Abstract:
Methods and apparatus for treating bones, including, in one or more embodiments, a device for delivering a bone filler material comprising: a housing having a throughbore; a plunger comprising a shaft having external threads, wherein the plunger is configured for advancement through the throughbore of the housing; and a threaded receiving member configured to releasably engage the plunger. Methods for removing an instrument from a vertebral body comprising applying ultrasonic energy to the instrument, wherein a distal end of the instrument is disposed in a cavity in the vertebral body, wherein the cavity contains a filler material; and removing the instrument from the vertebral body.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/036,934 filed Sep. 25, 2013, which is a divisional of U.S. patent application Ser. No. 12/813,712 filed on Jun. 11, 2010, which issued as U.S. Pat. No. 8,568,420, the contents of these applications being incorporated herein by reference in their entireties for all purposes. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present disclosure generally relates to treatment of bones. In particular, in one or more embodiments, the present disclosure relates to a device for delivering bone filler material that includes a plunger and a threaded receiving member configured to releasably engage the plunger. 
       BACKGROUND OF THE INVENTION 
       [0003]    Bones and bony structures are susceptible to a variety of weaknesses that can affect their ability to provide support and structure. Weaknesses in bony structures may have many causes, including degenerative diseases, tumors, fractures, and dislocations. By way of example, weaknesses in vertebrae can lead to compression fractures that involve the collapse of one or more vertebrae in the spine. These vertebral compression fractures may be caused by a number of conditions including osteoporosis, trauma, and tumors. Advances in medicine and engineering have provided doctors with a plurality of devices and techniques for alleviating or curing these weaknesses. 
         [0004]    One technique for treating vertebral fractures is vertebroplasty. In vertebroplasty, a physician may use a needle to inject filler material (e.g., bone cement) into a fractured vertebral body to stabilize the fracture. Kyphoplasty is another technique for treating vertebra fractures that involves insertion of a balloon into the fractured vertebra to restore the height of the vertebra. The balloon may then be removed followed by injection of filler material into the vertebral body to stabilize the fracture. 
         [0005]    A number of different devices have been developed for injection of filler material into fractured vertebrae. For example, syringe-type devices have been used that comprise a plunger and a chamber. The physician manually advances the plunger to eject filler material from the chamber. Drawbacks to syringe-type devices include problems generating the necessary pressure to eject the filler material in certain applications. Additional drawbacks include precisely controlling the volume of filler material ejected from the chamber. Mechanical devices have also been used for the injection of filler material that may include, for example, a housing that supports a cartridge containing bone cement. The mechanical devices further may include a plunger that forces the filler material from the cartridge. The ram may be activated by a trigger mechanism or screwing mechanism, for example. 
         [0006]    Thus, there is a need for methods and devices that can be used to deliver bone filler material. 
       SUMMARY OF THE INVENTION 
       [0007]    An embodiment may comprise a device for delivering a bone filler material. The device may comprise a housing having a throughbore. The device may further comprise a plunger comprising a shaft having external threads. The plunger may be configured for advancement through the throughbore of the housing. The device may further comprise a threaded receiving member configured to releasably engage the plunger. 
         [0008]    The features and advantages of the present invention will be readily apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    These drawings illustrate certain aspects of the present invention and should not be used to limit or define the invention. 
           [0010]      FIGS. 1-3  illustrate a device for delivering bone filler material in accordance with one embodiment of the present invention. 
           [0011]      FIG. 4  illustrates a plunger for use in a device for delivering bone filler material in accordance with one embodiment of the present invention. 
           [0012]      FIGS. 5-7  illustrate a device for delivering bone filler material in accordance with alternative embodiments of the present invention. 
           [0013]      FIGS. 8-10  illustrate a device for delivering bone filler material in accordance with alternative embodiments of the present invention. 
           [0014]      FIGS. 11-12  illustrate an actuator assembly for use in a device for delivering bone filler material in accordance with one embodiment of the present invention. 
           [0015]      FIGS. 13-14  illustrate a device for delivering bone filler material in accordance with alternative embodiments of the present invention. 
