Method and system for improving the effectiveness of artificial joints by the application of gas cluster ion beam technology

• US 6,863,786 B2
• Filed: 05/09/2002
• Issued: 03/08/2005
• Est. Priority Date: 05/09/2001
• Status: Active Grant

• Current Assignee: Exogenesis Corporation
• Original Assignee: Exogenesis Biomedical Technology
• Inventors: Blinn, Stephen M., Zide, Barry M., DiFilippo, Vincent
• Primary Examiner(s): VERSTEEG, STEVEN H
• Application Number:
  US10/142,137
• Publication Number:
  US 20030009233A1
• Time in Patent Office: 1,034 Days
• Field of Search: 204/192.34, 204/298.36, 118/723.CB, 216/66, 156/345.3, 156/345.39, 156/345.4
• US Class Current: 204/192.34
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2002/30673 Lubricating means, e.g. synovial pocket
• CPC Class Codes: A61F 2002/30685 Means for reducing or preventing the generation of wear particulates
• CPC Class Codes: A61F 2002/30934 Special articulating surfaces
• CPC Class Codes: A61F 2002/3611 Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: C23C 14/048 using irradiation by energy or particles
• CPC Class Codes: C23C 14/48 Ion implantation
• CPC Class Codes: H01J 2237/0812 Ionized cluster beam [ICB] sources
• CPC Class Codes: H01J 37/317 for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation H01J37/36 takes precedence

Abstract

Regardless of the materials used in an artificial joint component design, the present invention applies gas cluster ion beam (GCIB) technology in order to modify the component'"'"'s surface(s) so as to increase lubrication between contact surfaces, thereby substantially reducing wear debris, osteolysis complications, and accelerated wear failure. The approach of the surface modification comprises an atomic level surface patterning utilizing GCIB to apply a predetermined pattern to the surface(s) of the joint implant to reduce frictional wear at the interface of the surfaces. A reduction in wear debris by GCIB patterning on any surface(s) of a joint prosthesis reduces accelerated failure due to wear and osteolysis and results in a substantial cost savings to the healthcare system, and reduces patient pain and suffering.

Claims

1. A method for modifying a surface of an artificial joint component by gas cluster ion beam processing comprising the steps of:

forming an gas cluster ion beam in a vacuum chamber;

accelerating the gas cluster ion beam;

positioning the surface in the vacuum chamber in the path of the gas cluster ion beam for processing; and

non-uniformly irradiating the surface with the gas cluster ion beam to form a pattern in the surface.

2. The method of claim 1 wherein the pattern comprises height variations for retaining a lubricant.

3. The method of claim 2 wherein the lubricant is a body fluid.

4. The method of claim 1 wherein a mask is placed on or in proximity to the surface during the irradiation step to control irradiation patterning, the mask having apertures, thickness variations, or a combination thereof forming a pattern thereon affecting surface modification by the gas cluster ion beam irradiation.

5. The method of claim 4 wherein the mask is a metal foil or film.

6. The method of claim 1 further comprising the step of:

focusing or collimating the gas cluster ion beam to a predetermined small diameter; and

wherein the non-uniform irradiation step is performed by controllably positioning the surface relative to the small diameter gas cluster ion beam.