Patent Description:
Traditional total shoulder joint replacement involves a humeral implant and glenoid implant. The humeral implant generally includes a metal sphere to replace the head of the humerus and the glenoid implant generally includes a glenoid socket for receiving the sphere attached to a portion of the scapula. However, where the soft tissue has been severely damaged, a reverse shoulder replacement may be used. A reverse shoulder replacement involves reversing the original sphere and glenoid by attaching the glenoid implant to the proximal aspect of the humerus and the convex sphere being attached to the glenoid fossa.

However, currently available replacement prostheses include a sphere and a baseplate that are generally centrally aligned and that utilize locking components to couple the sphere and baseplate together. These are hard to manufacture due to the taper, and can be poorly aligned resulting in limited articulation (e.g., range of motion) of the sphere. Also due to the alignment, disassembly of the sphere component can be challenging, often requiring an extractor claw or like tool which can cause tissue and bone damage that may create complications with the fixation of the baseplate.

<CIT> discloses a joint prosthesis with a base piece for anchoring in the bone, a collar piece articulated thereon and defining a collar axis, and a collar extension on the collar piece situated on the collar axis, an articulation space being formed on the base piece. An articulation head of the collar piece is disposed therein. The joint prosthesis further includes a head cap disposed on the collar extension and at least one pressure piece for pressing the articulation head against the base of the articulation space. The pressure piece and the base piece can be connected.

Therefore, reverse shoulder prostheses that allows for a greater range of articulation, which are easier to manufacture, and which can be more readily disassembled are needed.

Aspects of the present disclosure provide implants and methods for replacing a shoulder joint.

More specifically, the present disclosure provides humeral replacement prostheses and implants that include an offset post and a locking screw.

By offsetting the post and other features, a more versatile prosthesis can be developed allowing for large offsets and differing shoulder sizes to be replaced.

Further, the offset allows for easier access to the locking screw in order to disassemble the prosthesis with an extraction device.

In this way, lower manufacturing costs are achieved on prostheses which are more adaptable and easier to disassemble.

In one aspect, the present invention provides an implant according to the appended set of claims.

These, and other objects, features and advantages of this disclosure will become apparent from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings.

For the purposes of illustrating the humeral prostheses and related methods described herein, there is shown herein illustrative embodiments. These illustrative embodiments are in no way limiting in terms of the precise arrangement and operation of the disclosed humeral replacement prostheses and related methods and other similar embodiments are envisioned within the scope of the present disclosure. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the detailed description herein, serve to explain the principles of the disclosure. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the disclosure. The foregoing and other objects, features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

Generally stated, disclosed herein are implants for replacing an articulation surface in a joint, for example, a shoulder. Further, surgical methods, not in accordance with the appended claims, for replacing an articulation surface in the shoulder using the implants are discussed.

In this detailed description and the following claims, the words proximal, distal, anterior, posterior, medial, lateral, superior, and inferior are defined by their standard usage for indicating a particular part of a bone or implant according to the relative disposition of the natural bone or directional terms of reference. For example, "proximal" means the portion of a device or implant nearest the torso, while "distal" indicates the portion of the device or implant farthest from the torso. As for directional terms, "anterior" is a direction towards the front side of the body, "posterior" means a direction towards the back side of the body, "medial" means towards the midline of the body, "lateral" is a direction towards the sides or away from the midline of the body, "superior" means a direction above and "inferior" means a direction below another object or structure.

Similarly, positions or directions may be used herein with reference to anatomical structures or surfaces. For example, as the current implants, devices, instrumentation and methods are described herein with reference to use with the bones of the shoulder, the bones of the shoulder, upper arm, and torso may be used to describe the surfaces, positions, directions or orientations of the implants, devices, instrumentation and methods. Further, the devices and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to one side of the body for brevity purposes. However, as the human body is relatively symmetrical or mirrored about a line of symmetry (midline), it is hereby expressly contemplated that the devices and methods, and the aspects, components, features and the like thereof, described and/or illustrated herein may be changed, varied, modified, reconfigured or otherwise altered for use or association with another side of the body for a same or similar purpose without departing from the scope of the disclosure. For example, the devices and methods, and the aspects, components, features and the like thereof, described herein with respect to the right shoulder may be mirrored so that they likewise function with the left shoulder. Further, the devices and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to the shoulder for brevity purposes, but it should be understood that the devices and methods may be used with other bones of the body having similar structures, for example the upper extremity, and more specifically, with the bones of the shoulder, upper arm, and torso.

