CRUCIATE-RETAINING KNEE PROSTHESIS

• US 20110190898A1
• Filed: 01/28/2011
• Published: 08/04/2011
• Est. Priority Date: 01/29/2010
• Status: Active Grant

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Inventors: MCKINNON, BRIAN W., SMITH, RICHARD MICHAEL, JERRY, GERALD J., NIELSEN, JONATHAN KIRK, WILKINSON, ZACHARY CHRISTOPHER, SALEHI, ABRAHAM B., LENZ, NATHANIEL M., RIES, MICHAEL D.
• Granted Patent: US 8,900,316 B2
• Time in Patent Office: Days
• US Class Current: 623/20.32
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30326 differing in height or in length
• CPC Class Codes: A61F 2002/30535 Special structural features of bone or joint prostheses not otherwise provided for
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30688 Means for allowing passage or sliding of tendons or ligaments
• CPC Class Codes: A61F 2002/30884 Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/3895 unicompartimental

Abstract

Certain embodiments generally provide an improved tibial base member comprising keel portions that allow one or both cruciate ligaments to be preserved. Other embodiments provide improved lateral and/or medial inserts having a mesial lip that helps relieve and/or prevent impingement between the femoral component and the tibial eminence. Other embodiments provide improved femoral components having various chamfers to provide additional clearance with respect to the tibial eminence and posterior cruciate ligament without decreasing bone coverage.

Claims

1. A tibial prosthesis for at least partially replacing a proximal portion of a tibia, the tibial prosthesis comprising:

(a) an inferior surface for contact with a resected surface on the proximal portion of the tibia; and

(b) a keel for penetration into a cavity formed in the proximal tibia, wherein the keel extends at an inferior-posterior angle away from the inferior surface.

2. The tibial prosthesis of claim 1, wherein the keel includes an anterior keel portion, a medial keel portion, and a lateral keel portion, and wherein the anterior keel portion extends at the inferior-posterior angle away from the inferior surface.

3. The tibial prosthesis of claim 2, wherein the tibial prosthesis further comprises a medial baseplate portion, a lateral baseplate portion, and a connecting baseplate portion extending between and connecting the medial baseplate portion and lateral baseplate portion;

wherein at least a part of the anterior keel portion extends in a generally medial-lateral direction on the connecting baseplate portion;

wherein at least a part of the medial keel portion extends in a generally anterior-posterior direction on the medial baseplate portion; and

wherein at least a part of the lateral keel portion extends in a generally anterior-posterior direction on the lateral baseplate portion.

4. The tibial prosthesis of claim 3, wherein the anterior keel portion joins the medial and lateral keel portions at areas of increased thickness.

5. The tibial prosthesis of claim 3, wherein the anterior keel portion joins the medial and lateral keel portions at areas of increased width.

6. The tibial prosthesis of claim 3, wherein the connecting baseplate portion increases in thickness in an anterior to posterior direction.

7. The tibial prosthesis of claim 3, wherein the medial and lateral keel portions decrease in height as the medial and lateral keel portions extend in an anterior to posterior direction.

8. The tibial prosthesis of claim 2, wherein the anterior keel portion includes an anterior face and a posterior face, wherein the anterior face extends at an inferior-posterior anterior face angle away from the inferior surface;

and wherein the posterior face extends at an inferior-posterior posterior face angle away from the inferior surface.

9. The tibial prosthesis of claim 2, wherein the anterior keel portion extends across the connecting baseplate portion in an anterior-medial to a posterior-lateral direction.

10. The tibial prosthesis of claim 9, wherein the tibial prosthesis defines a central notch extending between the medial and lateral baseplate portions posterior to the connecting baseplate portion, wherein the central notch has a sufficient width and length to receive a portion of a tibial eminence including an anterior cruciate ligament attachment site and a posterior cruciate ligament attachment site.

11. The tibial prosthesis of claim 10, wherein the central notch comprises a medial edge and a lateral edge;

wherein an angle defined by the medial edge and a base of the anterior keel portion is acute; and

wherein an angle defined by the lateral edge and the base of the anterior keel portion is obtuse.

