Patent Publication Number: US-2023141374-A1

Title: Bone screw inserters and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 63/277,153, filed on Nov. 8, 2021. The entire content of this application is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     This disclosure relates generally to surgical instruments and, more particularly, to devices and methods that can be utilized for delivery of bone screws or other implantable assemblies. 
     BACKGROUND 
     Bone anchor assemblies can be used in orthopedic surgery to fix bone during healing, fusion, or other processes. In spinal surgery, for example, bone anchor assemblies can be used to secure a rod or other spinal fixation element to one or more vertebrae to rigidly or dynamically stabilize the spine. Bone anchor assembly implantation can require the use of specialized drivers to advance a threaded shank component into bone. 
     In some cases, fenestrated bone anchor assemblies can be utilized in combination with the delivery of bone cement or other flowable materials to aid in setting and/or securing the component driven into bone. Fenestrated bone anchor assemblies can include a threaded shank having a lumen extending at least part of its length with a distal and/or side opening to allow flowable material to escape from the lumen. 
     Fenestrated bone anchor assemblies can require specific alignment guides to enable delivery of cement or other flowable material. In some cases an alignment guide can be configured to drive in a screw in addition to receive a cement delivery device. In such prior devices, however, a combined device is often considered single-use and/or lacks compatibility or consistency with other pre-existing hardware. 
     Moreover, in many cases the use of prior driver and cement delivery devices has required the performance of device setup in the surgical field. It can be advantageous to minimize assembly operations required in the surgical field and enable, for example, setup of an assembly at a “back table” away from the immediate surgical field that can be passed to a surgeon or other user in a ready-to-use configuration. 
     Accordingly, there is a need for improved instrumentation for use in inserting bone screw assemblies and delivering bone cement or other flowable materials thereto. There is a need for such improved instrumentation that address shortcomings of prior designs, e.g., providing a reusable insertion device capable of delivering flowable materials, working with pre- existing cement delivery devices, permits assembly outside a surgical field, etc. 
     SUMMARY 
     The present disclosure provides bone screw inserters and methods that address shortcomings in prior designs and provide unique advantages. Generally speaking, the devices disclosed herein can include bone screw drivers configured to apply torque to a threaded shank of a bone screw assembly and implant it into bone, as well as receive a cement delivery device to introduce bone cement or other flowable material through the threaded shank. Also disclosed are driver adapters that can be coupled to a driver in order to facilitate application of torque thereto during bone screw implantation. The driver adapter can be configured to accommodate a configuration of the driver necessary for coupling with a cement delivery device and can be configured to decouple or release from the driver after implanting a bone screw shank into bone in order to allow the subsequent use of a cement delivery device in combination with the driver. The disclosed drivers and driver adapters can be reusable and can employ a number of additional components to form various assemblies, including retaining and counter-torque sleeves, driving handles, etc. Further, the devices disclosed herein can be utilized in a manner that allows setup of a bone screw inserter assembly outside a surgical field, such that a completed assembly can be passed to a surgeon or other user for immediate use in driving a bone screw assembly into bone. 
     In one aspect, a surgical assembly is disclosed that includes a driver having a distal tip configured to couple with another component in a manner that prevents rotation therebetween, and a proximal driver body with a lumen extending from the proximal-most end of the driver to the distal-most end of the driver. The surgical assembly further includes a driver adapter having a distal adapter body and a proximal torque-receiving end. The driver adapter is coupled to the driver such that a portion of the proximal driver body is received within a distal-facing cavity of the distal adapter body. The driver adapter is also configured to impart rotational force to the driver and the distal adapter body includes a lock configured to prevent axial separation of the driver and the driver adapter. 
     Any of a variety of alternative or additional features can be included and are considered within the scope of the present disclosure. For example, in some embodiments, the driver adapter can include a lumen extending from a proximal-most end of the driver adapter to the distal-facing cavity. In certain embodiments, the lock can include one or more pivoting latches that interface with a groove formed on the driver. In some embodiments, the driver can include one or more flats formed on the proximal driver body that interface with one or more flats formed on an interior surface of the distal-facing cavity of the driver adapter. 
     In some embodiments, the surgical assembly can further include a retaining sleeve disposed over a portion of the driver. In certain embodiments, the retaining sleeve can include a threaded distal end configured to interface with a bone screw receiver head. Moreover, in some embodiments, the retaining sleeve can include a lock configured to prevent separation of the retaining sleeve and driver. The surgical assembly can further include a second sleeve disposed over a portion of the retaining sleeve. In some embodiments, the second sleeve can include a plurality of rigid extensions formed at a distal end thereof configured to be received between portions of a bone screw receiver head. In certain embodiments, the second sleeve can include a plurality of flexible extensions formed at a proximal end thereof configured to deflect and ride over one or more surface features formed on the retaining sleeve. The second sleeve can be configured to move between a distal position, in which the second sleeve is locked against rotation relative to a bone screw receiver head coupled to the retaining sleeve, and a proximal position, in which the second sleeve can rotate relative to the bone screw receiver head coupled to the retaining sleeve. 
     In some embodiments, the surgical assembly can include a driver handle coupled to the proximal torque-receiving end of the driver adapter. In certain embodiments, a surgical navigation array can be coupled to the driver adapter. 
     In another aspect, a surgical method is provided that includes inserting a driver through a lumen of a retaining sleeve such that a tip formed at a distal-most end of the driver interfaces with a drive feature formed on a shank of a bone screw assembly. The method further includes coupling the retaining sleeve to a receiver head of the bone screw assembly, and coupling a driver adapter to the driver such that a proximal portion of the driver is received within a distal- facing cavity of the driver adapter and the driver adapter is locked against axial separation from the driver. The method further includes rotating the driver adapter to impart corresponding rotation of the driver and the shank of the bone screw assembly. 
     The methods disclosed herein can include any of a variety of additional or alternative steps that are considered within the scope of the present disclosure. In some embodiments, for example, the method can further include coupling a driver handle to a proximal end of the driver adapter. In certain embodiments, the method can further include locking the driver against axial separation from the retaining sleeve. In some embodiments, rotation of the driver and the shank of the bone screw assembly can be relative to the retaining sleeve. 
     In some embodiments, the method can further include inserting the retaining sleeve through a lumen of a second sleeve. The method may further include inserting the retaining sleeve through the lumen of the second sleeve before coupling the retaining sleeve to the receiver head of the bone screw assembly. The method may further comprise moving the second sleeve between a distal position, in which the second sleeve is locked against rotation relative to the receiver head of the bone screw assembly, and a proximal position, in which the second sleeve can rotate relative to the receiver head of the bone screw assembly. 
     In certain embodiments, the method can further include coupling the retaining sleeve to the receiver head, inserting the driver through the lumen of the retaining sleeve, and coupling the driver adapter to the driver outside of a surgical field. 
     In some embodiments, the method can further include separating the driver adapter from the driver, coupling a bone cement delivery device to the driver, and delivering bone cement through the driver and the shank of the bone screw assembly. 
     In another aspect, a bone screw driver is disclosed that includes a distal tip and a proximal body. Further, a lumen extends from the proximal-most end of the bone screw driver to the distal-most end of the bone screw driver, and the tip is formed at a distal-most end of the bone screw driver and is configured to interface with a bone screw to impart torque thereto. Still further, the proximal body includes opposed flats formed thereon configured to allow application of torque to the bone screw driver, and the proximal body has a diameter greater than a distance between the opposed flats at a position distal to the opposed flats. 
     As with the various aspects and embodiments disclosed above, any of a variety of alternative or additional features can be included and are considered within the scope of the present disclosure. For example, in some embodiments, the bone screw driver can include a coupling feature formed at a location proximal to the opposed flats. The coupling feature can be configured to interface with a driver adapter in a manner that prevents axial separation of the bone screw driver and driver adapter. In certain embodiments, the coupling feature can include a groove formed around a circumference of the proximal body. 
     In some embodiments, the bone screw driver can include an intermediate portion extending between the distal tip and the proximal body portion, and the intermediate portion can have a diameter less than a diameter of the proximal body portion. In some embodiments, a first shoulder can be formed along the intermediate portion and a second shoulder can be formed along the intermediate portion at a position distal to the first shoulder. In certain embodiments, the second shoulder can include a tapered distal-facing surface. In some embodiments, the distal tip can have a diameter less than that of the intermediate portion. 
     In certain embodiments, the lumen can include at least one portion along its length with a tapering diameter. In some embodiments, a proximal-most portion of the proximal body can have a conical outer surface with a diameter that tapers toward the proximal-most end of the driver. 
