Patent Description:
The field of the present disclosure generally relates to securing bones together. More particularly, the field of the present disclosure relates to an apparatus for fusing and compressing bones of the human body.

A fusion bone plate implant may be utilized in conjunction with one or more fasteners so as to generate compression and stability at a bone interface. An implant coupled with fasteners generally serves to stabilize bones, or bone parts, relative to one another so as to promote bone fusion. In many applications, bone plates and fasteners are used to fuse bones, or bone parts, of the human body, such as bones in the foot, the ankle, the hand, the wrist, as well as various other portions of the body. Furthermore, during the course of certain medical procedures, a surgeon may immobilize one or more bones or the bone fragments by stabilizing the bones together in a configuration which approximates the natural anatomy. To this end, the surgeon may use fasteners to attach the bones to a bone plate implant so as to hold the bones in alignment with one another while they fuse together. Bone plant implants are taught in <CIT>, <CIT> and <CIT>.

The present invention relates to an apparatus for fusing bones as claimed hereafter.

The drawings refer to embodiments of the present disclosure in which:.

While the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The invention should be understood to not be limited to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure.

It will be apparent, however, to one of ordinary skill in the art that the invention disclosed herein may be practiced without these specific details. In other instances, specific numeric references such as "first plate," may be made. However, the specific numeric reference should not be interpreted as a literal sequential order but rather interpreted that the "first plate" is different than a "second plate. " Thus, the specific details set forth are merely exemplary. The specific details may be varied from and still be contemplated to be within the scope of the present invention as defined by the claims. The term "coupled" is defined as meaning connected either directly to the component or indirectly to the component through another component. Further, as used herein, the terms "about," "approximately," or "substantially" for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.

In general, the present disclosure describes an apparatus for fusing bones of the human body. The apparatus comprises a bone plate which comprises a member having one or more fixation apertures and one or more insert apertures. The bone plate is comprised of a semi-rigid material, such as a biocompatible metal or Polyetheretherketone (PEEK), possessing a tensile strength suitable for immobilizing bones. An insert is configured to be retained within the insert aperture. The insert is configured to direct a fastener towards an optimal point of bone purchase for fixating or compressing the bones. One insert is configured to direct a fastener at a substantially right angle relative to the bone plate. Active compression between bones can be accomplished by driving the fastener through an elongated slot in the insert ramped on one side. It will be appreciated that the fastener shall have a smooth (non-threaded) head so that this movement within the insert slot may be achieved.

Another insert is configured to direct a fastener at a substantially oblique angle to the bone plate. Fasteners are configured to be received into the one or more fixation apertures and driven into the bones so as to immobilize the bones. In some embodiments, the plate insert aperture is configured to receive a circular insert comprising threads configured to engage with threads of the insert aperture. The threads facilitate directing the insert fastener relative to a longitudinal axis of the fusion plate, in some instances directing the insert fastener at an angle across a fusion site between the adjacent bones and in some cases directing the fastener toward an optimal point of bone purchase. In some embodiments, the circular insert comprises at least one gripping hole configured to receive a distal protrusion of an insert driver. Engaging the distal protrusion into the gripping hole and twisting the insert driver facilitates rotating the circular insert within the insert aperture so as to attach the insert securely to the plate.

<FIG> illustrate an exemplary embodiment <NUM> of a bone plate <NUM> with a <NUM> degree fastener fixation insert <NUM> and an oblique fastener insert <NUM>, according to the present disclosure. The bone plate <NUM> comprises a generally elongate member having fixation apertures <NUM> suitable for receiving fasteners <NUM>. The bone plate <NUM> preferably is comprised of a semi-rigid material, such as a biocompatible metal or PEEK, possessing a tensile strength suitable for immobilizing adjacent bone parts of the human body.

As best illustrated in <FIG>, the bone plate <NUM> comprises an insert aperture <NUM> which is configured to receive either type of fixation insert <NUM>,<NUM>. In the embodiment illustrated in <FIG>, the inserts <NUM> and <NUM> are configured to be pressed into the insert aperture <NUM>. In some embodiments, however, the inserts <NUM> and <NUM> may be configured to be mechanically retained within the insert aperture <NUM>, such as by way of non-limiting example, through an incorporation of threads, recesses, tabs, notches, clips, as well as various protruding formations, and other similar constructs.

