Expandable reamer
An expandable reamer for forming a space within a vertebral disc includes a pair of opposing blades which have a expanded state and a retracted state. The blades being pivotally positioned at the distal end of a shaft assembly. A shaft housing being substantially disposed about the shaft assembly. The proximal end of the shaft assembly being operatively engaged by a control device which when rotated allows the blades to be fully retracted for insertion into a pre-bored hole and then to be expanded incrementally until the cavity is bored as desired.
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The present Utility Patent Application claims priority to Provisional Application No. 60/182,610 filed Feb. 15, 2000, the entire contents of which being incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCHNot Applicable
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to an expandable reamer for use in surgery, particularly in orthopedic applications.
2. Description of the Related Art
U.S. Pat. No. 5,445,639 to Kuslich et al., describes an intervertebral reamer which is used to ream out the interior of a degenerated disc to clean the interbody space. U.S. Pat. Nos. 5,549,679 and 5,571,189 to Kuslich describes a device and method for stabilizing the spinal segment with an expandable, porous fabric implant for insertion into the interior of a reamed out disc which is packed with material to facilitate bony fusion.
U.S. Pat. No. 5,928,239 to Mirza discloses a reamer which has a shaft and a cutting tip attached through a free rotating hinge such that high speed rotation allows the tip to be deflected outwardly to form a cavity. U.S. Pat. No. 5,591,170 to Spievack et al discloses a powered bone saw which inserts its cutting blade through a bored intramedullary canal.
The reamer of U.S. Pat. No. 5,445,639 is better suited to make a cylindrical bore than a spherical bore as is needed for the methods and apparatus of U.S. Pat. Nos. 5,549,679 and 5,571,189, the disclosure of all of which are incorporated herein by reference. There exists, therefore, a need for an instrument which will simplify the surgeon's task of forming a chamber within the interbody space.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. § 1.56(a) exists.
SUMMARY OF THE INVENTIONThe invention provides a surgical tool is for forming hollow chambers within bone that are larger in diameter than the external opening into the chamber. The tool has a distal end with external dimensions sized to be passed through the patient's anatomy to a point of entry into the bone. Retractable cutting blades are provided on the cutting end. The blades can be extended to cut a cavity greater than the diameter of the surgical tool.
A detailed description of the invention is hereafter described with specific reference being made to the drawings in which:
Reference is now directed to
In
As may best be seen in
The diameter of shaft 136 at distal end 172 is sized such that shaft 136 can be inserted into a patient's body with distal end 172 placed against a diseased disc or other bone without shaft 136 having undue interference with other anatomical organs.
In the embodiment shown, the guide member 182 is inserted into opening 204 with the elongated blade shaft 140 and the blade advancing tab 148 as well as blade guides 156 fully inserted into slot 184. The blade advancing tab 148 projects above the guide member 182 such that a groove 210 may be provided in the blade advancer barrel 138 to allow the assembly to pass therewithin.
The guide member 182 may include a pin 212 which passes from the guide member 182 across the barrel opening 216 to engage the pin opening 232 of the slide door 214. When properly assembled the tab 148 protrudes through the tab opening 230 of the door 214 such as may be seen in
After the guide member 182 is inserted fully into the barrel 138, the slide door 214 is placed onto blade advancer barrel 138 to close the access opening 216. The slide door may be held at the proximal end by engagement of its tabs 220 to slots 222 in the barrel. The distal end of the door 214 is held in position by a lock ring 224 that engages with threads 226 or the like on the distal end of barrel 138 as is shown in
As stated above, the slide door 214 includes a pair of openings 230, 232. Opening 230 engages with tab 148 to keep the elongated shaft 140 from moving. Observation of the position of the pin 212 within the confines of opening 232 allows a user to track the degree of movement that the shaft 136 makes longitudinally in response to turning knob 194.