Referring to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference to <FIG>, there are illustrated embodiments of a prosthesis or implant <NUM>, for example, a humeral prosthesis or humeral implant. The terms "humeral implant" and "humeral prosthesis," as used herein, shall not be interpreted as limited to use in the humerus, but may also be used for implanting into the glenoid fossa to be utilized in a reverse shoulder configuration, as well as used in other like joints, as would be known by one of ordinary skill in the art. Methods for implanting and removing the implant <NUM>, not in accordance with the appended claims, as well as a related extraction device are also disclosed. The prosthesis <NUM> includes a baseplate <NUM> (see <FIG>) for connection to a bone, an articulating component <NUM> (see <FIG>) for attaching to the baseplate <NUM>, and a fixation component <NUM> (see <FIG>) for engaging a through hole <NUM> (see <FIG> and <FIG>) in the articulating component <NUM> to couple the baseplate <NUM> and the articulating component <NUM>.

As shown in <FIG>, the baseplate <NUM> includes a projection <NUM> (see <FIG> and <FIG>) extending from a first side <NUM> (see <FIG>, <FIG>, <FIG>, and <FIG>) of the baseplate <NUM>. The projection <NUM> may be, for example, a Morse taper. The projection <NUM> may have a taper, for example, ranging between approximately <NUM>° to <NUM>°, as the projection <NUM> extends away from the baseplate <NUM>. The projection <NUM> is offset from a diametric center <NUM> (see <FIG>) of the baseplate <NUM>. The projection <NUM> may have, for example, a height and a diameter and the height may be larger than the diameter. The baseplate <NUM> includes a post or stem <NUM> (see <FIG>) on a second side <NUM> (see <FIG> and <FIG>). The post <NUM> is also offset relative to the center <NUM> of the baseplate <NUM>, for example, diametrically offset from the projection <NUM>. The post <NUM> extends away from the second side <NUM> of the baseplate <NUM> to an end <NUM> of the post <NUM>. The post <NUM> may be used to attach the baseplate <NUM> to the bone or to stabilize the baseplate <NUM> within a scapula or humerus. The post <NUM> may be of any length or cross sectional geometry necessary to be received within a bone and may be secured within the bone by any means, including but not limited to a surface treatment or structural elements, including ridges, fins, etc..

As shown in <FIG> and <FIG>, the articulating component <NUM> may be, for example, a spherical shaped articulating component <NUM>. The articulating component <NUM> attaches to the baseplate <NUM>, can include, for example, a substantially convex side or articulating surface <NUM>. As illustrated in <FIG>, a cutaway view shows that the articulating component <NUM> includes a corresponding opening or cavity <NUM> for engaging or receiving the projection <NUM> of the baseplate <NUM>. The opening <NUM> may be, for example, a corresponding Morse taper. The opening <NUM> (see <FIG>, <FIG>, and <FIG>) may be offset from a diametric center of the articulating component <NUM>. As illustrated in <FIG>, the articulating component <NUM> may include a recess <NUM> on the opposing side of the convex side <NUM> for accepting a top portion of the baseplate <NUM>. The recess <NUM> may, for example, provide clearance around the baseplate <NUM> for inserting screws (not shown). In addition, the recess <NUM> allows for the base plate <NUM> to be inset into the articulating component <NUM> to position the engagement of the base plate <NUM> and articulating component <NUM> adjacent to the patient's bone. The articulating component <NUM> may also include a lip <NUM> about the diameter of the flat side <NUM> of the articulating component <NUM>. The flat side <NUM> opposes the convex side <NUM>. When assembled, the lip <NUM> will be substantially flush with the second side <NUM> of base plate <NUM> keeping the base plate <NUM> securely nested within the recess <NUM>, as illustrated in <FIG>. The cavity or Morse taper <NUM>, is contained within the recess <NUM>. The convex side <NUM> functions as the articulating surface would in a normal shoulder. The articulating component <NUM> can include a through hole <NUM> (see <FIG>, <FIG>, and <FIG>) extending from a first side, for instance the flat side <NUM>, to a second side, for instance the convex side <NUM>, of the articulating component <NUM>. The through hole <NUM> may be threaded with a set of threads <NUM> as seen in the cutaway of <FIG>, as well as in <FIG>, <FIG>, and <FIG>. In some embodiments, the through hole <NUM> is aligned with the cavity <NUM> as illustrated in <FIG>.

