Patent ID: 12193717

DETAILED DESCRIPTION OF SELECTED EXAMPLES

The following detailed description and the appended drawings describe and illustrate various example bone plates, bone plate systems, methods of treatment, and methods of manufacturing a bone plate. The description and drawings are provided to enable one skilled in the art to make and use one or more example bone plates and bone plate systems, and to perform one or more example methods of treatment and methods of manufacturing a bone plate. They are not intended to limit the scope of the claims in any manner.

As used herein, the term “porous,” and grammatically related terms, refers to a macro structural configuration of a component or portion of a component in which the material of the component or portion of a component defines a series of passageways into which material, such as a liquid, can enter. The passageways can be randomly distributed throughout the component or portion of a component, or can be distributed throughout the component or portion of a component in an ordered fashion. As an example, a lattice structure created during 3D printing of a metal component or portion of a metal component provides a porous structure consistent with this definition of “porous.” The term does not include micro structural pores that naturally occur in the material that comprises the component or portion of a component.

As used herein, the term “non-porous,” and grammatically related terms, refers to a macro structural configuration of a component or portion of a component in which the material of the component or portion of a component does not define a series of passageways into which material, such as a liquid, can enter.

FIGS.1,2and3illustrate an example bone plate100. The bone plate100has a main body110having a first end112, a second end114, and a lengthwise axis101extending between the first end112and the second end114. The main body110has first116and second118opposing surfaces, and defines a plurality of passageways120. Each passageway120a,120b,120c,120d,120e,120f,120gof the plurality of passageways120extends through the entire thickness of the main body110, from the first surface116to the second surface118. As such, each passageway120a,120b,120c,120d,120e,120f,120gprovides a through opening within which another component can be disposed, such as a bone screw useful in securing the bone plate100across a fracture in a bone as part of a fixation procedure.

The main body110defines a circumferential wall122a,122b,122c,122d,122e,122f,122gfor each passageway120a,120b,120c,120d,120e,120f,120gof the plurality of passageways120. Each circumferential wall122a,122b,122c,122d,122e,122f,122gbounds a respective passageway120a,120b,120c,120d,120e,120f,120g.

The main body110includes a non-porous portion130and a porous portion150. In the illustrated example, the non-porous portion130is a continuous portion of the main body110, while the porous portion150comprises a plurality of discrete porous portions150a,150b,150c,150d,150e,150f,150g. Each circumferential wall122a,122b,122c,122d,122e,122f,122gis cooperatively formed by the non-porous portion130and one of the discrete porous portions150a,150b,150c,150d,150e,150f,150g. As best illustrated inFIGS.2and3, circumferential wall122gis recessed within passageway120g, providing a countersink structure for screw180. Non-porous portion130of the main body110defines the upper portion124of the circumferential wall122g, while porous portion150gdefines the lower portion126of the circumferential wall122g. The lower portion126forms a part of the lower surface118of the main body110. Thus, in this embodiment, lower surface118is cooperatively formed by the non-porous portion130and the porous portion150, via discrete porous portions150a,150b,150c,150d,150e,150f,150g.

This structural configuration of the circumferential wall122gis considered advantageous at least because it positions the porous portion150gof the circumferential wall122gbeneath the non-porous portion130of the circumferential wall122gwith respect to the opposing surfaces116,118. As best illustrated inFIG.3, with respect to passageway120g, this enables the thread182of screw180to deform the structure of the porous portion150gas the screw180is driven into the passageway120g, effectively forming a thread in the porous portion150gthat mates with the thread182of the screw180. The non-porous portion130ensures that the head184of the screw180does not pass through the opening, as the non-porous portion130will resist the deformation that the porous portion150gpermits.

In the illustrated example, each circumferential wall122a,122b,122c,122d,122e,122f,122ghas a similar structure to that described above for circumferential wall122g, with porous portion150a,150b,150c,150d,150e,150f,150gbeneath the non-porous portion130with respect to the opposing surfaces116,118. It is noted, though, that bone plates according to other examples can include circumferential walls having different structures. For example, it may be desirable to include one or more circumferential walls having a thread that is fully formed by the non-porous portion of a bone plate according to an embodiment in addition to a circumferential wall having the structural configuration described above. Inclusion of such a circumferential ensures that at least one thread is available that does not require thread forming action by a screw during placement of the bone plate, which may be desirable. Inclusion of at least one circumferential wall having the structural configuration described and illustrated above is considered advantageous at least because it ensures that at least one screw will be installed with thread forming action, providing desirable securement and bony ingrowth properties for the bone plate.

