US20160143663A1

Movatterモバイル変換

Info

Publication number: US20160143663A1
Application number: US14/949,185
Authority: US
Inventors: Emil Schemitsch; Michael McKee
Original assignee: Stryker European Holdings I LLC
Current assignee: Stryker European Holdings I LLC
Priority date: 2014-11-24
Filing date: 2015-11-23
Publication date: 2016-05-26
Also published as: US20200237407A1; EP3023067A1; US11457954B2; EP3023067B1

Abstract

A bone plate assembly and method of utilizing same are disclosed. The assembly includes at least two plates affixed to the bone in two different locations. One of the plates includes a porous bone in-growth surface, and may be entirely porous. The assembly may further include at least one bone screw and cable for affixing the plates to the bone. In the method of use, the plates may be affixed by the screws and/or cables and the plate including the porous surface may be left in place after bone is allowed to grow therein.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. provisional patent application No. 62/083,491 filed Nov. 24, 2014, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention pertains to orthopedic bone plates, and in particular, orthopedic bone plates with bone in-growth capabilities.

A common method utilized in repairing fractures of bones includes affixing bone plates to the bone with screws. Generally, the plates are oriented so that portions thereof are placed on either side of the fracture and screws are placed through at least one bone screw hole of each bone plate portion. Depending upon the particular anatomical area of the fracture, different plate designs exist. For instance, plates designed for use on the distal and proximal portions of long bones such as the femur or tibia may include a shaft and a head, with screw holes extending through each.

One issue that is often faced by surgeons is the tendency of bone screws inserted through bone plates to back out of the bone plate and/or bone after implantation. Many different bone plate configurations have been designed to prevent such occurrences. For instance, it has been known for some time to thread portions of the bone screws to the plate holes to prevent the unwanted back out. Likewise, different secondary fixation elements (e.g., caps or the like) have been utilized in prior art plates.

Another issue faced by surgeons is often encountered in repairing perio-prosthetic fractures, which are fractures that occur around an implanted prosthesis (e.g., those utilized in total hip, total knee, or total shoulder arthroplasty). Because of the already implanted prosthesis, and the tendency of the fractures to be somewhat complicated, perio-prosthetic fractures are typically complex and difficult to treat with conventional methods. For instance, in placing screws through a bone plate, it can be difficult for a surgeon to both navigate around the already implanted prosthesis and capture each of the bone fragments of the fracture.

Therefore, there exists a need for a bone plate and cabling system capable of treating fractures such as perio-prosthetic fractures, as well as providing an alternative to bone screws which have a tendency to back out.

BRIEF SUMMARY OF THE INVENTION

A first aspect of the present invention is a bone plate assembly for fixing a fracture of a bone. The bone plate assembly includes a first bone plate attached to the bone and a second bone plate attached to the bone. The second bone plate includes a porous bone in-growth surface.

In one embodiment of the first aspect the first and second bone plates are attached to opposite sides of the bone. The assembly may further include at least one screw extending through the first bone plate and into the bone and at least one cable extending around the first and second plates. The at least one screw may be cannulated and the at least one cable may extend therethrough. The first plate may include a channel or slot and the at least one cable may extend through the channel or slot. The second bone plate may be entirely porous, or the bone in-growth surface may be attached to a solid portion. The first and second plates may be metallic, polymeric or any other suitable material.

A second aspect of the present invention is a method of fixing a fracture of a bone including the steps of attaching a first plate to the bone so that the first plate spans at least a portion of the fracture, attaching a second plate to the bone so that the second plate spans at least a portion of the fracture and allowing bone to grow into at least a portion of the second plate.

Other embodiments of the second aspect may further include the step of removing the first plate subsequent to the allowing step. The second plate may include a porous bone in-growth surface. The attaching the first plate step may include inserting at least one bone screw through the first plate and into the bone. The attaching steps may include wrapping at least one cable around the first and second plates. The cable may be placed through the at least one screw, a channel or slot or a cable plug.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the subject matter of the present invention and of the various advantages thereof can be realized by reference of the following detailed description in which references made to the accompanying drawings in which:

FIG. 1 is a perspective view of a bone plate and cabling system according to one embodiment of the present invention attached to a femur.

FIG. 2 is another perspective view of the bone plate and cabling construct ofFIG. 1 focusing on a different plate of the construct.

