Patent Description:
The embodiments are generally directed to implants for supporting bone growth in a patient.

A variety of different implants are used in the body. Implants used in the body to stabilize an area and promote bone ingrowth provide both stability (i.e. minimal deformation under pressure over time) and space for bone ingrowth.

Spinal fusion, also known as spondylodesis or spondylosyndesis, is a surgical treatment method used for the treatment of various morbidities such as degenerative disc disease, spondylolisthesis (slippage of a vertebra), spinal stenosis, scoliosis, fracture, infection or tumor. The aim of the spinal fusion procedure is to reduce instability and thus pain.

In preparation for the spinal fusion, most of the intervertebral disc is removed. An implant, the spinal fusion cage, may be placed between the vertebra to maintain spine alignment and disc height. The fusion, i.e. bone bridge, occurs between the endplates of the vertebrae.

Wedge implants may also be used in other parts of the body to fuse adjacent bones other than vertebrae, or to fuse segments of a single bone such as for an opening wedge osteotomy. For example, wedge implants may also be used for osteotomy procedures, as well as sacroiliac (S. ) joint fusion or stabilization procedures.

Implants comprising bodies and bone contacting elements are for example known from documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

The present invention relates to a device as claimed hereafter. Preferred embodiments of the invention are set forth in the dependent claims. According to the invention, an implant includes a body, a first arched bone contacting element having two ends attached to the body; and a second arched bone contacting element having two ends attached to the body.

In another aspect, an implant includes a body including a lateral axis. The implant also includes a first arched bone contacting element oriented at a first angle with respect to the lateral axis and a second arched bone contacting element oriented at a second angle with respect to the lateral axis. The first angle is different from the second angle.

According to the invention, an implant includes a body comprising a peripheral structure, a first support beam and a second support beam. The peripheral structure bounds an interior region and the first support beam and the second support beam span the interior region. The implant also includes a first arched bone contacting element extending from a portion of the peripheral structure to the first support beam and a second arched bone contacting element extending from the first support beam to the second support beam.

In another aspect, an implant includes a body having a leading edge portion, a trailing edge portion, and an intermediate portion extending between the leading edge portion and the trailing edge portion. The leading edge portion includes a substantially smooth surface forming a substantial majority of a leading edge surface of the leading edge portion. The trailing edge portion includes a monolithic structure including at least one receptacle configured to receive an insertion tool. In addition, the intermediate portion includes a plurality of elongate curved structural members.

In another aspect, an implant includes a body having a leading edge portion, a trailing edge portion, and an intermediate portion extending between the leading edge portion and the trailing edge portion. The leading edge portion includes a substantially smooth surface forming a substantial majority of a leading edge surface of the leading edge portion. The trailing edge portion includes a monolithic structure including at least one receptacle configured to receive an insertion tool. In addition, the implant further includes at least one elongate substantially spiral member forming perimeter portions of the implant extending between the leading edge portion and the trailing edge portion.

In another aspect, an implant includes a body having a leading edge portion, a trailing edge portion, and an intermediate portion extending between the leading edge portion and the trailing edge portion. The leading edge portion includes a substantially smooth surface forming a substantial majority of a leading edge surface of the leading edge portion. The trailing edge portion includes a monolithic structure including at least one receptacle configured to receive an insertion tool. In addition, the implant includes at least one support beam extending between the leading edge portion and the trailing edge portion. Further, the implant includes at least one elongate substantially helical member extending between the leading edge portion and the trailing edge portion.

Other systems, methods (not claimed), features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods (not claimed), features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims.

The embodiments described herein are directed to implants including portions for insertion within recesses in bone. The portions configured for insertion within the recesses each include a body having a substrate or central portion and a multi-layer bone interfacing lattice. The layers of the bone interfacing lattice may include elongate curved structural members. Such structural members may have any of a variety of curved configurations. For example, the structural members may include portions that are helical, spiraled, coiled, sinusoidal, arched, or otherwise curved. Examples of such curved configurations are provided in the following applications.

In addition to the various provisions discussed below, any of the embodiments disclosed herein may make use of any of the body/support structures, frames, plates, coils or other structures disclosed in<CIT>, and titled "Implant with Protected Fusion Zones".

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates or other structures disclosed in<CIT>, and titled "Implant with Arched Bone Contacting Elements".

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates or other structures disclosed in<CIT>, and titled "Implant with Structural Members Arranged Around a Ring," and referred to herein as "The Ring application.

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates, or other structures disclosed in <CIT>, and titled "Coiled Implants and Systems and Methods of Use Thereof," and which is referred to herein as "The Coiled Implant Application.

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates, or other structures disclosed in <CIT>, and entitled "Implant with Bone Contacting Elements Having Helical and Undulating Planar Geometries".

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates, or other structures disclosed in <CIT>, and entitled "Corpectomy Implant".

Also, any of the embodiments disclosed herein may make use of any of the body/support structures, elements, frames, plates, or other structures disclosed in <CIT>, and entitled "Implant with Supported Helical Members".

<FIG> illustrate isometric views of an embodiment of implant <NUM>. Implant <NUM> may also be referred to as a cage or fusion device. In some embodiments, implant <NUM> is configured to be implanted within a portion of the human body. In some embodiments, implant <NUM> may be configured for implantation into the spine. In some embodiments, implant <NUM> may be a spinal fusion implant, or spinal fusion device, that is inserted between adjacent vertebrae to provide support and/or facilitate fusion between the vertebrae.

In some embodiments, implant <NUM> may include a body <NUM>. Body <NUM> may generally provide a frame or skeleton for implant <NUM>. According to the invention, implant <NUM> may also include a plurality of arched bone contacting elements <NUM>. Plurality of arched bone contacting elements <NUM> may be attached, and/or continuously formed (or "integrally formed") with, body <NUM>.

As used herein, each arched bone contacting element comprises a distinctive member or element that spans a region or area of an implant. In some embodiments, these elements may overlap or intersect, similar to elements in a lattice or other 3D mesh structure. In other embodiments, the elements may not overlap or intersect. Some embodiments may use elements in which the length of the element is greater than its width and its thickness. For example, in embodiments where an element has an approximately circular cross-sectional shape, the element has a length greater than its diameter. In the embodiments seen in <FIG>, each arched bone contacting element is seen to have an approximately rounded or circular cross-sectional shape (i.e., the element has the geometry of a solid tube) along at least a portion of the element. However, in other examples (not claimed), an element could have any other cross-sectional shape, including, but not limited to various polygonal cross-sectional shapes, as well as any other regular and/or irregular cross-sectional shapes. In some cases, for example, the cross-sectional shape of an arched bone contacting element could vary along its length (e.g., the diameter or shape could change along its length).

For purposes of clarity, reference is made to various directional adjectives throughout the detailed description and in the claims. As used herein, the term "anterior" refers to a side or portion of an implant that is intended to be oriented towards the front of the human body when the implant has been placed in the body. Likewise, the term "posterior" refers to a side or portion of an implant that is intended to be oriented towards the back of the human body following implantation. In addition, the term "superior" refers to a side or portion of an implant that is intended to be oriented towards a top (e.g., the head) of the body while "inferior" refers to a side or portion of an implant that is intended to be oriented towards a bottom of the body. Reference is also made herein to "lateral" sides or portions of an implant, which are sides or portions facing along lateral directions of the body following implantation.

In <FIG>, implant <NUM> is understood to be configured with an anterior side <NUM> and a posterior side <NUM>. Implant <NUM> may also include a first lateral side <NUM> and a second lateral side <NUM> that extend between the posterior side <NUM> and the anterior side <NUM> on opposing sides of implant <NUM>. Furthermore, implant <NUM> may also include a superior side <NUM> and an inferior side <NUM>.

Reference is also made to directions or axes that are relative to the implant itself, rather than to its intended orientation with regards to the body. For example, the term "distal" refers to a part that is located further from a center of an implant, while the term "proximal" refers to a part that is located closer to the center of the implant. As used herein, the "center of the implant" could be the center of mass and/or a central plane and/or another centrally located reference surface.

As used herein, the term "fixedly attached" shall refer to two components joined in a manner such that the components may not be readily separated (for example, without destroying one or both components).

An implant may also be associated with various axes. Referring to <FIG>, implant <NUM> may be associated with a lateral axis <NUM> that extends along implant <NUM> between first lateral side <NUM> and second lateral side <NUM>. Additionally, implant <NUM> may be associated with a posterior-anterior axis <NUM> that extends between posterior side <NUM> and anterior side <NUM>. Moreover, implant <NUM> may be associated with a vertical axis <NUM> that extends along the thickness dimension of implant <NUM> and which is generally perpendicular to both lateral axis <NUM> and posterior-anterior axis <NUM>.

An implant may also be associated with various reference planes or surfaces. As used herein, the term "median plane" refers to a vertical plane which passes from the anterior side to the posterior side of the implant, dividing the implant into right and left halves, or lateral halves. As used herein, the term "transverse plane" refers to a horizontal plane located in the center of the implant that divides the implant into superior and inferior halves. As used herein, the term "coronal plane" refers to a vertical plane located in the center of the implant that divides the implant into anterior and posterior halves. In some embodiments, the implant is symmetric about two planes, such as the transverse plane.