As shown in <FIG>, the fixation component <NUM> may engage or be configured to engage the through hole <NUM> in the articulating component <NUM>. The fixation component <NUM> may also connect the baseplate <NUM> and the articulating component <NUM>. The fixation component <NUM> may include, for example, any screw or like structure. The fixation component <NUM> may be contained within a cavity <NUM> of the baseplate <NUM>. In some embodiments, the cavity <NUM> of the baseplate <NUM> is aligned with and contained partially within the projection <NUM> of the baseplate <NUM>. As illustrated in <FIG>, the fixation component <NUM> may include a widened head <NUM>, which may engage a lip <NUM> within the cavity <NUM>. The widened head <NUM> may prevent the fixation component <NUM> from exiting the first side <NUM> of the baseplate <NUM>. With continued reference to <FIG>, a spring <NUM> may be positioned between the head <NUM> of the fixation component <NUM> and a cap <NUM>. This arrangement creates a biasing force to push the fixation component <NUM> out to engage the articulating component <NUM> when installed. Accordingly, the head <NUM> of the fixation component <NUM> may have a flat surface as illustrated in <FIG> and <FIG>. As noted above, the cap <NUM> may be positioned behind the fixation component <NUM> and the spring <NUM>. The cap <NUM> may engage a threaded portion <NUM> of the cavity <NUM> to capture the spring <NUM> and the fixation component <NUM>, which when assembled may fit flush on the second side <NUM> of the baseplate <NUM>, as illustrated in <FIG>. In some embodiments, the cap <NUM>, spring <NUM>, and fixation component <NUM> may be preassembled before purchase of the prosthesis <NUM>, limiting the number of parts needing to be assembled in the operating room.

As illustrated in <FIG>, the circumference <NUM> of cap <NUM> may be threaded in order to engage the threaded portion <NUM> of baseplate <NUM>. As shown in <FIG>, the internal surface <NUM> of cap <NUM> may be flat where the cap <NUM> will contact the spring <NUM>. As shown in <FIG>, <FIG>, <FIG>, and <FIG>, the external surface <NUM> of cap <NUM> may include an engagement surface <NUM>, which may have, for example, any surface, shape, or feature for coupling or securing the cap <NUM> to the threaded portion <NUM> of baseplate <NUM>.

Also disclosed is an extraction device <NUM>, illustrated in <FIG>, for use with a prosthesis <NUM> according to any of the embodiments above. The extraction device <NUM> may include a handle <NUM>, for example, a circular end. The handle <NUM> may be, for example, a handle for rotating the extraction device <NUM> or alternatively, a coupling component for engaging a rotating device, such as a drill. Extending from the handle <NUM> may be a threaded portion <NUM>, for engaging a set of threads <NUM> in the articulating component <NUM> of the prosthesis <NUM>. Thus, the threaded portion <NUM> can be inserted into the through hole <NUM> of the articulating component <NUM> by engaging the threads <NUM> from the convex side <NUM>, opposite the direction of the fixation component <NUM>. Referring now to <FIG>, the tip <NUM> of the extraction device <NUM> may have an engagement projection <NUM>. As seen in <FIG>, the tip of the fixation component <NUM> may have an engagement recess <NUM>. The engagement projection <NUM> may have a cross-sectional shape of, for example, hexagonal, square, or the like to engage the engagement recess <NUM> of the fixation component to effectively push the fixation component <NUM> out of the flat side <NUM> of the articulating component <NUM> against the force of the spring <NUM> as the extraction device <NUM> is rotated. This will allow for the uncoupling of the articulating component <NUM> from the baseplate <NUM> via the extraction device <NUM> without any force being applied against the bone implant interface.

Also disclosed is a method of using a prosthesis <NUM>, not in accordance with the appended claims. For instance, baseplates according to the embodiments above may be positioned within a scapula. Although described as a reverse shoulder replacement, it should be understood that the baseplate can be positioned in the proximal humerus as well, providing an articulating convex surface in its correct anatomic placement. Next, an articulating component as in the above embodiments can be attached to the baseplate, using a hole extending from a first side of the articulating component to a second side of the articulating component, and threaded to receive a fixation component contained within the baseplate.

Referring now to <FIG>, another implant or prosthesis <NUM> is shown. The implant <NUM> may be, for example, a humeral prosthesis or humeral implant. The terms "humeral implant" and "humeral prosthesis," as used herein, shall not be interpreted as limited to use in the humerus, but may also be used for implanting into the glenoid fossa to be utilized in a reverse shoulder configuration, as well as used in other like joints, as would be known by one of ordinary skill in the art. The implant <NUM> includes an articulating member or component <NUM>, a base member or portion <NUM>, and a coupling portion <NUM> for connecting the articulating member <NUM> to the base member <NUM>.

