Patent Description:
The present disclosure generally relates to orthopedic hardware, and in particular to plates and screws for fixation of orthopedic hardware relative to the bone of a patient.

In many orthopedic surgeries, various types of hardware may be affixed to a bone of a patient. For instance, orthopedic plates may be used for fixation of bones that have been fractured. A variety of plate types may be provided for use in different contexts. In certain instances, a plate type may be particular to a given anatomical use and/or plate function. In any regard, most often such plates are affixed to the bone of a patient using surgical fasteners such as bone screws.

In some approaches to affixing an orthopedic plate to a bone, it may be desirable to provide flexibility in relation to the angle at which the fastener or screw used to secure the plate to the bone is disposed relative to the plate. For example, it may be desirable to allow for screws to be inserted at various different angles in relation to a plate for different plate applications. However, previously contemplated fasteners and fastener systems include drawbacks that limit the applicability and/or effectiveness of such systems when providing flexibility in relation to the angle at which a screw is advanced relative to a plate for securing a plate to a bone of a patient.

In this regard, a number of systems have been proposed to allow for a screw to be inserted at variable different angles relative to the plate. In such contexts, it may be desirable to provide locking screws that include head portions that are secured to the plate upon insertion of the screw into the bone. As will be seen in the discussion below, provision of a locking screw system that is efficient to use, allows for variable angulation of the screw relative to the plate, and provides for good patient outcomes has yet to be adequately provided.

Some proposed systems include multiple, separately provided pieces that must be manipulated and arranged by the surgeon prior to or at the time of screw insertion. In this regard, the surgeon is required to manipulate a number of parts in relation to screw insertion, which may be particularly difficult when screw insertion is provided in awkward positions relative to the anatomy of the patient. Moreover, the potential for loss of one or more of these parts exists, which may increase foreign body exposure in the surgical site.

In other proposed approaches, the plate through which the screw passes during insertion may comprise a relatively softer material than the screw. In this regard, the screw head is provided with threads that cut into the plate to tap threads as the screw is advanced relative to the plate, thus locking the screw to the plate. That is, the screw may provide self-tapping of the relatively softer material to engage the plate to lock the screw to the plate. However, in this approach, the potential for metal shavings to be produced as the screw head self-taps to the plate. While efforts may be undertaken to remove such metal shavings, any remaining shavings may remain that may result in soft tissue damage. Moreover, after insertion (e.g., during the healing process), this approach may result in cold fusion to occur between the screw head and the plate. In turn, when removing the plate, it may be necessary to use alternative techniques for screw removal other than simply unscrewing the screw from the plate and bone. For instance, the screw may be required to be drilled to remove the screw from the plate and a complicated screw removal process may be undertaken.

An example of a bone plate known in the art is disclosed in European patent publication number <CIT>.

In view of the foregoing, improved orthopedic hardware systems are needed that facilitate variability in relation to the angle at which fasteners are advanced relative to a plate to secure the plates to a bone of the patient. Specifically, a persistent need exists in orthopedic systems that allows for a screw to be used to secure a plate to a bone such that the screw may be positioned with variable angulation relative to the plate in a manner that is functional, efficient, safe, and allows screw removal.

Specifically, embodiments described herein facilitate locking a fastener to a plate such that the fastener may be positioned in different relative angles relative to the plate. In turn, a pivot member is provided that facilitates locking interaction between a fastener and a plate. However, unlike previous systems in which a separate component is provided to facilitate such locking interaction, the present disclosure contemplates an efficient, easy to use system in which components are secured so as to provide a traditional workflow during surgery. That is, the pivot member is restrainedly engaged with the plate such that a surgeon need not separately manipulate a third component beyond the plate and fastener.

In at least some of the embodiments described herein, when a fastener has been used for fixation of a plate to a bone, the fastener is locked to the pivot member that is in turn locked to the plate. For instance, the fastener may include threads on a head portion thereof that engage corresponding threads provided on the pivot member. Accordingly, the threaded engagement between the head portion of the fastener and the pivot member may result in locking interaction between the pivot member and the fastener. In addition, the head portion engaging the pivot member may result in radial expansion of the pivot member, which may frictionally engage a sidewall of an aperture in the plate to lock the pivot member with respect to the plate. In this embodiment, the fastener may engage the bone of a patient and the plate so that the plate is not loaded in compression relative to the bone of the patient. In this regard, the resistance to shearing forces may be significantly improved. Specifically, when a locking screw that threadably engages the pivot member is used, the screw may be engaged with shearing forces along an entire length of the screw so as increase the resistance to shearing forces of the screw. In alternative embodiments, conventional screws may be used that load the pivot member and plate in compression for securing the plate relative to the bone of the patient.

In view of the foregoing, the present invention provides an orthopedic plate. The plate includes a plate body extending between an upper surface and a lower surface of the plate body. The plate also features an aperture extending through the plate body from the upper surface to the lower surface along a reference axis. The aperture has a sidewall extending circumferentially about an interior of the aperture. The aperture comprises a non-circular sidewall portion. In addition, the aperture comprises a ramped surface of a flange extending relative to the aperture. The plate includes a pivot member that is retained within the aperture. The pivot member includes an outer surface corresponding to the sidewall of the aperture. The pivot member defines a bore extending along a fastener insertion axis. The bore is configured to accept a fastener along the fastener insertion axis. The pivot member includes a plurality of flats extending about a proximal perimeter of the pivot member and the non-circular sidewall portion includes correspondingly shaped flat portions. The outer surface is engageable by the non-circular sidewall portion to inhibit rotation of the pivot member about the reference axis. The flange engages a distal convex portion of the pivot member. In turn, the pivot member is disposable between a first configuration that allows relative movement between the outer surface and the sidewall and a second configuration in which the outer surface frictionally engages the sidewall to restrict movement of the pivot member relative to the aperture. The pivot member is displaceable relative to the plate body within the aperture when in the first configuration to define an included angle between the reference axis and the insertion axis.

