Patent Description:
The field of the invention is the devices that facilitate implanting the glenoid implants. In particular, the invention has links to implants for glenoids having non-uniform erosion and devices that facilitate implanting the same.

In a healthy shoulder joint, the head of the humerus interacts with the glenoid of the scapula to form a "ball and socket" joint. The humeral head abuts and articulates with the glenoid to provide a wide range of motion. In an unhealthy shoulder joint, the interaction between the glenoid and the humerus is compromised, requiring repair or replacement.

In some unhealthy shoulder joints, different portions of the glenoid can experience different amounts of bone erosion. For example and referring to <FIG>, a glenoid <NUM> may include a posterior portion <NUM> that has a significant amount of erosion and an anterior portion <NUM> that has little or no erosion. Such a glenoid is commonly referred to as a "type-B2" glenoid. As another example, a glenoid may include a supero-posterior portion that has a significant amount of erosion and an infero-anterior portion that has little or no erosion. As yet another example, a glenoid may include an infero-posterior portion that has a significant amount of erosion and a supero-anterior portion that has little or no erosion. In any of these cases, a surgeon may need to remove a significant amount of bone, specifically, cortical bone of the relatively healthy portions of the glenoid, to accommodate typical glenoid implants.

Previously, glenoid components were developed that were specifically intended to be used with type-B2 glenoids and address the issues of typical glenoid components described above. Some of these glenoid components, for example, include a scapula-facing surface in which different portions of the surface are disposed at different "elevations". These components also include a transversely-extending surface that connects the different portions of the scapula-facing surface. These surfaces provide the glenoid component with a "stepped" appearance. However, these glenoid components nevertheless require a significant amount of bone removal and typically violate the subchondral plate. In addition, it is relatively difficult to remove bone to form an appropriately shaped surface for receiving a step-shaped glenoid component, and a surgeon must frequently insert a trial implant to check the fit with the surface.

<FIG> illustrate a glenoid <NUM> at different stages of traditional on-axis reaming. <FIG> illustrates a glenoid <NUM> with a portion of bone <NUM> that has deteriorated from the posterior portion <NUM>. <FIG> illustrates a reamer <NUM> approaching the glenoid <NUM> along a longitudinal axis L of the glenoid <NUM>. Portion <NUM> indicates the portion of bone to be removed using the reamer <NUM>. As shown in <FIG>, following on-axis reaming, a significant portion <NUM> of the glenoid <NUM> has been unnecessarily removed from both the posterior portion <NUM> and the anterior portion <NUM>.

As another example, <FIG> illustrate a glenoid <NUM> following off-axis reaming at different angles. Traditionally, to accomplish off-axis reaming, the entire reamer <NUM> is introduced into the body at an angle (i.e., <NUM> degrees, <NUM> degrees, or <NUM> degrees) relative to the longitudinal axis L of the bone. However, as shown in <FIG>, a greater portion of the anterior portion <NUM> is still unnecessarily removed from the glenoid <NUM> than is necessary for the implantation of glenoid components created for type-B2 glenoids.

<FIG> illustrate yet another glenoid <NUM> following preparation of the bone for the insertion of a GLOBAL® STEPTECH® Anchor Peg Glenoid. In this method, a significant portion of the posterior portion <NUM> of the glenoid <NUM> has been unnecessarily removed in a stepped manner. Accordingly, there is a need for a device that minimizes the amount of bone removed.

Others of these glenoid components, for example, include a scapula-facing surface that has a constant slope. However, forces acting on the proximal or articulation surface of these components urge the sloped scapula-facing surface to slide over the prepared glenoid. This action, in turn, applies shear forces to posts or anchors that extend from the scapula-facing surface and couple to the bone. These glenoid components also present challenges to surgeons. Specifically, the reaming path for preparing the glenoid is typically across the glenoid.

<CIT> concerns an orthopedic reamer driver including a tubular housing having at least one first positioning feature. A driveshaft within the housing has a drive end. A variable angle cap is pivotally coupled with the housing adjacent the drive end. The variable angle cap includes at least one leg extending along a side of the housing. Each leg has a second positioning feature selectively engaging and disengaging with a corresponding first positioning feature at a selected one of a plurality of angular positions. Each second positioning feature maintains the variable angle cap at the selected angular position when engaged with the corresponding first positioning feature. A variable angle joint is coupled to the drive end, and a reamer drive head is coupled to the variable angle joint.