           [0016]      FIG. 15  illustrates a device for delivering bone filler material with a flexible extension tube connecting the device to a cannula in accordance with one embodiment of the present invention. 
           [0017]      FIG. 16  illustrates a device for delivering bone filler material with a rigid extension tube connecting the device to a cannula in accordance with one embodiment of the present invention. 
           [0018]      FIGS. 17-19  illustrate an embodiment of the present invention in which ultrasonic energy is used in the removal of a cannula from a vertebral body. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]      FIGS. 1-3  illustrate a device  10  for delivering a bone filler material in accordance with one embodiment of the present invention. As illustrated, the device  10  may include a plunger  12 , a housing  14 , and a handle  16 . In an embodiment, a tube  18  containing filler material may be coupled to the housing  14 . The plunger  12  may be advanced through the housing  14  to eject the filler material from the tube  18 . As will be discussed in more detail below, the plunger  12  may be advanced by rotation of the plunger  12  or by pushing the plunger  12  in the axial direction. 
         [0020]      FIG. 4  illustrates an embodiment of the plunger  12 . As illustrated, the plunger  12  generally has a proximal end  20  and a distal end  22 . In the illustrated embodiment, the plunger  12  may include a plunger handle  24  at the proximal end  20  of the plunger  12 . The plunger  12  may further include a shaft  26 . At least a portion of the shaft  26  may include external threads  28 . The plunger  12  may further include a stop  30  configured to displace filler material from the tube  18 , which may be located at the distal end  22  of the plunger. As illustrated, the stop  30  may have a larger external diameter than the shaft  26 . In an embodiment, the shaft  26  may extend from the plunger handle  24  to the stop  30 . 
         [0021]    Referring again to  FIGS. 1-3 , the housing  14  may include a throughbore  32  in accordance with one embodiment of the present invention. As illustrated, the throughbore  32  may extend from anterior face  34  to posterior face  36  of the housing  14 . In an embodiment, the plunger  12  may be advanced through the throughbore  32 . As illustrated, the housing  14  may further include chamber  38  in the interior of the housing  14  that intersects the throughbore  32 . Upper receiving member  40  and lower receiving member  42  may be disposed in the chamber  38 . Upper receiving member  40  may contain upper inner threads  44 , and lower receiving member may contain lower inner threads  46  such that the upper receiving member  40  and the lower receiving member  42  generally may form a threaded bore. The upper inner threads  44  and lower inner threads  46  may be complementary with and generally configured to mate with the external threads  28  on the plunger  12 . 
         [0022]    A recess  48  may be formed off of the chamber  38 . As illustrated, the recess  48  may be formed off a lower portion of the chamber  38 . Spring  50  may be disposed in the recess  48  with spring  50  extending from the recess  48  to engage the lower receiving member  42 . In an embodiment, spring  50  biases the lower receiving member  42  into engagement with the plunger  12  such that the lower inner threads  46  on lower receiving member  42  are in engagement with the external threads  28  on the plunger  12 . In the illustrated embodiment, actuator  52  extends from chamber  38  through the upper face  54  of the housing  14 . Actuator  52  may be engaged with the lower receiving member  42  such that when the actuator  52  is depressed the lower inner threads  46  disengage from the plunger  12 . When pressed, the actuator  52  should apply pressure to the spring  50  such that the spring  50  no longer applies sufficient pressure on the lower receiving member  42  for the lower inner threads  46  to engage exterior threads  28  of the plunger  12 . Accordingly, the exterior threads  28  of the plunger  12  may be considered to be releasably engaged with the lower inner threads  46  of the lower receiving member  42  because they can be disengaged without rotation of the plunger  12 . In other words, the lower receiving member  42  is configured to releasably engage the exterior threads  28  of the plunger  12 . 
         [0023]    Housing  14  further may include a slot  56  for engaging the tube  18 . The slot  56  may intersect the throughbore  32 . In general, the slot  56  may be configured to hold the tube  18  in axial alignment with the throughbore  32 . While  FIGS. 1-3  illustrate housing  20  as being generally rectangular in shape, it should be understood that the present invention encompasses other suitable configurations for housing  20 , including, for example, cylindrically shaped housings. 
