SYSTEM AND METHOD FOR MANUFACTURING ARTHROPLASTY JIGS HAVING IMPROVED MATING ACCURACY

• US 20100023015A1
• Filed: 07/17/2009
• Published: 01/28/2010
• Est. Priority Date: 07/23/2008
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Otismed Corporation (Stryker Corporation)
• Inventors: Park, Ilwhan
• Granted Patent: US 8,777,875 B2
• Time in Patent Office: Days
• US Class Current: 606/87
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/157 Cutting tibia
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 17/58 for osteosynthesis, e.g. bone plates, screws , setting implements or the like A61B17/14, A61B17/16 take precedence
• 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

Abstract

Disclosed herein is a method of defining a mating surface in a first side of an arthroplasty jig. The mating surface is configured to matingly receive and contact a corresponding patient surface including at least one of a bone surface and a cartilage surface. The first side is oriented towards the patient surface when the mating surface matingly receives and contacts the patient surface. The method may include: a) identifying a contour line associated with the patient surface as represented in a medical image; b) evaluating via an algorithm the adequacy of the contour line for defining a portion of the mating surface associated with the contour line; c) modifying the contour line if the contour line is deemed inadequate; and d) employing the modified contour line to define the portion of the mating surface associated with the contour line.

Claims

1. A method of defining a mating surface in a first side of an arthroplasty jig, the mating surface configured to matingly receive and contact a corresponding patient surface including at least one of a bone surface and a cartilage surface, the first side being oriented towards the patient surface when the mating surface matingly receives and contacts the patient surface, the method comprising:

a) identifying a contour line associated with the patient surface as represented in a medical image;

b) evaluating via an algorithm the adequacy of the contour line for defining a portion of the mating surface associated with the contour line;

c) modifying the contour line if the contour line is deemed inadequate; and

d) employing the modified contour line to define the portion of the mating surface associated with the contour line.

2. The method of claim 1, wherein step c includes adjusting a portion of the contour line to result in an adjusted contour line portion.

3. The method of claim 2, wherein adjusting a portion of the contour line includes moving the portion of the contour line away from the patient surface.

4. The method of claim 2, wherein step d results in the defining of a surface of the first side that is associated with the adjusted contour line portion and does not contact a corresponding patient surface when the mating surface matingly receives and contacts the patient surface.

5. The method of claim 1, wherein step c includes:

i) adjusting a portion of the contour line to result in an adjusted contour line portion; and

ii) leaving another portion of the contour line unadjusted to result in an unadjusted contour line portion.

6. The method of claim 5, wherein step d results in the defining of:

i) a surface of the first side that is associated with the adjusted contour line portion and does not contact a corresponding patient surface when the mating surface matingly receives and contacts the patient surface; and

ii) a portion of the mating surface that is associated with the unadjusted contour line portion.

7. The method of claim 1, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location to a second characteristic of the contour line at a second location.

8. The method of claim 7, wherein the first characteristic includes a tangent line tangent to the first location and the second characteristic includes a tangent line tangent to the second location.

9. The method of claim 8, wherein the comparison of the first tangent line to the second tangent line includes an evaluation of the angular difference between the two tangent lines.

10. The method of claim 9, wherein a portion of the contour line associated with the first and second tangent lines is inadequate for defining a portion of the mating surface associated with the portion of the contour line if the angular difference between the first and second tangent lines exceeds a selected value.

11. The method of claim 10, wherein the selected value is between approximately 20 degrees and approximately five degrees.

12. The method of claim 10, wherein the selected value is approximately five degrees.

13. The method of claim 7, wherein the first and second locations are respective coordinate points on the contour line.

14. The method of claim 13, wherein the respective coordinate points are immediately adjacent to each other on the contour line.

15. The method of claim 7, wherein the first characteristic includes a first angular relationship associated with the first location and the second characteristic includes a second angular relationship associated with the second location.