FIG. 3 is a cross sectional view taken along line D-D ofFIG. 2.

FIG. 4 is a cross sectional view taken along line B-B ofFIG. 1.

DETAILED DESCRIPTION

The present invention addresses both above-noted needs, by providing a bone plate and cabling system that does not rely solely upon bone screws inserted through the plate. Rather, the present invention makes use of porous plates that can be initially affixed via a novel cabling system and thereafter allow for bone ingrowth into the plates to support the construct. Although the porous bone plates disclosed herein are described as being constructed of porous metal foam, it is contemplated that the bone plates may be of many different types of materials, including, but limited, ceramics, plastics or the like. It is also contemplated to utilize the porous bone plates of the present invention in conjunction with more standard bone plates known in the art.

FIGS. 1 and 2 depict afemur1 with a bone plate andcabling system10 attached thereto.System10, as shown, includes afirst bone plate12 and a second bone plate14 (best shown inFIG. 2).Bone plate12 is standard bone with a plurality ofbone plate holes16 that are shown both as exhibiting circular and elongate forms. Of course, the holes may exhibit any shape or construct known in the art, including, without limitation, oblong compression holes, threaded holes and holes that include deformable structures. Likewise, any number of holes may be provided onplate12 in connection with the present invention. Additionally,plate12 includes at least one channel orslot18 that is sized and shaped to accept and retain a cable of the type discussed more fully below. As shown,plate12 is designed for use in connection with a distal femur, but can exhibit many different configurations depending upon the bone that requires repair.

On the other hand,bone plate14 is shown constructed of porous material, with no holes formed therethrough. The porous material is preferably designed to allow for bone to grow directly intoplate14 after implantation. Although shown as consisting largely of the porous material,plate14 can be only partially formed of the porous material. Specifically, in other embodiments,bone plate14 may include an underside surface that is of a porous construction, so that when placed against the bone it can facilitate bone in-growth from the affected bone into the plate. In such a case, the remainder of the plate can be of a more solid construction.

As shown, the porous metallic construction ofbone plate14 was created utilizing a laser remelting process (“LRM”). In fact, it is contemplated to form the entirety ofplate14 with such a process, including any solid portions that may be included therein. Those solid portions could alternatively be formed through more conventional processes (e.g., molding, forging, etc. . . . ) and a porous lower or bone contacting surface can be later affixed thereto via a process like LRM. Without limitation, the LRM processes disclosed in U.S. Pat. Nos. 7,537,664 and 8,147,861; U.S. Patent Application Publications Nos. 2006/0147332, 2007/0142914, 2008/0004709; and U.S. patent application Ser. Nos. 13/441,154 and 13/618,218, the disclosures of which are hereby incorporated by reference herein, can be utilized. It is also contemplated to form any porous surface via a laser etching procedure.

Also depicted inFIGS. 1 and 2 is a cabling system that includes plurality of cables20a-dand at least onecannulated screw22. As shown, the cables may be situated so as to extend throughscrew22 and aroundplate12 and the femur (cable20a), around bothplates12 and14 (

cables

20band20d) and through channel orslot18 and around plate14 (cable20c). Of course, other configurations are also contemplated depending upon the bone being repaired and the plates being utilized.

Screw

22 not only allows for the fixation ofplate12 to the bone, but also its cannulation allows for passage ofcable20atherethrough so that the cable only needs to wrap around the affected bone on one side thereof. This is further shown in the cross sectional view ofFIG. 3. Althoughscrew22 is shown as a one piece screw, it is contemplated that the screw can include a modular head or the like. In addition, it is contemplated for one or more of plate holes16 to be designed such that they are not only sized and shaped to receive the screws, but also allow polyaxial movement of the screws with respect to the plate. Above-mentioned channel orslot18 is sized, shaped and oriented to receive and guide a cable placed therethrough. The channel orslot18 can be of an open or closed design, the latter of which entirely retains the cable therein. Of course, although only a single channel or slot is shown included onplate12, any number of them may be provided on a given plate.

In use, a surgeon will placeplate12 against an affected bone (such as femur1), so that different portions of the plate span any fracture(s) in the bone. Thereafter screws, such asscrews22, may be placed through the plate and into the bone. Cables20a-dmay then be applied to the construct andplate14 may be introduced to the opposite side of the bone fromplate12. It is also contemplated to placeplate14 in other positions than directly opposite to plate12 (e.g., to the side of the bone). Upon tightening of the cables,

plates

12 and14 are fixed in position.