As shown in <FIG>, the articulating member <NUM> may include an articulating surface <NUM> and an interior surface <NUM>. The articulating surface or exterior surface <NUM> may, for example, have a convex or half spherical shape. The interior surface, flat side, or engagement portion <NUM> may include an outer lip or lip <NUM> surrounding the exterior portion of the interior surface <NUM>. The outer lip <NUM> may include, for example, a width and the width may vary around the circumference of the lip <NUM>. The interior surface <NUM> may also include a recess <NUM> positioned within the lip <NUM> and sized and shaped or configured to receive a portion of the base member <NUM>, as shown in <FIG> and <FIG>. The interior surface <NUM> may further include a cavity <NUM> extending into the articulating member <NUM> from the recess <NUM> toward the articulating surface <NUM>, as shown in <FIG>, <FIG> and <FIG>. The cavity <NUM> may extend, for example, through only a portion of the articulating member <NUM> or, alternatively, from the recess <NUM> entirely through the articulating surface <NUM> forming a through hole. The cavity <NUM> may be, for example, positioned at a center of the articulating member <NUM>, as shown. Alternatively, it is contemplated that the cavity <NUM> may be positioned, for example, offset from the center, such as, being shifted anteriorly, to allow for building an offset away from the scapula.

With continued reference to <FIG>, the articulating member <NUM> may also include a threaded portion or threads <NUM>. The threaded portion or threads <NUM> may, for example, extend along at least a portion of the interior surface of the cavity <NUM> or, alternatively, the threaded portion or threads <NUM> may be positioned adjacent to the cavity <NUM>. For example, as shown in <FIG>, the threaded portion <NUM> extends from a bottom of the cavity <NUM> through the articulating member <NUM> to the articulating surface <NUM>. The threaded portion <NUM> may have, for example, a diameter smaller than the diameter of the cavity <NUM>. The cavity <NUM> and threaded portion <NUM> may together form a through hole extending from the interior surface <NUM> through the articulating member <NUM> to the articulating surface <NUM>, as shown in <FIG>. The cavity <NUM> may be, for example, tapered as it extends from the interior surface <NUM> of the articulating member <NUM> toward the articulating surface <NUM>. The cavity <NUM> may have, for example, a height and a first width or diameter at a first end and the height may be larger than the first width.

The base member or base portion <NUM> is shown in <FIG>. The base member <NUM> includes a plate portion <NUM> with a top surface <NUM> and a bottom surface <NUM>. The plate portion <NUM> may also include a plurality of openings or through holes <NUM> extending through the plate portion <NUM> from a top surface <NUM> to the bottom surface <NUM>, as shown in <FIG>. The base member <NUM> also includes a projection <NUM> extending away from the top surface <NUM> of the plate portion <NUM>, as shown in <FIG>. The projection <NUM> may be positioned, for example, generally centered on the top surface <NUM> of the plate portion <NUM> with the plurality of openings <NUM> positioned around the exterior surface of the projection <NUM>, as shown in <FIG>. The projection <NUM> may be, for example, tapered as it extends away from the top surface <NUM> of the base member <NUM>. The projection <NUM> may have a taper, for example, ranging between approximately <NUM>° to <NUM>°, as the projection <NUM> extends away from the base member <NUM>. The projection <NUM> may have, for example, a height and a first width or diameter positioned where the projection <NUM> couples to the plate portion <NUM> and the height may be larger than the first diameter. The projection <NUM> may also include a cavity or opening <NUM> extending into the projection <NUM> from a first or top end, as shown in <FIG> and <FIG>. With continued reference to <FIG> and <FIG>, the cavity <NUM> may further include a recess or spring opening <NUM> in a bottom surface of the cavity <NUM>. The recess <NUM> may, for example, extend into the top surface <NUM> of the plate portion <NUM>, as shown in <FIG>. The cavity <NUM> may also include threads <NUM>, for example, along at least a portion of the interior wall of the cavity <NUM>. The threads <NUM> may extend, for example, between a top of the projection <NUM> down to a bottom surface of the cavity <NUM> or along any portion of the interior surface of the cavity <NUM> between the top of the projection <NUM> to the bottom surface, as shown in <FIG> and <FIG>.

The base member <NUM> further includes a stem <NUM>, as shown in <FIG>. The stem <NUM> extends away from the bottom surface <NUM> of the plate portion <NUM>. The stem <NUM> is offset from the center of the bottom surface <NUM> of the plate portion <NUM>, as shown in <FIG> and <FIG>. Further, the stem <NUM> may be offset from the projection <NUM> in at least one direction from the diametric center, as shown in <FIG>, <FIG>, <FIG>, and <FIG>. The stem <NUM> may also, be positioned between two openings <NUM>, as shown in <FIG> and <FIG>. The stem <NUM> may further include an opening <NUM> extending from the distal end into the stem <NUM>, as shown in <FIG>, <FIG>, and <FIG>. As shown in <FIG>, the opening <NUM> may be, for example, tapered as the opening <NUM> extends toward the plate portion <NUM>.