According to the invention, a body comprises a peripheral structure and one or more support beams that may extend from the peripheral structure. A peripheral structure may be comprised of any number of plates, walls or similar structures. In some embodiments the peripheral structure could comprise a ring. In other words, in some embodiments, the peripheral structure could be a peripheral ring structure. As seen in <FIG>, body <NUM> may be further comprised of a peripheral structure <NUM>. Peripheral structure <NUM> is seen to have a ring-like geometry.

<FIG> is a schematic isometric view of body <NUM> shown in isolation without any arched bone contacting elements and <FIG> is a schematic top view of body <NUM> in isolation from any arched bone contacting elements. Referring to <FIG>, peripheral structure <NUM> may be further comprised of an anterior side <NUM>, a posterior side <NUM>, a first lateral side <NUM> and a second lateral side <NUM>. As seen in <FIG>, in this exemplary embodiment, peripheral structure <NUM> is a continuous structure so that anterior side <NUM> is connected to first lateral side <NUM>, first lateral side <NUM> is connected to posterior side <NUM>, posterior side <NUM> is connected to second lateral side <NUM> and second lateral side <NUM> is connected to anterior side <NUM>. That is, anterior side <NUM>, first lateral side <NUM>, posterior side <NUM> and second lateral side <NUM> together form a continuous or unbroken ring.

<FIG> is a schematic front view of implant <NUM> while <FIG> is a schematic rear view of implant <NUM>. Referring now to <FIG>, anterior side <NUM> is further comprised of a first anterior portion <NUM> and a second anterior portion <NUM>. First lateral side <NUM> extends from first anterior portion <NUM> of anterior side <NUM> to posterior side <NUM>. Likewise, second lateral side <NUM> extends from second anterior portion <NUM> of anterior side <NUM> to posterior side <NUM>.

First anterior portion <NUM> is comprised of a distal surface <NUM> (best seen in <FIG>), a superior surface <NUM> and an inferior surface <NUM>. First anterior portion <NUM> also includes a first lateral surface <NUM> and a second lateral surface (not shown) opposite first lateral surface <NUM>. In addition, first anterior portion <NUM> includes a proximal surface <NUM> that is joined with a second support beam <NUM> as discussed below.

Second anterior portion <NUM> includes distal surface <NUM> (best seen in <FIG>), a superior surface <NUM> and an inferior surface (not shown). Second anterior portion <NUM> also includes a first lateral surface <NUM> (see <FIG>). In addition, second anterior portion <NUM> includes a proximal surface <NUM> that is joined with a third support beam <NUM> as discussed below. Moreover, second anterior portion <NUM> is disposed adjacent to first anterior portion <NUM>. In some embodiments, first anterior portion <NUM> and second anterior portion <NUM> are joined together.

Each of first lateral side <NUM> and second lateral side <NUM> comprise a distal surface joined with a proximal surface. In some cases, the proximal surface may be convex. For example, first lateral side <NUM> includes distal surface <NUM> and proximal surface <NUM>, where proximal surface <NUM> is convex and joined directly to distal surface <NUM> along the superior and inferior sides of implant <NUM>.

Posterior side <NUM> of implant <NUM> comprises a superior surface <NUM> and an inferior surface <NUM> (see <FIG>). Posterior side <NUM> also includes a distal surface <NUM> and a proximal surface <NUM>. As seen in <FIG>, the geometry of implant <NUM> at posterior side <NUM> tapers towards first lateral side <NUM> and second lateral side <NUM>.

In some embodiments, the vertical height or thickness of different portions of a peripheral structure could vary. In the embodiment shown in <FIG>, which shows a front schematic view of implant <NUM>, first anterior portion <NUM> is shown to have a first height <NUM> while second anterior portion <NUM> is shown to have a second height <NUM>. Here, first height <NUM> is seen to be greater than second height <NUM>. In some embodiments, this tapering in height from the centrally located first anterior portion <NUM> to the adjacent second anterior portion <NUM> helps give anterior side <NUM> of peripheral structure <NUM> a convex shape to better fit between adjacent vertebral bodies upon implantation.

Furthermore, as seen in <FIG>, the height of peripheral structure <NUM> along posterior side <NUM> is indicated as third height <NUM>. In the exemplary embodiment, third height <NUM> is less than first height <NUM>. Moreover, in some cases, third height <NUM> may be slightly less than second height <NUM>. In some embodiments, variations in height or vertical thickness between the posterior and anterior sides of an implant may allow for an implant with hyper-lordotic angles between the inferior and superior surfaces. In other embodiments, variations in vertical thickness may be used to control the relative rigidity of the device in different locations.

In some embodiments, the thickness of peripheral structure <NUM> may be smaller along both of first lateral side <NUM> and second lateral side <NUM> than along either of anterior side <NUM> or posterior side <NUM>. In the exemplary embodiment first lateral side <NUM> and second lateral side <NUM> have a similar fourth height <NUM>. Here, fourth height <NUM> is less than first height <NUM>, second height <NUM> and third height <NUM>. By using a reduced height or vertical thickness for the lateral sides as compared to the anterior and posterior sides, it is possible to attach arched bone contacting elements to the lateral sides while maintaining a smooth vertical profile across the superior and inferior surfaces of implant <NUM> (see <FIG>).

According to the invention, a body is provided with at least two support beams (or support structures) that act to reinforce a peripheral structure. In some embodiments, the support beams could be disposed along the interior of a peripheral structure. For example, in some embodiments, the support beams could extend from a first location on an inwardly (or proximally) facing surface of the support structure to a second location on the inwardly facing surface of the support structure. In other words, according to the invention, the support beams span an interior region bounded by the peripheral structure.

As seen in <FIG>, body <NUM> includes a plurality of support beams <NUM>. These include first support beam <NUM>, second support beam <NUM> and third support beam <NUM>. In the embodiment shown in <FIG>, each of these support beams extends from a first location on inwardly facing surface <NUM> of peripheral structure <NUM> to a second location on an inwardly facing surface of peripheral structure <NUM>. Here, it may be understood that the inwardly facing surface <NUM> of peripheral structure <NUM> is comprised of the proximal surfaces of the various sides of peripheral structure <NUM> (e.g., proximal surface <NUM>, proximal surface <NUM>, proximal surface <NUM>, etc.).

Referring to <FIG>, first support beam <NUM> includes a first end <NUM> attached to a first anterior location <NUM> of inwardly facing surface <NUM> and a second end <NUM> attached at a second anterior location <NUM> of inwardly facing surface <NUM>. Likewise, each of second support beam <NUM> and third support beam <NUM> include opposing ends attached to different locations along inwardly facing surface <NUM>. With this arrangement, plurality of support beams <NUM> are seen to span an interior region <NUM> (or central region) that is bounded by peripheral structure <NUM>.

The plurality of support beams <NUM> may be characterized as being centrally located within implant <NUM> with respect to peripheral structure <NUM>. As used herein, "centrally located" does not refer to a precise location that is at the geometric center or center of mass of an implant, but rather a general area or region disposed inwardly of a peripheral structure (e.g., within interior region <NUM>). Thus, in the following description and in the claims, a support beam may be referred to as a central beam.

In different embodiments, the number of support beams could vary. In some examples (not claimed), a single support beam could be used. In other embodiments, two or more support beams could be used. In the exemplary embodiment shown in <FIG>, three support beams are used.

In different embodiments, the orientation of one or more beams could vary. In some embodiments, two or more support beams could be oriented in parallel. In other embodiments, two or more support beams could be disposed at oblique angles to one another. In the exemplary embodiment, first support beam <NUM>, second support beam <NUM> and third support beam <NUM> may be disposed in parallel to one another. Moreover, in the exemplary embodiment, plurality of support beams <NUM> may be oriented in a posterior-anterior direction (i.e., along posterior-anterior axis <NUM>). Of course, in other embodiments, plurality of support beams <NUM> could be oriented in any other directions.

In different embodiments, the spacing, or separation, between adjacent support beams could vary. In some embodiments, the spacing between adjacent support beams could be small relative to the lateral width of an implant. For example, the spacing could range between <NUM>% and <NUM>% of the width of an implant. In other embodiments, the spacing between adjacent support beams could be large relative to the width of an implant. For example, the spacing could range between <NUM>% and <NUM>% of the width of an implant (for example, two beams located adjacent to opposing lateral sides of the implant may could be spaced apart by <NUM>% of the width of the implant). The spacing between adjacent beams (or between a beam and a portion of a peripheral structure) may be constant or may vary across an implant.

It may be appreciated that the relative spacing between support beams may be selected according to many factors, including the thicknesses of one or more support beams, the number of support beams used, the desired strength to weight ratio for an implant as well as other factors. Moreover, the spacing between adjacent support beams may be determined according to the dimensions of one or more arched bone contacting elements, since the arched bone contacting elements extend between adjacent support beams (or between a support beam and the peripheral structure).