In some embodiments, a glenoid component for coupling to a scapula of a subject includes a body. The body includes an articulation surface adapted to articulate with a humeral component, and the body further includes a distal surface adapted to face the glenoid of the scapula. The distal surface includes a base surface portion including a first convex surface adapted to face a first portion of the glenoid. The distal surface further includes an augmented surface portion including a second convex surface adapted to face a second portion of the glenoid. The base surface portion and the augmented surface portion are connected therebetween by an interface. The first convex surface may include a first radius of curvature and the second convex surface may include a second radius of curvature. In particular embodiments, the first and second radius of curvature may be the same. The first convex surface may extend from the interface to an anterior portion of the glenoid implant. The second convex surface may extend from the interface to at least one of a posterior portion, supero-posterior portion or an infero-posterior portion of the implant.

In some embodiments, a device for removing bone from a glenoid of a subject includes a frame adapted to be manipulated by a user and a reaming head including a reaming surface. A drive shaft is rotatably supported by and extends through the frame and has a distal end coupled with the reaming head. The drive shaft is rotatable about a drive shaft axis at the distal end. A bearing is supported by the frame and the bearing is capable of providing a rotational axis of the reaming head that is non-parallel to the drive shaft axis at the distal end.

In some embodiments, a device for removing bone from a glenoid of a subject includes a frame that is adapted to be manipulated by a user. A drive shaft is rotatably supported by the frame and adapted to be rotatably driven about a drive axis. A reaming head includes at least one reaming edge adapted to engage the glenoid of the subject. The reaming head is adapted to be rotatably driven about a reaming axis by the drive shaft, and the reaming axis is non-parallel to the drive axis.

In some embodiments, a device for removing bone from a glenoid of a subject includes a frame adapted to be manipulated by a user and a reaming head including a reaming surface. A drive shaft is rotatably supported by and extends through the frame and has a distal end coupled with the reaming head. The drive shaft is adapted to be rotatably driven about a drive shaft axis. A guard member is coupled to a distal portion of the frame. The guard member is configured to inhibit a portion of the reaming surface from engaging bone.

In some embodiments, a device for removing bone from a glenoid of a subject includes a frame adapted to be manipulated by a user and a reaming head including a reaming surface. A cannulated drive shaft is rotatably supported by and extends at least partially through the frame and has a distal end coupled with the reaming head. The drive shaft is adapted to be rotatably driven about a drive shaft axis. The device has a first configuration to rotate the reaming head about a first reaming axis when the reaming head is in a first orientation. The device has a second configuration to rotate the reaming head about a second reaming axis when the reaming head is in a second orientation.

While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications falling within the scope of the invention as defined by the appended claims.

<FIG> illustrate an exemplary glenoid component or implant <NUM> according to embodiments. The glenoid component <NUM> is adapted to be positioned between the scapula of a subject (not shown) and a humeral component. The glenoid component <NUM> is also adapted to articulate with the humeral component. The humeral component may be a humeral prosthesis secured to the humerus of the subject or an anatomical humeral head of the subject (see, for example, the humeral head <NUM> shown in <FIG>).

The glenoid component <NUM> includes a body <NUM> having a proximal or articulation surface <NUM>. The articulation surface <NUM> is concave and adapted to engage the humeral component. The articulation surface <NUM> receives at least a portion of the humeral component within the concavity defined by the articulation surface <NUM>.

Opposite the articulation surface <NUM>, the body <NUM> includes a distal or scapula-facing surface <NUM>. In some embodiments, the distal surface <NUM> supports one or more securing and/or stabilizing anchors, pins, or posts <NUM> (referred to herein as anchors). The anchors <NUM> may be received in pre-drilled holes in the scapula (not shown). The anchors <NUM> may have generally cylindrical shapes, and the ends opposite the body <NUM> of the glenoid component <NUM> may be conical or frusto-conical to facilitate insertion into the pre-drilled holes formed in the scapula. The anchors <NUM> may have various lengths and/or different lengths relative to each other.

The anchors <NUM> may have features that facilitate securement to the scapula. For example, one or more of the anchors <NUM> may include one or more radially-outwardly extending fins <NUM>. As another example, one or more of the anchors <NUM> may include one or more transversely extending grooves <NUM>.

The anchors <NUM> may be arranged on the distal surface <NUM> in various manners. For example and as shown in the figures, one anchor <NUM> may be centrally positioned, one anchor <NUM> may be superiorly positioned, and two anchors <NUM> may be inferiorly positioned.