A number of feature refinements and additional features are applicable to the present invention. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature or combination of features of the first aspect.

For instance, the second configuration of the pivot member may include radial expansion of the pivot member to frictionally engage the sidewall with the outer surface. In an embodiment, at least one of the bore or a head portion of the fastener disposed within the bore may include a sloped surface such that the head portion and the bore are engageable upon receipt of the fastener in the bore to cause the radial expansion. That is, the sloped surface of the head portion and/or bore may be disposed such that as the head portion is engaged with the pivot member (e.g., through threadable and/or compressive engagement), the pivot member may radially expand. As such, the pivot member may include an expansion slot that allows for the radial expansion of the pivot member radially relative to the fastener insertion axis. The expansion slot may extend through the pivot member in a direction along the insertion axis. In an embodiment, the slot may extend entirely through the pivot member in a direction along the insertion axis. That is, the pivot member may be split to facilitate radial expansion thereof. In other embodiments, a plurality of expansion slots may be provided that may be spaced about the pivot member. The plurality of expansion slots may extend partially through the pivot member to facilitate radial expansion of at least a portion of the pivot member.

In an embodiment, the pivot member may be a substantially hexagonal member similar to commonly provided nuts. The pivot member may also include chamfers extending between the plurality of flats to facilitate unrestricted pivotal movement of the pivot member relative to the plate in two degrees of freedom. That is, in a traditional hexagonally shaped nut, pivotal movement within the aperture may be restricted due to interference between the flats of the nut and the sidewall. Providing chamfers between the flats of the pivot member may reduce or eliminate such interference, allowing the pivot member to pivot freely within the aperture.

In an embodiment, the plate may facilitate engagement of the fastener and the plate such that the fastener is loaded without compression forces. For instance, the bore may include threads adapted to engage corresponding threads on a head portion of the fastener. In this regard, by threadably engaging the pivot member with the head portion of the fastener, the fastener may be loaded without compression. It has been found that such absence of compression loading of a fastener may allow for greater resistance to shear forces or other forces (e.g., axial forces, tensile forces, bending moments, etc.) acting between the plate and the fastener as the plate is loaded (e.g., as a result of anatomical movement or the like).

In an embodiment, the included angle between the reference axis and the fastener insertion axis may be definable in at least one degree of freedom when the pivot member is in the first configuration. The included angle between the reference axis and the insertion axis may be definable in at least two degrees of freedom. The included angle between the reference axis and the fastener insertion axis is definable at any radial position about the reference axis. The included angle between the reference axis and the insertion axis may be at least about <NUM> degrees. Alternatively, the included angle between the reference axis and the insertion axis may be at least about <NUM> degrees.

The pivot member may be irremovably provided within the aperture. In this regard, the plate body may include extensions adjacent to the upper surface and extending relative to the aperture. The extensions may originally be positioned to allow for passage of the pivot member into the aperture. Thereafter, the extension members may be moved to secure the pivot member in the aperture. That is, the extensions may be displaceable into position to extend relative to the aperture upon receipt of the pivot member into the aperture to secure the pivot member within the aperture. As such, the extensions may extend relative to the aperture to retain the pivot member in the aperture. Such extensions may extend parallel to a surface of the plate or may extend in a direction normal to the surface of the plate. In this regard, the extensions may comprise flanges that extend normal to the surface of a plate to allow the pivot member to be disposed in the aperture, such that the flanges are moved into a parallel position relative to the surface of the plate to secure the pivot member. Alternatively, the extensions may extend parallel to the surface of the plate and define a hole through which the pivot member may be passed through in a collapsed or retracted state. Once through the hole and in the aperture, the pivot member may be expanded such that the extensions maintain the pivot member securely within the aperture.

<FIG> depicts an embodiment of a pivot member <NUM> and a plate <NUM>. The plate <NUM> includes an aperture <NUM> extending between an upper surface <NUM> of the plate <NUM> and a lower surface <NUM> of the plate. The aperture <NUM> is sized so as to receivingly engage the pivot member <NUM>, which is shown in an exploded state in <FIG>. The aperture <NUM> extends along and define a reference axis <NUM>.

With additional reference to <FIG>, the pivot member <NUM> includes a bore <NUM>. The bore <NUM> may, in at least some embodiments, be threaded. In any regard, the bore <NUM> defines a fastener insertion axis <NUM> along which a fastener (not shown in <FIG>) is advanceable relative to the pivot member <NUM>.

