Patent Publication Number: US-2022211391-A1

Title: Surgical Handpiece System for Depth Measurement and Related Accessories

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The subject patent application is a U.S. Continuation patent application of U.S. Ser. No. 16/639,690 filed on Feb. 17, 2020, which claims priority to international Patent Application No, PCT/IB2018/056251, filed on Aug. 17, 2018, which is a continuation-in-part patent application of U.S. patent application Ser. No. 15/887,507 filed on Feb. 2, 2018; now U.S. Pat. No. 10,159,495 issued Dec. 25, 2018, which claims priority to and all the benefits of U.S. Provisional Patent Application No. 62/618,134 filed on Jan. 17, 2018, U.S. Provisional Patent Application No. 62/548,357 filed on Aug. 21, 2017, and U.S. Provisional Patent Application No. 62/546,760 filed on Aug. 17, 2017, the disclosures of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates, generally, to a surgical handpiece and related accessories for measuring depth of bore holes. 
     BACKGROUND 
     Conventional medical and surgical procedures routinely involve the use of surgical tools and instruments which allow surgeons to approach and manipulate surgical sites. By way of non-limiting example, rotary instruments such as handheld drills are commonly utilized in connection with orthopedic procedures to address various musculoskeletal conditions, such as trauma, sports injuries, degenerative diseases, joint reconstruction, and the like. In procedures where handheld drills or similar surgical instruments are employed, rotational torque selectively generated by an actuator (e.g., an electric motor) is used to rotate a releasably-attachable drill bit or other surgical attachments at different speeds. Drill bits utilized in connection with medical and surgical procedures are typically realized as single-use components that are replaced between procedures. 
     While handheld surgical instruments and drill bits are routinely utilized to assist in the performance of a variety of different types of medical and/or surgical procedures, there is a need in the art to continuously improve such drill bits and handheld surgical instruments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is perspective view of a surgical handpiece system comprising a surgical handpiece assembly and a measurement module, the surgical handpiece assembly shown having a drill bit and a tip protector according to one configuration. 
         FIG. 2  is a partially-exploded perspective view of the surgical handpiece system of  FIG. 1 , with the surgical handpiece system shown having a measurement module, a drive cannula, and a release assembly spaced from a handpiece housing assembly, and with the end effector assembly removed from the surgical handpiece assembly and shown with the tip protector spaced from a distal cutting tip portion of the drill bit. 
         FIG. 3  is a partially-exploded perspective view of portions of the surgical handpiece assembly of  FIGS. 1-2 , shown with the drive cannula and the release assembly spaced from a phantom outline of the handpiece housing assembly to depict an actuator assembly. 
         FIG. 4  is a partial isometric sectional view taken along line  4 - 4  in  FIG. 1 . 
         FIG. 5  is an enlarged detail view taken at indicia  5  in  FIG. 4 . 
         FIG. 6  is a sectional view taken longitudinally through the surgical handpiece assembly of  FIGS. 1-5 , with the end effector assembly removed from the surgical handpiece assembly. 
         FIG. 7A  is an enlarged detail view taken at indicia  7  in  FIG. 6 , shown depicting portions of the measurement module, the drive cannula, the release assembly, and the actuator assembly within the handpiece housing assembly. 
         FIG. 7B  is another enlarged detail view of the surgical handpiece system of  FIGS. 1 and 7A , shown with a pair of resilient arms arranged at a proximal end of the drill bit approaching a proximal portion of the drive cannula. 
         FIG. 7C  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7B , shown with the resilient arms of the drill bit engaging against a seat surface of the proximal portion of the drive cannula and deflecting towards each other. 
         FIG. 7D  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7C , shown with the resilient arms of the drill bit disposed within a bore of the proximal portion of the drive cannula, the drill bit shown having a shank with a proximal end from which the resilient arms extend, a stop coupled to the shank, and an interface coupled to the shank and interposed between the stop and the proximal end. 
         FIG. 7E  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7D , shown with the resilient arms of the drill bit disposed further within the bore of the proximal portion of the drive cannula, and with the interface of the drill bit positioned within the bore of the proximal portion of the drive cannula adjacent to the seat surface. 
         FIG. 7F  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7E , shown with the resilient arms of the drill bit deflected resiliently away from one another with each resilient arm having a retention surface abutting a lock surface of the proximal portion of the drive cannula, and shown with the stop of the drill bit abutting the seat surface of the proximal portion of the drive cannula to retain the interface within the bore. 
         FIG. 7G  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7F , shown with a release member of the release assembly engaging against the resilient arms and deflecting the resilient arms toward one another to facilitate moving the retention surfaces of the resilient arms out of abutment with the lock surfaces of the proximal portion of the drive cannula. 
         FIG. 7H  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7G , shown with the release member of the release assembly further engaging against and deflecting the resilient arms with the retention surfaces out of abutment with the lock surfaces of the proximal portion of the drive cannula. 
         FIG. 7I  is another enlarged detail view of the surgical handpiece system of  FIGS. 7A-7H , shown with the release member of the release assembly out of engagement with the resilient arms, and shown with the resilient arms disposed within the bore of the proximal portion of the drive cannula adjacent to and out of contact with the lock surfaces. 
         FIG. 8  is an exploded perspective view of the drive cannula of  FIGS. 2-7I . 
         FIG. 9  is a partially-exploded view of the actuator assembly of  FIGS. 3-7I , shown having a motor with a drive gear, and a gearset with an output hub. 
         FIG. 10  is an exploded perspective view of the gearset of  FIG. 9 . 
         FIG. 11  is another exploded perspective view of the gearset of  FIGS. 9-10 . 
         FIG. 12  is a partially-exploded view of the release assembly of  FIGS. 1-7I , shown having a release subassembly spaced from a keeper body and a housing adapter. 
         FIG. 13  is an exploded perspective view of the release subassembly of  FIG. 12 . 
         FIG. 14  is another exploded perspective view of the release subassembly of  FIGS. 12-13 . 
         FIG. 15A  is a perspective view showing the proximal portion of the drive cannula depicted in  FIGS. 2-8  positioned adjacent to the output hub of the gearset depicted in  FIGS. 3-7I and 9-11 . 
         FIG. 15B  is a perspective view of the proximal portion of the drive cannula and the output hub of  FIG. 15A  assembled for concurrent rotation via splined engagement, shown positioned adjacent to the resilient arms extending from the proximal end of the shank of the drill bit of  FIGS. 1-2, 4-5, and 7B-7I . 
         FIG. 15C  is another perspective view of the proximal portion drive cannula, the output hub, and the drill bit of  FIG. 15B , shown with the resilient arms of the drill bit disposed in abutment with the lock surfaces of the proximal portion of the drive cannula. 
         FIG. 15D  is a perspective view of another proximal portion of a drive cannula positioned adjacent to another output hub. 
         FIG. 16  is a top-side view of the proximal portion of the drive cannula and the output hub assembled as depicted in  FIG. 15B . 
         FIG. 17A  is a sectional view taken along line  17 - 17  in  FIG. 16 , depicting the proximal portion of the drive cannula disposed within the output hub as illustrated in  FIG. 15B . 
         FIG. 17B  is another sectional view of the proximal portion of the drive cannula and the output hub of  FIG. 17A , shown with the resilient arms of the drill bit of  FIGS. 1-2, 4-5, 7B-7I, and 15B-15C  disposed within the bore of the proximal portion of the drive cannula. 
         FIG. 17C  is another sectional view of the proximal portion of the drive cannula, the output hub, and the drill bit of  FIG. 17B , shown with the resilient arms of the drill bit disposed in abutment with the lock surfaces of the proximal portion of the drive cannula as illustrated in  FIG. 15C . 
         FIG. 18A  is a sectional view taken along line  18 - 18  in  FIG. 16 , depicting the profile of the bore of the proximal portion of the drive cannula. 
         FIG. 18B  is another sectional view of the proximal portion of the drive cannula of  FIG. 18A , shown with the resilient arms of the drill bit of  FIGS. 1-2, 4-5, 7B-7I , and  15 B- 15 C disposed within and abutting against the bore of the proximal portion of the drive cannula, the drill bit being arranged as illustrated in  FIG. 17B . 
         FIG. 18C  is another sectional view of the proximal portion of the drive cannula and the drill bit of  FIG. 18B , shown with the interface disposed within the bore of the proximal portion of the drive cannula. 
         FIG. 19A  is a sectional view taken along line  19 - 19  in  FIG. 16 , depicting splined engagement between the proximal portion of the drive cannula and the output hub adjacent to the lock surfaces of the proximal portion of the drive cannula. 
         FIG. 19B  is another sectional view of the proximal portion of the drive cannula and the output hub. 
         FIG. 19C  is another sectional view of the proximal portion of the drive cannula and the output hub of  FIGS. 19A-19B , shown with portions of the resilient arms of the drill bit disposed within and abutting against the bore of the proximal portion of the drive cannula, the drill bit being arranged as illustrated in  FIG. 17C . 
         FIG. 20  is a partial perspective view of the drill bit of  FIGS. 1-2, 4-5, 7B-7I, 15B-15C, 17B-17C, and 19B-19C  showing additional detail of the resilient arms, the interface, and the stop adjacent to the proximal end of the shank. 
         FIG. 21  is another partial perspective view of the portions of the drill bit illustrated in  FIG. 20 . 
         FIG. 22  is a left-side view of the portions of the drill bit illustrated in  FIGS. 20-21 . 
         FIG. 23  is a top-side view of the portions of the drill bit illustrated in  FIGS. 20-22 . 
         FIG. 24A  is a partial perspective view of the drill bit of  FIGS. 1-2, 4-5, 7B-7I, and 15B-15C  and the proximal portion of the drive cannula of  FIGS. 15A-15B , shown with the interface of the drill bit misaligned with the bore of the proximal portion of the drive cannula. 
         FIG. 24B  is another partial perspective view of the drill bit and the proximal portion of the drive cannula of  FIG. 24A , shown with the interface of the drill bit subsequently aligned with the bore of the proximal portion of the drive cannula. 
         FIG. 25  is a partial perspective view of another drill bit configuration, shown having a single resilient arm. 
         FIG. 26  is another partial perspective view of the configuration of the drill bit illustrated in  FIG. 25 . 
         FIG. 27  is a partial perspective view of another drill bit configuration, shown having three resilient arms. 
         FIG. 28  is a partial longitudinal sectional view of the configuration of the drill bit illustrated in  FIG. 27 , shown having a cannulated shank. 
         FIG. 29  is a front-side schematic view representing the proximal portion of the drive cannula, the output hub, and the drill bit arranged as depicted in  FIG. 15C , the schematic view showing the arrangement of the lock surfaces of the proximal portion of the drive cannula delineated from one another by the splined engagement between the proximal portion of the drive cannula and the output hub, the schematic view further showing the profile of the interface of the drill bit with dash-dash lines disposed within the bore of the proximal portion of the drive cannula, and the schematic view still further showing the arrangement of the resilient arms with dash-dot-dash lines to illustrate abutment with the lock surfaces of the proximal portion of the drive cannula as well as radial alignment of the retention surfaces of the resilient arms with respect to the profile of the interface. 
         FIG. 30  is another front-side schematic view representing the proximal portion of the drive cannula and the output hub of  FIG. 29  with a configuration of a drill bit having resilient arms shown sized, shaped, and arranged in abutment with the lock surfaces of the proximal portion of the drive cannula. 
         FIG. 31  is another front-side schematic view representing the proximal portion of the drive cannula and the output hub of  FIGS. 29-30  with a configuration of a drill bit having an interface shown with a generally rectangular profile. 
         FIG. 32  is another front-side schematic view representing the proximal portion of the drive cannula and the output hub of  FIGS. 29-31  with a configuration of a drill bit having an interface shown with a generally star-shaped profile. 
         FIG. 33  is another front-side schematic view representing the proximal portion of the drive cannula and the output hub of  FIGS. 29-32  with a configuration of a drill bit having an interface shown with an irregularly-shaped profile. 
         FIG. 34  is a partial perspective view of the end effector assembly of  FIGS. 1-2 , shown with the distal cutting tip portion of the drill bit disposed within the tip protector. 
         FIG. 35  is a perspective view of the tip protector of the end effector assembly illustrated in  FIGS. 1-2 and 34 . 
         FIG. 36  is a sectional view taken along line  36 - 36  in  FIG. 35 . 
         FIG. 37  is a perspective view of another tip protector configuration of the end effector assembly. 
         FIG. 38  is a sectional view taken along line  38 - 38  in  FIG. 37 . 
         FIG. 39  is a perspective view of another tip protector configuration of the end effector assembly. 
         FIG. 40  is a sectional view taken along line  40 - 40  in  FIG. 39 . 
         FIG. 41  is a perspective view of another tip protector configuration of the end effector assembly. 
         FIG. 42  is a sectional view taken along line  42 - 42  in  FIG. 41 . 
         FIG. 43  is a perspective view of another tip protector configuration of the end effector assembly. 
         FIG. 44  is a sectional view taken along line  44 - 44  in  FIG. 43 . 
         FIG. 45  is a perspective view of another tip protector configuration of the end effector assembly. 
         FIG. 46  is a sectional view taken along line  46 - 46  in  FIG. 45 . 
         FIG. 47  is a perspective view of a surgical attachment module adjacent a surgical handpiece assembly. 
         FIG. 48  is another perspective view of the surgical attachment module adjacent the surgical handpiece assembly of  FIG. 47 . 
         FIG. 49  is a partial isometric sectional view of the surgical attachment module coupled to the surgical handpiece assembly of  FIGS. 47-48  taken generally along a longitudinal axis. 
         FIG. 50  is a partial isometric sectional view of the surgical handpiece assembly of  FIGS. 47-49  taken generally transverse to the longitudinal axis. 
         FIG. 51  is a partial isometric sectional view of the surgical attachment module coupled to the surgical handpiece assembly of  FIGS. 47-50  taken generally transverse to the longitudinal axis. 
         FIG. 52  is a perspective view of a measurement module adjacent a surgical handpiece assembly. 
         FIG. 53  is another perspective view of the measurement module adjacent the surgical handpiece assembly of  FIG. 52 . 
         FIG. 54  is a partial isometric sectional view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 52-53  taken generally along a longitudinal axis. 
         FIG. 55  is a perspective view of another measurement module adjacent a surgical handpiece assembly. 
         FIG. 56  is another perspective view of the measurement module adjacent the surgical handpiece assembly of  FIG. 55 . 
         FIG. 57  is a partial isometric sectional view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 55-56  taken generally along a longitudinal axis. 
         FIG. 58  is an enlarged detail view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 55-57 , taken at indicia  58  in  FIG. 57 . 
         FIG. 59  is another enlarged detail view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 55-58 , taken at indicia  59  in  FIG. 57 . 
         FIG. 60  is a partial isometric sectional view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 55-59  taken generally transverse to the longitudinal axis. 
         FIG. 61  is a sectional view of the measurement module coupled to the surgical handpiece assembly of  FIGS. 55-60  taken generally along the longitudinal axis and transverse to the view of  FIG. 57 . 
         FIG. 62  is a partially-exploded view of the measurement module of  FIGS. 55-61  showing a biasing mechanism disposed in an interior of a measurement housing. 
         FIG. 63  is an enlarged view of the measurement module of  FIGS. 55-62  showing the biasing mechanism disposed in the interior of the measurement housing. 
         FIG. 64  is a perspective view of the measurement module of  FIGS. 55-63 . 
         FIG. 65  is a perspective view of the measurement module of  FIGS. 55-64  showing a bushing and showing the measurement housing and a depth cannula in phantom. 
         FIG. 66  is a perspective view of the measurement module of  FIGS. 55-64  showing protrusions extending from distal portion of the bushing into a bore of the bushing. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to the drawings, where like numerals are used to designate like structure throughout the several views, a surgical handpiece system is shown at  60  in  FIGS. 1-2  for performing an operational function associated with medical and/or surgical procedures. In the representative configuration illustrated herein, the surgical handpiece system  60  is employed to facilitate penetrating tissue of a patient, such as bone. To this end, the illustrated configuration of the surgical handpiece system  60  comprises a surgical handpiece assembly  62  and an end effector assembly, generally indicated at  64 . The end effector assembly  64 , in turn, comprises a drill bit  66  and a tip protector  68 . As is best depicted in  FIG. 2 , the drill bit  66  extends generally longitudinally along an axis AX between a cutting tip portion, generally indicated at  70 , and an insertion portion, generally indicated at  72 . As is described in greater detail below, the cutting tip portion  70  is configured to engage tissue, and the insertion portion  72  is configured to facilitate releasable attachment of the drill bit  66  to the surgical handpiece assembly  62 . 