16. The method of claim 15, wherein the respective angular relationships are associated with at least one of a tangent line and a normal line extending through the respective locations.

17. The method of claim 1, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location on the contour line to a second characteristic of another contour line at a second location on the another contour line.

18. The method of claim 17, wherein the first characteristic includes a normal line normal to the first location and the second characteristic includes a normal line normal to the second location.

19. The method of claim 18, wherein the comparison of the first normal line to the second normal line includes an evaluation of the angular difference between the two normal lines.

20. The method of claim 19, wherein portions of the contour lines associated with the first and second normal lines are inadequate for defining a portion of the mating surface associated with the portions of the contour lines if the angular difference between the first and second normal lines exceeds a selected set value.

21. The method of claim 20, wherein the selected value is between approximately two degrees and approximately six degrees.

22. The method of claim 20, wherein the selected value is less than approximately two degrees.

23. The method of claim 17, wherein the first and second locations are corresponding points on the two contour lines.

24. The method of claim 23, wherein the two contour lines are immediately adjacent contour lines.

25. The method of claim 17, wherein the first characteristic includes a first angular relationship associated with the first location and the second characteristic includes a second angular relationship associated with the second location.

26. The method of claim 25, wherein the respective angular relationships are associated with at least one of a tangent line and a normal line extending through the respective locations.

27. The method of claim 1, wherein the adequacy evaluation of step b includes comparing an elevational change between a first location on the contour line to a second location on another contour line.

28. The method of claim 27, wherein the first and second locations are first and second points that correspond to each other and the contour line and the another contour line are adjacent to each other.

29. The method of claim 1, wherein the adequacy evaluation of step b includes evaluating an angular value associated with an elevational change between a first point on the contour line to a second point on another contour line.

30. The method of claim 29, wherein the angular value includes an angle between a first line and a second line, wherein the first line extends towards an image slice containing the another contour line from the first point and perpendicular to an image slice containing the contour line, and wherein the second line extends from the first point to the second point.

31. The method of claim 30, wherein portions of the contour lines associated with the first and second points are inadequate for defining a portion of the mating surface associated with the portions of the contour lines if the angle exceeds a selected set value.

32. The method of claim 31, wherein the selected value is between approximately one degree and approximately five degrees.

33. The method of claim 31, wherein the selected value is approximately one degree.

34. The method of claim 1, wherein step b includes evaluating whether at least one of:

i) the contour line will result in the portion of the mating surface associated with the contour line being unlikely to be machined; and

ii) the contour line pertains to a region of the patient surface that is unlikely to be accurately utilized to define the mating surface.

35. The method of claim 1, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location on the contour line to:

a second characteristic of a second contour line at a second location on the second contour line; and

a third characteristic of a third contour line at a third location on the third contour line.

36. The method of claim 35, wherein the first characteristic includes a normal line normal to the first location, the second characteristic includes a normal line normal to the second location, and the third characteristic includes a normal line normal to the third location.

37. The method of claim 36, wherein the comparisons of the first normal line to the second and third normal lines includes an evaluation of the angular differences between the three normal lines.

38. The method of claim 37, wherein portions of the contour lines associated with the first, second and third normal lines are inadequate for defining a portion of the mating surface associated with the portions of the contour lines if the angular differences between the first, second and third normal lines exceeds selected set values.

39. The method of claim 35, wherein the three contour lines are associated with respective adjacent image slices.

40. The method according to claim 1, wherein the adequacy evaluation of step b includes evaluating an angular value associated with:

an elevational change between a first point on the contour line to a second point on a second contour line; and

an elevational change between the second point on the second contour line to a third point on a third contour line.

41. The method of claim 1, wherein the adequacy evaluation of step b includes:

comparing a characteristic of the contour line at a first location to a characteristic of the contour line at a second location; and

comparing another characteristic of the contour line at the first location on the contour line to a characteristic of another contour line at a location on the another contour line.

