Tibial trialing assembly and method of trialing a tibial implant
A trialing assembly for use during knee replacement procedures to determine size and position of a tibial plate implant as well as the size and thickness of the articular surface prior to implantation of the implant. The trialing assembly includes a broaching plate having a tibia engaging bottom surface adapted for placement atop a tibia and an opposite top surface, the bottom and top surfaces extending between an anterior edge and a posterior edge of the broaching plate. The broaching plate includes an anterior rail and a posterior rail protruding superiorly from the top surface and extending along the anterior and posterior edges, respectively. A trialing plate is configured to removably fit atop the broaching plate between the anterior and posterior rails. The trialing plate includes an engagement member extending from a superior surface of the trialing plate and adapted to engage with an articular surface provisional.
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This application claims the benefit of priority under 35 U.S.C. §119(e) to provisional application Ser. No. 60/653,902, filed in the name of Kristina J. Morley et al. on Feb. 17, 2005 and entitled TIBIAL TRIALING ASSEMBLY AND METHOD OF TRIALING A TIBIAL IMPLANT.
BACKGROUNDThe present invention relates to trialing devices used during knee replacement procedures to size and prepare a resected tibia for receiving a tibial implant and to evaluate the stability and kinematic performance of the articular surface provisional prior to implantation of the tibial implant.
Generally, the knee is the joint between the femur and the tibia. The knee joint is formed of a pair of condyles located at the distal portion of the femur, a tibial plateau located at the proximal end of the tibia and shaped to mate with the pair of condyles, and a pair of menisci positioned between the tibial plateau and the condyles. The femur and the tibia are connected by ligaments, which provide stability to the knee. Such ligaments include the posterior cruciate ligament (PCL), the lateral collateral ligament, the medial collateral ligament, and the anterior cruciate ligament. Significant disease of, or trauma to, the knee may warrant replacement of the knee with a prosthetic knee (knee implant).
A prosthetic total knee joint generally includes a femoral component and a tibial component. The tibial component typically includes a tibial tray or plate and a prosthetic bearing insert. The tibial tray often includes a stem, which extends from the bottom of the tray and is sized for insertion into the tibia. In some knee implants, the bearing insert may be fixed to the tibial tray such that the bearing insert is immobile relative to the tibial tray. These knee implant designs are often referred to as “fixed bearing” designs. In other knee implants, the bearing insert is movably fixed to the tibial tray thereby allowing the bearing insert to move relative to the tibial tray. These knee implant designs are typically referred to as “mobile bearing” designs.
During mobile bearing knee replacement surgery, the surgeon first prepares the proximal end of the tibia by resecting the proximal tibia or, in the case of revision, removing the damaged tibial components prior to resecting the proximal tibia. After the tibia is prepared, a tibial sizing plate is aligned and placed on the resected tibia, and checked for size. After the proper sizing plate is selected and the optimal location is determined, the sizing plate is fixed in position on the resected tibia by inserting pins through the sizing plate and into the resected tibia. The pins generally have cap heads that remain extended above the surface of the sizing plate so that the pins can be extracted upon completion of the trial. Next, the surgeon selects an articular surface provisional, which is modeled in shape and design after the bearing insert of the tibial component that the surgeon proposes to implant. The surface provisional is then engaged with the sizing plate. With the articular surface provisional in place, the surgeon then performs trialing procedures to test the fit and function of the articular surface provisional. Such trialing procedures may include measuring the flexion and extension gaps, and conducting range of motion tests, during which the anterior/posterior and medial/lateral stability and movement may be tested. These trialing procedures help the surgeon determine the proper sized bearing insert. The surgeon may repeat the trialing procedures with different sized provisionals until the desired results are achieved.