     In order to help facilitate attachment of the drill bit  66  to the surgical handpiece assembly  62 , in some configurations, the tip protector  68  is configured to releasably secure to the cutting tip portion  70  of the drill bit  66  while concealing at least a portion of the cutting tip portion  70  of the drill bit  66 , thereby allowing a user (e.g., a surgeon) of the surgical handpiece system  60  to handle and position the drill bit  66  safely during attachment to the surgical handpiece assembly  62 . Once the end effector assembly  64  has been attached to the surgical handpiece assembly  62 , the tip protector  68  is subsequently removed from the cutting tip portion  70  of the drill bit  66 , and the surgical handpiece system  60  can then be utilized to penetrate tissue. Configurations of the tip protector  68  are described in greater detail below in connection with  FIGS. 34-46 . 
     While drill bits are described about, it should be appreciated that the coupling geometry described throughout with respect to the drill bit may be used in conjunction with any other type of surgical end effector, especially rotary surgical end effectors, such as a cannulated drill bit, a rongeur, etc. 
     Referring now to  FIGS. 1-19C , in the representative configuration illustrated herein, the surgical handpiece assembly  62  is realized as a handheld drill with a pistol-grip shaped handpiece housing assembly  74  which releasably attaches to a battery  76  (battery attachment not shown in detail). However, it is contemplated that the handpiece housing assembly can have any suitable shape with or without a pistol grip. While the illustrated surgical handpiece assembly  62  employs a battery  76  which is releasably attachable to the handpiece housing assembly  74  to provide power to the surgical handpiece assembly  62  utilized to rotate the drill bit  66 , it will be appreciated that the surgical handpiece assembly  62  may be configured in other ways, such as with an internal (e.g., non-removable) battery, or with a tethered connection to an external console, power supply, and the like. Other configurations are contemplated. 
     The handpiece housing assembly  74  has a proximal region adjacent the release assembly  150  (described in greater detail further below) and a distal region opposite the proximal region. Unless otherwise specified “Proximal” is understood to mean toward a user holding the handpiece housing assembly. “Distal” is understood to mean away from the user holding the handpiece housing assembly. 
     In the illustrated configuration, the battery  76  or other power source provides power to a controller  78  (depicted schematically in  FIG. 6 ) which, in turn, is disposed in communication with a user input device  80  and an actuator assembly  82  (see also  FIG. 3 ). The user input device  80  and the actuator assembly  82  are each supported by the handpiece housing assembly  74 . The controller  78  is generally configured to facilitate operation of the actuator assembly  82  in response to actuation of the user input device  80 . The user input device  80  has a trigger-style configuration in the illustrated configuration, is responsive to actuation by a user (e.g., a surgeon), and communicates with the controller  78 , such as via electrical signals produced by magnets and Hall effect sensors. Thus, when the surgeon actuates the user input device  80  to operate the surgical handpiece assembly  62 , the controller  78  directs power from the battery  76  to the actuator assembly  82  which, in turn, generates rotational torque employed to rotate the drill bit  66  or other surgical end effector, as described in greater detail below. Those having ordinary skill in the art will appreciate that the handpiece housing assembly  74 , the battery  76 , the controller  78 , and the user input device  80  could each be configured in a number of different ways to facilitate generating rotational torque without departing from the scope of the present disclosure. 
     As is best shown in  FIG. 9 , the actuator assembly  82  generally comprises an electric motor  84  and a gearset  86  which are each supported within the handpiece housing assembly  74 . The motor  84  is configured to selectively generate rotational torque in response to commands, signals, and the like received from the controller  78 . As is best shown in  FIG. 6 , the motor  84  comprises a rotor cannula  88  supported for rotation about the axis AX by a pair of bearings  90 . A drive gear  92  arranged adjacent to the gearset  86  (see  FIG. 9 ) is coupled to and rotates concurrently with the rotor cannula  88 , and is employed to transmit rotational torque to the gearset  86 . To this end, in the illustrated configuration, and as is shown in  FIGS. 10-11 , the gearset  86  is realized as two-stage compound planetary arrangement and generally comprises a ring gear housing  94  which, among other things, rotationally supports an output hub  96  via a bearing  90 , as well as one or more retaining clips  98 , washers  100 , and/or seals  102 . The ring gear housing  94  is coupled to a motor housing  85  of the motor  84 . However, other configurations of the gearset  86  are contemplated. For example, the motor and/gear set shown in International Patent Publ. No. WO 2007/002230 entitled “Surgical Handpiece with Compact Clutch and Anti-Wobble Coupling Head” and filed on Jun. 20, 2006, is hereby incorporated by reference in its entirety, may be used for the surgical handpiece assembly. 
     With continued reference to  FIGS. 10-11 , in the illustrated configuration, the output hub  96  of the gearset  86  comprises an integrated carrier  104  to which three planet gears  106  are supported via an arrangement of shafts  108  and, in some configurations, bushings  110  interposed between the shafts  108  and the planet gears  106 . The planet gears  106  are disposed in meshed engagement with the ring gear housing  94  and also with a sun gear  112 . The sun gear  112  rotates concurrently with a second carrier  104  which, in turn, supports an additional three planet gears  106  via respective shafts  108  and bushings  110 . These additional planet gears  106  are likewise disposed in meshed engagement with the ring gear housing  94 , and are disposed in meshed engagement with the drive gear  92  of the motor  84 . Thus, rotation of the drive gear  92  via actuation of the motor  84  effects concurrent rotation of the output hub  96 . As is described in greater detail below in connection with  FIGS. 15A-15C and 17A-19C , the output hub  96  rotates concurrently with the drill bit  66 . Those having ordinary skill in the art will appreciate that the actuator assembly  82  could be configured in other ways without departing from the scope of the present disclosure. By way of non-limiting example, while the illustrated actuator assembly  82  employs a compound planetary arrangement to adjust rotational speed and torque between the drive gear  92  of the motor  84  and the output hub  96 , other types of gearsets  86  could be utilized in some configurations. Moreover, while the illustrated actuator assembly  82  employs an electrically-powered brushless DC motor to generate rotational torque, other types of prime movers could be utilized. Other configurations are contemplated. 
     As noted above, rotational torque generated by the motor  84  effects rotation of the output hub  96  which, in turn, rotates concurrently with the drill bit  66 . To this end, and as is best shown in  FIGS. 2-5 and 8 , the surgical handpiece assembly  62  further comprises a drive cannula  114  which generally extends through the various cannulated components of the actuator assembly  82  into splined engagement with the output hub  96  of the gearset  86 . As is described in greater detail below, the drive cannula  114  is configured to facilitate releasable attachment between the drill bit  66  and the surgical handpiece assembly  62 . The drive cannula  114  generally comprises a proximal portion  116 , a distal portion  118 , and a body portion  120 . The proximal portion  116 , distal portion  118 , and the body portion  120  of the drive cannula  114  are supported for rotation about the axis AX concurrently. In some configurations, the portions  116 ,  118 ,  120  of the drive cannula  114  are integrally formed. In other configurations, the portions  116 ,  118 ,  120  of the drive cannula  114  may be formed separately from and subsequently attached to each other via welding, brazing, adhering, bonding, or any suitable process sufficient to operatively attach the portions  116 ,  118 ,  120  of the drive cannula  114  together. In some Figures shown herein, the body portion  120  and the distal portion  118  are removed to best illustrate the relationship of the proximal portion  116  of the drive cannula  114  to other components of the surgical handpiece assembly  62 . It is appreciated that the body portion  120  and the distal portion  118  are coupled to the proximal portion  116  of the drive cannula  114  as illustrated in  FIG. 2 . Furthermore, it should be appreciated that the drive cannula may take other forms other than described above, and may simply be a drive element that transfers torque without including a lumen. 
     The drive cannula  114  is supported for rotation about the axis AX within the handpiece housing assembly  74  via splined engagement with the output hub  96  adjacent the proximal portion  116  of the drive cannula  114 , and via an arrangement of bearings  90 , snap rings  100 , and seals  102  adjacent the distal portion  118  of the drive cannula  114  (see  FIGS. 6 and 8 ). As is described in greater detail below in connection with  FIGS. 15A-33 , the proximal portion  116  of the drive cannula  114  comprises a generally hexagonal bore  122  which is employed to receive an interface  124  of the drill bit  66  (see  FIG. 2 ) so as to facilitate concurrent rotation between the drill bit  66  and the drive cannula  114 . As will be appreciated from the subsequent description below, the interface  124  is defined by physical structure extending outwardly from the axis AX such that the interface  124  is configured to be driven externally. As is best shown in  FIG. 8 , the body portion  120  of the drive cannula  114  and the distal portion  118  of the drive cannula  114  each have cylindrical bores. However, other configurations of the body portion  120  of the drive cannula  114  and the distal portion  118  of the drive cannula  114  can have non-cylindrical bores, such as polygonal or oval bore profiles. Other configurations of the bearings, snap-rings and seals are also contemplated. Similarly, the engagement of the output member to the drive cannula/drive element may take any suitable form so long as torque gets transferred from the motor to the drive cannula/drive element. 
     As noted above, the proximal portion  116  of the drive cannula  114  is configured to engage the drill bit  66  to rotate the drill bit  66  about the axis AX. The internal surface defining the bore  122  of the proximal portion  116  of the drive cannula  114  comprises a first driving portion for transmitting torque to the drill bit  66 . As will be described in greater detail below the distal portion  118  of the drive cannula  114  comprises a distal protrusion, generally indicated at  126 , comprising a second driving portion which is provided to facilitate transmitting rotational torque when the surgical handpiece assembly  62  is utilized in connection with other applications besides rotating the drill bit  66 . In the illustrated configurations, as best shown in  FIGS. 2 and 8 , the distal protrusion  126  extends distally and generally parallel to the axis AX and defines the distal end of the drive cannula  114 . In other configurations, the distal protrusion  126  extends perpendicular to the axis AX. In still other configurations, the distal protrusion  126  extends at an oblique angle between perpendicular and parallel to the axis AX. In one configuration, the distal protrusion  126  operates as a drive dog/torque transmission geometry to transmit torque via interference coupling. More specifically, in the aforementioned configurations, the drive cannula  114  is configured such that the surgical handpiece assembly  62  can rotate, drive, or otherwise actuate a number of different types of surgical attachments, tools, modules, end effectors, and the like, which can be configured to engage and rotate concurrently with the distal protrusion  126  of the distal portion  118  of the drive cannula  114 . It will be appreciated that this allows the same surgical handpiece assembly  62  to be utilized in a broad number of medical and/or surgical procedures. Details relating to the distal portion  118  of the drive cannula  114  will be discussed further below. However, it is contemplated that the drive cannula  114  could be configured differently in some configurations, such as to omit a distal protrusion  126  at the distal portion  118  of the drive cannula  114  in configurations where the surgical handpiece assembly  62  is configured for dedicated use with the drill bit  66  of the present disclosure. 
     Referring now to  FIGS. 1-2, 4, and 6 , the illustrated configuration of the surgical handpiece system  60  further comprises a measurement module, generally indicated at  128 , which is configured to releasably attach to the surgical handpiece assembly  62  to provide the surgeon with measurement functionality during use. To this end, and as is shown in  FIGS. 4 and 6 , the measurement module  128  generally comprises a housing  130 , a guide bushing  132 , a depth cannula  134 , a displacement sensor assembly  136 , a rotatable gear  146 . In some configurations, the housing  130  is releasably attachable to the surgical handpiece assembly  62 . In other configurations, the measurement module  128  is releasably attached to the handpiece housing assembly  74  in another manner. In certain configurations, the measurement module may include one or more buttons for controlling a function of the measurement module. Configurations for releasable attachment of the measurement module  128  to the handpiece housing assembly  74  are discussed in greater detail further below. The housing  130  generally supports the various components of the measurement module  128 . The housing  130  illustrated in  FIGS. 4 and 6  is formed as a pair of housing components  138  which interlock or otherwise attach together, and may be configured for disassembly to facilitate cleaning or servicing the measurement module  128 . In the illustrated configurations, the housing components  138  and the guide bushing  132  comprise correspondingly-shaped features arranged to prevent relative axial and rotational movement therebetween, such as via notches formed in the guide bushing  132  which fit into webs or ribs formed in the housing components  138  (not shown in detail). For example, the guide bushing  132  may include one or more wings  133  (see  FIGS. 63 and 65 ) to stabilize the measurement housing  138  and provide support for when buttons  135  (see  FIGS. 62 and 64 ) of the measurement module are depressed. The wings  133  of the guide bushing  132  may sit within one or more recesses of the measurement housing  138 . The guide bushing  132  further comprises a window  142  for use with the gear  146  as described in detail below. 
     The depth cannula  134  is disposed within the guide bushing  132  and is supported for translational movement along a measurement axis MX. When the measurement module  128  is attached to the surgical handpiece assembly, the measurement axis MX is arranged to be coaxial with the axis AX. An elongated recessed slot  143  (partially depicted in  FIG. 2 ) is optionally formed transversely into the depth cannula  134  and extends longitudinally. While not specifically illustrated herein, the elongated recessed slot  143  is shaped and arranged to receive a travel stop element which, in turn, is supported by the housing  130  and likewise extends through an aperture formed transversely through the side of the guide bushing  132 ; this arrangement serves both to limit how far the depth cannula  134  can be axially extended or retracted relative to the guide bushing  132 , and also prevents the depth cannula  134  from rotating about the measurement axis MX. However, it will be appreciated that the measurement module  128  could be configured to limit or prevent movement of the depth cannula  134  in other ways without departing from the scope of the present disclosure. 
     The depth cannula  134  further comprises a plurality of rack teeth  144  disposed linearly along at least a partial length of the depth cannula  134  which are disposed in meshed engagement with the gear  146  arranged adjacent a distal end of the guide bushing  132 . As shown in  FIG. 6 , the window  142  of the guide bushing  132  is arranged adjacent to the gear  146  to facilitate the meshed engagement between the rack teeth  144  and the gear  146  such that rotation of the gear  146  and movement of the depth cannula  134  are directly proportional. The displacement sensor assembly  136  is responsive to rotation of the gear  146  resulting from axial movement of the depth cannula  134 , and may be realized with a potentiometer, a rotary encoder, and the like, in order to generate electrical signals representing changes in the position of the depth cannula  134  along the measurement axis MX. Thus, it will be appreciated that the displacement sensor assembly  136  is able to provide the surgical handpiece system  60  with enhanced functionality. By way of example, in some configurations, the displacement sensor assembly  136  may be disposed in communication with the controller  78 , which may be configured to interrupt or adjust how the motor  84  is driven based on movement of the depth cannula  134 , such as to slow rotation of the drill bit  66  at a specific drilling depth into tissue. The displacement sensor assembly  136  may also be disposed in communication with a display  148 , such as a display screen, one or more light-emitting diodes (LEDs), and the like, to provide the surgeon with information relating to movement of the depth cannula  134 , such as to display a real-time drilling depth, a recorded historical maximum drilling depth, and the like. Other configurations are contemplated. This same information may also be communicated to the user with a speaker, so as to provide audio indications of the real-time drilling depth, a recorded historical maximum drilling depth, and the like. The disclosure of International Patent Publ. No. WO/2017/040783 entitled “Powered Surgical Drill With Integral Depth Gauge That Includes A Probe That Slides Over A Drill Bit” and filed on Sep. 1, 2016, is hereby incorporated by reference in its entirety. 
     Those having ordinary skill in the art will appreciate that the various components of the measurement module  128  could be arranged in a number of different ways. Moreover, while the illustrated measurement module  128  attaches to the illustrated surgical handpiece assembly  62  and is compatible with the drill bit  66  of the present disclosure, it is contemplated that the surgical handpiece assembly  62  could omit the measurement module  128  in some configurations, such as to employ different types of modules, housings, covers, and the like. 
     Referring now to  FIGS. 1-3 and 12-14 , the illustrated configuration of the surgical handpiece assembly  62  further comprises a release assembly, generally indicated at  150 , configured to facilitate removal of the drill bit  66  as described in greater detail below in connection with  FIGS. 7F-7I . As shown in  FIG. 12 , the release assembly  150  generally comprises a release subassembly  152 , a keeper body  154 , and a housing adapter  156 . The keeper body  154  and the housing adapter  156  are respectively configured to secure the release subassembly  152  to the actuator assembly  82  and the handpiece housing assembly  74 , and could be realized with a number of different configurations or could be integrated into other parts of the surgical handpiece assembly  62  in some configurations. As shown in  FIGS. 13-14 , the release subassembly  152  of the release assembly  150  comprises a release body  158 , a washer  100 , a pair of guide elements  160 , a collar  162 , a release member  164 , and a cap  166 . The guide elements  160  are supported within pockets  168  formed in the release member  164 , ride along respective helical slots  170  formed in the release body  158 , and move along respective collar channels  172  formed in the collar  162 . The guide elements  160  in the illustrated configuration are spherical. This arrangement allows the release member  164  to translate distally and proximally along the axis AX in response to rotation of the collar  162  (see  FIGS. 7F-7I ). As is described in greater detail below, the release member  164  comprises an actuating element  174  which defines a release surface  175  that is configured to engage the insertion portion  72  of the drill bit  66  in response to rotation of the collar  162 . Rotation of the collar  162  causes the release member  164  to translate distally along the axis AX, to facilitate removing the drill bit  66  from the drive cannula  114  of the surgical handpiece assembly  62 . In the illustrated configuration, the release surface  175  is an annular surface that tapers away from the axis AX proximally to distally. A biasing element such as a compression spring (not shown) may be interposed between the release body  158  and the release member  164 , along with one or more washers  100 , to urge the release member  164  toward the cap  166 . Other suitable biasing elements and/or fasteners could be employed to facilitate urging the release member  164  toward the cap and/or axially retaining the release member  164  relative to the release subassembly. 