The pivot member <NUM> may comprise an expansion slot <NUM>. The expansion slot <NUM> may define a gap or opening of the pivot member <NUM> that extends along the entire pivot member <NUM> in a direction corresponding to (e.g., parallel with) the fastener insertion axis <NUM>. Alternatively, the expansion slot <NUM> may not extend along the entire distance of the pivot member <NUM>. For instance, the expansion slot <NUM> may only extend along a portion of the distance of the pivot member <NUM> in a direction corresponding to the fastener insertion axis <NUM>. Moreover, in an embodiment that the expansion slot <NUM> does not extend entirely along the distance of the pivot member <NUM>, a plurality of expansion slots <NUM> may be provided radially about the pivot member <NUM>. In any regard, the expansion slot <NUM> may facilitated radial expansion of the pivot member <NUM> relative to the fastener insertion axis <NUM>.

In addition, the pivot member <NUM> comprises an outer surface <NUM> that is of a shape corresponding to a sidewall <NUM> of the aperture <NUM>. The sidewall <NUM> extends circumferentially about the aperture <NUM>. In this regard, can be seen in <FIG>, the pivot member <NUM> is alignable with and received in the aperture <NUM>. When the aperture <NUM> receives the pivot member <NUM>, the outer surface <NUM> of the pivot member <NUM> is in conformal adjacent relation to the sidewall <NUM> of the aperture <NUM>. For instance, as shown in <FIG>, the pivot member <NUM> is received in the aperture <NUM> such that the outer surface <NUM> of the pivot member <NUM> is disposed in adjacent relation to the sidewall <NUM> of the aperture <NUM>. With further reference to <FIG>, the conformal corresponding outer surface <NUM> and sidewall <NUM> allows for pivotal movement of the pivot member <NUM> relative to the aperture <NUM>. In turn, the fastener insertion axis <NUM> and the reference axis <NUM> may be disposed to define an included angle θ therebetween.

As may be appreciated, the pivot member <NUM> is capable of pivotal movement relative to the plate <NUM> in at least one degree of freedom to define the included angle θ. In a preferred embodiment, the pivot member <NUM> may be capable of pivotal movement relative to the plate <NUM> in at least two degrees of freedom. In this regard, the included angle θ may be defined at any radial position about the reference axis <NUM>. That is, if considering the possible positions of the fastener insertion axis <NUM> relative to the reference axis <NUM> as defining a field of possible positions, the fastener insertion axis <NUM> may be disposed in any position defining a cone extending along the reference axis <NUM>. In addition, the plate <NUM> may comprise a skirted portion <NUM> that may facilitate acceptance of a fastener within the bore <NUM> when the pivot member <NUM> is disposed at the included angle θ. In this regard, the pivot member <NUM> may be pivotal relative to the plate <NUM> such that the included angle θ is at least <NUM> degrees. In alternate embodiments, the included angle θ may be at least about <NUM> degrees.

With returned reference to <FIG>, prior to insertion of the pivot member <NUM> into the aperture <NUM>, an extension <NUM> may extend from the upper surface <NUM> adjacent to the aperture <NUM>. As shown in a first configuration in <FIG>, the extension <NUM> may be disposed to allow for the pivot member <NUM> to be received in the aperture <NUM>. Upon receipt of the pivot member <NUM> in the aperture <NUM>, the extension <NUM> may be displaced toward the reference axis <NUM> as shown in <FIG>. As can be seen in particular in <FIG>, the extension <NUM>, when displaced after the pivot member <NUM> is received in the aperture <NUM> may assist in retaining the pivot member <NUM> within the aperture <NUM>. That is, when the pivot member <NUM> is pivoted relative to the aperture <NUM>, the extension <NUM> may comprise a portion of the conformal, adjacent sidewall <NUM> of the aperture <NUM> to retain the pivot member <NUM> within the aperture.

<FIG> depicts an alternate embodiment of a plate <NUM> having an extension <NUM> that extends parallel to the upper surface <NUM>. In this regard, the extensions <NUM> may define a hole <NUM> that has a smaller cross dimension than the aperture <NUM>. In this regard, the pivot member <NUM> may be retracted or collapsed to allow for passage through the hole <NUM>. Once disposed in the aperture <NUM>, the pivot member <NUM> may be expanded such that the extension member <NUM> extending parallel to the upper surface <NUM> may restrict the pivot member <NUM> from being removed from the aperture <NUM>.

In this regard, the pivot member <NUM> is disposed in and retained by the aperture <NUM>. This arrangement may be established prior to the use of the plate <NUM> in a surgical operation. Because the pivot member <NUM> is retained within the aperture <NUM>, a surgeon or other user during surgery may not be required to manipulate the pivot member <NUM> to dispose it relative to a fastener and/or the plate <NUM>. In turn, the plate <NUM> may be provided as a unitary component to the surgeon for use in affixing the plate <NUM> to a bone of a patient without having the added complexity of alignment and engagement of the pivot member <NUM> relative to the plate <NUM>.

The outer surface <NUM> of the pivot member <NUM> is noncircular. In corresponding relation, the sidewall <NUM> of the aperture <NUM> includes at least a portion that is non-circular. In this regard, the outer surface <NUM> and the sidewall <NUM> interface to restrict rotation of the pivot member <NUM> relative to the aperture <NUM>. For instance, the pivot member <NUM> includes a plurality of flats <NUM> that correspond to flat portions <NUM> of the aperture <NUM> as can be seen in <FIG>. Chamfers <NUM> may be provided between the flats <NUM> as can best be seen in <FIG>. The chamfers <NUM> may assist in facilitating pivoting of the pivot member <NUM> relative to the aperture <NUM> (e.g., to provide two degrees of freedom of movement of the pivot member <NUM> relative to the plate <NUM> as described above).