As illustrated in <FIG>, the oblique fastener insert <NUM> comprises a convertible insert aperture <NUM> which is configured to receive a fastener <NUM>, such that the threaded fastener <NUM> is directed at an oblique angle relative to a plane of the bone plate <NUM>. The oblique angle of the fastener <NUM> facilitates compressing adjacent bones together so as to encourage bone fusion. The fastener <NUM> may be any component of hardware having a head configured to abut the surface of bone plate <NUM> and a shaft configured to secure bones together in a fixed configuration. In some embodiments, the fastener <NUM> may comprise a nut and bolt assembly, a pin assembly, a bone screw, or other similar fastener suitable for use in bone. In some embodiments, the fastener <NUM> may comprise a lag screw which includes a head that is rounded or tapered coupled to a shaft having an unthreaded portion adjacent to the head and a threaded portion that ends at a tip.

<FIG> show the bone plate <NUM> with the insert <NUM> installed into the insert aperture <NUM>, such that the fastener <NUM> is directed at the oblique angle relative to the bone plate <NUM>, as described above. Alternatively, <FIG> show an exemplary embodiment <NUM> of the bone plate <NUM> with the fastener fixation insert <NUM> installed into the insert aperture <NUM>. The insert <NUM> comprises a fixation aperture <NUM> configured to direct a fixation screw <NUM> at a substantially right angle relative to the bone plate <NUM>, as best shown in <FIG>. It will be recognized that this insert <NUM> facilitates immobilizing adjacent bone parts. In some embodiments, the bone plate <NUM> and the insert <NUM> may be used with two or more fasteners <NUM> to fixate bones across a joint. It will be also appreciated that the fastener will have a smooth (non-threaded) so that lagging or compressing of bone fragments may be achieved.

In the embodiment illustrated in <FIG>, the insert aperture <NUM> comprises a countersunk edge which includes a round portion <NUM> and a flat portion <NUM> configured to orient and receive the inserts <NUM>, <NUM>. It will be appreciated that the round portion <NUM> and the flat portion <NUM> are configured to orient the inserts <NUM>, <NUM> advantageously within the bone plate <NUM>. In particular, the rounded portion <NUM> and the flat portion <NUM> orient the oblique fastener insert <NUM> such that the fastener <NUM> is directed along a majority of the length of the bone plate <NUM>, thereby providing greater support to the fasteners <NUM> and the bones to be fixated. Further, each of the fixation apertures <NUM> comprises a countersunk surface configured to receive a head of the fixation screw <NUM>, such that the fasteners <NUM> fixate the bone plate <NUM> to the bones.

The bone plate <NUM> illustrated in <FIG>, comprises a longitudinal rib <NUM> and a multiplicity of lateral ribs <NUM>. The ribs <NUM> and <NUM> serve to relieve stress on the bone plate <NUM> arising due to contact between the plate and the bones. The longitudinal rib <NUM> provides structural strength to the bone plate <NUM> so as to substantially inhibit bending along the length of the plate. The lateral ribs <NUM> support the contact at the longitudinal rib <NUM> and reduce contact between the plate and the bone.

<FIG> illustrate an exemplary embodiment <NUM> of a bone plate <NUM> coupled with a circular-shaped insert <NUM>. The bone plate <NUM> is substantially similar to the bone plate <NUM>, with the exception that the bone plate <NUM> comprises an insert aperture <NUM> which is configured to receive the circular insert <NUM>. As best illustrated in <FIG>, the circular insert <NUM> comprises threads <NUM> configured to rotatably engage with threads <NUM> of the insert aperture <NUM>. As will be appreciated, the threads <NUM>, <NUM> facilitate screwing the circular insert <NUM> into the insert aperture <NUM> and are configured to orient the circular insert relative to the bone plate for a desired fastener direction. In some embodiments, however, the circular insert <NUM> may be configured to be retained within the insert aperture <NUM>, such as by way of the example, through an incorporation of recesses, tabs, notches, clips, various protruding formations, as well as various countersunk surfaces suitable for press-fitting the circular insert <NUM> into the insert aperture <NUM>.

The circular insert <NUM> comprises an aperture <NUM> which is configured to receive the fastener <NUM>, such that the fastener <NUM> is directed at an oblique angle relative to the plane of the bone plate <NUM>. As described with reference to <FIG>, the oblique angle of the compression screw <NUM> facilitates compressing adjacent bones together so as to encourage bone fusion. Further, the circular insert <NUM>, as well as the threads <NUM>, <NUM>, facilitates rotating the compression screw <NUM> relative to a longitudinal dimension of the bone plate <NUM>, as illustrated in <FIG>. In the embodiment illustrated in <FIG>, the insert external threads <NUM> may be timed to orient the insert the fastener so that it is directed at an angle ranging between substantially <NUM> degrees and <NUM> degrees relative to the longitudinal dimension of the bone plate <NUM>. It will be appreciated that the circular insert <NUM> and the threads <NUM>, <NUM> facilitate directing the fastener <NUM> at various angles across a fusion site between adjacent bones. The fastener will have a smooth (non-threaded) so that a lagging or compressing of bone fragments may be achieved.

