Spinal system and method including lateral approach

• US 20060217806A1
• Filed: 03/28/2005
• Published: 09/28/2006
• Est. Priority Date: 03/28/2005
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Peterman, Marc M., Bono, Frank
• Granted Patent: US 7,749,269 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/3008 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30187 D-shaped or half-disc-shaped
• CPC Class Codes: A61F 2002/30383 made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
• CPC Class Codes: A61F 2002/30601 telescopic
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30772 Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/4627 with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4629 connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0034 : D-shaped
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• 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 2310/00293 : containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00329 : Glasses, e.g. bioglass
• CPC Class Codes: A61F 2310/00359 : Bone or bony tissue

Abstract

Embodiments of the invention include devices and methods for implanting a vertebral body spacer. A lateral surgical approach is contemplated with some disclosed procedures. Instruments of some embodiments are insertable into a disc space to achieve distraction, to determine a desired disc space height, and to select a corresponding implant.

Claims

1. A system for placing an implant between an endplate of an upper vertebra and an endplate of a lower vertebra comprising:

a trial instrument set with at least two trial instruments of different sizes, each trial instrument comprising;

an upper surface orientable toward the upper vertebra,

a lower surface orientable toward the lower vertebra, and

a leading end portion with segments that diverge from the leading end to meet the upper surface and the lower surface respectively; and

an implant with an elongated body positionable in a spinal disc space comprising;

an upper surface orientable toward the upper vertebra,

a lower surface orientable toward the lower vertebra,

a leading end portion and an opposite trailing end portion,

an at least partially convexly curved anterior sidewall extending between the leading end portion and the trailing end portion, and

a posterior sidewall extending between the leading end portion and the trailing end portion; and

wherein at least one of the upper surface and the lower surface are curved such that a height of the implant near its center is greater than a height of the implant at its leading end; and

wherein the height of the implant near its center is between about 7 mm and 19 mm; and

wherein the height of the implant at its leading end is at least about 3 mm less than the height of the implant near its center.

2. The system of claim 1 wherein the upper surface of at least one of the trial instruments is convexly curved.

3. The system of claim 1 wherein the lower surface of at least one of the trial instruments is convexly curved.

4. The system of claim 1 wherein the leading end portion of at least one of the trial instruments is a curve extending between the upper surface and the lower surface.

5. The system of claim 4 wherein the leading end portion of the trial instrument is a radius.

6. The system of claim 1 wherein at least one of the trial instruments is substantially the same shape as the implant.

7. The system of claim 1 wherein the upper surface of the implant is convexly curved.

8. The system of claim 1 wherein the lower surface of the implant is convexly curved.

9. The system of claim 1 wherein the anterior sidewall is defined by a maximally anterior portion, a first curved portion extending between the leading end portion and the maximally anterior portion, and a second curved portion extending between the trailing end portion and the maximally anterior portion.

10. The system of claim 1 further comprising an access portal insertable through an incision, and through which the trial instrument or the implant are passed.

11. The system of claim 10 wherein the access portal comprises a tubular port.

12. The system of claim 10 wherein the access portal comprises a retractor.

13. The system of claim 12 wherein the retractor comprises:

a first retractor portion having a proximal end and a distal end and being positionable in the incision;

a second retractor portion having a proximal end and a distal end and being positionable in the incision in cooperation with the first retractor portion; and

a separation instrument coupled between the proximal ends of the first and second retractor portions, the separation instrument being operable to displace the first and second retractor portions from an insertion configuration wherein the first and second retractor portions are adjacent one another to a second configuration wherein the first and second portions are separated from one another.

14. The system of claim 13 wherein the separation instrument is offset to one side of the axis.

15. The system of claim 13 further comprising an intermediate retractor removably mountable to the separation instrument, the intermediate retractor including a linking arm extending from the separation instrument toward the first and second retractor portions to a retractor blade, the retractor blade being transversely oriented to the linking arm and being positionable in the incision between the first and second retractor portions when the linking arm is mounted to the separation instrument and the first and second retractor portions are in the second configuration.

16. The system of claim 10 further comprising a dilator configured to increase the size of the incision prior to positioning of the access portal in the incision.

17. The system of claim 16 further comprising a set of dilators that includes:

an initial insertion dilator with a relatively smaller cross-section compared with other dilators in the set; and

a concentric dilator that fits over the initial insertion dilator to further open the incision.

18. A method of surgically placing an implant between vertebral bodies from a generally lateral surgical approach comprising the acts of:

positioning a patient such that an operative side of the patient is accessible;

making an incision in the operative side of the patient between the ribcage and the iliac crest of the patient;

locating an initial insertion dilator between the vertebral bodies;

dilating tissue with a first concentric dilator that fits over the initial insertion dilator to further open the incision;

removing vertebral disc material to create an opening for the implant between the vertebral bodies;

inserting a trial instrument between the vertebral bodies; and

inserting between the vertebral bodies an implant comprising;

an upper surface orientable toward the upper vertebra,

a lower surface orientable toward the lower vertebra,

a leading end portion and an opposite trailing end portion,

an anterior sidewall extending between the leading end portion and the trailing end portion, and

a posterior sidewall extending between the leading end portion and the trailing end portion; and

wherein at least one of the upper surface and the lower surface are curved such that a height of the implant near its center is greater than a height of the implant at its leading end; and

wherein the height of the implant near its center is between about 7 mm and 19 mm; and

wherein the height of the implant at its leading end is at least about 3 mm less than the height of the implant near its center.