In some embodiments, the anchors <NUM> may be arranged and configured in any of the manners described in <CIT>. In other embodiments one or more anchors may include a keel, finned keel, or other structures. See for example <CIT>.

The distal surface <NUM> of the glenoid component <NUM> is adapted to face the glenoid of the subject. In some embodiments, the glenoid may be an anatomical type-B2 glenoid (see, for example, the glenoid <NUM> shown in <FIG>) or a type-B2 glenoid that is at least partially prepared for receiving the glenoid component <NUM> (for example, by removing bone from the glenoid).

The distal surface <NUM> of the glenoid component <NUM> includes different portions that face different portions of the glenoid. The different portions of the glenoid may have experienced different amounts of bone erosion. Specifically, the distal surface <NUM> includes a base surface portion <NUM> that is adapted to face a first portion of the glenoid. In some embodiments, the first portion is a relatively healthy (that is, having little or no bone erosion) anterior portion of the glenoid. The anterior portion of the glenoid may be an anatomical surface or a surface that is at least partially prepared for receiving the glenoid component <NUM>. The distal surface <NUM> also includes an augmented surface portion <NUM> that is adapted to face a second portion of the glenoid. In some embodiments, the second portion is a relatively unhealthy (that is, having a significant amount of bone erosion) posterior portion of the glenoid. The posterior portion of the glenoid may be an anatomical surface or a surface that is at least partially prepared for receiving the glenoid component <NUM>.

As shown most clearly in <FIG>, the augmented surface portion <NUM> is generally disposed further from the articulation surface <NUM> than the base surface portion <NUM>. Stated another way, the body <NUM> of the glenoid component <NUM> is relatively thin between base surface portion <NUM> and the articulation surface <NUM>. In contrast, the body <NUM> of the glenoid component <NUM> is relatively thick between the augmented surface portion <NUM> and the articulation surface <NUM>.

In some embodiments, the base surface portion <NUM> is a convex surface. The base surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a transverse plane <NUM> that extends through the articulation surface <NUM>, the base surface portion <NUM>, and the augmented surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction and substantially bisecting each of the surfaces <NUM>, <NUM>, and <NUM>; see <FIG>). The base surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a longitudinal plane <NUM> that extends through the articulation surface <NUM> and the base surface portion <NUM> and is disposed apart from the augmented surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction, substantially perpendicular to the transverse plane <NUM>, substantially bisecting the base surface portion <NUM>, and not intersecting with the augmented surface portion <NUM>; see <FIG>).

In some embodiments, the augmented surface portion <NUM> is a convex surface. The augmented surface portion <NUM> may have a curved shape (for example, an arcuate shape) in the transverse plane <NUM> (see <FIG>). The augmented surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a longitudinal plane <NUM> that extends through the articulation surface <NUM> and the augmented surface portion <NUM> and is disposed apart from the base surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction, substantially parallel to the longitudinal plane <NUM>, substantially bisecting the augmented surface portion <NUM>, and not intersecting with the base surface portion <NUM>; see <FIG>).

The augmented surface portion <NUM> and the base surface portion <NUM> intersect at an interface <NUM>. In other words, the base surface portion <NUM> and the augmented surface portion <NUM> are connected by or intersect at the interface <NUM>. In some embodiments, the augmented surface portion <NUM> and the base surface portion <NUM> define an obtuse angle <NUM> at the interface <NUM> (see <FIG>). More specifically, the base surface portion <NUM> has a first convex surface 116a, extending from the interface <NUM> to an anterior portion of the implant and adapted to face a first portion of the glenoid. The augmented surface portion <NUM> has a second convex surface 118a, extending from the interface to at least one of a posterior portion, a supero-posterior portion, or an infero portion of the glenoid implant and adapted to face a second portion of the glenoid. Stated another way, the base surface portion <NUM> has a first, relatively-gradual slope toward the interface <NUM> and the augmented surface portion <NUM> has a second, relatively-inclined slope toward the interface <NUM>. The first convex surface 116a has a first radius of curvature and the second convex surface 118a has a second radius of curvature. The first radius of curvature and the second radius of curvature may be the same or different. In some embodiments, the interface <NUM> substantially extends in a direction parallel to the longitudinal planes <NUM> and <NUM> (see <FIG>). That is, the interface <NUM> may curve slightly relative to the planes <NUM> and <NUM> due to the shapes of the augmented surface portion <NUM> and the base surface portion <NUM>.

