of the core member is curved and non-spherical.