Patent Publication Number: US-11660134-B2

Title: Instruments and methods for delivering bone cement to a bone screw

Description:
FIELD 
     Instruments and methods are provided for delivering bone cement to a bone screw. 
     BACKGROUND 
     Bone screws, such as pedicle screws, can be used in orthopedic surgery to fix bone during healing, fusion, or other processes. In spinal surgery, for example, bone screws can be used to secure a spinal fixation element to one or more vertebrae to rigidly or dynamically stabilize the spine. 
     In many instances, particularly in spinal surgeries, the patient may have diminished or osteoporotic bone quality, which lessens the purchase of bone screws in such bone structure. As a result, this can preclude stabilization of the vertebrae and can lead to bone screw loosening and pullout. To improve bone screw fixation, bone cement can be introduced into bone proximate to the bone screw. 
     Bone screw augmentation typically uses cannulated/fenestrated bone screws for injecting bone cement into the bone structure having the fenestrated bone screw therein. For example, once a cannulated/fenestrated bone screw is inserted into bone, a cannula and/or guide can be docked to the head assembly. The docked cannula and/or guide functions as an alignment guide to the shank of the bone screw and allows access to the shank&#39;s fenestration(s). As such, cement delivery is effected by inserting a cement delivery shaft through the docked cannula and/or guide and into the shank of the bone screw, and pumping bone cement through the shaft and into the shank of the bone screw. In use, however, coupling of the cannula and/or guide to the head assembly and securing proper alignment of the cannula and/or guide with the shank can be challenging, particularly where direct visualization of the bone screw is compromised. Clinically, this can hinder intraoperative stability, interfere with the procedural workflow, and increase the number of surgical steps. Moreover, since the cannula and/or guide functions as an alignment guide for cement delivery, insufficient coupling to the head assembly and/or misalignment with the shank of the bone screw can result in cement leakage or failure of the cement delivery shaft. 
     Accordingly, there remains a need for improved instrumentation and methods associated with delivering bone cement to a bone screw. 
     SUMMARY 
     Various instruments and methods are disclosed for delivering bone cement to a bone screw. 
     In one embodiment, an instrument is provided and includes a cannulated bone screw, a cannulated shaft and a retaining sleeve disposed around at least a portion of the cannulated shaft. The cannulated bone screw has a head that is configured to be received within a rod receiver, and a shank extending distally from the head and configured to extend distally from the rod receiver. The head has proximal and distal recesses therein. The cannulated shaft has a distal end that is configured to extend into the shank of the cannulated bone screw, and a proximal end that is configured to couple to a bone cement delivery system. The retaining sleeve has a distal end that is configured to couple to the proximal recess in the head of the bone screw. 
     In some embodiments, the instrument can include a coupling assembly that is configured to selectively couple the cannulated shaft to the retaining sleeve to prevent axial translation of the cannulated shaft relative to the retaining sleeve. 
     The coupling assembly can have a variety of configurations. In some embodiments, the coupling assembly can be coupled to the proximal end of the retaining sleeve. For example, a distal end of the coupling assembly can be threadably coupled to the proximal end of the retaining sleeve. 
     In some embodiments, the coupling assembly can include a release mechanism that can be configured to selectively disengage the cannulated shaft from the retaining sleeve. The release mechanism can have a channel extending therethrough, in which the channel can at least partially overlap with a lumen that extends through an annular body such that the coupling assembly can be disposed around a portion of the cannulated shaft. The coupling assembly can also include a biasing element that can bias the release mechanism toward a groove of the cannulated shaft. 
     The cannulated bone screw can have a variety of configurations. In some embodiments, the proximal recess of the cannulated bone screw can be threaded, and the distal end of the retaining sleeve can be threadably coupled to the threaded proximal recess. 
     In another exemplary embodiment, an instrument is provided having a cannulated bone screw, a cannulated shaft, and a guiding assembly that is partially disposed around the cannulated shaft. The cannulated bone screw has a head that is configured to couple to a rod receiver and a shank extending distally from the head, in which the head has proximal and distal recesses therein. The cannulated shaft has a distal end that is configured to extend into the shank of the bone screw, and a proximal end that is configured to couple to a bone cement delivery system such that bone cement can be delivered through the cannulated shaft and into the shank of the bone screw. The guiding assembly includes a guiding sleeve having a distal end that is configured to couple to the proximal recess in the head of the bone screw, and a locking mechanism that is configured to couple to a proximal end of the guiding sleeve. The locking mechanism is configured to selectively lock the cannulated shaft and the guiding sleeve together to inhibit longitudinal movement of the cannulated shaft relative to the guiding sleeve. In some embodiments, a distal end of the locking mechanism can be configured to threadably couple to the proximal end of the retaining sleeve. 
