Precision depth guided instruments for use in vertebroplasty

• US 6,033,411 A
• Filed: 10/14/1997
• Issued: 03/07/2000
• Est. Priority Date: 10/14/1997
• Status: Expired due to Term

• Current Assignee: NeuroTherm, Inc. (Abbott Laboratories)
• Original Assignee: Parallax Medical, Inc. (Abbott Laboratories)
• Inventors: Preissman, Howard
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): NGO, LIEN M
• Application Number:
  US08/949,839
• Time in Patent Office: 875 Days
• Field of Search: 606/61, 606/73, 606/72, 606/60, 606/86, 606/79, 606/92, 606/93, 606/94, 606/95, 606/102, 606/169-180, 606/99, 604/164, 604/165, 604/166, 604/167
• US Class Current: 606/99
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 17/3472 for bones, e.g. intraosseus injections
• CPC Class Codes: A61B 17/3494 with safety means for protection against accidental cutting or pricking, e.g. limiting insertion depth, pressure sensors for the peridural space A61B17/3401
• CPC Class Codes: A61B 17/3496 Protecting sleeves or inner probes; Retractable tips for protecting body piercing guide needles A61M25/0612
• CPC Class Codes: A61B 17/8819 characterised by the introducer proximal part, e.g. cannula handle, or by parts which are inserted inside each other, e.g. stylet and cannula A61B17/8825 takes precedence
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61B 2090/062 penetration depth

Abstract

Precision depth guided instruments are provided for use in performing percutaneous implantation of hard tissue implant materials. A depth guided stylet include a point adapted for piercing hard tissue, and preferably, self-tapping threads for self-tapping into hard tissue. The stylet may include an elongated rod having a first section having a first diameter, and a second section having a second diameter larger than the first diameter. A cannula for use with a depth guided stylet includes an elongated tube having first and second open ends adapted for a depth guided stylet to pass therethrough. The cannula may include a pawl passing through the elongated tube for ratcheting against a rack of gear teeth provided on the stylet. Alternatively, a camming mechanism may be pivotal arranged on the stylet. Upon pivoting the camming mechanism, the cam surface provides a driving force against the cannula to drive the cannula along the stylet. A method of using the instruments is also disclosed, as is a kit which includes the instruments and which is used to open a pathway into hard tissue.

Claims

1. A stylet, comprising:

an elongated rod having first and second ends and a longitudinal axis, said first end terminating in a point adapted for piercing hard tissue; and

a camming mechanism pivotally mounted to provide a driving force to a cannula upon pivoting said camming mechanism with respect to said elongated rod.

2. The stylet of claim 1, further comprising a handle attached to said second end of said elongated rod.

3. The stylet of claim 1, further comprising:

self-tapping threads extending from said point along said elongated rod for a predetermined distance, said self-tapping threads adapted to self-tap into hard tissue.

4. A kit adapted to open a pathway into hard tissue, comprising:

a depth guided stylet comprising;

an elongated rod having first and second ends and a longitudinal axis, said first end terminating in a point adapted for piercing hard tissue; and

a camming mechanism pivotally mounted to provide a driving force to a cannula upon pivoting said camming mechanism with respect to said elongated rod; and

a cannula comprising;

an elongated tube having first and second ends, said first and second ends being open and adapted for said depth guided stylet to pass therethrough; and

a surface adapted to interact with said camming mechanism for the transfer of said driving force.

5. The kit of claim 4, further comprising:

self-tapping threads extending from said point along said elongated rod for a predetermined distance, said self-tapping threads adapted to self-tap into hard tissue.

6. The kit of claim 4, wherein said depth guided stylet further comprises a handle provided on said second end for providing a mechanical advantage to a user in rotating said elongated rod about said longitudinal axis.

7. The kit of claim 4, wherein said cannula further comprises a handle provided on said second end of said elongated tube, said surface being located on said handle of said cannula.

8. The kit of claim 7, further comprising a connector on said handle for connecting said cannula to tubing following removal of said stylet from within said cannula.

9. The kit of claim 8, wherein said connector comprise a Luer lock fitting.

10. The kit of claim 8, further comprising a bore through at least a portion of said handle, said bore connecting said connector with said elongated tube.

11. The kit of claim 10, wherein a longitudinal axis of said bore is non-parallel with and intersects a longitudinal axis of said elongated tube.

12. The kit of claim 4, wherein said elongated tube comprises a first section having a first diameter, and a second section having a second diameter larger than said first diameter;

and

wherein said first section is closer than said second section to said first end of said elongated tube.

13. The kit of claim 12, wherein said elongated rod comprises a first rod section having a first rod diameter, and a second rod section having a second rod diameter larger than said first rod diameter.

14. A stylet, comprising:

an elongated rod having first and second ends and a longitudinal axis, said first end terminating in a point adapted for piercing hard tissue;

threads extending from said point along said elongated rod for a predetermined distance; and

means for biasing said elongated rod with respect to a cannula, in a direction of said longitudinal axis, said means for biasing being movable from a first position, at which said elongated rod extends from an end of the cannula to allow said threads to engage tissue; and

a second position, at which said cannula covers substantially all of said threads.

15. A kit adapted to open a pathway into hard tissue, comprising:

a depth guided stylet comprising;

an elongated rod having first and second ends and a longitudinal axis, said first end terminating in a point adapted for piercing hard tissue; and

threads extending from said point along said elongated rod for a predetermined distance;

a cannula comprising;

an elongated tube having first and second ends, said first and second ends being open and adapted for said elongated rod to pass therethrough; and

means for biasing said cannula, in a direction of said longitudinal axis, with respect to said stylet, said means for biasing being movable from a first position, at which said elongated rod extends from an end of the cannula to allow said threads to engage tissue; and

a second position, at which said cannula covers substantially all of said threads.