In addition, the pivot member <NUM> includes a convex portion <NUM>. The convex portion <NUM> is in conformal adjacent relation to a ramped surface <NUM>. The ramped surface <NUM> extend along a flange <NUM> that extends from the sidewall <NUM> toward the reference axis <NUM>. In this regard, the flange <NUM> and ramped surface <NUM> comprise a bowled portion that receives the convex portion <NUM> of the pivot member <NUM> when the pivot member <NUM> is disposed in the aperture <NUM>.

With further reference to <FIG>, an embodiment of a fastener <NUM> is shown relative to the pivot member <NUM> and plate <NUM>. The pivot member <NUM>, plate <NUM>, and fastener <NUM> may comprise an orthopedic implant system <NUM>. The fastener <NUM> may comprise a screw such as a surgical screw or the like. The fastener <NUM> may comprise a self-tapping screw, or include any other features common to surgical screws. The fastener <NUM> may comprise an elongate portion <NUM> at a distal portion of the fastener <NUM> and a head portion <NUM> at a proximal portion of the fastener <NUM>. The elongate portion <NUM> may comprise threads <NUM>. In this regard, the fastener <NUM> may be in threaded engagement with corresponding threads disposed about the bore <NUM> of the pivot member <NUM>. In addition, the threads <NUM> of the fastener <NUM> may be used to advance the fastener <NUM> relative to a bone of a patient for securing the fastener <NUM> to the bone after having passed through the pivot member <NUM> and plate <NUM>.

The head portion <NUM> may also comprise threads <NUM>. The threads <NUM> may be the same pitch as the threads <NUM> of the elongate portion <NUM>. In addition, the threads <NUM> on the head portion <NUM> may comprise a double thread. In this regard, two threads of the same pitch may be provided on the head portion <NUM>. In this regard, the pitch of the threads <NUM> of the elongate portion <NUM> may be the same as the pitch of the threads <NUM> of the head portion <NUM> with the head portion <NUM> featuring a double thread. Both threads <NUM> and <NUM> may engage with the threads of the bore <NUM>, or threads <NUM> on the head portion <NUM> alone may engage the threads of the bore <NUM>. In this latter regard, the threads <NUM> on the elongate portion <NUM> may be provided to engage the bone of a patient, yet may not contact the pivot member <NUM> as the fastener <NUM> is advanced relative thereto. The head portion <NUM> may have a sloped surface that defines a profile such that the diameter of the head increases toward the proximal end of the fastener <NUM>. For instance, the head portion <NUM> may be frustoconical. In any regard, the pitch diameter of the fastener <NUM> may increase toward the proximal end of the fastener <NUM>.

In turn, the interaction of the fastener <NUM> may result in locking of the pivot member <NUM> relative to the plate <NUM>. Specifically, as described above, the pivot member <NUM> may be expandable radially in relation to the fastener insertion axis <NUM>. For instance, the interaction of the fastener <NUM> (e.g., the head portion <NUM> thereof) as it is advanced relative to the pivot member <NUM> may cause the radial expansion of the pivot member <NUM>. In turn, the outer surface <NUM> of the pivot member <NUM> may frictionally engage the sidewall <NUM> of the aperture <NUM>. The frictional engagement of the outer surface <NUM> with the sidewall <NUM> may at least limit, and in some instances prevent, movement of the pivot member <NUM> relative to the plate <NUM>.

In some embodiments, the threaded engagement of the threads <NUM> of the head portion <NUM> of the fastener <NUM> may act on the bore <NUM> to radially expand the pivot member <NUM> relative to the aperture <NUM> to from a first configuration as shown in <FIG> to a second configuration as shown in <FIG> and <FIG>. In the first configuration, the outer surface <NUM> is moveable relative to the conformal adjacent sidewall <NUM> of the aperture <NUM>. However, in the second configuration, the outer surface <NUM> of the pivot member <NUM> contactingly engages the sidewall <NUM>.

Upon advancement of the fastener <NUM> relative to the pivot member <NUM>, the head portion <NUM> may threadingly engage the bore <NUM> of the pivot member <NUM>. As the head portion <NUM> may have an increased diameter as compared to the elongate portion <NUM> (e.g., including potentially including a frustoconically shaped portion with increasing diameter along the head portion <NUM> in a proximal direction), the engagement of the head portion <NUM> with the pivot member <NUM> expands the pivot member <NUM> radially relative to the fastener insertion axis <NUM> to the second configuration as shown in <FIG> and <FIG>. That is, the second configuration of the pivot member <NUM> may be at a greater radial expansion than that of the first configuration.

In the second configuration, the outer surface <NUM> of the pivot member <NUM> engages the sidewall <NUM> of the aperture <NUM> to restrict movement of the pivot member <NUM> relative to the plate <NUM>. In this second configuration, the movement of the pivot member <NUM> relative to the plate <NUM> is fully restricted such that forces imparted by a surgeon, forces resulting from installation of the plate <NUM> to the bone of a patient, or forces that are imparted to the pivot member <NUM>, plate <NUM>, and fastener <NUM> once installed do not result in movement of the pivot member <NUM> relative to the plate <NUM>. In an embodiment, the head portion <NUM> threadably engages the bore <NUM> when the head portion <NUM> is advanced to the pivot member <NUM>. In this regard, the fastener <NUM> may be rigidly engaged with the pivot member <NUM> that is in turn frictionally engaged with the aperture <NUM>.