As may best be seen in
As may best be seen in
Turning to
Note that if the blades 114 and 116 were ever stuck in an open position, the handle 96 could be removed, allowing the tube to be removed and then the blades 114 and 116 would have nothing to keep them open. This blade setup allows disassembly if the blades are stuck open in the bone. Prior reamer designs may be difficult to disengage in such an event. In this design, the entire device may be disassembled from the proximal end such that the parts are released allowing the blades 114 and 116 to pivot freely. In the embodiment shown in
As shown in
The holder 100 includes an enlarged barrel 102 into which the turn wheel 96 may partially descend and a lower hollow cylindrical guide 104. The distal end 110 of shaft 92 includes a narrow tang 111 which has an opening therethrough to allow blades 114, 116 to be hingedly attached via a hinge pin member 118.
As best shown in
Turn wheel 96 may include depth marking slot 107 which allows the user to see how far the blades have extended or retracted. In addition, the portion of the shaft 92 which may be seen through the slot 107 may have visible markings or surface features to better provide a visual basis for determining the extent of the blade retraction or extension based on the relative position of the shaft 92 within the slot 107. In the unlikely event that the reamer blades 114, 116 cannot be readily retracted within the cavity being formed, the turn wheel 96 may be removed, allowing the holder 100 to slide away from the shaft 92. In such a case, the blades 114, 116 would freely pivot on hinge pin 118 allowing the remainder of the reamer 90 to be readily removed.
As may be best understood from viewing
As may best be seen in
In one embodiment of the invention, when the turn wheel 96 is assembled in the manner described above, the spring 95 (shown in
In an alternative embodiment of the invention, the turn wheel includes a plurality of engagement pins 131. Each engagement pins 131 is engaged to receiving holes 133. In order to rotate the wheel 96 the wheel 96 is pulled in the manner described above, but additionally must be pulled a sufficient distance away from the barrel 102 to disengage the pins 131 from the holes 133. The wheel 96 may then be rotated to a point where the pins 131 may be reinserted into the holes 133 in an advancing clockwise or counterclockwise manner.
When the reamer 90 is assembled in the manner described above, clockwise rotation of the turn wheel 96 causes shaft 92 to be pulled up tube 104 such that ramp portion 120, such as may be seen in
As shown in
As may be seen in
In operation, the blades 114 and 116 are fully retracted and the device 90 is inserted into an opening drilled into the body material where a cavity is to be formed. Typically a hole is drilled into the vertebral body or other bone or area that needs to be reamed to a diameter larger than the outside drill hole. The hole is drilled in the bone, and then a guide tube may be abutted against the bone and adjusted to the proper length or depth where it is desired to ream the hole. The reamer 90 is then inserted through the optional guide tube with the blades 114 and 116 in the retracted position, such as is shown in
In use, turning or rotating the turn wheel 96 relative to the barrel 102 causes the shaft 92 to be moved longitudinally relative to the shaft housing 104. This action causes the blades 114 and 116 to pivot around the pivot member 118 thereby expanding out from or retracting into the tapered ramps 119, as seen in
Once a reamed cavity is made, the blades 114 and 116 are retracted by rotating the turn wheel 96 in a direction opposite that which was used to expand the blades, until the blades 114 and 116 are fully retracted. However, it should be noted that unlike in the embodiment shown in
The surgeon may visualize the degree the blades 114 and 116 extend by viewing the position of the shaft 92 relative to the barrel 102, through view port 107. The shaft 92 may have markings or surface features to make such position determinations easier. In the embodiment shown, the surgeon can see how far down the shaft 92 moves as the turning wheel 96 is rotated. The reamer 90 may be calibrated to show the distance the blades project from the tool.
While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
Claims
1. An expandable reamer comprising:
- a) an elongated hollow shaft having a proximal and a distal end, the distal end being closed and having a pair of opposing side openings adjacent the closed end;
- b) a pair of internal blade members within said hollow shaft;
- c) a mechanism for moving said blades from a retracted position within the shaft to a cutting, extended position through said side openings.
