Intervertebral disc replacement method

• US 7,104,986 B2
• Filed: 05/12/2003
• Issued: 09/12/2006
• Est. Priority Date: 07/16/1996
• Status: Expired due to Fees

• Current Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Original Assignee: ArthroCare Corporation (Smith & Nephew PLC)
• Inventors: Conforti, Zsuzsi, Woloszko, Jean, Hovda, David C., Martini, Brian
• Primary Examiner(s): Cohen, Les S.
• Application Number:
  US10/435,825
• Publication Number:
  US 20040024398A1
• Time in Patent Office: 1,219 Days
• Field of Search: 606/32, 606/34, 606/41, 606/49, 606/50, 607/99, 607/105, 607/113, 128/898, 604/35, 604/114, 623/17.16
• US Class Current: 606/32
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/1485 having a short rigid shaft for accessing the inner body through natural openings
• CPC Class Codes: A61B 18/149 bow shaped or with rotatable body at cantilever end, e.g. for resectoscopes, or coagulating rollers
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/00097 one of the thermometric elements being an electrode or the heating element
• CPC Class Codes: A61B 2017/00101 using an array of thermosensors
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2017/003 Steerable
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/00119 : with metal oxide nitride
• CPC Class Codes: A61B 2018/0016 : Energy applicators arranged in a two- or three dimensional array
• CPC Class Codes: A61B 2018/00178 : Electrical connectors
• CPC Class Codes: A61B 2018/00196 : reciprocating lengthwise
• CPC Class Codes: A61B 2018/00327 : Ear, nose or throat
• CPC Class Codes: A61B 2018/00392 : Transmyocardial revascularisation
• CPC Class Codes: A61B 2018/00434 : Neural system
• CPC Class Codes: A61B 2018/00505 : Urinary tract
• CPC Class Codes: A61B 2018/00577 : Ablation
• CPC Class Codes: A61B 2018/00583 : Coblation, i.e. ablation using a cold plasma
• CPC Class Codes: A61B 2018/00642 : with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/0066 : without feedback, i.e. open loop control
• CPC Class Codes: A61B 2018/00678 : upper
• CPC Class Codes: A61B 2018/00702 : Power or energy
• CPC Class Codes: A61B 2018/00726 : Duty cycle
• CPC Class Codes: A61B 2018/00761 : Duration
• CPC Class Codes: A61B 2018/00791 : Temperature
• CPC Class Codes: A61B 2018/00797 : measured by multiple temperature sensors
• CPC Class Codes: A61B 2018/00821 : measured by a thermocouple
• CPC Class Codes: A61B 2018/00827 : Current
• CPC Class Codes: A61B 2018/00875 : Resistance or impedance
• CPC Class Codes: A61B 2018/00886 : Duration
• CPC Class Codes: A61B 2018/1213 : creating an arc
• CPC Class Codes: A61B 2018/124 : switching the output to different electrodes, e.g. sequentially
• CPC Class Codes: A61B 2018/1253 : monopolar
• CPC Class Codes: A61B 2018/126 : bipolar
• CPC Class Codes: A61B 2018/1273 : including multiple generators in one device
• CPC Class Codes: A61B 2018/1467 : using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/1472 : for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2018/1497 : Electrodes covering only part of the probe circumference
• CPC Class Codes: A61B 2018/162 : located on the probe body
• CPC Class Codes: A61B 2018/165 : Multiple indifferent electrodes
• CPC Class Codes: A61B 2090/378 : using ultrasound
• CPC Class Codes: A61B 2218/002 : Irrigation
• CPC Class Codes: A61F 2/2493 : Transmyocardial revascularisation [TMR] devices
• CPC Class Codes: A61M 25/0133 : Tip steering devices
• CPC Class Codes: A61M 25/0147 : with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61M 25/0158 : with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials

Abstract

The present invention provides systems and methods for selectively applying electrical energy to a target location within a patient'"'"'s body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to contract collagen fibers within the tissue structures. In one aspect of the invention, a system and method is provided for removing a vertebral disc in preparation for implanting a prosthetic disc or removing a portion of the vertebral disc such as the nucleus pulposus in preparation for placing a prosthetic nucleus within the annulus of the disc. The present invention also teaches shrinking residual tissue in preparation for placing the implants.

Claims

1. A method for preparing a patient for a prosthetic disc nucleus implant, by ablating tissue of a nucleus pulposus of a vertebral disc, the method comprising:

positioning a distal end of a shaft of an electrosurgical probe in contact with the vertebral disc, the probe having a plurality of electrodes coupled to a high frequency power supply, the plurality of electrodes comprising at least one active electrode and at least one return electrode, the active electrode being disposed towards the distal end of the shaft;

applying a high frequency voltage between the at least one active electrode and the at least one return electrode within the nucleus pulposus to ablate and/or vaporize the nucleus pulposus tissue; and

ablating and/or vaporizing significantly all of the nucleus pulposus, while preserving an annulus of the disc.