A bone plate according to an embodiment can include any suitable number of passageways. A skilled artisan will be able to select an appropriate number of passageways for a bone plate according to a particular embodiment based on various considerations, including the anatomical location at which the bone plate is intended to be used. The inclusion of seven passageways in the bone plate100illustrated inFIGS.1through3is merely an example of a suitable number of passageways. Similarly, a bone plate according to an embodiment can have any suitable overall shape. A skilled artisan will be able to select an appropriate shape for a bone plate according to a particular embodiment based on various considerations, including the anatomical location at which the bone plate is intended to be used. The elongate strip shape of the bone plate100illustrated inFIGS.1through3is merely an example of a suitable overall shape.

The porous portion in a bone plate according to a particular embodiment can have any suitable dimensions, and a skilled artisan will be able to select appropriate dimensions for a porous portion in a bone plate according to a particular embodiment based on various considerations, including the function of the porous portion. For example, in embodiments in which the porous portion forms a portion of the circumferential wall bounding a screw passageway and is to deform in response to a screw being driven through the passageway, the inventors have determined that a porous portion having a thickness of between about 1 mm and 2 mm is suitable for a passageway having an inner diameter of 4 mm. In embodiments in which the porous portion forms a boundary for a cavity into which a support member is to be formed, such as by injection molding, the inventors have determined that a porous portion having a thickness of between about 0.5 mm and 1 mm is suitable.

FIG.4illustrates another example bone plate200. The bone plate200is similar to the bone plate100illustrated inFIGS.1through3and described above, except as detailed below. Thus, bone plate200has a main body210having a first end212, a second end214, and a lengthwise axis201extending between the first end212and the second end214. The main body210has first216and second218opposing surfaces, and defines a plurality of passageways220. For illustrative purposes only, the bone plate200is positioned in the opposite orientation of the bone plate100inFIGS.1through3, such that the second surface218is upright and the first surface216is downward. Each passageway220a,220b,220cof the plurality of passageways220extends through the entire thickness of the main body210, from the first surface216to the second surface218. As such, each passageway220a,220b,220cprovides a through opening within which another component can be disposed, such as a bone screw useful in securing the bone plate200across a fracture in a bone as part of a fixation procedure.

The main body210defines a circumferential wall222a,222b,222cfor each passageway220a,220b,220cof the plurality of passageways220. Each circumferential wall222a,222b,222cbounds a respective passageway220a,220b,220c.

The main body210includes a non-porous portion230and a porous portion250. The non-porous portion230is a continuous portion of the main body210. In this example, and in contrast to first example bone plate100, porous portion250is also a continuous portion of the main body210. Each circumferential wall222a,222b,222cis cooperatively formed by the non-porous portion230and the porous portion250. Each circumferential wall222a,222b,222cis recessed within a respective passageway220a,220b,220c, providing a countersink structure for a bone screw. Non-porous portion230of the main body210defines the upper portion224a,224b,224cof each circumferential wall222a,222b,222c, while porous portion250defines the lower portion226a,226b,226cof each circumferential wall222a,222b,222c. The lower portion226a,226b,226cof each circumferential wall222a,222b,222cis continuous and flush with the lower surface218of the main body210. Lower surface218is cooperatively formed by the non-porous portion230and the porous portion250. In this example, non-porous portion230forms a perimeter edge255of the lower surface218.

This structural configuration is considered advantageous at least because it provides the desirable thread forming capability of the porous portion250in the passageways while also positioning the porous portion250on the majority of the lower surface218of the main body210, which is the bone-contacting surface of the bone plate200. The porous structure of the porous portion250provides structure that is advantageous for bony ingrowth following securement of the bone plate200to a bone. Taken together, the thread forming capability provided by the porous portion250positioned within the passageways220a,220b,220cand the advantageous bony ingrowth structure provided by the porous portion positioned on the majority of the lower surface218, the porous portion250provides desirable securement properties for the bone plate200.