     As noted above, the drill bit  66  of the present disclosure generally extends along the axis AX between the cutting tip portion  70  and the insertion portion  72 , and is configured for releasable attachment to the surgical handpiece assembly  62  described herein and illustrated throughout the drawings via engagement between the interface  124  of the drill bit  66  and the bore  122  of the proximal portion  116  of the drive cannula  114 . The drive cannula  114 , in turn, cooperates with the output hub  96  of the gearset  86  of the actuator assembly  82  to facilitate rotating the drill bit  66  about the axis AX. The drill bit  66 , the drive cannula  114 , and the output hub  96 , as well as the cooperation therebetween, will each be described in greater detail below. 
     Referring now to  FIGS. 2 and 20-24B , the drill bit  66  comprises a shank, generally indicated at  176 , which extends along the axis AX between a proximal end  178  and a distal end  180  (shown in  FIG. 2 ). The distal end  180  of the shank  176  is provided with flutes  182  which are helically disposed about the axis AX and extend to the tip of the drill bit  66  to promote tissue penetration (see  FIG. 2 ). In the illustrated configuration, the drill bit  66  is also optionally provided with a bearing region  184  coupled to the shank  176  between the proximal end  178  and the distal end  180  (see  FIG. 2 ). The bearing region  184  is sized so as to be received within and rotate relative to the depth cannula  134  of the measurement module  128  (see  FIG. 4 ). Here, the bearing region  184  essentially defines a “stepped” outer region of the shank  176  that affords rotational support along the length of the drill bit  66 , and has a larger diameter than adjacent distal and proximal regions of the shank  176  in the illustrated configuration. However, it will be appreciated that the bearing region  184  of the shank  176  of the drill bit  66  could be configured in other ways without departing from the scope of the present disclosure. Furthermore, while described as a drill bit  66  in the present disclosure, it is also contemplated that the drill bit  66  could have similar features and be configured as another suitable end effector, or rotary end-effector, such as a bur or reamer. 
     In the illustrated configuration, the drill bit  66  is formed as a single-piece component such that the distal end  180  of the shank  176  corresponds to or is otherwise disposed adjacent the cutting tip portion  70  of the drill bit  66 . However, it will be appreciated that the drill bit  66  could be manufactured in other ways, such as where the cutting tip portion  70  of the drill bit  66  is formed as a separate component from the shank  176  which is subsequently attached to the distal end  180  of the shank  176 . Nevertheless, for the purposes of clarity and consistency, the cutting tip portion  70  introduced above corresponds with the distal end  180  of the shank  176  in the illustrated configuration described herein. 
       FIGS. 20-23  generally depict the insertion portion  72  of the drill bit  66  which, as noted above, is configured to facilitate releasable attachment to the surgical handpiece assembly  62 . To this end, the interface  124  of the drill bit  66  is coupled to the shank  176  adjacent to but spaced distally from the proximal end  178  of the shank  176 . As is described in greater detail below, the interface  124  of the shank  176  is configured to facilitate rotationally locking the drill bit  66  to the surgical handpiece assembly  62  so that the surgical handpiece assembly  62  can rotate the drill bit  66  upon attachment. In order to axially lock the drill bit  66  to the surgical handpiece assembly  62 , the drill bit  66  further comprises a stop  186  and one or more resilient arms, generally indicated at  188 . The stop  186  is coupled to the shank  176  adjacent to and spaced distally from the interface  124 , and defines a stop surface  190  which has a tapered, generally frustoconical profile. As shown in  FIGS. 7F and 17C , the stop surface  190  is shaped and arranged to abut a correspondingly-shaped, tapered seat surface  192  of the proximal portion  116  of the drive cannula  114  to limit how far the drill bit  66  can be advanced axially into the surgical handpiece assembly  62 . The seat surface  192  may also be a transition surface tapering toward the axis AX distally to proximally to assist in guidance of the drill bit  66  through the bore  122  of the drive cannula  114 . However, it will be appreciated that the drill bit  66  of the present disclosure could be configured in other ways sufficient to limit how far the drill bit  66  can be axially advanced into the surgical handpiece assembly  62 . As is described in greater detail below, the resilient arm  188  is configured to axially retain the drill bit  66  to the drive cannula  114 . 
     With reference to  FIGS. 22-23 , the interface  124  of the drill bit  66  extends along the axis AX between a distal interface end  194  and a proximal interface end  196 . For the purposes of clarity and consistency, the distal interface end  194  and the proximal interface end  196  are defined herein as discrete locations along the length of the drill bit  66  between which the interface  124  has a generally consistent cross-sectional profile. However, it is contemplated that the distal interface end  194  and the proximal interface end  196  could be defined in other ways in some configurations. By way of illustrative example, it is conceivable that the interface  124  could comprise multiple discrete “interface regions” each having the same or different cross-sectional profiles which are delineated and spaced axially from each other along the shank  176 , such as with cylindrical portions of the shank  176  extending therebetween. Other configurations are contemplated. 
     In the configuration of the drill bit  66  illustrated in  FIGS. 22-23 , a transition region  198  extends from the proximal interface end  196  to the proximal end  178  of the shank  176 . Here, the transition region  198  effectively chamfers or “rounds-off” a portion of the interface  124  adjacent to the proximal end  178  of the shank  176  with a generally frustoconical profile to define the proximal interface end  196 . For the purposes of clarity and consistency, the proximal end  178  of the shank  176  illustrated herein is defined by the reduced diameter portion of the transition region  198  from which the resilient arms  188  extend. Put differently, the resilient arms  188  extend from the proximal end  178  of the shank  176  to respective arm ends  200 , and the proximal end  178  of the shank  176  is distal from the arm ends  200 . The resilient arms  188  will be described in greater detail below. 
     As noted above, the illustrated configuration of the bore  122  of the proximal portion  116  of the drive cannula  114  of the surgical handpiece assembly  62  has a generally rounded, hexagonal profile defined by six bore flats  122 F and six bore corners  122 C (see  FIG. 18A ), and the interface  124  of the drill bit  66  is configured to be received within the bore  122  to promote concurrent rotation between the drill bit  66  and the drive cannula  114  about the axis AX. To this end, the interface  124  of the drill bit  66  comprises at least one outermost drive portion  202  which is spaced from the axis AX at a first interface distance  204  (depicted schematically in  FIGS. 29-33 ). In some configurations, the outermost drive portion  202  of the interface  124  is defined by an outer drive surface  206  facing away from the axis AX. Regardless, for the purposes of clarity and consistency, the first interface distance  204  and the outermost drive portion  202  are defined by whichever edge, apex, point, or surface of the interface  124  is spaced furthest from the axis AX. In some configurations, the interface  124  comprises a first outermost drive portion spaced from the axis AX at a first interface distance and a second outermost drive portion spaced from the axis AX at a second interface distance to define a maximum drive dimension  208  of the interface  124  (depicted schematically in  FIGS. 29-33 ). In these configurations, the maximum drive dimension  208  is the “widest” portion of the interface  124 . The first and second interface distances may comprise a common distance at which each of the first and second outermost drive portions is spaced from the axis AX, such that the arrangement of the first and second outermost drive portions relative to the axis AX is symmetrical. However, in other configurations, the first and second interface distances may not be equal to one another, such that the arrangement of the first and second outermost drive portions may be asymmetrical relative to the axis AX. 
     In some configurations, the interface  124  comprises at least one outer non-drive portion  210  which is spaced from the axis AX at a third interface distance  212  (depicted schematically in  FIGS. 29-33 ). Further still, in some configurations, the outer non-drive portion  210  of the interface  124  is defined by an outer non-drive surface  214  which, in some configurations, may be defined as a planar interface surface. Regardless, for the purposes of clarity and consistency, the third interface distance  212  and the outer non-drive portion  210  are defined by whichever edge, apex, point, or surface of the interface  124  is spaced closest to the axis AX. In some configurations, the interface  124  comprises a first outer non-drive portion spaced from the axis AX at a third interface distance  212  and a second outer non-drive portion spaced from the axis AX at a fourth interface distance  212  to define a minimum interface dimension  216  of the interface  124  (depicted schematically in  FIGS. 29-33 ). In these configurations, the minimum interface dimension  216  is the “narrowest” portion of the interface  124 . The third and fourth interface distances may comprise a common distance at which each of the first and second outer non-drive portions is spaced from the axis AX, such that the arrangement of the first and second outer non-drive portions relative to the axis AX is symmetrical. However, in other configurations, the third and fourth interface distances may not be equal to one another, such that the arrangement of the first and second outer non-drive portions may be asymmetrical relative to the axis AX. Further still, two outer non-drive portions  210  are radially spaced about the axis AX from two outermost drive portions  202 . However, as will be appreciated from the subsequent description below, the interface  124  could be configured in other ways sufficient to be received within and rotate concurrently with the bore  122  of the proximal portion  116  drive cannula  114 . 
     By way of illustrative example of the features of the interface  124  introduced above, the interface  124  of the configuration of the drill bit  66  depicted in  FIGS. 18C and 20-24B , and depicted schematically in  FIGS. 29 and 30 , has a generally rounded hexagonal profile comprising a total of six outermost drive portions  202  and a total of six outer non-drive portions  210 . Here, the six outermost drive portions  202  are each respectively defined by an outer drive surface  206  which is rounded to define a corner  218 . Thus, in this configuration, the maximum drive dimension  208  is defined between the apexes of two diametrically opposed corners  218 . Furthermore, in this configuration, the six outer non-drive portions  210  are each respectively defined by an outer non-drive surface  214  which is substantially flat to define a planar surface  220 . Thus, in this configuration, the minimum interface dimension  216  is defined between the midpoints of two diametrically opposed planar surfaces  220 . 
     As is described in detail below in connection with  FIGS. 29-33 , the interface  124  of the drill bit  66  of the present disclosure could have a number of different cross-sectional profiles or configurations sufficient to be received within and rotate concurrently with the bore  122 . Thus, while the illustrated configurations of the interface  124  depicted in  FIGS. 2, 4-5, 7C-7I, 15B, 17C, 18B-18C, and 20-30  have a generally rounded hexagonal profile which is complementary to the profile of the bore  122  as described above, other configurations are contemplated by the present disclosure, including without limitation: other generally polygonal profiles such as a rectangle (see  FIG. 31 ) or a star (see  FIG. 32 ), irregular polygons, and/or other profiles and/or shapes which can be removably received within and rotate concurrently with the hexagonal bore  122  of the proximal portion  116  of the drive cannula  114  (see  FIG. 33 ). 
     As noted above, the drill bit  66  of the present disclosure comprises one or more resilient arms  188  which extend from the proximal end  178  of the shank  176  to respective arm ends  200 . The resilient arms  188  of the drill bit  66  are provided to, among other things, facilitate axially retaining the drill bit  66  to the surgical handpiece assembly  62  when the stop surface  190  of the drill bit  66  abuts the seat surface  192  of the proximal portion  116  of the drive cannula  114 . As will be appreciated from the subsequent description below, the resilient arms  188  could be formed integrally with the shank  176  and could be machined, bent, and the like, or the resilient arms  188  could be formed separately from and subsequently attached to the shank  176 , such as via welding, brazing, adhering, bonding, or any suitable process sufficient to operatively attach the resilient arms  188  to the shank  176 . 
     With reference to  FIGS. 20-23 , the illustrated configuration of the insertion portion  72  of the drill bit  66  comprises resilient arms  188  which each have an outer arm surface  222  facing away from the axis AX, and a retention surface  224  facing toward the distal end  180  of the shank  176  (see  FIG. 23 ). As is described in greater detail below in connection with  FIGS. 29-33 , the retention surface  224  of the resilient arm  188  is arranged so as to be radially aligned about the axis AX with one of the outermost drive portions  202  of the interface  124 . Furthermore, as is described in greater detail below in connection with  FIGS. 7A-7I, 15A-19C , and  29 - 33 , the resilient arm  188  is configured so as to be movable relative to the axis AX between a first position P 1  (see  FIGS. 7B and 22 ) and a second position P 2  (see  FIGS. 7D-7E ). In the first position P 1 , the outer arm surface  222  is spaced from the axis AX at a first arm distance  226  which is greater than the first interface distance  204 . In the second position P 2 , the outer arm surface  222  is spaced from the axis AX at a second arm distance  228  which is less than the first arm distance  226  and, in some configurations, is less than or equal to the first interface distance  204 . Put differently, the outer arm surface  222  of the resilient arm  188  is spaced further from the axis AX than any portion of the interface  124 , and the resilient arm  188  is deflectable relative to the axis AX from the first position P 1  toward the second position P 2 , and is resiliently biased toward the first position P 1 . As is described in greater detail below, this configuration helps facilitate releasable axial retention of the drill bit  66  to the surgical handpiece assembly  62  and, in some configurations, also affords self-aligning functionality to the drill bit  66  so as to index the interface  124  to the bore  122  by promoting rotation of the drill bit  66  about the axis AX during attachment to the surgical handpiece assembly  62  (see  FIGS. 24A-24B , described in greater detail below). 
     Continuing the previous example above where the interface  124  comprises first and second outermost drive portions, the retention surface may be radially aligned with the first outermost drive portion. The outer arm surface  222  of the resilient arm  188  in the first position P 1  may be spaced from the axis AX at the first arm distance, which may be greater than the first interface distance at which the first outermost drive portion is spaced from the axis AX. Furthermore, the outer arm surface  222  of the resilient arm  188  in the second position P 2  may be spaced from the axis AX at the second arm distance, which may be less than the first arm distance and less than or equal to the first interface distance. 
     In another configuration, where the interface  124  comprises first and second outermost drive portions, the retention surface may not be radially aligned with the first outermost drive portion. Rather, the retention surface may be radially aligned with the second outermost drive portion. The outer arm surface  222  of the resilient arm  188  in the first position P 1  may be spaced from the axis AX at a first arm distance, which in this configuration is greater than the second interface distance at which the second outermost drive portion is spaced from the axis AX. Furthermore, the outer arm surface  222  of the resilient arm  188  in the second position P 2  may be spaced from the axis AX at a second arm distance, which is less than the first arm distance and less than or equal to the second interface distance. 
     As is best shown in  FIG. 23 , the outer arm surface  222  in the illustrated configuration is generally rectangular in profile, when viewed from the top, and is arranged between the arm end  200  and the retention surface  224 . However, it will be appreciated that the outer arm surface  222  could be realized with other configurations, profiles, arrangements, and the like. For the purposes of clarity and consistency, the outer arm surface  222  is defined by whichever surface, face, edge, apex, or point of the resilient arm  188  that is spaced furthest from the axis AX when the resilient arm  188  is in the first position P 1 . 
     With continued reference to  FIGS. 20-23 , the resilient arm  188  further comprises a ramp surface  230  which extends distally from the arm end  200  and merges with the outer arm surface  222 . The ramp surface  230  is shaped and arranged so as to deflect the resilient arm  188  relative to the axis AX in response to engagement, contact, abutment, and the like. By way of example, in the illustrated configuration, the ramp surface  230  is shaped and arranged to engage against the tapered seat surface  192  of the proximal portion  116  of the drive cannula  114  (see  FIG. 7C ) in order to move the resilient arm  188  from the first position P 1  to the second position P 2  as the drill bit  66  is attached to the surgical handpiece assembly  62  (sequentially compare  FIGS. 7B-7D ). Similarly, in the illustrated configuration, the ramp surface  230  is shaped and arranged to engage the actuating element  174  of the release assembly  150  (see  FIGS. 7G-7H ) as the release member  164  translates distally along the axis AX in order to move the resilient arm  188  toward the second position P 2  to facilitate removing the drill bit  66  from the surgical handpiece assembly  62  (sequentially compare  FIGS. 7F-7I ). 