<FIG> illustrate an exemplary glenoid component or implant <NUM> according to embodiments. The glenoid component <NUM> is adapted to be positioned between the scapula of a subject and a humeral component. The glenoid component <NUM> is also adapted to articulate with the humeral component. The humeral component may be a humeral prosthesis secured to the humerus of the subject or an anatomical humeral head of the subject (see, for example, the humeral head <NUM> shown in <FIG>).

Opposite the articulation surface <NUM>, the body <NUM> includes a distal or scapula-facing surface <NUM>. In some embodiments, the distal surface <NUM> supports one or more securing and/or stabilizing anchors, pins, or posts <NUM> which may have the same features and/or be arranged in the same manner as the anchors <NUM> described above.

The distal surface <NUM> of the glenoid component <NUM> is adapted to face the glenoid of the subject. In some embodiments, the glenoid may be an anatomical glenoid that has significant supero-posterior erosion and little or no infero-anterior erosion or such a glenoid that is at least partially prepared for receiving the glenoid component <NUM> (for example, by removing bone from the glenoid).

The distal surface <NUM> of the glenoid component <NUM> includes different portions that face different portions of the glenoid. Specifically, the distal surface <NUM> includes a base surface portion <NUM> that is adapted to face the infero-anterior portion of the glenoid. The distal surface <NUM> also includes an augmented surface portion <NUM> that is adapted to face the supero-posterior portion of the glenoid.

In some embodiments, the base surface portion <NUM> is a convex surface. The base surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a plane <NUM> that extends through the articulation surface <NUM>, the base surface portion <NUM>, and the augmented surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction and substantially bisecting each of the surfaces <NUM>, <NUM>, and <NUM>; see <FIG>). The base surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a plane <NUM> that extends through the articulation surface <NUM> and the base surface portion <NUM> and is disposed apart from the augmented surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction, substantially bisecting the base surface portion <NUM>, and not intersecting with the augmented surface portion <NUM>; see <FIG>).

In some embodiments, the augmented surface portion <NUM> is a convex surface. The augmented surface portion <NUM> may have a curved shape (for example, an arcuate shape) in the plane <NUM> (see <FIG>). The augmented surface portion <NUM> may have a curved shape (for example, an arcuate shape) in a longitudinal plane <NUM> that extends through the articulation surface <NUM> and the augmented surface portion <NUM> and is disposed apart from the base surface portion <NUM> (that is, a plane extending through the body <NUM> in a thickness direction, substantially bisecting the augmented surface portion <NUM>, and not intersecting with the base surface portion <NUM>; see <FIG>).

The augmented surface portion <NUM> and the base surface portion <NUM> intersect at an interface <NUM>. In other words, the base surface portion <NUM> and the augmented surface portion <NUM> are connected by or intersect at interface <NUM>. In some embodiments, the augmented surface portion <NUM> and the base surface portion <NUM> define an obtuse angle <NUM> at the interface <NUM> (see <FIG>). More specifically, the base surface portion <NUM> has a first convex surface 216a, extending from the interface <NUM> to an anterior portion of the implant and adapted to face a first portion of the glenoid. The augmented surface portion <NUM> has a second convex surface 218a, extending from the interface <NUM> to at least one of a posterior portion, a supero-posterior portion, or an infero portion of the glenoid implant and adapted to face a second portion of the glenoid. Stated another way, the base surface portion <NUM> has a first, relatively-gradual slope toward the interface <NUM> and the augmented surface portion <NUM> has a second, relatively-inclined slope toward the interface <NUM>. The first convex surface 216a has a first radius of curvature and the second convex surface 218a has a second radius of curvature. The first radius of curvature and the second radius of curvature may be the same or different. In some embodiments, the interface <NUM> substantially extends in a direction parallel to the planes <NUM> and <NUM> (see <FIG>). That is, the interface <NUM> may curve slightly relative to the planes <NUM> and <NUM> due to the shapes of the augmented surface portion <NUM> and the base surface portion <NUM>.

The distal surface <NUM> of the glenoid component <NUM> is adapted to face the glenoid of the subject. In some embodiments, the glenoid may be an anatomical glenoid that has significant infero-posterior erosion and little or no supero-anterior erosion or such a glenoid that is at least partially prepared for receiving the glenoid component <NUM> (for example, by removing bone from the glenoid).

