Diskectomy instrument and method

• US 6,726,690 B2
• Filed: 01/16/2003
• Issued: 04/27/2004
• Est. Priority Date: 01/17/2002
• Status: Expired due to Term

• Current Assignee: Spinal Elements, Inc.
• Original Assignee: Concept Matrix, LLC
• Inventors: Eckman, Walter W.
• Primary Examiner(s): Robert, Eduardo C.
• Assistant Examiner(s): COMSTOCK, DAVID C
• Application Number:
  US10/345,525
• Publication Number:
  US 20030135218A1
• Time in Patent Office: 467 Days
• Field of Search: 606/79, 606/80, 606/81, 606/170, 606/167, 606/180
• US Class Current: 606/79
• CPC Class Codes: A61B 17/1659 Surgical rasps, files, planes, or scrapers
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/320016 Endoscopic cutting instruments, e.g. arthroscopes, resectoscopes A61B10/0233, A61B17/29, A61B17/3207 take precedence
• CPC Class Codes: A61B 17/320725 with radially expandable cutting or abrading elements A61B17/32075 takes precedence
• CPC Class Codes: A61B 2017/00261 Discectomy
• CPC Class Codes: A61B 2017/2929 with a head rotatable about the longitudinal axis of the shaft
• CPC Class Codes: A61B 2017/320028 with reciprocating movements

Abstract

A diskectomy instrument includes an elongate body, a blade and a drive stem. The elongate body has a distal end, a proximal end, and a blade opening proximate the distal end. The blade is removably and movably mounted within the elongate body proximate the blade opening. The blade has a distal end, a proximal end, a sharp edge, a ramped portion and a stem mating portion. The drive stem is movably mounted within the elongate body and has a distal end, a proximal end and a blade mating portion. The drive stem is configured to slidably engage the blade when the drive stem is moved distally thereby extending the at least one blade radially outward though the at least one blade opening. The blade mating portion is configured to cooperatively engage the stem mating portion of the blade when the drive stem is moved proximally thereby retracting the blade.

Claims

1. A diskectomy instrument, comprising:

a) an elongate body having a distal end and a proximal end, the elongate body having at least one blade opening proximate the distal end;

b) at least one blade removably and movably mounted at least partially within the elongate body proximate the at least one blade opening, the at least one blade having a distal end, a proximal end, at least one sharp edge extending at least partially between the distal end and the proximal end, a ramped portion and a stem mating portion; and

c) a drive stem movably mounted within the elongate body having a distal end, a proximal end and a blade mating portion, the drive stem being configured to slidably engage the at least one blade when the drive stem is moved distally thereby extending the at least one blade radially outward though the at least one blade opening and the blade mating portion being configured to cooperatively engage the stem mating portion of the blade when the drive stem is moved proximally thereby retracting the at least one blade.

2. The diskectomy instrument of claim 1, further comprising an actuator coupled to the proximal end of the drive stem to effectuate proximal and distal movement of the drive stem linearly within the elongate body.

3. The diskectomy instrument of claim 2, wherein the actuator is a positioning knob configured so that rotating the positioning knob in a first direction causes the drive stem to move distally and rotating the positioning knob in a second direction causes the drive stem to move proximally.

4. The diskectomy instrument of claim 3, wherein the positioning knob includes incremental indication marks which generally correspond to the radial position of the at least one blade relative to the elongate body.

5. The diskectomy instrument of claim 2, further comprising a positioning knob coupled to the actuator wherein rotating the positioning knob in a first direction causes the drive stem to move distally and rotating the positioning knob in a second direction causes the drive stem to move proximally.

6. The diskectomy instrument of claim 5, wherein the positioning knob includes incremental indication marks which generally correspond to the radial position of the at least one blade relative to the elongate body.

7. The diskectomy instrument of claim 2, further comprising a blade rotation knob coupled to the at least one blade wherein rotating the blade rotation knob causes the at least one blade to rotate in a cutting direction.

