Assessing the condition of a joint and devising treatment

• US 8,036,729 B2
• Filed: 01/22/2004
• Issued: 10/11/2011
• Est. Priority Date: 09/14/1998
• Status: Expired due to Term

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Lang, Philipp, Steines, Daniel
• Primary Examiner(s): Casler; Brian
• Assistant Examiner(s): CWERN, JONATHAN
• Application Number:
  US10/764,010
• Publication Number:
  US 20040167390A1
• Time in Patent Office: 2,819 Days
• Field of Search: 382/128, 345/420, 600/407, 600/416, 600/427, 623/18.11
• US Class Current: 600/407
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/103 Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes A61B5/08 takes precedence; measuring aids for tailors A41H1/00; measuring instruments specially adapted for dentistry A61C19/04
• CPC Class Codes: A61B 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/112 Gait analysis
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/1122 of movement trajectories
• CPC Class Codes: A61B 5/1127 using markers
• CPC Class Codes: A61B 5/4514 Cartilage
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: G09B 23/30 Anatomical models G09B23/281 - G09B23/288 take precedence

Abstract

Methods are disclosed for assessing the condition of a cartilage in a joint, particularly a human knee. The methods include converting an image such as an MRI to a three dimensional map of the cartilage. The cartilage map can be correlated to a movement pattern of the joint to assess the affect of movement on cartilage wear. Changes in the thickness of cartilage over time can be determined so that therapies can be provided. Information on thickness of cartilage and curvature of cartilage or subchondral bone can be used to plan therapy. Information on movement pattern can be used to plan therapy.

Claims

1. A method of creating an implant for treating joint disease, which method comprises:

obtaining from image data of a damaged or diseased joint information about the three-dimensional geometry of the joint, including at least one of normal articular cartilage, diseased articular cartilage, and subchondral bone;

creating a three-dimensional electronic model of at least a portion of the joint including at least one of normal articular cartilage, diseased articular cartilage, and subchondral bone, wherein the model includes a geometry of at least a portion of an articular surface of the joint; and

creating an implant based on the three-dimensional model, wherein at least a portion of said implant has an outer articular surface derived from the geometry of at least a portion of the articular surface of the joint.

2. The method of claim 1, wherein said image data is ultrasound data, computed tomography data, positron emission tomography data, a single photon emission computed tomography scan, or MRI data.

3. The method of claim 1, wherein said implant is configured to repair an area of said diseased articular cartilage as well as adjacent normal tissue.

4. The method of claim 3, wherein the adjacent normal tissue is at least one of bone, bone marrow, and normal articular cartilage.

5. The method of claim 1, wherein the implant is configured to repair an area encompassing at least a portion of said diseased articular cartilage.

6. The method of claim 1, wherein the implant is configured to repair an area encompassing at least a portion of said normal articular cartilage.

7. The method of claim 1, wherein the implant is created with use of a 3D Euclidian distance transform.

8. The method of claim 1, wherein at least a portion of said implant is configured to be implantable into a knee joint.

9. The method of claim 1, wherein the implant further comprises cartilage cells or cartilage matrix.

10. The method of claim 1, wherein the three-dimensional electronic model of at least a portion of the joint includes the normal articular cartilage and the diseased articular cartilage in at least one portion of the joint.

11. The method of claim 1, wherein the three-dimensional electronic model of at least a portion of the joint includes the normal articular cartilage adjacent to the diseased articular cartilage in at least one portion of the joint.

12. The method of claim 1, wherein the step of creating an implant further includes creating a thickness of a portion of said implant substantially similar to a thickness of said normal articular cartilage in at least one portion of the joint.

13. The method of claim 1, wherein the step of creating an implant further includes creating a thickness of a portion of said implant that is fixed and substantially similar to a thickness of said normal articular cartilage in at least one portion of the joint.

14. The method of claim 1, wherein the step of creating an implant further includes creating a thickness of a portion of said implant that is substantially similar to a thickness of said normal articular cartilage adjacent to diseased articular cartilage in at least one portion of the joint.

15. The method of claim 1, wherein said implant is configured to be located in at least one of a medial femoral condyle, a lateral femoral condyle, or both femoral condyles of the joint.

16. The method of claim 1, wherein said implant is configured to be located in at least one femoral condyle and the notch region of a joint.

17. The method of claim 1, wherein said implant is configured to be located in at least one of a medial tibial plateau, a lateral tibial plateau, or an entire tibial plateau of the joint.

18. The method of claim 1, wherein said implant is configured to be located in at least one of a medial patella, a lateral patella, an entire patella, or an entire joint.