     In another aspect, a bone screw driver adapter is disclosed that includes a distal adapter body and a proximal torque-receiving end. The distal adapter body has a diameter greater than the proximal torque-receiving end and defines a distal-facing cavity configured to receive a proximal portion of a bone screw driver. The bone screw driver adapter further includes a distal-facing surface within the cavity that includes a protrusion extending distally therefrom that is configured to be received within a lumen of the bone screw driver and impart torque thereto. The distal adapter body also includes a lock configured to engage with the proximal portion of the bone screw driver when received within the cavity to prevent axial separation of the bone screw driver and the bone screw driver adapter. 
     As with the aspects and embodiments disclosed above, any of a variety of alternative or additional features can be included and are considered within the scope of the present disclosure. For example, in some embodiments, the proximal torque-receiving end can include one or more flats configured to allow application of torque to the bone screw driver adapter. 
     In certain embodiments, the bone screw driver adapter can further include an intermediate portion extending between the distal adapter body and the proximal torque-receiving end. Further, the intermediate portion can have a diameter less than a diameter of the distal adapter body. In some embodiments, the bone screw driver adapter can include a lumen extending from a proximal-most end of the adapter to the distal-facing cavity. 
     In some embodiments, the lock can include one or more pivoting latches with a first end exposed along an outer surface of the distal adapter body and a second end extending into the distal-facing cavity. In some embodiments, the one or more pivoting latches can be biased to drive the second end radially inward within the distal-facing cavity. 
     In certain embodiments, the bone screw driver adapter can include a surgical navigation array mount disposed between the distal adapter body and the proximal torque-receiving end. 
     In some embodiments, the distal-facing cavity can include at least one opening formed therein that extends to an outer surface of the adapter body. In certain embodiments, the outer surface of the distal adapter body can include one or more flats formed thereon. In certain embodiments, the protrusion can include one or more flats formed thereon. In some embodiments, the protrusion can include a first portion having the one or more flats formed thereon and a second portion extending distal to the first portion and having a diameter less than a diameter of the first portion. 
     In another aspect, a bone screw driver is disclosed that includes a distal tip and a proximal body. Further, a lumen extends from the proximal-most end of the bone screw driver to the distal-most end of the bone screw driver. Still further, the tip is formed at a distal-most end of the bone screw driver and is configured to interface with a bone screw to impart torque thereto. The proximal-most portion of the lumen also includes one or more flat sidewall portions configured to allow application of torque to the bone screw driver. 
     As with the aspects and embodiments disclosed above, any of a variety of alternative or additional features can be included and are considered within the scope of the present disclosure. For example, in some embodiments, the diameter of the lumen can be greatest along the proximal-most portion having the one or more flat sidewall portions. 
     Any of the features or variations described herein can be applied to any particular aspect or embodiment of the present disclosure in a number of different combinations. The absence of explicit recitation of any particular combination is due solely to avoiding unnecessary length or repetition. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The aspects and embodiments of the present disclosure can 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 a bone screw inserter assembly according to the present disclosure coupled with one embodiment of a bone screw assembly; 
         FIG.  2    is an exploded view of the bone screw inserter assembly of  FIG.  1   ; 
         FIG.  3    is a perspective view of select components of the bone screw inserter assembly of  FIG.  1   ; 
         FIG.  4    is an exploded view of the select components shown in  FIG.  3   ; 
         FIG.  5 A  is a rear perspective view of the bone screw driver of the assembly shown in  FIG.  1   ; 
         FIG.  5 B  is a front perspective view of the bone screw driver of  FIG.  5 A ; 
         FIG.  5 C  is a side view of the bone screw driver of  FIG.  5 A ; 
         FIG.  6    is a longitudinal cross-sectional view of the bone screw driver of  FIG.  5 A ; 
         FIG.  7 A  is a rear perspective view of the driver adapter of the assembly shown in  FIG.  1   ; 
         FIG.  7 B  is a front perspective view of the driver adapter of  FIG.  7 A ; 
         FIG.  7 C  is another front perspective view of the driver adapter of  FIG.  7 A ; 
         FIG.  8    is an exploded view of the driver adapter of  FIG.  7 A ; 
         FIG.  9    is a longitudinal cross-sectional view of the driver adapter of  FIG.  7 A ; 
         FIG.  10    is another longitudinal cross-sectional view of the driver adapter of  FIG.  7 A  that is 90° offset from the view of  FIG.  9   ; 
         FIG.  11    is a perspective view of one embodiment of a driver handle according to the present disclosure; 
         FIG.  12 A  is a rear perspective view of the retaining sleeve of the assembly shown in  FIG.  1   ; 
         FIG.  12 B  is a front perspective view of the retaining sleeve of  FIG.  12 A ; 
         FIG.  13    is a longitudinal cross-sectional view of the retaining sleeve of  FIG.  12 A ; 
         FIG.  14    is an exploded view of the retaining sleeve of  FIG.  12 A ; 
         FIG.  15    is a perspective view of select components of the bone screw inserter assembly of  FIG.  1   ; 
         FIG.  16    is a longitudinal cross-sectional view of the select components shown in  FIG.  15    and also showing the second sleeve of the assembly of  FIG.  1   ; 
         FIG.  17 A  is a rear perspective view of the second sleeve of the assembly shown in  FIG.  1   , 
         FIG.  17 B  is a front perspective view of the second sleeve of  FIG.  17 A ; 
         FIG.  18    is a longitudinal cross-sectional view of the second sleeve of  FIG.  17 A ; 
         FIG.  19    is a side view of select components of the bone screw inserter assembly of  FIG.  1    with the second sleeve in a distal position; 
         FIG.  20    is a side view of select components of the bone screw inserter assembly of  FIG.  1    with the second sleeve in a proximal position; 
         FIG.  21    is a front perspective view of the bone screw driver of the assembly shown in  FIG.  1    coupled to one embodiment of a cement delivery device; 
         FIG.  22    is a side view of the bone screw driver and retaining sleeve of the assembly shown in  FIG.  1    coupled to one embodiment of a cement delivery device; 
         FIG.  23    is a rear perspective view of select components of the assembly shown in  FIG.  1    coupled to one embodiment of a cement delivery device; 
         FIG.  24 A  is partially-transparent rear perspective view of the threaded bone anchor shank and bone screw driver of the assembly shown in  FIG.  1    coupled to one embodiment of a cement delivery device; 
         FIG.  24 B  is a partially-transparent front perspective view of the components shown in  FIG.  24 A ; 
         FIG.  25    is a side view of one embodiment of a navigated bone screw driver and driver adapter assembly according to the present disclosure; 
         FIG.  26    is a side exploded view of the navigated bone screw driver and driver adapter of  FIG.  25   ; 
         FIG.  27 A  is a rear perspective view of one embodiment of a bone screw driver according to the present disclosure; 
         FIG.  27 B  is a front perspective view of the driver of  FIG.  27 A ; 
         FIG.  28    is a longitudinal cross-sectional view of the driver of  FIG.  27 A ; 
         FIG.  29    is a side exploded view of one embodiment of an assembly according to the present disclosure, including a bone screw driver, retaining sleeve, and second sleeve; 
         FIG.  30    is a side exploded view of another embodiment of an assembly according to the present disclosure, including a bone screw driver, retaining sleeve, and second sleeve; 
         FIG.  31    is a side view of another embodiment of a bone screw driver that can be utilized in connection with the assembly of  FIG.  30   ; 
         FIG.  32    is a perspective view of one embodiment of a bone screw inserter assembly according to the present disclosure; 
         FIG.  33    is an exploded view of the bone screw inserter assembly shown in  FIG.  32   ; 
         FIG.  34    is a perspective view of the retaining sleeve of the assembly shown in  FIG.  32   ; 
         FIG.  35    is a partially-transparent perspective view of the retaining sleeve shown in  FIG.  34   ; 
         FIG.  36    is a perspective view of bone screw driver of the assembly shown in  FIG.  32   ; 
         FIG.  37    is a detail rear perspective view of the bone screw driver shown in  FIG.  36   ; 
         FIG.  38    is a rear perspective view of the driver adapter of the assembly shown in  FIG.  32   ; 
         FIG.  39    is a front perspective view of the driver adapter shown in  FIG.  38   ; 
         FIG.  40    is a perspective view of one embodiment of a bone screw inserter assembly according to the present disclosure; 
         FIG.  41    is a perspective view of the bone screw driver and driver adapter shown in  FIG.  40    in a coupled configuration; 
         FIG.  42    is a perspective view of the bone screw driver and driver adapter shown in  FIG.  41    in a separated configuration; 
         FIG.  43    is a front view of the driver adapter shown in  FIG.  40   ; 
         FIG.  44    is a front perspective view of the driver adapter shown in  FIG.  43   ; 
         FIG.  45    is a partially-transparent longitudinal cross-sectional view of the driver adapter shown in  FIG.  43   ; 
         FIG.  46    is a rear perspective view of the bone screw driver shown in  FIG.  40   ; 
         FIG.  47    is a longitudinal cross-sectional view of the bone screw driver shown in  FIG.  46   ; and 
         FIG.  48    is a longitudinal cross-sectional view of the assembly shown in  FIG.  40   . 