In other embodiments, the conical or frustoconical shape of a head portion <NUM> without threads may also be used. In this embodiment, the advancement of the fastener <NUM> relative to the bone of a patient causes compressive forces to act on the pivot member <NUM> such that the frustoconical head portion <NUM> still results in radial expansion of the pivot member <NUM> to frictionally engage the aperture <NUM> as illustrated in <FIG>. Accordingly, the fastener <NUM> may be lockingly engageable with the pivot member <NUM> by threaded interaction therebetween such that the fastener <NUM> is in turn loaded without compression forces acting between the fastener <NUM> and the plate <NUM>. In contrast, the fastener <NUM> may lacking locking threads to lock the fastener <NUM> to the pivot member <NUM> such that the fastener <NUM> may be loaded in compression to lock the pivot member <NUM> relative to the plate <NUM>.

<FIG> depicts a comparative example of an orthopedic implant system <NUM>. The system <NUM> includes a plate <NUM>, a pivot member <NUM>, and a fastener <NUM>. Unlike the system <NUM> described above in which the pivot member <NUM> is retainedly engaged with the plate <NUM> within the aperture <NUM>, system <NUM> may include a fastener <NUM> that retains the pivot member <NUM> therewith. In this regard, the pivot member <NUM> may pivot relative to the fastener <NUM> and may provide angulation of the fastener <NUM> while still allowing the pivot member <NUM> to be lockingly engaged with the plate <NUM> as will be described in greater detail below.

The plate <NUM> includes an aperture <NUM>. As shown in <FIG>, the fastener <NUM> includes the pivot member <NUM> in retained engaged relation to a head portion <NUM> of the fastener <NUM>. In this regard, the fastener <NUM> may pass through the aperture <NUM> such that the pivot member <NUM> engages the plate <NUM>. When engaged with the plate <NUM>, the fastener <NUM> and pivot member <NUM> may be lockingly engaged to restrict or prevent movement between the plate <NUM>, pivot member <NUM> and fastener <NUM>.

With additional reference to <FIG>, the pivot member <NUM> may comprise a bore <NUM>. The bore <NUM> may comprise a non-circular sidewall <NUM> that at least partially defines the bore <NUM>. The head portion <NUM> may have an outer surface <NUM> that is correspondingly non-circular relative to the sidewall <NUM>. In this regard, upon rotation of the fastener <NUM>, the pivot member <NUM> may undergo corresponding rotational movement by interaction of the sidewall <NUM> and the outer surface <NUM>. As can best be seen in <FIG>, the outer surface <NUM> of the head portion <NUM> may be in conformal adjacent relation to the sidewall <NUM> of the bore <NUM>. The outer surface <NUM> and the sidewall <NUM> may be curved to allow pivotal movement between the fastener <NUM> and the pivot member <NUM>. Specifically, the pivot member <NUM> may define a reference axis <NUM> about which the bore <NUM> extends. The fastener <NUM> may extend along a fastener insertion axis <NUM>. Accordingly, the pivotal movement between the fastener <NUM> and the pivot member <NUM> may define an included angle θ therebetween.

The included angle θ in the system <NUM> may include any of the characteristics described above in relation to system <NUM>. That is, the included angle θ may be defined at any radial position about the reference axis <NUM>. In addition, the included angle θ may be at least about <NUM> degrees in an embodiment or even at least about <NUM> degrees.

With reference to <FIG>, the fastener <NUM> may be advanced through the aperture <NUM> of the plate <NUM>. For instance, while not shown in <FIG>, the elongate portion <NUM> of the fastener <NUM> may be advanced into the bone of a patient. As the fastener <NUM> is advanced relative to the plate <NUM>, the head portion <NUM> may be advanced toward the plate <NUM> such that the pivot member <NUM> may be disposed within the aperture <NUM>. <FIG> shows the fastener <NUM> is in position such that a portion of the pivot member <NUM> is disposed with in the aperture <NUM> of the plate <NUM>.

As can best be seen in <FIG>, the pivot member <NUM> comprises a first locking feature on a distal portion thereof. The aperture <NUM> comprises a second locking feature on a proximal-facing portion of the aperture <NUM>. The first locking feature on the pivot member <NUM> may correspond to the second locking feature of the aperture <NUM> so that the first locking feature and the second locking feature are engageable for locking interaction therebetween.

Specifically, the first locking feature of the pivot member <NUM> comprises a plurality of ramped surfaces <NUM>. The second locking feature of the aperture <NUM> comprises a plurality of teeth <NUM>. As the fastener <NUM> is advanced relative to the bone of a patient, the fastener <NUM> also moves distally relative to the plate <NUM>. Because the pivot member <NUM> is retained by the head portion <NUM> of the fastener <NUM>, the distal movement of the fastener <NUM> brings the ramped surfaces <NUM> in contact with the teeth <NUM>. As the fastener <NUM> is rotated, the ramped surfaces <NUM> travel along the teeth <NUM> in a ratcheting action as the fastener <NUM> is advanced. Upon continued advancement of the fastener <NUM>, the teeth <NUM> will interlockingly engage the ramped surfaces <NUM> as shown in <FIG>. The interlocking engagement between the ramped surfaces <NUM> and the teeth <NUM> may restrict rotation of the fastener <NUM> in a direction opposite the direction in which the fastener <NUM> is rotated as it is advanced.