         [0024]    The handle  16  may be coupled to the housing  14  in accordance with one embodiment of the present invention. As illustrated, the handle  16  may include a post  58  about which a handle grip  60  is disposed. In an embodiment, distal end  62  of the post  58  may be disposed through a lower face  64  of the housing  14  to secure the handle  16  to the housing  14 . 
         [0025]    The tube  18  may be coupled to the housing  14  in accordance with one embodiment of the present invention. As illustrated, the tube  18  may include a rim  66  that may be received by the slot  56 . The rim  66  generally should secure the tube  18  to the housing  14 . The tube  18  may further include a chamber  68  for receiving the filler material. The tube  18  further may include an exit port  70  through which the filler material may be ejected. In an embodiment, the tube  18  may be constructed from a clear, plastic material. In an embodiment, the tube  18  may be disposable. It should be understood, that the device  10  may be supplied without the tube  18  in accordance with embodiments of the present invention. For example, the tube  18  containing the filler material may be supplied by the physician prior to use. 
         [0026]    To eject filler material from the exit port  70  of the tube  18 , the plunger  12  can be advanced through the housing  14  and into the tube  18 . As the plunger  12  advances through the tube  18 , filler material may be displaced out through the exit port  70 . The plunger  12  can be axially pushed or rotated through the housing  14  to advance into the tube  18  in accordance with present embodiments. In an embodiment, the plunger  12  can be moved along the longitudinal axis  72  of the throughbore  32  by rotating the plunger  12  such that the exterior threads  28  of the plunger  12  engage the upper and lower interior threads  44 ,  46  of the upper and lower receiving members  40 ,  42 . The plunger handle  24  may be used to facilitate rotation of the plunger  12 . In another embodiment, the plunger  12  can be advanced through the housing  14  and into the tube  18  by pushing the plunger  12  in the axial direction. Before the plunger  12  can be pushed in the axial direction, the actuator  52  should first be pushed to release lower interior threads  46  of the lower receiving member  42 . Otherwise engagement of the lower interior threads  46  with the exterior threads  28  of the plunger  12  will prevent movement of the plunger  12  in the axial direction without rotation. To retract the plunger  12  into the housing  14 , the plunger  12  can be axially pushed or rotated back through the housing  14  in a similar manner. 
         [0027]      FIGS. 5-7  illustrate device  10  for delivering a bone filler material in accordance with an alternative embodiment of the present invention. As illustrated, the device  10  may include plunger  12  and housing  14 . In an embodiment, the tube  18  containing filler material may be coupled to the housing  14 . As previously mentioned, the plunger  12  may be advanced through the housing  14  and into the tube  18  by rotation or axially pushing to eject the filler material. 
         [0028]    In the embodiment illustrated by  FIGS. 5-7 , the housing  14  includes a main body  73  and a handle portion  74  that extends from the main body  73 . The main body  73  may include a throughbore  32 . As illustrated, the throughbore  32  may extend from anterior face  34  to posterior face  36  of the main body  73 . In an embodiment, the plunger  12  may be advanced through the throughbore  32 . As illustrated, the housing  14  may further include an upper chamber  76  in the interior of the housing  14  that intersects the throughbore  32 . Receiving member  78  may be disposed in the upper chamber  76 . In the illustrated embodiment, receiving member  78  includes rod portion  80  and inner threaded portion  82 . Throughbore  32  may further contain upper threads  83  which generally may form a threaded bore with the inner threaded portion  82 . The inner threaded portion  82  and upper threads  83  may be complementary with and generally configured to mate with the external threads  28  on the plunger  12 . Receiving member  78  may translate within the upper chamber  76  from an engaged position to a disengaged position. In the engaged position, the inner threaded portion  82  of the receiving member  78  should engage the external threads  28  of the plunger  12 . In the disengaged position, the receiving member  78  should be positioned lower in the upper chamber  76  such that the inner threaded portion  82  is not engaged with the external threads  28  of the plunger  12 . 