8. The diskectomy instrument of claim 7, wherein the actuator further comprises a ratchet mechanism coupled between the blade rotation knob and the at least one blade whereby partial turns of the blade rotation knob effectuate rotation of the at least one blade in the cutting direction.

9. The diskectomy instrument of claim 2, wherein the proximal end of the drive stem is externally threaded and the actuator is internally threaded, the actuator being rotatably mounted to the proximal end of the elongate body in such a manner that the external threads of the drive stem are in threaded engagement with the internal threads of the actuator and wherein rotation of the actuator in a first direction causes the drive stem to move distally and rotation of the actuator in a second direction causes the drive stem to move proximally by translation of the internal and external threads.

10. The diskectomy instrument of claim 2, wherein the proximal end of the drive stem is externally toothed and the actuator includes a drive gear, the actuator being rotatably mounted to the proximal end of the elongate body in such a manner that the teeth of the drive stem are in mesh engagement with the drive gear of the actuator and wherein rotation of the drive gear in a first direction causes the drive stem to move distally and rotation of the drive gear in a second direction causes the drive stem to move proximally.

11. The diskectomy instrument of claim 1, wherein the portions of the diskectomy instrument intended to contact internal human body matter are formed of a biologically compatible material selected from the group consisting of stainless steel, titanium, nickel plated metal, a biocompatible metal, a biocompatible alloy, a biocompatible ceramic and a biocompatible polymeric material.

12. The diskectomy instrument of claim 1, wherein the stem mating portion of the blade is an indentation.

13. The diskectomy instrument of claim 1, wherein the stem mating portion of the blade is a protuberance.

14. The diskectomy instrument of claim 1, wherein the at least one blade is disposable.

15. The diskectomy instrument of claim 1, wherein the at least one blade is removed from the distal end of the elongate body.

16. The diskectomy instrument of claim 1, wherein the distal end of the elongate body is substantially closed and generally bluntly rounded.

17. The diskectomy instrument of claim 1, wherein the width of the at least one blade opening is in close tolerance to the width of the at least one blade thereby permitting the at least one blade opening to provide lateral support to the at least one blade during use.

18. The diskectomy instrument of claim 1, wherein the at least one blade is generally convexly-shaped proximate the at least one sharp edge thereby allowing the at least one blade to naturally find the most concave portions of a vertebra.

19. The diskectomy instrument of claim 1, wherein the elongate body further comprises a fixed abutment configured to engage the ramp when the drive stem is moved distally thereby assisting in extending the at least one blade radially outward.

20. The diskectomy instrument of claim 1 in combination with a working tube, the working tube having an elongate housing, a distal end, a proximal end and an interior lumen traversing through the elongate housing, the working tube being configured to be inserted through an incision less than about 50 mm in span.

21. The diskectomy instrument of claim 1 in combination with a working tube, the working tube having an elongate housing, a distal end, a proximal end and an interior lumen traversing through the elongate housing, the working tube being configured to be inserted through an incision less than about 25 mm in span.

22. A diskectomy instrument, comprising:

a) an elongate body having a distal end and a proximal end, the elongate body having a plurality of blade openings proximate the distal end;

b) a plurality of blades removably and movably mounted at least partially within the elongate body, each blade disposed proximate to a respective one of the plurality of blade openings, the plurality of blades each having a distal end, a proximal end, at least one sharp edge extending at least partially between the distal end and the proximal end, a ramped portion and a stem mating portion; and

c) a drive stem movably mounted within the elongate body having a distal end, a proximal end and a blade mating portion, the drive stem being configured to slidably engage each of the plurality of blades when the drive stem is moved distally thereby extending the plurality of blades radially outward through the respective plurality of blade openings and the blade mating portion being configured to cooperatively engage the stem mating portion of each of the plurality of blades when the drive stem is moved proximally thereby retracting the plurality of blades.