In the case of a peri-prosthetic fracture, care must be taken as to the placement of any screws so as not to interfere with the already implanted prosthesis. However, it is possible through the use of the plates, screws and cables of the present invention properly stabilize the fracture without the need for screws extending into each bone fragment. Rather, less screws can be utilized when utilizing cables26. The cables act to stabilize the fracture, much like multiple screws would in the case of a standard bone plate use. This is especially true in the context of peri-prosthetic fractures, where the amount of bone screws that can be utilized is limited.

In situations in which

bone plates

12 and14 are utilized, the use of two plates allows for a stable fixation of the bone fracture viaplate12, while bone is allowed to grow intoplate14. After proper bone growth, a surgeon may elect to removebone plate12 from the fracture site, thereby leaving what is effectively become a continuous bone/plate14 construct. It is, of course, contemplated that the plates may be placed on many different portions of the bone, as well as to leave both plates in place for an extended period of time. Additionally, it is contemplated to utilize only plate14 with one or more cables at least initially holding it in place. After proper bone growth intoplate14, the cables may be removed. It is to be understood thatplate14 could also be designed to work in conjunction with screws, likescrew22, or to include one or more channels or slots like are discussed above. Any holes provided in

plates

12 or14 could also accept a cable plug, which can provide an additional mechanism for associating the plate with a cable. For instance, it is envisioned to utilize with

plates

12 or 14 any of the cables plugs disclosed in U.S. Pat. No. 8,142,434, U.S. Patent Application Publication No. 2014/0107710 and U.S. Provisional Application No. 62/035,074, the disclosures of which are hereby incorporated by reference herein.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A bone plate assembly for fixing a fracture of a bone comprising:

a first bone plate attached to the bone; and

a second bone plate attached to the bone, the second bone plate including a porous bone in-growth surface.

2. The bone plate assembly ofclaim 1, wherein the first and second bone plates are attached to opposite sides of the bone.

3. The bone plate assembly ofclaim 1, further comprising at least one screw extending through the first bone plate and into the bone and at least one cable extending around the first and second plates.

4. The bone plate assembly ofclaim 3, wherein the at least one screw is cannulated and the at least one cable extends therethrough.

5. The bone plate assembly ofclaim 3, wherein the first plate includes a channel or slot and the at least one cable extends through the channel or slot.

6. The bone plate assembly ofclaim 1, wherein the second bone plate is entirely porous.

7. The bone plate assembly ofclaim 1, wherein the bone in-growth surface is attached to a solid portion.

8. The bone plate assembly ofclaim 1, wherein the first and second plates are metallic.

9. A method of fixing a fracture of a bone comprising the steps of:

attaching a first plate to the bone so that the first plate spans at least a portion of the fracture;

attaching a second plate to the bone so that the second plate spans at least a portion of the fracture; and

allowing bone to grow into at least a portion of the second plate.

10. The method ofclaim 9, further comprising the step of removing the first plate subsequent to the allowing step.

11. The method ofclaim 9, wherein the second plate includes a porous bone in-growth surface.

12. The method ofclaim 9, wherein the attaching the first plate step includes inserting at least one bone screw through the first plate and into the bone.

13. The method ofclaim 12, wherein the attaching steps include wrapping at least one cable around the first and second plates.

14. The method ofclaim 13, wherein the cable is placed through the at least one screw.

15. The method ofclaim 13, wherein the cable is placed through a channel or slot formed in the first plate.

16. A bone plate assembly for fixing a fracture of a bone comprising:

a first bone plate attached to the bone;

a second bone plate attached to an opposite side of the bone, the second bone plate being formed entirely of a porous bone in-growth material; and

at least one screw extending through the first bone plate and into the bone and at least one cable extending around the first and second plates.

17. The bone plate assembly ofclaim 16, wherein the first plate includes a channel or slot and the at least one cable extends through the channel or slot.

18. The bone plate assembly ofclaim 16, wherein the first and second plates are metallic.

19. The bone plate assembly ofclaim 16, further comprising a plurality of screws and cables.

20. The bone plate assembly ofclaim 16, wherein the first and second bone plates are formed of different materials.