KNEE PROSTHESIS
A knee joint prosthesis assembly including a femoral component and a unitary tibial component. The femoral component includes a first condyle and a second condyle. The unitary tibial component includes an engaging structure configured to rigidly secure a stationary bearing thereto. The stationary bearing is configured to articulate with the first condyle. The unitary tibial component further includes a planar tibial bearing surface configured to slidably support a mobile bearing thereon. The mobile bearing includes an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle.
This application is a continuation of U.S. patent application Ser. No. 13/609,389 filed Sep. 11, 2012, which is a continuation-in-part of U.S. patent application Ser. No. 12/788,961 filed on May 27, 2010, which claims the benefit and priority of U.S. Patent Application No. 61/181,938 filed May 28, 2009. The entire disclosure of the above applications is incorporated herein by reference.
FIELDThe present disclosure relates to a knee joint prosthesis including a tibial tray component having independent and selectively attachable bearings including fixed and mobile bearings that can be secured to medial and lateral sides of the tibial tray according to the needs of a particular patient.
BACKGROUNDThis section provides background information related to the present disclosure which is not necessarily prior art.
A knee joint prosthesis can generally comprise a femoral component and a tibial component. The femoral component and the tibial component can be designed to be surgically attached to the distal end of the femur and the proximal end of the tibia, respectively. The femoral component can further be designed to cooperate with the tibial component in simulating the articulating motion of an anatomical knee joint. In many examples, the tibial component can further include a bearing component that includes articulation surfaces on the medial and lateral side for cooperating with a medial and lateral condyle portion of the femoral component. In some examples, the bearing component can be fixed relative to the tibial component. In other examples, the bearing component can be a mobile bearing component that has at least a portion that can move relative to the tibial component during articulation of the femoral component.
SUMMARYThis section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
The present teachings provide for a knee joint prosthesis assembly including a femoral component and a unitary tibial component. The femoral component includes a first condyle and a second condyle. The unitary tibial component includes an engaging structure configured to rigidly secure a stationary bearing thereto. The stationary bearing is configured to articulate with the first condyle. The unitary tibial component further includes a planar tibial bearing surface configured to slidably support a mobile bearing thereon. The mobile bearing includes an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle.
The present teachings further provide for a knee joint prosthesis assembly including a femoral component and a unitary tibial component. The femoral component includes a first condyle and a second condyle connected by a patellar track portion. The femoral component defines an opening between the first condyle and the second condyle. The unitary tibial component includes an engaging structure configured to rigidly secure a stationary bearing thereto. The stationary bearing is configured to articulate with the first condyle. The planar tibial bearing surface is configured to slidably support a mobile bearing thereon. The mobile bearing includes an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle. A rail extends in an anterior-posterior direction and is configured to restrict the mobile bearing to anterior-posterior movement.
The present teachings also provide for a knee joint prosthesis assembly including a femoral component and a unitary tibial component. The femoral component includes a first condyle and a second condyle connected by a patellar track portion. The femoral component defines an opening between the first condyle and the second condyle. The unitary tibial component includes a medial portion, a lateral portion, and a slot defined between the medial portion and the lateral portion. The engaging structure extends superiorly from one of the medial portion or the lateral portion. The engaging structure is configured to rigidly secure a stationary bearing thereto, which is configured to articulate with the first condyle. A planar tibial bearing surface is at the other of the medial portion or the lateral portion, and is configured to slidably support a mobile bearing thereon. The mobile bearing includes an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle. A rail is between the planar tibial bearing surface and the engaging structure. The rail extends in an anterior-posterior direction and is configured to restrict the mobile bearing to anterior-posterior movement.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTIONExample embodiments will now be described more fully with reference to the accompanying drawings.
With initial reference to
The respective components of the knee prosthesis assembly 10 can be patient specific, such that each component can be constructed for optimal features for a given patient. For example, the bone interface margins of the femoral component 12 and tibial tray 14 can be patient specific for optimized bone coverage. In addition, the overall size, such as anterior-posterior dimensions and bone cut geometry can be determined and used for manufacturing the components of the knee prosthesis assembly 10. Moreover, some articulation features can be determined and used as criteria for forming the components of the knee prosthesis assembly 10. In sum, each of the components of the knee prosthesis assembly 10 can be a patient-specific implant, a semi-custom implant or an off-the-shelf or standard production implant. A custom-made implant is a patient-specific, one-of-a-kind implant specifically made for a particular patient, and consequently there is no inventory associated with such implant. Standard or off-the shelf implants are available and stocked in a number of sizes, typically six or more, and a number of configurations or types, including bilateral or unilateral implants, constrained, semi-constrained, mobile, etc. Because of the variety of sizes and configurations that are kept in stock to be accommodated by different patients, a large inventory of standard implants is created, and several molds for each type and size of implant may be used. Semi-custom implants can provide an intermediate solution between custom-made and off-the-shelf implants. Semi-custom implants reduce the size of inventory and molds required for production, while allowing some degree of patient-specific customization. Additional description of patient-specific implants and semi-custom implants and their implementations may be found in copending patent application Ser. No. 12/103,824, filed Apr. 16, 2008 and entitled: Method and Apparatus for Manufacturing an Implant, the disclosure of which is hereby incorporated by reference.
