Prosthetic knee joint having at least one diamond articulation surface

• US 7,077,867 B1
• Filed: 01/30/2000
• Issued: 07/18/2006
• Est. Priority Date: 08/12/1994
• Status: Expired due to Term

• Current Assignee: Diamicron, Inc.
• Original Assignee: Diamicron, Inc.
• Inventors: Vail, Michael A., Taylor, Jeffrey K., Pope, Bill J., Dixon, Richard H., Jensen, Kenneth M.
• Primary Examiner(s): Isabella, David J.
• Application Number:
  US09/494,278
• Time in Patent Office: 2,361 Days
• Field of Search: 623/18.11, 623/20.14, 623/20.32, 623/20.35, 623/22.11, 623/20.36, 623/23.39, 623/11.11, 623/16.11, 623/22.4, 623/23.11, 623/23.38, 623/23.53, 427554-556, 427/248.1, 427/249, 512/93, 512/95
• US Class Current: 623/20.14
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• 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 2/3099 for temporo-mandibular [TM, TMJ] joints endoprostheses for mandibular reconstruction A61F2/2803
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/3609 Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts A61F2/3601 takes precedence
• 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 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3804 for elbows
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/3868 with sliding tibial bearing
• CPC Class Codes: A61F 2/3877 Patellae or trochleae
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4059 Humeral shafts
• CPC Class Codes: A61F 2/4081 Glenoid components, e.g. cups
• CPC Class Codes: A61F 2/4241 for hands, e.g. fingers
• CPC Class Codes: A61F 2/4261 for wrists
• CPC Class Codes: A61F 2/442 : Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• 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 2002/30084 : Materials having a crystalline structure
• CPC Class Codes: A61F 2002/30149 : pentagonal
• CPC Class Codes: A61F 2002/30301 : saddle-shaped
• CPC Class Codes: A61F 2002/30332 : Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30339 : Double cones, i.e. connecting element having two conical connections, one at each of its opposite ends
• CPC Class Codes: A61F 2002/30364 : Rotation about the common longitudinal axis
• CPC Class Codes: A61F 2002/30398 : Sliding
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30462 : retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2002/3081 : inclined obliquely with respect to each other
• 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 2002/30894 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30922 : Hardened surfaces
• CPC Class Codes: A61F 2002/30934 : Special articulating surfaces
• CPC Class Codes: A61F 2002/30968 : Sintering
• CPC Class Codes: A61F 2002/30973 : Two joined adjacent layers having complementary interlocking protrusions and recesses
• CPC Class Codes: A61F 2002/3241 : having a ring, e.g. for locking the femoral head into the acetabular cup
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/3652 : Connections of necks to shafts
• CPC Class Codes: A61F 2002/3674 : Connections of proximal parts to distal parts
• CPC Class Codes: A61F 2002/3895 : unicompartimental
• CPC Class Codes: A61F 2002/4051 : Connections of heads directly to shafts
• CPC Class Codes: A61F 2002/4062 : Proximal or metaphyseal parts of shafts
• CPC Class Codes: A61F 2002/4077 : Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0075 : sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0095 : Saddle-shaped
• 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 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 2310/00065 : Manganese or Mn-based alloys
• CPC Class Codes: A61F 2310/00095 : Niobium or Nb-based alloys
• CPC Class Codes: A61F 2310/00131 : Tantalum or Ta-based alloys
• CPC Class Codes: A61F 2310/00149 : Platinum or Pt-based alloys
• CPC Class Codes: A61F 2310/00281 : containing silicon carbide
• CPC Class Codes: A61F 2310/0058 : Coating made of diamond or of diamond-like carbon DLC
• CPC Class Codes: A61L 27/04 : Metals or alloys
• CPC Class Codes: A61L 27/08 : Carbon ; Graphite
• CPC Class Codes: A61L 27/303 : Carbon
• CPC Class Codes: B22F 2207/01 : Composition gradients
• CPC Class Codes: B22F 2998/00 : Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 : Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 : Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/1021 : Removal of binder or filler removal of binder from ceramics C04B35/638
• CPC Class Codes: B22F 3/1216 : Container composition
• CPC Class Codes: B22F 3/14 : simultaneously
• CPC Class Codes: B22F 3/24 : After-treatment of workpieces or articles B22F3/1146 takes precedence
• CPC Class Codes: B22F 7/06 : of composite workpieces or articles from parts, e.g. to form tipped tools B22F7/002 takes precedence
• CPC Class Codes: C22C 26/00 : Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
• CPC Class Codes: C23C 14/0611 : Diamond
• CPC Class Codes: C23C 16/27 : Diamond only
• CPC Class Codes: F16C 33/12 : Structural composition; Use of special materials or surface treatments, e.g. for rust-proofing