     Referring now to  FIGS. 20-24B , the illustrated configuration of the resilient arm  188  comprises an arm body  232  and a finger portion, generally indicated at  234 . In one exemplary configuration, the arm body  232  has a generally linear profile with a generally arcuate portion which merges with the proximal end  178  of the shank  176 . As best shown in  FIG. 22 , the arm body  232  extends away from the proximal end  178  of the shank  176 . In the illustrated configuration, this configuration places the retention surface  224  at an arm position angle  236  (see  FIG. 22 ) defined relative to the axis AX, which is generally oblique when the resilient arm  188  is in the first position P 1  and which is generally perpendicular when the resilient arm  188  is in the second position P 2 . However, as will be appreciated from the subsequent description of the interaction between the insertion portion  72 , the proximal portion  116  of the drive cannula  114 , and the output hub  96 , the retention surface  224  could be arranged or configured in other ways, such as to be at a non-perpendicular angle relative to the axis AX when the resilient arm  188  is in the second position P 2 . Other configurations are contemplated. Furthermore, while the arm body  232  extends away from the axis AX toward the arm end  200  in the illustrated configuration, it is conceivable that the arm body  232  could extend generally parallel with the axis AX in alternate configurations of the drill bit  66 . In other configurations, the retention surface  224  can be arranged or configured relative to the resilient arm  188 , such that the retention surface  224  is arranged at an 80-degree angle relative to the resilient arm  188 . However, the retention surface can instead by arranged at any suitable angle above or below 80 degrees relative to the resilient arm. 
     The finger portion  234  of the resilient arm  188  is formed at the arm end  200  and, in the illustrated configurations, provides or otherwise defines the outer arm surface  222 , the retention surface  224 , and the ramp surface  230 . As shown in  FIG. 22 , the finger portion  234  protrudes generally away from the axis AX to the outer arm surface  222 . As shown in  FIG. 23 , the finger portion  234  defines a pair of outer finger surfaces  238  which are spaced at a finger width  240  from one another and are generally perpendicular to the retention surface  224 . However, it will be appreciated that the finger portions  234  could be configured in a number of different ways, such as with a triangular profile, a rectangular profile, a rounded profile, a pentagonal profile, or other suitable profiles. 
     In the illustrated configuration, the finger portion  234  further comprises an aligning element, generally indicated at  242 , arranged adjacent to the arm end  200 . The aligning element  242  may be positioned at different locations on the resilient arm  188  besides the finger portion  234 . Furthermore, fewer than all of the resilient arms  188  may include the aligning element  242 . As will be appreciated from the subsequent description below, the aligning element  242  may comprise at least a portion of the outer arm surface  222 , at least a portion of the ramp surface  230 , and/or one or more planar arm surfaces  244  arranged adjacent to the outer arm surface  222  and to the ramp surface  230  (see  FIGS. 20-23 . Here, the planar arm surfaces  244  are arranged so as to be generally coplanar with respective planar surfaces  220  of outer non-drive surfaces  214  of the interface  124  when the resilient arm  188  is in the second position P 2  (see  FIG. 24B ). In some configurations, the aligning element  242  may comprise a single planar arm surface  244 . Moreover, while the illustrated configuration of the aligning element  242  employs a generally planar outer arm surface  222  arranged between two planar arm surfaces  244 , it will be appreciated that other configurations are contemplated. By way of non-limiting example, the outer arm surface  222  could be realized as a discrete edge or point defined by a non-planar arm surface, formed such as with a wedge shape, where the discrete edge or point is arranged in radial alignment (e.g., co-linear with) one of the outermost drive portions  202  of the interface  124  when the resilient arm  188  is in the second position P 2 . In some configurations, such as those illustrated throughout the drawings, the aligning element  242  is shaped so as to mimic, mirror, or otherwise complement the interface  124  when the resilient arm  188  is in the second position P 2 . Other configurations are contemplated, such as where the interface  124  is configured with a star-shaped profile with a plurality of drive lobes  245  spaced about the axis AX, such as the configuration illustrated in  FIG. 32 , the aligning element  242  may have a profile which at least partially replicates or otherwise complements one of the drive lobes  245  (e.g., a triangular profile). 
     The aligning element  242  is employed to facilitate at least partial rotation of the drill bit  66  about the axis AX as the resilient arm  188  moves from the first position P 1  to the second position P 2  in response to force applied to the drill bit  66  along the axis AX during attachment to the surgical handpiece assembly  62 . More specifically, as shown in  FIGS. 24A-24B , as the resilient arm  188  moves toward the second position P 2  in response to engagement with the tapered seat surface  192  of the proximal portion  116  of the drive cannula  114 , one or more portions of the aligning element  242  are disposed in abutment with the tapered seat surface  192 . Here, because potential energy is stored in the resilient arm  188  when deflected away from the first position P 1 , the abutment between the tapered seat surface  192  and one or more portions of the aligning element  242  promotes at least partial rotation of the drill bit  66  relative to the drive cannula  114  as the aligning element  242  is advanced from the tapered seat surface  192  of the proximal portion  116  of the drive cannula  114  into the bore  122  of the proximal portion  116  of the drive cannula  114 . Thus, as the resilient arm  188  enters the bore  122 , the drill bit  66  “self-aligns” with the bore  122  in that the rotation of the drill bit  66  about the axis AX is caused by the outer arm surface  222  being urged toward one of the bore corners  122 C, and the planar arm surfaces  244  of the aligning element  242  are brought into respective engagement with the adjacent bore flats  122 F (compare  FIGS. 24A-24B ). 
     In this configuration, the resilient arm  188  moves from the first position P 1  at the first arm distance relative to the axis AX indirectly to the second position P 2  ( FIG. 24B ) at the second arm distance relative to the axis AX. More specifically, the resilient arm  188  can move from the first position P 1  directly to a third position P 3  ( FIG. 24A ) at a third distance relative to the axis AX and from the third position P 3  directly to the second position P 2  ( FIG. 24B ). The first arm distance relative to the axis AX may be greater than the first interface distance  204  between the outermost drive portion  202  and the axis AX. The third arm distance relative to the axis AX may be less than each of the first arm distance and the first interface distance  204 . The second arm distance relative to the axis AX may be greater than the third arm distance and less than or equal to the first interface distance  204 . 
     When the resilient arm  188  is disposed in the third position, the outer arm surface  222  engages one of the bore flats  122 F. Because the resilient arm  188  is urged away from the axis AX, movement of the outer arm surface  222  from the bore flat  122 F to one of the bore corners  122 C causes the resilient arm  188  to move from the third position ( FIG. 24A ) to the second position P 2  ( FIG. 24B ) which, in turn, causes the drill bit to rotate into alignment with the bore. However, it is contemplated that, when the drill bit is already aligned with the bore prior to insertion into the bore and force is applied to the drill bit  66  along the axis AX, the resilient arm can move from the first position P 1  directly to the second position P 2 . 
     Because the planar arm surfaces  244  are generally coplanar with planar surfaces  220  of the interface  124  when the resilient arm  188  is in the second position P 2 , the rotation described above “indexes” the interface  124  of the drill bit  66  with the bore  122  of the proximal portion  116  of the drive cannula  114  once the finger portion  234  is received within the bore  122  and the outer arm surface  222  is received in one of the bore corners  122 C. While this configuration affords advantages in connection with attaching the end effector assembly  64  to the surgical handpiece assembly  62 , by “self-aligning” the interface  124  of the drill bit  66  with the bore  122  of the proximal portion  116  of the drive cannula  114 , it will be appreciated that the drill bit  66  could be configured in other ways, such as with different types of aligning elements  242  and/or finger portions  234 . By way of non-limiting example, the drill bit  66  could omit the aligning element  242  and/or the finger portions  234  in some configurations. Other configurations are contemplated. 
     Referring now to  FIGS. 15A-19C , as noted above, the proximal portion  116  of the drive cannula  114  cooperates with the output hub  96  of the actuator assembly  82  to facilitate rotating the drill bit  66  about the axis AX via splined engagement between the output hub  96  and the drive cannula  114 . As is best shown in  FIGS. 15A and 17A , the output hub  96  extends between a distal hub end  246  and a proximal hub end  248 , and comprises one or more internal splines  250  which extend from the distal hub end  246 , adjacent to the integrated carrier  104 , toward but spaced from the proximal hub end  248 . Here, the output hub  96  is provided with a lockout taper  252  which has a generally frustoconical profile extending internally to merge with the internal splines  250  such that the internal splines  250  terminate distal from the proximal hub end  248 . 
     With continued reference to  FIGS. 15A and 17A , the proximal portion  116  of the drive cannula  114  extends between a distal end  254  of the proximal portion  116  of the drive cannula  114  and a proximal end  256  of the proximal portion  116  of the drive cannula  114 . Here, the tapered seat surface  192  is formed at the distal end  254  and tapers internally into the hexagonal bore  122 , as noted above. The bore  122 , in turn, extends along the axis AX toward the proximal end  256 . In some configurations, the proximal portion  116  of the drive cannula  114  is provided with a release taper  258  which similarly tapers internally into the hexagonal bore  122  (see  FIG. 17A ) to help facilitate releasing the drill bit  66  from the surgical handpiece assembly. The splined engagement is facilitated by one or more grooves formed by the external surface of the proximal portion  116  of the drive cannula  114  or one or more projections extending from the external surface of the proximal portion  116  of the drive cannula  114 . In one configuration shown in  FIG. 15A , the one or more projections comprise external splines  260  which are formed extending from the proximal end  256  toward but spaced from the distal end  254 . At the proximal end  256 , the external splines  260  define lock surfaces  262  adjacent to the release taper  258 . The lock surfaces  262  are arranged to abut the retention surface  224  of the resilient arm  188  to axially lock the drill bit  66  to the surgical handpiece assembly  62 . The specific shape and arrangement of the internal splines and external splines can be adjusted to different arrangements or geometries so long as the lock surfaces are still present and arranged relative to the bore in a way that makes the lock surfaces accessible to the retention surfaces of the bit when the drive interface is received in the bore. In some configurations, the release taper  258  and lock surfaces  262  are integral and cooperate to form a retention surface of the proximal portion  116  of the drive cannula  114  that is configured to abut the retention surface  224  of the resilient arm  118 . The retention surface of the proximal portion  116  of the drive cannula  114  tapers away from the axis AX proximally to distally to prevent accidental release of the drill bit  66  from the drive cannula  114 . 
     In one configuration shown best in  FIGS. 15B, 17A, and 17C , the proximal end  256  is spaced distally from the proximal hub end  248  of the output hub  96 . The lock surfaces  262  of the proximal portion  116  of the drive cannula  114  are likewise spaced distally from the proximal hub end  248  and, the lock surfaces  262  are also spaced distally from the lockout taper  252  of the output hub  96 . This configuration ensures that axial retention of the drill bit  66  is effected via engagement between the retention surface  224  of the resilient arm  188  and one of the lock surfaces  262  of the proximal portion  116  of the drive cannula  114 , and not with other portions of the proximal portion  116  of the drive cannula  114  or the output hub  96 . Put differently, the lockout taper  252  of the output hub  96  and the release taper of the proximal portion  116  of the drive cannula  114  are arranged and configured not to remain in abutting engagement with the retention surface  224  of the resilient arm  188  in a way that would allow the drill bit  66  to be axially retained. Moreover, as is generally depicted in  FIGS. 17A-19C , the external splines  260  of the proximal portion  116  of the drive cannula  114  are radially arranged about the axis AX relative to the bore  122 . Thus, because the external splines  260  of the proximal portion  116  of the drive cannula  114  define the lock surfaces  262  and are radially arranged with the bore  122  adjacent to the bore corners  122 C, the retention surface  224  of the resilient arm  188  needs to be radially aligned about the axis with the outermost drive portion  202  of the interface  124  in order to engage one of the lock surfaces  262 . The specific shape and arrangement of the proximal portion  116  of the drive cannula  114  and the output hub  96  can be adjusted to different arrangements or geometries so long as the lock surfaces are still present and arranged relative to the bore in a way that makes the lock surfaces accessible to the retention surfaces of the bit when the drive interface is received in the bore. 
     Referring now to  FIG. 15D , an alternative embodiment of the drive cannula and the output hub is illustrated and described. The proximal portion  116 ′ of the drive cannula  114 ′ cooperates with the output hub  96 ′ of the actuator assembly to facilitate rotating the drill bit about the axis AX via splined engagement between the output hub  96 ′ and the drive cannula  114 ′. The output hub  96 ′ extends between a distal hub end  246 ′ and a proximal hub end  248 ′, and comprises one or more internal splines  250 ′ which extend from the distal hub end  246 ′, adjacent to the integrated carrier  104 ′, toward but spaced from the proximal hub end  248 ′. Between each pair of the splines  250 ′, there may be a recess  251 . Aligned with those recesses axially, there may be a pocket  253  that provides additional clearance for the resilient arms to flex outward. Here, the output hub  96 ′ is provided with a lockout taper  252 ′ which has a generally frustoconical profile extending internally to merge with the internal splines  250 ′ such that the internal splines  250 ′ terminate distal from the proximal hub end  248 ′. 
     With continued reference to  FIG. 15D , the proximal portion  116 ′ of the drive cannula  114 ′ extends between a distal end  254 ′ of the proximal portion  116 ′ of the drive cannula  114 ′ and a proximal end  256 ′ of the proximal portion  116 ′ of the drive cannula  114 ′. Here, the tapered seat surface is formed at the distal end  254  and tapers internally into the hexagonal bore  122 ′, as noted above. The bore  122 ′, in turn, extends along the axis AX toward the proximal end  256 ′. In some configurations, the proximal portion  116 ′ of the drive cannula  114 ′ is provided with a release taper  259  which similarly tapers internally into the hexagonal bore to help facilitate releasing the drill bit from the surgical handpiece assembly. The splined engagement is facilitated by one or more grooves formed by the external surface of the proximal portion of the drive cannula  114 ′ or one or more projections extending from the external surface of the proximal portion  116  of the drive cannula  114 . In one configuration, shown in  FIG. 15D , the one or more projections comprise external splines  260 ′ which are formed extending from the proximal end  256 ′ toward but spaced from the distal end  254 ′. At the proximal end  256 ′, the external splines  260 ′ define lock surfaces  262 ′ adjacent to the release taper  259 . The lock surfaces  262 ′ are radially and at least partially axially aligned with the lock surfaces  262 ′. The release taper  259  may be defined by protrusions  261  that extend proximally relative to the lock surfaces  262 ′. The lock surfaces  262 ′ are arranged to abut the retention surface  224  of the resilient arm  188  to axially lock the drill bit  66  to the surgical handpiece assembly  62 . The specific shape and arrangement of the internal splines and external splines can be adjusted to different arrangements or geometries so long as the lock surfaces are still present and arranged relative to the bore in a way that makes the lock surfaces accessible to the retention surfaces of the bit when the drive interface is received in the bore. In some configurations, the release taper  259  and lock surfaces  262 ′ are integral and cooperate to form a retention surface of the proximal portion  116 ′ of the drive cannula  114 ′ that is configured to abut the retention surface of the resilient arm. The lock surface of the proximal portion  116 ′ of the drive cannula  114  may be perpendicular to the axis AX proximally to distally to prevent accidental release of the drill bit from the drive cannula  114 ′. 
     In this configuration, the proximal end  256 ′ is spaced distally from the proximal hub end  248 ′ of the output hub  96 ′. The lock surfaces  262 ′ of the proximal portion  116 ′ of the drive cannula  114 ′ are likewise spaced distally from the proximal hub end  248 ′ and, the lock surfaces  262 ′ are also spaced distally from the lockout taper  252 ′ of the output hub  96 ′. The release taper  259  and thus, the proximal end of the protrusion  261  is also spaced distally from the lockout taper  252  of the output hub  96 ′. This configuration ensures that axial retention of the drill bit is effected via engagement between the retention surface of the resilient arm and one of the lock surfaces  262 ′ of the proximal portion  116 ′ of the drive cannula  114 ′, and not with other portions of the proximal portion  116 ′ of the drive cannula  114 ′ or the output hub  96 ′. Put differently, the lockout taper  252 ′ of the output hub  96 ′ and the release taper  259  of the drive cannula  114 ′ are arranged and configured not to remain in abutting engagement with the retention surface of the resilient arm in a way that would allow the drill bit to be axially retained. Because the lock surfaces  262 ′ are radially arranged with the bore  122 ′ adjacent to the bore corners  122 C, the retention surface of the resilient arm needs to be radially aligned about the axis with the outermost drive portion of the interface in order to engage one of the lock surfaces. 
     As will be appreciated from the subsequent description below, the insertion portion  72  of the drill bit  66  may be configured in different ways sufficient to releasably attach to the surgical handpiece assembly. By way of non-limiting example, in some of the illustrated configurations, such as those depicted in  FIGS. 20-23 , the insertion portion  72  comprises a pair of generally identical, diametrically opposed resilient arms  188 , each having respective retention surfaces  224  radially aligned with respective outermost drive portions  202  of the interface  124 . However, it will be appreciated that other configurations are contemplated. By way of non-limiting example, it is conceivable that the insertion portion  72  could comprise two resilient arms  188  which are radially spaced from outermost drive portions  202  about the axis AX at 60 degrees, or at intervals thereof (generally illustrated schematically in  FIGS. 30 and 32-33 ). Other intervals are contemplated, such as 15 degrees, 30 degrees, 45 degrees, or intervals of each. In some configurations, the resilient arm  188  and one of the outermost drive portions  202  are positioned within 15 degrees of one another relative to the axis AX. 