19. The method of claim 1, wherein said implant is configured based on an isosurface of said subchondral bone.

20. The method of claim 1, wherein said implant is based on polygons.

21. The method of claim 20, wherein said polygons are derived using a tessellation.

22. The method of claim 1, wherein said implant is also based on a contact pattern.

23. The method of claim 22, wherein said contact pattern is derived from static alignment.

24. The method of claim 22, wherein said contact pattern is derived from dynamic loading.

25. The method of claim 24, wherein said dynamic loading is estimated for gait.

26. The method of claim 22, wherein said contact pattern is derived on an image.

27. The method of claim 22, wherein said contact pattern is derived in three dimensions.

28. The method of claim 1, wherein said implant is configured to repair an area encompassing bone or bone marrow.

29. The method of claim 1, wherein said image data undergoes a segmentation.

30. The method of claim 29, wherein said segmentation is used to segment articular cartilage.

31. The method of claim 30, wherein said articular cartilage is normal cartilage.

32. The method of claim 30, wherein said articular cartilage is diseased cartilage.

33. The method of claim 29, wherein said segmentation is used to segment bone.

34. The method of claim 1, wherein said three-dimensional model includes one or more static relationship transformations between a femur and tibia of the joint.

35. The method of claim 1, wherein said three-dimensional model includes at least one sequence of transformations between a femur and tibia of the joint.

36. The method of claim 1, wherein said three-dimensional model is merged with one or more load alignment estimations.

37. The method of claim 36, wherein said one or more load alignment estimations include at least one of load alignment in standing or weight-bearing position, load alignment in lying or non-weight-bearing position, and load alignment during joint motion.

38. The method of claim 1, wherein a thickness of said implant is derived from a thickness of cartilage at an implantation site.

39. The method of claim 1, wherein a curvature of the outer surface of said implant is derived from a curvature of a surface of an implantation site.

40. The method of claim 1, wherein the implant is created by a digital manufacturing method.

41. The method of claim 40, wherein the digital manufacturing method is rapid prototyping.

42. The method of claim 1, wherein the implant is created using a computer aided design system.

43. A method of creating an implant for treating joint disease, which method comprises:

obtaining from image data of a damaged or diseased joint information about the three-dimensional geometry of the joint, wherein the information includes information on a thickness of normal articular cartilage;

creating a three-dimensional electronic model of at least a portion of the joint wherein the model includes a geometry of at least a portion of an articular surface of the joint; and

creating an implant having an outer articular surface, the implant based at least in part on the geometry of the model and a thickness derived at least in part based on the thickness of the normal articular cartilage.

44. The method of claim 43, wherein said image data is ultrasound data, computed tomography data, positron emission tomography data, a single photon emission computed tomography scan, or MRI data.

45. The method of claim 43, wherein said implant is configured to repair an area of diseased articular cartilage as well as adjacent normal tissue.

46. The method of claim 45, wherein said adjacent normal tissue is bone, bone marrow, or normal articular cartilage.

47. The method of claim 43, wherein said implant is created with use of a 3D Euclidian distance transformation.

48. The method of claim 43, wherein at least a portion of said implant is configured to be implantable into a knee joint.

49. The method of claim 43, wherein said implant further comprises cartilage cells or cartilage matrix.

50. The method of claim 43, wherein said implant is also based on a contact pattern.

51. The method of claim 50, wherein said contact pattern is derived from static alignment.

52. The method of claim 50, wherein said contact pattern is derived from dynamic loading.

53. The method of claim 52, wherein said dynamic loading is estimated for gait.

54. The method of claim 50, wherein said contact pattern is derived on an image.

55. The method of claim 50, wherein said contact pattern is derived in three dimensions.

56. The method of claim 43, wherein the implant is configured to repair an area encompassing at least a portion of diseased articular cartilage.

57. The method of claim 43, wherein the implant is configured to repair an area encompassing at least a portion of said normal articular cartilage.

58. The method of claim 43, wherein the three-dimensional electronic model of at least a portion of the joint includes normal and diseased articular cartilage in at least one portion of the joint.

59. The method of claim 43, wherein the three-dimensional electronic model of at least a portion of the joint includes normal articular cartilage adjacent to diseased articular cartilage in at least one portion of the joint.

60. The method of claim 43, wherein the step of creating an implant further comprises creating a thickness of a portion of said implant substantially similar to a thickness of said normal articular cartilage in at least one portion of the joint.

61. The method of claim 43, wherein the step of creating an implant further comprises creating a thickness of a portion of said implant that is fixed and the fixed thickness is substantially similar to a thickness of said normal articular cartilage in at least one portion of the joint.

62. The method of claim 43, wherein the step of creating an implant further comprises creating a thickness of a portion of said implant substantially similar to a thickness of said normal articular cartilage adjacent to diseased articular cartilage in at least one portion of the joint.

63. The method of claim 43, wherein said implant is configured to be located in at least one of a medial femoral condyle, a lateral femoral condyle, or both femoral condyles of the joint.

64. The method of claim 43, wherein said implant is configured to be located in at least one femoral condyle and the notch region of the joint.

65. The method of claim 43, wherein said implant is configured to be located in at least one of a medial tibial plateau, a lateral tibial plateau, or an entire tibial plateau of the joint.

66. The method of claim 43, wherein said implant is configured to be located in at least one of a medial patella, a lateral patella, an entire patella, or an entire joint of the joint.