Abstract

Prosthetic joints, components for prosthetic joints, superhard bearing and articulation surfaces, diamond bearing and articulation surfaces, substrate surface topographical features, materials for making joints, bearing and articulation surfaces, and methods for manufacturing and finishing the same, and related information are disclosed, including prosthetic knee joint having at least one diamond articulation surface.

Claims

1. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion,

a first joint member polycrystalline diamond compact, said first joint member polycrystalline diamond compact serving to form at least a portion of said first joint member load bearing and articulation portion,

a first joint member polycrystalline diamond compact substrate, said substrate being located on said first joint member polycrystalline diamond compact,

a first joint member polycrystalline diamond compact diamond table sintered to said first joint member polycrystalline diamond compact substrate,

solvent-catalyst metal located in said first joint member polycrystalline diamond compact,

a first joint member gradient transition zone between said first joint member polycrystalline diamond compact substrate and said first joint member polycrystalline diamond compact diamond table, said first joint member gradient transition zone having a substrate side and a diamond table side, said first joint member gradient transition zone having both solvent-catalyst metal and diamond therein, and said first joint member gradient transition zone exhibiting a transition of ratios of percentage content of solvent catalyst metal to diamond from one side of said gradient transition zone to another side such that at a first point in said first joint member gradient transition zone near said substrate side, the ratio of percentage content of solvent-catalyst metal to diamond is greater than it is at a second point in said first joint member gradient transition zone closer to said diamond side than said first point,

chemical bonds between said first joint member polycrystalline diamond compact diamond table and said first joint member polycrystalline diamond compact substrate which tend to secure said diamond table to said substrate,

a mechanical grip between said first joint member polycrystalline diamond compact diamond table and said first joint member polycrystalline diamond compact substrate which tends to secure said diamond table to said substrate,

a first joint member load bearing and articulation surface, said first joint member load bearing and articulation surface including sintered polycrystalline diamond of said first joint member polycrystalline diamond compact, said sintered polycrystal line diamond providing a smooth and low-friction first joint member load bearing and articulation surface,

a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact, said second joint member polycrystalline diamond compact serving to form at least a portion of said second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact substrate, said substrate being located on said second joint member polycrystalline diamond compact,

a second joint member polycrystalline diamond compact diamond table sintered to said second joint member polycrystalline diamond compact substrate, solvent-catalyst metal located in said second joint member polycrystalline diamond compact,

a second joint member gradient transition zone between said second joint member polycrystalline diamond compact substrate and said second joint member polycrystalline diamond compact diamond table, said second joint member gradient transition zone

having a substrate side and a diamond table side, said second joint member gradient transition zone having both solvent-catalyst metal and diamond therein, and said second joint member gradient transition zone exhibiting a transition of ratios of percentage content of solvent-catalyst metal to diamond from one side of said gradient transition zone to another side such that at a first point in said second joint member gradient transition zone near said substrate side, the ratio of percentage content of solvent-catalyst metal to diamond is greater than it is at a second point in said second joint member gradient transition zone closer to said diamond side than said first point,

chemical bonds between said second joint member polycrystalline diamond compact diamond table and said second joint member polycrystalline diamond compact substrate which tend to secure said diamond table to said substrate,

a mechanical grip between said second joint member polycrystalline diamond compact diamond table and said second joint member polycrystalline diamond compact substrate which tends to secure said diamond table to said substrate, and

a second joint member load bearing and articulation surface, said second joint member load bearing and articulation surface including sintered polycrystalline diamond of said second joint member polycrystalline diamond compact, said sintered polycrystalline diamond providing a smooth and low-friction second joint member load bearing and articulation surface.