     Furthermore, it is conceivable that the insertion portion  72  could comprise a plurality of resilient arms  188  with different or similar configurations from one another, such as with differently shaped, sized, or angled retention surfaces  224 , finger portions  234 , aligning elements  242 , and the like (illustrated schematically in  FIG. 30 ). Further still, it will be appreciated that the insertion portion  72  could comprise a single resilient arm  188 , such as is depicted in the configuration illustrated in  FIGS. 25-26 , or could comprise more than two resilient arms  188 , such as is depicted in the configuration illustrated in  FIGS. 27-28  which comprises three resilient arms  188 . Furthermore, the configurations of the interface  124  illustrated schematically in  FIGS. 32-33  could each have between one and six resilient arms  188 . Moreover, while some of the configurations of the interface  124  comprise resilient arms  188  which are diametrically spaced from each other about the axis AX and have similar or identical profiles, other arrangements are contemplated. By way of example, the interface  124  illustrated schematically in  FIG. 30  is shown as being able to comprise five resilient arms  188  of various configurations (e.g., with retention surfaces  224  of different profiles and orientations). Other configurations are contemplated. 
     While the illustrated drill bit  66  is configured as a twist drill with helical flutes  182  to promote tissue penetration, other types of cutting tip portions  70  could be employed in some configurations. For example, the cutting tip portion  70  could be realized as a burr, a reamer, a tap, a screwdriver, and the like. Moreover, as shown in the configuration illustrated in  FIG. 28 , the drill bit  66  may further comprise a drill cannula  264  extending along the axis AX such that the drill bit  66  is cannulated in some configurations. 
     As noted above, the interface  124  of the drill bit  66  of the present disclosure could have a number of different cross-sectional profiles or configurations sufficient to be received within and rotate concurrently with the bore  122 . In some configurations, the interface  124  may comprise different numbers of planar surfaces  220 . By way of illustration, the configurations of the interface  124  illustrated in  FIGS. 29-32  each comprise at least four planar surfaces  220 : six in the configurations illustrated in  FIGS. 29-30 , four in the configuration illustrated in  FIG. 31 , and twelve in the configuration illustrated in  FIG. 32 . However, other configurations may employ fewer than four planar surfaces  220 , such as the configuration illustrated in  FIG. 33  which comprises two planar surfaces. It will be appreciated that other arrangements and configurations of the interface  124  and/or the planar surfaces  220  are contemplated. 
     In some configurations, the interface  124  may comprise different numbers of corners  218  which define the outermost drive portions  202 . By way of illustration, the configurations of the interface  124  illustrated in  FIGS. 29-30  are generally hexagonal and each comprise six corners  218  which define outermost drive portions  202 . The interface  124  illustrated in  FIG. 31  is generally rectangular and comprises four corners  218  which define outermost drive portions  202 . The interface  124  illustrated in  FIG. 32  is generally star-shaped and comprises six drive lobes  245 , each of which comprises a corner  218  which defines an outermost drive portion  202 . In configurations where the interface  124  comprises drive lobes  245  which terminate at corners  218  defined such as by points or apexes, at least two drive lobes  245  may define outermost drive portions  202 . However, as noted above, other configurations are contemplated, such as where the interface  124  comprises three drive lobes  245 , more than four drive lobes  245 , and the like. The interface illustrated in  FIG. 33  comprises an irregular shape which comprises a single corner  218  defining an outermost drive portion  202 . It will be appreciated that other arrangements and configurations of the corners  218  and/or the outermost drive portions  202  are contemplated. 
     Referring now to the configuration of the insertion portion  72  of the drill bit  66  depicted schematically in  FIG. 29 , one of the retention surfaces  224  of the resilient arms  188  and one of the outer drive surfaces  206  of the outermost drive portions  202  of the interface  124  comprise, define, or are otherwise aligned with a common bisecting plane CBP intersecting the axis AX to define two equal portions of the retention surface  224  and the resilient arm  188  and two equal portions of the outer drive surface  206  and the outermost drive portion  202 . It will be appreciated that the symmetrical relationship described above is exemplary, and other configurations are contemplated. 
     Referring now to the configuration of the insertion portion  72  of the drill bit  66  depicted schematically in  FIG. 32 , one of the retention surfaces  224  of one of the resilient arms  188  and one of drive lobes  245  comprise, define, or are otherwise aligned with a common bisecting plane CBP intersecting the axis AX to define two equal portions of the retention surface  224  of the resilient arm  188  and two equal portions of the outermost drive portion  202  (here, defined by the apexes of the triangular drive lobes  245 ). Here too, it will be appreciated that the symmetrical relationship described above is exemplary, and other configurations are contemplated. 
     Referring now to the configuration of the insertion portion  72  of the drill bit  66  depicted schematically in  FIG. 31 , one of the retention surfaces  224  of the resilient arms  188  comprises, defines, or is otherwise aligned with a first bisecting plane FBP that intersects the axis AX to define two equal portions of the retention surface  224 . Furthermore, one of the outermost drive portions  202  of the interface  124  comprises, defines, or is otherwise aligned with a second bisecting plane SBP that intersects the axis AX to define two equal portions of the outermost drive portion  202  (here, defined by the apexes of two of the corners  218  of the rectangular profile). In this configuration, the second bisecting plane SBP is radially spaced approximately 60 degrees from the first bisecting plane FBP about the axis AX. Thus, as noted above, the retention surface  224  of the resilient arm  188  may be radially aligned with the outermost drive portion  202  of the interface  124  at intervals of approximately 60 degrees. Here too, other configurations are contemplated. 
     Referring now to  FIG. 2 , in one configuration, the interface  124  has an interface length IL defined between the distal interface end  194  and the proximal interface end  196 , and the shank  176  has a shank length SL defined between the distal end  180  and the proximal end  178 , with the shank length SL being greater than or equal to three times the interface length IL. However, those having ordinary skill in the art will appreciate that other configurations are contemplated for the drill bit  66 , such as with a shank length SL is five or more times the interface length IL. Referring now to  FIG. 22 , in the illustrated configuration, the retention surface  224  is spaced from the proximal interface end  196  at a retention distance RD that is greater than or equal to the interface length IL. Here too, other configurations are contemplated. 
     Referring now to  FIGS. 1-2 and 34 , as noted above, in some configurations, the tip protector  68  of the end effector assembly  64  is provided to facilitate releasably attaching the drill bit  66  to the drive cannula  114  of the surgical handpiece assembly  62  such that the tip protector  68  at least partially conceals the cutting tip portion  70  of the drill bit  66 . Thus, a user can grasp the tip protector  68  and thereby handle the drill bit  66  to facilitate attachment with the surgical handpiece assembly  62 , without contacting the cutting tip portion  70 , before subsequently removing the tip protector  68  from the cutting tip portion  70 . To this end, as shown in  FIG. 36 , the tip protector  68  generally comprises a handle  266  configured to be grasped by the user, and a receptacle  268  capable of receiving the cutting tip portion  70  of the drill bit  66 . 
     In the configuration of the tip protector  68  illustrated in  FIGS. 1-2 and 34-36 , and as is best depicted in  FIG. 36 , the handle  266  comprises a first handle body  270  and a second handle body  272  which are operatively attached together axially, such as via a press-fit engagement. The first handle body  270  defines a handle bore  274  extending along a handle axis HA. A receiver  276  is rotatably supported within the handle bore  274  and comprises the receptacle  268  which is capable of receiving the cutting tip portion  70  of the drill bit  66 , such as via a friction-fit engagement. In this configuration, the receiver  276  comprises a flange  278  which abuts a portion of the first handle body  270  adjacent to the second handle body  272 . The second handle body  272  comprises an inlet mouth  280  which tapers inwardly to a stepped region  282  which, in turn, is disposed adjacent to the flange  278  of the receiver  276  to define a recess  284  between the first handle body  270  and the stepped region  282 . The flange  278  is disposed within the recess  284  such that the receiver  276  constrained form translating along the handle axis HA and out of the handle bore  274 . Thus, the receiver  276  is able to rotate about the handle axis HA within the handle bore  274  without rotating the handle  266 . 
     When the cutting tip portion  70  is disposed within the receptacle  268 , the drill bit  66  effectively rotates concurrently with the receiver  276  about the handle axis HA. Here, the user can grasp the handle  266  and attach the drill bit  66  to the surgical handpiece assembly  62  without contacting the cutting tip portion  70 . Moreover, the relative rotation afforded between the handle  266  and the drill bit  66  in this configuration complements the “self-aligning” features of drill bit  66  described above in connection with  FIGS. 24A-24B . Specifically, the indexing of the interface  124  relative to the bore  122  via the aligning element  242  can occur without translating rotation back to the handle  266  in this configuration, which promotes attachment of the drill bit  66  to the surgical handpiece assembly  62  in an efficient manner. 
     As noted above, the tip protector  68  can be configured in a number of different ways to promote handling of the drill bit  66 . For example, in the configuration of the tip protector  68  depicted in  FIGS. 37-38 , the first handle body  270  and the second handle body  272  of the handle  266  are operatively attached together laterally, such as via interlocking features, adhesion, bonding, and the like. In this configuration, the recess  284  is likewise provided to accommodate the flange  278  so as to restrict axial movement of the receiver  276  relative to the handle  266 , and the receptacle  268  is similarly configured to releasably secure to the cutting tip portion  70  of the drill bit, such as by frictional engagement. 
     The configuration of the tip protector  68  depicted in  FIGS. 39-40  is realized as a unitary, one-piece component such that the handle  266  defines the receptacle  268 , which may be utilized in connection with configurations where relative rotation between the handle  266  and the drill bit  66  is undesirable or unnecessary. In some configurations, such as those comprising single-piece tip protectors  68 , at least a portion of the tip protector  68  may be resiliently deformable, may be tapered or stepped to accommodate cutting tip portions  70  of different sizes, and the like. It will be appreciated that these features could also be utilized in connection with other types of tip protectors  68  illustrated herein. 
     The configuration of the tip protector  68  depicted in  FIGS. 41-42  employs a unitary, one-piece handle  266  in which a magnet  286  is disposed. Here, the receptacle  268  is likewise defined by the handle  266 , and extends along the handle axis HA between the magnet  286  and the inlet mouth  280 . Where the drill bit  66  is manufactured from a ferromagnetic material, the magnet  286  will attract the cutting tip portion  70  to promote releasable retention between the tip protector  68  and the drill bit  66 . Here, it will be appreciated that the receptacle  268  may be sized so as to permit a looser fit with the drill bit  66  and thereby facilitate relative rotation between the drill bit  66  and the handle  266  while axially retaining the drill bit  66  via the magnet  286 . In some configurations, such as where the magnet  286  is relatively strong, the receptacle  268  may be sized to receive cutting tip portions  70  of various sizes, diameters, and the like. 
     The configuration of the tip protector  68  depicted in  FIGS. 43-44  employs a handle  266  which is configured similarly to the configuration of the tip protector  68  described above in connection with  FIGS. 35-36 . In this configuration, however, a sleeve  288  is supported in the first handle body  270 . Here, the sleeve  288  rotatably supports the receiver  276  and cooperates with the second handle body  272  to define the recess  284  in which the flange  278  is disposed. Similar to the configuration of the tip protector  68  described above in connection with  FIGS. 41-42 , magnets  286  are likewise employed to help retain the cutting tip portion  70  of the drill bit  66 . In this configuration, however, magnets  286  are also disposed radially about the handle axis HA to provide further magnetic attraction to the drill bit  66  and, in some configurations, to facilitate retaining cutting tip portions  70  of various sizes, diameters, and the like. By way of illustrative example, a cutting tip portion  70  with a diameter that is smaller than the receptacle  268  of the receiver  276  may be retained both axially and laterally by this arrangement of magnets  286 . 
     The configuration of the tip protector  68  depicted in  FIGS. 45-46  employs a handle  266 , a first handle body  270 , a second handle body  272 , and a sleeve  288  which are similar to the configuration of the tip protector  68  described above in connection with  FIGS. 43-44 . However, in this configuration, the receiver  276  comprises one or more resilient tabs  290  which extend inwardly toward the handle axis HA. Here, when the cutting tip portion  70  is inserted into the receptacle  268 , the resilient tabs  290  contact and exert force on the cutting tip portion  70 . Thus, it will be appreciated that this configuration of the tip protector  68  can likewise be employed to releasably attach to cutting tip portions  70  of various sizes, diameters, and the like. 
       FIGS. 7A-7I  sequentially illustrate certain steps involved with attaching the drill bit  66  to the surgical handpiece assembly  22  and then releasing the drill bit  66  from the surgical handpiece assembly  66 .  FIG. 7A  depicts various portions of the surgical handpiece assembly  62  with the drill bit  66  completely removed. 
     In  FIG. 7B , the insertion portion  72  of the drill bit  66  is shown partially inserted into the surgical handpiece assembly  62 . While not depicted in this view, it will be appreciated that inserting the drill bit  66  may advantageously be performed with the tip protector  68  removably attached to the cutting tip portion  70 , such as to permit relative rotation between the drill bit  66  and the handle  266  as described above. Here in  FIG. 7B , the resilient arms  188  are shown extending away from the proximal end  178  of the shank  176  such that the arm ends  200  are disposed axially between the depth cannula  134  and the distal end  254  of the proximal portion  116  of the drive cannula  114 . The resilient arms  188  are shown arranged in the first position P 1 . 
     In  FIG. 7C , the drill bit  66  is advanced further into the surgical handpiece assembly  62  (compare with  FIG. 7B ). Here, the ramp surfaces  230  of the resilient arms  188  are shown abutting against the seat surface  192  of the proximal portion  116  of the drive cannula  114 , deflecting toward the axis AX. 
     In  FIG. 7D , the drill bit  66  is advanced even further into the surgical handpiece assembly  62  (compare with  FIG. 7C ). Here, the outer arm surfaces  222  of the resilient arms  188  are shown in contact with the bore  122  of the proximal portion  116  of the drive cannula  114  which, as will be appreciated from the previous description of the aligning element  242 , means that the interface  124  of the drill bit  66  is indexed relative to the bore  122  of the proximal portion  116  of the drive cannula  114  without any engagement, contact, or abutment occurring between the interface  124  and the bore  122 . Furthermore, the resilient arms  188  are shown arranged in the second position P 2  in  FIG. 7D . 
     In  FIG. 7E , the drill bit  66  is advanced still further into the surgical handpiece assembly  62  (compare with  FIG. 7D ). Here, the proximal interface end  196  of the interface  124  has entered the bore  122  of the proximal portion  116  of the drive cannula  114 . Here too in  FIG. 7E , the resilient arms  188  are shown arranged in the second position P 2 . 
     In  FIG. 7F , the drill bit  66  is advanced fully into the surgical handpiece assembly  62  (compare with  FIG. 7E ). Here, the resilient arms  188  are shown deflected back away from the axis AX, away from the second position P 2  toward (or, in some configurations, at) the first position P 1 . As noted above, this brings the retention surfaces  224  of the resilient arms  188  into abutment with the lock surfaces  262  provided at the proximal end  256  of the proximal portion  116  of the drive cannula  114 , which prevents the drill bit  66  from moving distally along the axis AX. Moreover, abutment between the stop surface  190  of the drill bit  66  and the seat surface  192  of the proximal portion  116  of the drive cannula  114  prevents the drill bit  66  from advancing axially further into the surgical handpiece assembly  62 . Thus, the drill bit  66  is axially locked to the drive cannula  114  in  FIG. 7F . Furthermore, because the interface  124  of the drill bit  66  is disposed within the bore  122  of the proximal portion  116  of the drive cannula  114 , the drill bit  66  is also rotationally locked to the drive cannula  114 . As such, when in the orientation depicted in  FIG. 7F , the surgical handpiece assembly  62  can be utilized to rotate the drill bit  66 . 
     In  FIG. 7G , the drill bit  66  is disposed in the same axial position as is illustrated in  FIG. 7F , but the resilient arms  188  are shown deflecting back toward the axis AX to facilitate removing the drill bit  66  from the surgical handpiece assembly  62  via actuation of the release assembly  150  (compare with  FIG. 7F ). More specifically, in  FIG. 7G , rotation of the collar  162  of the release assembly  150  has resulted in axial translation of the release member  164  to bring the release surface  175  of the actuating element  174  into abutment with the ramp surfaces  230  of the resilient arms  188 , thereby deflecting the resilient arms  188  back toward the axis AX. 
     In  FIG. 7H , the drill bit  66  has been pushed slightly forward (distally) from the axial positions illustrated in  FIGS. 7F-7G  and the resilient arms  188  are shown deflected even further back toward the axis AX (compare with  FIG. 7G ). Here in  FIG. 7H , further rotation of the collar  162  of the release assembly  150  has resulted in additional axial translation of the release member  164 , thereby causing the resilient arms  188  to deflect even further back toward the axis AX to bring the retention surfaces  224  of the resilient arms  188  back out of abutment with the lock surfaces  262  provided at the proximal end  256  of the proximal portion  116  of the drive cannula  114  to facilitate removing the drill bit  66  from the surgical handpiece assembly  62 . 