     The locking mechanism can have a variety of configurations. For example, in some embodiments, the locking mechanism can include a release mechanism that can be configured to selectively engage a groove of the cannulated shaft. The locking mechanism can include a biasing element that can bias the release mechanism toward the groove of the cannulated shaft. The locking mechanism can include an annular body having a first portion, a second portion, and a lumen extending therebetween, in which the release mechanism is partially housed within the first portion of the annular body. The release mechanism can have a channel extending therethrough, in which the channel at least partially overlaps with the lumen of the annular body. 
     Methods for delivering bone cement to a bone screw are also provided. In one exemplary embedment, the method can include implanting a cannulated bone screw into bone, in which the bone screw has a head that is configured to couple to a rod receiver and a shank extending distally from the head. The head has proximal and distal recesses therein, in which the proximal recess is threadably coupled to a distal end of a retaining sleeve on an instrument. The method can also include inserting a distal end of a cannulated shaft through the retaining sleeve and into the shank of the bone screw, and injecting cement through the cannulated shaft and into the shank of the bone screw. 
     In some embodiments, implanting the cannulated bone screw in bone can include rotating the retaining sleeve relative to a screw drive assembly on the instrument to threadably engage the distal end of the retaining sleeve to the proximal recess of the bone screw, rotating the screw drive assembly to drive the bone screw into bone, and removing the screw drive assembly from the instrument while the retaining sleeve remains threadably engaged to the bone screw. 
     In some embodiments, the proximal end of the retaining sleeve can be coupled to a coupling assembly having a release mechanism, in which inserting the distal end of the cannulated shaft can cause the release mechanism to engage with a portion of the cannulated shaft upon the distal end reaching a predetermined insertion depth within the bone screw. In such embodiments, the method can include disengaging the release mechanism from the cannulated shaft to allow the cannulated shaft to be translated in a proximal direction and removed from the bone screw. 
     In some embodiments, the method can include, prior to injecting the cement, coupling a proximal end of the cannulated shaft to a bone cement delivery system. In other embodiments, the method can include, after injecting cement, coupling a rod receiver to the head of the bone screw. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a perspective view of one embodiment of an instrument for delivering bone cement to screw; 
         FIG.  2    is a partial exploded view of the instrument of  FIG.  1   ; 
         FIG.  3 A  is a top view of the instrument of  FIG.  1   ; 
         FIG.  3 B  is a cross-sectional view of the instrument of  FIG.  3 A  taken at  3 - 3 ; 
         FIG.  4    is a magnified cross-sectional view of a portion of the instrument of  FIG.  3 B  taken at  4 ; 
         FIG.  5    is a magnified cross-sectional view of a portion of the instrument of  FIG.  3 B  taken at  5 ; 
         FIG.  6    is a cross-sectional view of an embodiment of a bone screw assembly; 
         FIG.  7    is a perspective view of another embodiment of an instrument for delivering bone cement to a bone screw; 
         FIG.  8    is a partial exploded view of the instrument of  FIG.  7   ; 
         FIG.  9 A  is a side view of the instrument of  FIG.  8   ; and 
         FIG.  9 B  is a cross-sectional view of the instrument of  FIG.  9 A  taken at  9 - 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the instruments and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the instruments, systems, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention. 
     Various surgical instruments and methods are provided for delivering bone cement to a bone screw. In some embodiments, the instruments and methods allow for driving a bone screw into bone, and thereafter maintaining a connection between the bone screw and the instrument. This connection can allow direct access to the implanted bone screw, e.g., for subsequent cement delivery, prior to attaching a rod receiver, e.g., a U-shaped rod receiver, to the head of the bone screw. Further, this connection can help control alignment with, and thus access to, the implanted bone screw. Cement delivery to the implanted bone screw can therefore be effected without the need to attach the rod receiver and dock a separate alignment guide thereto. As a result, this can provide intraoperative stability earlier on in the surgical procedure, streamline the procedure workflow, and reduce the number of surgical steps, and thus surgical time. 