     
    
    
     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 devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. The devices, systems, and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments. The features illustrated or described in connection with one 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 disclosure. Additionally, to the extent that linear, circular, or other dimensions are used in the description of the disclosed devices and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such devices and methods. Equivalents to such dimensions can be determined for different geometric shapes, etc. Further, like-numbered components of the embodiments can generally have similar features. Still further, sizes and shapes of the devices, and the components thereof, can depend at least on the anatomy of the subject in which the devices will be used, the size and shape of objects with which the devices will be used, and the methods and procedures in which the devices will be used. 
     Bone screw inserters and related methods are disclosed herein for implanting a bone screw or portion of a bone screw assembly into bone. In some embodiments, the devices disclosed herein can include bone screw drivers configured to apply torque to a threaded shank of a bone screw assembly and implant it into bone, as well as receive a cement delivery device to introduce bone cement or other flowable material through the threaded shank. Also disclosed are driver adapters that can be coupled to a driver in order to facilitate application of torque thereto during bone screw implantation. The driver adapter can be configured to accommodate a configuration of the driver necessary for coupling with a cement delivery device and can be configured to decouple or release from the driver after implanting a bone screw shank into bone in order to allow the subsequent use of a cement delivery device in combination with the driver. The disclosed drivers and driver adapters can be reusable and can employ a number of additional components to form various assemblies, including retaining and counter-torque sleeves, driving handles, etc. Further, the devices disclosed herein can be utilized in a manner that allows setup of a bone screw inserter assembly outside a surgical field, such that a completed assembly can be passed to a surgeon or other user for immediate use in driving a bone screw assembly into bone. 
       FIGS.  1  and  2    show one embodiment of a bone screw inserter assembly  100  according to the present disclosure coupled with one embodiment of a bone screw assembly  102 . The bone screw inserter assembly  100  can include a bone screw driver  104 , a driver adapter  106 , a retaining sleeve  108 , and a second sleeve  110 . The bone screw assembly  102  can be, for example, a polyaxial bone screw having a threaded implantable shank  112  and a receiver head  114  coupled to the shank and configured for polyaxial movement relative thereto. In other embodiments, a uniplanar bone screw assembly can be utilized in which a receiver head can move in a single plane with regard to the shank. Further, in some embodiments a monoaxial bone screw can be utilized wherein a receiver head is locked against movement relative to a shank or integrally formed therewith such that no movement is possible between the receiver head and shank portions of the screw. Any of a variety of bone screws or bone screw assemblies can be utilized with the inserters disclosed herein and the illustrated bone screw assembly  102  is one example. Further details regarding various bone screws and bone screw assemblies can be found in U.S. Pat. Nos. 7,087,057; 9,155,580; 10,039,578; 10,299,839; and 10,980,574. The entire contents of each of these patents are incorporated by reference herein. 
     The bone screw inserter assembly  100  can be utilized to implant a bone screw assembly into bone. In the illustrated embodiment, the retaining sleeve  108  can be threadably coupled to the receiver head  114  of the bone screw assembly  102 . The driver  104  can be inserted through the retaining sleeve  108  such that a distal driver tip engages with a drive feature formed on the proximal end of the threaded shank  112 . A driver adapter  106  can couple with a proximal end of the driver  104  to facilitate delivery of torque thereto via, e.g., a driver handle or other instrument that can couple to the driver adapter. In addition, the second sleeve  110  can be utilized to facilitate handling and, in some embodiments, to provide counter-torque to the receiver head  114  when torqueing the threaded shank  112  to drive it into bone. As explained in greater detail below and shown in  FIGS.  21  to  24 B , the driver adapter  106  can be decoupled from the driver  104  and a cement delivery device can be coupled to the driver in order to deliver bone cement or other flowable material through a lumen formed in the threaded shank  112  of the bone anchor assembly  102 . 
       FIGS.  3  and  4    illustrate select components of the bone screw inserter assembly of  FIG.  1   . In particular, these figures feature the driver  104 , driver adapter  106 , and retaining sleeve  108 .  FIGS.  3  and  4    also show the drive tip  302  formed at a distal-most end of the driver  104  and the threads  304  formed at a distal end of the retaining sleeve  108 . Depending on the particular application and bone screw being utilized, it can be possible to utilize an inserter assembly featuring all of the components illustrated in  FIGS.  1  and  2   , or a subset thereof, such as the assembly illustrated in  FIGS.  3  and  4   . For example, in some situations it may be possible to utilize solely a driver  104  and adapter  106 , such as when driving an implantable threaded shank of a bone anchor assembly where the receiver head  114  is coupled to the shank at the surgical site after implantation. 
       FIGS.  5 A to  6    illustrate the driver  104  in greater detail. While a variety of shapes and configurations are possible, in the illustrated embodiment the driver  104  includes a distal driver tip  302  and a proximal driver body  502 . In addition, there is a lumen  504  extending through the driver  104  from a proximal-most end to a distal-most end thereof. The driver body  502  can have a generally cylindrical shape with varying diameters. For example, in the illustrated embodiment the driver body  502  can include a reduced diameter section  506  extending proximally that includes one or more flats  508 , such as opposed flats shown in the figures, formed thereon. In some embodiments, the one or more flats  508  can extend an entire length of the driver body without being divided into different sections of varying diameter. An example embodiment of such a configuration is shown in  FIGS.  32 - 39    and described in more detail below. As explained in more detail below, the driver adapter  106  can include a distal-facing cavity configured to receive the reduced diameter section  506  therein, as well as one or more internally-facing flats within the cavity that can interface with the one or more flats  508  and allow the driver adapter  106  to impart torque to the driver  104 . In other embodiments, any of a variety of drive features can be integrated into the proximal driver body  502  to facilitate the delivery of torque thereto. For example, in some embodiments a large drive feature, such as a Torx® drive recess or other recess having one or more flat portions, can be formed in a proximal end of the driver body  502 , e.g., surrounding the lumen  504 . In such embodiments, a complementary drive feature can be formed on the driver adapter  106  to facilitate the delivery of torque to the driver  104  when the two components are coupled to one another. An example embodiment of such a configuration is shown in  FIGS.  40 - 48    and described in more detail below. 
     The driver body  502  can further include a coupling feature to facilitate coupling and selectively securing another component relative to the driver  104 . In the illustrated embodiment, the coupling feature can include a groove  510  formed around an outer circumference of the driver body  502  at a location proximal to the opposed flats. As explained in more detail below, the coupling feature can be utilized by a lock of the driver adapter  106  to secure the two components relative to one another, and similarly can be utilized by a cement delivery device to couple with the driver  104  for delivery of cement through the lumen  504  of the driver. The driver body  502  can also include a conical proximal-most portion  512  that includes a diameter that tapers toward the proximal-most end of the driver  104 . This conical profile can be used to help position another component, such as the driver adapter  106  or a cement delivery device, when coupling with the driver  104 . In some embodiments, the conical surface can also be utilized in conjunction with the groove  510  to facilitate securing components relative to one another. 
     The illustrated embodiment of a driver  104  also includes an intermediate portion  514  extending between the distal driver tip  302  and the proximal body  502 . The intermediate portion  514  can have a generally cylindrical shape and can have varying diameters and lengths according to the particular application, etc. In the illustrated embodiment, for example, there can be one or more transitions or shoulders  516  formed by different diameters along a length of the intermediate portion  514 . The one or more transitions or shoulders can have tapered conical surfaces or stepped surfaces that are perpendicular to one another. For example, in the illustrated embodiment a first shoulder  518  is formed along the intermediate portion  514  along with a second shoulder  520  at a position distal to the first shoulder. As explained in more detail below, the first and second shoulders  518 ,  520  define a length  519  of the intermediate portion  514  that can receive a lock of the retaining sleeve  108  in order to prevent unintended axial separation of the driver  104  and retaining sleeve  108  while permitting relative rotation therebetween. Further, the second shoulder  520  can include a tapered distal-facing surface and a stepped proximal-facing surface, which can facilitate the lock of the retaining sleeve  108  riding over the shoulder  520  as the driver  104  is inserted into the retaining sleeve but prevent separation without specific release of the retaining sleeve lock. 