     In  FIG. 7I , the drill bit  66  is retracted axially after having been released via the release assembly  150  (compare with  FIG. 7H ). Here in  FIG. 7I , the resilient arms  188  are shown arranged in the second position P 2  and are disposed adjacent to the proximal end  256  of the proximal portion  116  of the drive cannula  114 . Here in  FIG. 7I , because the retention surfaces  224  of the resilient arms  188  are out of abutment with the lock surfaces  262  of the proximal portion  116  of the drive cannula  114 , the drill bit  66  can be removed from the surgical handpiece assembly  62 . In some configurations, the potential energy stored in the in the resilient arms  188  when deflected toward the second position P 2  and out of abutment with the lock surfaces  262  will force (i.e. “kick”) the drill bit distally forward from the axial positions shown in  FIGS. 7F-7G . This feature is particularly advantageous as the drill bit  66  may be released via the release assembly  150  by the user with a single hand. In other words, the user need not grasp or otherwise affect movement of the drill bit  66  directly with one hand while operating the release assembly  150  to disengage the drill bit  66  from the drive cannula  114  with the other hand. 
     In this manner, the end effector assembly  64  described herein and illustrated throughout the drawings affords significant advantages in connection with facilitating releasable attachment to surgical handpiece assembly  62 . Specifically, it will be appreciated that the drill bit  66  of the present disclosure can be reliably attached to the surgical handpiece assembly  62  in a simple, efficient manner by guiding the insertion portion  72  into the proximal portion  116  of the drive cannula  114  and then applying force along the axis AX. Moreover, it will be appreciated that the tip protector  68  described herein affords additional advantages when used in connection with the drill bit  66  by allowing the user to safely handle and position the drill bit  66  while guiding the insertion portion  72  into the proximal portion  116  of the drive cannula  114  and applying force along the axis AX. Furthermore, the self-aligning features of the end effector assembly  64  described herein, including without limitation the aligning element  242  of the resilient arms  188  and the relative rotation afforded between the drill bit  66  and the handle  266  of the tip protector  68 , further promote improved user experience and efficient, reliable attachment to the surgical handpiece assembly  62 . 
     As noted above, the distal portion  118  of the drive cannula  114  may comprise the distal protrusion  126 , which is provided to facilitate transmitting rotational torque when the surgical handpiece assembly  62  is utilized in connection with other applications besides rotating the drill bit  66 . More specifically, the illustrated drive cannula  114  is configured such that the surgical handpiece assembly  62  can rotate, drive, or otherwise actuate a number of different types of surgical attachment modules, tools, end effectors, and the like, which can be configured to engage and rotate concurrently with the distal protrusion  126  of the distal portion  118  of the drive cannula  114 . It will be appreciated that this configuration allows the same surgical handpiece assembly  62  to be utilized in a broad number of medical and/or surgical procedure, such as a drill procedure and a reaming procedure, a drill procedure and a sawing procedure, or a drilling procedure and a wire drive procedure. For instance, the distal portion  118  of the drive cannula  114  may be employed to assist in operation of and attachment to one of a sagittal saw assembly, a reciprocating saw assembly, a drill chuck assembly, a reamer assembly, a wire driving assembly, and a burring assembly. 
     As shown in  FIGS. 47-51 , one exemplary surgical attachment module  300  is illustrated being configured for removable attachment to the surgical handpiece assembly  62 .  FIGS. 47 and 48  illustrate the surgical attachment module  300  separated from the surgical handpiece assembly  62 . The handpiece housing assembly  74  comprises a handpiece coupler  302  adjacent a distal region of the housing assembly  74 . The surgical attachment module  300  comprises a surgical attachment housing  304 . The surgical attachment housing  304  may comprise a surgical attachment coupler  306  that is configured to be removably coupled to the handpiece coupler  302 . In the illustrated configurations, the handpiece coupler  302  and the surgical attachment coupler  306  cooperate to form a bayonet coupling. The surgical attachment coupler  306  comprises a bayonet mount  308  and the handpiece coupler  302  defines a cavity  310  configured to receive the bayonet mount  308  or vice-versa. The surgical handpiece assembly  62  comprises a pin  312  coupled to a spring biased button  314  (See  FIGS. 50-51 ) to engage with the bayonet mount  308  in the cavity  310  of the surgical handpiece assembly  62  to releasably attach the surgical attachment module  300  to the surgical handpiece assembly  62 . More specifically, the bayonet mount  308  may comprise a non-linear slot  316  (See  FIG. 48 ) such as a “J-slot” configured to receive the pin  312 . When the button  314  is depressed, the pin  312  moves to a position to be received by the slot  316  of the bayonet mount  308 . When the bayonet mount  308  is received in the cavity  310 , the button  314  may be released to permit the pin  312  into a seat of the slot  316  for securing the bayonet mount  308  in the cavity  310  of the surgical handpiece assembly  62 . In some configurations, the slot  316  is formed with a ramped surface to bias the pin  312  and apply force in opposition to the spring biased button  314  to guide the pin  312  into the slot  316  without the user depressing the button  314 . When the pin  312  is in the seat of the slot  316 , the bayonet mount  308 , and thus the surgical attachment module  300  is in an engaged position coupled to the surgical handpiece assembly  62  and axial movement of the bayonet mount  308  and the surgical attachment housing  304  is prevented. To disengage the bayonet mount  308  from the handpiece coupler  302 , the user depresses the button  314  to unseat the pin  312  from the seat of the slot  316  to permit the surgical attachment housing  304  to be moved axially away from the handpiece coupler  302 . It is contemplated that the handpiece coupler  302  and the surgical attachment coupler  306  could have different arrangements or geometries so long as the handpiece coupler  302  and the surgical attachment coupler  306  cooperate to attach to one another. In other configurations, a bushing of the surgical attachment module  300  includes the bayonet mount described above. 
     As shown in  FIG. 49 , the surgical attachment module  300  is in the engaged position. The surgical attachment module  300  comprises a drive shaft  318  that is rotatably coupled to the surgical attachment housing  304  and configured to rotate about a surgical attachment axis SX. The surgical attachment axis SX is aligned with the axis AX of the surgical handpiece assembly  62  when the surgical attachment module  300  is in the engaged position. When the surgical attachment module  300  is in the engaged position, the drive shaft  318  of the surgical attachment module  300  is coupled to the distal protrusion  126  and the surgical attachment module  300  is configured to receive torque from the distal protrusion  126  of the drive cannula  114 . The drive shaft  318  comprises a protrusion  320  configured to couple to the distal protrusion  126  and receive torque from the distal protrusion  126  via interference coupling. It is contemplated that the drive shaft  318  could have a different arrangement or geometry so long as the drive shaft  318  engages with the distal protrusion  126  to receive torque from the distal protrusion  126 . Again, while a particular geometry is described throughout this application for the drive shaft  318  and the drive cannula  114 , it should be appreciated that each component may have any suitable configuration that is sufficient to transmit torque from the drive cannula  114  to the surgical attachment module  300 . In the illustrated configuration, the surgical attachment module  300  comprises an output member configured to drive a surgical end effector. A linkage and/or a gear train may be coupled to the drive shaft  318  and the output member to convert torque received from the distal protrusion  126  and available at the drive shaft  318  to mechanical power available at the output member for driving the surgical end effector. 
     As shown in  FIGS. 47 and 50-51 , the surgical handpiece assembly  62  comprises one or more electrical connectors  322  coupled to the power source when the surgical handpiece assembly  62  is coupled to the power source (e.g., removable battery). While the surgical attachment module  300  described above only receives mechanical power and does not receive electrical power, it is contemplated that one or more surgical attachment modules may receive both mechanical power and electrical power from the surgical handpiece assembly  62 . For instance, another surgical attachment module (not illustrated) may comprise a rotary drive attachment module that comprises a light source (not shown) such that the rotary drive attachment module is configured to receive mechanical power in the form of torque through a drive shaft  318  and electrical power in the form of voltage through the electrical connections of the surgical handpiece assembly  62 . In other configurations, certain surgical attachment modules may receive exclusively electrical power from the surgical handpiece when coupled thereto. 
     In  FIGS. 47-51 , the surgical attachment module  300  comprises a wire driver assembly. One such wire driver assembly is disclosed in U.S. Patent Publication No. 2017/0340374 entitled “Surgical Wire Driver Capable of Automatically Adjusting for the Diameter of the Wire or Pin Being Driven” and filed on May 15, 2017, which is hereby incorporated by reference in its entirety. It is contemplated that other surgical attachment modules having a surgical attachment coupler configured to be coupled to the handpiece coupler  302  of the surgical handpiece assembly  62  and configured to receive torque from the distal protrusion  126  of the distal portion  118  of the drive cannula  114  may also be removably attached to the surgical handpiece assembly  62 . 
     As noted above, the surgical handpiece system  60  further comprises the measurement module  128 , which is configured to releasably attach to the surgical handpiece assembly  62  to provide the surgeon with measurement functionality associated with the surgical handpiece assembly  62 . This measurement module  128  can be used with the surgical handpiece assembly when the drill bit  66  is engaged with the proximal portion  116  of the drive cannula  114 . The depth cannula  134  is disposed within the guide bushing  132  and is supported for translational movement along the measurement axis MX. The depth cannula  134  is at least partially disposed within the measurement housing  138 . Similar to the surgical attachment module  300 , the measurement module  126  comprises a measurement coupler  324 ,  326  that is configured to be removably coupled to the handpiece coupler  302 . In some configurations (see  FIGS. 52-54 ), the housing  138  comprises the measurement coupler  324 . In other configurations (see  FIGS. 55-66 ), the bushing  132  comprises the measurement coupler  326 . In the illustrated configurations, the handpiece coupler  302  and the measurement coupler  324 ,  326  cooperate to form a bayonet coupling. The measurement coupler  324 ,  326  comprises a bayonet mount  328 ,  330  and the cavity  310  of the handpiece coupler  302  is configured to receive the bayonet mount  328 ,  330  or vice-versa. The pin  312  coupled to the spring biased button  314  (See  FIGS. 50 and 54 ) is configured to engage with the bayonet mount  328 ,  330  in the cavity  310  of the surgical handpiece assembly  62  to releasably attach the measurement module  128  to the surgical handpiece assembly  62 . More specifically, the bayonet mount  328 ,  330  may comprise a non-linear slot  332 ,  334  (See  FIGS. 53, 56, and 64 ) such as a “J-slot” configured to receive the pin  312 . When the button  314  is depressed, the pin  312  moves to a position to be received by the slot  332 ,  334  of the bayonet mount  328 ,  330 . When the bayonet mount  328 ,  330  is received in the cavity  310 , the button  314  may be released to permit the pin  312  to move into a seat of the slot  332 ,  334  for securing the bayonet mount  328 ,  330  in the cavity  310  of the surgical handpiece assembly  62 . In some configurations, the slot  332 ,  334  is formed with a ramped surface to bias the pin  312  and apply force in opposition to the spring biased button  314  to guide the pin  312  into the slot  332 ,  334  without the user depressing the button  314 . When the pin  312  is in the seat of the slot  332 ,  334 , the bayonet mount  328 ,  330 , and thus the measurement module  128  is in an engaged position coupled to the surgical handpiece assembly  62  and axial movement of the bayonet mount  328 ,  330  and the measurement housing  138  is prevented. To disengage the bayonet mount  328 ,  330  from the handpiece coupler  302 , the user depresses the button  314  to unseat the pin  312  from the seat of the slot  332 ,  334  to permit the measurement module  128  to be moved axially away from the handpiece coupler  302 . It is contemplated that the handpiece coupler  302  and the measurement coupler  324 ,  326  could have different arrangements or geometries so long as the handpiece coupler  302  and the measurement coupler  324 ,  326  cooperate to attach to one another. The surgical handpiece system  60  presents an advantage in employing the same handpiece coupler  302  to interchangeably attach both the surgical attachment module  300  (attachment that receives mechanical power from the surgical handpiece assembly  62 ) and a measurement module  128  to the surgical handpiece assembly  62  (attachment that does not receive mechanical power from the surgical handpiece assembly  62 ) without having to buy two surgical handpieces—one dedicated to the measurement function and others dedicated to cutting/drilling tissue. 
     As best shown in  FIGS. 4 and 6 , the depth cannula  134  comprises an internal surface defining a bore  338 . The bore  338  of the depth cannula  134  is sized to at least partially receive the drill bit  66  when the measurement coupler is attached to the handpiece coupler  302 . The depth cannula  134  is configured to slide relative to the drill bit  66  to assist in performing measurement functions associated with the surgical handpiece assembly  62 . In certain configurations, the drive cannula  114 , the depth cannula  134 , and the drill bit  66  are arranged to be concentric when the drill bit  66  is in the engaged position and the measurement module  128  is coupled to the surgical handpiece assembly  62 . The depth cannula  134  is sized to be at least partially received within the bore  122  of the distal portion  118  of the drive cannula  114  when the drill bit  66  is in the engaged position and the measurement housing  138  is coupled to the handpiece housing assembly  74 . The concentricity of the depth cannula  134  to the drill bit  66  along the measurement axis MX and the axis of the handpiece AX and the arrangement of the depth cannula  134  configured to be received in the drive cannula  114 , which is situated in the surgical handpiece assembly  62 , is beneficial in providing increased visibility of a surgical site to a user operating the surgical system  60  with the measurement module  128 . The construction of the surgical handpiece described in International Patent Publ. No. WO 2017/040783 (Application No. PCT/US2016/049899) entitled “Powered Surgical Drill with Integral Depth Gauge That Includes a Probe That Slides Over the Drill Bit” filed on Jan. 9, 2016, which is hereby incorporated by reference for all that it discloses. In certain embodiments, the depth cannula  134  may comprise a depth extension that is not concentric with the bore of the drive cannula  114 . 
       FIGS. 52-54  show the surgical handpiece system  60  in accordance with an exemplary configuration of the measurement module  128 . In at least some respects, the configuration shown in  FIGS. 52-54  is the same as the configuration previously described with like numbers indicating like components. In the configurations shown in  FIGS. 52-54 , the measurement housing  138  comprises the measurement coupler  324  as described below. It should be appreciated that any features that are described in  FIGS. 47-51  may be included in the embodiment described in  FIGS. 52-54  and vice-versa. 
     As shown in  FIG. 53 , the measurement housing  138  comprises a body portion  340  having a proximal region with a proximal surface  342  configured to face the surgical handpiece assembly  62  when the measurement module  128  is coupled to the surgical handpiece assembly  62 . The measurement housing  138  may comprise any suitable material, such as plastic or metal. Additionally, the measurement housing  138  may be formed from two complementary shell components. 
     The measurement housing  138  comprises the measurement coupler  324 . The measurement coupler  324  extends proximally from the proximal surface  342 . As noted above and illustrated in the configuration shown in  FIG. 53 , the measurement coupler  324  comprises the bayonet mount  328 . The bayonet mount  328  comprises the “J-slot”  332  as described above and another slot  344  opposite the “J-slot” for receiving a projection  346  of the motor housing  85  (See  FIG. 50 ) to assist in radial alignment relative to the handpiece coupler  302 . 
     As shown in  FIG. 54 , the measurement module  128  also comprises the bushing  132  at least partially received in the measurement housing  138  and at least partially surrounding the depth cannula  134  between a proximal end and a distal end of the bushing  132 . The proximal end of the bushing  132  extends beyond the proximal surface  342  of the measurement housing  138  in certain configurations. In some configurations where a bayonet mount  328  is employed such as those illustrated in  FIGS. 53 and 54 , the bayonet mount  328  comprises a bore  348  and the bushing  132  extends through the proximal surface  342  of the measurement housing  138  within the bore  348  of the bayonet mount  328 . The bushing  132  comprises an internal surface defining a bore  350 . The bore  350  of the bushing  132  is concentric to the measurement axis MX, with the bore  350  of the bushing  132  surrounding the depth cannula  134 . The bushing  132  is configured to be partially received by the bore  352  of the distal portion  118  of the drive cannula  114  when the measurement coupler  324  is attached to the handpiece coupler  302 . The bushing  132  also comprises an external surface having an alignment portion  354  adjacent the proximal end of the bushing  132 . 