12. The tibial prosthesis of claim 3, wherein a posterior face of the anterior keel portion is offset from a posterior face of the connecting baseplate portion.

13. The tibial prosthesis of claim 2, wherein a superior surface of the tibial prosthesis includes at least one lock member for securing a tibial insert.

14. The tibial prosthesis of claim 2, wherein a superior surface of the tibial prosthesis includes at least two lock members for securing a medial tibial insert and a lateral tibial insert.

15. A tibial prosthesis for at least partially replacing a proximal portion of a tibia, the tibial prosthesis comprising:

(a) a medial baseplate portion, the medial baseplate portion having a medial inferior surface for contact with a medial resected surface on the proximal portion of the tibia;

(b) a lateral baseplate portion, the lateral baseplate portion having an lateral inferior surface for contact with a lateral resected surface on the proximal portion of the tibia; and

(c) a connecting baseplate portion extending between the medial and lateral baseplate portions;

wherein the tibial prosthesis is asymmetric about a midline extending in an anterior-posterior direction between the medial and lateral baseplate portions and the medial baseplate portion extends further anteriorly than the lateral baseplate portion.

16. The tibial prosthesis of claim 15, wherein an area defined by the medial baseplate portion in a transverse plane is greater than an area defined by the lateral baseplate portion in the transverse plane.

17. The tibial prosthesis of claim 15, wherein the tibial prosthesis is a bicruciate-retaining tibial prosthesis.

18. The tibial prosthesis of claim 15, wherein the tibial prosthesis defines a notch extending in a generally anterior-posterior direction between the medial and lateral baseplate portions and is positioned posterior to the connecting baseplate portion;

and wherein the notch is of sufficient length to receive at least a portion of an eminence of the tibia including an anterior cruciate ligament attachment site and a posterior cruciate ligament attachment site.

19. The tibial prosthesis of claim 18, wherein the notch comprises a medial edge, a lateral edge, and an anterior edge;

wherein an angle defined by the medial and anterior edges is acute; and

wherein an angle defined by the lateral and anterior edges is obtuse.

20. A tibial prosthesis for at least partially replacing a proximal portion of a tibia, the tibial prosthesis comprising:

(a) a medial baseplate portion comprising a medial inferior surface for contact with a medial resected surface on the proximal portion of the tibia;

(b) a lateral baseplate portion comprising a lateral inferior surface for contact with a lateral resected surface on the proximal portion of the tibia;

(c) a connection baseplate portion extending between the medial and lateral baseplate portions, the connection baseplate portion comprising a connection inferior surface;

(d) a keel for penetration into a cavity formed in the proximal tibia, wherein the keel extends at an inferior-posterior angle away from at least one of the medial inferior surface, the lateral inferior surface, and the connection inferior surface.

21. The tibial prosthesis of claim 20, wherein the keel includes an anterior keel portion, a medial keel portion extending from the medial inferior surface, and a lateral keel portion extending from the lateral inferior surface,

wherein the anterior keel portion extends at the inferior-posterior angle away from the connection inferior surface.

22. The tibial prosthesis of claim 21, wherein at least a part of the anterior keel portion extends in a generally medial-lateral direction on the connection baseplate portion, wherein at least a part of the medial keel portion extends in a generally anterior-posterior direction on the medial baseplate portion, and wherein at least a part of the lateral keel portion extends in a generally anterior-posterior direction on the lateral baseplate portion.

23. The tibial prosthesis of claim 21, wherein the anterior keel portion joins the medial and lateral keel portions at areas of increased thickness.

24. The tibial prosthesis of claim 21, wherein the anterior keel portion joins the medial and lateral keel portions at areas of increased width.

25. The tibial prosthesis of claim 21, wherein the connection baseplate portion increases in thickness in an anterior posterior direction.

26. The tibial prosthesis of claim 21, wherein the medial and lateral keel portions decrease in height as the medial and lateral keel portions extend in an anterior to posterior direction.

27. The tibial prosthesis of claim 21, wherein the anterior keel portion extends across the connection baseplate portion in an anterior-medial to a posterior-lateral direction.