     An exemplary instrument can include a variety of features to facilitate bone cement delivery to a bone screw, as described herein and illustrated in the drawings. However, a person skilled in the art will appreciate that the instruments can include only some of these features and/or can include a variety of other features known in the art. The instruments described herein are merely intended to represent certain exemplary embodiments. 
       FIGS.  1 - 5    illustrate one exemplary embodiment of an instrument  100  that is configured to deliver bone cement directly into a bone screw  102  prior to coupling a rod receiver (not shown) thereto. The illustrated instrument  100  generally includes a cannulated shaft  104 , a retaining sleeve  106 , also referred to herein as a guiding sleeve, disposed around a portion of the cannulated shaft  104 , and a coupling assembly  108 , also referred to herein as a locking mechanism. The guiding sleeve and the locking mechanism are collectively referred to herein as a guiding assembly. For purposes of simplicity, certain components of the instrument  100  are not illustrated in  FIGS.  1 - 3 B . 
     While the bone screw  102  can have a variety of configurations, the bone screw  102 , as shown in  FIGS.  1 - 3 B and  5   , has a head  112  and a shank  114  extending distally from the head  112 . The head  112  can have a variety of shapes and sizes. As shown, the head  112  is generally in the shape of a truncated sphere and includes proximal and distal recesses  116 ,  118  defined therein. The proximal recess  116  can be substantially cylindrical with internal threads  120  formed therein for engaging a corresponding threaded portion of the retaining sleeve  106 , as discussed below. The distal recess  118  can be shaped to non-rotatably engage a distal tip of a driver shaft (not shown), as discussed below. For example, the distal recess  118  can be in the form of a female mating feature (e.g., a hex recess) and the distal tip of the driver shaft can be in the form of a male mating feature (e.g., a hex protrusion) such that the distal tip of the driver shaft can mate to the bone screw  102 . In this illustrated embodiment, the head  112  includes a threaded proximal recess  116  and a non-threaded distal recess  118 . 
     Further, the head  112  is configured to be coupled to a rod receiver. In this way, once cement is delivered to the bone screw  102  and the instrument  100  is removed therefrom, as will be discussed in more detail below, the head  112  of the bone screw  102  is exposed for subsequent attachment to a rod receiver to form a bone screw assembly. An exemplary bone screw assembly  300  is illustrated in  FIG.  6   , in which a rod receiver  382  is attached to a head  312  of a cannulated bone screw  302 . While the rod-receiver  382  can have a variety of configurations, in this illustrated embodiment, the rod receiver  382  is substantially U-shaped. In other embodiments, the rod receiver  382  can have other suitable configurations, e.g., a rod receiver having an enclosed thru-hole or a substantially C-shaped rod receiver. In some embodiments, the bone screw assembly is polyaxial. A person skilled in the art will appreciate that the head of the cannulated bone screw can have other suitable shapes and sizes. Exemplary embodiments of suitable bone screws and bone screw assemblies are described in more detail in U.S. Patent Publication Nos. 2018/0014858 and 2018/0014862, each of which is hereby incorporated by reference in its entirety. 
     The shank  114  of the bone screw  102  can have a variety of shapes and sizes. As shown, the shank  114  is in the form of an elongated body with threads  124  formed on at least a portion of its exterior surface  126 . The illustrated shank  114  includes a lumen  128  extending entirely therethrough. In other embodiments, the lumen  128  can extend through only a portion of the shank  114 . The lumen  128  is in fluid communication with the proximal and distal recesses  116 ,  118  of the head  112 . As a result, a distal end  104   d  of the cannulated shaft  104  can be inserted through the head  112  of the bone screw  102  and into at least a portion of the shank  114 , as shown in  FIGS.  1 - 3 B and  5   , to allow bone cement to be delivered therethrough and into the bone screw  102 . The shank  114  can also include at least one fenestration  130 , e.g., aperture, extending outward from the lumen  128  to the exterior surface  126  of the shank  114 . At least one fenestration  130  is configured to direct bone cement that is injected into the bone screw  102  towards bone that is proximate to the bone screw  102 , e.g., when the bone screw  102  is implanted. The position and number of fenestrations within the shank  114  of the bone screw  102  can vary. 