Referring now to <FIG>, <FIG>, and <FIG>, the coupling portion <NUM> is shown. The coupling portion <NUM> includes a spring or elastic member <NUM>, a first fixation component or articulating coupler <NUM>, and a second fixation component or base coupler <NUM>. A first end of the first fixation component <NUM> receives at least a portion of the spring <NUM> and a second end of the first fixation component <NUM> passes through the second fixation component <NUM>, as shown in <FIG>. At least a portion of the engaged or coupled spring <NUM> and first fixation component <NUM> are received within the second fixation component <NUM>. The spring <NUM> may include a first end <NUM> for engaging the first fixation component <NUM> and a second end <NUM> for engaging the recess <NUM> in the base member <NUM>, as shown in <FIG>.

The first fixation component <NUM> may include a threaded portion <NUM> at a first end and a stop member or end member <NUM> at a second end, as shown in <FIG>, <FIG>, <FIG> and <FIG>. The threads of the threaded portion <NUM> may extend, for example, from the first end to the stop member <NUM> or, alternatively, from the first end toward the stop member <NUM> along only a portion of the first fixation component <NUM>, as shown in <FIG>, <FIG>, <FIG> and <FIG>. Referring now to <FIG>, the first fixation component <NUM> may also include a drive opening <NUM>. The drive opening <NUM> may be sized and shaped or configured to receive an instrument or driver for coupling and removing the first fixation component <NUM> from articulating member <NUM>, as shown in <FIG>. The drive opening <NUM> may be, for example, hexagonal, square, Phillips or another multi-lobed configuration for coupling with an instrument. The second end of the first fixation component <NUM> may include a recess, spring cavity or spring opening <NUM>, as shown in <FIG>. The recess <NUM> may be, for example, inset into the stop member <NUM> of the first fixation component <NUM>. Further, the recess <NUM> may be sized and shaped or configured to receive the first end <NUM> of the spring <NUM>, as shown in <FIG>.

The second fixation component or base coupler <NUM> is shown in <FIG>, <FIG>, and <FIG>. The second fixation component <NUM> may include a head portion <NUM> at a first end and a body <NUM> extending away from the head portion <NUM> to the second end. The body <NUM> may include threads <NUM> along at least a portion of the body <NUM>. For example, the threads <NUM> may extend from the head portion <NUM> toward the second end on the exterior surface of the second fixation component <NUM> along only a portion of the body <NUM>, as shown in <FIG>, <FIG>, <FIG> and <FIG>. Alternatively, the threads <NUM> may extend from the head portion <NUM> to the second end on the exterior surface of the body <NUM> of the second fixation component <NUM>. The second fixation component <NUM> may also include a drive opening <NUM> on the first end, as shown in <FIG>, for receiving an instrument or driver. The drive opening <NUM> may be, for example, hexagonal, square, Phillips or another multi-lobed configuration for coupling with an instrument. The second fixation component <NUM> may also include an opening or through hole <NUM> extending from the drive opening <NUM> at the first end to the second end, as shown in <FIG>. The opening <NUM> may be, for example, sized and shaped or configured to receive the first fixation component <NUM>, as shown in <FIG>. The drive opening <NUM> may be sized and shaped or configured to allow the threaded portion <NUM> of the first fixation component <NUM> to extend out the first end of the second fixation component <NUM>, as shown in <FIG>. The opening <NUM> may have, for example, a diameter larger than the width of the drive opening <NUM> to prevent the stop member <NUM> of the first fixation component <NUM> from passing through the interior of the second fixation component <NUM>.

A method of assembling the implant <NUM>, not in accordance with the appended claims, is also disclosed. The method may include inserting the first fixation component <NUM> into the opening <NUM> of the second fixation component <NUM>. The method may also include inserting the first end <NUM> of the spring <NUM> into the recess <NUM> of the first fixation component <NUM> to form the coupling member <NUM>. The method may further include inserting the second end <NUM> of the spring <NUM> into the spring opening <NUM> in the base member <NUM> and coupling the threads <NUM> of the body <NUM> of the second fixation member <NUM> with the threads <NUM> in the cavity <NUM> of the base member <NUM>. This arrangement of the coupling portion <NUM> creates a biasing force to push the first fixation component <NUM> out of the second fixation component <NUM> to be able to engage the articulating component <NUM>. Therefore, after securing the coupling member <NUM> to the base member <NUM>, at least a part of the threaded portion <NUM> will extend out of the first end of the second fixation component <NUM>. Optionally, the base member <NUM> and secured coupling member <NUM> may be inserted into the patient and then the articulating member <NUM> may be coupled to the base member <NUM>.