In this regard, as the fastener <NUM> is advanced relative to the plate <NUM>, the pivot member <NUM> is clampingly engaged in the aperture <NUM> by the head portion <NUM> of the fastener <NUM>. Moreover, the interlocking engagement of the ramped surfaces <NUM> and the teeth <NUM> restrict rotation of the fastener <NUM> tending to withdraw the fastener <NUM> proximally. As such, the fastener <NUM> remains clampingly engaged with the plate <NUM>. Moreover, the compressive forces acting between the fastener head <NUM> and the pivot member <NUM> create frictional engagement between the outer surface <NUM> of the head portion <NUM> and the sidewall <NUM> of the bore <NUM>. In turn, the included angle θ defined between the fastener insertion axis <NUM> and the reference axis <NUM> is maintained as further pivotal movement between the head portion <NUM> and the pivot member <NUM> is restricted or prevented based on the frictional interaction between the sidewall <NUM> and the outer surface <NUM>. By restricted from pivotal movement, it is meant that the forces experienced during bone healing or movement by the patient will not cause such pivotal movement. That is, application of a large force (e.g., by a surgeon with assistance of a tool or the like) may be able to cause such pivotal movement to remove the hardware during a surgical procedure.

With further reference to <FIG>, another comparative example <NUM> of an orthopedic implant system <NUM> is shown. The system <NUM> comprises a plate <NUM>, a pivot member <NUM>, and a fastener <NUM>. Like in the embodiment of the orthopedic implant system <NUM> described above, the pivot member <NUM> may be retainedly engaged with a head portion <NUM> of the fastener <NUM>. In this regard, the pivot member <NUM> may pivot relative to the fastener <NUM>. The pivot member <NUM> may define a bore <NUM> that may extend along a reference axis. The fastener <NUM> may extend along a fastener insertion axis. In turn, the pivotal movement of the pivot member <NUM> relative to the fastener <NUM> may define an included angle between the reference axis and the fastener insertion axis as described above in relation to the system <NUM>.

Specifically, the head portion <NUM> may comprise an outer surface <NUM>. Additionally, the bore <NUM> may comprise a sidewall <NUM>. The outer surface <NUM> may be disposed in conforming adjacent relation to the sidewall <NUM>. In the comparative example of the system <NUM>, the outer surface <NUM> may be arcuate both circumferentially about the fastener insertion axis and at least partially arcuate along the fastener insertion axis. That is, the outer surface <NUM> may be at least partially spherical. In turn, the sidewall <NUM> may be conformingly shaped relative to the outer surface <NUM> such that the sidewall <NUM> may be at least partially spherical as well. In turn, the pivot member <NUM> may pivot relative to the head portion <NUM>.

In turn, the fastener <NUM> may be advanced relative to the plate <NUM> such that the pivot member <NUM> is disposed within an aperture <NUM> of the plate <NUM> that extends from an upper surface <NUM> to a lower surface <NUM> of the plate <NUM>. As can best be seen in <FIG>, when the pivot member <NUM> is disposed in the aperture <NUM>, a first locking feature of the pivot member <NUM> may be disposed relative to a second locking feature of the plate <NUM>. Specifically, the pivot member <NUM> may comprise a ramped surface <NUM>. This is more clearly seen in <FIG>, which depicts the position of the pivot member <NUM> in <FIG> without the plate <NUM> shown for clarity.

As can be appreciated, a plurality of ramped surfaces <NUM> may also be provided without limitation. The aperture <NUM> comprises one or more shoulders <NUM>. As such, when the fastener <NUM> is advanced relative to the plate <NUM> (e.g., by advancing a threaded elongate portion <NUM> of the fastener <NUM> into a bone of a patient), the pivot member <NUM> that is retained at the head portion <NUM> may be advanced relative to the aperture <NUM>. The advancement of the fastener <NUM> may include rotation in a first direction (e.g., clockwise). When the fastener <NUM> is fully advanced, the pivot member <NUM> may be disposed such that the ramped surfaces <NUM> are not contacting the shoulder <NUM> as shown in <FIG>.

In turn, rotation of the pivot member <NUM> in a second direction opposite the first direction (e.g., counterclockwise) may cause the ramped surfaces <NUM> to engage the shoulder <NUM> as shown in <FIG> depicts the position of the pivot member <NUM> in the absence of the plate <NUM> for clarity. Specifically, the ramped surfaces <NUM> may slidingly engage the shoulder <NUM>, which may be inclined in corresponding relation to the ramped surfaces <NUM>. IN turn, the ramped surfaces <NUM> may slidingly engage to ride up the shoulder <NUM>. This may cause the pivot member <NUM> to be urged away from the plate <NUM>. As the fastener <NUM> may be captured in the bone of the patient, the urging of the pivot member <NUM> away from the plate <NUM> may clampingly engage the plate <NUM> with the bone of the patient. Moreover, the pivot member <NUM> may impart a clamping force on the head portion <NUM> of the fastener <NUM>. The clamping force acting between the pivot member <NUM> and the fastener <NUM> may result in frictional engagement of the sidewall <NUM> of the aperture <NUM> with the outer surface <NUM> of the head portion <NUM>. This frictional engagement may maintain the position of the fastener <NUM> relative to the pivot member <NUM>.