2. The method of claim 1, further comprising delivering an electrically conductive medium to the vertebral disc.

3. The method of claim 2, wherein ablating or vaporizing nucleus pulposus comprises generating electric field intensities between the at least one active electrode and at least one return electrode such that the electric field intensities are sufficient to vaporize at least a portion of the conductive medium in contact with one of the active electrodes.

4. The method of claim 2, wherein delivering an electrically conductive medium comprises delivering an electrically conductive fluid into the disc.

5. The method of claim 2, wherein delivering an electrically conductive medium comprises delivering an electrically conductive gel onto the distal end of the shaft.

6. The method of claim 2 further comprising aspirating at least a portion of the conducting medium.

7. The method of claim 2, wherein ablating and/or vaporizing comprises removing nucleus pulposus tissue while preserving vertebral end-plates of the disc.

8. The method of claim 7, wherein preserving vertebral end plates comprises not ablating the endplates.

9. The method of claim 7, wherein preserving vertebral end plates comprises circulating conductive fluid to cool the endplates while ablating and/or vaporizing the disc.

10. The method of claim 1, further comprising shrinking a residue portion of the nucleus pulposus that remains after the act of ablating and/or vaporizing.

11. The method of claim 10, wherein the residue portion of the nucleus pulposus is attached to a vertebral end-plate.

12. The method of claim 10, wherein the shrinking act causes the portion of nucleus pulposus to be heated to a temperature in the range of from about 45°

C. to 90°

C.

13. The method of claim 12, wherein the shrinking act causes the portion of nucleus pulposus to be heated to a temperature in the range of from about 60°

C. to 70°

C.

14. The method of claim 1, wherein ablating and/or vaporizing the nucleus pulposus includes ablating and/or vaporizing a vertebral end-plate.

15. The method of claim 1, wherein electrosurgical probe comprises a tissue treatment portion which contains at least the active electrodes.

16. The method of claim 15, wherein the tissue treatment surface is curved and adapted to treat the disc.

17. The method of claim 15, where the tissue treatment surface has an axial length and a thickness substantially less than the axial length and a width substantially larger than said thickness to form a substantially planar body having an active side and a non-active side opposing the active side, wherein at least the active electrodes are on the active side.

18. The method of claim 1, wherein the at least one return electrode is located towards a distal end of the shaft.

19. The method of claim 1, wherein the at least one return electrode is located on the outer surface of the patient'"'"'s body.

20. The method of claim 1, wherein the at least one active electrode comprises a single, active electrode at the distal end of a shaft.

21. The method of claim 1, wherein the at least one active electrode comprises a plurality of electrically isolated active electrodes at the distal end of a shaft.

22. The method of claim 1, further comprising aspirating.

23. The method of claim 1, further comprising independently controlling current flow from the at least one active electrode based on impedance between the electrodes.

24. The method of claim 1, wherein the at least one return electrode is axially spaced on the shaft from the at least active electrode.

25. The method of claim 1, wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe through a percutaneous penetration in a patient.

26. The method of claim 25, wherein the percutaneous penetration is located on the patient'"'"'s back, abdomen, or thorax.

27. The method of claim 1, wherein the positioning step comprises introducing at least a distal portion of the electrosurgical probe anteriorly through the patient to the spine.

28. The method of claim 1, wherein the act of positioning comprises advancing the distal end of the shaft through an existing opening in the annulus fibrosus.

29. The method of claim 28, wherein the existing opening comprises a fissure in the annulus.

30. The method of claim 1, wherein the act of positioning comprises advancing the distal end of the shaft through a wall of the annulus fibrosus.

31. A method for treating a patient with a prosthetic disc nucleus implant, by ablating tissue of a nucleus pulposus of a vertebral disc, the method comprising:

positioning a distal end of a shaft of an electrosurgical probe in contact with the vertebral disc, the probe having a plurality of electrodes coupled to a high frequency power supply, the plurality of electrodes comprising at least one active electrode and at least one return electrode, the active electrode being disposed towards the distal end of the shaft;

applying a high frequency voltage between the at least one active electrode and the at least one return electrode within the nucleus pulposus to ablate and/or vaporize the nucleus pulposus tissue; and

ablating and/or vaporizing significantly all of the nucleus pulposus, while preserving an annulus of the disc; and

further comprising inserting the prosthetic disc nucleus implant into the patient subsequent to removal of the nucleus pulposus.

32. The method of claim 31, wherein the prosthetic disc nucleus implant is selected from a group consisting of metal, ceramic, polyurethane, hydrogel, protein hydrogel, or thermopolymer.