     As shown in  FIGS.  1 - 3 B and  5   , the retaining sleeve  106  is coupled to the head  112  of the bone screw  102 . While the retaining sleeve  106  can have a variety of configurations, in this illustrated embodiment, the retaining sleeve  106  has an elongated, cylindrical shape that extends from a proximal end  106   p  to a distal end  106   d . The distal end  106   d  of the retaining sleeve  106  is configured to couple to the head  112  of the bone screw  102  to deliver bone cement subsequently thereto. The retaining sleeve  106  also includes a lumen  134  that is configured to receive components, e.g., a driver shaft for driving the bone screw  102  into bone, the cannulated shaft  104 , as shown in  FIGS.  1 - 3 B and  4   . In this illustrated embodiment, the lumen  134  extends from the proximal end  106   p  to the distal end  106   d  of the retaining sleeve  106  along the longitudinal axis (Li) of the instrument. As a result, the retaining sleeve  106  can function as a guide for the cannulated shaft  104 , which is inserted through the retaining sleeve  106  and into the coupled bone screw  102 , as shown in  FIGS.  1 - 3 B and  5   . This allows cement to be delivered into the bone screw  102  prior to attaching a rod receiver to the head  112  of the bone screw  102 . 
     The distal end  106   d  of the retaining sleeve  106 , as shown, includes threads  132  that are threadably engaged with the corresponding internal threads  120  of the proximal recess  116  of the head  112  of the bone screw  102 . As such, the retaining sleeve  106  is threadably coupled to the bone screw  102  itself. A person skilled in the art will appreciate that the retaining sleeve  106  and the bone screw  102  can be coupled to each other using other coupling mechanisms. For example, in other embodiments, the head of the bone screw can have an outer surface that is configured to couple to an inner surface of the retaining sleeve via a pressure fit (e.g. collet mechanism). 
     Further, as shown in  FIGS.  1 - 4   , the proximal end  106   p  of the retaining sleeve  106  is attached to the coupling assembly  108 . The proximal end  106   p  of the retaining sleeve  106  includes a proximal cavity  136  having internal threads  138  that are threadably engaged with a threaded portion of the coupling assembly  108 . The proximal end  106   p  also includes first and second channels  135 ,  137  that extend laterally through a wall  109  of the retaining sleeve  106  (e.g., orthogonally to the longitudinal axis (L I )of the instrument). The first and second channels  135 ,  137  are in communication with corresponding third and fourth channels  139 ,  140  that extend laterally through a wall  110  of the coupling assembly  108  (e.g., orthogonally to the longitudinal axis (L I ) of the instrument). In particular, the first and third channels  135 ,  139  are engaged via a first set pin  143  and the second and fourth channels  137 ,  140  are engaged via a second set pin  144 . In this way, during use, the retaining sleeve  106  and the coupling assembly  108  are prevented from unthreading from each other, and thus from decoupling. A person skilled in the art will appreciate that the retaining sleeve  106  and the coupling assembly  108  can be coupled to each other using other coupling mechanisms, or that the retaining sleeve  106  and the coupling assembly  108  may be formed together from a single continuous profile. 
     The coupling assembly can have a variety of configurations. The illustrated coupling assembly  108  includes an elongated annular body  146  having a proximal end  148 , a distal end  150 , and a lumen  152  extending therebetween, as shown in  FIGS.  1 - 4   . The lumen  152  extends along the longitudinal axis of the instrument (Li) and is in communication with the lumen  134  of the retaining sleeve  106 . As shown in  FIGS.  3 B and  4   , the distal end  150  includes outer threads  154  that are threadably engaged to the internal threads  138  of the proximal cavity  136  of the retaining sleeve  106 , and the third and fourth channels  139 ,  140  that are engaged with the first and second channels  135 ,  137  of the proximal cavity  136  via corresponding set pins  143 ,  144 . The proximal end  148  of the annular body  146  includes an aperture  156  extending radially outward from the lumen  152  and through an outer surface  146 a of the annular body  146 . 
     The coupling assembly can also include a release mechanism, e.g., a release button. As shown, the coupling assembly  108  includes a release button  158  that is partially housed within the proximal end  148  of the annular body  146 . While the release button  158  can have a variety of configurations, in this illustrated embodiment, the release button  158  is substantially rectangular in shape and includes a first portion  160   a  and a second portion  160   b . Further, a channel  161  extends from a first surface  159   a  to a second surface  159   b  of the release button  158 . As shown in  FIGS.  3 B and  4   , the channel  161  at least partially overlaps with the lumen  152  of the annular body  146 . As a result, the coupling assembly  108  is disposed around a portion of the cannulated shaft  104 , as shown in  FIGS.  1  and  3 A- 4   . 