     The alignment portion  354  of the bushing  132  has an outer diameter sized to approximate an inner diameter of the bore  352  of the distal portion  118  of the drive cannula  114  to align the measurement axis MX to the axis AX of the handpiece. In other words, the alignment portion  354  functions to pilot the bushing  132  into the bore  352  of the distal portion  118  of the drive cannula  114 . In some configurations, the alignment portion  354  tapers toward the measurement axis MX distally to proximally to assist in alignment. Ensuring proper alignment of the measurement axis MX to the axis AX of the handpiece, i.e., axis of the drive cannula  114 , mitigates binding that may otherwise occur between the depth cannula  134 , the drive cannula  114 , and the drill bit  66  when the measurement module  128  is coupled to the surgical handpiece assembly  62 . Binding may be defined as undesired friction between the depth cannula  134  and at least one of the drive cannula  114  and drill bit  66  that may result in restriction of axial movement of the depth cannula  114  relative to the drive cannula  114  and the drill bit  66  along the measurement axis MX. This binding may impede prompt distal movement of the depth cannula  134  when the drill bit  66  is retracted. More specifically, if the binding forces are too great, then a biasing mechanism (described below) associated with the depth cannula  134  may not be able to cause the depth cannula  134  to maintain engagement with the bone surface or plate surface, and a controller of the measurement module  128  may not be able to accurately determine acceleration, positive or negative, of the depth cannula  134  when the surgical handpiece assembly  62  is moved proximally. Aligning the bushing  132  directly to the drive cannula  114  creates a part-to-part alignment. One benefit of using part-to-part alignment is mitigating misalignment that could be attributable to a tolerance stack-up. 
     As shown in  FIG. 53 , the measurement housing  138  may comprise an electrical connector  356  configured to engage the electrical connector  322  of the surgical handpiece assembly  62  to transmit electrical power between the surgical handpiece assembly  62  and the measurement module  128  when the handpiece coupler  302  is coupled to the measurement coupler  324 . In the configuration illustrated in  FIG. 53 , the electrical connector  356  of the measurement module  128  comprises two or three electrical pins and the electrical connector  322  of the surgical handpiece assembly  62  comprises two or three corresponding pin receptacles configured to receive the electrical pins when the measurement module  128  is coupled to the surgical handpiece assembly  62 . The three electrical pins extend from the proximal surface  342  of the body portion  340  of the measurement housing  138  and are spaced radially from the bushing. More specifically, the group of three electrical pins is arranged to be spaced from the slots  332 ,  344  of the bayonet mount  328  at radially equal distances between the slots  332 ,  344 . The three electrical pins comprise an electrical pin for power, an electrical pin for ground, and an electrical pin for data signal transfer. The electrical pin for signal transfer could be used for communication and control between the measurement module  128  and the surgical handpiece assembly  62 . In some configurations electrical connector  356  of the measurement module  128  and the electrical connector  322  of surgical handpiece assembly  62  comprise fewer than three pins and pin receptacles, respectively. In other configurations, the measurement module  128  and surgical handpiece assembly  62  comprise more or fewer than three pins and pin receptacles, respectively. The electrical connector  356  of the measurement module  128  are configured to receive electrical power from the surgical handpiece assembly  62 . The electrical connector  356  of the measurement module  128  are also coupled to the displacement sensor assembly  136  and the display  148  to supply electrical power to the displacement sensor assembly  136  and the display  148  when the measurement coupler  324  is coupled to the surgical handpiece assembly  62 . 
       FIGS. 55-66  show the surgical handpiece system  60  in accordance with another exemplary configuration of the measurement module  128 . In at least some respects the configuration shown in  FIGS. 55-66  is the same as the configuration previously described with like numbers indicating like components. In the configurations shown in  FIGS. 55-66 , the bushing  132  comprises the measurement coupler  326  as described below. Again, any of the features described above with respect to the other embodiments of the measurement module  128  can be used in conjunction with the instant embodiment, and vice-versa. For example, the structure of the electrical connectors  322 ,  356  described above can be used with any construction of the measurement module  128 . 
     As shown in  FIG. 56 , the measurement housing  138  comprises the body portion  340  having a proximal region with a proximal surface  342  configured to face the surgical handpiece assembly  62  when the measurement module  128  is coupled to the surgical handpiece assembly  62 . 
     As shown in  FIG. 57 , the measurement module  128  comprises the bushing  132  partially received in the measurement housing  138 . The bushing  132  extends along the measurement axis MX between a proximal end protruding beyond the proximal surface  342  of the measurement housing  138  and a distal end opposite the proximal end. The bushing  132  comprises a proximal portion  358  adjacent the proximal end comprising a bore  360  having a first inner diameter. In the configuration shown in  FIG. 57 , the proximal portion  358  of the bushing  132  comprises the measurement coupler  326 . As noted above and illustrated in the configuration shown in  FIG. 57 , the measurement coupler  326  may comprise the bayonet mount  330 . The bayonet mount  330  comprises the “J-slot”  334  as described above and another slot  362  opposite the “J-slot” for receiving a projection  364  of the motor housing  85  (see  FIG. 60 ) to assist in radial alignment relative to the handpiece coupler  302 . 
     The proximal portion  358  of the bushing  132  is configured to abut the motor housing  85  (See  FIGS. 50 and 51 ). The proximal portion  358  of the bushing  132  abuts the motor housing  85  to assist in alignment of the measurement axis MX to the handpiece axis AX. The alignment of the measurement axis MX to the axis AX of the handpiece mitigates binding that may otherwise occur between the depth cannula  134 , the drive cannula  114 , and the drill bit  66  when the measurement module  128  is coupled to the surgical handpiece assembly  62  and during axial movement of the depth cannula  134  during the surgical procedure. The bushing  132  also comprises a distal portion  366  between the proximal portion  358  and the distal end comprising a bore  368  in communication with the bore  360  of the proximal portion  358 . The bore  368  of the distal portion  366  has a second inner diameter smaller than the first inner diameter. The bore  368  of the distal portion  366  is sized to approximate an outer diameter of the external surface of the depth cannula  134  to assist in keeping the depth cannula  114  concentric to the bushing  132  and the measurement axis MX. 
     As best shown in  FIGS. 60 and 64 , the proximal portion  358  of the bushing  132  may define one or more recesses  370  in communication with the bore  360  of the proximal portion  358  of the bushing  132 . The one or more recesses  370  are each configured to receive a portion of the motor housing  85  to assist in radially aligning the bushing  132  relative to the surgical handpiece assembly  62  and to ensure alignment of the measurement axis MX to the axis AX of the handpiece. In the illustrated configuration, the proximal portion  358  of the bushing  132  defines four recesses  370 . 
     In one configuration shown in  FIGS. 58, 59, and 66 , at least one of the distal portion  366  of the bushing  132  and the depth cannula  134  comprises one or more protrusions extending toward the other of the distal portion  366  of the bushing  132  and the depth cannula  134 . The one or more protrusions are configured to assist in centering the depth cannula  134  in the bore  368  of the distal portion  366  of the bushing  132  and within the bore  352  of the distal portion  118  of the drive cannula  114  of the surgical handpiece assembly  62 . In some configurations, the one or more protrusions may each comprise an annular ring. In other configurations, the one or more protrusions  372  comprise individual protrusions  376  radially arranged about the bushing  132  (see  FIG. 66 ). Although the one or more protrusions  372  are illustrated at the distal end portion of the bushing  132 , it is contemplated that the one or more protrusions  372  may be arranged at another location along the bushing  132 . For instance, the one or more protrusions  372  may be located directly beneath the gear  146  of the measurement module  128  to assist in retaining a consistent and tight meshing engagement of the gear  146  to the plurality of teeth of the depth cannula  134  when the depth cannula  134  moves along the measurement axis MX. The protrusions  372  may take the form of two, three or more axially extending ribs spaced apart in the bushing  132  to surround the depth cannula  134 . In certain embodiments, the protrusions  372  on the bushing  132  are spaced such that they do not interact with the teeth of the depth cannula  134 . 
     The depth cannula  134  may also comprise one or more protrusions  373  extending outwardly from the external surface of the depth cannula  134 . The one or more protrusions  373  are configured to abut at least one of the bushing  132  and the drive cannula  114  to center the depth cannula  134  in the bores  360 ,  368  of the bushing  132 , which results in the depth cannula  134  being centered in the bore  352  of the drive cannula  114 . In one configuration shown in  FIG. 59 , the one or more protrusions  373  extending outwardly from the external surface of the depth cannula  134  comprises an annular ring  374 . In the configuration illustrated in  FIGS. 55-66 , the one or more protrusions  373  extending outwardly from the external surface of the depth cannula  134  are configured to cooperate with the one or more protrusions  372  extending into the bore  368  of the bushing  132  to assist in centering the depth cannula  134  in the bore  368  of the bushing  132  and within the bore  352  of the drive cannula  114 . Centering the depth cannula  134  in the bore  352  of the bushing  132  and the bore  352  of the drive cannula  114  assists in mitigating binding between the depth cannula  134 , the drive cannula  114 , and the drill bit  66  when the measurement coupler  326  is coupled to the handpiece housing assembly  74 . It is particularly advantageous to use two sets of protrusions (a set of protrusions on the bushing  132  and a set of protrusions on the depth cannula  134 ) as described above to limit hinging that may occur with only one set of protrusions. The protrusions  372 ,  373  may have any suitable shape or size. The number of protrusions may vary, such as 1, 2, 3, 4 or more. The protrusions  372 ,  373  are sized and positioned such that the depth cannula  134  may move within the bore  368  of the bushing  132  without binding. In addition, it is contemplated that the depth cannula  134  may have two sets of protrusions, one set spaced apart axially from the other set. Similarly, it is contemplated that the bushing  132  may have two sets of protrusions, one set spaced apart axially from the other set. 
     As shown in  FIGS. 62-63 , the measurement module  128  comprises a biasing mechanism  378  coupled to the gear  146  and configured to bias the gear  146  to rotate in one direction such that the proximal end of the depth cannula  134  is biased to a biased position toward the distal end of the bushing  132 . In the illustrated configuration, the biasing mechanism  378  comprises a torsion spring. The biasing mechanism  378  assists the displacement sensor assembly  136  to generate accurate signals for measurement functions associated with the depth cannula  134 . Consistent and unrestricted (no binding) movement of the depth cannula  134  assists in proper operation of the biasing mechanism  378 . More specifically, if the biasing mechanism  378  fails in properly returning the depth cannula  134  to the biased position of the depth cannula  134  during a surgical operation, the resulting signal may reflect an accurate position of the depth cannula  134 , but the position of the depth cannula  134  may be in an incorrect position for the surgical operation as a result of binding. 
     It should be appreciated that the depth cannula  134 , in certain embodiments, is freely movable relative to the measurement housing  138  and the surgical handpiece assembly  62  and does not act to limit the depth of drilling. In other words, the depth cannula  134  may not act as a drill stop and is not coupled to any actuator that positively controls how far the position of the depth cannula  134  is relative to the bone or plate. In other words, the depth cannula  134  may function solely to provide measurement functionality of the bore hole ultimately drilled, but not prevent the user from plunging too far. 
     As shown in  FIGS. 56, 61, and 64  the measurement housing  138  comprises an electrical connector  380  configured to engage the electrical connector  322  of the surgical handpiece assembly  62  (See  FIGS. 55, 60, and 61 ) to transmit electrical power between the surgical handpiece assembly  62  and the measurement module  128  when the handpiece coupler  302  is coupled to the measurement coupler  326 . In the configuration illustrated in  FIGS. 56, 61, and 64 , the electrical connector  380  of the measurement module  128  comprises three electrical terminals  382  and the electrical connector  322  of the surgical handpiece assembly  62  comprises three corresponding terminal contacts  384  configured to be in electrical contact when the measurement module  128  is coupled to the surgical handpiece assembly  62 . In the illustrated configuration, the electrical terminals  382  are formed to be biased outwardly such that when the electrical terminals  382  engage (see  FIG. 61 ) with the terminal contacts  384 , the terminal contacts  384  apply force in opposition to the biased terminals  382  to assist in proper engagement of the terminals  382  to the terminal contacts  384 . The three electrical terminals  382  extend from the proximal surface  342  of the body portion  340  of the measurement housing  138  and are spaced radially away from the bushing  132  relative to the measurement axis MX. More specifically, the group of three electrical terminals  382  is arranged to be spaced from the slots  334 ,  362  of the bayonet mount  330  at radially equal distances between the slots  334 ,  362 . The three electrical terminals  382  comprise an electrical terminal for power, an electrical terminal for ground, and an electrical terminal for signal transfer. The electrical terminal for signal transfer may be used for communication and control between the measurement module  128  and the surgical handpiece assembly  62 . In some configurations the measurement module  128  and the surgical handpiece assembly  62  comprise fewer than three terminals and terminal contacts, respectively. In other configurations, the measurement module  128  and surgical handpiece assembly  62  comprise more than three terminals and terminal contacts, respectively. The electrical connector  380  of the measurement housing  138  is configured to receive electrical power from the surgical handpiece assembly  62 . The electrical connector of the measurement housing  138  is also coupled to the displacement sensor assembly  136  and the display  148  to supply electrical power to the displacement sensor assembly  136  and the display  148  when the measurement coupler  326  is coupled to the surgical handpiece assembly  62 . 
     It should be appreciated that the protrusions, such as those described in  FIGS. 58, 59, and 66 , may be used with any of the other embodiments of the measurement module described. Additionally, it should be appreciated that any of the embodiments of the measurement module  128  may be used with any version of the surgical handpiece assembly  62  described throughout. 
     A method of reprocessing the depth measurement module for reuse is also contemplated. This method may include obtaining a measurement module that has previously been used. This use may include use during a surgical procedure such that the used measurement module previously contacted a patient. During use of the measurement module, one or more components of the measurement module may become soiled such that the used measurement module is no longer in a sterile condition. The term soiled relates to a component that has any residual biologic material disposed thereon. In certain embodiments, the gear and the plurality of teeth on the depth cannula may be soiled, i.e., have residual biologic material disposed thereon. The used measurement module may include any combination of components described above for the various embodiments of the measurement module described above. Any of the components of the measurement module may become soiled. 
     The method of reprocessing may further include dismantling at least two components of the measurement module from one another. The at least two components may be any component of the measurement module, such as the depth cannula, the gear, the measurement housing, the bushing, the display, etc. The step of dismantling may include separating the measurement housing from the depth cannula and the gear. The step of dismantling may include separating the depth cannula from the gear. The step of dismantling may include separating the bushing from the measurement housing. The step of dismantling may include breaking the measurement housing with a cutting step or breaking a joint step to separate the measurement housing into two components when the two components of the housing were secured to one another using welding or gluing. It should be appreciated that any of these dismantling steps may be performed alone or in combination, depending on the degree to which the measurement module is soiled. 
     Once the step of dismantling is complete, the method may include one or more cleaning steps. One potential cleaning step is to clean the soiled depth cannula. Another potential cleaning step is to clean the soiled gear. Another potential cleaning step is to clean the measurement housing. Yet another potential cleaning step is to clean the display. Additionally, the reprocessing method may include cleaning the bushing and/or the measurement coupler located on the measurement housing or the bushing. It should be appreciated one or more cleaning steps may also be performed before one or more steps of dismantling. 
     The type of cleaning for each component of the measurement module is not particularly limited, and may include mechanical cleaning steps and chemical cleaning steps. For example, the cleaning steps may include subjecting the component to be cleaned to an enzymatic cleaning process, an ultrasonic cleaning process, or a combination thereof. The depth cannula, bushing, and or the gear may be submerged during one or more cleaning steps. The step(s) of cleaning may comprise removing tissue from within the teeth of the depth cannula, from within teeth of the gear, or combinations thereof. Certain components may not be able to withstand aggressive cleaning steps, such as the display or the controller. For these components, the cleaning may include wiping the surface with a cleansing antibacterial wipe that may be alcohol-based. It should be appreciated that any of these steps may be performed alone or in combination, depending on the degree to which the measurement module is soiled. 
     The reprocessing method may further include a step of reassembling the measurement module. If one or more components of the used measurement module are not able to be effectively cleaned, are damaged during use, are damaged during one or more of the dismantling steps, or cannot be used for other reasons, the measurement module may be reassembled with one or more new components. The new components that can be used during the steps of reassembling are not particularly limited, exemplary new components may include a new depth cannula, a new gear, a new bushing, a new displacement sensor assembly, a new measurement housing, a new controller, a new display, or combinations thereof. In certain instances, one or more of the new components may be reassembled with one or more of the cleaned components. 
     For example, the step of reassembling may include reassembling the measurement module with one of the cleaned gear and the cleaned depth cannula. Alternatively, the step of reassembling the measurement module with both the cleaned depth measurement cannula and the cleaned gear. The step of reassembling may alternatively include reassembling the measurement module with a new measurement housing, such as with two or more components that cooperate to form the new measurement housing. The step of reassembling may further include reassembling the measurement module with the new display. The step of reassembling may alternatively include reassembling the measurement module with the cleaned bushing. The step of reassembling may alternatively include reassembling the measurement module with the new bushing. It is contemplated that during the step of reassembling that the new or cleaned depth cannula is placed into a meshing relationship with the new or used gear. It is also contemplated that the new or cleaned housing is reassembled such that the new or cleaned housing at least partially surrounds the new or cleaned gear and the new or cleaned depth cannula. The step of reassembling may include gluing or welding the components of the new or used measurement housing to one another. The step of reassembling may further include the step of securing the bushing to the measurement housing. 