Next, the surgeon removes the pins and the sizing plate. A broaching plate is then positioned and carefully aligned on the resected tibia such that pin holes in the broaching plate are aligned with the pin holes created in the tibia by the mounting of the sizing plate. Once aligned, the broaching plate is pinned in place. With the broaching plate in place, a drill/broach guide is engaged with the upper surface of the broaching plate and the proximal tibia is drilled and/or broached to accommodate the tibial stem of the tibial tray.
There is a need for a tibial trialing device that simplifies and minimizes the steps of knee replacement surgery.
SUMMARYThe present invention provides a trialing assembly for use during knee replacement procedures to prepare and size a resected tibia for receiving a tibial implant and to evaluate the stability and kinematic performance of the articular surface provisional prior to implantation of the tibial implant. In one form, the trialing assembly includes a broaching plate having an outer periphery substantially conforming to the resected tibia. The broaching plate includes a bottom surface adapted for placement atop the resected tibia and an opposite top surface. The bottom and top surfaces extend substantially between the outer periphery. The broaching plate includes a plurality of alignment rails protruding superiorly from the top surface and extending along at least a portion of the outer periphery. A trialing plate is configured to removably fit atop the broaching plate between the plurality of alignment rails. The trialing plate has a superior surface and a boss extending superiorly from the superior surface. The boss is adapted to engage with an articular surface provisional.
In another form, the trialing assembly includes a broaching plate having an outer periphery, a bottom surface adapted for placement atop the resected tibia and an opposite top surface. The bottom and top surfaces extend substantially between the outer periphery. A trialing plate is removably disposed atop the broaching plate and overlies substantially all of the top surface. The trialing plate includes a boss extending superiorly from the superior surface of the trialing plate. The boss is adapted to engage with the articular surface provisional.
BRIEF DESCRIPTION OF THE DRAWINGSThe above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. Although the exemplification set out herein illustrates embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed.
DETAILED DESCRIPTIONThe present invention will now be described with reference to the attached figures. The description below may include references to the following terms: anterior (at or near the front of the body, as opposed to the back of the body); posterior (at or near the back of the body, as opposed to the front of the body); lateral (at or near the side of the body, farther from the midsagittal plane, as opposed to medial); medial (at or near the middle of the body, at or near the midsagittal plane, as opposed to lateral); proximal (toward the beginning, at or near the head of the body, as opposed to distal) and distal (further from the beginning, at or near the foot of the body, as opposed to proximal).
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Broaching plate 12 may be formed of any surgical grade rigid material. For example, broaching plate 12 may be formed of cobalt chromium, stainless steel, titanium, and/or alloys thereof. Broaching plate 12 may be made available in various sizes to accommodate various sized tibias.
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Trialing plate 14 includes articular surface provisional engagement member or boss 48 protruding superiorly from superior surface 42. As discussed below, boss 48 has an elliptically shaped cross-section and is configured to engage with an articular surface provisional. Alternatively, engagement member or boss 48 may have a variety of shapes and sizes to accommodate engagement with various designs of surface provisionals. Furthermore, trialing plate may comprise more than one articular surface provisional engagement member or boss. Central bore 50 extends in the superior/inferior direction through boss 48 and trialing plate 14. Bore 50 is adapted to allow the passage of fastener 54 (
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When trialing plate 14 is properly positioned atop broaching plate 12, trialing plate 14 overlies substantially all of top surface 24 of broaching plate 12 to provide a smooth, un-interrupted surface on which the surface provisional may articulate. Once trialing plate 14 is flushly positioned atop broaching plate 12, anterior and posterior rails 26, 28 cooperate to prevent the movement of trialing plate 14 along the plane of top surface 24 in the medial/lateral and anterior/posterior directions. Furthermore, as illustrated in
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Although the embodiments discussed above show a pair of opposing anterior and posterior rails, alignment rails could, alternatively, include any number of rails positioned at any location along the outer periphery. For instance, the alignment rails may include two opposing rails, one located at the medial edge of the outer periphery and the other at the lateral edge of the outer periphery. In another example, the alignment rails may include three rails spaced apart along the outer periphery. In fact, it is possible to have a single rail extending along a portion of the periphery enough to limit the movement of the trialing plate when mounted atop the broaching plate. Furthermore, the alignment rail or rails need not be positioned on the periphery of the plate. It is also possible to have no alignment rails, instead using alignment members, such as pegs extending from one of the trialing plate or broaching plate and mating with alignment holes in the other of the trialing plate and broaching plate. Alternatively, the pin heads used to fix the broaching plate to the tibia could be used in conjunction with the head receiving openings in the trialing plate to align the trialing plate on the broaching plate. It should also be noted that the alignment rails could be alternatively disposed on the inferior surface of the trialing plate and could engage the outer periphery of the broaching plate such that broaching plate positioned between the alignment rails of the trialing plate.
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Also, as shown in the embodiments described above, superior surface of the trialing plate is level with the superior surfaces of the rails. Alternatively, superior surface 42 of trialing plate 14 may be proud, or raised, with respect to superior surfaces 26a and 28a of anterior and posterior rails 26, 28 to provide a smooth surface and to prevent rails 26, 28 from interfering with the movement of the articular surface provisional.
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Trialing plate 414 is adapted to also mate with broaching plate 512, shown in
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Broaching plate 512 and trialing plate 414 are used in a manner similar to that described above with respect to broaching plate 12 and trialing plate 14. Broaching plate 512 is secured to the resected surface of the tibia by inserting pins through pin holes 530. Trialing plate 414 is placed over broaching plate 512 and is positioned between rails 526, 528 such that the heads of the pins are received in head receiving openings 446 of trialing plate 414 and tab 453 is positioned in notch 527. When so positioned, superior surface 442 of trialing plate 414 is level with superior surfaces 526a, 528a of anterior and posterior rails 526, 528. The assembly of broaching plate 512 and trialing plate 414 may be used to trial an articular surface provisional in a manner similar to that described above with respect to tibial trialing assembly 10.
Although the embodiments shown in the drawings and discussed above are used in the sizing and trialing of knee implants, it is contemplated that the present invention could be adapted for use in sizing and trialing other implants, including elbows and ankles.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
Claims
1. A trialing assembly for use during a knee replacement procedure to size and prepare a resected tibia for receiving a tibial implant and to trial an articular surface provisional, said trialing assembly comprising:
- a broaching plate having an outer periphery, said broaching plate including a bottom surface adapted for placement atop the resected tibia and an opposite top surface, and a plurality of alignment rails protruding from said top surface, each alignment rail extending adjacent at least a portion of said outer periphery; and
- a trialing plate removably positionable atop said broaching plate between said plurality of alignment rails, said trialing plate having a superior surface and an articular surface provisional engagement member extending superiorly from said superior surface.
2. The trialing assembly of claim 1 wherein said plurality of alignment rails includes an anterior rail extending adjacent an anterior portion of said outer periphery and a posterior rail extending adjacent a posterior portion of said outer periphery.
3. The trialing assembly of claim 1 wherein said trialing plate overlies substantially all of said top surface of said broaching plate when said trialing plate is positioned atop said broaching plate.
4. The trialing assembly of claim 1 wherein said broaching plate includes at least one fastener hole configured for receipt of a fastener therethrough for engagement with the resected tibia.
5. The trialing assembly of claim 4 wherein said fastener includes a head, said head engaging, and extending superiorly from, said top surface of said broaching plate when said fastener is received within said at least one fastener hole, said trialing plate including at least one opening, said at least one opening aligned with said at least one fastener hole and receiving said fastener head when said trialing plate is positioned atop said broaching plate.
6. The trialing assembly of claim 1 wherein said engagement member includes a trialing plate removal element.
7. The trialing assembly of claim 1 wherein each of said plurality of alignment rails includes an upper surface, said superior surface of said trialing plate being substantially level with said upper surface of each of said plurality of alignment rails when said trialing plate is positioned atop said broaching plate.