42. An arthroplasty jig for assisting in the performance of an arthroplasty procedure associated with a patient surface including at least one of a bone surface and a cartilage surface, the jig comprising:

a first side;

a second side generally opposite the first side; and

a mating surface in the first side and configured to matingly receive and contact at least a portion of the patient surface,

wherein the first side is configured to be oriented towards the patient surface when the mating surface matingly receives and contacts the patient surface,

wherein the mating surface is defined according to the following process steps;

a) identifying a contour line associated with the patient surface as represented in a medical image;

b) evaluating via an algorithm the adequacy of the contour line for defining a portion of the mating surface associated with the contour line;

c) modifying the contour line if the contour line is deemed inadequate; and

d) employing the modified contour line to define the portion of the mating surface associated with the contour line.

43. The arthroplasty jig of claim 42, wherein step c includes adjusting a portion of the contour line to result in an adjusted contour line portion.

44. The arthroplasty jig of claim 43, wherein step d results in the defining of a surface of the first side that is associated with the adjusted contour line portion and does not contact a corresponding patient surface when the mating surface matingly receives and contacts the patient surface.

45. The arthroplasty jig of claim 42, wherein step c includes:

i) adjusting a portion of the contour line to result in an adjusted contour line portion; and

ii) leaving another portion of the contour line unadjusted to result in an unadjusted contour line portion.

46. The arthroplasty jig of claim 45, wherein step d results in the defining of:

i) a surface of the first side that is associated with the adjusted contour line portion and does not contact a corresponding patient surface when the mating surface matingly receives and contacts the patient surface; and

ii) a portion of the mating surface that is associated with the unadjusted contour line portion.

47. The arthroplasty jig of claim 42, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location to a second characteristic of the contour line at a second location.

48. The arthroplasty jig of claim 42, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location on the contour line to a second characteristic of another contour line at a second location on the another contour line.

49. The arthroplasty jig of claim 42, wherein the adequacy evaluation of step b includes comparing a first characteristic of the contour line at a first location on the contour line to second and third characteristics of respective second and third contour lines at respective locations on the second and third contour lines.

50. The arthroplasty jig of claim 42, wherein the adequacy evaluation of step b includes comparing an elevational change between a first location on the contour line to a second location on another contour line.

51. The arthroplasty jig of claim 42, further comprising a cutting guide surface positioned and oriented relative to the mating surface to result in a cut in the patient surface with a desired position and orientation.

52. The arthroplasty jig of claim 51, wherein the desired position and orientation allows an prosthetic implant to restore a patient'"'"'s joint to a natural alignment.

53. A femoral arthroplasty jig for assisting in the performance of a femoral arthroplasty procedure on a femoral arthroplasty target region, the jig comprising:

a first side;

a second side generally opposite the first side; and

a mating surface in the first side and configured to matingly receive and contact certain surfaces of the femoral arthroplasty target region, the certain surfaces being limited to a medial articular condyle surface, a lateral articular condyle surface, and a generally planar area of an anterior side of a femoral shaft,

wherein the first side is configured to be oriented towards the femoral arthroplasty target region surface when the mating surface matingly receives and contacts the certain surfaces.

54. The femoral arthroplasty jig of claim 53, further comprising a cutting guide surface positioned and oriented relative to the mating surface to result in a cut in the femoral arthroplasty target region with a desired position and orientation.

55. The femoral arthroplasty jig of claim 54, wherein the desired position and orientation allows an prosthetic femoral implant to restore a patient'"'"'s knee joint to a natural alignment.

56. The femoral arthroplasty jig of claim 53, wherein the certain surfaces associated with the medial articular condyle surface are generally limited to an anterior and distal regions of the medial articular condyle.

57. The femoral arthroplasty jig of claim 53, wherein the certain surfaces associated with the lateral articular condyle surface are generally limited to an anterior and distal regions of the lateral articular condyle.