     Further, the release button  158  is coupled to a biasing element  162  that is configured to bias the first portion  160   a  of the release button  158  toward the lumen  142  of the annular body  146  and the second portion  160   b  of the release button  158  away from the lumen  142  of the annular body. While the biasing element  162  can have a variety of configurations, the biasing element  162 , as shown in  FIGS.  2 ,  3 B and  4   , is in the form of a helical spring. 
     The coupling assembly  108  is configured to selectively couple components, e.g., a driver shaft of a screw drive assembly and the cannulated shaft  104 , as shown in  FIGS.  1  and  3 A- 4   , to the retaining sleeve  106 . In use, the bone screw  102  can be inserted into bone using a screw drive assembly (not shown) that is releasably coupled to the retaining sleeve  106  via the coupling assembly  108 . The screw drive assembly and the retaining sleeve  106  are collectively referred to herein as a screw inserter instrument. The screw drive assembly can include a handle and a driver shaft that is coupled to the handle. The driver shaft can be inserted through the retaining sleeve  106  to engage the distal recess  118  of the bone screw  102  and drive the bone screw  102  into bone. As such, the bone screw  102  can be coupled to the screw inserter instrument, for example, by inserting the distal tip of the driver shaft into the distal recess  118  of the head  112  of the bone screw  102  and threadably engaging the distal end  106   d  of the retaining sleeve  106  to the proximal recess  116  of the head  112  of bone screw  102 . The bone screw  102  can be driven into bone by rotating the screw drive assembly relative to the retaining sleeve  106 . Additional details on the screw drive assembly and other exemplary embodiments of screw inserter instruments can be found, for example, in U.S. patent application Ser. Nos. 16/440,602 and 16/440,618, filed on Jun. 13, 2019, entitled “Screw Inserter Instruments and Methods,” each of which is incorporated by reference herein in its entirety. 
     Once the bone screw  102  is inserted into bone, the screw drive assembly is decoupled (e.g., by depressing the second portion  160   b  of the release button  158  of the coupling assembly  108 ), and removed from the retaining sleeve  106 , and thus, the bone screw  102 , while the retaining sleeve  106  remains threadably engaged to the bone screw  102 . As a result, once the screw drive assembly is removed, the cannulated shaft  104  can be inserted into and coupled to the retaining sleeve  106  via the coupling assembly  108 , as shown in  FIGS.  1  and  3 A- 4   . In this way, the retaining sleeve  106  can function as an alignment guide that provides access to the bone screw after its insertion such that bone cement can be injected therein. This avoids the need to couple, e.g., thread, a separate alignment guide to the bone screw  102  to guide the cannulated shaft  104 , and thus bone cement, into the bone screw  102 . 
     While the cannulated shaft  104  can have a variety of configurations, the cannulated shaft  104 , as shown in  FIGS.  1 - 3 B , is in the form of a generally elongated hollow tube that extends from a proximal end  104   p  to a distal end  104   d  of the cannulated shaft  104 . The distal end  104   d  extends into a portion of the bone screw  102 . The proximal end  104   p  of the cannulated shaft  104  is configured to be coupled (e.g., threadably coupled) to a bone cement delivery system (not shown) such that bone cement can be delivered from the system, through the cannulated shaft  104 , and into the bone screw  102 . As will be appreciated by a person skilled in the art, any bone cement delivery system can be configured to couple to the cannulated shaft  104  to deliver bone cement therethrough. Exemplary embodiments of bone cement delivery systems can be found in U.S. Pat. Nos. 7,097,648, 8,360,629, 8,415,407, and 9,381,024, and U.S. Patent Publication Nos. 2006/0264967, 2007/0032567, 2008/0228192, and 2010/0114174, each of which is hereby incorporated by reference in its entirety. 