         [0029]    Actuator rod assembly  84  may be mounted in the handle portion  74  of the housing  14 . Actuator rod assembly  84  has a proximal end  86  and distal end  88 . Actuator rod assembly  84  may comprise actuator rod  90 , actuator spring  92 , and actuator handle  94 . In the illustrated embodiment, the actuator rod  90  extends from the upper chamber  76  of the housing  14  out through the bottom  96  of the handle portion  74 . Actuator rod  90  may include threads  98  on the proximal end  86 , for example, that are in threaded engagement with the handle portion  74  of the housing  14 . Actuator spring  92  may be disposed over the actuator rod  90  on the distal end  88  of the actuator rod assembly  84  to engage the receiving member  78 . In an embodiment, actuator spring  92  biases the receiving member  78  into engagement with the plunger  12  such that the inner threaded portion  82  of the receiving member  78  is in engagement with the external threads  28  on the plunger  12 . In the illustrated embodiment, actuator handle  94  (e.g., a knob) is disposed on the proximal end of the actuator rod assembly  84 . Actuator handle  94  may be activated to lower the actuator rod  90  thereby releasing the pressure applied to the receiving member  78  by the actuator spring  92 . In this manner, the actuator handle  94  can be activated to disengage the inner treaded portion  82  of the receiving member  78  from the plunger. The actuator handle  94  may be activated, for example, by rotation. 
         [0030]    To eject filler material from the exit port  70  of the tube  18 , the plunger  12  can be advanced through the main body  73  of the housing  14  and into the tube  18 . As the plunger  12  advances through the tube  18 , filler material should be displaced out through the exit port  70 . The plunger  12  can be axially pushed or rotated through the housing  14  to advance into the tube  18 . In an embodiment, the plunger  12  can be moved along the longitudinal axis  72  of the throughbore  32  by rotating the plunger  12  such that the exterior threads  28  of the plunger  12  engage the inner threaded portion  82  of the receiving member  78  and upper threads  83  of the main body  73 . The plunger handle  24  may be used to facilitate rotation of the plunger  12 . In another embodiment, the plunger  12  can be advanced through the housing  14  and into the tube  18  by pushing the plunger  12  in the axial direction. Before the plunger  12  can be pushed in the axial direction, the actuator rod assembly  84  should first be activated to release the inner threaded portion  82  of the receiving member  78 . Otherwise engagement of the inner threaded portion  82  with the exterior threads  28  of the plunger  12  will prevent movement of the plunger  12  in the axial direction without rotation. The actuator rod assembly  84  may be activated by rotation of the activator handle  94 , for example. To retract the plunger  12  into the housing  14 , the plunger  12  can be axially pushed or rotated back through the housing  14  in a similar manner. 
         [0031]      FIGS. 8-10  illustrate device  10  for delivering a bone filler material in accordance with an alternative embodiment of the present invention. As illustrated, the device  10  may include plunger  12 , housing  14 , and handle  16 . In an embodiment, tube  18  containing filler material may be coupled to the housing  14 . As previously mentioned, the plunger  12  may be advanced through the housing  14  and into the tube  18  by rotation or axially pushing to eject the filler material. 
         [0032]    In the embodiment illustrated by  FIGS. 8-10 , the housing  14  includes main body  73  and a receiving member  100  coupled to the main body  73 . The main body  73  may include a throughbore  32 . Receiving member  100  may be disposed in a slot (not illustrated) in the rear face  36  of the main body  73 . Receiving member  100  may comprise body  102 , trigger  104 , and spring  106 . Body  102  may comprise bore  108  that extends through the body  102 . As illustrated by  FIGS. 11-12 , the bore  108  may comprise a first threaded portion  110  and a second threaded portion  112 . In the illustrated embodiment, the first threaded portion  110  is in the upper portion of the bore  108  and the second threaded portion  112  is in the lower portion of the bore  108 . As illustrated, the first smooth flared section  120  may be opposite the first threaded portion, and the second smooth flared section  122  may be opposite the second threaded portion  112 . Referring again to  FIGS. 8-10 , spring  106  may be mounted in the housing  14 . The spring  106  should bias the first threaded portion  110  and the second threaded portion  112  into engagement with the plunger  12  such that first and second threaded portions  110 ,  112  are in engagement with the external threads  28  of the plunger  12 . When biased, the first and second threaded portions  110 ,  112  of bore  108  generally should form a threaded bore that is axially aligned with throughbore  32  of main body  73 . The first and second threaded portions  110 ,  112  may be complementary with and generally configured to mate with the external threads  28  on the plunger  12 . At least one fulcrum  114  may be attached to the body  102 . In the embodiment illustrated by  FIGS. 8-10 , the at least one fulcrum  114  is in the form of two pins that are disposed through at least one opening  116  in the main body  73  to engage the body  102 . Body  102  can pivot about the at least one fulcrum  114  against the biasing of the spring  106 . 