Next, the cavity <NUM> of the articulating member <NUM> may be aligned over the projection <NUM> of the base member <NUM>. Once aligned, the articulating member <NUM> may be coupled to the base member <NUM> by applying a force to the articulating member <NUM> to engage the cavity <NUM> with the projection <NUM>. If necessary, an instrument (not shown) may be used to force the articulating member <NUM> into place on the base member <NUM>. As the articulating member <NUM> engages the base member <NUM>, the spring <NUM> of the coupling member <NUM> may be compressed. Once the desired position of the articulating member <NUM> is achieved on the base member <NUM>, the first fixation component <NUM> may be rotated to thread the threaded portion <NUM> of the first fixation component <NUM> into the threads <NUM> of the articulating member <NUM>. If the base member <NUM> wasn't already inserted into a patient, once the articulating member <NUM> and base member <NUM> are each coupled to the coupling portion <NUM>, the implant <NUM> may be inserted into a patient.

Also disclosed is a method, not in accordance with the appended claims, of using a prosthesis <NUM>. For instance, base member <NUM> according to the embodiments above may be positioned within a scapula. Although described as a reverse shoulder replacement, it should be understood that the base members <NUM> can be positioned in the proximal humerus as well, providing an articulating convex surface in its correct anatomic placement. Next, an articulating member <NUM> as in the above embodiment can be attached to the base member <NUM>, using the projection <NUM> of the base member <NUM>, cavity <NUM> of the articulating member <NUM>, and a coupling portion <NUM> engaging the articulating member <NUM> and the base member <NUM>, as described in greater detail above with reference to <FIG> and which will not be described again here for brevity sake. Once the coupling portion <NUM> is attached to the base portion <NUM> and inserted into a patient, the surgeon is able to couple the articulating member <NUM> to the coupling portion <NUM> and the base portion <NUM> without having to find an opening in the articulating member <NUM> to insert additional screws. The shape and size of the cavity <NUM> in the articulating member <NUM> may correspond to the shape and size of the projection <NUM> of the base member <NUM> to, for example, assist with preventing malalignment during insertion of the implant.

As shown in <FIG>, the articulating member <NUM> may be of the type described above with reference to <FIG>. As described in greater detail above and which will not be described again here for brevity sake, the articulating member <NUM> may include an articulating surface or exterior surface <NUM> and an interior surface, flat side, or engagement portion <NUM> with the outer lip or lip <NUM>, the recess <NUM>, and the cavity <NUM>, as shown in <FIG> and <FIG>. The articulating member <NUM> may also include a threaded portion or threads <NUM>.

The base member or base portion <NUM> is shown in <FIG>. The base member <NUM> includes a plate portion <NUM> with a top surface <NUM> and a bottom surface <NUM>. The plate portion <NUM> may also include a plurality of openings or through holes <NUM> extending through the plate portion <NUM> from a top surface <NUM> to the bottom surface <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The base member <NUM> also includes a projection <NUM> extending away from the top surface <NUM> of the plate portion <NUM>, as shown in <FIG> and <FIG>. The projection <NUM> may be positioned, for example, generally centered on the top surface <NUM> of the plate portion <NUM> with the plurality of openings <NUM> positioned around the exterior surface of the projection <NUM>, as shown in <FIG> and <FIG>. The projection <NUM> may be, for example, tapered as it extends away from the top surface <NUM> of the base member <NUM>. The projection <NUM> may have a taper, for example, ranging between approximately <NUM>° to <NUM>°, as the projection <NUM> extends away from the base member <NUM>. The projection <NUM> may have, for example, a height and a first width or diameter positioned where the projection <NUM> couples to the plate portion <NUM> and the height may be larger than the first diameter.

The projection <NUM> may also include a cavity or opening <NUM> extending into the projection <NUM> from a first or top end, as shown in <FIG> and <FIG>. With continued reference to <FIG> and <FIG>, the cavity <NUM> may further include a recess or spring opening <NUM> in a bottom surface of the cavity <NUM>. The recess <NUM> may, for example, extend into the top surface <NUM> of the plate portion <NUM>, as shown in <FIG>. The cavity <NUM> may also include a retaining member or rim <NUM>, for example, positioned near a top of the interior wall of the cavity <NUM>. The retaining member <NUM> may, for example, be chamfered or angled on a top surface and flat or perpendicular to the interior side wall of the cavity <NUM>, as shown in <FIG>. The opening extending through the retaining member <NUM> may include a diameter smaller than the diameter of the cavity <NUM> to engage the coupling portion <NUM> for securing the articulating member <NUM> to the base member <NUM>.