       FIG.  5 B  illustrates the driver tip  302  in greater detail. In the illustrated embodiment, the driver tip  302  is a T27 shape configured to be received within a drive recess of complementary shape formed on a proximal end of the threaded shank  112  of a bone anchor assembly  102 . In other embodiments, however, any of a variety of alternative driver tip shapes can be utilized. Also in the illustrated embodiment, the driver tip  302  has a diameter that is less than the intermediate portion  514  and the proximal body portion  502 . 
     As noted above, the driver  104  is cannulated and includes a lumen  504  extending along its length to facilitate delivery of bone cement or other flowable material therethrough. The lumen  504  can also facilitate the delivery of the driver  104 , and any bone screw assembly coupled thereto, over a guidewire. The lumen  504  have a variety of diameters based on intended application, and can also include one or more transitions  602  between different diameters along its length. As with the transitions or shoulders described above with regard to the outer surfaces of the driver  104 , the transitions  602  can include conical or tapered surfaces, or stepped surfaces that form shoulders perpendicular to the sidewalls of the lumen  504 . In some embodiments, the use of tapered or conical transition surfaces can help guide devices inserted through the lumen, such as an elongate tube associated with a cement delivery device, as described in more detail below and show in  FIGS.  21 - 24 B . 
     The driver  104  allows for delivery of a bone screw shank using, for example, the driver adapter  106  prior to delivery of bone cement or any other flowable material. As explained in more detail below, the driver adapter  106  can facilitate the attachment of a driver handle or other drive actuator to the driver  104 . After removing the driver adapter  106 , the cannulated driver  104  can allow the delivery of cement therethrough without requiring removal of the device or positioning of any additional components to facilitate introduction of a cement delivery device. 
       FIGS.  7 A- 10    illustrate the driver adapter  106  in greater detail. The driver adapter  106  can include a proximal end  702  configured to receive torque from a drive handle or other drive actuator. The proximal end  702  can include, for example, one or more flats  704  that can be utilized to impart torque to the driver adapter  106  and any components coupled thereto, such as the driver  104 . In the illustrated embodiment, the proximal end  702  includes two pairs of opposed flats  704  forming a square drive feature, though other configurations are possible in other embodiments. The proximal end can also include a groove  705  formed around a circumference thereof. As explained in more detail below, this can be utilized in some embodiments to facilitate securing a driver handle or other drive actuator to the driver adapter  106 . 
     The driver adapter  106  can also include a distal adapter body  706 . The distal adapter body  706  can have a diameter greater than the proximal torque-receiving end  702  and can define a distal-facing cavity  708  that can be configured to receive a portion of the driver  104 , such as the reduced diameter proximal portion  506  of the driver body  502 . The adapter body  706  can also include one or more flats  710  formed on an outer surface thereof, which can be utilized in certain embodiments to aid in torqueing the driver adapter  106  or otherwise coupling other instrumentation thereto in a manner that prevents relative rotation therebetween. Still further, the adapter body  706  can include one or more openings  711  formed therein and extending between an outer surface of the adapter body and the distal-facing cavity  708 . These openings can facilitate user visualization into the cavity  708  during coupling or release operations, as well as cleaning and sterilization of the driver adapter  106 , etc. 
     The distal-facing cavity  708  can include interior sidewalls that feature one or more flats  712 . In the illustrated embodiment, there are opposed flats  712  configured to interface with or abut against the opposed flats  508  formed on the portion of the driver  104  that can be received within the distal-facing cavity  708 . The interface of the one or more flats  712 ,  508  on the driver adapter  106  and driver  104  can allow torque applied to the driver adapter to transfer to the driver and, in turn, torque a bone screw shank coupled to the driver by the driver tip  302 . 
     The distal adapter body  706  of the driver adapter  106  can also include a lock configured to prevent axial separation of the driver and the driver adapter. For example, a lock can be configured to engage with a proximal portion of a bone screw driver when received within the cavity  708  to prevent removal of the driver from the cavity. Any of a variety of locks can be utilized, including locks making use of various latches, threads, grooves, magnetic or electromagnetic attraction forces, etc. The lock can include one or more pivoting latches  714 , such as the opposed latches  714  shown in the illustrated embodiment. The one or more latches  714  can each be configured to pivot around a pin  716  and can each include a first end  718  exposed along an outer surface of the distal adapter body  706  and a second end  720  extending into the distal-facing cavity  708 . The one or more latches  714  can each be biased to drive the second end radially inward within the distal-facing cavity in some embodiments. For example, a coil spring  722  or other biasing element can apply a force to each of the one or more latches  714  in a direction that urges the second end  720  to pivot radially inward into the cavity  708 . In use, as a proximal portion of the driver  104  is received in the distal-facing cavity  708  of the driver adapter  106 , the second end  720  of each of the one or more latches  714  can ride over the conical surface  512  and ultimately extend into the groove  510 . This can secure the driver  104  against axial separation from the adapter  106  until a user urges the first end  718  of each of the one or more latches radially inward to free the second end from the groove. 
     The driver adapter  106  can also include an intermediate portion  724  extending between the proximal torque-receiving end  702  and the distal adapter body  706 . The intermediate portion  724  can have a variety of lengths, shapes, and diameters. In the illustrated embodiment, the intermediate portion  724  is a generally cylindrical body having a diameter less than the diameter of the distal adapter body  706 . As explained in more detail below, in some embodiments the intermediate portion can include mounting points or other features configured to facilitate coupling with other components, such as surgical navigation arrays, etc. 
     In some embodiments, the driver adapter  106  can include a lumen  726  extending along a length thereof. For example, the lumen  726  can extend from a proximal-most end of the driver adapter  106  to the distal-facing cavity  708 . Inclusion of such a lumen can allow, for example, the use of the inserter assembly  100  in combination with a guidewire, etc. 
       FIG.  11    illustrates one embodiment of a driver handle  1100  that can be coupled to the proximal torque-receiving end  702  of the driver adapter  106  in order to allow a user to impart torque to the driver adapter, as well as a driver  104  and bone screw shank  112  that may be coupled thereto. The driver handle  1100  can have a distal end defining a distal-facing cavity  1102  configured to receive the proximal end of the driver adapter  106 . The cavity  1102  can include one or more flats complementary in shape to the one or more flats  704  formed on the driver adapter  104  in order to facilitate the transmission of torque therebetween. The driver handle  1100  can also include a lock  1104  formed along a distal portion thereof that can be utilized to secure a coupling between the driver handle and a driver adapter. For example, the lock  1104  can include a radially-translatable pin that can be urged into the groove  705  formed near the proximal end of the driver adapter  106  in order to prevent unintended separation of the components. 
     The driver handle  1100  can further include a user-graspable handle  1106  at a proximal end thereof to facilitate a user gripping the handle and applying torque thereto. Various shapes and sizes of handles can be utilized. In the illustrated embodiment, a T-handle shape is utilized. In addition, the driver handle  1100  can include a lumen  1108  formed from a proximal-most end thereof to the distal-facing cavity  1102 . This can be utilized in connection with the lumens formed in other components described herein, to allow use of an inserter assembly  100  in connection with a guidewire, etc. 
     While a user-graspable handle  1100  is shown in  FIG.  11   , it is also possible to couple any of a variety of other driver actuators to the proximal end of the driver adapter  106  to impart torque thereto. For example, an alternative driver such as a ratchet or a powered driver such as a drill/driver can be coupled to the square drive or other drive feature formed at the proximal end of the driver adapter  106 . In certain embodiments, a user-graspable handle or other driver component can be integrated into the driver adapter to create a single component with these features that cannot be separated from one another. 
       FIGS.  12 A- 14    illustrate the retaining sleeve  108  in greater detail. The retaining sleeve  108  can be a generally elongate cylindrical body and can include a distal end  1202  with threads  1204  formed thereon configured to engage with threads formed on an inner surface of a receiver head  114  of a bone screw assembly  102 . The retaining sleeve  108  can also include a proximal portion  1206  having a greater diameter than the distal end  1202 . The proximal portion  1206  can include a series of ridges  1208  or other surface features to facilitate a user grasping the retaining sleeve and imparting torque thereto, e.g., when coupling or decoupling the retaining sleeve with the bone screw receiver head  114 . 
     The retaining sleeve  108  can include a lumen  1210  extending from its proximal-most end to its distal-most end to facilitate passing one or more instruments, such as the driver  104 , therethrough. The retaining sleeve  108  can further include a lock configured to prevent separation of the retaining sleeve and, e.g., a driver inserted through the lumen  1210 . The lock can include a button  1212  disposed within the proximal portion  1206  and capable of radial translation. A coil spring  1302  or other bias element can urge the button  1212  in one direction and a pin  1214  extending through a sidewall of the proximal portion  1206  can ride within a slot  1402  formed in the button  1212  to limit its range of motion. The button  1212  can include a through-hole  1304  formed therein that can be sized to receive the driver  104 . As explained in more detail below and shown in  FIG.  16   , the button  1212  can ride over the shoulder  520  of the driver  104  as the driver is inserted through the lumen  1210  of the retaining sleeve  108 . After passing the shoulder  520 , the button  1212  can be urged by the spring  1302  in a manner that prevents separation of the driver  104  and the retaining sleeve  108  unless a user depresses the button  1212  against the biasing force of the spring  1302 . 