         [0033]      FIGS. 11-12  illustrate the receiving member  100  in more detail in accordance with one embodiment of the present invention. In the illustrated embodiment, a second protrusion  118  extends from the body  102 . As illustrated, the trigger  104  and the second protrusion  118  may be in the form of tabs extending from the body  102  giving the receiving member  100  a generally T-shaped cross section. Bore  108  may comprise a first threaded portion  110 . In the illustrated embodiment, the first threaded portion  110  is located on the upper portion in the first half of the bore  108 . Bore  108  may comprise a second threaded portion  112 . In the illustrated embodiment, the second threaded portion  112  is located on the lower portion in the second half of the bore  108 . As illustrated, the bore  108  may have a first smooth flared section  120  and a second smooth flared section  122 . First smooth flared section  120  may be in the lower portion in the first half of the bore  108 . Second smooth flared section  122  may be in the upper portion in the second half of the bore  108 . 
         [0034]      FIG. 11  illustrates the receiving member  100  with the body  102  biased by spring  106  ( FIG. 10 ) in accordance with one embodiment of the present invention. As illustrated, the first and second threaded portions  110 ,  112  should generally form a threaded bore that is axially aligned with throughbore  32  of main body  73  when biased. In this manner, the first and second threaded portions  110 ,  112  may be in engaged with the external threads  28  of the plunger  12  ( FIG. 10 ). The receiving member  100  may be considered in a receiving member in that the receiving member  100  is configured to receive the plunger  12  in certain embodiments. 
         [0035]      FIG. 12  illustrates the receiving member  100  with the body  102  pivoted against the biasing of the spring  106  ( FIG. 10 ) in accordance with one embodiment of the present invention. In an embodiment, the trigger  104  may be pressed against the spring  106  to pivot the body  102 . When pivoted, the first and second threaded portions  110 ,  112  generally should disengage from the external threads  28  of the plunger  12  ( FIG. 10 ) with the first smooth flared section  120  and the second smooth flared section  122  allowing axial translation of the plunger  12  without rotation. 
         [0036]    To eject filler material from the exit port  70  of the tube  18 , the plunger  12  can be advanced through the body  102  of the receiving member  100 , through the throughbore  32  of the main body  73 , and into the tube  18 . As the plunger  12  advances through the tube  18 , filler material should be displaced out through the exit port  70 . The plunger  12  can be axially pushed or rotated through the housing  14  to advance into the tube  18  in accordance with present embodiments. In an embodiment, the plunger  12  can be advanced through the receiving member  100  and the main body  73  by rotating the plunger  12  such that the exterior threads  28  of the plunger  12  engage the threaded bore formed by the first and second threaded portions  110 ,  112  in the bore  108 . The plunger handle  24  may be used to facilitate rotation of the plunger  12 . In another embodiment, the plunger  12  can be advanced into the tube  18  by pushing the plunger  12  in the axial direction. Before the plunger  12  can be pushed in the axial direction, the first and second threaded portions  110 ,  112  should be disengaged. Otherwise engagement of the first and second threaded portions  110 ,  112  of the bore  108  with the exterior threads  28  of the plunger  12  will prevent movement of the plunger  12  in the axial direction without rotation. To disengage the first and second threaded portions  110 ,  112 , the body  102  should be pivoted against the biasing of the spring  106 . For example, the trigger  104  can be pressed against the spring  106  to pivot the body  102  about the at least one fulcrum  114 . As the body  102  pivots the first and second threaded portions  110 ,  112  should disengage from the exterior threads  28  releasing the plunger  12  and allowing axial translation of the plunger  12  in the throughbore  32 . To retract the plunger  12  into the housing  14 , the plunger  12  can be axially pushed or rotated back through the housing  14  in a similar manner. 