In the embodiment shown in <FIG>, first support beam <NUM> is spaced apart from first lateral side <NUM> by a spacing <NUM>. First support beam <NUM> and second support beam <NUM> are spaced apart from one another by a spacing <NUM>. Second support beam <NUM> and third support beam <NUM> are spaced apart from one another by a spacing <NUM>. Third support beam <NUM> is spaced apart from second lateral side <NUM> by spacing <NUM>. In the exemplary embodiment, each of spacing <NUM>, spacing <NUM>, spacing <NUM> and spacing <NUM> generally have a value in the range between <NUM>% and <NUM>% of width <NUM> of implant <NUM>. Of course it may be appreciated that each spacing is an average or approximate spacing, since the spacing between adjacent components can vary, for example, along posterior-anterior axis <NUM>.

In different embodiments, the geometry of one or more support beams could vary. In some embodiments, one or more support beams could have a curved geometry. In other embodiments, one or more support beams could have a substantially straight geometry. In the embodiment shown in <FIG>, each of plurality of support beams <NUM> has a substantially straight geometry. Moreover, the cross-sectional geometry of each support beam is substantially rounded. However, in other embodiments, one or more support beams could have any other cross-sectional shape, including but not limited to: rectangular shapes, polygonal shapes, regular shapes and/or irregular shapes. The cross-sectional shapes could also vary across a length of a support beam from, for example, a rounded cross-sectional shape (e.g., circular or elliptic) to a polygonal cross-sectional shape (e.g., rectangular).

In different embodiments, the thickness of one or more support beams could vary. Generally, the thickness (or diameter) of a support beam could vary in a range between <NUM>% and <NUM>% of the width (or length) of an implant. In the exemplary embodiment, first support beam <NUM>, second support beam <NUM> and third support beam <NUM> have diameters in a range approximately between <NUM>% and <NUM>% of width <NUM> of implant <NUM>, as seen in <FIG>. More specifically, second support beam <NUM> has a diameter <NUM> that is greater than a diameter <NUM> of first support beam <NUM> and also that is greater than a diameter <NUM> of third support beam <NUM>. In some cases, second support beam <NUM> may have the largest diameter. Because impact forces are applied at the center of implant <NUM> (where second support beam <NUM> is located) by a device coupled to implant <NUM> at first interior portion <NUM>, this greater diameter for second support beam <NUM> may help reinforce the center of implant <NUM>.

In at least some embodiments, support beams in the body of an implant may be coplanar. In <FIG>, first support beam <NUM>, second support beam <NUM> and third support beam <NUM> are seen to reside in a similar plane of implant <NUM>. The coplanar arrangement of support beams may help provide a generally symmetric arrangement for implant <NUM> between the superior and inferior sides.

Generally, the geometry of one or more portions of the body of an implant could vary from one embodiment to another. For example, portions of a body can include one or more windows, slots and/or openings that may facilitate bone growth through the implant and/or may reduce weight.

Some embodiments can include one or more fastener receiving provisions. Some embodiments can include one or more attachment openings that may engage an insertion or implantation device. In some embodiments, an implant can include one or more threaded cavities. In some embodiments, a threaded cavity can be configured to mate with a corresponding threaded tip on an implantation tool or device. In other embodiments, a threaded cavity can receive a fastener for purposes of fastening an implant to another device or component in an implantation system that uses multiple implants and/or multiple components.

As best seen in <FIG>, implant <NUM> includes a first threaded cavity <NUM> disposed in first anterior portion <NUM>. Implant <NUM> also includes second threaded cavity <NUM> disposed in second anterior portion <NUM>. In some embodiments, first threaded cavity <NUM> may receive the threaded tip of an implantation tool (not shown). Such a tool could be used to drive implant <NUM> between adjacent vertebral bodies. Optionally, in some cases, implant <NUM> may also include a pair of indentations (indentation <NUM> and indentation <NUM>) that may facilitate alignment between an implantation tool and implant <NUM>. In some embodiments, second threaded cavity <NUM> could be used to fasten implant <NUM> to a separate component (not shown) of a broader implantation system. For example, some embodiments could incorporate a separate plate that may be fastened to implant <NUM> using a fastener secured within first threaded cavity <NUM> or second threaded cavity <NUM>. Such a plate could include additional fixation members (e.g., screws) that could be used with the implant.

According to the invention, an arched bone contacting element includes a first end portion, an intermediate portion and a second end portion. In some embodiments, the intermediate portion may have an arched geometry. In such cases, an intermediate portion having an arched geometry may be referred to as an "arched portion". According to the invention, at least one of the first end portion and/or the second end portion has a flared geometry. In such cases, an end having a flared geometry may be referred to as a "flared leg" of the arched bone contacting element.

<FIG> is a schematic view of an exemplary arched bone contacting element seen in isolation, including several enlarged schematic cross-sectional views taken at various locations of the element. Referring to <FIG>, arched bone contacting element <NUM> is comprised of a first end portion, which is referred to as a first flared leg <NUM>. Arched bone contacting element <NUM> is also comprised of an arched portion <NUM>. Additionally, arched bone contacting element <NUM> is comprised of a second end portion, which is referred to as a second flared leg <NUM>.

In some embodiments, an arched bone contacting element can include provisions for engaging a vertebral body following implantation. In some embodiments, one or more arched bone contacting elements can include at least one distal surface region that is configured to directly contact a vertebral endplate. In some cases, a distal surface region could be a flattened surface region. In other cases, a distal surface region could be a convex surface region. In still other cases, a distal surface region could be a concave surface region. More generally, a distal surface region could have a different curvature from the adjacent surface regions of an arched portion. Moreover, the particular curvature for a distal surface region could be selected to match the local geometry of an opposing vertebral endplate.

As an example, in <FIG>, arched bone contacting element <NUM> is seen to include a distal surface region <NUM> that is located in arched portion <NUM>. In some embodiments, distal surface region <NUM> may have a convex curvature that is smaller than the curvature of adjacent regions of arched portion <NUM>. Similarly, as best seen in <FIG>, the remaining arched bone contacting elements of implant <NUM> are also configured with distal bone contacting regions having a smaller curvature than adjacent surface regions of arched portion <NUM> (i.e., these distal surface regions may be flatter than the remaining regions of arched portion <NUM>, but may not be completely flat). Together, these distal bone contacting regions provide a partial smooth surface that can engage a vertebral body. Moreover, in some embodiments, the collection of flattened (or convex) bone contacting regions together form a minimal contact surface with the bone and thereby allow for an increased amount of graft material or bone growth promoting material to be placed in direct contact with the bone. Specifically, bone growth promoting material that is disposed in between arched bone contacting elements, including being disposed in the open regions along the superior and inferior surfaces, may directly contact the bone.

For purposes of reference, arched bone contacting element <NUM> may be characterized as having a curved central axis <NUM>. As used herein, the curved central axis of an element is an axis that extends along the length of the element and is located at an approximate center of the element at each location along its length. It may be understood that the cross-sections discussed below and shown in <FIG> are taken along planes that are perpendicular to curved central axis <NUM>.

As seen in <FIG>, arched portion <NUM> has an arched geometry. Arched portion <NUM> is also seen to have a rounded cross-sectional shape. More specifically, in some cases, arched portion <NUM> has an approximately circular (or near-circular) cross-sectional shape. In some embodiments, the diameter and cross-sectional shape of arched portion <NUM> stays relatively constant along much of the length of arched portion <NUM> (i.e., along curved central axis <NUM>). However, it may be understood that the cross-sectional shape of arched portion <NUM> could vary, for example, along flattened bone contacting region <NUM>. For reference, a cross-section of arched portion <NUM> taken at reference plane <NUM> is shown in <FIG>. Of course, in other embodiments, arched portion <NUM> could have any other cross-sectional shape.

At each flared leg, the cross-sectional shape of arched bone contacting element <NUM> may vary. For example, as seen in <FIG>, the cross-sectional shape of first flared leg <NUM> has a first cross-sectional shape <NUM> at a location adjacent arched portion <NUM> (taken at reference plane <NUM>). First flared leg <NUM> also has a second cross-sectional shape <NUM> and a third cross-sectional shape <NUM>. Here, the third cross-sectional shape <NUM> is taken at a location furthest from arched portion <NUM> (taken at reference plane <NUM>), and second cross-sectional shape <NUM> is taken at an intermediate location along first flared leg <NUM> (taken at reference plane <NUM>).

As shown in <FIG>, the cross-sectional shape of first flared leg <NUM> varies from an approximately circular cross-sectional shape (i.e., first cross-sectional shape <NUM>) to an approximately elliptic cross-sectional shape (i.e., third cross-sectional shape <NUM>). For example, the first cross-sectional shape <NUM> of first flared leg <NUM> has a similar diameter <NUM> along both a first axis <NUM> and a second axis <NUM>. However, the second cross-sectional shape <NUM> has a major diameter <NUM> along first axis <NUM> that is greater than its minor diameter <NUM> along second axis <NUM>. Furthermore, the third cross-sectional shape <NUM> also has a major diameter <NUM> along first axis <NUM> and a minor diameter <NUM> along second axis <NUM>, where major diameter <NUM> is greater than major diameter <NUM> and minor diameter <NUM> is greater than minor diameter <NUM>. Thus, the cross-sectional size of first flared leg <NUM> increases as its shape also changes from an approximately circular shape to an approximately elliptic shape.

With the arrangement described above, the cross-sectional area of arched bone contacting element <NUM> may be a minimum in arched portion <NUM>. Moreover, moving along curved central axis <NUM> from arched portion <NUM> to first flared leg <NUM>, the cross-sectional area increases through first flared leg <NUM> until reaching a maximum at the furthest end of first flared leg <NUM> (and similarly reaching a maximum at the furthest end of second flared leg <NUM>).