28. The tibial prosthesis of claim 21, wherein a posterior face of the anterior keel portion is offset from a posterior face of the connection baseplate portion.

29. The tibial prosthesis of claim 21, wherein the tibial prosthesis defines a central notch extending between the medial and lateral baseplate portions posterior to the connection baseplate portion, wherein the central notch has a sufficient width and length to receive a portion of a tibial eminence including an anterior cruciate ligament attachment site and a posterior cruciate ligament attachment site.

30. The tibial prosthesis of claim 29, wherein the central notch comprises a medial edge and a lateral edge, wherein an angle defined by the medial edge and a base of the anterior keel portion is acute;

and wherein an angle defined by the lateral edge and the base of the anterior keel portion is obtuse.

31. The tibial prosthesis of claim 20, wherein the tibial prosthesis is asymmetric about a midline extending in an anterior-posterior direction between the medial and lateral baseplate portions and the medial baseplate portion extends further anteriorly than the lateral baseplate portion.

32. The tibial prosthesis of claim 20, further comprising at least one tibial articulation surface for articulation with a femoral condylar articulation surface of a femoral component,

wherein the tibial articulation surface defines a mesial lip extending in an anterior to posterior direction along a mesial edge of the articulation surface;

wherein the mesial lip is raised by a height relative to a corresponding central portion of the articulation surface.

33. The tibial prosthesis of claim 32, wherein the femoral component comprises a medial condyle and a lateral condyle and wherein at least one of the medial condyle and the lateral condyle comprises a posterolateral chamfer.

34. The tibial prosthesis of claim 32, wherein the at least one tibial articulation surface generally slopes in an anterior-posterior direction.

35. The tibial prosthesis of claim 34, wherein the at least one tibial articulation surface comprises a medial articulation surface and a lateral articulation surface, and wherein a slope of the medial articulation surface in the anterior-posterior direction is different from a slope of the lateral articulation surface in the anterior-posterior direction.

36. The tibial prosthesis of claim 35, wherein the medial articulation surface is associated with a medial insert and the lateral articulation surface is associated with a lateral insert, wherein a thickness of the medial insert at an anterior portion of the medial insert is different than a thickness of the lateral insert at a posterior portion of the lateral insert.

37. The tibial prosthesis of claim 36, wherein the thickness of the medial insert at the anterior portion of the medial insert is greater than the thickness of the medial insert at a posterior portion of the medial insert.

38. The tibial prosthesis of claim 36, wherein a thickness of the medial insert at a posterior portion of the medial insert is different than a thickness of the lateral insert at a posterior portion of the lateral insert.

39. The tibial prosthesis of claim 36, wherein the thickness of the lateral insert at the anterior portion of the lateral insert is greater than the thickness of the lateral insert at a posterior portion of the lateral insert.

40. The tibial prosthesis of claim 34, wherein the at least one tibial articulation surface generally slopes in a medial-lateral direction.

41. The tibial prosthesis of claim 40, wherein the at least one tibial articulation surface comprises a medial articulation surface and a lateral articulation surface, and wherein a slope of the medial articulation surface in the medial-lateral direction is different from a slope of the lateral articulation surface in the medial-lateral direction.

42. The tibial prosthesis of claim 41, wherein the medial articulation surface is associated with a medial insert and the lateral articulation surface is associated with a lateral insert, wherein a thickness of the medial insert at an anterior portion of the medial insert is greater than a thickness of the lateral insert at an anterior portion of the lateral insert, and wherein the thickness of the medial insert at a posterior portion of the medial insert is different than the thickness of the lateral insert at a posterior portion of the lateral insert.

43. The tibial prosthesis of claim 36, wherein the medial insert and the lateral insert are part of a kit of inserts having varying slopes in the anterior-posterior direction.

44. The tibial prosthesis of claim 21, wherein the anterior keel portion is positioned anteriorly on the connection inferior surface to engage anterior cortical bone when implanted in a patient.

45. The tibial prosthesis of claim 34, wherein the at least one tibial articulation surface is associated with a tibial base plate.