         [0037]      FIGS. 13-14  illustrate device  10  for delivering a bone filler material in accordance with an alternative embodiment of the present invention. As illustrated, the device  10  may include plunger  12  and housing  14 . In an embodiment, the tube  18  containing filler material may be coupled to the housing  14 . As previously mentioned, the plunger  12  may be advanced through the housing  14  and into the tube  18  by rotation or axially pushing to eject the filler material. 
         [0038]    In the embodiment illustrated by  FIGS. 13-14 , the housing  14  may include a flanged end  124 , body  126 , and one or more wings  128 . The body  126  may include a throughbore  32  through which the plunger  12  may be advanced. In the illustrated embodiment, the body  126  is generally cylindrical in shape. The wings  128  are configured to project from the body  126  of the housing  14  when in a disengaged position, as illustrated by  FIG. 13 . The wings  128  may be considered a receiving member in that the wings  128  are configured to receive the plunger  12  when in an engaged position, as illustrated by  FIG. 14 . In an embodiment, the wings  128  contain interior threads  130  that are configured to releasably engage the exterior threads  28  of the plunger  12 . In general, the interior threads  130  on the wings  128  may be complementary with and generally configured to mate with the external threads  28  on the plunger  12 . Collar  132  may be disposed on the housing  14 . Collar  132  may be configured to move on the housing  14  to force the wings  128  into engagement with the plunger  12 .  FIG. 13  illustrates the wings  128  in a disengaged position in accordance with one embodiment of the present invention. As illustrated, the wings  128  may project away from the body such that the interior threads  130  do not engage the exterior threads  28  of the plunger  12 .  FIG. 14  illustrates the wings  128  in an engaged position in accordance with one embodiment of the present invention. As illustrated, the collar  132  may be slid over the wings  128  forcing the interior threads  130  into engagement with the exterior threads  28  of the plunger  12 . 
         [0039]    To eject filler material from the exit port  70  of the tube  18 , the plunger  12  can be advanced through the body  126  of the housing  14  and into the tube  18 . As the plunger  12  advances through the tube  18 , filler material should be displaced out through the exit port  70 . The plunger  12  can be axially pushed or rotated through the housing  14  to advance into the tube  18 . In an embodiment, the plunger  12  can be moved along the longitudinal axis  72  of the throughbore  32  by rotating the plunger  12  such that the exterior threads  28  of the plunger  12  engage the interior threads  130  of the wings  128 . The plunger handle  24  may be used to facilitate rotation of the plunger  12 . For the wings  128  to receive the plunger  12 , the wings  128  should be in the engaged position with the collar  132 , for example, applying pressure to the wings  128 . In another embodiment, the plunger  12  can be advanced through the housing  14  and into the tube  18  by pushing the plunger  12  in the axial direction. Before the plunger  12  can be pushed in the axial direction, the wings  128  should be in the disengaged position with the collar  132 , for example, slid off the wings  128  such that wings are released to project out from the body  126 . Otherwise engagement of the interior threads  130  with the exterior threads  28  of the plunger  12  will prevent movement of the plunger  12  in the axial direction without rotation. To retract the plunger  12  into the housing  14 , the plunger  12  can be axially pushed or rotated back through the housing  14  in a similar manner. 