     As shown in  FIGS.  3 B and  4   , the cannulated shaft  104  is coupled to the retaining sleeve  106  via the coupling assembly  108 . In this illustrated embodiment, the release button  158  engages with a groove  105  of the cannulated shaft  104  adjacent to the proximal end  104   p  of the cannulated shaft  104 . In particular, the first portion  160   a  is configured to engage the groove  105 , and the second portion  160   b  is configured to be spaced from the groove  105  at a distance (D). This distance, as described in more detail below, can allow the second portion  160   b  to be selectively depressed towards the groove  105  so as to move the first portion  160   a  away from the groove  105 , thereby decoupling the cannulated shaft  104  and the retaining sleeve  106 . As shown in  FIG.  3 B , the release button  158  is engaged to the cannulated shaft  104  via the biasing element  162  in an extended configuration. As a result, the first portion  160   a  of the release button  158  is biased toward the groove  105  and the second portion  160   b  of the release button  158  is biased away from the groove  105  at distance (D). 
     In use, the cannulated shaft  104  is inserted into the retaining sleeve  106  until the first portion  160   a  of the release button  158  slides into contact with and engages the groove  105  of the cannulated shaft  104 . In this way, the distal end  104   d  of the cannulated shaft  104  is inserted into the bone screw  102  at a predetermined insertion depth. Once bone cement is delivered through the cannulated shaft  104  and into the bone screw  102  (e.g., when a desired amount of bone cement is injected into the bone screw), the cannulated shaft  104  can be removed from the retaining sleeve  106 . To remove the cannulated shaft  104  from the retaining sleeve  106 , the release button  158  can be actuated to cause the first portion  160   a  of the release button  158  to move away from, and thus disengage, the groove  105 . For example, a user can actuate the release button  158  by applying sufficient force to the second portion  160   b  thereof such that the second portion  160   b  moves towards the groove  105 . This causes the first portion  160   a  of the release button  158  to shift away from the groove  105  and the biasing element  162  to move into a compressed configuration. As a result, the first portion  160   a  of the release button  158  disengages the groove  105  of the cannulated shaft  104 , thereby allowing the cannulated shaft  104  to be slidably removed (e.g., translated in a proximal direction) from at least the bone screw  102 . 
       FIGS.  7 - 9 B  illustrate another embodiment of an instrument  200  that is configured to deliver bone cement to a bone screw  202 . Aside from the differences described in detail below, the instrument  200  is similar to instrument  100  shown in  FIGS.  1 - 4    and therefore common elements are not further described in detail herein. Further, for purposes of simplicity, certain components of the instrument  200  are not illustrated in  FIGS.  7 - 9 B . 
     In this illustrated embodiment, the instrument  200  includes an alignment guide  264 , a cannulated shaft  204  extending therethrough, and a coupling element  266  that is configured to releasably couple the cannulated shaft  204  to the alignment guide  264 . 
     Once the bone screw  202  is inserted into bone, the alignment guide  264  can be coupled to the head  212  of the bone screw  202 . The alignment guide  264  can have a variety of configurations. In this illustrated embodiment, the alignment guide  264  is in the form of a generally elongated hollow tube that extends from a proximal end  264   p  to a distal end  264   d . The distal end  264   d  includes a threaded portion  268   a  and a non-threaded portion  268   b  extending distally therefrom. The threaded portion  268   a  includes threads  269  that threadably engage with the corresponding internal threads  220  of the proximal recess  216  of the head  212  of the bone screw  202 , as shown in  FIGS.  7 - 9 B . The non-threaded portion  268   b  is formed within the distal recess  218  of the head  212  of the bone screw  202 . Further, the proximal end  264   p  of the alignment guide  264  includes an annular collar  270  having a connection feature  271  that is configured to engage with the coupling element  266 , as shown in  FIGS.  7 - 9 B . In this illustrated embodiment, the connection feature  271  is an annular groove or notch. In other embodiments, the connection feature  271  can have other configurations. 
     While the cannulated shaft  204  can have a variety of configurations, the cannulated shaft  204 , as shown, is in the form of a generally elongated hollow tube that extends from a proximal end  204   p  to a distal end  204   d . The distal end  204   d  extends into a portion of the bone screw  202 . Further, the cannulated shaft  204  includes a ferrule  272  that extends radially outward from an outer surface  273   a  of the cannulated shaft  204 . The ferrule  272  is interposed between a first segment  274   a  and a second segment  274   b  of the cannulated shaft  204 . The ferrule  272  can have a variety of shapes and sizes. In this illustrated embodiment, the ferrule  272  has a substantially conical shaped configuration. The ferrule  272  is configured to contact a tapered portion  275  of the inner surface  265  of the alignment guide  264  so as to limit the insertion depth of the distal end  204   d  of the cannulated shaft  204  into the bone screw  202 . As a result, this contact between the ferrule  272  and the tapered portion  275  can prevent a user from inserting the distal end  204   d  of the cannulated shaft  204  too far into, or entirely through, the bone screw  202 . 