     Similar to other components described herein, the retaining sleeve  108  can include an intermediate portion  1216  extending between the distal end  1202  and the proximal portion  1206 . The intermediate portion  1216  can have a variety of shapes, lengths, and sizes, and can include one or more transitions of diameter or size along its length. Such transitions can feature tapered or conical surfaces for a gradual change in diameter or size, or steps that form perpendicular shoulders and instant changes in diameter or size. In addition, the intermediate portion can include one or more surface features that can be utilized to couple with additional components. For example, a ridge  1218  can be formed around a circumference of the retaining sleeve  108  at a location that facilitates desired positioning of a second sleeve that can be disposed over the retaining sleeve, as explained in more detail below. 
       FIGS.  15  and  16    illustrate select components of the inserter assembly  100  of  FIG.  1   .  FIG.  15   , for example, shows the coupling of the retaining sleeve  108  to the receiver head  114  of the bone screw assembly  102 , as well as the coupling of the driver  104  to the retaining sleeve and the threaded shank  112  of the bone screw assembly.  FIG.  16    shows a cross-sectional view of the components shown in  FIG.  15   , but also illustrates the second sleeve  110  of the assembly  100 . As can be seen in these figures, the retaining sleeve  108  can be coupled to the receiver head  114  of the bone anchor assembly  102  using threads  1602  formed on an internal surface of the receiver head and the threads  1204  formed at the distal end  1202  of the retaining sleeve  108 . The retaining sleeve  108  can be disposed over a portion of the driver  104  such that the driver tip  302  of the driver is received within a complementary-shaped drive recess  1604  formed in the threaded shank  112  of the bone anchor assembly  102 . Further, the driver  104  can be constrained relative to the retaining sleeve  108  by virtue of the lock button  1212  being positioned along the length  519  of the driver between the shoulders  518 ,  520 . Separation of the driver  104  from the retaining sleeve  108  will be prevented until the lock button  1212  is moved against the bias force of the spring  1302  to allow the shoulder  520  to pass through the bore formed in the button. 
     The length  519  of the driver between the shoulders  518 ,  520  can be greater than the length of the lock button  1212 , as in the illustrated embodiment, to facilitate some axial translation between the driver  104  and the retaining sleeve  108  when coupled. This can allow the retaining sleeve  108  to be rotated into or out of engagement with the threads of the receiver member  114  while the driver  104  remains in contact with the shank  112 . Alternatively, the retaining sleeve  108  can be threaded into the receiver member  114  while the driver  104  is held proximally relative thereto (e.g., such that a proximal face of the shoulder  520  abuts the button  1212 ), which will slowly bring the driver tip  302  of the driver into engagement with the drive recess  1604  as the retaining sleeve is threaded further into the receiver member. In other words, allowing some degree of axial translation between the retaining sleeve  108  and the driver  104  when coupled can allow assembly with a bone screw in either a “driver first” or “retaining sleeve first” manner, thereby providing flexibility to surgeons and other users working with the components. 
     Also shown in  FIG.  16    is the second sleeve  110 . This sleeve is illustrated in greater detail in  FIGS.  17 A to  20   . The second sleeve  110  is a generally cylindrical body configured to be disposed over a portion of the retaining sleeve  108 . The second sleeve  110  incudes a lumen  1702  extending between its proximal and distal ends. In some embodiments where the sleeve is utilized to provide counter-torque when driving a screw, the second sleeve  110  can include one or more rigid extensions  1704  or tangs formed at a distal end thereof. In the illustrated embodiment, there are two opposed rigid extensions  1704 . The rigid extensions  1704  can be configured to extend into U-shaped recesses formed between opposed portions of the receiver head  114  of the bone anchor assembly  102 . At a proximal end of the second sleeve  110  are one or more flexible extensions  1706  configured to deflect and ride over one or more surface features formed on the outer surface of the retaining sleeve  108 . In the illustrated embodiment, the four flexible extensions  1706  are formed by four relief slots  1708  cut into the sidewall of the second sleeve  110 . Further, a groove  1710  can be formed along an inner circumference of the second sleeve  110  and configured to receive a surface feature formed on an outer surface of the retaining sleeve  108 , such as the ridge  1218  discussed above. In the illustrated embodiment, the groove  1710  is formed along an inner circumference of the lumen  1702  across each of the flexible extensions near a proximal end of the second sleeve  110 . 
     In use, the second sleeve  110  can be disposed over a portion of the retaining sleeve  108  and can be moved between a distal position, as shown in  FIG.  19   , and a proximal position, as show in  FIG.  20   . In the distal position of  FIG.  19   , the rigid extensions  1704  can extend into the U-shaped recesses formed by opposed portions of the receiver member  114  or, if the rigid extensions are not present, a distal end of the sleeve  110  can abut a proximal end of the receiver member. In embodiments including the rigid extensions, disposing the sleeve  110  in the distal position can lock the sleeve against rotation relative to the receiver member due to interference between the rigid extensions  1704  and the receiver member  114 . In such a configuration, a user can grasp the second sleeve  110  and use it to apply counter-torque in one direction when applying torque to the driver  104  (e.g., via a driver adapter  106  and driver handle  1100  coupled thereto) in a second direction. 
     When the second sleeve  110  is not in use, it can be translated proximally from the position shown in  FIG.  19    to the position shown in  FIG.  20   . In the position shown in  FIG.  20   , the rigid extensions  1704  (if present) can be withdrawn proximally beyond a proximal-most end of the receiver member  114  such that they can rotate relative to the receiver member  114  without interference. In addition, in the position of  FIG.  20    the groove  1710  formed on the interior surface of the flexible extensions  1706  can be disposed over the ridge  1218  such that the second sleeve  110  is retained in the proximal position until sufficient force is applied by a user to cause the flexible extensions to deflect over the ridge and advance distally. In other embodiments, the second sleeve  110  can be rotatably coupled to the retaining sleeve  108 , such as by the use of threads formed on an inner surface of the sleeve that can interface with threads formed on an outer surface of the retaining sleeve. 
     The various components of the inserter assembly  100  described above can enable a user to setup the assembly and couple it to a bone screw assembly  102  for implantation in bone. Advantageously, such assembly can be performed outside a surgical field, such as on a “back table” or other preparation area adjacent the surgical field. This can reduce complexity of operation and the number of people operating within the surgical field. For example, in some embodiments, a user can couple a driver  104  to a retaining sleeve  108  by inserting the driver  104  through the lumen  1210  of the retaining sleeve. If a second sleeve  110  is to be utilized, it can be disposed over the retaining sleeve  108 . The user can also couple the retaining sleeve  108  to a bone anchor assembly  100  by engaging the threads  1204  of the retaining sleeve with the threads  1602  of the receiver member  114 . In addition, the user can couple the driver  104  to the threaded shank  112  by inserting the driver tip  302  of the driver into the drive recess  1604  of the shank  112 . Further, a user can couple a driver adapter  106  to the driver  104  by inserting the proximal end of the driver into the distal-facing cavity  708  of the driver adapter until the latches  714  engage to secure the components relative to one another. A user can also couple the driver handle  1100  to the proximal end of the driver adapter  106  by, for example, inserting the proximal end of the driver adapter into the distal-facing cavity  1102  of the driver handle  1100 . Coupling these components can create an assembly that is ready to pass from a preparation or staging area to a user in the surgical field who can immediately utilize the assembly to drive the shank  112  into bone. Further, if introduction of the shank  112  into bone is to be done over a guidewire, the lumens provided through the assembly  100  can enable passing the guidewire through the device and proceeding with guided delivery. 
     Note that a number of variations in order of coupling are possible with the assembly  100 , and it is possible to utilize only select components in some embodiments. For example, a user can elect to couple the driver handle  1100  to the driver adapter  106  at any time, and also to couple these components to the driver  104 . Further, the retaining sleeve  108  can be coupled to the receiver member  114  prior to insertion of the driver  104  therethrough, or the driver  104  can be coupled to the retaining sleeve  108  prior to coupling with the receiver member and/or shank  112 . Similarly, the driver  104  can be inserted into the drive feature of the shank  112  prior to threadably engaging the retaining sleeve  108  to the receiver member  114 , or the opposite order of coupling can be employed. 
