Facet joint fixation system

• US 20050149030A1
• Filed: 12/19/2003
• Published: 07/07/2005
• Est. Priority Date: 12/19/2003
• Status: Abandoned Application

• Current Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Spine Incorporated (Johnson & Johnson)
• Inventors: DiNello, Alexandre Michel, Serhan, Hassan, Slivka, Michael Andrew
• Application Number:
  US10/742,193
• Publication Number:
  US 20050149030A1
• Time in Patent Office: Days
• US Class Current: 606/247
• CPC Class Codes: A61B 17/7064 Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive

Abstract

A facet joint fixation system that provides initial rigidity for stabilizing the facet joint, is sufficiently strong to withstand facet joint shear stresses, and (after supporting a successful fusion) can be resorbed by the body.

Claims

1. A bone fixation system:

a) a proximal head,

b) a distal tip, and

c) an elongated intermediate shaft portion having an outer surface comprising;

i) a proximal portion having fastening surface, and

ii) a smooth central portion,

wherein the shaft portion comprises a resorbable material.

2. The system of claim 1 wherein the fastening surface comprises a thread.

3. The system of claim 1 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

4. The system of claim 1 wherein the outer surface of the shaft further comprises:

iii) a smooth distal portion.

5. The system of claim 1 wherein the proximal head is distally tapered.

6. The system of claim 1 wherein the system is unitary.

7. The system of claim 1 wherein the shaft is cannulated, defining a longitudinal bore therein.

8. The system of claim 7 wherein the distal end of the shaft forms first and second deformable legs.

9. The system of claim 8 further comprising:

an insertion pin disposed within the bore.

10. The system of claim 9 further comprising an absorbable cable having a distal end connected to the proximal end of the insertion piece.

11. A spinal facet fixation system:

a) a proximal head,

b) a distal tip, and

c) a substantially cylindrical intermediate shaft portion having an outer surface comprising;

i) a proximal portion having fastening surface, and

ii) a smooth central portion, wherein the cylindrical portion comprises a resorbable material.

12. The system of claim 11 wherein the fastening surface comprises a thread.

13. The system of claim 11 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

14. The system of claim 11 wherein the outer surface of the shaft further comprises:

iii) a smooth distal portion.

15. The system of claim 11 wherein the proximal head is distally tapered.

16. The system of claim 11 wherein the system is unitary.

17. The system of claim 11 wherein the shaft is cannulated, defining a longitudinal bore therein.

18. The system of claim 17 wherein the distal end of the shaft forms first and second deformable legs.

19. The system of claim 18 further comprising:

an insertion pin disposed within the bore.

20. The system of claim 19 further comprising an absorbable cable having a distal end connected to the proximal end of the insertion piece.

21. A unitary spinal facet fixation system:

a) a proximal head,

b) a distal tip, and

c) a substantially cylindrical intermediate shaft portion having an outer surface comprising;

i) a proximal portion having fastening surface, and

ii) a smooth central portion.

22. The system of claim 21 wherein the fastening surface comprises a thread.

23. The system of claim 21 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

24. The system of claim 21 wherein the outer surface of the shaft further comprises:

iii) a smooth distal portion.

25. The system of claim 21 wherein the proximal head is distally tapered.

26. The system of claim 21 wherein the shaft portion comprises a resorbable material.

27. The system of claim 21 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

28. The system of claim 21 wherein the shaft portion comprises a resorbable material adapted to retain at least 50% of its tensile strength 6 months after implantation.

29. The system of claim 21, wherein the bioresorbable material loses at least 50% of its tensile strength within 12 months of implantation.

30. The system of claim 21 wherein the bioresorbable material comprises PLA.

31. A spinal facet fixation system comprising:

a) a proximal head,

b) a distal tip, and

c) a substantially cylindrical intermediate tubular shaft portion defining a longitudinal bore,

wherein the cylindrical portion comprises a resorbable material.

32. The system of claim 31 wherein the shaft portion comprises an outer surface having a fastening surface.

33. The system of claim 32 wherein the fastening surface is located only in a proximal portion of the shaft portion.

34. The system of claim 33 wherein the fastening surface comprises a thread.

35. The system of claim 32 wherein the fastening surface is located only in a proximal half of the proximal portion of the shaft.

36. The system of claim 32 wherein the outer surface of the shaft further comprises:

iii) a smooth distal portion.

37. The system of claim 32 wherein the proximal head is distally tapered.

38. The system of claim 31 wherein the system is unitary.

39. The system of claim 31 wherein a distal end of the shaft forms first and second deformable legs.

40. The system of claim 39 further comprising:

an insertion pin disposed within the bore.

41. A method of fixing a facet joint, comprising the steps of:

a) providing a bone fixation system;

a proximal head,

a distal tip, and

an elongated intermediate shaft portion having an outer surface comprising;

i) proximal portion having a fastening surface, and

ii) a smooth central portion,

wherein the shaft portion comprises a resorbable material, and

b) inserting the proximal head of the system through the facet joint.

42. The system of claim 41 wherein the fastening surface comprises a thread.

43. The system of claim 41 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

44. The system of claim 41 wherein the outer surface of the shaft further comprises:

iii) a smooth distal portion.

45. The system of claim 41 wherein the proximal head is distally tapered.

46. The system of claim 41 wherein the system is unitary.

47. The system of claim 41 wherein the shaft is cannulated, defining a longitudinal bore therein.

48. The system of claim 47 wherein the distal end of the shaft forms first and second deformable legs.

49. The system of claim 48 further comprising:

an insertion pin disposed within the bore.

50. The system of claim 49 further comprising an absorbable cable having a distal end connected to the proximal end of the insertion piece.

51. A bone fixation system:

a) a proximal head,

b) a distal tip, and

c) a substantially cylindrical intermediate shaft portion having an outer surface comprising;

i) a proximal portion having a fastening surface, and

ii) a smooth central portion, and

iii) a smooth distal portion.

52. The system of claim 51 wherein the fastening surface comprises a thread.

53. The system of claim 51 wherein the fastening surface is located only in the proximal half of proximal portion of the shaft.

54. The system of claim 53 wherein the fastening surface comprises a thread.

55. The system of claim 51 wherein the proximal head is distally tapered.

56. The system of claim 51 wherein the system is unitary.

57. The system of claim 51 wherein the shaft is cannulated, defining a longitudinal bore therein.

58. The system of claim 57 wherein the distal end of the shaft forms first and second deformable legs.

59. The system of claim 58 further comprising:

an insertion pin disposed within the bore.

60. The system of claim 59 further comprising:

an absorbable cable having a distal end connected to the proximal end of the insertion piece.

61. A facet joint fixation system comprising a pin comprising:

a) a proximal head,

b) a distal tip,

c) an elongated intermediate shaft portion having an outer surface, the shaft portion comprising;

i) a smooth portion,

ii) a smooth central portion, and

iii) a distal portion having a fastening surface.