As best shown in <FIG> and <FIG>, the circular insert <NUM> comprises gripping holes <NUM>. In the embodiment of <FIG> and <FIG>, the circular insert <NUM> comprises two gripping holes <NUM>, although any number of gripping holes may be incorporated into the circular insert without deviating from the scope of the present disclosure. As best shown in <FIG>, the gripping holes <NUM> are configured to receive one or more distal protrusions <NUM> of an insert driver <NUM>. It should be understood that the insert driver <NUM> functions as a wrench, whereby the distal protrusions <NUM> may be engaged into the gripping holes <NUM> and then the insert driver <NUM> may be twisted so as to rotate the circular insert <NUM> within the insert aperture <NUM>. It should be further understood, therefore, that the gripping holes <NUM> and the insert driver <NUM> facilitate directing the compression screw <NUM> at various angles across a fusion site between adjacent bones, as discussed with reference to <FIG>.

<FIG> illustrate an exemplary embodiment of a bone plate <NUM> coupled with a circular-shaped insert <NUM>. The bone plate <NUM> is substantially similar to the bone plate <NUM>, with the exception that the bone plate <NUM> comprises an insert aperture <NUM> which is configured to receive the circular insert <NUM>. As best illustrated in <FIG>, the circular insert <NUM> comprises circumferential protrusions <NUM> configured to rotatably engage with a groove <NUM> of the insert aperture <NUM>. As will be appreciated, the circumferential protrusions <NUM> and the groove <NUM> facilitate engaging the circular insert <NUM> into the insert aperture <NUM> and are configured such that the circular insert may be positioned in various orientations relative to the bone plate. A countersink <NUM> within the insert aperture <NUM> maintains the circular insert <NUM> fastened within the bone plate <NUM>. In some embodiments, however, the circular insert <NUM> may be configured to be retained within the insert aperture <NUM>, such as by way of the example, through an incorporation of recesses, tabs, notches, clips, various protruding formations, as well as various countersunk surfaces suitable for press-fitting the circular insert <NUM> into the insert aperture <NUM>, as described herein.

The circular insert <NUM> comprises an aperture <NUM> which is configured to receive the fastener <NUM>, such that the fastener <NUM> is directed at an oblique angle relative to the plane of the bone plate <NUM>. As described with reference to <FIG>, the oblique angle of the fastener <NUM> facilitates compressing adjacent bones together so as to encourage bone fusion. Further, the circular insert <NUM>, as well as the circumferential protrusions <NUM> and the groove <NUM>, facilitates directing the fastener <NUM> at an angle relative to a longitudinal dimension of the bone plate <NUM>, as illustrated in <FIG>. In the embodiment illustrated in <FIG>, the circumferential protrusions <NUM> and the groove <NUM> are configured to orient the circular insert <NUM>, and thus the fastener <NUM> at an angle ranging between substantially <NUM> degrees and <NUM> degrees relative to the longitudinal dimension of the bone plate <NUM>. It will be appreciated that the circular insert <NUM>, the circumferential protrusions <NUM>, and the groove <NUM> facilitate directing the fastener <NUM> at various angles across a fusion site between adjacent bones. Moreover, the fastener <NUM> comprises a smooth, non-threaded portion, such that a lagging or compressing of bone fragments may advantageously be achieved.

As best shown in <FIG>, the circular insert <NUM> comprises gripping holes <NUM>. In the embodiment of <FIG>, the circular insert <NUM> comprises three gripping holes <NUM>, although any number of gripping holes may be incorporated into the circular insert without deviating from the scope of the present disclosure. It should be appreciated that the gripping holes <NUM> are substantially identical to the gripping holes <NUM>, described above in connection with <FIG>. As with the gripping holes <NUM>, the gripping holes <NUM> are configured to receive one or more distal protrusions of a suitable wrench, such as the insert driver <NUM>. The distal protrusions <NUM> may be engaged into the gripping holes <NUM> and then the insert driver <NUM> may be twisted so as to rotate the circular insert <NUM> within the insert aperture <NUM>. It should be further understood, therefore, that the gripping holes <NUM> and the insert driver <NUM>, or other suitable wrench, facilitate directing the fastener <NUM> at various angles across a fusion site between adjacent bones, as discussed herein.