         [0040]      FIG. 15  illustrates introduction of filler material into vertebral body  134  with device  10  in accordance with one embodiment of the present invention. As illustrated, cannula  136  may be inserted into cavity  138  in vertebral body  134 . Cannula  136  may provide an access corridor into the cavity  138 . Extension tube  140  may be coupled to the cannula  136 . In accordance with present embodiments, the extension tube  140  may be configured to allow physician to use the device  10  while staying out of the radiation field during fluoroscopy. Extension tube  140  may have a proximal end  142  and a distal end  144 . The distal end  144  of the extension tube  140  may be coupled to the cannula  136 . In an embodiment, the extension tube  140  may be a flexible tube. In an embodiment, the extension tube  140  may be a rigid tube, as illustrated by  FIG. 16 . As illustrated, the extension tube  140  may be bent. The proximal end  142  of the extension tube  140  may be coupled to the device  10 . As illustrated, the extension tube  140  may be coupled to the tube  18  containing filler material. In an embodiment, a luer fitting  146  couples the extension tube  140  to the tube  18 . To inject filler material into the vertebral body  134 , the plunger  12  may be advanced. The plunger  12  should force the filler material from the tube  18 , through the extension tube  140  and cannula  136 , and into the vertebral body  134 . As discussed above, the plunger  12  may be advanced by rotation of the plunger  12  or by pushing the plunger  12  in the axial direction. 
         [0041]    As previously mentioned, filler material (e.g., bone cement) can be injected into a vertebral body  134  and through a cannula  136  in accordance with embodiments of the present invention. In embodiments, the device  10  can be used to deliver the filler material. After the filler material has been introduced, the cannula  136  can be removed from the vertebral body  134 . However, removal of the cannula  136  can be problematic, for example, if the cannula  136  has become stuck on the cured filler material. Accordingly, embodiments of the present invention provide a technique of utilizing ultrasound to facilitate removal of the cannula  136  from the vertebral body  134 .  FIGS. 17-19  illustrate an embodiment for removing the cannula  136  from the vertebral body  134 . While the present discussion is directed to cannula  136  removal, it should be understood that ultrasound may be to facilitate removal of other instruments that may be used in a surgical procedure. 
         [0042]      FIG. 17  illustrates cannula  136  disposed in vertebral body  134  in accordance with one embodiment of the present invention. Cavity  138  in the vertebral body  134  contains filler material  141 . In accordance with present embodiments, the filler material  141  may have set to form a hardened mass in the cavity  138 . The distal end  148  of the cannula  136  extends into the filler material  141  that is present in the vertebral body  134 . 
         [0043]      FIG. 18  illustrates an embodiment of the present invention in which ultrasound energizer  143  is used to deliver ultrasonic energy to the cannula  136 . The ultrasound energizer  143  may be any of a variety of devices suitable for generating ultrasonic energy. As illustrated, an ultrasound adapter  145 , contacting the cannula  136 , may be coupled to the ultrasound energizer  143 . In the illustrated embodiment, the ultrasound adapter  145  includes an attachment end  147  for coupling the ultrasound adapter  145  to the cannula  136 . As illustrated, the attachment end  147  may be generally u-shaped for receiving the tubular-shaped cannula  136 . The ultrasound adapter  145  should generally transfer the ultrasonic energy created by the ultrasound energizer  143  to the cannula  136 . It is believed that the vibrations in the cannula from the ultrasonic energy should generate frictional energy and, thus, heat, softening the set filler material  141  to ease removal of the cannula  136 . 
         [0044]      FIG. 19  illustrates removal of the cannula  136  from the vertebral body  134  in accordance with one embodiment of the present invention. Once the filler material  141  has been softened from application of the ultrasonic energy to the cannula  136 , axial force may be applied to remove the cannula  136  from the filler material  141  in the vertebral body  134 . 
         [0045]    The preceding description describes the introduction of a filler material into a vertebral body in accordance with embodiments of the present invention. Those of ordinary skill in the art will appreciate that the filler material may comprise any of a variety of materials that may be utilized to, for example, fill and stabilize a vertebral body. Examples of suitable materials may include bone cements (e.g. polymethyl methacrylate), human bone graft and synthetic derived bone substitutes. 
         [0046]    In addition, the preceding description is directed, for example, to the introduction of a filler material into a vertebral body for the treatment of vertebral fractures. It should be understood that the present technique also may be used in other suitable treatments where a filler material is introduced into a bone. By way of example, embodiments of the present invention may be used to treat tibia plateau fractures, distal radius fractures, and cancellous fractures. 
         [0047]    While it is apparent that the invention disclosed herein is well calculated to fulfill the objects stated above, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art.