2. The expandable reamer of claim 1 wherein said distal closed end includes an inner, centrally located wedge constructed and arranged to direct the internal blade members out of said side openings when pressed distally.
3. The expandable reamer of claim 2 wherein said internal blade members each include an elongated shaft having a distal and a proximal end, said proximal end extending up to said blade moving mechanism and a cutting blade on a distal end of said elongated shaft which are completely within said hollow shaft until said elongated shafts are urged distally by said blade moving mechanism.
4. The expandable reamer of claim 3 wherein said blade moving mechanism is constructed and arranged to engage said proximal end of said blade member elongated shaft and simultaneously move both blades distally or proximally in response to operator movement of said blade moving mechanism.
5. The expandable reamer of claim 4 wherein said blade moving mechanism includes an adjusting screw which when rotated causes said blades to move distally or proximally in said elongated hollow tube in response to the direction of rotation and degree of rotation.
6. The expandable reamer of claim 5 further including an indicator mechanism toward the proximal end of said reamer which is visible from the outside of said reamer and shows relative movement of said blades proximally and distally within said hollow shaft to indicate position of the cutting blades.
7. The expandable reamer of claim 6 wherein said reamer includes a mechanism for applying rotational torque to said hollow shaft such that said cutting blades rotate and provide a cutting operation.
8. The expandable reamer of claim 7 wherein said cutting blades are constructed and arranged to fully retract within said hollow shaft until said blade moving mechanism urges them out said side openings such that said cutting blades are not in a cutting position until desired.
9. The expandable reamer of claim 8 wherein said elongated shafts of said blade members are rectangular in cross-section and abut against each other within said hollow shaft to increase torsional rigidity.
10. The expandable reamer of claim 9 wherein the proximal ends of said elongated shafts of said blade members include notches which engage with an adjustment slide of said blade moving mechanism.
11. The expandable reamer of claim 10 wherein said adjustment slide is inserted through a side access port which is covered by a locking cover.
12. The expandable reamer of claim 11 wherein said blade members are spring steel and constructed and arranged to have a slip fit within the hollow shaft such that the blade members may be inserted into said hollow shaft through said side openings while limiting movement of said blade members within said shaft.
13. An expandable reamer comprising:
- a) an elongated shaft having a proximal end and a distal end, a pair of blade members pivotally engaged to the distal end of the elongated shaft, a pair of elongated blade guides positioned immediately adjacent to the elongate shaft, the elongate blade guides each having a guide slot, at least a portion of each of the pair of blade members being operatively engaged to one of the guide slots;
- b) an elongate hollow tube, the elongate hollow tube being disposed substantially about the elongated shaft and the pair of elongated blade guides, the elongate hollow tube being longitudinally moveable relative to the elongated shaft;
- c) a handle, the handle having a hollow engagement barrel and at least one griping member extending therefrom, the hollow engagement barrel having a first end engaged to the elongate hollow tube, and a second end having a control knob, the control knob being operatively engaged to the elongate hollow tube, whereby when the control knob is rotated the elongate hollow tube is moved longitudinally relative to the elongated shaft causing the pair of blade members to move between a retracted position and an extended position.
14. An expandable reamer comprising:
- a) an elongated shaft having a proximal end and a distal end, a pair of blade members being pivotally engaged to the distal end of the elongated shaft, the distal end of the elongate shaft having a pair of blade slots constructed and arranged to slidingly and removably receive at least a portion of one of the blade members:
- b) an elongate hollow tube, the elongate hollow tube being disposed substantially about the elongated shaft, the elongated shaft being longitudinally moveable relative to the elongate hollow tube;
- c) a turn wheel, the turn wheel operatively engaged to the proximal end of the elongated shaft and positioned proximal to the elongate hollow tube, whereby when the turn wheel is rotated the elongated shaft is moved longitudinally relative to the elongate hollow tube causing the pair of blade members to move between a retracted position and an extended position.
