Apparatus for sizing a femoral component

• US 5,562,675 A
• Filed: 05/09/1995
• Issued: 10/08/1996
• Est. Priority Date: 09/01/1992
• Status: Expired due to Term

• Current Assignee: DePuy Orthopaedics Incorporated (Johnson & Johnson)
• Original Assignee: DePuy Incorporated (Johnson & Johnson)
• Inventors: Kelman, David C., McNulty, Donald E., Hamm, John E., Moreland, John R.
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): Tucker, Guy V.
• Application Number:
  US08/437,848
• Time in Patent Office: 518 Days
• Field of Search: 606/87, 606/88, 606/102, 606/86, 606/82, 606/80, 606/96, 606/79, 623/18, 623/20
• US Class Current: 606/96
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations

Abstract

A sizing assembly for determining the optimum size of a femoral component of a knee prosthesis is placed against the resected distal end of a femur. The assembly includes a body with a flat surface for contacting the resected surface of the femur and feet for engaging the femoral condyles. The assembly further includes a pivoted stylus that slides in the body and engages the anterior femoral cortex. Once the size of the femoral component is determined, a drill bushing corresponding to the femoral component is supported on the body. The drill bushing includes two apertures for guiding a drill to bore pilot holes in the resected femur.

Claims

1. A sizing and drilling assembly for determining the optimum size femoral component to couple to a resected distal end of a femur from a group of femoral components having various sizes and condyle thicknesses, the assembly comprising:

a body portion including a flat contact surface for engaging the resected end of the femur;

a plurality of feet coupled to a bottom surface of the body for engaging posterior femoral condyles to align the body portion with the resected distal end of the femur;

a stylus assembly slidably coupled to the body portion, the stylus assembly including an arm extending away from the body portion and a stylus coupled to the arm, the stylus assembly being movable relative to said body portion until the stylus engages the anterior femoral cortex;

means on the stylus assembly and body portion for indicating the size of femoral component corresponding to the resected femur based on the position of the stylus assembly relative to the body portion a plurality of drill bushings of various sizes; and

means coupled to the stylus assembly for supporting a drill bushing selected from the plurality of drill bushings, said selected bushing corresponding to the size of the femoral component indicated by the indicating means.

2. The assembly of claim 1, wherein the supporting means aligns the drill bushing relative to the anterior femoral cortex.

3. The assembly of claim 1, wherein each drill bushing includes first and second apertures for guiding a drill to bore pilot holes in the resected femur for securing the femoral component to the resected femur.

4. The assembly of claim 1, wherein the arm of the stylus assembly is pivotable so that the stylus is parallel to the anatomical axis of the femur.

5. The assembly of claim 1, further comprising first and second captured fixation pins coupled to the body portion for securing the body portion to the resected distal end of the femur.