The distal surface <NUM> of the glenoid component <NUM> includes different portions that face different portions of the glenoid. Specifically, the distal surface <NUM> includes a base surface portion <NUM> that is adapted to face the supero-anterior portion of the glenoid. The distal surface <NUM> also includes an augmented surface portion <NUM> that is adapted to face the infero-posterior portion of the glenoid.

The augmented surface portion <NUM> and the base surface portion <NUM> intersect at an interface <NUM>. In other words, the base surface portion <NUM> and the augmented surface portion <NUM> are connected by the interface <NUM>. In some embodiments, the augmented surface portion <NUM> and the base surface portion <NUM> define an obtuse angle <NUM> at the interface <NUM> (see <FIG>). More specifically, the base surface portion <NUM> has a first convex surface 316a, extending from the interface <NUM> to an anterior portion of the implant and adapted to face a first portion of the glenoid. The augmented surface portion <NUM> has a second convex surface 318a, extending from the interface <NUM> to at least one of a posterior portion, a supero-posterior portion, or an infero portion of the glenoid implant and adapted to face a second portion of the glenoid. Stated another way, the base surface portion <NUM> has a first, relatively-gradual slope toward the interface <NUM> and the augmented surface portion <NUM> has a second, relatively-inclined slope toward the interface <NUM>. The first convex surface 316a has a first radius of curvature and the second convex surface 318a has a second radius of curvature. The first radius of curvature and the second radius of curvature may be the same or different. In some embodiments, the interface <NUM> substantially extends in a direction parallel to the planes <NUM> and <NUM> (see <FIG>). That is, the interface3 may curve slightly relative to the planes <NUM> and <NUM> due to the shapes of the augmented surface portion <NUM> and the base surface portion <NUM>.

<FIG> illustrate an exemplary reaming device <NUM> according to the invention. The reaming device <NUM> may prepare, or remove, bone from the glenoid of the subject and facilitates subsequently implanting a glenoid component, such as one of the glenoid components <NUM>, <NUM>, or <NUM> described above.

The reaming device <NUM> includes a housing or frame <NUM> that may be manipulated by user (for example, a surgeon) to appropriately position the reaming device <NUM> relative to the glenoid of the subject. The frame <NUM> rotatably supports a drive coupling <NUM> at a proximal end. The drive coupling <NUM> is adapted to detachably couple to a prime mover (such as a hand-held drill or the like). The drive coupling <NUM> also connects to and rotatably drives a drive shaft <NUM> that is rotatably supported by the frame <NUM>. The drive shaft <NUM> can be straight, such that the drive shaft <NUM> extends along and rotates about a drive axis <NUM>. The drive shaft <NUM> transmits rotational motion from the proximal end of the reaming device <NUM> to an opposite, distal end of the device <NUM>, for example because the distal end of the drive shaft <NUM> can be at least partially disposed within a reaming head <NUM>. As shown in <FIG>, the drive shaft <NUM> can be cannulated, so the reaming device <NUM> can be delivered over a guide pin (e.g., a K-wire). The cannulated drive shaft <NUM> can have a distal opening located adjacent to and/or distal of a distal-most portion of a reaming surface of the reaming head <NUM>. The distal opening of the cannulated drive shaft <NUM> may be distal of an axis of angulation of the reaming head <NUM>.

At the distal end of the device <NUM>, the frame <NUM> includes a bearing or bushing <NUM> that can be adjusted to select the angle of a reaming axis <NUM> of the reaming head <NUM>, such that the reaming axis <NUM> can be parallel or non-parallel to the drive shaft axis <NUM> at a distal end of the drive shaft <NUM>. The bearing <NUM> facilitates adjustment of the angle of the reaming head <NUM>, such that when the drive shaft <NUM> rotates the reaming head <NUM>, the reaming head <NUM> engages the bone asymmetrically relative to an axis extending longitudinally through the distal end of the drive shaft <NUM> to ream the bone asymmetrically relative to the axis. The reaming axis <NUM> intersects with and can be disposed non-parallel to the drive axis <NUM> of the shaft <NUM>, for example within the reaming head <NUM>. As such, the reaming head <NUM> may be referred to as "inclined" or "sloped" relative to the frame <NUM> in some configurations. In some embodiments and as described in further detail below, the bearing <NUM> may be pivotally supported by the remainder of the frame <NUM> about an axis <NUM> that is substantially perpendicular to both the reaming axis <NUM> and the drive axis <NUM>. As a result, an angle <NUM> between the reaming axis <NUM> and the drive axis <NUM> may be selectively adjusted between two or more orientations (e.g., two orientations, three orientations, four orientations, or more). For example, the reaming device <NUM> can have a first configuration to rotate the reaming head <NUM> about a first reaming axis when the reaming head <NUM> is in a first orientation and a second configuration to rotate the reaming head <NUM> about a second reaming axis when the reaming head <NUM> is in a second orientation. For example, the first reaming axis can be substantially aligned with the drive shaft axis <NUM>, and the second reaming axis can be at a non-parallel angle relative to the drive shaft axis <NUM>. As another example, the first reaming axis can be at a first non-parallel angle relative to the drive shaft axis (e.g., about <NUM> degrees), and the second reaming axis can be at a second non-parallel angle relative to the drive shaft axis <NUM> (e.g., about <NUM> degrees). Unlike traditional approaches to reaming (see, e.g., <FIG>), the ability to adjust the angle <NUM> between the reaming axis <NUM> and the drive axis <NUM> enables the user to avoid removing excess bone, e.g., to only remove the necessary portions of the bone.