This increase in cross-sectional area provides for a wider base for each arched bone contacting element at its attachment to the body and can thus improve the strength of the attachment between the arched bone contacting element and the body. Moreover, the variation in cross-sectional shape allows the increase in size to be primarily directed in a direction parallel with the underlying structure (e.g., a support beam or a section of the peripheral structure). For example, as seen in <FIG>, first flared leg <NUM> has a longest dimension parallel with a central axis <NUM> of peripheral segment <NUM> to which first flared leg <NUM> is attached. Here, peripheral segment <NUM> is a segment of implant <NUM>. Moreover, first flared leg <NUM> has a smallest dimension parallel with a widthwise axis <NUM> of peripheral segment <NUM>. Thus, the surface area of the attachment between arched bone contacting element <NUM> and peripheral segment <NUM> is increased while preventing first flared leg <NUM> from extending beyond peripheral segment <NUM> in the direction of widthwise axis <NUM>.

While the geometry of first flared leg <NUM> is discussed in detailed, it may be appreciated that second flared leg <NUM> may have a similar geometry to first flared leg <NUM>. Likewise, the flared legs of the remaining arched bone contacting elements of implant <NUM> may also have similar geometries to first flared leg <NUM>.

The particular cross-sectional geometries (circular and elliptic) illustrated for portions of an arched bone contacting element in <FIG> are only intended to be schematic representations of possible variations in geometry for an arched bone contacting element. In some embodiments, a flared leg could have a more irregular geometry, which while increasing in size and becoming elongated along one axis, does not have a substantially elliptic cross-sectional shape. Moreover, the cross-sectional shape could change between any two shapes at opposing ends of the flared leg. Exemplary cross-sectional shapes include, but are not limited to: rounded (including circular and elliptic), rectangular, polygonal, regular, irregular as well as any other shapes.

Embodiments could include any number of arched bone contacting elements. Some embodiments may include a single arched bone contacting element. Still other embodiments could include any number of arched bone contacting elements in the range between <NUM> and <NUM>. In still further embodiments, an implant could include more than <NUM> elements. In the exemplary embodiment shown in <FIG>, implant <NUM> includes <NUM> arched bone contacting elements, including nine elements on superior side <NUM> and nine elements on inferior side <NUM>. The number of arched bone contacting elements used can vary according to factors including implant size, desired implant strength, desired volume for bone graft or other bone growth promoting materials as well as possibly other factors.

In different embodiments, the arrangement of arched bone contacting elements in an implant could vary. In some embodiments, arched bone contacting elements could attach to any portions of a peripheral structure, to any beams of an implant, as well as other arched bone contacting elements. In some embodiments, an arched bone contacting element could extend across the entire width of an implant. In other embodiments, an arched bone contacting element may only extend across a portion of the width of an implant.

In order to enhance strength in an implant, some embodiments may use arched bone contacting elements that only extend between adjacent beams or between a beam and an adjacent portion of a peripheral structure.

<FIG> is a schematic top view of implant <NUM>. Referring to <FIG>, plurality of arched bone contacting elements <NUM> includes a superior set of arched bone contacting elements <NUM> and an inferior set of arched bone contacting element <NUM> (visible in <FIG>). Superior set <NUM> is further comprised of a first group of arched bone contacting elements <NUM> (or simply, first group <NUM>), a second group of arched bone contacting elements <NUM> (or simply second group <NUM>), a third group of arched bone contacting elements <NUM> (or simply third group <NUM>) and a fourth group of arched bone contacting elements <NUM> (or simply fourth group <NUM>). In the embodiment of <FIG>, each group of arched bone contacting elements includes two or more elements that extend between the same two beams or between the same beam and the same side of peripheral structure <NUM>.

As seen in <FIG>, first group <NUM> includes first arched bone contacting element <NUM>, second arched bone contacting element <NUM> and third arched bone contacting element <NUM>. Each of these elements extends between first lateral side <NUM> of peripheral structure <NUM> and first support beam <NUM>. For example, first arched bone contacting element <NUM> has a flared leg <NUM> attached to first lateral side <NUM> and a flared leg <NUM> attached to first support beam <NUM>. Similarly, each of second arched bone contacting element <NUM> and third arched bone contacting element <NUM> have one flared leg attached to first lateral side <NUM> and another flared leg attached to first support beam <NUM>.

Second group <NUM> includes fourth arched bone contacting element <NUM> and fifth arched bone contacting element <NUM>. Each of these elements extends between first support beam <NUM> and second support beam <NUM>. For example, fourth arched bone contacting element <NUM> has a flared leg <NUM> attached to first support beam <NUM> and another flared leg <NUM> attached to second support beam <NUM>. Similarly, fifth arched bone contacting element <NUM> has a flared leg attached to first support beam <NUM> and another flared leg attached to second support beam <NUM>.

Third group <NUM> includes sixth arched bone contacting element <NUM> and seventh arched bone contacting element <NUM>. Each of these elements extends between second support beam <NUM> and third support beam <NUM>. For example, sixth arched bone contacting element <NUM> has a flared leg <NUM> attached to second support beam <NUM> and another flared leg <NUM> attached to third support beam <NUM>. Similarly, seventh arched bone contacting element <NUM> has a flared leg attached to second support beam <NUM> and another flared leg attached to third support beam <NUM>.

Fourth group <NUM> includes eighth arched bone contacting element <NUM> and ninth arched bone contacting element <NUM>. Each of these elements extends between third support beam <NUM> and second lateral side <NUM> of peripheral structure <NUM>. For example, eighth arched bone contacting element <NUM> has a flared leg <NUM> attached to third support beam <NUM> and another flared leg <NUM> attached to second lateral side <NUM>. Similarly, ninth arched bone contacting element <NUM> has a flared leg attached to third support beam <NUM> and another flared leg attached to second lateral side <NUM>.

In some cases, some portions of adjacent arched bone contacting elements could be in contact or partially overlap. For example, some embodiments could have flared legs that are in contact or partially overlap. As an example, in <FIG>, flared leg <NUM> is disposed adjacent to, and in partial contact with flared leg <NUM>. It may be appreciated, though, that each arched bone contacting element attaches at its ends to portions of the body of implant <NUM>.

Although the ends of two or more arched bone contacting elements may be in contact with one another, the arched portions of each element remain separated from adjacent elements. In other words, there is no intersection between the arched portions of different arched bone contacting elements. Specifically, in some embodiments, the arched portion of each arched bone contacting element may be non-intersecting or separated from one another. Also, there is no intersection of arched bone contacting elements at or near the regions where the arched bone contacting elements contact the vertebrae. Thus it may be seen that implant <NUM> provides a plurality of arched bone contacting elements <NUM> that are non-intersecting and are arranged to be in contact with an opposing vertebral surface.

Some embodiments may include provisions that allow a structure to be self-supporting during manufacturing, for example, when the structure is manufactured using a 3D printing process. In some embodiments, the arrangement of arched bone contacting elements may be selected to facilitate self-support during manufacturing (e.g., during a 3D printing process). In some embodiments, the arched bone contacting elements can be arranged in angled orientations relative to the body or an axis of the body. In some embodiments, the arched bone contacting elements may be arranged into a herringbone-like pattern that is further comprised of individual V-like configurations of elements. Such a configuration may enable the implant to be printed with self-supporting structures.

One or more arched bone contacting elements may be angled with respect to one or more axes of an implant. Referring to <FIG>, for example, second arched bone contacting element <NUM> is oriented at an oblique angle with respect to lateral axis <NUM> (and also with respect to posterior-anterior axis <NUM>). Additionally, fourth arched bone contacting element <NUM> is oriented at an oblique angle with respect to lateral axis <NUM> (and also with respect to posterior-anterior axis <NUM>). Moreover, second bone contacting element <NUM> and fourth bone contacting element <NUM> are oriented at different angles from lateral axis <NUM>. As shown in <FIG>, the remaining arched bone contacting elements may also be oriented at an oblique angle with respect to lateral axis <NUM> of implant <NUM>. Thus it may be seen that the arched bone contacting elements are not arranged in parallel on implant <NUM>.

In some embodiments, at least two arched bone contacting elements may be arranged in a V-like configuration, or pattern, on a body of an implant. For example, second arched bone contacting element <NUM> and fourth arched bone contacting element <NUM> are arranged in a first V-like configuration <NUM>. Additionally, sixth arched bone contacting element <NUM> and eighth arched bone contacting element <NUM> are arranged in a second V-like configuration <NUM>. Also, third arched bone contacting element <NUM> and fifth arched bone contacting element <NUM> are arranged in a third V-like configuration <NUM>. Finally, seventh arched bone contacting element <NUM> and ninth arched bone contacting element <NUM> are arranged in a fourth V-like configuration <NUM>. Although the present embodiment includes four V-like configurations on the superior side (i.e., superior set of arched bone contacting elements <NUM>), as well as another four V-like configurations on the inferior side, other embodiments could include any other number of V-like configurations on the superior side or the inferior side.