     Once a shank  112  of a bone screw assembly  102  is implanted into bone, it can be desirable in some embodiments to deliver bone cement or other flowable material through a lumen  1606  formed in the shank (see  FIG.  16   ). The bone cement or other flowable material can flow out of the shank  112  through an opening  1608  formed at a distal end thereof and/or through one or more openings formed in a sidewall of the shank (not shown). In such embodiments, a cement delivery device  2102  can be coupled to the driver  104  as shown in  FIGS.  21  to  24 B . The proximal portion of the driver  104  can be configured to engage with the cement delivery device  2102  using features that also facilitate coupling with the driver adapter  106 , such as the groove  510  or other coupling feature and/or conical surface  512 . Accordingly, to deliver bone cement or other flowable material after implanting a bone screw shank  112 , a user can decouple the driver adapter  106  from the driver  104  by, for example, squeezing the first ends  718  of the pivoting latches  714  to release the second ends  720  from the groove  510  and permit proximal withdrawal of the driver adapter  106  relative to the driver  104 . 
     With the proximal end of the driver  104  exposed, a cement delivery device  2102  can be inserted through the lumen  504  of the driver  104  such that a distal cement delivery cannula  2104  of the device  2102  extends beyond the distal end of the driver and into the lumen  1606  of the shank  112 .  FIG.  21    illustrates the cement delivery device  2102  and driver  104  in isolation, while  FIG.  22    illustrates the cement delivery device  2102  and driver  104  in combination with the retaining sleeve  108 .  FIG.  23    illustrates the components of  FIG.  22    in addition to the bone screw assembly  102  and the second sleeve  110 .  FIGS.  24 A and  24 B  illustrate the cement delivery device, driver  104 , and shank  112  in partially transparent isolation to show the positioning of the cement delivery cannula and flow path of bone cement or other flowable material. 
     As shown in  FIGS.  21  to  24 B , the cement delivery device  2102  can interface with the driver  104  with resilient clips  2106  that engage with the groove  510  formed in the driver in a manner similar to the latches  714  of the driver adapter  106 . The cement delivery device  2102  also includes an inlet  2106  that can be coupled to a syringe or other device for introducing cement or other flowable material through the cement delivery cannula  2104 , into the lumen  1606  of the shank  112 , and out the one or more openings  1608  formed in the shank. One advantage of the devices and methods disclosed herein is that they can be configured for use with pre-existing cement delivery devices such that no changes or special adapters are needed during an operation. For example, the devices and methods disclosed herein can be compatible with cement delivery devices utilized to deliver Vertecem® and Confidence® bone cements from DePuy Synthes. Additional details regarding cement delivery devices like those that can be utilized in connection with the devices and methods disclosed herein can be found in U.S. Pat. No. 9,265,548, the entire contents of which are incorporated by reference herein. 
     The devices and methods disclosed herein can therefore provide a number of advantages over prior devices because a single driver can be utilized to both implant a bone screw assembly into bone and deliver bone cement or other flowable material without requiring the removal of the driver to replace with a different component. The modular driver adapters disclosed herein can allow a single driver that can interface with various cement delivery devices directly and with various torque drivers via the driver adapter. In addition, the devices disclosed herein can be reusable in nature, as they can be removed, disassembled, cleaned, and sterilized. 
       FIGS.  25  and  26    illustrate an alternative embodiment of a driver adapter  2502  that can be coupled with a driver  104 . The driver adapter  2502  can operate in a similar manner to the driver adapter  106  described above. In addition, however, the driver adapter  2502  can include a surgical navigation array mount  2602  disposed along the intermediate portion  2504  between the proximal torque-receiving end  2506  and the distal adapter body  2508 . The surgical navigation array mount can facilitate the coupling of a surgical navigation array  2510  to the driver adapter  2502  in a rigid manner, such that a surgical navigation system can track the three-dimensional position of the surgical navigation array in order to track the three-dimensional position of the driver adapter  2502 . Providing a navigated driver adapter  2502  and coupling it to the remainder of an inserter assembly, like the assembly  100  described above, can allow surgically navigated implantation of bone screw assemblies, with all of the accompanying advantages in precision and accuracy of placement associated therewith. The surgical navigation array mount  2602  can utilize any of a variety of surgical navigation array mount configurations and can be placed at any location along the driver adapter  2502  depending on clearance requirements for other components, etc. 
     While the description above focuses on one embodiment of a bone screw inserter assembly  100 , other embodiments are also envisioned that can include any of a variety of variations or modifications. For example, in some embodiments it can be possible to reverse the various device configurations shown and described above. In some embodiments, for example, a bone screw driver can include a cavity formed in a proximal end thereof that receives a distal portion of the driver adapter. Further, in some embodiments a proximal portion of the bone screw driver can include a lock configured to aid in coupling with a distal portion of the driver adapter and preventing axial separation of the driver and the driver adapter. Any such variations or modifications to the embodiments particularly shown and described above are considered within the scope of this disclosure. 
       FIGS.  27 A- 31    illustrate alternative embodiments of bone screw inserters that do not utilize the modular separable driver and driver adapter configuration described above. In these embodiments, a single or unitary bone screw driver can be utilized in connection with the remainder of the components described above, such as the retaining sleeve, counter-torque sleeve, and driver handle discussed in connection with the assembly  100 .  FIGS.  27 A- 28    illustrate one embodiment of a driver  2702  in detail. The driver  2702  can have a generally elongate, cylindrical shape and can include a distal driver tip  2704  and proximal torque-receiving end  2706 . These components can be substantially similar to the driver tip  302  of the driver  104  and proximal torque-receiving end  702  of the driver adapter  106  discussed above. The driver  2702  can also include an intermediate portion extending between its proximal and distal ends that can have varying lengths and include one or more surface features formed thereon, including changes in diameter, ridges, shoulders, flats, etc. In the illustrated embodiment, the driver  2702  includes three shoulders  2708 ,  2710 ,  2712  formed thereon. These shoulders can define two lengths  2714 ,  2716  that can receive a lock of a retaining sleeve to constrain a relative position of the driver  2702  relative to the retaining sleeve, as explained in more detail below. 
     The driver  2702  can also include a lumen  2718  extending along its length. The lumen  2718  can facilitate use of a guidewire to insert bone screws, as well as the delivery of flowable materials in cases where the size of the lumen  2718  is acceptable and the advantages of the above-described modular and separable driver and driver adapter are not needed. 
       FIG.  29    illustrates the driver  2702  in connection with a retaining sleeve  2902  and a second sleeve  2904 . The retaining sleeve  2902  can be substantially similar to the retaining sleeve  108  discussed above, and the second sleeve  2904  can be substantially similar to the second sleeve  110  discussed above. The lengths of the driver  2702 , retaining sleeve  2902 , and second sleeve  2904  can be coordinated to provide desired operation. The view of this figure also highlights how the lock  2906  of the retaining sleeve  2902  can be received within either of the lengths  2714 ,  2716  defined by the various shoulders  2708 ,  2710 , and  2712 . In some embodiments, the sizes and positions of the lengths  2714 ,  2716  can be configured to allow the driver  2702  to work in connection with different types of bone screw assembly receiver heads. In particular, the lengths  2714 ,  2716  can be positioned to allow the driver  2702  to correctly interface with a threaded shank when the retaining sleeve  2902  is coupled to either a standard height receiver head, like the receiver head  114  discussed above, and also with a receiver head having extended reduction tabs that extend the length of the threads formed on the receiver head. More details on one embodiment of such a receiver head can be found in U.S. Pat. No. 10,463,402 (e.g., in  FIG.  5 A ), the entire contents of which are incorporated by reference herein. 
       FIG.  30    illustrates another embodiment of an assembly including a driver  3002 , retaining sleeve  3004 , and second sleeve  3006 . These components can be substantially similar to those shown in  FIG.  29   , but can have different lengths. Any of a variety of different lengths, diameters, or other shapes can be utilized in forming the various components of a bone screw inserter assembly according the particular bone screw being inserted, area of anatomy being accessed, or other particular application parameters. 
       FIG.  31    illustrates still another embodiment of a driver  3102  that can be similar to either of the drivers  2702 ,  3002 , but can further include a surgical navigation array mount  3104  disposed along a length thereof. The surgical navigation array mount  3104  can be positioned along a proximal portion of the driver  3102  such that it remains proximal to a retaining sleeve when the driver is inserted through the retaining sleeve. The surgical navigation array mount  3104  can be similar to the surgical navigation array mount  2602  discussed above and can facilitate coupling with a surgical navigation array  3106  to allow navigated insertion of bone screw assemblies. 