The reaming head <NUM> includes a base <NUM> (see <FIG>) that connects to the bearing <NUM>. The base <NUM> also supports one or more reaming elements <NUM>, each of which includes a reaming edge or surface <NUM>. When the reaming head <NUM> rotates, the reaming edges <NUM> may engage and prepare bone (that is, shape the bone) for subsequently receiving a glenoid component, such as one of the glenoid components <NUM>, <NUM>, or <NUM> described above. In some embodiments, each of the reaming edges <NUM> has an outwardly curved shape (for example, an arcuate shape) such that the reaming head <NUM> forms a concave surface in the bone for subsequently receiving the glenoid component.

The reaming device <NUM> may include a guard or guard member <NUM> removably coupled to a distal portion of the frame <NUM>. The guard member <NUM> can include a generally C-shaped member such that a distal portion of the guard member <NUM> is disposed distal to the reaming head <NUM>. The guard member <NUM> can be shaped such that a plane extending through the distal portion of the guard member <NUM> is at an angle relative to the drive axis <NUM>. As such, the guard <NUM> inhibits the upper portion of the reaming head <NUM> from engaging bone during a reaming procedure. The guard <NUM> is disposed apart from an opposite lower portion of the reaming head <NUM> (not shown). As such, the lower portion of the reaming head <NUM> engages and prepares bone during a reaming procedure. The guard <NUM> may include an attachment element or feature (for example, a threaded hole <NUM>) that detachably mounts a guide post <NUM>. The guide post <NUM> may be used to guide advancement of the reaming device <NUM> during a reaming procedure.

The reaming head <NUM> is rotatably driven by the drive shaft <NUM> through a coupling mechanism <NUM>, e.g., a pivot coupling (see <FIG>). The coupling mechanism <NUM> can be a separate component from the reaming head <NUM> that is disposed laterally between the reaming head <NUM> and the distal end of the drive shaft <NUM>. Although, in other embodiments, the coupling mechanism <NUM> may be a component of the reaming head <NUM>.

The coupling mechanism <NUM> facilitates rotation of the drive shaft <NUM> and/or the reaming head <NUM> about the reaming axis <NUM>. The reaming axis <NUM> may be non-parallel to the drive shaft axis <NUM>. In some embodiments and as shown in the figures, the coupling mechanism <NUM> includes a generally sphere-shaped element <NUM> at the distal end of the drive shaft <NUM>. The sphere-shaped element <NUM> includes one or more slots <NUM>. The slots <NUM> may have arcuate shapes and may generally extend in the direction of the drive axis <NUM>. Each slot <NUM> translatably receives a post or pin <NUM> supported by reaming head <NUM>. The posts <NUM> and the reaming head <NUM> are rotatably driven by the drive shaft <NUM> due to engagement between the sphere-shaped element <NUM> and the posts <NUM>. As the reaming head <NUM> rotates, the posts <NUM> move upwardly and downwardly in the slots <NUM>, once per revolution, due to the non-parallel arrangement of the reaming axis <NUM> and the drive axis <NUM>.

In some embodiments, the reaming device <NUM> includes a locking mechanism <NUM> that couples the reaming head <NUM> to the frame <NUM>. A user may move the locking mechanism <NUM> between a locked position and an unlocked position. In the locked position, the locking mechanism <NUM> inhibits adjustment of the angle <NUM> between the drive axis <NUM> and the reaming axis <NUM>. In the unlocked position, the locking mechanism <NUM> permits adjustment of the angle between the drive axis <NUM> and the reaming axis <NUM>.

