Method and apparatus for bone fracture fixation

• US 20050065521A1
• Filed: 11/03/2004
• Published: 03/24/2005
• Est. Priority Date: 02/22/2002
• Status: Abandoned Application

• Current Assignee: Biomet Microfixation LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Biomet Microfixation LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Schumacher, Brian S., Duncan, Jeffrey A., Steger, Shon D.
• Application Number:
  US10/980,705
• Publication Number:
  US 20050065521A1
• Time in Patent Office: Days
• US Class Current: 606/281
• CPC Class Codes: A61B 17/80 Cortical plates , i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
• CPC Class Codes: A61B 17/8047 wherein the additional element surrounds the screw head in the plate hole A61B17/8052 takes precedence
• CPC Class Codes: A61B 17/8052 immobilised relative to screws by interlocking form of the heads and plate holes, e.g. conical or threaded
• CPC Class Codes: A61B 17/8076 for the ribs or the sternum
• CPC Class Codes: A61B 17/8685 comprising multiple separate parts
• CPC Class Codes: A61B 17/8863 Apparatus for shaping or cutting osteosynthesis equipment by medical personnel
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable, resorptive for implantable prostheses A61F2210/0004

Abstract

A plate for coupling severed bone regions comprising at least one bridge region, the at least one bridge region terminating in at least two bone fixation regions. The at least two bone fixation regions each contain at least one aperture for receiving a suitable fastening device for securing the plate to the bone regions to be coupled. The bridge region may be configured so as to be easily severed by a suitable severing device such as surgical scissors. The plate and fastening device may be formed from a bio-compatible or bio-resorbable material.

Claims

1. A device for coupling bone across an osteotomy, comprising:

a plate having at least two bone fixation regions and at least one bridge region, said bridge region having an aspect ratio defining an optimum height and width of said bridge region to accommodate a load applied across the osteotomy and minimize a cut force required to sever said bridge region.

2. The device of claim 1, wherein said at least two bone fixation regions includes at least one aperture.

3. The device of claim 2, wherein the apertures are internally threaded.

4. The device of claim 1, further including a fastening device adapted to engage said bone fixation regions to secure said bone fixation regions to one or more portions of bone,

5. The device of claim 4, wherein said fastening device includes an externally threaded lower shaft portion for engaging the bone, an externally threaded upper shaft portion, and a head member that is internally threaded for engaging said upper shaft portion.

6. The device of claim 5, wherein said head member is externally threaded for engaging one of said internally threaded apertures.

7. The device of claim 5, wherein said fastener includes a flange portion between said lower shaft portion and said upper shaft portion.

8. The device of claim 4, wherein said fastening device is made from a bio-resorbable material.

9. The device of claim 4, wherein said fastening device is made from a bio-compatible material.

10. The device of claim 4, wherein said fastening device includes a pointed end portion.

11. The device of claim 4, wherein said fastening device is self-drilling

12. The device of claim 1, wherein said bridge region spans the osteotomy.

13. The device of claim 1, wherein said bridge region spans the bone.

14. The device of claim 1, wherein said bridge region is longitudinally disposed at an angle relative to at least one of said bone fixation regions.

15. The device of claim 1, wherein said bridge region is longitudinally disposed at an angle relative to two or more of said bone fixation regions.

16. The device of claim 1, wherein an additional bridge region extends from said bridge region, said additional bridge region terminating in an additional bone fixation region.

17. The device of claim 1, wherein an additional bridge region extends from said bone fixation region, said additional bridge region terminating in an additional bone fixation region.

18. The device of claim 1, wherein said at least two bone fixation regions includes an angled portion extending upwardly in a plane of said bridge region.

19. The device of claim 1, wherein said plate includes at least four bridge regions, each of said bridge region coupled to two or more bone fixation regions.

20. The device of claim 19, wherein said bone fixation regions extend angularly from said bridge region.

21. The device of claim 20, wherein said bone fixation regions have at least two apertures.

22. The device of claim 1, wherein said bone fixation region is coupled on one or more ends to one or more intersecting bridge regions.

23. The device of claim 1, wherein said bone fixation regions are coupled on one or more ends to one or more bridge regions, one of said bridge regions defining a common bridge region.