     As shown, the coupling element  266  is fixedly attached to the cannulated shaft  204 . The coupling element  266  can have a variety of configurations. In this illustrated embodiment, the coupling element  266  includes a hollow tubular base member  276  with two spaced-apart arms  278 ,  280  extending radially outward therefrom. The distal end  276   d  of the tubular base member  276  is fixedly coupled to the proximal-most end  204   a  of the cannulated shaft  204 . The proximal end  276   p  of the tubular base member  276  is configured to be coupled (e.g., threadably coupled) to a bone cement delivery system (not shown) such that bone cement can be delivered from the system, through the tubular base member  276  and cannulated shaft  204 , and into the bone screw  202 . As will be appreciated by a person skilled in the art, any bone cement delivery system can be configured to couple to the tubular base member  276  to deliver bone cement therethrough. Exemplary embodiments of bone cement delivery systems can be found in previously mentioned U.S. Pat. Nos. 7,097,648, 8,360,629, 8,415,407, and 9,381,024, and U.S. Patent Publication Nos. 2006/0264967, 2007/0032567, 2008/0228192, and 2010/0114174, each of which is hereby incorporated by reference in its entirety. 
     Further, as shown in  FIGS.  7 - 9 B , the cannulated shaft  204  is releasably coupled to the alignment guide  264  via the two spaced-apart arms  278 ,  280  of the coupling element  266 . In particular, the distal end  278   d ,  280   d  of each arm  278 ,  280  engages with the connection feature  271  of the alignment guide  264 . In use, the distal ends  278   d ,  280   d  of the arms  278 ,  280  can either slide or snap into engagement with the connection feature  271 . To decouple the cannulated shaft  204  from the alignment guide  264 , the proximal ends  278   p ,  280   p  of the arms  278 ,  280  can be compressed together to cause the distal ends  278   d ,  280   d  to move away from each other and out of engagement with connection feature  271 . Once the distal ends  278   d ,  280   d  are disengaged, the cannulated shaft  204  can be removed. 
     The instruments disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the instrument can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the instrument, followed by cleaning or replacement of particular pieces and subsequent reassembly. In particular, the instrument can be disassembled, and any number of the particular pieces or parts of the instrument can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the instrument can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of an instrument can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned instrument, are all within the scope of the present application. 
     Further, in the present disclosure, like-named components of the embodiments generally have similar features, and thus within a particular embodiment each feature of each like-named component is not necessarily fully elaborated upon. Additionally, to the extent that linear or circular dimensions are used in the description of the disclosed systems, instruments, and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such systems, instruments, and methods. A person skilled in the art will recognize that an equivalent to such linear and circular dimensions can easily be determined for any geometric shape. Sizes and shapes of the systems and instruments, and the components thereof, can depend at least on the anatomy of the subject in which the systems and instruments will be used, the size and shape of components with which the systems and instruments will be used, and the methods and procedures in which the systems and instruments will be used. 
     It will be appreciated that the terms “proximal” and “distal” are used herein with reference to a user, such as a clinician, gripping a handle of an instrument. Other spatial terms such as “front” and “rear” similarly correspond respectively to distal and proximal. It will be further appreciated that for convenience and clarity, spatial terms such as “vertical” and “horizontal” are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these spatial terms are not intended to be limiting and absolute. 
     Values or ranges may be expressed herein as “about” and/or from/of “about” one particular value to another particular value. When such values or ranges are expressed, other embodiments disclosed include the specific value recited and/or from/of the one particular value to another particular value. Similarly, when values are expressed as approximations, by the use of antecedent “about,” it will be understood that there are a number of values disclosed therein, and that the particular value forms another embodiment. It will be further understood that there are a number of values disclosed therein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. In embodiments, “about” can be used to mean, for example, within 10% of the recited value, within 5% of the recited value or within 2% of the recited value. 
     For purposes of describing and defining the present teachings, it is noted that unless indicated otherwise, the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. 
     One skilled in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety. Any patent, publication, or information, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this document. As such the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference.