Method of Designing and Manufacturing Artificial Joint Stem with Use of Composite Material

• US 20080234833A1
• Filed: 03/23/2004
• Published: 09/25/2008
• Est. Priority Date: 03/23/2004
• Status: Abandoned Application

• Current Assignee: BI Tec Limited
• Original Assignee: BI Tec Limited
• Inventors: Bandoh, Shunichi, Zako, Masaru
• Application Number:
  US10/599,182
• Publication Number:
  US 20080234833A1
• Time in Patent Office: Days
• US Class Current: 623/23.15
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2/3676 Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30112 Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30136 undulated or wavy, e.g. serpentine-shaped or zigzag-shaped
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30322 differing in surface structures
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30828 parallel
• CPC Class Codes: A61F 2002/30878 with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30929 : having at least two superposed coatings
• 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 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3631 : with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2230/0004 : Rounded shapes, e.g. with rounded corners
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2250/0014 : having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2250/0026 : differing in surface structures

Abstract

The method of designing and manufacturing the artificial joint stem, comprising steps of performing analysis of the internal stress of the artificial joint stem and bone and the adhesive stress of the artificial stem and bone, using the computer, based on the three dimension data indicating the structure of the bone formed by using plural tomographic images of the bone, the design condition involving the form and stiffness of the artificial joint stem configured by using at least one of the tomographic images and the three dimension data, wherein if the result of the analysis does not satisfy the design condition, the condition is changed to have the computer reanalyze and if the result of the analysis satisfies the design condition, the artificial joint stem is designed and manufactured with the stem data based on the result of analysis and the design condition.

Claims

1. A method of designing and manufacturing an artificial joint stem with the use of a composite material comprising:

a first external layer, which is inserted and fixed in an insertion hole formed in a bone without filling cement, torsional stiffness thereof is increased as contacting an internal surface of said insertion hole;

a main structure layer, which is positioned in an inner side than said first external layer, bending stiffness thereof is increased;

a core layer with lower stiffness than the main structure layer and the first external layer, which is positioned in an inner side than said main structure layer; and

a most inner layer, which is positioned between the core layer and the main structure layer;

steps of performing, as using a computer, an analysis involving an internal stress of said artificial joint stem and an adhesive stress of said artificial joint stem and the bone based on three dimension data indicating a structure of said bone made by using plural bone tomographic images and a design condition involving a form and stiffness of said artificial joint stem configured at least by one of said tomographic images and said three dimension image;

having said computer to reanalyze as changing said design condition if a result of said analysis fails to satisfy said design condition;

designing and manufacturing said artificial joint stem using stem data based on said result of said analysis and said design condition if said result of said analysis satisfies said design condition.

2. The method of designing and manufacturing the artificial joint stem with use composite materials according to claim 1, further comprising step of performing analysis including the internal stress of the bone analysis using the finite element.

3. The method of designing and manufacturing the artificial joint stem which uses composite materials according to claim 2, wherein said tomographic image is a tomographic image which is obtained by different transmission speed of the layers of the bone, and further comprising a step of analyzing the internal stress of the bone as determining the Young'"'"'s modulus and the density of every element of the bone based on the relation of the predetermined density and Young'"'"'s modulus of the bone and the transmission speed.

4. The method of designing and manufacturing artificial joint stem which uses composite materials according to claim 1, further comprising a step of forming as superposing the composite materials of the first external layer, the main structure layer, and the core layer by molding in a die.

5. The method of designing and manufacturing artificial joint stem which uses the composite materials according to claim 1, further comprising a step of forming a model of said artificial joint stem or a forming die.

6. The method of designing and manufacturing artificial joint stem which uses the composite materials according to claim 1, further comprising a step of obtaining a material of the composite materials for the use in forming said artificial joint stem as controlling an automatic cutter based on the stem data.

7. The method of designing and manufacturing artificial joint stem which uses the composite materials according to claim 1, further comprising a step of displaying a lamination layer position of the composite materials used in forming said artificial joint stem in a forming die of said artificial joint stem based on the stem data.