In different embodiments, the positioning and orientation of V-like configurations could vary. In some embodiments, all of the V-like configurations may be oriented in a similar direction. In other embodiments, two or more V-like configurations could be oriented in different directions. Moreover, in some cases, two or more V-like configurations could be arranged in rows and/or columns.

In the embodiment shown in <FIG>, each V-like configuration has a common orientation corresponding to the posterior-anterior axis <NUM>. Specifically, each configuration is arranged such that the tip of the V points along posterior-anterior axis <NUM> and in the direction towards posterior side <NUM>. Moreover, first V-like configuration <NUM> and second V-like configuration <NUM> are disposed adjacent to one another in a first row such that they have different positions along lateral axis <NUM>. Likewise, third V-like configuration <NUM> and fourth V-like configuration <NUM> are disposed adjacent to one another in a second row. Furthermore, first V-like configuration <NUM> and third V-like configuration <NUM> are disposed adjacent to one another in a first column such that they have different positions along posterior-anterior axis <NUM>. Likewise, second V-like configuration <NUM> and fourth V-like configuration <NUM> are disposed adjacent one another in a second column. As seen in <FIG>, when considered together, the four V-like configurations form a larger herringbone pattern <NUM> on body <NUM>.

Each V-like configuration may be centered around a single support beam. For example, first V-like configuration <NUM> and second V-like configuration may be centered around first support beam <NUM>. Also, third V-like configuration and fourth V-like configuration may be centered around third support beam <NUM>.

Each V-like configuration may extend from a lateral side of body <NUM> to a central support beam (e.g., second support beam <NUM>). For example, first V-like configuration <NUM> extends from first lateral side <NUM> to second support beam <NUM>. And second V-like configuration <NUM> extends from second support beam <NUM> to second lateral side <NUM>.

In some cases, orienting arched bone contacting elements into a herringbone pattern may facilitate easier insertion of the implant. In particular, by angling the arched bone contacting elements away from the lateral direction, the elements may present a smaller surface area along the implantation direction (i.e., the posterior direction), which could potentially ease insertion effort.

The arrangement of arched bone contacting elements may also be designed to achieve a desired total open volume. As used herein a total volume is the combined volume of any openings between arched bone contacting elements, any openings in the body, or between arched bone contacting elements and the body. This open configuration may facilitate bone growth in and through the implant. A portion or all of the open spaces is optionally filled with a bone graft or bone growth promoting material prior to or after insertion of the implant to facilitate bone growth.

The total volume of the open spaces (also referred to simply as the open space volume) within any particular implant is dependent on the overall dimension of the implant as well as the size and dimension of individual components within the implant including arched bone contacting elements. The open space volume may range from about <NUM>% to <NUM>% of the volume of the implant. In some embodiments, implant <NUM> may have an open space volume that is between <NUM>% and <NUM>% of the implant's total volume. In still further embodiments, implant <NUM> may have an open space volume that is between <NUM>% and <NUM>% of the total implant volume.

In some embodiments, an implant can be configured with one or more symmetries. In some cases, an implant may have a mirrored symmetry about one or more reference planes. In other cases, an implant may have a translational symmetry about one or more reference planes. In still other cases, an implant could have both a mirror symmetry and a translational symmetry.

Referring to <FIG> and <FIG>, implant <NUM> may include at least one mirror symmetry. For purposes of reference, implant <NUM> may be split into a superior half and an inferior half. Here, the "superior half" of implant <NUM> includes the portions of body <NUM> and plurality of arched bone contacting elements <NUM> disposed above the transverse plane. Likewise, the "inferior half" of implant <NUM> includes the portions of body <NUM> and plurality of arched bone contacting elements <NUM> disposed below the transverse.

With respect to the transverse plane (which coincides generally with body <NUM> in this embodiment), it may be seen that the superior half of implant <NUM> mirrors the inferior half of implant <NUM>. This includes not only the geometry of the body but also the shape, size and orientations of each arched bone contacting element. It may be appreciated that this mirror symmetry may only be approximate in some embodiments. The symmetric configuration of implant <NUM>, for example the mirror symmetry between the superior and inferior halves of implant <NUM>, may help to balance loads in the vertical direction, or the direction along the length of the spine.

In different embodiments, the dimensions of an implant can vary. Exemplary dimensions that could be varied include length, width and thickness. Moreover, in some cases, the diameter of one or more arched bone contacting elements could vary from one embodiment to another.

<FIG> is a schematic view of another embodiment of an implant <NUM>. Implant <NUM> may be similar in many ways to implant <NUM> discussed above and shown in <FIG>. In some embodiments, implant <NUM> may have a greater width and length (and thus a larger overall footprint) than implant <NUM>. In order to accommodate the larger size, implant <NUM> may include an additional arched bone contacting element <NUM> on superior side <NUM>, as well as a corresponding element on an inferior side (not shown).

As seen in <FIG>, arched bone contacting element <NUM> extends from support beam <NUM> to lateral side <NUM> of implant <NUM>. With this additional arched bone contacting element, group of arched bone contacting elements <NUM> on lateral side <NUM> is seen to have the same number of elements (i.e., three) as group of arched bone contacting elements <NUM> on lateral side <NUM>. This configuration of arched bone contacting elements is thus seen to have a mirror symmetry about a central axis <NUM> of implant <NUM>.

<FIG> illustrate a schematic view of another embodiment of an implant <NUM>. Implant <NUM> may be similar in many ways to implant <NUM> and implant <NUM> discussed above and shown in <FIG>. In some embodiments, implant <NUM> may have a greater width and length (and thus a larger overall footprint) than implant <NUM>.

Some embodiments can include one or more arched bone contacting elements that are attached at both ends to a single support beam. Some embodiments can include one or more arched bone contacting elements that are attached to a single segment of a peripheral structure.

Referring to <FIG>, implant <NUM> is comprised of a plurality of arched bone contacting elements <NUM> attached to a body <NUM>. Body <NUM> is further comprised of a peripheral structure <NUM>, a first support beam <NUM>, a second support beam <NUM> and a third support beam <NUM>.

Referring now to <FIG>, plurality of arched bone contacting elements <NUM> is further comprised of a first group of arched bone contacting elements <NUM> (or first group <NUM>), a second group of arched bone contacting elements <NUM> (or second group <NUM>), a third group of arched bone contacting elements <NUM> (or third group <NUM>), a fourth group of arched bone contacting elements <NUM> (or fourth group <NUM>), a fifth group of arched bone contacting elements <NUM> (or fifth group <NUM>), a sixth group of arched bone contacting elements <NUM> (or sixth group <NUM>), a seventh group of arched bone contacting elements <NUM> (or seventh group <NUM>) and an eighth group of arched bone contacting elements <NUM> (or eighth group <NUM>).

Second group <NUM> includes arched bone contacting elements extending from first lateral side <NUM> of peripheral structure <NUM> to first support beam <NUM>. Fourth group <NUM> includes arched bone contacting elements extending from first support beam <NUM> to second support beam <NUM>. Fifth group <NUM> includes arched bone contacting elements extending from second support beam <NUM> to third support beam <NUM>. Seventh group <NUM> includes arched bone contacting elements extending from third support beam <NUM> to second lateral side <NUM> of peripheral structure <NUM>. Moreover, the arched bone contacting elements in second group <NUM>, fourth group <NUM>, fifth group <NUM> and seventh group <NUM> are generally arranged into V-like configurations organized into a herringbone-like pattern, similar to the arrangement of arched bone contacting elements of implant <NUM>.

As implant <NUM> has an increased footprint compared to implant <NUM> and implant <NUM>, additional arched bone contacting elements may be included to provide a larger (partial) contact surface on the superior and inferior sides of implant <NUM>. In the embodiment shown in <FIG>, some of these additional arched bone contacting elements are added along the lateral sides of body <NUM> as well as first support beam <NUM>, second support beam <NUM> and third support beam <NUM>.

First group <NUM> includes an arched bone contacting element <NUM> and an arched bone contacting element <NUM>, which are both connected at each end to first lateral side <NUM> of peripheral structure <NUM>. Specifically, for example, arched bone contacting element <NUM> includes a first flared leg <NUM> attached to first lateral side <NUM> and a second flared leg <NUM> attached to first lateral side <NUM>.

Additionally, third group <NUM> includes three arched bone contacting elements, each of which are attached at both ends to first support beam <NUM>. For example, arched bone contacting element <NUM> includes first flared leg <NUM> attached to first support beam <NUM> and a second flared leg <NUM> attached to first support beam <NUM>. Likewise, sixth group <NUM> includes three arched bone contacting elements. Each of these elements includes two flared legs that are both attached at third support beam <NUM>. Additionally, eighth group <NUM> includes two arched bone contacting elements. Each of these elements includes two flared legs that are both attached at second lateral side <NUM> of peripheral structure <NUM>.

Embodiments can include provisions for texturing one or more surfaces of an implant. Such texturing can increase or otherwise promote bone growth and/or fusion to surfaces of the implant. In some embodiments, arched bone contacting elements and/or sections of a body may be textured.