In some embodiments and as shown in the figures, the locking mechanism <NUM> includes a handle <NUM> that may be manipulated by the user to move between the locked position and the unlocked position. Specifically, the handle <NUM> may be displaced in a direction that is substantially perpendicular to the drive axis <NUM>. The handle <NUM> connects to a rod <NUM> that is translatably supported by the frame <NUM>. Opposite the handle <NUM>, the rod <NUM> connects to a tooth <NUM>. The tooth <NUM> is removably received in one of a plurality of notches <NUM> (see <FIG>) defined by the bearing <NUM>. The bearing <NUM> may include three notches <NUM>, although the bearing <NUM> may alternatively include different numbers of notches <NUM>. In any case, each notch <NUM> defines an angle, or orientation, at which the reaming axis <NUM>, and the reaming head <NUM>, may be disposed relative to the drive axis <NUM>. The reaming axis <NUM> and the reaming head <NUM> may be disposed, for example, at angles of <NUM> degrees (see <FIG>), <NUM> degrees (not shown), and <NUM> degrees (see <FIG>) relative to the drive axis <NUM>.

In the locked position, the tooth <NUM> is received in one of the notches <NUM> to inhibit adjustment of the angle <NUM> between the drive axis <NUM> and the reaming axis <NUM>. To move to the unlocked position, the user may pull the handle <NUM> toward the proximal end of the reaming device <NUM>. In the unlocked position, the tooth <NUM> is disposed apart from the notches <NUM>. As such, the user may pivot the bearing <NUM> about the axis <NUM> to adjust the angle <NUM> between the drive axis <NUM> and the reaming axis <NUM>. After pivoting the bearing <NUM>, the locking mechanism <NUM> may be moved to the locked position.

In some embodiments, the locking mechanism <NUM> includes a biasing element that biases the locking mechanism <NUM> toward the locked position. The biasing element may be a compression spring <NUM> (see <FIG>) that is carried within the frame <NUM>. When the handle <NUM> is pulled to move the locking mechanism <NUM> to the unlocked position, the spring <NUM> is compressed between the frame <NUM> and an enlarged diameter section <NUM> of the rod <NUM>. As such, the user may release the handle <NUM> to permit the spring <NUM> to return the locking mechanism <NUM> to the locked position. Specifically, the spring <NUM> displaces the rod <NUM> to cause the tooth <NUM> to engage one of the notches <NUM>.

<FIG> illustrate an exemplary reaming device <NUM>' similar to the reaming device <NUM> discussed above except as described differently below. Accordingly, numerals used to identify features of the reaming device <NUM> include an apostrophe (') to identify like features of the reaming device <NUM>'. The reaming device <NUM>' includes a reaming head <NUM>' that rotates about a reaming axis <NUM>' (see <FIG>). The reaming axis <NUM>' intersects with and is non-parallel to the drive axis <NUM>' of a drive shaft <NUM>' (see <FIG>). The angle between the reaming axis <NUM>' and the drive axis <NUM>' may be selectively adjusted to enable the user to reduce the removal of bone that does not need to be removed, e.g., to only remove the portions of the bone that need to be removed to insert any of the glenoid components described herein.

<FIG> shows that the reaming head <NUM>' can include a base <NUM>' that connects to the bearing <NUM>'. <FIG> shows that the base <NUM>' has a reaming surface <NUM>' that can remove bone. The reaming surface <NUM>' can include one or more reaming elements <NUM>', each of which includes a reaming edge or surface <NUM>'. Each reaming element <NUM>' can share an edge with another reaming element <NUM>'. For example, the reaming surface <NUM>' can include a number of adjacent rows of reaming elements <NUM>'. When the reaming head <NUM>' rotates, the reaming edges <NUM>' may engage and prepare bone (that is, shape the bone) for subsequently receiving a glenoid component, such as one of the glenoid components <NUM>, <NUM>, or <NUM> described above. In some embodiments, each of the reaming elements <NUM>' can be disposed along an outwardly oriented surface (for example, an arcuate or convex shape) such that the reaming head <NUM>' forms a concave surface in the bone for subsequently receiving the glenoid component.

The reaming head <NUM>' is rotatably driven by the drive shaft <NUM> through a coupling mechanism <NUM>', e.g., a pivot coupling (see <FIG>). The coupling mechanism <NUM>' facilitates rotation of the drive shaft <NUM>' and the reaming head <NUM>' about non-parallel axes (that is, the drive axis <NUM>' and the reaming axis <NUM>').