Additionally, the shoulder <NUM> may include a lip <NUM>. The lip <NUM> may be disposed such that a trialing edge <NUM> of the ramped surface <NUM> may pass over the lip <NUM>. In this regard, the ramped surface <NUM> may be disposed relative to the lip <NUM> such that rotation of the pivot member <NUM> in the first direction (i.e., tending to cause the pivot member to unclamp the plate <NUM> and fastener <NUM>) may be restricted by the lip <NUM>. Accordingly, the pivot member <NUM> may be restricted, and in some instances prevented, from relative movement with respect to the fastener <NUM>. As stated above, restricted relative movement may include prevention of such movement during bone healing or normal patient activities, but could be overcome by the force applied by a surgeon using a tool to remove the fastener <NUM>.

With further reference to <FIG>, the rotation of the pivot member <NUM> in the second direction may be induced by interaction with a tool <NUM>. For instance, the tool <NUM> may comprise projections <NUM> that correspondingly engage slots <NUM> provided on the pivot member <NUM>. In this regard, the tool <NUM> may be engaged with the pivot member <NUM> such that the projections <NUM> engage the slots <NUM>. In turn, the tool <NUM> may be used to rotate the pivot member <NUM> to engage the ramped surfaces <NUM> with the shoulder <NUM> to impart the clamping forces as described above.

With further reference to <FIG>, another comparative example of an orthopedic plate system is depicted. The system depicted in <FIG> may include a plate <NUM> having a bore <NUM> extending from a top surface <NUM> to a bottom surface <NUM> of the plate <NUM>. A fastener <NUM> may be provided that may pass through the bore <NUM> to engage the bone of the patient for fixation of the plate <NUM> relative to the bone of the patient. A pivot member <NUM> may be secured relative to a head portion <NUM> of the fastener <NUM>. As will be described in greater detail below, the pivot member <NUM> may be disposed between a head portion <NUM> and a ledge <NUM> that extends radially from the fastener <NUM>. In any regard, as the fastener <NUM> is advanced relative to the bone of the patient, the pivot member <NUM> may become disposed within the aperture <NUM> of the plate <NUM>. Thereafter, the pivot member <NUM> may be selectively radially expanded to lockingly engage the plate <NUM>.

The fastener <NUM> may include an elongate portion <NUM>. The elongate portion <NUM> may comprise threads <NUM> that are engageable with the bone of the patient to advance the fastener <NUM> relative to the bone of the patient. The fastener <NUM> may include the head portion <NUM> which is disposed near a proximal end portion <NUM> of the fastener <NUM>. The head portion <NUM> may be threadably engaged with the proximal end portion <NUM> of the fastener <NUM>. Accordingly, the head portion <NUM> may be advanced distally or retracted proximally by corresponding respective rotation of the head portion <NUM> relative to the proximal end portion <NUM> of the fastener <NUM>. The ledge <NUM> briefly described above may extend radially relative to a fastener insertion axis <NUM> that generally extends along the elongate portion <NUM>. The ledge <NUM> may be extend about the fastener <NUM> circumferentially such that the ledge <NUM> defines a stop such that the pivot member <NUM> may not be advanced distally relative to the ledge <NUM>.

As shown in <FIG>, the pivot member <NUM> may be arranged such that the pivot member <NUM> is disposed between the head portion <NUM> and the ledge <NUM> to retainedly engaged the pivot member <NUM> therebetween. As may be appreciated, the pivot member <NUM> may be relatively easily disposed between the head portion <NUM> and the ledge <NUM> by removing the head portion <NUM> from the proximal end portion <NUM> of the fastener <NUM>. Thereafter, the pivot member <NUM> may be disposed about the fastener <NUM> such that the fastener <NUM> extends relative to a bore <NUM> defined by the pivot member <NUM>. The head portion <NUM> may be reengaged with the proximal end portion <NUM> by way of the threadable engagement provided therebetween. The engagement of the pivot member <NUM> relative to the fastener member <NUM> may be performed prior to a surgeon utilizing the fastener <NUM> to secure the plate <NUM> relative to the patient. As such, the fastener <NUM> with the pivot member <NUM> disposed relative thereto may be provided for use by a surgeon as an integral unit or preconfigured subassembly such that the utilization of the fastener <NUM> and pivot member <NUM> are efficient to the surgeon.

The proximal end portion <NUM> may include a first tool receiving portion <NUM>. For instance, the first tool receiving portion <NUM> may comprise a hexagonally shaped recess that may accept a correspondingly hexagonally shaped tool portion. Other configurations of the first tool receiving portion <NUM> may be provided that allow for controllable rotation of the elongate portion <NUM> of the fastener <NUM>.

The head portion <NUM> may include one or more second tool receiving portions <NUM>. For instance, as shown in <FIG> the second tool receiving portions <NUM> may include cylindrical recesses provided in the head portion <NUM>. The second tool receiving portions <NUM> may be distributed radially about the proximal portion of the head portion <NUM> such that the second tool receiving portions <NUM> are accessible from the proximal portion of the fastener <NUM>. It may be appreciated that other configurations of the second tool receiving portions <NUM> may be provided. Specifically, any configuration that allows for engagement by a tool for controlled rotation of the head portion <NUM> may be provided without limitation.