       FIGS.  32 - 39    illustrate another example embodiment of a bone screw inserter assembly  3200  according to the present disclosure. The assembly  3200  can be similar in many ways to the assembly  100  described above and the description below provides details regarding certain differences between these embodiments. Note that any of the various features illustrated in connection with any embodiments disclosed herein can be combined with other embodiments. The assembly  3200  includes a driver  3202 , driver adapter  3204 , retaining sleeve  3206 , and second sleeve  3208 . 
       FIGS.  34  and  35    illustrate the retaining sleeve  3206  in greater detail. The retaining sleeve  3206  operates similarly to the retaining sleeves described above, including the use of a lock  3502  to couple the retaining sleeve to a driver. In addition, the retaining sleeve  3206  includes one or more recesses  3402  formed along an outer sidewall thereof. The one or more recesses  3402  can receive an end of a shaft or portion of another leverage multiplying instrument to facilitate separating the retaining sleeve  3206  from a receiver member in the event removal by gripping the body directly is difficult. 
       FIGS.  36  and  37    illustrate the driver  3204  in greater detail. The driver  3202  operates similarly to the drivers described above. In the illustrated embodiment, however, the driver  3202  includes a lower profile proximal body  3602  having one or more flats  3604  formed thereon. In particular, the body  3602  can have an outer surface with a constant diameter along its length that the one or more flats  3604  are formed into. This can, for example, provide an uninterrupted surface  3702  of a single diameter along the length of the proximal body  3602  along areas between adjacent edges of the one or more flats  3604 . Further, while the one or more flats  3604  in the illustrated embodiment are shown extending part-way along a length of the proximal body  3602 , in some embodiments the one or more flats can be formed to extend along an entire length of the proximal body. 
       FIGS.  38  and  39    illustrate the driver adapter  3204  in greater detail. The driver adapter  3204  operates similarly to the driver adapters described above. An interior of the distal-facing cavity  3902  of the driver adapter  3204  can include one or more flats  3904  configured to interface with the one or more flats  3604  of the driver when the two components are coupled to one another. 
       FIGS.  40 - 48    illustrate another example embodiment of a bone screw inserter assembly  4000  according to the present disclosure. The assembly  4000  can be similar in many ways to the assembly  100  described above and the description below provides details regarding certain differences between these embodiments. Note that any of the various features illustrated in connection with any embodiments disclosed herein can be combined with other embodiments. The assembly  4000  includes a driver  4002 , driver adapter  4004 , retaining sleeve  4006 , and second sleeve  4008 .  FIG.  40    illustrates the assembly  4000  coupled to a bone screw assembly  102  as well. 
       FIGS.  41  and  42    illustrate the driver  4002  and driver adapter  4004  in greater detail.  FIG.  41    shows the two components coupled with one another such that the one or more latches  4102  lock the two components against axial separation and the driver adapter  4004  can be utilized to impart torque to the driver  4002 .  FIG.  42    shows the driver  4002  axially separated from the driver adapter  4004 . Also visible is a protrusion  4202  extending from the distal-facing cavity  4204  of the driver adapter  4004  that can be utilized to align the two components and impart torque therebetween, as explained in more detail below. 
       FIGS.  43 - 45    illustrate the driver adapter  4004  in greater detail. The driver adapter  4004  can be similar in many ways to the driver adapters described above. As noted, however, the driver adapter  4004  can include a protrusion  4202  extending from a distal-facing surface  4302  of the distal-facing cavity  4204  of the driver adapter. The protrusion  4202  can be utilized to any of align the driver adapter  4004  with the driver  4002  and impart torque thereto. In particular, in some embodiments the protrusion  4202  can include a first portion  4304  having one or more flats  4306  formed thereon and a second portion  4308  extending distal to the first portion. In some embodiments, the second portion  4308  can have a diameter less than a diameter of the first portion  4304 . The protrusion  4202  and its various portions can have any of a variety of cross-sectional shapes, e.g., in the illustrated embodiment the first portion  4303  has a hexagonal cross-sectional shape while the second portion  4308  has a cylindrical or circular cross-sectional shape. In other embodiments, however, any of a variety of shapes can be utilized for the various portions (e.g., Torx® drive shapes, curved drive shapes, keyed drive shapes, etc.). In some embodiments, a protrusion  4202  can only include one of the portions described herein. In embodiments where the protrusion includes only a profile like that of the second portion  4308 , the distal-facing cavity  4202  can include one or more flats formed along other portions thereof to impart torque between the driver adapter and a driver, as described above. In embodiments where a protrusion includes features configured to impart torque to a driver, such as the first portion  4304  with one or more flats  4306 , the distal-facing cavity  4204  can have a substantially cylindrical outer sidewall, as shown in  FIGS.  43  and  44   . 
       FIGS.  46  and  47    illustrate the driver  4002  in greater detail. The driver  4002  can be similar in many ways to the drivers described above. The driver  4002 , however, can include a lumen  4602  having a proximal-most portion with one or more flat sidewall portions  4604 . In addition, in some embodiments, a diameter of the lumen along the proximal-most portion with the one or more flat sidewall portions  4604  can be greater than a diameter along other portions of the lumen. The proximal-most portion of the lumen  4602  can be configured to receive, for example, the first portion  4304  of the protrusion of the driver adapter  4004  such that the two components can be coupled in a manner that allows transmission of torque between the two components (e.g., prevents relative rotation between the components along a longitudinal axis thereof). In addition, a portion of the lumen  4602  distal to the above-described proximal-most portion can be configured to receive the second portion  4308  of the protrusion  4202  of the driver adapter  4004  in some embodiments. Extending a length of a first or second portion of a protrusion  4202  into a complementary lumen of the driver  4002  can aid more precise alignment between the components. Further, in the illustrated embodiment a proximal body  4606  of the driver  4002  can have a more rounded outer surface profile, e.g., a cylindrical outer surface or a surface having small flat portions formed thereon. This is because the outer surface of the proximal body  4606  is not utilized to transmit torque between the driver adapter  4004  and the driver  4002 . 
       FIG.  48    illustrates the coupling of the driver  4002  to the driver adapter  4004  and retaining sleeve  4006 . This includes the lock  3502  that can selectively prevent axial separation of the driver  4002  and the retaining sleeve  4006 , as well as the lock  4102  that can prevent axial separation of the driver and the driver adapter  4004 . Also visible is the interaction between the protrusion  4202  formed on the driver adapter  4004  and the lumen  4602  of the driver  4002 , including the proximal-most portion of the lumen that receives the first portion  4303  of the protrusion  4202  and a more distal portion of the lumen that receives the second portion  4308 . Coupling the two components in this manner can allow improved alignment therebetween as well as the transmission of torque between the components (e.g., they can be locked against relative rotation with respect to one another). 
     The instruments disclosed herein can be constructed from any of a variety of known materials. Example materials include those which are suitable for use in surgical applications, including metals such as stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and so forth. Further, various methods of manufacturing can be utilized, including 3D printing or other additive manufacturing techniques, as well as more conventional manufacturing techniques, including molding, stamping, casting, machining, etc. 
     The instruments and methods disclosed herein can be used in minimally-invasive surgery and/or open surgery. While the instruments and methods disclosed herein are generally described in the context of surgery on a human patient, it will be appreciated that the methods and instruments disclosed herein can be used in any of a variety of surgical procedures with any human or animal subject, or in non-surgical procedures. 
     The devices 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 device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. 
     Various devices or components described herein can be processed before use in a surgical procedure. For example, a new or used device or component can be obtained and, if necessary, cleaned. The device or component can be sterilized. In one sterilization technique, the device or component can be placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and its contents can be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation can kill bacteria on the device or component and in the container. The sterilized device or component can be stored in the sterile container. The sealed container can keep the device or component sterile until it is opened in the medical facility. Other forms of sterilization are also possible, including beta or other forms of radiation, ethylene oxide, steam, or a liquid bath (e.g., cold soak). Certain forms of sterilization may be better suited to use with different devices or components, or portions thereof, due to the materials utilized, the presence of electrical components, etc. 
     In this disclosure, phrases such as “at least one of” or “one or more of” may occur followed by a conjunctive list of elements or features. The term “and/or” may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B,” “one or more of A and B,” and “A and/or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, and/or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, B and C together, or A and B and C together.” In addition, use of the term “based on,” is intended to mean, “based at least in part on,” such that an un-recited feature or element is also permissible. 
     Further features and advantages based on the above-described embodiments are possible and within the scope of the present disclosure. Accordingly, the disclosure is not to be limited by what has been particularly shown and described. All publications and references cited herein are incorporated by reference in their entirety, except for any definitions, subject matter disclaimers or disavowals, and except to the extent that the incorporated material is inconsistent with the express disclosure herein, in which case the language in this disclosure controls. 