In some embodiments, the surface structure of one or more regions of an implant may be roughened or provided with irregularities. Generally, this roughened structure may be accomplished through the use of acid etching, bead or grit blasting, sputter coating with titanium, sintering beads of titanium or cobalt chrome onto the implant surface, as well as other methods. In some embodiments, the roughness can be created by 3D printing a raised pattern on the surface of one or more regions of an implant. In some embodiments, the resulting roughened surface may have pores of varying sizes. In some embodiments, pore sizes could range between approximately <NUM> and <NUM>. In one embodiment, pore sizes could be approximately <NUM>. Of course in other embodiments, surface roughness comprising pore sizes less than <NUM> and/or greater than <NUM> are possible.

An embodiment using textured surfaces is shown in an isometric view of an alternative embodiment and implant <NUM> seen in <FIG>. As seen in <FIG>, implant <NUM> includes a smooth peripheral surface <NUM>. The remaining surfaces of implant <NUM>, however, have been roughened. These include the visible portions of superior surface <NUM>, which is further comprised of superior surfaces of peripheral structure <NUM> and the surfaces of plurality of arched bone contacting elements <NUM>. For purposes of illustration, the roughened surfaces are indicated schematically using stippling. These roughened or porous surfaces may help improve bone growth along surfaces of the implant. As a particular example, arched bone contacting element <NUM> is seen to have a roughened surface region <NUM> (also seen in the enlarged schematic view of <FIG>) that extends through the entire element including distal surface region <NUM> which is intended to directly contact an adjacent vertebra.

It may be appreciated that any of the embodiments illustrated in the Figures can include one or more roughened surfaces. For example, in some embodiments implant <NUM>, implant <NUM> or implant <NUM> could include one or more roughened surfaces. Moreover, the roughened surfaces could be selectively applied to some portions of an implant but not others.

In some embodiments, bone growth can be facilitated by applying a bone growth promoting material in or around portions of an implant. As used herein, a "bone growth promoting material" (or BGPM) is any material that helps bone growth. Bone growth promoting materials may include provisions that are freeze dried onto a surface or adhered to the metal through the use of linker molecules or a binder. Examples of bone growth promoting materials are any materials including bone morphogenetic proteins (BMPs), such as BMP-<NUM>, BMP-<NUM>, BMP-<NUM>, BMP-<NUM>, and BMP-<NUM>. These are hormones that convert stem cells into bone forming cells. Further examples include recombinant human BMPs (rhBMPs), such as rhBMP-<NUM>, rhBMP-<NUM>, and rhBMP-<NUM>. Still further examples include platelet derived growth factor (PDGF), fibroblast growth factor (FGF), collagen, BMP mimetic peptides, as well as RGD peptides. Generally, combinations of these chemicals may also be used. These chemicals can be applied using a sponge, matrix or gel.

Some bone growth promoting materials may also be applied to an implantable prosthesis through the use of a plasma spray or electrochemical techniques. Examples of these materials include, but are not limited to, hydroxyapatite, beta tri-calcium phosphate, calcium sulfate, calcium carbonate, as well as other chemicals.

A bone growth promoting material can include, or may be used in combination with a bone graft or a bone graft substitute. A variety of materials may serve as bone grafts or bone graft substitutes, including autografts (harvested from the iliac crest of the patient's body), allografts, demineralized bone matrix, and various synthetic materials.

Some embodiments may use autograft. Autograft provides the spinal fusion with calcium collagen scaffolding for the new bone to grow on (osteoconduction). Additionally, autograft contains bone-growing cells, mesenchymal stem cells and osteoblast that regenerate bone. Lastly, autograft contains bone-growing proteins, including bone morphogenic proteins (BMPs), to foster new bone growth in the patient.

Bone graft substitutes may comprise synthetic materials including calcium phosphates or hydroxyapatites, stem cell containing products which combine stem cells with one of the other classes of bone graft substitutes, and growth factor containing matrices such as INFUSE® (rhBMP-<NUM>-containing bone graft) from Medtronic, Inc.

It should be understood that the provisions listed here are not meant to be an exhaustive list of possible bone growth promoting materials, bone grafts or bone graft substitutes.

In some embodiments, BGPM may be applied to one or more outer surfaces of an implant. In other embodiments, BGPM may be applied to internal volumes within an implant. In still other embodiments, BGPM may be applied to both external surfaces and internally within an implant.

In some embodiments, the implant may be configured for implantation as part of an opening osteotomy procedure. In such embodiments, the implant may be substantially wedge-shaped. To facilitate implantation, the leading edge (i.e., the narrow end) of the wedge may have a substantially smooth surface. In addition, in order to receive an elongate insertion tool, the trailing edge (i.e., the thicker end) of the wedge may have a monolithic structure. The monolithic structure may include a receptacle configured to receive an insertion tool, for example, via a threaded connection.

<FIG> is a schematic illustration of an osteotomy procedure involving the implantation of a wedge implant. As shown in <FIG>, an implant <NUM> may be substantially wedge-shaped. As part of an opening osteotomy procedure, a bone, such as tibia <NUM>, may be cut on one side, and pried open to create a recess <NUM> in the bone. Implant <NUM> may be inserted into recess <NUM> to fill in the gap and, thereby, effectively lengthen one side of the bone. That is, the bone may have a first side <NUM> and a second side <NUM>. Recess <NUM> may be created in first side <NUM>, and thus, insertion of wedge-shaped implant <NUM> effectively lengthens first side <NUM> of tibia <NUM>. This lengthening of one side of a bone can correct malformations, whether congenital or due to trauma or disease. For example, the lengthening of a lateral or medial side of the tibia can correct for conditions such as bowlegs or knock-knees. Such procedures can also be used to treat osteoarthritis on one side of the knee, by shifting a person's weight to the healthy side of the knee.

<FIG> is a schematic leading edge perspective view of implant <NUM>. As shown in <FIG>, implant <NUM> may include a body <NUM>. Body <NUM> may have a leading edge portion <NUM>, a trailing edge portion <NUM>, and an intermediate portion <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>.

Implant <NUM> may be used in osteotomy procedures in a number of anatomical locations. Accordingly, the directional references are provided with respect to a plurality of axes. In particular, implant <NUM> may have a length extending from leading edge portion <NUM> to trailing edge portion <NUM> along a longitudinal axis <NUM>, as shown in <FIG>. As also shown in <FIG>, implant <NUM> may have a width extending along a lateral axis <NUM> perpendicular to longitudinal axis <NUM>. Further, implant <NUM> may have a thickness in a third dimension along a third axis <NUM> perpendicular to longitudinal axis <NUM> and lateral axis <NUM>.

In some embodiments, the leading edge of the implant may include provisions to facilitate insertion of the implant between opposing sides of a bone recess. For example, the leading edge may be provided with a bullnose feature. That is, the leading edge may include a substantially smooth surface forming a substantial majority of a leading edge surface of the leading edge portion.

As shown in <FIG>, leading edge portion <NUM> may have a leading edge surface <NUM> that is substantially smooth across a substantial majority of leading edge portion <NUM>. In some embodiments, the substantially smooth leading edge surface <NUM> may extend the entire thickness of leading edge portion <NUM> in the direction of third axis <NUM>, as shown in <FIG>. As further shown in <FIG>, leading edge surface <NUM> may be substantially rounded in the direction of third axis <NUM>. (See also <FIG>. ) As also shown in <FIG>, in some embodiments, leading edge surface <NUM> may be rounded in the direction of lateral axis <NUM>. (See also <FIG>.

The implant may include provisions for receiving an insertion tool. For example, some embodiments can include a monolithic structure in the trailing edge of the implant. The monolithic structure can include one or more receptacles configured to engage an insertion or implantation tool. In some embodiments, such receptacles may include female threads configured to engage insertion or implantation tools.

<FIG> is a schematic trailing edge perspective view of the implant <NUM>. As shown in <FIG>, trailing edge <NUM> may include a monolithic structure <NUM>. Monolithic structure <NUM> may including a receptacle <NUM> configured to receive an insertion tool (see, e.g., <FIG> for an exemplary insertion tool). In some embodiments, receptacle <NUM> may include female threading <NUM> configured to receive male threading on an insertion tool.

The implant may include provisions to promote bone ingrowth. For example, in some embodiments, the implant may include a plurality of elongate curved structural members. Spaces may be defined between the elongate curved structural members to permit bone ingrowth in between and around the elongate curved structural members. In some embodiments, the elongate curved structural members may have any of a variety of curved configurations. For example, the structural members may include portions that are helical, spiraled, coiled, sinusoidal, arched, or otherwise curved.

As shown in <FIG>, in some embodiments, implant <NUM> may include one or more elongate curved structural members <NUM>. As shown in <FIG>, elongate curved structural members <NUM> may be substantially spiral members, such as a first spiral member <NUM> and a second spiral member <NUM>. The two spiral members may be substantially concentric about third axis <NUM>. For example, as shown in <FIG>, first spiral member <NUM> may be an outer spiral forming perimeter portions of implant <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>. Second spiral member <NUM> may be an inner spiral. As shown in <FIG>, first spiral member <NUM> and second spiral member <NUM> may have substantially the same gauge (e.g., wire diameter). In other embodiments, first spiral member <NUM> and second spiral member <NUM> may be formed with different gauges.