58. The femoral arthroplasty jig of claim 53, wherein the certain surfaces associated with the generally planar area of the anterior side of the femoral shaft are generally limited to being generally distal of the articulars genu and generally proximal of the capsular line.

59. A tibial arthroplasty jig for assisting in the performance of an tibial arthroplasty procedure on a tibial arthroplasty target region, the jig comprising:

a first side;

a second side generally opposite the first side; and

a mating surface in the first side and configured to matingly receive and contact certain surfaces of the tibial arthroplasty target region, the certain surfaces being limited to a medial articular plateau surface, a lateral articular plateau surface, and a generally planar area of an anterior side of a tibial shaft, wherein the first side is configured to be oriented towards the tibial arthroplasty target region surface when the mating surface matingly receives and contacts the certain surfaces.

60. The tibial arthroplasty jig of claim 59, further comprising a cutting guide surface positioned and oriented relative to the mating surface to result in a cut in the tibial arthroplasty target region with a desired position and orientation.

61. The tibial arthroplasty jig of claim 60, wherein the desired position and orientation allows an prosthetic tibial implant to restore a patient'"'"'s knee joint to a natural alignment.

62. The tibial arthroplasty jig of claim 59, wherein the certain surfaces associated with the generally planar area of the anterior side of the tibial shaft are generally limited to being generally distal of the tibial plateau edge and generally proximal of the tibial tuberosity.

63. A tibial arthroplasty jig for assisting in the performance of a tibial arthroplasty procedure on a tibial arthroplasty target region, the jig comprising:

a first side;

a second side generally opposite the first side; and

a mating surface in the first side and configured to matingly receive and contact a generally planar area of an anterior side of a tibial shaft distal of the tibial plateau edge and generally proximal of the tibial tuberosity,

wherein the first side is configured to be oriented towards the tibial arthroplasty target region surface when the mating surface matingly receives and contacts the planar area.

64. The tibial arthroplasty jig of claim 63, wherein the generally planar area includes a portion that extends distally from generally the tibial plateau edge to a point generally even with the beginning of a distal half to distal third of the tibial tuberosity.

65. The tibial arthroplasty jig of claim 64, wherein the portion extends medial-lateral from a medial edge of a medial tibia condyle to a point generally even with a medial edge of the tibial tuberosity.

66. The tibial arthroplasty jig of claim 65, wherein the portion generally tapers in a distal direction.

67. The tibial arthroplasty jig of claim 63, wherein the generally planar area includes a portion that extends distally from generally the tibial plateau edge to a point near a proximal boundary of the tibial tuberosity.

68. The tibial arthroplasty jig of claim 67, wherein the portion extends medial-lateral generally between a lateral edge and a medial edge of the tibial tuberosity.

69. The tibial arthroplasty jig of claim 68, wherein the portion is generally rectangular, having a long length extending medial-lateral.

70. The tibial arthroplasty jig of claim 63, wherein the generally planar area includes a portion that extends distally from generally the tibial plateau edge to a point generally even with the beginning of a distal two-thirds to distal three-quarters of the tibial tuberosity.

71. The tibial arthroplasty jig of claim 70, where the portion extends medial-lateral from generally a lateral edge of the tibial tuberosity to generally a lateral edge of a lateral tibia condyle.

72. The tibial arthroplasty jig of claim 71, wherein the portion generally tapers in a distal direction.

73. A femoral arthroplasty jig for assisting in the performance of a femoral arthroplasty procedure on a femoral arthroplasty target region, the jig comprising:

a first side;

a second side generally opposite the first side; and

a mating surface in the first side and configured to matingly receive and contact a generally planar area of an anterior side of a femoral shaft generally proximal of the patellar facet boarder and generally distal an articularis genu,

wherein the first side is configured to be oriented towards the femoral arthroplasty target region surface when the mating surface matingly receives and contacts the planar area.