24. The device of claim 1, wherein said bridge region includes multiple bridge regions terminating in bone fixation regions and disposed in a parallel relationship to each other.

25. The device of claim 1, wherein said bone fixation regions include a portion disposed generally linearly with said upper surface and a stepped portion offset from said upper surface.

26. The device of claim 1, wherein said plate includes bio-resorbable material.

27. The device of claim 1, wherein said plate includes bio-compatible material.

28. The device of claim 27, wherein said biocompatible material is an implant grade metal.

29. The device of claim 28, wherein said implant grade metal is selected from among:

commercially pure titanium, titanium alloys, stainless steel and zirconium.

30. The device of claim 1, wherein said bridge region includes a height less than about 0.55 times a width of said bone fixation regions.

31. The device of claim 1, wherein said height of said bridge region is greater than about 1.1 times said width of said bone fixation region.

32. The device of claim 1, wherein a maximum distance between a lower surface and an upper surface of said bone fixation region is less than about 0.12 inches.

33. The device of claim 1, wherein said height of said bridge region is less than about 0.055 inches.

34. The device of claim 1, wherein said height and width of said bridge region are given by the following equation, wherein X is said cut force in pounds-force and ‘

a’

is the area;

35. The device of claim 34, wherein said cut force X is chosen from a group comprising:

63.7, 55.1, 22.2, and 19.2.

36. The device of claim 34, wherein a cross-section of said bridge region is generally rectangular.

37. The device of claim 1, wherein said height and width of said bridge region are given by the following equation, wherein X is said cut force in pounds-force and ‘

a’

is the area;

38. The device of claim 37, wherein said cut force X is chosen from a group comprising:

63.7, 55.1, 22.2, and 19.2.

39. The device of claim 37, wherein a cross-section of said bridge region is generally rectangular.

40. The device of claim 1, wherein a cross-section of said bridge region is generally rectangular.

41. The device of claim 1, wherein said cut force required to sever said bridge region is less than 452 pounds-force.

42. The device of claim 1, wherein said cut force required to sever said bridge region is less than 387 pounds-force.

43. The device of claim 1, wherein said cut force required to sever said bridge region is less than 335 pounds-force.

44. The device of claim 1, wherein said cut force required to sever said bridge region is less than 157 pounds-force.

45. The device of claim 1, wherein said cut force required to sever said bridge region is less than 136 pounds-force.

46. The device of claim 1, wherein said cut force required to sever said bridge region is less than 116 pounds-force.

47. A device for coupling bone across an osteotomy, comprising:

at least two bone fixation regions, said at least two bone fixation regions having an upper surface, a lower surface, and a perimeter surface; and

at least one bridge region having a height and a width, said bridge region generally disposed between said at least two bone fixation regions and offset from at least one of said upper surface, or said lower surface.

48. The device of claim 47, wherein said height and width of said bridge region are given by the following equation, wherein X is said cut force in pounds-force:

49. The device of claim 48, wherein said cut force X is chosen from a group comprising:

63.7, 55.1, 22.2, and 19.2.

50. The device of claim 48, wherein a cross-section of said bridge region is generally rectangular.

51. The device of claim 47, wherein said height and width of said bridge region are given by the following equation, wherein X is said cut force in pounds-force:

52. The device of claim 51, wherein said cut force X is chosen from a group comprising:

63.7, 55.1, 22.2, and 19.2.

53. The device of claim 51, wherein a cross-section of said bridge region is generally rectangular.

54. The device of claim 47, wherein a cross-section of said bridge region is generally rectangular.

55. The device of claim 47, further including a fastening device adapted to engage said bone fixation regions to secure said bone fixation regions to one or more portions of bone, said fastening device adapted to be disposed through apertures formed through said bone fixation regions to secure said bone fixation regions to one or more portions of bone.

56. The device of claim 55, wherein said fastening device is capable of engaging said apertures and securing said bone fixation regions to one or more portions of severed bone.

57. The device of claim 55, wherein said fastening device is includes an externally threaded lower shaft portion for engaging a bone, an externally threaded upper shaft portion, and a head member that is internally threaded for engaging said upper shaft portion.

58. The device of claim 57, wherein said head member is externally threaded for engaging one of said internally threaded apertures.

59. The fastening device of claim 57, wherein said fastener includes a flange portion between said lower shaft portion and said upper shaft portion.