The porous portion can comprise any suitable portion of the lower surface in a bone plate according to a particular embodiment, and a skilled artisan will be able to select a suitable portion, based on percentage of total surface area of the lower surface, for a bone plate according to a specific embodiment based on various considerations, including the anatomical location at which the bone plate is intended to be used. Examples of suitable percentages of total surface area of the lower surface that the porous portion comprises include, but are not limited to, at least about 50% of the total surface area of the lower surface, greater than 50% of the total surface area of the lower surface, between about 60% and about 90% of the total surface area of the lower surface, between about 70% and about 90% of the total surface area of the lower surface, between about 80% and about 90% of the total surface area of the lower surface, and between about 85% and about 90% of the total surface area of the lower surface.

While the bone plate illustrated inFIGS.1through3and the bone plate200illustrated inFIG.4are monolithic structures, bone plates according to some examples include multiple components. Indeed, hybrid bone plates, which include components of different materials, such as a metal component and a polymeric component, provide certain advantages, as described below.

FIG.5illustrates another example bone plate300. Bone plate300has a main body310and a support member390. Main body310defines a cavity360in which support member390is disposed.

Main body310has a first end312, a second end314, and a lengthwise axis301extending between the first end312and the second end314. The main body310has first316and second318opposing surfaces. The main body310and support member390cooperatively define a plurality of passageways320. Each passageway320a,320b,320cof the plurality of passageways320extends through the entire thickness of the bone plate300, from the first surface316to the second surface318. As such, each passageway320a,320b,320cprovides a through opening within which another component can be disposed, such as a bone screw useful in securing the bone plate300across a fracture in a bone as part of a fixation procedure.

The main body310and support member390cooperatively define a circumferential wall322a,322b,322cfor each passageway320a,320b,320cof the plurality of passageways320. Each circumferential wall322a,322b,322cbounds a respective passageway320a,320b,320c.

The main body310includes a non-porous portion330and a porous portion350. The non-porous portion330is a continuous portion of the main body310while the porous portion350comprises a plurality of discrete porous portions350a,350b,350c. Each circumferential wall322a,322b,322cis cooperatively formed by the non-porous portion330, one of the discrete porous portions350a,350b,350c, and the support member390. Each circumferential wall322a,322b,322cis recessed within a respective passageway320a,320b,320c, providing a countersink structure for a bone screw. Non-porous portion330of the main body310defines the upper portion324of each circumferential wall322c, while the support member390defines the lower portion326of the circumferential wall322c. Porous portion350cprovides an intermediate328cportion of the circumferential wall322a. In this example, lower surface318is cooperatively formed by the non-porous portion330of the main body310, the porous portions350a,350b,350cof the main body310, and the support member390.

In this example, the porous portion350provides boundaries for the cavity360of the main body310. This is particularly advantageous for bone plates in which the support member is formed by injection molding, as the porous portion350permits polymer to enter the passageways of the porous portion, enhancing fixation between the main body310and support member390. Furthermore, positioning of the porous portion350in the circumferential walls322a,322b,322calso provides the thread forming capability described above, providing additional advantage to this structural configuration.

Alternatively, as illustrated inFIG.6, the support member390′ can abut the porous portion350′ of the main body310, such that the polymer of the support member390′ does not extend into the passageways of the porous portion350′. Also alternatively, support member390′ can include a porous portion392′ as well. In this alternative example, porous portion392′ of the support member390′ forms a portion of lower surface318′, providing beneficial bony ingrowth properties for the bone plate300′. This structural configuration is considered particularly advantageous for bone plates in which the support member is formed by 3D printing, either onto the main body or simultaneously with the main body.