Elongate curved structural members <NUM> may provide longitudinal compressive strength to implant <NUM>. That is, since implant <NUM> is inserted in the direction of longitudinal axis <NUM> by pushing it toward leading edge portion <NUM> with an insertion tool from trailing edge portion <NUM>, implant <NUM> may be subjected to significant longitudinal compressive forces. Accordingly, elongate curved structural members <NUM> may be configured to withstand such compressive forces and to maintain an amount of rigidity that enables insertion of leading edge portion <NUM> without buckling or undue compression of intermediate portion <NUM>. Accordingly, the gauge, material, and geometrical shape of elongate curved structural members <NUM> may be selected to provide the longitudinal compressive strength desired for the intended implantation location.

First spiral member <NUM> may have a substantially tapered thickness in the direction of third axis <NUM>, providing implant <NUM> with its substantially wedge-shaped configuration. As shown in <FIG>, second spiral member <NUM> may have a substantially constant thickness in the direction of third axis <NUM>. Due to one spiral member having a tapered thickness and the other spiral member having a constant thicknesses, in at least one area of the implant, the two spirals will have different thicknesses. For example, one end of the implant may be provided with a difference in thickness of the two spirals. As shown in <FIG>, in the leading edge end of implant <NUM>, first spiral member <NUM> and second spiral member <NUM> may have substantially the same thickness, whereas, in the trailing edge end of implant <NUM>, first spiral member <NUM> and second spiral member <NUM> have different thicknesses, with first spiral member <NUM> having a larger thickness than second spiral member <NUM>. In the configuration of <FIG>, with an inner spiral member having a smaller thickness than the outer spiral member, a hollowed central region <NUM> of implant <NUM> may be provided, which may facilitate use of bone graft material.

<FIG> is a schematic lateral view of the implant <NUM>. As shown in <FIG>, the body of implant <NUM> may be substantially wedge-shaped. That is, the thickness of implant <NUM> may be tapered. For example, as shown in <FIG>, implant <NUM> may have a first thickness <NUM> proximate leading edge portion <NUM>, and a second thickness <NUM> at trailing edge portion <NUM>, wherein second thickness <NUM> is greater than first thickness <NUM>.

In addition, it will be noted that, as shown in <FIG>, first thickness <NUM> of implant <NUM> is completely formed by the substantially smooth leading edge surface <NUM> of leading edge portion <NUM>. In addition, the previously discussed rounded profile of leading edge surface <NUM> is also clearly shown in <FIG>. Both of these features may facilitate insertion of implant <NUM> into a recess in bone.

<FIG> is a schematic leading edge view of implant <NUM>. Previously discussed hollow central region <NUM> is shown from a different perspective in <FIG>.

<FIG> is a schematic trailing edge view of implant <NUM>. <FIG> illustrates the relative proportions of trailing edge portion <NUM>. For example, in in some embodiments, trailing edge portion <NUM> may have a thickness <NUM> that extends a substantial majority of second thickness <NUM> of elongate curved structural members <NUM> in the trailing edge end of implant <NUM>.

In addition to having a wedge configuration due to varying thickness in third axis <NUM>, the perimeter portions of implant <NUM> may define a substantially teardrop shape. The substantially teardrop shape may be suitable for implantation in certain bone locations. For example, the substantially teardrop shape may be suitable for implantation in a tibial osteotomy due to the curved nature of the outer surface of the tibia at the location the osteotomy is typically performed. In other embodiments, implants having different shapes may be used. For example, implants having substantially square or rectangular shapes may be used, particularly where the surface of the bone in which the implant is to be inserted has a less rounded surface.

<FIG> is a schematic leading edge perspective view of another embodiment of an implant. <FIG> shows an implant <NUM>. Implant <NUM> may have a substantially square shape. As shown in <FIG>, implant <NUM> may include a body <NUM>. Body <NUM> may have a leading edge portion <NUM>, a trailing edge portion <NUM>, and an intermediate portion <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>.

As shown in <FIG>, leading edge portion <NUM> may have a leading edge surface <NUM> that is substantially smooth across a substantial majority of leading edge portion <NUM>. In some embodiments, the substantially smooth leading edge surface <NUM> may extend the entire thickness of leading edge portion <NUM> in the direction of third axis <NUM>, as shown in <FIG>. As further shown in <FIG>, leading edge surface <NUM> may be substantially rounded in the direction of third axis <NUM>.

<FIG> is a schematic illustration of another osteotomy procedure. In <FIG>, the implantation of implant <NUM> is depicted. As shown in <FIG>, implant <NUM> may be implanted as part of an opening osteotomy procedure performed on a cuneiform bone in the foot, such as medial cuneiform <NUM>. As also shown in <FIG>, implant <NUM> may have a substantially wedge-shaped configuration in which the trailing edge end has a greater thickness than the leading edge end of implant <NUM>. Accordingly, implant <NUM> may be inserted into a recess <NUM> in medial cuneiform <NUM>.

<FIG> includes a schematic trailing edge perspective view of implant <NUM>. As shown in <FIG>, trailing edge <NUM> may include a monolithic structure <NUM>. Monolithic structure <NUM> may include a receptacle <NUM> configured to receive an insertion tool (see, e.g., <FIG> for an exemplary insertion tool). In some embodiments, receptacle <NUM> may include female threading <NUM> configured to receive male threading on an insertion tool. Also, in some embodiments, implant <NUM> may include one or more inserter features similar to indentations <NUM> and <NUM> shown in <FIG>.

As shown in <FIG>, instead of a single large spiral member providing the entire thickness of the implant, implant <NUM> may have a plurality of elongate curved structural members <NUM> stacked in the direction of third axis <NUM>. Elongate curved structural members <NUM> may include a plurality of spiral members. One or more of the spiral members may form perimeter portions of implant <NUM>, as shown in <FIG>. Also, one or more of the spiral members may extend between leading edge portion <NUM> and trailing edge portion <NUM>. Accordingly, such spiral members may provide implant <NUM> with longitudinal compressive strength to maintain structural integrity during insertion into an osteotomy recess.

<FIG> is a schematic illustration of another osteotomy procedure involving the implantation of implant <NUM>. As shown <FIG>, an osteotomy procedure may be performed on other bones a foot <NUM>, such as a calcaneus <NUM>. Such an osteotomy procedure may create a recess <NUM> in calcaneus <NUM>. Implant <NUM> may be configured (and sized) for insertion into recess <NUM>.

<FIG> also shows an insertion tool <NUM>, configured to engage receptacle <NUM> of implant <NUM>. For example, insertion tool <NUM> may include male threads <NUM> configured to engage the female threads in receptacle <NUM>.

<FIG> is a schematic trailing edge perspective view of another embodiment of a wedge type implant. As shown in <FIG>, an implant <NUM> may have substantially the same structure as implant <NUM>. For example, implant <NUM> may include a body <NUM>. Body <NUM> may have a leading edge portion <NUM>, a trailing edge portion <NUM>, and an intermediate portion <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>. Body <NUM> may also include a plurality of elongate curved structural members <NUM>.

As shown in <FIG>, implant <NUM> may also include a first structural support beam <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>. Along with elongate curved support members <NUM>, first structural support beam <NUM> may provide longitudinal compressive strength to implant <NUM>. In some embodiments, implant <NUM> may include more than one structural support beam. For example, implant <NUM> may include a second structural support beam <NUM>. As shown in <FIG>, first structural support beam <NUM> and second structural support beam <NUM> may be disposed on opposing lateral sides of implant <NUM>. In some embodiments, the structural support beams may be disposed within one or more of elongate support members <NUM>. For example, as shown in <FIG>, first structural support member <NUM> may be disposed within a first spiral member <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>.

As shown in <FIG>, implant <NUM> may also include a structural support beam <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>. Along with elongate curved support members <NUM>, first structural support beam <NUM> may provide longitudinal compressive strength to implant <NUM>.

Wedge type implants may be used in other surgical procedures. For example, wedge type implants may be used in sacroiliac joint stabilization procedures. Such implants may be inserted between the sacrum and ilium in order to immobilize or fuse the joint between these two bones. Such implants may have provisions to facilitate insertion. For example, such implants may have a substantially wedge-shaped configuration, and may include a bullnose leading edge and a monolithic trailing edge portion configured to engage an insertion tool. In addition, such implants may have provisions to promote bone ingrowth. For example, such implants may include a plurality of elongate curved structural members arranged to define spaces between the structural members. This open structure may promote bone ingrowth between and around the elongate curved structural members.

<FIG> is a schematic illustration of a sacroiliac joint stabilization procedure involving the implantation of a wedge implant. As shown in <FIG>, an implant <NUM> may be substantially wedge-shaped. As part of a sacroiliac joint stabilization procedure, the sacroiliac joint <NUM> between the sacrum <NUM> and the ilium <NUM> may be stabilized by inserting implant <NUM> between these two bones.

As shown in <FIG>, an insertion tool <NUM> may be used to deliver implant <NUM> into sacroiliac joint <NUM>. Insertion tool <NUM> may be configured to engage a trailing edge portion of implant <NUM> and may be utilized to drive into and orient implant <NUM> with respect to sacroiliac joint <NUM>. In some embodiments, insertion tool <NUM> may engage with implant <NUM> via a threaded connection.