15. An expandable reamer for use in bone and related tissue in a mammal comprising:
- an elongated hollow body having a proximal end and a distal end, sized and configured to engage bone and related tissue in the mammal;
- an elongated blade carrier having a proximal end and a distal end, the blade carrier disposed within the body;
- a set of blades pivotally attached proximate the distal end of the blade carriers; the set of blades having at least a first retracted position relative to the body, the body having a maximum cross-sectional diameter transverse to a longitudinal axis of the body that is substantially at least as large as a maximum cross-sectional diameter of the blades in the first retracted position, and a second fully expanded position having a diameter greater than the maximum cross-sectional diameter of the body; and
- an manually actuated activation mechanism that moves the set of blades from the first retracted position to the second fully expanded position and any expanded position therebetween.
16. The reamer of claim 15 wherein the body includes a view port.
17. The reamer of claim 15 wherein the blade carrier is linearly movable relative to the body and the body includes indicators that indicate a distance that the blade set is extended from the distal end of the body.
18. The reamer of claim 15 wherein the set of blades includes cam arms and the activation mechanism is a moveable cannulated shaft having linear movement along the body, the moveable cannulated shaft having cam surfaces that engage the cam arms of the set of blades such that the linear movement of the moveable cannulated shaft is translated to pivoting movement of the blade set thereby driving the blade set to the first expanded position.
19. The reamer of claim 18 wherein the cam arms are double sided such that reverse linear movement of the moveable cannulated shaft retracts the blade set into the first retracted position.
20. The reamer of claim 18 wherein the activation mechanism is a blade control knob constrained within the proximal end of the body, the blade control knob having rotational motion that actuates the moveable cannulated shaft such that the linear movement of the moveable cannulated shaft is translated to pivoting movement of the blade set thereby driving the blade set to the expanded position.
21. The reamer of claim 15 wherein the blades extend beyond the distal end of the hollow body.
22. The reamer of claim 15 wherein the blades are pivotally attached at a single pivot point.
23. The reamer of claim 15 wherein each of the blades includes a cutting portion arranged such that substantially all of the cutting portion is outside the maximum cross-sectional diameter of the body when the blades are in the second fully expanded position.
24. An expandable reamer for use in bone and related tissue in a mammal comprising:
- an elongated hollow body having a proximal end and a distal end including means for engaging bone and related tissue in the mammal,
- an elongated blade carrier having a proximal end and a distal end, the blade carrier disposed within the body;
- a set of blades pivotally attached proximate the distal end of the blade carrier, the set of blades having at least a first retracted position relative to the body, the body having a maximum cross-sectional diameter transverse to a longitudinal axis of the body that is substantially at least as large as a maximum cross-sectional diameter of the blades in the first retracted position, and a second fully expanded position having a diameter greater than the maximum cross-sectional diameter of the body; and
- n means for manually moving the set of blades from the first retracted position to the second fully expanded position and any expanded position therebetween.
25. The reamer of claim 24 wherein the body includes a view port.
26. The reamer of claim 24 wherein the blade carrier is linearly movable relative to the back and the body includes indicators that indicate a distance that the blade set is extended from the distal end of the body.
27. The reamer of claim 24 wherein the set of blades includes cam arms and the means for moving the set of blades is a moveable cannulated shaft having linear movement along the body, the moveable cannulated shaft having cam surfaces that engage the cam arms of the set of blades such that the linear movement of the moveable cannulated shaft is translated to pivoting movement of the blade set thereby driving the blade set to the expanded position.
28. The reamer of claim 27 wherein the cam arms are double sided such that reverse linear movement of the moveable cannulated shaft retracts the blade set into the first retracted position.
29. The reamer of claim 27 wherein the means for moving the blade set is a blade control knob constrained within the proximal end of the body, the blade control knob having rotational motion that actuates the moveable cannulated shaft such that the linear movement of the moveable cannulated shaft is translated to pivoting movement of the blade set thereby driving the blade set to the expanded position.