FIGS.7,8,9,10, and11illustrate another example bone plate400. The bone plate400is similar to the bone plate300illustrated inFIG.5and described above, except as detailed below. Thus, bone plate400has a main body410having a first end412, a second end414, and a lengthwise axis401extending between the first end412and the second end414. The main body410has first416and second418opposing surfaces, and defines a plurality of passageways420. Each passageway420a,420b,420c,420d,420e,420fof the plurality of passageways420extends through the entire thickness of the main body410, from the first surface416to the second surface418. As such, each passageway420a,420b,420c,420d,420e,420fprovides a through opening within which another component can be disposed, such as a bone screw useful in securing the bone plate400across a fracture in a bone as part of a fixation procedure. Main body410defines a cavity460in which support member490is disposed. Support member490defines a circumferential wall422a,422b,422c,422d,422e,422ffor each passageway420a,420b,420c,420d,420e,420fof the plurality of passageways420. Each circumferential wall422a,422b,422c,422d,422e,422fbounds a respective passageway420a,420b,420c,420d,420e,420f. As best illustrated inFIG.8, lower surface418is cooperatively formed by the main body410and the support member490. Upper surface416of main body410defines first430aand second432adepressions disposed adjacent passageway420a, first430band second432bdepressions disposed adjacent passageway420b, first430cand second432cdepressions disposed adjacent passageway420c, first430dand second432ddepressions disposed adjacent passageway420d, first430eand second432edepressions disposed adjacent passageway420e, and first430fand second432fdepressions disposed adjacent passageway420f.

In this embodiment, main body410defines an upper circumferential recess and a lower circumferential recess around each passageway420a,420b,420c,420d,420e,420fof the plurality of passageways420.FIGS.8and9illustrate the upper circumferential recess442cand the lower circumferential recess444cthat are disposed around passageway420c. In this example, an upper circumferential recess that is identical to upper circumferential recess442cand a lower circumferential recess that is identical to lower circumferential recess442dis disposed around each of the other passageways420a,420b,420d,420e,420fdefined by the main body410, but are not visible in the drawings.

In the illustrated example, the upper circumferential recess442cextends radially inward from the central axis of the passageway420cand generally in an upward direction toward the upper surface416of the main body410. The lower circumferential recess444calso extends radially inward from the central axis of the passageway420cand generally in an upward direction toward the upper surface416of the main body410. The lower circumferential recess444cextends further radially inward relative to the central axis of the passageway420cthan the upper circumferential recess442c.

Main body410defines first446cand second448ccircumferential projections that are disposed between the upper circumferential recess442cand lower circumferential recess444c. In this example, first and second projections that are identical to first446cand second448cprojections are disposed around each of the other passageways420a,420b,420d,420e,420fdefined by the main body410, but are not visible in the drawings. As best illustrated inFIGS.10and11, the inclusion and structural arrangement of first446cand second448cprojections accommodates the thread472of a bone screw470disposed through the passageway420cat multiple angles relative to the central axis of the passageway420c, such as a coaxial arrangement illustrated inFIG.10and an arrangement in which the bone screw470is disposed through the passageway420cat an angle to the central axis of the passageway420c, as illustrated inFIG.11. The inclusion and structural arrangement of first446cand second448cprojections also provides a structure against which the support member490can be urged during insertion of the bone screw470.

As indicated above, support member490defines a circumferential wall422a,422b,422c,422d,422e,422ffor each passageway420a,420b,420c,420d,420e,420fof the plurality of passageways420. As best illustrated inFIGS.8and9, the first446cand second448cprojections are disposed entirely within the support member490. This structural arrangement allows the thread472of a bone screw470to extend into the support member when the bone screw470is disposed through the passageway420c, as illustrated inFIGS.10and11. The material is the support member490is relatively softer than the material of the main body410, allowing the support member490to be disrupted upon entry of the thread472. This structural arrangement and composition of the circumferential wall422c, along with the presence and structural arrangement of the first446cand second448cprojections, provides for desirable engagement with the thread472of a bone screw470. In one particular example, the second projection disposed around each passageway comprises a circumferential thread itself, which is considered particularly advantageous at least because it further enhances the engagement of a bone screw passed through the passageway.

It is noted that, while not illustrated inFIGS.7,8,9,10, and11does not include a porous portion, bone plate400can include one or more porous portions, as described in detail above in connections with example bone plate100,200,300, and300′, for example.