With additional reference to
The femoral component 12 can include a bone contacting or inferior surface 34 (
With reference now to
With reference to
With reference to
During use, the medial and lateral condyle portions 20 and 22 of the femoral component 12 can articulate on the first and second bearing surfaces 102 and 120 of the respective medial floating bearing 16 and lateral fixed bearing 18. As can be appreciated, the lateral fixed bearing 18 is static relative to the tibial tray 14 during articulation of the femoral component 12. The medial floating bearing 16 is free to slide along the highly polished tibial bearing surface 70 of the medial portion 60 of the tibial tray 14. The medial floating bearing 16 is bound on an inboard side by the rail 72.
While the embodiment shown in the figures includes a floating bearing provided on a medial side and a fixed bearing provided on a lateral side, the location of these bearings can be swapped. Similarly, both of the medial and lateral sides can be formed with floating bearings or fixed bearings. Turning now to
With reference now to
The femoral component 12 can be generally formed similar to the femoral component 12 described in detail above. Again, the medial condyle portion 20 can have a spherical, convex articulation surface that can cooperate with the mobile bearing components 316 as will be described herein. It is appreciated that a similar spherical, convex articulation surface can be provided on the lateral condyle portion 22 in the event that a mobile bearing component is desired on the lateral portion 322 of the tibial tray 314.
The mobile bearing component 316 can generally include a fixed portion 330 and a mobile bearing portion 332 (
The mobile bearing portion 332 can have an outer perimeter surface 350 that substantially matches a profile of the surrounding wall 336, however, is reduced in size so as to be stepped inwardly relative to the surrounding wall 336 (see also
The fixed bearing component 318 can generally include a superior surface 360 that substantially conforms to and provides a surface contact with the profile of the lateral condyle portion 22 of the femoral component 12. A channel 362 can be formed along an anterior inferior surface 364 and that generally tapers anteriorly. A groove 368 can be formed around a posterior edge of the fixed bearing component 318. The fixed bearing component 318 can have an inner wall 369 that cooperates with the U-shaped profile of the tibial tray 314 to accommodate a host or reconstructed ACL.
The tibial tray 314 can generally include a locating tab 370 formed on an anterior edge of the medial portion 320 and a locating tab 372 formed on an anterior edge of the lateral portion 322. A slot 374 can be defined through the tibial tray 314 between the medial and lateral portions 320 and 322. The slot 374 can be configured to accommodate and provide clearance for a host ACL and/or PCL or a reconstructed ACL and/or PCL. A retaining rail 375 can be formed around a posterior edge of the medial portion 320. The retaining rail 375 can include a lip 376 and a groove 378. A retaining rail 380 can be formed around a posterior edge of the lateral portion 322 of the tibial tray 314. The retaining rail 380 can generally include a lip 382 and a groove 384. An inferior surface 386 of the tibial tray 314 can be generally smooth, but may also incorporate a series of round grooved pegs. The inferior surface 386 can be configured to be cemented or press-fit onto the proximal tibia. The tibial tray 314 can be generally manufactured of cobalt-chromium-molybdenum alloy or other suitable biocompatible materials.
Attaching the mobile bearing component 316 to the medial portion 320 of the tibial tray 314 will now be described according to one example. At the outset, the surgeon can select a given mobile bearing component 316 from a plurality of medial bearing components (see also kit 600,
Connection of the fixed bearing component 318 to the lateral portion 322 of the tibial tray 314 is similarly carried out. Initially, the inferior surface 364 of the fixed bearing component 318 is located onto the lateral portion 322 of the tibial tray 314. Next, the fixed bearing component 318 is slidably advanced posteriorly, such that the channel 362 slidably accommodates the locating tab 372 while the groove 368 locates under the lip 382. The fixed bearing component 318 is adapted to be statically secured relative to the lateral portion 322 of the tibial tray when assembled.