The base member <NUM> further includes a stem <NUM>, as shown in <FIG>. The stem <NUM> extends away from the bottom surface <NUM> of the plate portion <NUM>. The stem <NUM> may be, for example, centered on the bottom surface <NUM> of the plate portion <NUM>, as shown in <FIG>. Further, the stem <NUM> may be aligned with the projection <NUM>, as shown in <FIG>. The stem <NUM> may also, be positioned centered between all of the openings <NUM>, as shown in <FIG>. In oneembodiment, the stem <NUM> is offset as described in greater detail above with respect to stem <NUM> and which will not be described again here for brevity sake. The stem <NUM> may further include an opening <NUM> extending from the distal end into the stem <NUM>, as shown in <FIG> and <FIG>. As shown in <FIG>, the opening <NUM> may be, for example, tapered as the opening <NUM> extends toward the plate portion <NUM>.

Referring now to <FIG>, the coupling portion <NUM> is shown. The coupling portion <NUM> includes a securement member or locking bolt <NUM>, a spring or elastic member <NUM>, and an engagement member <NUM>. The securement member <NUM> may include a first portion <NUM> positioned at a first end, a second portion <NUM> positioned at a second end, and an intermediate portion <NUM> positioned between the first portion <NUM> and the second portion <NUM>. The first portion <NUM> may include threads <NUM> positioned along, for example, at least a section of the first portion <NUM> between the first end and the intermediate portion <NUM>. The second portion <NUM> may have a diameter, for example, to receive the spring <NUM>. The intermediate portion <NUM> may include, for example, a first protrusion <NUM> extending circumferentially away from the body of the securement member <NUM> and a second protrusion <NUM> extending circumferentially away from the body of the securement member <NUM>. The first protrusion <NUM> may be spaced apart from the second protrusion <NUM> forming a recess or channel <NUM> between the protrusions <NUM>, <NUM>. The recess or channel <NUM> may be, for example, sized to receive the engagement member <NUM>.

Referring now to <FIG> and <FIG>, the engagement member <NUM> may include a through opening <NUM> extending from a top surface to a bottom surface of the engagement member <NUM> and a slot <NUM> extending from an exterior surface into the opening <NUM>. The engagement member <NUM> may be, for example, a snap ring, split washer, or the like to be positioned around the body of the securement member <NUM> and may deform when inserted into the base member <NUM>.

As shown in <FIG>, the spring <NUM> may include a first end <NUM>, a second end <NUM>, and a through hole <NUM> extending from the first end <NUM> to the second end <NUM>. The through hole <NUM> of the spring <NUM> may receive the second portion <NUM> of the securement member <NUM>, as shown in <FIG> and <FIG>. The first end <NUM> may engage a bottom surface of the second protrusion <NUM> and the second end <NUM> may engage the recess <NUM> in the base member <NUM>, as shown in <FIG> and <FIG>.

A method, not in accordance with the appended claims, of assembling the implant <NUM> is also disclosed. The method may include forming the coupling member <NUM>. Forming the coupling member <NUM> may include inserting the second portion <NUM> of the securement member <NUM> into the through hole <NUM> of the spring <NUM> at the first end <NUM>. Forming the coupling member <NUM> may also include aligning the slot <NUM> of the engagement member <NUM> with the recess <NUM> in the securement member <NUM> and inserting the engagement member <NUM> into the recess <NUM> of the securement member <NUM>. The method may also include inserting the second portion <NUM> of the securement member <NUM> into the cavity <NUM> in the base member <NUM>. As the second portion <NUM> is inserted into the cavity <NUM>, the second end <NUM> of the spring <NUM> may be inserted into the recess <NUM> in the base member <NUM> and the engagement member <NUM> may be inserted into the cavity <NUM> past the retaining member <NUM>. As the engagement member <NUM> is inserted into the cavity <NUM>, the engagement member <NUM> may deflect to pass the retaining member <NUM>. Once the engagement member <NUM> passes the retaining member <NUM>, the engagement member <NUM> will expand to the original size and secure the securement member <NUM> to the base member <NUM>, as shown in <FIG> and <FIG>. The securement member <NUM> may translate within the cavity <NUM> with respect to the force applied to the spring <NUM> until the engagement member <NUM> engages the retaining member <NUM>. At least part of the first portion <NUM> will extend out from the projection <NUM> of the base member <NUM> to engage the articulating member <NUM>, as shown in <FIG> and <FIG>. Optionally, the base member <NUM> and secured coupling member <NUM> may be inserted into the patient and then the articulating member <NUM> may be coupled to the base member <NUM>.