The porous portion in a bone plate according to a particular embodiment can have any suitable dimensions, and a skilled artisan will be able to select appropriate dimensions for a porous portion in a bone plate according to a particular embodiment based on various considerations, including the function of the porous portion. For example, in embodiments in which the porous portion forms a portion of the circumferential wall bounding a screw passageway and is to deform in response to a screw being driven through the passageway, the inventors have determined that a porous portion having a thickness of between about 1 mm and 2 mm is suitable for a passageway having an inner diameter of 4 mm. In embodiments in which the porous portion forms a boundary for a cavity into which a support member is to be formed, such as by injection molding, the inventors have determined that a porous portion having a thickness of between about 0.5 mm and 1 mm is suitable.

Bone plates according to embodiments can be made from any material suitable for use in medical devices intended for orthopedic use, including use as a long-term implant. Examples of suitable materials include metals, metal alloys, and polymeric materials. Inclusion of a porous portion is critical to achieving the desired properties of the inventive bone plates. Accordingly, use of a material that enables formation of a porous portion using appropriate techniques is appropriate. Examples of suitable materials for which appropriate porous portions can be formed using conventional techniques, such as 3D printing, include, but are not limited to, Titanium, Magnesium, and other suitable materials. Examples of suitable metal alloys include stainless steel (316L), cobalt alloys, pure titanium, titanium alloys, magnesium alloys, molybdenum alloys, zirconium alloys, Ti6Al4V, 316 LVM, 1.4441Ti-13Nb-13Zr, Ti-12Mo-6Zr-2Fe, Ti-15Mo-5Zr-3Al, Ti15Mo, Ti-35Nb-7Zr-5Ta and Ti-29Nb-13Ta-4.6Zr Ti-6Al-7Nb and Ti-15Sn-4Nb-2Ta-0.2Pd Co—Cr—Mo alloys.

Non-metal materials are also considered suitable for use in bone plates according to embodiments, both as a main body component and, if included, as a support member component. Examples of suitable non-metal materials include polymeric materials, including plastic metals currently considered suitable for use in medical devices, carbon fiber, polyaryletherketone (PAEK), polyether ether ketone (PEEK), PEEK (90G, 450G, 12, 14), Polyamid, PA66, carbon fiber reinforced polyaryletherketone (CFR PAEK), polyethere ketone ketone (PEKK), carbon fiber reinforced polyether ketone ketone (CFR PEKK), carbon fiber reinforced polyether ether ketone (CFR PEEK), CFR PEEK (90G CA30, 90G CA20, 450G CA30, 450G CA20, 12 CF20, 12 CF30, 14 CF30, 14 CF20), Polyamid CFR, PA66 CFR, and any other materials considered suitable for a bone plate. The inventors have determined that, for embodiments in which the support member includes carbon fiber, it is considered advantageous to include carbon fiber in the material of the support member at an amount that represents a balance between the desirable strength carbon fiber provides and any offsets it contributes to the contourability of the bone plate due to the brittleness of the material. For plates that include a support member comprising carbon fiber reinforced polyether ether ketone (CFR PEEK), it is considered advantageous to include carbon fiber in PEEK at an amount that is less than 5% on a volume basis. It is also considered advantageous to include carbon fiber in PEEK at an amount that is less than 2.5% on a volume basis. It is also considered advantageous to include carbon fiber in PEEK at an amount that is less than 1% on a volume basis. It is also considered advantageous to include carbon fiber in PEEK at an amount that is less than 0.1% on a volume basis. It is also considered advantageous to include carbon fiber in PEEK at an amount that is less than 0.01% on a volume basis.

FIG.12illustrates an example bone plate system500. The bone plate system500includes a bone plate550according to an embodiment, such as the examples described and illustrated herein, and a plurality of bone screws560. The plurality of bone screws560includes a number of bone screws that is at least the same as the number of passageways in the bone plate550. Also, each bone screw of the plurality of bone screws560is adapted to be disposed in one of the passageways of the bone plate550. The bone plate550and the plurality of bone screws560can be disposed within or on a container510. One or more documents580containing instructions for using the bone plate550and plurality of bone screws560together can be included in the container510.

FIG.13is a flowchart representation of an example method of treatment600. The method600is suitable for treatment of a bone fracture. A first step610comprises placing a bone plate according to an embodiment across a fracture in a bone such that the lower surface of the bone plate is in contact with the bone. A second step612comprises driving a bone screw through a passageway of the bone plate such that the thread of the bone screw deforms the porous portion of the bone plate that comprises a portion of the circumferential wall of the passageway to form a mating thread in the circumferential wall. The second step can be repeated a suitable number of times until a bone screw is driven through each passageway of the bone plate and into the bone.

