Custom replacement device for resurfacing a femur and method of making the same

• US 6,712,856 B1
• Filed: 03/17/2000
• Issued: 03/30/2004
• Est. Priority Date: 03/17/2000
• Status: Expired due to Term

• Current Assignee: Kinamed Inc (VME Acquisition Corp)
• Original Assignee: Kinamed Inc (VME Acquisition Corp)
• Inventors: Carignan, Roger, Pratt, Clyde R.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/528,128
• Time in Patent Office: 1,474 Days
• Field of Search: 623/20.35, 623/20.31, 623/20.3, 623/20.32, 623/21.11, 623/21.12, 623/21.14, 623/20.18, 623/20.19, 623/20.2, 623/20.21, 623/20.14, 623/11.11
• US Class Current: 623/20.35
• CPC Class Codes: A61B 17/00491 Surgical glue applicators surgical adhesives A61L24/00; two-component delivery syringes A61M5/19
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2034/108 Computer aided selection or customisation of medical implants or cutting guides
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30942 for designing or making customized prostheses, e.g. using templates, CT or NMR scans, finite-element analysis or CAD-CAM techniques
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/3877 Patellae or trochleae
• CPC Class Codes: A61F 2/461 of knees
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30594 slotted, e.g. radial or meridian slot ending in a polar aperture, non-polar slots, horizontal or arcuate slots
• CPC Class Codes: A61F 2002/30685 Means for reducing or preventing the generation of wear particulates
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/30948 using computerized tomography, i.e. CT scans
• CPC Class Codes: A61F 2002/30952 using CAD-CAM techniques or NC-techniques
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/4658 for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2310/00017 Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00203 : containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00239 : containing zirconia or zirconium oxide ZrO2
• CPC Class Codes: A61F 2310/00407 : Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: Y10S 623/901 : Method of manufacturing prosthetic device
• CPC Class Codes: Y10T 29/49764 : with testing or indicating

Abstract

A replacement device for resurfacing a joint surface of a femur and a method of making and installing such a device is provided. The custom replacement device is designed to substantially fit the trochlear groove surface, of an individual femur. Thereby creating a “customized” replacement device for that individual femur and maintaining the original kinematics of the joint. The replacement device may be defined by four boundary points, and a first and a second surface. The first of four points is 3 to 5 mm from the point of attachment of the anterior cruciate ligament to the femur. The second point is near the bottom edge of the end of the natural articulatar cartilage. The third point is at the top ridge of the right condyle and the fourth point at the top ridge of the left condyle of the femur. The top surface is designed so as to maintain centrally directed tracking of the patella perpendicular to the plane established by the distal end of the femoral condyles and aligned with the center of the femoral head.

Claims

1. A custom-made replacement device for resurfacing the distal end of a particular femur having a trochlear groove surface, comprising:

a front surface;

a back surface;

the back surface being substantially custom formed to match and fit the present natural contour of the trochlear groove surface of the particular femur; and

the front surface substantially tracking the trochlear groove of the femur.

2. The replacement device of claim 1, wherein the replacement device is further defined by a first boundary condition, the first boundary condition being approximately 3 mm to 5 mm from an attachment of an anterior cruciate ligament to the femur.

3. The replacement device of claim 1, wherein the replacement device is further defined by a second boundary condition, the second boundary condition being approximately at least near the superior edge of an end of a natural cartilage of the femur.

4. The replacement device of claim 1, wherein the replacement device is further defined by a third boundary conditions, the third boundary condition being approximately at the top ridge of a right condyle of the femur.

5. The replacement device of claim 1, wherein the replacement device is further defined by a fourth boundary condition, the fourth boundary condition being approximately at the top ridge of a left condyle of the femur.

6. The replacement device of claim 1, wherein the replacement device has a thickness between the front surface and the back surface, the thickness varying approximately between 2 mm to 6 mm.

7. The replacement device of claim 1, further including at least one pin protruding from the back surface of the replacement device adapted to insert into an opening in the distal anterior surface of the femur.

8. The replacement device of claim 1, further including means for coupling the back surface of the replacement device to the trochlear groove surface of the femur.

9. The replacement device of claim 1, wherein the front surface has the tracking of the trochlear groove of the femur that is approximately perpendicular to ends of the condyles of the femur.

10. The replacement device of claim 1, replacement device has substantially an oval shape.

11. The replacement device of claim 1, wherein the replacement device has outer edges, wherein the outer edges of the replacement device are substantially smooth, wherein the trochlear groove radius is approximately 25 mm.