<FIG> illustrates an exemplary reaming device <NUM> according to embodiments. The reaming device <NUM> may be generally similar to the reaming device <NUM> described above. That is, the reaming device <NUM> includes a reaming head <NUM> that rotates about a reaming axis <NUM>. The reaming axis <NUM> intersects with and is non-parallel to the drive axis <NUM> of a drive shaft (not shown). However, a bearing <NUM> that rotatably mounts the reaming head <NUM> is fixedly connected to a remainder of the device frame <NUM>. For example, the bearing <NUM> may be monolithically formed (for example, formed from or as a single piece of material) with the remainder of the frame <NUM>.

<FIG> illustrate an exemplary method for coupling a glenoid component, such as one of the glenoid components <NUM>, <NUM>, or <NUM> described above, to a scapula of a subject according to embodiments. At block <NUM>, one or more anchor-receiving holes <NUM> are formed in the scapula <NUM> of the subject (see <FIG>). At block <NUM>, a guide pin <NUM> is inserted into one of the anchor-receiving holes <NUM>. At block <NUM>, a first concave surface <NUM> is formed in the scapula <NUM> of the subject. In some embodiments, the surface <NUM> may be formed by using a reaming device that has parallel drive and reaming axes (e.g., having a reaming axis in a direction similar to <FIG>). In some embodiments, the surface <NUM> may be formed by using the reaming device <NUM> described above. The reaming head <NUM> may be oriented at a relatively shallow angle (for example, <NUM> degrees). In some embodiments, the surface <NUM> may be formed at a portion of the glenoid that has experienced little to no erosion, such as an anterior portion, a supero-anterior portion, or an infero-anterior portion.

At block <NUM>, a second concave surface <NUM> is formed in the scapula <NUM> of the subject (see <FIG>). In some embodiments, the surface <NUM> may be formed by using one of the reaming devices <NUM> or <NUM> described above. In some embodiments, the reaming head <NUM> may be oriented at a relatively steep angle (for example, <NUM> degrees). In some embodiments, the second concave surface <NUM> may be formed at a portion of the glenoid that has experienced a significant amount of erosion, such as a posterior portion, a supero-posterior portion, or an infero-posterior portion.

At block <NUM>, the guide pin <NUM> is removed from the scapula <NUM>. At block <NUM>, a glenoid component <NUM> is connected to the scapula <NUM> (see <FIG>). If the glenoid component <NUM> is, for example, the glenoid component <NUM> described above, the base surface portion <NUM> may face the first concave surface <NUM> and the augmented surface portion <NUM> may face the second concave surface <NUM>.

The glenoid components, reaming instruments, and methods described above may be subjected to various other modifications. For example, in some embodiments the glenoid components described above may have an offset center as described in <CIT>. In some embodiments, the center of the glenoid-facing surface is offset from an axis of symmetry of the articulation surface. In some embodiments, the interface between the base surface portion and the augmented surface portion is offset from the barycentre of the articulation surface.

Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims.

As used herein, the relative terms "proximal" and "distal" when describing the reaming device shall be defined from the perspective of the reaming device. Thus, proximal refers to the direction of the drive coupling of the reaming device and distal refers to the direction of the reaming head.

Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.

It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment.

Claim 1:
A device (<NUM>; <NUM>') for removing bone from a glenoid of a subject, the device comprising:
a frame (<NUM>; <NUM>') adapted to be manipulated by a user;
a reaming head (<NUM>; <NUM>') comprising at least one reaming edge (<NUM>; <NUM>') adapted to engage and shape the glenoid; and
a drive shaft (<NUM>; <NUM>') rotatably supported by and extending through the frame and having a distal end which is coupled with the reaming head and which is at least partially disposed within the reaming head (<NUM>; <NUM>'), the drive shaft being rotatable about a drive shaft axis (<NUM>; <NUM>') at the distal end,
wherein the reaming head is adapted to be rotatably driven about a reaming axis (<NUM>; <NUM>') by the drive shaft, the reaming axis being non-parallel to the drive shaft axis at the distal end,
and wherein the reaming head (<NUM>; <NUM>') is also adapted to be selectively adjusted between two or more orientations to respectively form different surfaces on the glenoid at respective portions of the glenoid that have experienced different amounts of bone erosion.