With reference now to
The tibial tray 414 can include a medial portion 436, a lateral portion 438, posterior engagement tabs 440, an anterior engagement bridge 442 and anterior engagement tabs 443. The anterior engagement bridge 442 can include a track 444 formed thereon. The anterior engagement bridge 442 can provide an increased thickness to the tibial tray 414 at the connection between the medial and lateral portion 436 and 438, respectively to increase durability. A wall 446 can be formed on the anterior engagement bridge 442 adjacent to the track 444. The tibial tray 414 can have inferiorly extending posts 450.
The locking bar 420 can generally include a body 454 having a finger 456 extending therefrom. A catch 458 can be formed on a terminal end of the finger 456. The locking bar 420 can be formed of biocompatible metallic material, such as titanium for example. The body 454 can further include a leading end 460 and a trailing end 462.
Attaching the respective first and second bearing components 416 and 418 to the tibial tray 414 according to one example of the present teachings will now be described. Once a surgeon has selected a first and second bearing component 416 and 418 that satisfies the given needs of a particular patient (see also kit 600,
With reference now to
Turning now to
As used herein, the terms superior, superiorly, superior direction are used to generally refer to the anatomical meaning, such as higher in place or position or generally situated above. Similarly, the terms inferior, inferiorly, inferior direction are used to generally refer to the anatomical meaning, such as lower in place or position or generally situated below.
Turning now to
The respective components of the knee prosthesis assembly 610 can be patient specific, such that each component can be constructed for optimal features for a given patient. For example, the bone interface margins of the femoral component 612 and tibial tray 614 can be patient specific for optimized bone coverage. In addition, the overall size, such as anterior-posterior dimensions and bone cut geometry can be determined and used for manufacturing the components of the knee prosthesis assembly 610. Moreover, some articulation features can be determined and used as criteria for forming the components of the knee prosthesis assembly 610. In sum, each of the components of the knee prosthesis assembly 610 can be a patient-specific implant, a semi-custom implant or an off-the-shelf or standard production implant. A custom-made implant is a patient-specific, one-of-a-kind implant specifically made for a particular patient, and consequently there is no excess inventory associated with multiple sizes of implants. Other configurations are contemplated.
The femoral component 612 will now be described in greater detail. The femoral component 612 can generally comprise a cruciate retaining prosthesis and includes various portions to replace or mimic the distal femur. The femoral component 612 can include a medial condyle portion 619a and a lateral condyle portion 619b. The condyle portions 619a and 619b can replace the medial and lateral condyles of a distal femur. The medial and lateral condyle portions 619a and 619b can interconnect and be formed as a single piece with a patellar track portion 621. The patellar track portion 621 can allow for articulation of a patella, either natural or prosthetic patella, once the femoral component 612 is implanted into the distal femur. The medial and lateral condyle portions 619a and 619b and the patellar track portion 621 can generally define an exterior portion of the femoral component 612. The femoral component 612 can define an opening or passage 623 between the medial and lateral condyle portions 619a and 619b. As can be appreciated, the passage 623 can accommodate, and provide clearance for a host ACL and/or PCL or a reconstructed ACL and/or PCL.
The femoral component 612 can include a bone contacting or inferior surface 625 (
With reference now to
The tibial tray 614 can include a medial portion 637a, a lateral portion 637b, posterior engagement lips 640, an anterior engagement bridge 642, and outer securing lips 643. The anterior engagement bridge 642 can include a track 644 formed thereon. The anterior engagement bridge 642 can provide an increased thickness to the tibial tray 614 at the connection between the medial and lateral portions 637a and 637b, respectively to increase durability. The tibial tray 614 can have inferiorly extending keels 648 and inferiorly extending posts 650.
The locking bar 620 can generally include a body 654 having a finger 656 extending therefrom. A catch 658 can be formed on a terminal end of the finger 656. The locking bar 620 can be formed of biocompatible metallic material, such as titanium for example. The body 654 can further include a leading end 660 and a trailing end 662.
Attaching the respective first and second bearing components 616 and 618 to the tibial tray 614 according to one example of the present teachings will be described. Once a surgeon has selected a first and second bearing components 616 and 618 (such as from a kit 700,
With reference now to
The tibial tray 714 can include a medial portion 736, a lateral portion 738, posterior engagement lips 740, an anterior engagement bridge 742, and outer securing lips 743. The anterior engagement bridge 742 can include a track 744 formed thereon. The anterior engagement bridge 742 can provide an increased thickness to the tibial tray 714 at the connection between the medial and lateral portions 736 and 738, respectively to increase durability.