     Examples of the above-described embodiments can include the following: 
     1. A surgical assembly, comprising:
         a driver having a distal tip configured to couple with another component in a manner that prevents rotation therebetween, and a proximal driver body with a lumen extending from the proximal-most end of the driver to the distal-most end of the driver;   a driver adapter having a distal adapter body and a proximal torque-receiving end;   wherein the driver adapter is coupled to the driver such that a portion of the proximal driver body is received within a distal-facing cavity of the distal adapter body;   wherein the driver adapter is configured to impart rotational force to the driver and the distal adapter body includes a lock configured to prevent axial separation of the driver and the driver adapter.       

     2. The assembly of claim  1 , wherein the driver adapter includes a lumen extending from a proximal-most end of the driver adapter to the distal-facing cavity. 
     3. The assembly of any of claims  1  to  2 , wherein the lock includes one or more pivoting latches that interface with a groove formed on the driver. 
     4. The assembly of any of claims  1  to  3 , wherein the driver includes one or more flats formed on the proximal driver body that interface with one or more flats formed on an interior surface of the distal-facing cavity of the driver adapter. 
     5. The assembly of any of claims  1  to  4 , further comprising a retaining sleeve disposed over a portion of the driver. 
     6. The assembly of claim  5 , wherein the retaining sleeve includes a threaded distal end configured to interface with a bone screw receiver head. 
     7. The assembly of any of claims  5  to  6 , wherein the retaining sleeve includes a lock configured to prevent separation of the retaining sleeve and driver. 
     8. The assembly of any of claims  5  to  7 , further comprising a second sleeve disposed over a portion of the retaining sleeve. 
     9. The assembly of claim  8 , wherein the second sleeve includes a plurality of rigid extensions formed at a distal end thereof configured to be received between portions of a bone screw receiver head. 
     10. The assembly of any of claims  8  to  9 , wherein the second sleeve includes a plurality of flexible extensions formed at a proximal end thereof configured to deflect and ride over one or more surface features formed on the retaining sleeve. 
     11. The assembly of any of claims  8  to  10 , wherein the second sleeve is configured to move between a distal position, in which the second sleeve is locked against rotation relative to a bone screw receiver head coupled to the retaining sleeve, and a proximal position, in which the second sleeve can rotate relative to the bone screw receiver head coupled to the retaining sleeve. 
     12. The assembly of any of claims  1  to  11 , further comprising a driver handle coupled to the proximal torque-receiving end of the driver adapter. 
     13. The assembly of any of claims  1  to  12 , further comprising a surgical navigation array coupled to the driver adapter. 
     14. A surgical method, comprising:
         inserting a driver through a lumen of a retaining sleeve such that a tip formed at a distal-most end of the driver interfaces with a drive feature formed on a shank of a bone screw assembly;   coupling the retaining sleeve to a receiver head of the bone screw assembly;   coupling a driver adapter to the driver such that a proximal portion of the driver is received within a distal-facing cavity of the driver adapter and the driver adapter is locked against axial separation from the driver; and   rotating the driver adapter to impart corresponding rotation of the driver and the shank of the bone screw assembly.       

     15. The method of claim  14 , wherein rotation of the driver and the shank of the bone screw assembly is relative to the retaining sleeve. 
     16. The method of any of claims  14  to  15 , further comprising coupling a driver handle to a proximal end of the driver adapter. 
     17. The method of any of claims  14  to  16 , further comprising locking the driver against axial separation from the retaining sleeve. 
     18. The method of any of claims  14  to  17 , further comprising inserting the retaining sleeve through a lumen of a second sleeve. 
     19. The method of claim  18 , wherein inserting the retaining sleeve through the lumen of the second sleeve is performed before coupling the retaining sleeve to the receiver head of the bone screw assembly. 
     20. The method of any of claims  18  to  19 , further comprising moving the second sleeve between a distal position, in which the second sleeve is locked against rotation relative to the receiver head of the bone screw assembly, and a proximal position, in which the second sleeve can rotate relative to the receiver head of the bone screw assembly. 
     21. The method of any of claims  14  to  20 , wherein the steps of coupling the retaining sleeve to the receiver head, inserting the driver through the lumen of the retaining sleeve, and coupling the driver adapter to the driver are performed outside of a surgical field. 
     22. The method of any of claims  14  to  21 , further comprising:
         separating the driver adapter from the driver;   coupling a bone cement delivery device to the driver; and   delivering bone cement through the driver and the shank of the bone screw assembly.       

     23. A bone screw driver, comprising:
         a distal tip;   a proximal body;   wherein a lumen extends from the proximal-most end of the bone screw driver to the distal-most end of the bone screw driver;   wherein the tip is formed at a distal-most end of the bone screw driver and is configured to interface with a bone screw to impart torque thereto;   wherein the proximal body includes opposed flats formed thereon configured to allow application of torque to the bone screw driver;   wherein the proximal body has a diameter greater than a distance between the opposed flats at a position distal to the opposed flats.       

     24. The device of claim  23 , further comprising a coupling feature formed at a location proximal to the opposed flats, wherein the coupling feature is configured interface with a driver adapter in a manner that prevents axial separation of the bone screw driver and driver adapter. 
     25. The device of claim  24 , wherein the coupling feature includes a groove formed around a circumference of the proximal body. 
     26. The device of any of claims  23  to  25 , further comprising an intermediate portion extending between the distal tip and the proximal body portion, wherein the intermediate portion has a diameter less than a diameter of the proximal body portion. 
     27. The device of claim  26 , further comprising a first shoulder formed along the intermediate portion and a second shoulder formed along the intermediate portion at a position distal to the first shoulder. 
     28. The device of claim  27 , wherein the second shoulder includes a tapered distal-facing surface. 
     29. The device of any of claims  26  to  28 , wherein the distal tip has a diameter less than that of the intermediate portion. 
     30. The device of any of claims  23  to  29 , wherein the lumen includes at least one portion along its length with a tapering diameter. 
     31. The device of any of claims  23  to  30 , wherein a proximal-most portion of the proximal body has a conical outer surface with a diameter that tapers toward the proximal-most end of the driver. 
     32. A bone screw driver adapter, comprising:
         a distal adapter body;   a proximal torque-receiving end;   wherein the distal adapter body has a diameter greater than the proximal torque-receiving end;   wherein the distal adapter body defines a distal-facing cavity configured to receive a proximal portion of a bone screw driver;   wherein a distal-facing surface within the cavity includes a protrusion extending distally therefrom that is configured to be received within a lumen of the bone screw driver and impart torque thereto; and   wherein the distal adapter body includes a lock configured to engage with the proximal portion of the bone screw driver when received within the cavity to prevent axial separation of the bone screw driver and the bone screw driver adapter.       

     33. The device of claim  32 , wherein the proximal torque-receiving end includes one or more flats configured to allow application of torque to the bone screw driver adapter. 
     34. The device of any of claims  32  to  33 , further comprising an intermediate portion extending between the distal adapter body and the proximal torque-receiving end, wherein the intermediate portion has a diameter less than a diameter of the distal adapter body. 
     35. The device of any of claims  32  to  34 , wherein the bone screw driver adapter includes a lumen extending from a proximal-most end of the adapter to the distal-facing cavity. 
     36. The device of any of claims  32  to  35 , wherein the lock includes one or more pivoting latches with a first end exposed along an outer surface of the distal adapter body and a second end extending into the distal-facing cavity. 
     37. The device of claim  36 , wherein the one or more pivoting latches are biased to drive the second end radially inward within the distal-facing cavity. 
     38. The device of any of claims  32  to  37 , further comprising a surgical navigation array mount disposed between the distal adapter body and the proximal torque-receiving end. 
     39. The device of any of claims  32  to  38 , wherein the distal-facing cavity includes at least one opening formed therein that extends to an outer surface of the adapter body. 
     40. The device of any of claims  32  to  39 , wherein the outer surface of the distal adapter body includes one or more flats formed thereon. 
     41. The device of any of claims  32  to  40 , wherein the protrusion includes one or more flats formed thereon. 
     42. The device of claim  41 , wherein the protrusion includes a first portion having the one or more flats formed thereon and a second portion extending distal to the first portion and having a diameter less than a diameter of the first portion. 
     43. A bone screw driver, comprising:
         a distal tip;   a proximal body;   wherein a lumen extends from the proximal-most end of the bone screw driver to the distal-most end of the bone screw driver;   wherein the tip is formed at a distal-most end of the bone screw driver and is configured to interface with a bone screw to impart torque thereto;   wherein a proximal-most portion of the lumen includes one or more flat sidewall portions configured to allow application of torque to the bone screw driver.       

     44. The device of claim  43 , wherein a diameter of the lumen is greatest along the proximal-most portion having the one or more flat sidewall portions.