8. A trialing assembly for trialing an articular surface provisional prior to implantation of the tibial implant on a resected tibia, the trialing assembly comprising:
- a broaching plate having an outer periphery surrounding a bottom surface adapted for placement atop the resected tibia and an opposite top surface; and
- a trialing plate removably disposed atop said broaching plate and overlying substantially all of said top surface, said trialing plate including an articular surface provisional engagement member extending superiorly from a superior surface of said trialing plate.
9. The trialing assembly of claim 8 wherein said member includes a trialing plate removal element.
10. The trialing assembly of claim 9 wherein said member includes an outer wall, and said trialing plate removal element includes a groove within said outer wall.
11. The trialing assembly of claim 8 wherein said broaching plate includes at least one alignment rail protruding superiorly from said top surface.
12. The trialing assembly of claim 11 wherein said at least one alignment rail includes an anterior rail extending along an anterior portion of said outer periphery and a posterior rail extending along a posterior portion of said outer periphery.
13. The trialing assembly of claim 8 further comprising a provisional base plate having a base plate periphery surrounding an upper surface and an opposite lower surface, said lower surface adapted for placement atop the resected tibia, said provisional base plate having a stem projecting from said lower surface and adapted for insertion into the resected tibia, said base plate having at least one alignment rail projecting from said upper surface, said trialing plate removably positionable atop said provisional base plate and engagable with said at least one alignment rail to prevent movement of said trialing plate relative said base plate along a plane of the upper surface of said base plate.
14. The trialing assembly of claim 1 wherein one of said plurality of alignment rails includes a notch and said trialing plate includes a tab, said tab configured to be received in said notch when said trialing plate is positioned atop said broaching plate.
15. The trialing assembly of claim 8 wherein said trialing plate includes an inferior surface opposite said superior surface, and wherein one of said inferior surface of said trialing plate and said top surface of said broaching plate includes at least one alignment member extending outwardly therefrom, and the other of said inferior surface of said trialing plate and said top surface of said broaching plate includes at least one alignment member opening, said at least one alignment member opening receiving said at least one alignment member.
16. The trialing assembly of claim 8 wherein said broaching plate includes at least one fastener hole and said trialing plate includes a head receiving opening aligned with each of said at least one fastener holes.
17. The trialing assembly of claim 8 wherein said trialing plate includes a central bore extending through said boss and said trialing plate and configured to receive a fastener therethrough to fix said trialing plate to the resected tibia.
18. The trialing assembly of claim 8 wherein each of said broaching plate and trialing plate includes a plurality of augment holes each adapted to mate with an augment provisional.
19. The trialing assembly of claim 8 wherein one of said trialing plate and said broaching plate includes at least one alignment rail, said at least one alignment rail engaging the other of said trialing plate and said broaching plate to restrict movement of said trialing plate relative said broaching plate along a plane of said top surface.
20. A trialing assembly for trialing an articular surface provisional, the trialing assembly comprising:
- a broaching plate having a bottom surface adapted for placement atop the resected tibia and an opposite top surface; and
- a trialing plate removably disposed atop said broaching plate and overlying substantially all of said top surface, said trialing plate having an inferior surface adapted for placement atop said top surface and an opposite superior surface, said trialing plate including an engagement member extending superiorly from said superior surface, said engagement member adapted to engage with said surface provisional, wherein one of said broaching plate and said trialing plate including at least one peg opening, the other of said broaching plate and said trialing plate includes at least one peg extending therefrom, said at least one peg received within said at least one peg opening.
Type: Application
Filed: Feb 7, 2006
Publication Date: Aug 17, 2006
Applicant:
Inventors: Kristina Straszheim-Morley (Warsaw, IN), Dwight Todd (Columbia City, IN), Brian Byrd (North Webster, IN), Scott Lazar (Cromwell, IN)
Application Number: 11/348,990
International Classification: A61B 17/58 (20060101);