23. The diskectomy instrument of claim 22, wherein there are exactly four blades.

24. A diskectomy blade having a distal end and a proximal end for use in a diskectomy instrument, the diskectomy instrument including a body and a drive stem having a blade mating portion, the blade comprising:

a) at least one sharp edge extending at least partially between the distal end and the proximal end,

b) a ramped portion configured to slidably engage with one of the stem of the diskectomy instrument and the body of the diskectomy instrument, and

c) a mating portion configured to couple with the blade mating portion of the diskectomy instrument.

25. The diskectomy blade of claim 24, wherein the blade is reusable.

26. The diskectomy blade of claim 24, wherein the blade is disposable.

27. The diskectomy blade of claim 24, wherein the at least one blade is generally convexly-shaped proximate the at least one sharp edge thereby allowing the at least one blade to naturally find the most concave portions of a vertebra.

28. A method of using a diskectomy instrument, the diskectomy instrument including an elongate body having a blade opening, a blade having a sharp edge, a ramped portion and a stem mating portion, and a drive stem having a blade mating portion, wherein the drive stem is configured to slidably engage the at least one blade when the drive stem is moved distally thereby extending the blade radially outward though the blade opening and the blade mating portion is configured to cooperatively engage the stem mating portion of the blade when the drive stem is moved proximally thereby retracting the blade, the method comprising the steps of:

a) moving the drive stem proximally causing the blade mating portion to engage the stem mating portion of the blade thereby retracting the blade at least partially into the elongate body;

b) inserting a distal end of the diskectomy instrument into a small gap between a first vertebra and a second vertebra of a spine;

c) moving the drive stem distally causing the blade mating portion to engage the blade which in turn moves the blade distally and radially outward;

d) rotating the blade in a cutting direction defined by the orientation of the sharp edge;

e) moving the drive stem proximally causing the blade mating portion to engage the stem mating portion of the blade thereby retracting the blade at least partially into the elongate body; and

f) withdrawing the distal end of the diskectomy instrument from the small gap.

29. The method of claim 28, wherein the diskectomy instrument further includes an actuator coupled to the proximal end of the drive stem to effectuate proximal and distal movement of the drive stem linearly within the elongate body and a positioning knob coupled to the actuator, and wherein step c) includes rotating the positioning knob in a first direction to move the drive stem distally and steps a) and e) include rotating the positioning knob in a second direction to move the drive stem proximally.

30. The method of claim 28, wherein the diskectomy instrument further includes a blade rotation knob coupled to the blade through the elongate housing, and wherein step d) includes rotating the blade rotation knob to rotate the blade in the cutting direction.

31. A method of using a diskectomy instrument and a working tube in outpatient surgery, the diskectomy instrument including an elongate body having a blade opening, a blade having a sharp edge and a partially convex shape, a ramped portion and a stem mating portion, and a drive stem having a blade mating portion, wherein the drive stem is configured to slidably engage the at least one blade when the drive stem is moved distally thereby extending the blade radially outward though the blade opening and the blade mating portion is configured to cooperatively engage the stem mating portion of the blade when the drive stem is moved proximally thereby retracting the blade, the method comprising the steps of:

a) moving the drive stem proximally causing the blade mating portion to engage the stem mating portion of the blade thereby retracting the blade at least partially into the elongate body;

b) inserting a distal end of the working tube proximate a small gap between a first vertebra and a second vertebra of a spine accessible through an incision between about 10mm and about 100 mm in span;

c) inserting a distal end of the diskectomy instrument into the working tube in order to access the intervertebral space between the first and second vertebrae and into the small gap between the first and second vertebrae;

d) moving the drive stem distally causing the drive stem to engage the blade which in turn moves the blade distally and radially outward;

e) rotating the blade in a cutting direction defined by the orientation of the sharp edge so that the convexly-shaped blade finds the most concave portions of the first and second vertebrae;

f) moving the drive stem proximally causing the blade mating portion to engage the stem mating portion of the blade thereby retracting the blade at least partially into the elongate body; and

g) withdrawing the distal end of the diskectomy instrument from the disk space and the working tube.