19. The method of claim 18 wherein the act of positioning includes placing a protrusion against a non-operative side of the patient to cause separation between the patient'"'"'s ribcage and iliac crest on the operative side.

20. The method of claim 18 wherein the act of locating an initial insertion dilator includes locating a guidewire between the vertebral bodies.

21. The method of claim 18 wherein the act of locating an initial insertion dilator includes using image guidance to visualize the initial insertion dilator.

22. The method of claim 18 further comprising the act of dilating tissue with a second concentric dilator that fits over the first insertion dilator to further open the incision.

23. The method of claim 18 further comprising the act of inserting a retractor into the incision.

24. The method of claim 23 further comprising the act of coupling the retractor to at least one of the upper vertebral body and the lower vertebral body.

25. The method of claim 24 further comprising the act of coupling the retractor to at lest one of the upper vertebral body and the lower vertebral body with a fastener.

26. The method of claim 23 further comprising the act of operating the retractor to further open the incision.

27. The method of claim 18 wherein the act of removing vertebral disc material includes removing material with at least one of a pituitary rongeur, a rotary shaver, a rasp, and a scraper.

28. The method of claim 18 wherein the act of inserting a trial instrument distracts the vertebral bodies.

29. The method of claim 18 further comprising assessing fit of the trial instrument between the vertebral bodies after inserting the trial instrument.

30. A method of surgically placing an implant between vertebral bodies from a generally lateral surgical approach comprising the acts of:

positioning a patient such that an operative side of the patient is accessible;

making an incision in the operative side of the patient between the ribcage and the iliac crest of the patient;

locating an initial insertion dilator between the vertebral bodies;

dilating tissue with a first concentric dilator that fits over the initial insertion dilator to further open the incision;

removing vertebral disc material to create an opening for the implant between the vertebral bodies;

inserting a trial instrument between the vertebral bodies; and

inserting between the vertebral bodies an implant comprising;

a convexly curved upper surface orientable toward an endplate of an upper vertebra,

a convexly curved lower surface orientable toward an endplate of a lower vertebra,

a leading end portion and an opposite trailing end portion,

an anterior sidewall extending between the leading end portion and the trailing end portion, and

a posterior sidewall extending between the leading end portion and the trailing end portion; and

wherein the body includes a height between the upper and lower surfaces corresponding to a desired disc space height between the upper vertebra endplate and the lower vertebra endplate; and

wherein the leading end portion is structured for insertion into the disc space in an at least partially collapsed condition and the height is sized to restore the collapsed disc space to the desired disc space height as the body is inserted in the collapsed disc space.

31. The method of claim 30 wherein the act of positioning includes placing a protrusion against a non-operative side of the patient to cause separation between the patient'"'"'s ribcage and iliac crest on the operative side.

32. The method of claim 30 wherein the act of locating an initial insertion dilator includes locating a guidewire between the vertebral bodies.

33. The method of claim 30 wherein the act of locating an initial insertion dilator includes using image guidance to visualize the initial insertion dilator.

34. The method of claim 30 further comprising the act of dilating tissue with a second concentric dilator that fits over the first insertion dilator to further open the incision.

35. The method of claim 30 further comprising the act of inserting a retractor into the incision.

36. The method of claim 35 further comprising the act of coupling the retractor to at least one of the upper vertebral body and the lower vertebral body.

37. The method of claim 36 further comprising the act of coupling the retractor to at lest one of the upper vertebral body and the lower vertebral body with a fastener.

38. The method of claim 35 further comprising the act of operating the retractor to further open the incision.

39. The method of claim 30 wherein the act of removing vertebral disc material includes removing material with at least one of a pituitary rongeur, a rotary shaver, a rasp, and a scraper.

40. The method of claim 30 wherein the act of inserting a trial instrument distracts the vertebral bodies.

41. The method of claim 30 further comprising assessing fit of the trial instrument between the vertebral bodies after inserting the trial instrument.

46. The method of claim 30 wherein the act of inserting a trial instrument distracts the vertebral bodies.

47. The method of claim 30 further comprising assessing fit of the trial instrument between the vertebral bodies after inserting the trial instrument.

42. A method of surgically placing an implant between vertebral bodies from a generally lateral surgical approach comprising the acts of:

making an incision in an operative side of a patient between the ribcage and the iliac crest of the patient;

inserting a trial instrument between the vertebral bodies; and

inserting between the vertebral bodies an implant with an elongated body comprising;

an upper surface orientable toward an endplate of an upper vertebra,

a lower surface orientable toward an endplate of a lower vertebra,

a leading end portion and an opposite trailing end portion,

an anterior sidewall defined by a maximally anterior portion, a first curved portion extending between the leading end portion and the maximally anterior portion, and a second curved portion extending between the trailing end portion and the maximally anterior portion, and

a posterior sidewall extending between the leading end portion and the trailing end portion; and

wherein the act of inserting the implant includes placing the implant anteriorly between the vertebral bodies such that the first curved portion and the second curved portion of the anterior sidewall are substantially located between a cortical rim of the upper vertebra and a cortical rim of the lower vertebra.

43. The method of claim 42 wherein the act of locating an initial insertion dilator includes locating a guidewire between the vertebral bodies.

44. The method of claim 42 further comprising the act of inserting a retractor into the incision.

45. The method of claim 44 further comprising the act of operating the retractor to further open the incision.