Femoral augments for use with knee joint prosthesis

Patent metadata

Field	Value
Publication number	US-10893947-B2
Application number	US-201816122540-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Aug 27, 2001
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A femoral augment, or set of augments, for use with a knee joint prosthesis, where the femoral augment includes a main body portion, an aperture formed within the main body portion and extending in a generally distal/proximal direction, and a pair of legs extending outwardly from said main body portion in a generally posterior direction. In the preferred embodiment, the aperture is configured to receive a stem extension implant, and to allow it to pass through. Additionally, the legs of the femoral augment are preferably configured to be seated proximal of a proximal side of a pair of condylar portions of a femoral component of a knee joint prosthesis. The present invention is intended for situations in which the distal portion of the femur is defective, and it provides a method and devices that allow for preservation of healthy peripheral bone, while still providing the necessary augmentation to the distal portion of the femur.

First claim

What is claimed is:

1. A femoral implant system implantable in a distal femur of a patient, the femoral implant system comprising:
a femoral component that is implantable in the distal femur of the patient as part of a knee joint prosthesis, the femoral component comprising a stem component to facilitate securing the femoral component to the distal femur, a medial condyle, and a lateral condyle, the medial condyle and the lateral condyle each including a proximal side; and
a femoral augment for augmenting the femoral component in the distal femur, the femoral augment comprising:
a proximal body portion through which the stem component can be received;
a lateral leg that extends distally from the proximal body portion to be seated proximally of the proximal side of the lateral condyle when the femoral component and the femoral augment are implanted in the distal femur;
a medial leg that extends distally from the proximal body portion to be seated proximally of the proximal side of the medial condyle when the femoral component and the femoral augment are implanted in the distal femur; and
a web portion,
wherein the lateral leg, the medial leg, and the web portion define a recessed portion for accommodating receipt of the femoral component when the femoral component and the femoral augment are implanted in the distal femur, the recessed portion extending across a proximal-distal extent, the recessed portion defining a medial-lateral width at a distal end of the proximal-distal extent that is wider than a medial-lateral width at a proximal end of the proximal-distal extent, wherein the proximal body portion, the web portion, the lateral leg, and the medial leg are formed together as a single unit,
wherein the femoral augment is formed separately from the femoral component and has an overall height in the range of 30 mm to 50 mm,
wherein an outer surface of the femoral augment is porous for facilitating bony ingrowth into the femoral augment when the femoral augment is implanted in the distal femur.

2. The femoral implant system of claim 1 , wherein the femoral augment includes a proximal surface from which the proximal body portion extends in a distal direction, the proximal surface defining a first medial-lateral extent, the proximal body portion defining a second medial-lateral extent that is larger than the first medial-lateral extent, the medial leg and the lateral leg cooperating to define a third medial-lateral extent that is larger than the first medial-lateral extent and the second medial-lateral extent.

3. The femoral implant system of claim 1 , wherein the femoral component includes a medial inner rail that includes a proximal surface situated proximally of the proximal side of the medial condyle and a lateral inner rail that includes a proximal surface situated proximally of the proximal side of the lateral condyle.

4. The femoral implant system of claim 1 , wherein the stem component is an elongate stem extension implant for insertion into and securement to the distal femur.

5. The femoral implant system of claim 1 , wherein the proximal body portion includes a tapered outer lateral surface and a tapered outer medial surface that each are tapered inwardly in a distal-to-proximal direction.

6. The femoral implant system of claim 5 , wherein the tapered outer lateral surface and the tapered outer medial surface are differently tapered such that the proximal body portion is asymmetric with respect to a lateral side and a medial side of the proximal body portion.

7. The femoral implant system of claim 1 , wherein the medial-lateral width at the distal end of the proximal-distal extent defines a widest medial-lateral width of the recessed portion and the medial-lateral width at the proximal end of the proximal-distal extent defines a narrowest medial-lateral width of the recessed portion.

8. The femoral implant system of claim 1 , wherein the medial leg and the lateral leg each extend outwardly from the proximal body portion in a posterior direction.

9. The femoral implant system of claim 1 , wherein the overall height of the femoral augment is in the range of 40 mm to 50 mm.

10. The femoral implant system of claim 1 , wherein the lateral leg and the medial leg each include an inner leg area, and wherein the inner leg areas are sloped toward each other in a distal to proximal direction.

11. The femoral implant system of claim 1 , wherein the lateral leg and the medial leg each include an outer leg surface, and wherein the outer leg surfaces are sloped toward each other in a distal to proximal direction.

12. A femoral implant system implantable in a distal femur of a patient, the femoral implant system comprising:
a femoral component that is implantable in the distal femur of the patient as part of a knee joint prosthesis, the femoral component comprising a stem component to facilitate securing the femoral component to the distal femur, a medial condyle, and a lateral condyle, the medial condyle and the lateral condyle each including a proximal side; and
a femoral augment for augmenting the femoral component in the distal, the femoral augment comprising:
a proximal surface that defines a first medial-lateral extent of the femoral augment;
a proximal body portion through which the stem component can be received, the proximal body portion extending distally from the proximal surface of the femoral augment and defining a second medial-lateral extent of the femoral augment that is larger than the first medial-lateral extent;
a lateral leg that extends distally from the proximal body portion to be seated proximally of the proximal side of the lateral condyle when the femoral component and the femoral augment are implanted in the distal femur;
a medial leg that extends distally from the proximal body portion to be seated proximally of the proximal side of the medial condyle when the femoral component and the femoral augment are implanted in the distal femur; and
a web portion,
wherein the lateral leg, the medial leg, and the web portion define a recessed portion for accommodating receipt of the femoral component when the femoral component and the femoral augment are implanted in the distal femur,
wherein the lateral leg and the medial leg each include an outer leg surface, and wherein the outer leg surfaces are sloped toward each other in a distal to proximal direction,
wherein the femoral augment is formed separately from the femoral component and has an overall height in the range of 30 mm to 50 mm,
wherein an outer surface of the femoral augment is porous for facilitating bony ingrowth into the femoral augment when the femoral augment is implanted in the distal femur.

13. The femoral implant system of claim 12 , wherein the proximal body portion, the web portion, the lateral leg, and the medial leg are formed together as a single unit.

14. The femoral implant system of claim 12 , wherein the medial leg and the lateral leg cooperate to define a third medial-lateral extent that is larger than the first medial-lateral extent and the second medial-lateral extent.

15. The femoral implant system 25 , wherein the stem component is a stem base.

16. The femoral implant system of claim 12 , wherein the proximal body portion includes a tapered outer lateral surface and a tapered outer medial surface that each are tapered inwardly in a distal-to-proximal direction.

17. The femoral implant system of claim 12 , wherein the medial leg and the lateral leg each extend outwardly from the proximal body portion in a posterior direction.

18. The femoral implant syste

Assignees

• Zimmer Inc

Inventors

• Blaylock Jeff
• Cook Michael
• Donkers Ron
• Dykema Scott
• Hall Maleata
• Meyers John E
• Hanssen Arlen D
• Lewallen David

Classifications

• A61F2002/4631

  the prosthesis being specially adapted for being cemented · CPC title

• A61F2/30734

  Modular inserts, sleeves or augments, e.g. placed on proximal part of stem for fixation purposes or wedges for bridging a bone defect · CPC title

• A61F2002/30827

  Plurality of grooves · CPC title

• A61F2002/30736

  Augments or augmentation pieces, e.g. wedges or blocks for bridging a bone defect · CPC title

• A61F2310/00544

  Coating made of tantalum or Ta-based alloys · CPC title