System and methods for performing percutaneous pedicle integrity assessments

• US 7,664,544 B2
• Filed: 04/30/2004
• Issued: 02/16/2010
• Est. Priority Date: 10/30/2002
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Martinelli, Scot, Finley, Eric, Elbanna, Jamil, Miles, Patrick, Kaula, Norbert, Gharib, James, Farquhar, Allen
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): Foreman; Jonathan M
• Application Number:
  US10/836,105
• Publication Number:
  US 20050004623A1
• Time in Patent Office: 2,118 Days
• Field of Search: 600/300, 600/301, 600/546, 600/554, 606/61, 606/72
• US Class Current: 600/546
• CPC Class Codes: A61B 17/1626 Control means; Display units
• CPC Class Codes: A61B 17/1655 for tapping
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 2505/05 Surgical care
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/1104 induced by stimuli or drugs; A61B5/1102 takes precedence; investigating medicinal preparations G01N33/15
• CPC Class Codes: A61B 5/1106 to assess neuromuscular blockade, e.g. to estimate depth of anaesthesia
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin

Abstract

The present invention involves systems and related methods for performing percutaneous pedicle integrity assessments involving the use of neurophysiology.

Claims

1. A method for performing percutaneous pedicle integrity assessments, comprising the steps of:

(a) percutaneously introducing an insulation member to a pedicle target site;

(b) establishing electrical communication between a K-wire and an interior of a pedicle screw pilot hole by bringing said K-wire into contact with a tap member disposed through said insulation member, said tap member having a longitudinal lumen for receiving and passing said K-wire therethrough;

(c) applying a stimulation signal to said K-wire; and

(d) monitoring to assess whether nerves adjacent said pedicle are innervating as a result of the step of applying said stimulation signal to said K-wire.

2. The method of claim 1 and further, wherein the step (d) of monitoring to assess whether nerves adjacent said pedicle are innervating is performed by an EMG monitoring system that detects a voltage response from muscles innervated by said nerves.

3. The method of claim 2 and further, wherein said EMG monitoring system is in electrical communication with said stimulation element and directs said application of said stimulation signal.

4. The method of claim 3 and further, comprising the additional step of determining a relationship between said stimulation signal and said voltage response to indicate said pedicle integrity.

5. The method of claim 4 and further, wherein said relationship is the threshold stimulation current level required to evoke a predetermined voltage response value.

6. The method of claim 4 and further, wherein said EMG system is configured to communicate said relationship to a user.

7. A method for performing percutaneous pedicle integrity assessments, comprising the steps of:

(a) percutaneously introducing to a pedicle target site an insulation member comprising a tubular element dimensioned to receive a tap member and a K-wire, the tap member having a longitudinal lumen for receiving and passing said K-wire therethrough to establish electrical communication therebetween;

(b) establishing electrical communication between said K-wire and an interior of a pedicle screw pilot hole;

(c) applying a stimulation signal to said K-wire; and

(d) monitoring to assess whether nerves adjacent said pedicle are innervating as a result of the step of applying said stimulation signal to said stimulation element.

8. The method of claim 7 and further, wherein the step (d) of monitoring to assess whether nerves adjacent said pedicle are innervating is performed by an EMG monitoring system that detects a voltage response from muscles innervated by said nerves.

9. The method of claim 8 and further, wherein said EMG monitoring system is in electrical communication with said stimulation element and directs said application of said stimulation signal.

10. The method of claim 9 and further, comprising the additional step of determining a relationship between said stimulation signal and said voltage response to indicate said pedicle integrity.

11. The method of claim 10 and further, wherein said relationship is the threshold stimulation current level required to evoke a predetermined voltage response value.

12. The method of claim 10 and further, wherein said EMG system is configured to communicate said relationship to a user.