30. The reamer of claim 24 wherein the blades extend beyond the distal end of the hollow body.
31. The reamer of claim 24 wherein the blades are pivotally attached at a single pivot point.
32. The reamer of claim 24 wherein each of the blades includes a cutting portion arranged such that substantially all of the cutting portion is outside the maximum cross-sectional diameter of the body when the blades are in the second fully expanded position.
33. A method for creating a cavity in bone comprising:
- drilling a bore in bone,
- inserting an expandable reamer into the bore,
- manually actuating an activation mechanism of the reamer that engages a blade carrier within the reamer such that linear motion of the blade carrier drives a blade set pivotally attached to the blade carrier from a first retracted position relative to the body, the body having a maximum cross-sectional diameter transverse to a longitudinal axis of the body that is substantially at least as large as a maximum cross-sectional diameter of the blades in the retracted position to a second fully expanded position having a diameter greater than the maximum cross-sectional diameter of the body and any expanded position therebetween;
- contacting the bone with the blade set in the any expanded position; and
- rotating the expandable reamer such that the blade set cuts into the bone.
34. The method of claim 33 wherein the blades extend beyond the distal end of the hollow body.
35. An expandable reamer for use in bone and related tissue in a mammal comprising:
- an elongated hollow body having a proximal end and a distal end sized and configured to engage bone and related tissue in the mammal;
- at least one shaft operably arranged in a coaxial relation with the hollow body along a longitudinal axis and having a proximal and a distal end;
- a set of blades pivotally attached proximate the distal end of the shaft, the set of blades having at least a first retracted position relative to the body, the body having a maximum cross-sectional diameter transverse to a longitudinal axis of the body that is substantially at least as large as a maximum cross-sectional diameter of the blades in the first retracted position, and a second fully expanded position having a diameter greater than the maximum cross-sectional diameter of the body; and
- an manually actuated activation mechanism that moves the set of blades from the first retracted position to the second fully expanded position and any expanded position therebetween.
36. The reamer of claim 35 wherein the body includes a view port.
37. The reamer of claim 35 wherein the body includes indicators that indicate a distance that the blade set is extended from the distal end of the body.
38. The reamer of claim 35 wherein the set of blades includes cam arms and the activation mechanism is one of a pair of shafts having linear movement along the body, the shaft having cam surfaces that engage the cam arms of the set of blades such that the linear movement of the shaft is translated to pivoting movement of the blade set thereby driving the blade set to the expanded position.
39. The reamer of claim 38 wherein the cam arms are double sided such that reverse linear movement of the shaft retracts the blade set into the first retracted position.
40. The reamer of claim 38 wherein the activation mechanism is a blade control knob constrained within the proximal end of the body, the blade control knob having rotational motion that actuates one of the pair of shafts such that the linear movement of the shaft is translated to pivoting movement of the blade set thereby driving the blade set to the expanded position.
41. The reamer of claim 35 wherein the blades extend beyond the distal end of the hollow body.
42. The reamer of claim 35 wherein the blades are pivotally attached at a single pivot point.
43. The reamer of claim 35 wherein each of the blades includes a cutting portion arranged such that substantially all of the cutting portion is outside the maximum cross-sectional diameter of the body when the blades are in the second fully expanded position.
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Type: Grant
Filed: May 7, 2004
Date of Patent: Sep 27, 2011
Assignee: Spineology, Inc. (St. Paul, MN)
Inventors: Stephen D. Kuslich (Stillwater, MN), Patricia Kuslich, legal representative (Stillwater, MN), Francis Peterson (Spooner, WI), Todd Bjork (River Falls, WI), Joseph E. Gleason (Eagan, MN), Rodney Rogstad (Plymouth, MN)
Primary Examiner: Pedro Philogene
Attorney: Skaar Ulbrich Macari, P.A.
Application Number: 10/842,057
International Classification: A61B 17/00 (20060101);