In this regard, the first tool receiving portion <NUM> may be engaged by a tool portion that may in turn impart rotation of the fastener <NUM> about the fastener insertion axis <NUM>. This may in turn caused threads <NUM> to engage the bone of the patient and be advanced relative thereto. During the rotational advancement of the fastener <NUM> the second tool receiving portions <NUM> may be engaged and correspondingly rotated to prevent relative rotation between the head portion <NUM> and the proximal end portion <NUM> of the fastener <NUM>. Alternatively, the first tool receiving portion <NUM> may be engaged alone to advance the fastener <NUM>. In this regard, the head portion <NUM> may correspondingly rotate with the proximal end portion <NUM> absent engagement with the second tool receiving portions <NUM>.

In any regard, as the fastener <NUM> is advanced relative to the plate <NUM>, the pivot member <NUM> that may be restrainedly engaged between the head portion <NUM> and the ledge <NUM> may also be advanced relative to the plate <NUM>. Specifically, the pivot member <NUM> may be advanced so that it is disposed within the aperture <NUM> of the plate <NUM>. The aperture <NUM> of the plate <NUM> may include a neck portion <NUM>. The pivot member <NUM> may also include an expansion slot <NUM> that allows for radial expansion and contraction of the pivot member <NUM> relative to the fastener insertion axis <NUM>. In this regard, as the fastener <NUM> is advanced relative to the plate <NUM>, the pivot member <NUM> may engage the neck portion <NUM>. Upon further advancement of the fastener <NUM>, the pivot member <NUM> may be radially compressed such that the pivot member <NUM> a pass by the neck portion <NUM> into a pocket <NUM> of the aperture <NUM>. The pocket <NUM> may be a spheroid shaped portion comprising a sidewall <NUM> of the aperture <NUM>. This configuration in which the pivot member <NUM> is disposed in the pocket <NUM> of the aperture <NUM> shown in <FIG>.

The head portion <NUM> may be engaged at the second tool receiving portion <NUM> to impart rotation of the head portion <NUM> relative to the proximal end portion <NUM> to advance the head portion <NUM> distally relative to the proximal end portion <NUM>. As can best be appreciated collectively in <FIG> and <FIG>, the distal advancement of the head portion <NUM> may cause a ramped surface <NUM> of the head portion <NUM> to engage the bore <NUM> of the pivot member <NUM>. In turn, the distal advancement of the head portion <NUM> may cause the ramped surface <NUM> cause the radial expansion of the pivot member <NUM> such that an outer surface <NUM> of the pivot member <NUM> frictionally engages the sidewall <NUM> of the pocket <NUM>. Accordingly, the pivot member <NUM> may be lockingly engaged relative to the plate <NUM> by way of advancement of the head portion <NUM> relative to the proximal end portion <NUM> so as to urge the pivot member <NUM> and radial expansion against the sidewall <NUM>.

As in the previous embodiments, the fastener <NUM> may be inserted relative to the plate such that an angle θ is included between the fastener insertion axis <NUM> and the reference axis <NUM>. Upon advancement of the head portion <NUM> distally relative to the proximal end portion <NUM> of the fastener <NUM>, the fastener may be lockingly engaged relative to the plate at the angle θ. As in the foregoing embodiments, the angle θ may be at least about <NUM>°.

Claim 1:
An orthopedic plate (<NUM>), comprising:
a plate body extending between an upper surface (<NUM>) and a lower surface (<NUM>) of the plate body, an aperture (<NUM>) extending through the plate body, and a pivot member (<NUM>) retained within the aperture (<NUM>);
wherein the aperture (<NUM>) extends through the plate body from the upper surface (<NUM>) to the lower surface (<NUM>) along a reference axis (<NUM>), the aperture (<NUM>) having a sidewall (<NUM>) extending circumferentially about an interior of the aperture (<NUM>), wherein the aperture (<NUM>) comprises a non-circular sidewall portion, wherein the aperture (<NUM>) comprises a ramped surface (<NUM>) of a flange (<NUM>) extending relative to the aperture (<NUM>);
the pivot member (<NUM>) retained within the aperture (<NUM>) comprises an outer surface (<NUM>) corresponding to the sidewall (<NUM>), the pivot member (<NUM>) defining a bore (<NUM>) extending along a fastener insertion axis (<NUM>), wherein the bore (<NUM>) is configured to accept a fastener (<NUM>) along the fastener insertion axis (<NUM>), wherein the pivot member (<NUM>) comprises a plurality of flats (<NUM>) extending about a proximal perimeter of the pivot member (<NUM>) and the non-circular sidewall portion includes correspondingly shaped flat portions (<NUM>) and the outer surface (<NUM>) is engageable by the non-circular sidewall portion to inhibit rotation of the pivot member (<NUM>) about the reference axis (<NUM>), wherein the flange (<NUM>) engages a distal convex portion (<NUM>) of the pivot member (<NUM>);
wherein the pivot member (<NUM>) is disposable between a first configuration that allows relative movement between the outer surface (<NUM>) and the sidewall (<NUM>) and a second configuration in which the outer surface (<NUM>) frictionally engages the sidewall (<NUM>) to restrict movement of the pivot member (<NUM>) relative to the aperture (<NUM>); and
wherein the pivot member (<NUM>) is displaceable relative to the plate body within the aperture (<NUM>) when in the first configuration to define an included angle (θ) between the reference axis (<NUM>) and the fastener insertion axis (<NUM>),