67. The method of claim 43, wherein said implant is configured to repair an area encompassing bone or bone marrow.

68. The method of claim 43, wherein said image data undergoes a segmentation.

69. The method of claim 68, wherein said segmentation is used to segment articular cartilage.

70. The method of claim 69, wherein said articular cartilage is normal cartilage.

71. The method of claim 69, wherein said articular cartilage is diseased cartilage.

72. The method of claim 68, wherein said segmentation is used to segment bone.

73. The method of claim 43, wherein said three-dimensional model includes one or more static relationship transformations between a femur and tibia of the joint.

74. The method of claim 43, wherein said three-dimensional model includes at least one sequence of transformations between a femur and tibia of the joint.

75. The method of claim 43, wherein said three-dimensional model is merged with one or more load alignment estimations.

76. The method of claim 75, wherein said one or more load alignment estimations include at least one of load alignment in standing or weight-bearing position, load alignment in lying or non-weight-bearing position, and load alignment during joint motion.

77. The method of claim 43, wherein a thickness of said implant is derived from a thickness of cartilage at an implantation site.

78. The method of claim 43, wherein a curvature of the outer surface of said implant is derived from a curvature of a surface of an implantation site.

79. The method of claim 43, wherein said information on the thickness of articular cartilage, including normal and/or diseased cartilage, includes information of articular cartilage defects.

80. The method of claim 79, wherein said obtaining information includes evaluating a region of said articular cartilage defect and contiguous parts of said articular cartilage surrounding said region of said articular cartilage defect.

81. The method of claim 79, wherein said information of articular cartilage defects is used to determine one or more dimensions of said implant.

82. A method of forming a physical model for repairing a joint which method comprises:

obtaining from image data of a damaged or diseased joint information about the three-dimensional geometry of subchondral bone of the joint;

creating a three-dimensional electronic model of the geometry of at least a portion of the joint, including at least a portion of the subchondral bone; and

forming a physical model having an outer articular surface based at least in part on the geometry of the subchondral bone of the three-dimensional electronic model.

83. The method of claim 82, wherein the physical model comprises a bone replacement material.

84. The method of claim 82, wherein at least a portion of the outer surface matches a curvature of the subchondral bone.

85. The method of claim 84, wherein at least a portion of the curvature is a three-dimensional curvature of the subchondral bone.

86. The method of claim 82, wherein at least a portion of the outer surface substantially matches the dimensions of diseased cartilage of the joint in at least one direction.

87. The method of claim 86, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the anteroposterior direction.

88. The method of claim 86, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the mediolateral direction.

89. The method of claim 86, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the superoinferior direction.

90. The method of claim 82, wherein the physical model further comprises an inner surface.

91. The method of claim 90, wherein at least a portion of the inner surface substantially matches the dimensions of diseased cartilage of the joint in at least one direction.

92. The method of claim 91, wherein at least a portion of the inner surface substantially matches the dimensions of the diseased cartilage of the joint in the anteroposterior direction.

93. The method of claim 91, wherein at least a portion of the inner surface substantially matches the dimensions of the diseased cartilage of the joint in the mediolateral direction.

94. A method of creating a device for treating an articular joint, which method comprises:

deriving from image data of a damaged or diseased joint a geometry of at least a portion of a surface of subchondral bone of the joint;

creating a three-dimensional electronic model of the geometry of at least a portion of the joint including the at least a portion of the subchondral bone surface; and

creating a physical model having an outer articular surface configured from at least a portion of the three-dimensional electronic model of the geometry of the surface of the subchondral bone.

95. The method of claim 94, wherein the physical model comprises a bone replacement material.

96. The method of claim 94, wherein at least a portion of the outer surface matches a curvature of the subchondral bone.

97. The method of claim 96, wherein the curvature is a three-dimensional curvature of the subchondral bone.

98. The method of claim 94, wherein at least a portion of the outer surface substantially matches the dimensions of diseased cartilage of the joint in at least one direction.

99. The method of claim 98, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the anteroposterior direction.

100. The method of claim 98, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the mediolateral direction.

101. The method of claim 98, wherein at least a portion of the outer surface substantially matches the dimensions of the diseased cartilage of the joint in the superoinferior direction.

102. The method of claim 94, wherein the physical model further comprises an inner surface.

103. The method of claim 102, wherein at least a portion of the inner surface substantially matches the dimensions of diseased cartilage of the joint in at least one direction.

104. The method of claim 103, wherein at least a portion of the inner surface substantially matches the dimensions of the diseased cartilage of the joint in the anteroposterior direction.

105. The method of claim 103, wherein at least a portion of the inner surface substantially matches the dimensions of the diseased cartilage of the joint in the mediolateral direction.

106. The method of claim 94, wherein the physical model is further based on a geometry of articular cartilage of the joint.

107. The method of claim 94, wherein the physical model is created by a digital manufacturing method.

108. The method of claim 107, wherein the digital manufacturing method is rapid prototyping.

109. The method of claim 94, wherein the physical model is created using a computer aided design system.