As best illustrated in <FIG>, the bone plate <NUM> comprises a longitudinal rib <NUM> and a multiplicity of radial ribs <NUM>. The ribs <NUM> and <NUM> serve to relieve stress on the bone plate <NUM> arising due to contact between the plate and the bones. The longitudinal rib <NUM> provides structural strength to the bone plate <NUM> so as to substantially inhibit bending along the length of the plate. The radial ribs <NUM> support the contact at the longitudinal rib <NUM> and reduce contact between the plate and the bone. It will be appreciated that the longitudinal rib <NUM> is substantially similar to the longitudinal rib <NUM>, extending along the longitudinal dimension of the bone plate <NUM>. Further, the radial ribs <NUM> are substantially similar to the lateral ribs <NUM>, with the exception that each of the radial ribs <NUM> comprises a circular segment having a radius of curvature. In some embodiments, the radial ribs <NUM> all have the same radius of curvature. In some embodiments, the radial ribs <NUM> each has a unique radius of curvature. In some embodiments, each of the radial ribs <NUM> has a unique radius of curvature extending from substantially the center of the circular insert <NUM>, along the longitudinal rib <NUM>, to the radial rib.

Moreover, it should be recognized that the bone plate <NUM> is not to be limited to flat plates, but rather the bone plate <NUM> may comprise curvature along the longitudinal dimension of the bone plate <NUM>, curvature along a lateral dimension of the bone plate <NUM>, as well as a combination of curvatures along the longitudinal and lateral dimensions of the bone plate <NUM>. In some embodiments, the curvature may change along the longitudinal and lateral dimensions of the bone plate as a function of distance from the center of the insert aperture <NUM>. In some embodiments, the curvatures along the longitudinal and lateral dimensions of the bone plate <NUM> are selected to match a specific surface topology of a bone to be treated. Accordingly, it should be understood that the bone plate <NUM> may be implemented with any combination of topological features that fall within the scope of the claims.

It is envisioned that the embodiments discussed herein may be coupled with various surgical instruments that are configured for implanting the bone plates, inserts, and fasteners into patients. In some embodiments, the surgical instruments may include without limitation, plate trials, wires, drills, drill guides, depth gages, cup and cone reamers, screw drivers, plate benders, and the like. It is further envisioned that the bone plates, inserts, accompanying fasteners, and the selected surgical instruments are to be suitably sterilized for surgeries and packaged into sterilized containers. In some embodiments, the insert and the bone plate may be packaged in an assembled state into a first sterile container, the fasteners may be packaged into a second sterile container, and the instruments may be packaged into a third sterile container. The first, second, and third sterile containers may then be bundled together into a single, exterior container, thereby forming a convenient surgery-specific bone fusion implant package. In some embodiments, however, the bone plate and the insert may be packaged into separate sterile containers, thereby allowing a surgeon to assemble the bone plate and the insert before or during surgery. It is envisioned that other packaging techniques will be apparent to those skilled in the art without deviating from the scope of the claims.

Claim 1:
An apparatus for fusing bones of the human body, comprising:
a bone plate (<NUM>) having one or more fixation apertures (<NUM>) and an insert aperture (<NUM>);
a fastener fixation insert (<NUM>) having an aperture with a tapered, counter-bored, or countersunk internal shape configured to direct a fastener at a right angle relative to the bone plate and an oblique fastener insert (<NUM>) comprising an aperture with a tapered, counter-bored, or countersunk internal shape configured to receive a fastener, such that the fastener is directed at an oblique angle relative to a plane of the bone plate; and
the insert aperture (<NUM>) comprising a countersink edge and having a perimeter shape comprising a round portion (<NUM>) and a flat portion (<NUM>); and
one or more fixation screws (<NUM>) configured to be received into the one or more fixation apertures and driven into the bones so as to fixate or compress the bones, wherein one fixation aperture is configured to direct at least one fixation screw at a right angle relative to the bone plate; and
characterized in that:
the bone plate comprises a longitudinal rib (<NUM>) providing structural strength to the bone plate, and a multiplicity of lateral ribs (<NUM>) or a multiplicity of radial ribs (<NUM>) configured to minimize contact between the implant and the bone.