Attaching the respective first and second bearing components 716 and 718 to the tibial tray 714 according to one example of the present teachings will be described. Once a surgeon has selected a first and second bearing components 716 and 718 (such as from the kit 700,
Turning now to
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Claims
1. A knee joint prosthesis assembly comprising:
- a femoral component including a first condyle and a second condyle; and
- a unitary tibial component including: an engaging structure configured to rigidly secure a stationary bearing thereto, the stationary bearing configured to articulate with the first condyle; and a planar tibial bearing surface configured to slidably support a mobile bearing thereon, the mobile bearing including an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle.
2. The knee joint prosthesis assembly of claim 1, wherein the mobile bearing is configured to slide only in an anterior-posterior direction.
3. The knee joint prosthesis assembly of claim 1, wherein the mobile bearing is a floating bearing.
4. The knee joint prosthesis assembly of claim 1, wherein the unitary tibial component includes a rail extending anterior-posterior, the mobile bearing is configured to slide along the rail.
5. The knee joint prosthesis assembly of claim 1, wherein the engaging structure of the unitary tibial component includes a plurality of coupling members extending superiorly and configured to couple directly with the stationary bearing.
6. The knee joint prosthesis assembly of claim 1, wherein the stationary bearing is a lateral bearing and the mobile bearing is a medial bearing.
7. The knee joint prosthesis assembly of claim 1, wherein the stationary bearing is a medial bearing and the mobile bearing is a lateral bearing.
8. The knee joint prosthesis assembly of claim 1, wherein a rail restricts rotation of the mobile bearing.
9. A knee joint prosthesis assembly comprising:
- a femoral component including a first condyle and a second condyle connected by a patellar track portion, the femoral component defining an opening between the first condyle and the second condyle; and
- a unitary tibial component including: an engaging structure configured to rigidly secure a stationary bearing thereto, the stationary bearing configured to articulate with the first condyle; a planar tibial bearing surface configured to slidably support a mobile bearing thereon, the mobile bearing including an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle; and a rail extending in an anterior-posterior direction and configured to restrict the mobile bearing to anterior-posterior movement.
10. The knee joint prosthesis of claim 9, wherein the rail abuts a side surface of the mobile bearing.
11. The knee joint prosthesis of claim 9, wherein the rail protrudes superiorly.
12. The knee joint prosthesis of claim 9, wherein the rail is between the mobile bearing and the stationary bearing.
13. The knee joint prosthesis of claim 9, wherein the mobile bearing is a medial bearing and the stationary bearing is a lateral bearing.
14. The knee joint prosthesis of claim 9, wherein the unitary tibial component defines a slot between the rail and the engaging structure.
15. A knee joint prosthesis assembly comprising:
- a femoral component including a first condyle and a second condyle connected by a patellar track portion, the femoral component defining an opening between the first condyle and the second condyle; and
- a unitary tibial component including: a medial portion, a lateral portion, and a slot defined between the medial portion and the lateral portion; an engaging structure extending superiorly from one of the medial portion or the lateral portion, the engaging structure configured to rigidly secure a stationary bearing thereto, the stationary bearing configured to articulate with the first condyle; a planar tibial bearing surface at the other of the medial portion or the lateral portion, the planar tibial bearing surface configured to slidably support a mobile bearing thereon, the mobile bearing including an inferior planar surface configured to slide along the planar tibial bearing surface and a superior surface configured to articulate with the second condyle; and a rail between the planar tibial bearing surface and the engaging structure, the rail extending in an anterior-posterior direction and configured to restrict the mobile bearing to anterior-posterior movement.
16. The knee joint prosthesis assembly of claim 15, wherein the engaging structure extends from the lateral portion and the planar tibial bearing surface is at the medial portion.
17. The knee joint prosthesis assembly of claim 15, wherein the rail abuts an inner surface of the mobile bearing.
18. The knee joint prosthesis assembly of claim 15, wherein the mobile bearing is a floating bearing.
19. The knee joint prosthesis assembly of claim 15, wherein the rail protrudes superiorly away from the planar tibial bearing surface.
20. The knee joint prosthesis assembly of claim 15, wherein the engaging structure includes tabs at an anterior portion and a posterior portion of the unitary tibial component.
Type: Application
Filed: Oct 15, 2014
Publication Date: Jan 29, 2015
Inventors: Robert Metzger (Wakarusa, IN), James G. Lancaster (Winona Lake, IN)
Application Number: 14/514,453