Femoral component for a knee prosthesis with improved articular characteristics

Patent metadata

Field	Value
Publication number	US-10045850-B2
Application number	US-201615092107-A
Country	US
Kind code	B2
Filing date	Apr 6, 2016
Priority date	Jun 16, 2011
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

An orthopaedic knee prosthesis includes a femoral component which exhibits enhanced articular features, minimizes removal of healthy bone stock from the distal femur, and minimizes the impact of the prosthesis on adjacent soft tissues of the knee.

First claim

What is claimed is:

1. A family of femoral components for a knee prosthesis, each of said family of femoral components adapted to articulate with a tibial articular surface and a patellar articular surface, each of said family of femoral components comprising:
a medial condyle comprising:
a medial condylar surface shaped to articulate with a medial compartment of the tibial articular surface through a range of motion in which full extension corresponds to zero degrees flexion of the knee prosthesis and positive flexion corresponds to greater than zero degrees flexion of the knee prosthesis, said medial condylar surface comprising a medial distal-most point positioned to contact the tibial articular surface at the full extension, a medial posterior-most point positioned to contact the tibial articular surface at 90-degrees flexion, and a medial proximal-most point; and
a medial bone-contacting surface disposed opposite said medial condylar surface and positioned to abut a resected femur upon implantation of a respective one of the family of femoral components;
a lateral condyle separated from said medial condyle by a component sagittal plane extending along an anterior/posterior direction and a proximal/distal direction, said lateral condyle comprising:
a lateral condylar surface shaped to articulate with a lateral compartment of the tibial articular surface through the range of motion, said lateral condylar surface comprising a lateral distal-most point positioned to contact the tibial articular surface at the full extension, a lateral posterior-most point positioned to contact the tibial articular surface at 90-degrees flexion and a lateral proximal-most point; and
a lateral bone-contacting surface disposed opposite said lateral condylar surface and positioned to abut the resected femur upon implantation of a respective one of the family of femoral components; and
a patellar flange extending anteriorly from said medial and lateral condyles, said patellar flange comprising:
a flange articular surface shaped to articulate with the patellar articular surface;
an anterior bone-contacting surface disposed opposite said flange articular surface and positioned to abut an anterior facet of the resected femur upon implantation of a respective one of the family of femoral components; and
medial and lateral flange walls extending between said flange articular surface to said anterior bone-contacting surface;
each said family of femoral components comprising an outer periphery defining a plurality of peripheral characteristics, said peripheral characteristics comprising:
a medial/lateral component width defined as the overall distance between said medial and lateral condyles along a medial/lateral direction normal to the component sagittal plane,
a condylar height defined as the larger of a medial condyle height and a lateral condyle height, in which said medial condyle height is the distance from said medial distal-most point to said medial proximal-most point along the proximal/distal direction said lateral condyle height is the distance from said lateral distal-most point to said lateral proximal-most point along the proximal/distal direction; and
a patellar flange height defined as the distance between i) an imaginary line connecting said medial and lateral distal-most points and ii) a proximal peak of said patellar flange, said patellar flange height measured along the proximal/distal direction;
said family of femoral components comprising a regular femoral component and a narrow femoral component sharing a common anterior/posterior space between said anterior bone-contacting surface of said patellar flange and said medial and lateral bone-contacting surfaces of said medial and lateral condyles, respectively, whereby said family of femoral components are compatible with a common sagittal femoral resection geometry,
at least one of said plurality of peripheral characteristics of said regular femoral component larger than the corresponding one of said plurality of peripheral characteristics of said narrow femoral component.

2. The family of femoral components of claim 1 , wherein a sagittal profile of said narrow femoral component is nominally subsumed by a sagittal profile of said regular femoral component, whereby said regular and narrow femoral components are compatible with a common femoral resection profile.

3. The family of femoral components of claim 1 , wherein at least two of said plurality of peripheral characteristics of said regular femoral component are larger than a corresponding at least two of said plurality of peripheral characteristics of said narrow femoral component.

4. The family of femoral components of claim 1 , wherein each of said plurality of peripheral characteristics of said regular femoral component is larger than the corresponding one of said plurality of peripheral characteristics of said narrow femoral component.

5. The family of femoral components of claim 1 , wherein said medial/lateral component width of said regular femoral component is larger than said medial/lateral component width of said narrow femoral component by between 4 mm and 6 mm.

6. The family of femoral components of claim 1 , wherein said medial condyle height of said regular femoral component is larger than said medial condyle height of said narrow femoral component by 1 mm.

7. The family of femoral components of claim 1 , wherein said lateral condyle height of said regular femoral component is larger than said lateral condyle height of said narrow femoral component by 1 mm.

8. The family of femoral components of claim 1 , wherein said patellar flange height of said regular femoral component is larger than said patellar flange height of said narrow femoral component by 1 mm.

9. The family of femoral components of claim 1 , wherein:
each said family of femoral components defines a femoral component coordinate system comprising the component sagittal plane extending along the proximal/distal direction and the anterior/posterior direction, the component sagittal plane equidistant from said medial and lateral condylar walls;
said flange articular surface of said patellar flange comprising a sulcus groove defining a longitudinal groove axis, said groove axis defining an angle with said imaginary line connecting said medial and lateral distal-most points; and
said angle defined by said regular femoral component larger than said angle defined by said narrow femoral component.

10. The family of femoral components of claim 9 , wherein said angle between said groove axis and said imaginary line is 83 degrees for said regular femoral component and 80 degrees for said narrow femoral component.

11. The family of femoral components of claim 1 , wherein said medial and lateral flange walls of said patellar flange converge toward said proximal peak of said patellar flange to define a flange wall angle,
said flange wall angle of said narrow femoral component different from said flange wall angle of said regular femoral component.

12. The family of femoral components of claim 1 , wherein each of said family of femoral components comprises an anterior/posterior space formed between said anterior bone-contacting surface and said medial and lateral bone-contacting surfaces, and wherein:
a plurality of said regular femoral components each comprise a unique nominal value for said anterior/posterior space; and
a plurality of said narrow femoral components, said anterior/posterior space of each of said plurality of said narrow femoral components equal to one of the unique nominal values defined by said plurality of said regular femoral components.

13. The family of femoral

Assignees

• Zimmer Inc

Inventors

• Parisi Raymond C
• Drury Nick
• Baldridge Charles A
• Harris James C

Classifications

• A61F2/3886

  for stabilising knees against anterior or lateral dislocations · CPC title

• A61F2/3859 Primary

  Femoral components · CPC title

• A61F2002/3863

  Condyles fitted on an anchored base · CPC title

• A61F2002/30616

  Sets comprising a plurality of prosthetic parts of different sizes or orientations · CPC title