Although, implant <NUM> is illustrated as implantable for sacroiliac stabilization procedures, such an implant with the same or similar configuration may be used in a variety of medical procedures, such as osteotomy procedures, bone fusion procedures, etc. Accordingly, the directional references are provided with respect to a plurality of axes. In particular, implant <NUM> may have a length extending from leading edge portion <NUM> to trailing edge portion <NUM> along a longitudinal axis <NUM>, as shown in <FIG>. As also shown in <FIG>, implant <NUM> may have a width extending along a lateral axis <NUM> perpendicular to longitudinal axis <NUM>. Further, implant <NUM> may have a thickness in a third dimension along a third axis <NUM> perpendicular to longitudinal axis <NUM> and lateral axis <NUM>.

In some embodiments, the leading edge of the implant may include provisions to facilitate insertion of the implant between opposing bones of the sacroiliac joint. For example, the leading edge may be provided with a bullnose feature. That is, the leading edge may include a substantially smooth surface forming a substantial majority of a leading edge surface of the leading edge portion.

As shown in <FIG>, leading edge portion <NUM> may have a leading edge surface <NUM> that is substantially smooth across a substantial majority of a width of leading edge portion <NUM>. As shown in <FIG>, in some embodiments, leading edge surface <NUM> may be rounded in the direction of lateral axis <NUM>.

Leading edge portion <NUM> may have a substantially tapered thickness in the direction of third axis <NUM>, providing implant <NUM> with its substantially wedge-shaped configuration. That is, leading edge portion <NUM> may have a first thickness <NUM> and trailing edge portion <NUM> may have a second thickness <NUM>. As shown in <FIG>, second thickness <NUM> may be greater than first thickness <NUM>.

As shown in <FIG>, in some embodiments, implant <NUM> may include one or more elongate curved structural members <NUM>. As shown in <FIG>, elongate curved structural members <NUM> may include at least one elongate curved structural member <NUM> extending longitudinally from leading edge portion <NUM> to trailing edge portion <NUM> of implant <NUM>. As further shown in <FIG>, in some embodiments, elongate curved structural member <NUM> may have a substantially sinusoidal configuration. Accordingly, elongate curved structural member <NUM> may curve back and forth in the direction of third axis <NUM>. The sinusoidal configuration may provide open spaces on opposing sides of the structural member to facilitate bone ingrowth, receive bone graft material, or both. As shown in <FIG>, in some embodiments, implant <NUM> may include a plurality of sinusoidal structural members having opposing curvatures. That is, where a first structural member curves in a first direction, the adjacent structural member may curve in the opposite direction.

<FIG> is a schematic trailing edge perspective view of implant <NUM>. As shown in <FIG>, trailing edge <NUM> may include a monolithic structure <NUM>. Monolithic structure <NUM> may including a receptacle <NUM> configured to receive an insertion tool (see, e.g., <FIG> for an exemplary insertion tool). In some embodiments, receptacle <NUM> may include female threading <NUM> configured to receive male threading on an insertion tool.

The implant can be formed with elongate curved structural members having a variety of configurations. <FIG> illustrate several embodiments that implement substantially the same leading edge portion and trailing edge portion as implant <NUM>, but which include differing elongate curved structural members.

<FIG> is a schematic leading edge perspective view of another embodiment of an implant. <FIG> illustrates an implant <NUM> having a body <NUM>. Body <NUM> may have a leading edge portion <NUM>, a trailing edge portion <NUM>, and an intermediate portion <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>. Implant <NUM> may also include a plurality of elongate curved structural members <NUM>.

One or more of elongate curved structural members <NUM> may have a sinusoidal configuration. For example, a first sinusoidal structural member <NUM> and a second sinusoidal member <NUM> may extend between leading edge portion <NUM> and trailing edge portion <NUM>. As shown in <FIG>, first sinusoidal structural member <NUM> and second sinusoidal member <NUM> may curve back and forth in a lateral direction. First sinusoidal structural member <NUM> and second sinusoidal member <NUM> may also provide longitudinal compressive strength to implant <NUM>. In addition, in some embodiments, a portion of one or more of elongate curved structural members <NUM> may have a substantially helical configuration.

As shown in <FIG>, in some embodiments, plurality of elongate curved structural members <NUM> may include one or more substantially helical members longitudinally from leading edge portion <NUM> to trailing edge portion <NUM>. For example, implant <NUM> may include a first substantially helical member <NUM>, a second substantially helical member <NUM>, and a third substantially helical member <NUM> extending between leading edge portion <NUM> and trailing edge portion <NUM>.

In some embodiments, implant <NUM> may include one or more structural support beams. For example, as also shown in <FIG>, implant <NUM> may include a first structural support beam <NUM> and a second structural support beam <NUM>. First structural support beam <NUM> and second structural support beam <NUM> may provide implant <NUM> with longitudinal compressive strength. In addition, first structural support beam <NUM> and second structural support beam <NUM> may also provide a framework upon which one or more of the substantially helical members may be disposed.

As shown in <FIG>, implant <NUM> may include a first structural support beam <NUM> and a second structural support beam <NUM>. First structural support beam <NUM> and second structural support beam <NUM> may provide implant <NUM> with longitudinal compressive strength. In addition, first structural support beam <NUM> and second structural support beam <NUM> may also provide a framework upon which one or more of the elongate curved structural members may be disposed.

As shown in <FIG>, in some embodiments, implant <NUM> may include a central wall portion <NUM> disposed between leading edge portion <NUM> and trailing edge portion <NUM> of implant <NUM>. Central wall portion <NUM> may span between first structural support beam <NUM> and second structural support beam <NUM>, thus forming a framework. Thus, central wall portion <NUM> may provide structural strength to implant <NUM> both by adding a structural member to form a framework, and by shortening the length of the elongate curved structural members. Further, elongate curved structural members <NUM> may be substantially symmetrically arranged on opposing sides of central wall portion <NUM>, as shown in <FIG>. This may ensure that the strength of implant <NUM> is consistent along a substantial majority of the longitudinal length of implant <NUM>.

As shown in <FIG>, implant <NUM> may include a plurality of structural support beams extending between leading edge portion <NUM> and trailing edge portion <NUM>. For example, implant <NUM> may include a first structural support beam <NUM> and a second structural support beam <NUM>. Implant <NUM> may also include a third structural support beam <NUM> and a fourth structural support beam <NUM> extending. Since first structural support beam <NUM>, second structural support beam <NUM>, third structural support beam <NUM>, and fourth structural support beam <NUM> extend between leading edge portion <NUM> and trailing edge portion <NUM>, these structural support beams may provide implant <NUM> with longitudinal compressive strength. In addition, these structural support beams may also provide a framework upon which one or more of the elongate curved structural members may be disposed.

As shown in <FIG>, elongate curved structural members <NUM> and the structural support beams may be configured in a rib-cage structure, defining an interior volume of space. The interior volume of space may be configured to receive bone graft material and facilitate the ingrowth of bone around the support members of implant <NUM>.

As shown in <FIG>, implant <NUM> may include a plurality of structural support beams extending between leading edge portion <NUM> and trailing edge portion <NUM>. For example, implant <NUM> may include a first structural support beam <NUM>, a second structural support beam <NUM>, and a third structural support beam <NUM>. Since first structural support beam <NUM>, second structural support beam <NUM>, and third structural support beam <NUM> extend between leading edge portion <NUM> and trailing edge portion <NUM>, these structural support beams may provide implant <NUM> with longitudinal compressive strength. In addition, these structural support beams may also provide a framework upon which one or more of the elongate curved structural members may be disposed.

The various components of an implant may be fabricated from biocompatible materials suitable for implantation in a human body, including but not limited to, metals (e.g. titanium or other metals), synthetic polymers, ceramics, and/or their combinations, depending on the particular application and/or preference of a medical practitioner.

Generally, the implant can be formed from any suitable biocompatible, non-degradable material with sufficient strength. Typical materials include, but are not limited to, titanium, biocompatible titanium alloys (e.g. γTitanium Aluminides, Ti6-Al4-V ELI (ASTM F <NUM>), or Ti6-Al4-V (ASTM F <NUM> and ASTM F <NUM>)) and inert, biocompatible polymers, such as polyether ether ketone (PEEK) (e.g. PEEK-OPTIMA®, Invibio Inc). Optionally, the implant contains a radiopaque marker to facilitate visualization during imaging.

Claim 1:
An implant (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), comprising:
a body (<NUM>) including a peripheral structure (<NUM>) bounding an interior region (<NUM>), and a first support beam (<NUM>) extending through the interior region; and a second support beam (<NUM>) extending through the interior region;
a first arched bone contacting element (<NUM>, <NUM>, <NUM>), that spans a region or area of the implant and defines pores for promoting bone growth having two ends fixedly attached to the first support beam; and
a second arched bone contacting element (<NUM>, <NUM>, <NUM>), that spans a region or area of the implant and defines pores for promoting bone growth, having two ends fixedly attached to the first support beam;
wherein the first arched bone contacting element includes an arched portion (<NUM>) and at least one flared leg (<NUM>);
wherein the at least one flared leg includes a first portion fixedly attached to the body and a second portion proximate the arched portion; and wherein the first portion has a first cross-sectional shape (<NUM>) and wherein the second portion has a second cross-sectional shape (<NUM>) that is different than the first portion cross-sectional shape (<NUM>); and
wherein the first cross-sectional shape is elliptic and the second cross-sectional shape is circular.