FIG.14is a flowchart representation of an example method of manufacturing a bone plate700. A first step710comprising 3D printing a main body having a porous portion and a non-porous portion such that the main body defines a plurality of passageways, each of which is bounded at least partially by the porous portion, and a cavity. A second step712comprises disposing a support member in the cavity. In one example, the second step712is accomplished by injection molding the support member into the cavity such that the polymeric material of the support member extends into the passageways of the porous portion of the main body that bounds each of the passageways. In another example, the second step712is accomplished by 3D printing the support member onto the main body such that the support member abuts the porous portion of the main body that bounds each of the passageways. In this example, the support member can be formed to include its own porous portion, such as a porous portion that forms a part of the lower surface of the bone plate that will contact the bone when placed across a fracture in the bone. In another example, the second step712is accomplished by 3D printing the support member simultaneously with the 3D printing of the main body. In this example, the support member can be formed to include its own porous portion, such as a porous portion that forms a part of the lower surface of the bone plate that will contact the bone when placed across a fracture in the bone.

FIG.15is a flowchart representation of another example method of manufacturing a bone plate800. A first step810comprises forming a bone plate precursor that includes a main body that defines a plurality of passageways, each of which is blocked by a sacrificial wall, and a cavity.FIG.16illustrates an example bone plate precursor900formed by performance of step810. The bone plate precursor900includes a plurality of passageways920, each passageway920a,920b,920c,920d,920e,920fof the plurality of passageways920is blocked by a sacrificial wall938a,938b,938c,938d,938e,938f. In one example, the first step810is accomplished by 3D printing the bone plate precursor900. In one particularly advantageous method, the first step is performed such that the bone plate precursor900is formed to have a pair of depressions930a,932a,930b,932b,930c,932c,930d,932d,930e,932e,930f,932fformed in an upper surface916of the main body910adjacent to each passageway920a,920b,920c,920d,920e,920fof the plurality of passageways920.

A second step812comprises disposing a support member in the cavity of the bone plate precursor to form a bone plate intermediate that includes a main body that defines a plurality of passageways, each of which is blocked by a sacrificial wall, and a cavity, and a support member disposed within the cavity such that the support member abuts each of the sacrificial walls.FIG.17illustrates an example bone plate intermediate1000formed by performance of step812. The bone plate intermediate1000includes a main body1010that defines a plurality of passageways (not visible in the figure), each passageway of which is blocked by a sacrificial wall (not visible in the figure), and a cavity1060, and a support member1090disposed within the cavity1060such that the support member1090abuts each of the sacrificial walls. In one example, the second step812is accomplished by injection molding the support member1090into the cavity1060of a bone plate precursor, such as bone plate precursor900. In another example, the second step812is accomplished by 3D printing the support member onto the bone plate precursor. In another example, the second step812is accomplished by 3D printing the bone plate precursor simultaneously with the 3D printing of the support member.

A third step814comprises removing the sacrificial wall associated with each passageway of the plurality of passageways in the bone plate intermediate to form final passageways that extend through the main body and the support member. In one example, this step814is accomplished by drilling through the sacrificial wall and the support member in a bone plate intermediate, such as bone plate intermediate1000.FIG.18illustrates performance of particularly advantageous example of this step814. In this example, drilling is performed on each passageway1020a, sequentially or concurrently, until a portion of the drill head1099contacts a pair of depressions1030a,1032aformed in an upper surface1016of the main body1010of a bone plate intermediate1000adjacent to each passageway1020aof the plurality of passageways. Step814is completed once all sacrificial walls have been removed, providing a finished bone plate. Additional processing steps can be included, such as application of coatings, polishing, and the like.

The foregoing detailed description refers to various example bone plates, bone plate systems, methods of treatment, and methods of manufacturing a bone plate. The description and appended drawings illustrating the described bone plates, bone plate systems, methods of treatment, and methods of manufacturing a bone plate are intended only to provide examples and not to limit the scope of the claims in any manner.