60. The device of claim 55, wherein said fastening device is made from a bio-resorbable material.

61. The device of claim 55, wherein said fastening device is made from a bio-compatible material.

62. The device of claim 55, wherein said biocompatible material is an implant grade metal.

63. The device of claim 62, wherein said implant grade metal is selected from among:

commercially pure titanium, titanium alloys, stainless steel and zirconium.

64. The device of claim 55, wherein said fastening device includes a pointed end portion.

65. The device of claim 55, wherein said fastening device is self-drilling.

66. The device of claim 55, wherein said internal apertures are arranged in an asymmetric pattern.

67. The device of claim 55, wherein said apertures are internally threaded.

68. The device of claim 47, wherein one or more of said bridge regions span the osteotomy.

69. The device of claim 47, wherein one or more of said bridge regions span the bone.

70. The device of claim 47, wherein said bridge region is longitudinally disposed at an angle relative at least one of said bone fixation regions.

71. The device of claim 47, wherein said bridge region is longitudinally disposed at an angle relative both of said bone fixation regions.

72. The device of claim 47, wherein an additional bridge region extends from said bridge region, said additional bridge region terminating in a bone fixation region.

73. The device of claim 47, wherein said bone fixation region includes an angled portion extending upwardly in a plane of said bridge region.

74. The device of claim 73, wherein said bone fixation region includes said angled portion and a planar portion generally coplanar with said bridge region.

75. The device of claim 47, wherein the device is comprised of at least four bridge regions with each bridge region coupled to two or more bone fixation regions.

76. The device of claim 75, wherein said bone fixation regions extend angularly from said bridge region.

77. The device of claim 76, wherein said bone fixation regions have at least two apertures.

78. The device of claim 47, wherein said bone fixation regions are coupled on one or more ends to one or more intersecting bridge regions.

79. The device of claim 47, wherein said bone fixation regions are coupled on one or more ends to one or more bridge regions, one of the one or more bridge regions defining a common bridge region.

80. The device of claim 47, wherein said bridge region is multiple bridge regions terminating in bone fixation regions and disposed in a parallel relationship to each other and interconnected by a backbone.

81. The device of claim 47, wherein said bone fixation regions include a portion disposed generally linearly with said bridge region and a stepped portion offset from said linear portion.

82. The device of claim 47, wherein said bridge region and said bone fixation regions include bio-resorbable material.

83. The device of claim 47, wherein said bridge region and said bone fixation regions bio-compatible material.

84. The device of claim 47, wherein said cut force required to sever said bridge region is less than 452 pounds-force.

85. The device of claim 47, wherein said cut force required to sever said bridge region is less than 387 pounds-force.

86. The device of claim 47, wherein said cut force required to sever said bridge region is less than 335 pounds-force.

87. The device of claim 47, wherein said cut force required to sever said bridge region is less than 157 pounds-force.

88. The device of claim 47, wherein said cut force required to sever said bridge region is less than 136 pounds-force.

89. The device of claim 47, wherein said cut force required to sever said bridge region is less than 116 pounds-force.

90. A method comprising:

determining a load applied across separated bone regions;

determining a cross-sectional area of a bridge region of a plate secured to said separated bone regions, said cross-sectional area capable of withstanding said determined load;

determining an acceptable cut force for said bridge region; and

calculating an aspect ratio to determine an optimum height and width of said bridge region to accommodate said load applied across the bone regions and said cut force required to sever said bridge region.

91. The method of claim 90, further comprising providing a bone reapproximation device to laterally hook and reapproximate the separated bone regions prior to applying said plate.

92. The method of claim 90, further comprising fastening the bone coupling device to the reapproximated bone regions using a fastener.

93. The device of claim 90, wherein calculating said aspect ratio is performed by the following equation, wherein X is said cut force in foot-lb:

94. The device of claim 93, wherein calculating said aspect ratio includes choosing said cut force X from a group comprising:

63.7, 55.1, 22.2, and 19.2.

95. The device of claim 93, wherein calculating said aspect ratio is performed by the following equation, wherein X is said cut force in pounds-force:

96. The device of claim 95, wherein calculating said aspect ratio includes choosing said cut force X from a group comprising:

63.7, 55.1, 22.2, and 19.2.