13. A method for performing percutaneous pedicle integrity assessments, comprising the steps of:

(a) percutaneously introducing an insulation member to a pedicle target site;

(b) establishing electrical communication between a stimulation element and an interior of a pedicle screw pilot hole by bringing said stimulation element into contact with a tap member disposed through said insulation member;

(c) directing the application of a stimulation signal to said stimulation element with an EMG system in electrical communication with said stimulation element;

(d) detecting a voltage response with said EMG system from muscles innervated by nerves adjacent said pedicle to assess whether said nerves are innervating as a result of the step of applying said stimulation signal to said stimulation element;

(e) determining a relationship between said stimulation signal and said voltage response to indicate said pedicle integrity; and

(f) displaying at least one of graphical and alpha-numeric indicia to communicate said relationship to said user.

14. The method of claim 13 and further, wherein bringing said stimulation element into contact with said tap member is accomplished by attaching said stimulation element to a proximal end of said tap member.

15. The method of claim 13 and further, wherein said stimulation element is an electric coupling device.

16. The method of claim 15 and further, wherein said electric coupling device engages a proximal end of said tap member.

17. The method of claim 16 and further wherein said electric coupling device is a clamp-style coupler.

18. The method of claim 15 and further, wherein said electric coupling device is situated at the proximal end of said insulation member and said tap member is disposed through said electric coupling device.

19. The method of claim 13 and further, wherein said relationship is the threshold stimulation current level required to evoke a predetermined voltage response value.

20. The method of claim 19 and further, wherein said EMG system determines said threshold stimulation current level by automatically adjusting the current of said stimulation signal until said EMG system detects said predetermined voltage response value.

21. The method of claim 20 and further, wherein said EMG system establishes a first bracket containing said threshold stimulation level and then bisects said first bracket to establish a smaller second bracket containing said threshold stimulation level.

22. A method for performing percutaneous pedicle integrity assessments, comprising the steps of:

(a) percutaneously introducing to a pedicle target site an insulation member comprising a tubular element dimensioned to receive a pedicle screw pilot hole preparation tool;

(b) establishing electrical communication between a stimulation element and an interior of a pedicle screw pilot hole;

(c) directing the application of a stimulation signal to said stimulation element with an EMG system in electrical communication with said stimulation element;

(d) detecting a voltage response with said EMG system from muscles innervated by nerves adjacent said pedicle to assess whether said nerves are innervating as a result of the step of applying said stimulation signal to said stimulation element;

(e) determining a relationship between said stimulation signal and said voltage response to indicate said pedicle integrity; and

(f) displaying at least one of graphical and alpha-numeric indicia to communicate said relationship to said user.

23. The method of claim 22 and further, wherein step (b) of establishing electrical communication between said stimulation element and said interior of said pedicle screw pilot hole is accomplished by:

(i) introducing said pedicle screw pilot hole preparation tool into said pedicle screw pilot hole; and

(ii) establishing electrical communication between said stimulation element and said pedicle screw pilot hole preparation tool.

24. The method of claim 22 and further, wherein electrical communication is established between said stimulation element and said pedicle screw pilot hole preparation tool by attaching said stimulation element to a proximal end of said pedicle screw pilot hole preparation tool.

25. The method of claim 24 and further, wherein said stimulation element is an electric coupling device.

26. The method of claim 25 and further, wherein said electric coupling device is a clamp-style coupler.

27. The method of claim 22 and further, wherein a pedicle screw pilot hole preparation tool is coupled to a proximal end of said insulation member.

28. The method of claim 27 and further, wherein said stimulation element is coupled to a proximal end of said pedicle screw pilot hole preparation tool.

29. The method of claim 28 and further, wherein said stimulation element is an electric coupler situated at the proximal end of said insulation member and said pedicle screw pilot hole preparation tool is disposed through said electrical coupler.

30. The method of claim 22 and further, wherein said pedicle screw pilot hole preparation tool is a tap member.

31. The method of claim 22 and further, wherein said relationship is the threshold stimulation current level required to evoke a predetermined voltage response value.

32. The method of claim 31 and further, wherein said EMG system determines said threshold stimulation current level by automatically adjusting the current of said stimulation signal until said EMG system detects said predetermined voltage response value.

33. The method of claim 32 and further, wherein said EMG system establishes a first bracket containing said threshold stimulation level and then bisects said first bracket to establish a smaller second bracket containing said threshold stimulation level.