2. A joint as recited in claim 1 further comprising topographical features on at least one of said substrates, said topographical features serving to enhance said mechanical grip between the substrate and its corresponding diamond table.

3. A joint as recited in claim 1 wherein said first joint member load bearing and articulation surface has a convex shape and wherein said second joint member load bearing and articulation surface has a concave shape.

4. A joint as recited in claim 1 wherein at least one of said first and said second joint member load bearing and articulation surface has an arcuate shape.

5. A joint as recited in claim 1 wherein at least one of said first and said second joint member load bearing and articulation surface has a hemispherical shape.

6. A joint as recited in claim 1 further comprising an interface present between at least one of said substrates and its diamond table.

7. A joint as recited in claim 1 further comprising solvent-catalyst metal present in said substrate.

8. A joint as recited in claim 7 wherein said solvent-catalyst metal present in said substrate is the same solvent-catalyst metal present in said diamond table.

9. A joint as recited in claim 1 further comprising interstitial spaces in at least one of said diamond tables.

10. A joint as recited in claim 1 further comprising solvent-catalyst metal located in at least one of said diamond tables.

11. A joint as recited in claim 1 further comprising a residual stress field in at least one of said polycrystalline diamond compacts, said residual stress field tending to enhance strength of said polycrystalline diamond compact.

12. A joint as recited in claim 1 wherein diamond in at least one of said polycrystalline diamond compacts has a coefficient of thermal expansion CTE_Cd, and wherein its corresponding substrate has a coefficient of thermal expansion CTE_sub, and wherein CTE_Cd is not equal to CTE_sub.

13. A joint as recited in claim 1 wherein in at least one of said polycrystalline diamond compacts, the diamond has a modulus M_Cd, and the substrate has a modulus M_sub, and wherein M_Cd, is not equal to M_sub.

14. A joint as recited in claim 1 further comprising a crystalline diamond structure in at least one of said diamond tables.

15. A joint as recited in claim 1 wherein at least one of said load bearing and articulation surfaces has an Ra value of between about 0.01 to about 0.005 microns.

16. A joint as recited in claim 1 wherein at least one of said polycrystalline diamond load bearing and articulation surfaces is burnished.

17. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions is shaped to be press fit into a receptacle formed in a bone.

18. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior.

19. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior that includes features which enhance frictional engagement with a bone.

20. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior that permits osseointegration.

21. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior that includes a surface coating which encourages bone growth against said coating.

22. A joint as recited in claim 1 further comprising a bone mating surface on at least a portion the joint, said bone mating surface including a structure selected from the group consisting of metal mesh, porous metal, porous diamond, metal sintered beads, and plasma spray metal.

23. A joint as recited in claim 1 wherein at least one of said first and said second joint member bone fixation portions is shaped to permit bone fixation to be accomplished by use of at least one mechanical fastener.

24. A joint as recited in claim 1 wherein at least one of said substrates includes a metal alloy with at least one component of said metal alloy being selected from the group consisting of titanium, aluminum, vanadium, molybdenum, hafnium, nitinol, cobalt, chrome, molybdenum, tungsten, cemented tungsten carbide, cemented chrome carbide, fused silicon carbide, nickel, tantalum, and stainless steel.

25. A joint as recited in claim 1 wherein at least one of said substrates includes CoCr as a solvent-catalyst metal.

26. A joint as recited in claim 1 wherein at least one of said substrates includes a plurality of substrate layers.

27. A joint as recited in claim 1 wherein at least one of said substrates includes at least two distinct substrate layers of different metals.