Next, the method may include aligning and inserting the projection <NUM> of the base member <NUM> into the cavity <NUM> of the articulating member <NUM>. A force may be applied to the articulating member <NUM> to engage the cavity <NUM> with the projection <NUM>. If necessary, an instrument (not shown) may be used to force the articulating member <NUM> into place on the base member <NUM>. As the articulating member <NUM> engages the base member <NUM>, the spring <NUM> of the coupling member <NUM> may be compressed. Once the desired position of the articulating member <NUM> is achieved on the base member <NUM>, the first portion <NUM> of the securement member <NUM> may be engaged and rotated to couple the threads <NUM> of the securement member <NUM> to the threaded portion <NUM> of the articulating member <NUM>. Although not shown, the first portion <NUM> may include a driver opening, such as driver opening <NUM> of implant <NUM>, which will not be described again here for brevity sake. If the base member <NUM> wasn't already inserted into a patient, once the articulating member <NUM> is attached to the coupling portion <NUM> and base member <NUM>, the implant <NUM> may be inserted into a patient.

Also disclosed is a method, not in accordance with the appended claims, of using a prosthesis <NUM>. For instance, a base member <NUM> according to the embodiment above may be positioned within a scapula. Although described as a reverse shoulder replacement, it should be understood that the base member <NUM> can be positioned in the proximal humerus as well, providing an articulating convex surface in its correct anatomic placement. Next, an articulating member <NUM> as in the above embodiments can be attached to the base member <NUM>, using the projection <NUM> of the base member <NUM>, cavity <NUM> of the articulating member <NUM>, and the coupling portion <NUM> engaging the articulating member <NUM> and the base member <NUM>, as described in greater detail above with reference to <FIG> and which will not be described again here for brevity sake. Once the coupling portion <NUM> is coupled to the base portion <NUM> and inserted into a patient, the surgeon is able to attach the articulating member <NUM> to the coupling portion <NUM> and the base portion <NUM> without having to find an opening in the articulating member <NUM> to insert additional screws. The shape and size of the cavity <NUM> in the articulating member <NUM> may correspond to the shape and size of the projection <NUM> of the base member <NUM> to, for example, assist with preventing malalignment during insertion of the implant.

As may be recognized by those of ordinary skill in the art based on the teachings herein, numerous changes and modifications may be made to the above-described and other embodiments of the present invention without departing from the scope of the invention as defined by the appended claims. The articulating member or spherical shaped articulating component, base member or base plate, coupling portion or fixation component, and other components of the device and/or system as disclosed in the specification, including the accompanying abstract and drawings, may be replaced by alternative component(s) or feature(s), such as those disclosed in another embodiment, which serve the same, equivalent or similar purpose as known by those skilled in the art to achieve the same, equivalent or similar results by such alternative component(s) or feature(s) to provide a similar function for the intended purpose. In addition, the devices and systems may include more or fewer components or features than the embodiments as described and illustrated herein. For example, the components and features of <FIG>, <FIG>, and <FIG> may all be used interchangeably and in alternative combinations as would be modified or altered by one of skill in the art. Accordingly, this detailed description of the currently-preferred embodiments is to be taken in an illustrative, as opposed to limiting of the invention.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the scope of the invention as defined by the following claims. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the various embodiments without departing from their scope. While the dimensions and types of materials described herein are intended to define the parameters of the various embodiments, they are by no means limiting and are merely exemplary. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the various embodiments should, therefore, be determined with reference to the appended claims. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein. " Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Also, the term "operably connected" is used herein to refer to both connections resulting from separate, distinct components being directly or indirectly coupled and components being integrally formed (i.e., monolithic). It is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

It will be further understood that the terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has", and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a method or device that "comprises," "has," "includes," or "contains" one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that "comprises," "has," "includes," or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the disclosure may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claim 1:
An implant (<NUM>, <NUM>, <NUM>), comprising:
a base member (<NUM>, <NUM>, <NUM>) comprising:
a plate portion (<NUM>, <NUM>, <NUM>) having a first side (<NUM>, <NUM>, <NUM>) and an opposed second side (<NUM>, <NUM>, <NUM>),
a projection (<NUM>, <NUM>, <NUM>) extending from the first side of the plate portion, the projection being offset from a center (<NUM>) of the plate portion, and
a stem (<NUM>, <NUM>, <NUM>) extending from the second side (<NUM>, <NUM>, <NUM>) of the plate portion, the stem being positioned offset from the center (<NUM>) of the plate portion (<NUM>, <NUM>, <NUM>) and sized and configured to secure the base member in bone;
an articulating member (<NUM>, <NUM>) defining an articulation member of cavity (<NUM>, <NUM>) and a hole (<NUM>, <NUM>), the cavity sized and configured to receive the projection extending from the first side of the plate portion, and the hole extending through the cavity; and
a coupling portion (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) sized and configured to be received in the hole defined by the articulating member for securing the base member to the articulating member.