28. A joint as recited in claim 1 wherein at least one of said diamond tables includes diamond crystals of at least two different dimensions.

29. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact, said second joint member polycrystalline diamond compact serving to form at least a portion of said second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact substrate, said substrate being located on said second joint member polycrystalline diamond compact,

a second joint member polycrystalline diamond compact diamond table sintered to said second joint member polycrystalline diamond compact substrate, solvent-catalyst metal located in said second joint member polycrystalline diamond compact,

a second joint member gradient transition zone between said second joint member polycrystalline diamond compact substrate and said second joint member polycrystalline diamond compact diamond table, and

a second joint member load bearing and articulation surface, said second joint member load bearing and articulation surface including sintered polycrystalline diamond, said sintered polycrystalline diamond providing a smooth and low-friction second joint member load bearing and articulation surface,

having solvent-catalyst metal located in said second joint member polycrystalline diamond compact.

30. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact, said second joint member polycrystalline diamond compact serving to form at least a portion of said second joint member load bearing and articulation portion, said second joint member polycrystalline diamond compact having solvent-catalyst metal located within it,

a second joint member polycrystalline diamond compact substrate, said substrate being located on said second joint member polycrystalline diamond compact,

a second joint member polycrystalline diamond compact diamond table sintered to said second joint member polycrystalline diamond compact substrate, solvent-catalyst metal located in said second joint member polycrystalline diamond compact,

a second joint member gradient transition zone between said second joint member polycrystalline diamond compact substrate and said second joint member polycrystalline diamond compact diamond table,

wherein said second joint member gradient transition zone has a substrate side and a diamond table side, said second joint member gradient transition zone having both solvent-catalyst metal and diamond therein, and said second joint member gradient transition zone exhibiting a transition of ratios of percentage content of solvent-catalyst metal to diamond from one side of said gradient transition zone to another side such that at a first point in said second joint member gradient transition zone near said substrate side, the ratio of percentage content of solvent-catalyst metal to diamond is greater than it is at a second point in said second joint member gradient transition zone closer to said diamond side than said first point, and

a second joint member load bearing and articulation surface, said second joint member load bearing and articulation surface including sintered polycrystalline diamond, said sintered polycrystalline diamond providing a smooth and low-friction second joint member load bearing and articulation surface.

31. A joint as recited in claim 30 further comprising chemical bonds between said second joint member polycrystalline diamond compact diamond table and said second joint member polycrystalling diamond compact substrate which tend to secure said diamond table to said substrate.

32. A joint as recited in claim 30 further comprising a mechanical grip between said second joint member polycrystalline diamond compact diamond table and said second joint member polycrystalline diamond compact substrate which tends to secure said diamond table to said substrate.

33. A joint as recited in claim 32 further comprising topographical features on at least one of said substrates, said topographical features serving to enhance said mechanical grip between the substrate and its corresponding diamond table.

34. A joint as recited in claim 30 wherein said second joint member load bearing and articulation surface has a shape selected from the group consisting of concave, convex, arcuate, hemispherical and partially spherical.

35. A joint as recited in claim 30 further comprising a residual stress field in said polycrystalline diamond compact, said residual stress field tending to enhance the strength of said polycrystalline diamond compact.

36. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact, said second joint member polycrystalline diamond compact serving to form at least a portion of said second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact substrate, said substrate being located on said second joint member polycrystalline diamond compact,

a second joint member polycrystalline diamond compact diamond table sintered to said second joint member polycrystalline diamond compact substrate, solvent-catalyst metal located in said second joint member polycrystalline diamond compact,

a second joint member gradient transition zone between said second joint member polycrystalline diamond compact substrate and said second joint member polycrystalline diamond compact diamond table, and

a second joint member load bearing and articulation surface, said second joint member load bearing and articulation surface including sintered polycrystalline diamond, said sintered polycrystalline diamond providing a smooth and low-friction second, joint member load bearing and articulation surface, and

wherein diamond in said polycrystalline diamond compact has a coefficient of thermal expansion CTE_Cd, and wherein said corresponding substrate has a coefficient of thermal expansion CTE_sub, and wherein CTE_Cd is not equal to CTE_sub.

37. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact, said second joint member polycrystalline diamond compact serving to form at least a portion of said second joint member load bearing and articulation portion,

a second joint member polycrystalline diamond compact substrate, said substrate being located on said second joint member polycrystalline diamond compact,

a second joint member polycrystalline diamond compact diamond table sintered to said second joint member polycrystalline diamond compact substrate, solvent-catalyst metal located in said second joint member polycrystalline diamond compact,

a second joint member gradient transition zone between said second point member polycrystalline diamond compact substrate and said second joint member polycrystalline diamond compact diamond table, and

a second joint member load bearing and articulation surface, said second joint member load bearing and articulation surface including sintered polycrystalline diamond, said sintered polycrystalline diamond providing a smooth and low-friction second joint member load bearing and articulation surface, and

wherein in said polycrystalline diamond compact, the diamond has a modulus M_Cd, and the substrate has a modulus M_sub, and wherein M_Cd is not equal to M_sub.

38. A joint as recited in claim 37 wherein said second joint member load bearing and articulation surface has an Ra value of between about 0.01 to about 0.005 microns.

39. A joint as recited in claim 37 wherein said polycrystalline diamond load bearing and articulation surface is burnished.

40. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions is shaped to be press fit into a receptacle formed in a bone.

41. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior.

42. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior that includes features which enhance frictional engagement with a bone.

43. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior, said bone mating surface including a structure selected from the group consisting of metal mesh, porous metal, porous diamond, metal sintered beads, and plasma spray metal.

44. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions includes a bone mating surface on at least a portion of its exterior that includes a surface coating which encourages bone growth against said coating.

45. A joint as recited in claim 44 wherein said coating includes hydroxyl apatite.

46. A joint as recited in claim 37 wherein at least one of said first and said second joint member bone fixation portions is shaped to permit bone fixation to be accomplished by use of at least one mechanical fastener.

47. A joint as recited in claim 37 wherein said substrate includes at least one metal selected from the group consisting of cobalt, chrome, titanium, tungsten, molybdenum and iron.

48. A joint as recited in claim 37 wherein said substrate includes a metal alloy selected from the group consisting of titanium, titanium aluminum and vanadium, titanium molybdenum hafnium, titanium and nitinol, cobalt chrome, cobalt chrome molybdenum, cobalt chrome tungsten, cobalt chrome cemented tungsten carbide, cobalt chrome cemented chrome carbide, fused silicon carbide and stainless steel.

49. A joint as recited in claim 37 wherein said substrate includes a plurality of substrate layers.

50. A joint as recited in claim 37 wherein said substrate includes at least two distinct substrate layers of different metals.

51. A joint as recited in claim 37 wherein said diamond table includes diamond crystals of at least two different dimensions.

52. A joint as recited in claim 37 further comprising a first joint member load bearing and articulation surface, said first joint member load bearing and articulation surface including a counter bearing material against which said second joint member load bearing and articulation surface polycrystalline diamond may articulate.

53. A joint as recited in claim 52 wherein said counter bearing material includes a material selected from the group consisting of monocrystal diamond, natural diamond, polycrystalline diamond, CVD diamond, PVD diamond, cubic boron nitride, wurzitic boron nitride, ceramic, cobalt-chrome alloy, titanium alloy, nickel, vanadium, tantalum, hafnium, molybdenum, cemented tungsten carbide, niobium, zirconia ceramic, alumina ceramic, polymers, UHMWPE, PEEK, cross-linked polymers and sapphire.

54. A joint as recited in claim 37 wherein said first joint member load bearing and articulation surface counter bearing material is not as hard as said second joint member load bearing and articulation surface.

55. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a load bearing and articulation surface located on said second joint member load bearing and articulation portion,

a volume of diamond located on said load bearing and articulation portion, said volume of diamond material forming at least a portion of said load bearing and articulation surface,

wherein polycrystalline diamond is present in said volume of diamond, and

wherein said polycrystalline diamond has a coefficient of thermal expansion CTE_Cd and said substrate has a coefficient of thermal expansion CTE_sub, and wherein CTE_Cd is not equal to CTE_sub.

56. A joint as recited in claim 55 said volume of diamond comprises polycrystalline diamond and wherein said second joint member load bearing and articulation portion comprises a substrate to which said polycrystalline diamond is sintered.

57. A joint as recited in claim 56 further comprising a gradient transition zone between polycrystalline diamond and said substrate.

58. A joint as recited in claim 57 further comprising chemical bonds between said polycrystalline diamond and said substrate.

59. A joint as recited in claim 58 further comprising a mechanical grip between said polycrystalline diamond and said substrate.

60. A joint as recited in claim 59 further comprising topographical features on said substrate, said topographical features serving to enhance said mechanical grip between said substrate and said polycrystalline diamond.

61. A joint as recited in claim 58 wherein said polycrystalline diamond and said substrate comprise a polycrystalline diamond compact.

62. A joint as recited in claim 61 further comprising a residual stress field in said polycrystalline diamond compact, said residual stress field tending to enhance strength of said polycrystalline diamond compact.

65. A joint as recited in claim 55 wherein said diamond articulation surface has an Ra value of between about 0.5 to about 0.005 microns.

66. A joint as recited in claim 55 wherein said diamond is selected from the group consisting of natural diamond, monocrystal diamond, polycrystalline diamond, CVD diamond and PVD diamond.

63. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a load bearing and articulation surface located on said second joint member load bearing and articulation portion, and

a volume of diamond located on said load bearing and articulation portion, said volume of diamond material forming at least a portion of said load bearing and articulation surface,

said volume of diamond comprises polycrystalline diamond and wherein said second joint member load bearing and articulation portion comprises a substrate to which said polycrystalline diamond is sintered,

a gradient transition zone between polycrystalline diamond and said substrate, having chemical bonds between said polycrystalline diamond and said substrate,

wherein said polycrystalline diamond and said substrate comprise a polycrystalline diamond compact,

a residual stress field in said polycrystalline diamond compact, said residual stress field tending to enhance strength of said polycrystalline diamond compact, and

wherein said polycrystalline diamond has a coefficient of thermal expansion CTE_Cd, and said substrate has a coefficient of thermal expansion CTE_sub, and wherein CTE_cd is not equal to CTE_sub.

64. A prosthetic knee joint comprising:

a first joint member,

a first joint member bone fixation portion, said first joint member bone fixation portion being adapted to be securable to a bone,

a first joint member load bearing and articulation portion, a second joint member,

a second joint member bone fixation portion, said second joint member bone fixation portion being adapted to be securable to a bone,

a second joint member load bearing and articulation portion,

a load bearing and articulation surface located on said second joint member load bearing and articulation portion, and

a volume of diamond located on said load bearing and articulation portion, said volume of diamond material forming at least a portion of said load bearing and articulation surface,

said volume of diamond comprises polycrystalline diamond and wherein said second joint member load bearing and articulation portion comprises a substrate to which said polycrystalline diamond is sintered,

a gradient transition zone between polycrystalline diamond and said substrate, having chemical bonds between said polycrystalline diamond and said substrate,

wherein said polycrystalline diamond and said substrate comprise a polycrystalline diamond compact,

a residual stress field in said polycrystalline diamond compact, said residual stress field tending to enhance strength of said polycrystalline diamond compact,

wherein said polycrystalline diamond has a coefficient of thermal expansion CTE_Cd and said substrate has a coefficient of thermal expansion CTE_sub, and wherein CTE_Cd is not equal to CTE_sub, and

wherein in said polycrystalline diamond has a modulus MCd, and said substrate has a modulus Msub, and wherein MCd, is not equal to Msub.