     The method of reprocessing may further include the step of sterilizing the reassembled measurement module. The type of sterilization is not particularly limited, but in certain cases may include sterilizing the reassembled measurement module with the use of ethylene oxide gas. Other types of sterilizing may be used, such as autoclaving sterilization processes or gamma sterilization processes. While in certain embodiments, the measurement module is sterilized after it has been reassembled, it is contemplated that the components measurement module may be sterilized before reassembly as well. 
     It should be noted that in many of the figures described herein, certain components of the surgical handpiece system  60  have been removed for convenience of description and ease of illustration. 
     It should also be noted that while the surgical handpiece system is directed to surgical applications, the surgical handpiece system could be employed for non-surgical applications. 
     It will be further appreciated that the terms “include,” “includes,” and “including” have the same meaning as the terms “comprise,” “comprises,” and “comprising.” Moreover, it will be appreciated that terms such as “first,” “second,” “third,” and the like are used herein to differentiate certain structural features and components for the non-limiting, illustrative purposes of clarity and consistency. 
     Several configurations have been discussed in the foregoing description. However, the configurations discussed herein are not intended to be exhaustive or limit the invention to any particular form. The terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the invention may be practiced otherwise than as specifically described. 
     The invention is intended to be defined in the independent claims, with specific features laid out in the dependent claims, wherein the subject matter of a claim dependent from one independent claim can also be implemented in connection with another independent claim. 
     The present disclosure also comprises the following clauses, with specific features laid out in dependent clauses, that may specifically be implemented as described in greater detail with reference to the configurations and drawings above. 
     I. A drill bit for releasably attaching to a drive assembly of a surgical instrument, the drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising an outermost drive portion spaced from the axis at a first interface distance, the outermost drive portion comprising an outer drive surface facing away from the axis; 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance.       

     II. The drill bit as set forth in clause I, wherein the second arm distance is less than or equal to the first interface distance. 
     III. The drill bit as set forth in any one of clauses I-II, wherein the outer arm surface of the resilient arm and the outer drive surface of the outermost drive portion of the interface are each separately spaced from the axis at substantially the same distance when the resilient arm is in the second position. 
     IV. The drill bit as set forth in any one of clauses I-III, wherein the interface has a generally polygonal profile. 
     V. The drill bit as set forth in clause IV, wherein the interface has a rounded hexagonal profile. 
     VI. The drill bit as set forth in any one of clauses I-V, wherein the resilient arm further comprises an aligning element at the arm end configured to promote at least partial rotation of the drill bit about the axis as the resilient arm moves from the first position to the second position. 
     VII. The drill bit as set forth in clause VI, wherein the aligning element of the resilient arm at least partially comprises the outer arm surface. 
     VIII. The drill bit as set forth in any one of clauses VI-VII, wherein the aligning element of the resilient arm comprises a pair of planar arm surfaces adjacent to the outer arm surface; 
     wherein the interface comprises a pair of planar surfaces; and 
     wherein one of the planar arm surfaces is generally coplanar with one of the planar surfaces when the resilient arm is in the second position. 
     IX. An end effector assembly for releasably attaching to a drive assembly of a surgical instrument, the end effector assembly comprising: 
     a drill bit extending along an axis between a cutting tip portion and an insertion portion; and 
     a tip protector comprising a handle with a handle bore extending along a handle axis, and a receiver rotatably supported within the handle bore and constrained from translating along the handle axis relative to the handle, the receiver defining a receptacle capable of receiving the cutting tip portion of the drill bit; 
     wherein the handle is adapted to be gripped by a user to facilitate attaching the drill bit to the surgical instrument such that the drill bit and the receiver rotate concurrently relative to the handle. 
     X. The end effector assembly as set forth in clause IX, wherein the insertion portion of the drill bit comprises: 
     a shank extending along the axis between a proximal end and a distal end, with the cutting tip portion arranged adjacent to the distal end; 
     an interface arranged between the proximal end and the distal end, the interface comprising an outermost drive portion spaced from the axis at a first interface distance; and 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance; and   wherein the resilient arm further comprises an aligning element at the arm end configured to promote at least partial rotation of the drill bit about the axis as the resilient arm moves from the first position to the second position in response to force applied to the handle as the drill bit end effector assembly is attached to the surgical instrument.       

     XI. The end effector assembly as set forth in any one of clauses IX-X, wherein at least a portion of the tip protector is resiliently deformable. 
     XII. The end effector assembly as set forth in any one of clauses IX-XI, wherein the receiver is configured to receive drill bit cutting tip portions of different sizes. 
     XIII The end effector assembly as set forth in any one of clauses IX-XII, wherein the drill bit is formed from a ferromagnetic material; and wherein the tip protector further comprises a magnet capable of holding the cutting tip portion of the drill bit within the receiver. 
     XIV. An end effector assembly for releasably attaching to a drive assembly of a surgical instrument, the end effector assembly comprising: 
     a drill bit extending along an axis between a cutting tip portion and an insertion portion; and 
     a tip protector removably coupled to the cutting tip portion of the drill bit for allowing a user to handle the drill bit without contacting the cutting tip portion. 
     XV. A method for mounting a drill bit on a surgical instrument having a drive assembly, the drill bit having an insertion portion and a cutting tip portion removably coupled to a tip protector, the method comprising: 
     grasping the tip protector; and 
     inserting the insertion portion of the drill bit into the surgical instrument such that the drill bit rotates relative to at least a portion of the tip protector when the drill bit is coupled to the drive assembly. 
     XVI. The method as set forth in clause XV, wherein the step of inserting the insertion portion of the drill bit into the surgical instrument comprises rotating a receiver of the tip protector holding the cutting tip portion of the drill bit relative to a handle of the tip protector. 
     XVII. The method as set forth in any one of clauses XV-XVI, further comprising axially constraining movement of the drill bit relative to the tip protector. 
     XVIII. A surgical instrument for use with a drill bit extending along an axis and having a retention surface movable from a first position toward the axis to a second position to facilitate releasably attaching the drill bit to the surgical instrument, the surgical instrument comprising: 
     a handpiece body; 
     a drive assembly supported within the handpiece body and comprising a driving cannula configured to axially and rotatably secure the drill bit to the surgical instrument; and 
     a release mechanism configured to facilitate removal of the drill bit from the drive assembly. 
     XIX. The surgical instrument as set forth in clause XVIII, wherein the release mechanism comprises a slide element arranged for axial translation to facilitate removal of the drill bit from the drive assembly. 
     XX. The surgical instrument as set forth in clause XIX, wherein the slide element of the release mechanism further comprises an actuating element shaped to engage a resilient arm of the drill bit to urge the resilient arm at least partially toward the axis. 
     XXI. The surgical instrument as set forth in clause XX, wherein the slide element of the release mechanism further comprises a pocket; and 
     wherein the release mechanism further comprises:
         a spherical guide supported within the pocket of the slide element;   a release body comprising a helical slot extending helically about and along the axis; and   a collar comprising a collar channel facing toward the axis; and       

     wherein the spherical guide rides along the helical slot formed in the release body and translates along the collar channel formed in the collar to facilitate translation of the slide element along the axis in response to rotation of the collar about the axis to facilitate bringing the actuating element into engagement with the resilient arm of the drill bit such that the drill bit can be removed from the surgical instrument. 
     XXII. A drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising a first outermost drive portion and a second outermost drive portion spaced from one another to define a maximum drive dimension of the interface, with the first outermost drive portion spaced from the axis at a first interface distance and the second outermost drive portion spaced from the axis at a second interface distance; and 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, and a retention surface facing toward the distal end of the shank and radially aligned about the axis with one of the first and second outermost drive portions, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance, with the first arm distance greater than the first interface distance when the retention surface is radially aligned with the first outermost drive portion, and the first arm distance greater than the second interface distance when the retention surface is radially aligned with the second outermost drive portion, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance, with the second arm distance less than or equal to the first interface distance when the retention surface is radially aligned with the first outermost drive portion, and the second arm distance less than or equal to the second interface distance when the retention surface is radially aligned with the second outermost drive portion.       

     XXIII The drill bit as set forth in clause XXII, wherein the first interface distance and the second interface distance comprise a common distance at which each of the first outermost drive portion and the second outermost drive portion is spaced from the axis. 
     XXIV. A drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising at least two outermost drive portions spaced from one another to define a maximum drive dimension of the interface with the two outermost drive portions each separately spaced at a first interface distance from the axis; and 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, and a retention surface facing toward the distal end of the shank and radially aligned about the axis with one of the outermost drive portions, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance and less than or equal to the first interface distance.       

     XXV. The drill bit as set forth in clause XXIV, wherein the interface comprises at least four planar surfaces. 
     XXVI. The drill bit as set forth in clause XXV, wherein the interface comprises six planar surfaces. 
     XXVII. The drill bit as set forth in any one of clauses XXIV-XXVI, wherein the interface comprises at least four corners with two of the corners defining the outermost drive portions. 
     XXVIII. The drill bit as set forth in clause XXVII, wherein the interface comprises at least six corners. 
     XXIX. The drill bit as set forth in in any one of clauses XXIV-XXVIII, wherein the interface comprises a plurality of drive lobes with two of the drive lobes defining the outermost drive portions. 
     XXX. The drill bit as set forth in clause XXIX, wherein the plurality of drive lobes comprises four or more drive lobes. 
     XXXI. The drill bit as set forth in clause XXIX, wherein the resilient arm and one of the drive lobes comprise a common bisecting plane intersecting the axis to define two equal portions of the resilient arm and two equal portions of the outermost drive portion. 
     XXXII. The drill bit as set forth in any one of clauses XXIV-XXXI, wherein the resilient arm is further defined as a first resilient arm; and 
     further comprising a second resilient arm extending from the proximal end of the shank to a second arm end, the second resilient arm comprising a second outer arm surface facing away from the axis, and a second retention surface facing toward the distal end of the shank and radially aligned about the axis with one of the outermost drive portions; and 
     wherein the first and second resilient arms are each respectively movable relative to the axis between:
         respective first positions where the respective outer arm surfaces are spaced from the axis at respective first arm distances greater than the first interface distance, and   respective second positions where the respective outer arm surfaces are spaced from the axis at respective second arm distances less than the respective first arm distances and less than or equal to the first interface distance.       

     XXXIII The drill bit as set forth in any one of clauses XXIV-XXXII, wherein the resilient arm extends at least partially away from the axis from the proximal end of the shank to the arm end. 
     XXXIV. The drill bit as set forth in any one of clauses XXIV-XXXIII, wherein the resilient arm comprises a finger portion at the arm end, the finger portion providing the retention surface. 
     XXXV. The drill bit as set forth in clause XXXIV, wherein the finger portion forms a ramp surface configured to deflect the resilient arm toward the axis. 
     XXXVI. The drill bit as set forth in any one of clauses XXIV-XXXV, wherein the interface extends along the axis between a distal interface end and a proximal interface end, with an interface length defined between the distal interface end and the proximal interface end; and 
     wherein the retention surface is spaced from the proximal interface end at a retention distance greater than or equal to the interface length. 
     XXXVII. The drill bit as set forth in any one of clauses XXIV-XXXVI, wherein the interface extends along the axis between a distal interface end and a proximal interface end, with an interface length defined between the distal interface end and the proximal interface end; and 
     wherein the shank has a shank length defined between the distal end and the proximal end, with the shank length being greater than or equal to three times the interface length. 
     XXXVIII. The drill bit as set forth in any one of clauses XXIV-XXXII, wherein the drill bit is cannulated. 
     XXXIX. The drill bit as set forth in any one of clauses XXIV-XXXVIII, wherein the drill bit is a twist drill bit. 
     XXXX. The drill bit as set forth in any one of clauses XXIV-XXXIX, wherein the resilient arm and one of the outermost drive portions are radially positioned within fifteen degrees of one another relative to the axis. 
     XXXXI. The drill bit as set forth in any one of clauses XXIV-XXXXI, wherein the retention surface and one of the outermost drive portions comprise a common bisecting plane intersecting the axis to define two equal portions of the resilient arm and two equal portions of the outermost drive portion. 
     XXXXII. A drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising at least two outermost drive portions spaced from one another to define a maximum drive dimension of the interface with the two outermost drive portions each separately spaced at a first interface distance from the axis; and 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, and a retention surface facing toward the distal end of the shank, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance and less than or equal to the first interface distance;       

     wherein the retention surface comprises a first bisecting plane that intersects the axis to define two equal portions of the retention surface; 
     wherein one of the outermost drive portions comprises a second bisecting plane that intersects the axis to define two equal portions of the outermost drive portion; and 
     wherein the second bisecting plane is radially spaced approximately 60 degrees from the first bisecting plane about the axis. 
     XXXXIII A drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising at least two outermost drive portions spaced from one another to define a maximum drive dimension of the interface with the two outermost drive portions each separately spaced at a first interface distance from the axis, and the interface further comprising at least two outer non-drive portions spaced diametrically from one another relative to the axis to define a minimum interface dimension, the two outer non-drive portions being radially spaced from the two outermost drive portions about the axis; 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, and a retention surface facing toward the distal end of the shank and radially aligned about the axis with one of the outermost drive portions, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance and less than or equal to the first interface distance.       

     XXXXIV. The drill bit as set forth in clause XXXXIII, wherein the interface comprises at least four planar surfaces. 
     XXXXV. The drill bit as set forth in any one of clauses XXXXIII-XXXXIV, wherein the interface comprises at least four corners with two of the corners defining the outermost drive portions. 
     XXXXVI. The drill bit as set forth in any one of clauses XXXXIII-XXXXV, wherein the interface comprises a plurality of drive lobes with two of the drive lobes defining the outermost drive portions. 
     XXXXVII. The drill bit as set forth in clause XXXXVI, wherein the plurality of drive lobes comprises four or more drive lobes. 
     XXXXVIII. The drill bit as set forth in any one of clauses XXXXIII-XXXXVII, wherein the resilient arm is further defined as a first resilient arm; and 
     further comprising a second resilient arm extending from the proximal end of the shank to a second arm end, the second resilient arm comprising a second outer arm surface facing away from the axis, and a second retention surface facing toward the distal end of the shank and radially aligned about the axis with one of the outermost drive portions; and 
     wherein the first and second resilient arms are each respectively movable relative to the axis between:
         respective first positions where the respective outer arm surfaces are spaced from the axis at respective first arm distances greater than the first interface distance, and   respective second positions where the respective outer arm surfaces are spaced from the axis at respective second arm distances less than the respective first arm distances and less than or equal to the first interface distance.       

     XXXXIX. The drill bit as set forth in any one of clauses XXXXIII-XXXXVIII, wherein the resilient arm extends at least partially away from the axis from the proximal end of the shank to the arm end. 
     L. The drill bit as set forth in clause XXXXIX, wherein the resilient arm comprises a finger portion at the arm end, the finger portion providing the retention surface. 
     LI. The drill bit as set forth in clause L, wherein the finger portion forms a ramp surface configured to deflect the resilient arm toward the axis. 
     LII. A drill bit comprising: 
     a shank extending along an axis between a proximal end and a distal end; 
     a cutting tip portion adjacent to the distal end of the shank; 
     an interface arranged between the proximal end and the distal end, the interface comprising at least one outermost drive portion spaced at a first interface distance from the axis; and 
     a resilient arm extending from the proximal end of the shank to an arm end, the resilient arm comprising an outer arm surface facing away from the axis, and a retention surface facing toward the distal end of the shank and radially aligned about the axis with respect to the outermost drive portion at an angle of approximately 0-degrees, 60-degrees, 120-degrees, or 180-degrees, the resilient arm being movable relative to the axis between:
         a first position where the outer arm surface is spaced from the axis at a first arm distance greater than the first interface distance, and   a second position where the outer arm surface is spaced from the axis at a second arm distance less than the first arm distance and less than or equal to the first interface distance.       

     LIII. A method of preparing a depth sensing measurement module for reuse, said method comprising: 
     obtaining a measurement module that has been previously been used, the measurement module including:
         a measurement housing;   a depth cannula movably coupled to said measurement housing, the depth cannula comprising a plurality of teeth disposed linearly along at least a partial length of the depth cannula;   a gear rotatably coupled to the measurement housing, the gear is disposed in a meshing relationship with the plurality of teeth such that rotation of the gear and movement of the depth cannula are directly proportional;   a displacement sensor assembly configured to generate a signal responsive to movement of the gear; and       

     a display coupled to the measurement housing;
         wherein a residual biologic material is disposed on one or more of the plurality of teeth and the gear which results in the depth cannula and the gear being soiled;   dismantling at least two components of the measurement module from one another;   cleaning at least one of the soiled depth cannula and the soiled gear;   reassembling the measurement module with one of the cleaned gear and the cleaned depth cannula; and   sterilizing the reassembled measurement module.       

     LIV. The method of clause LIII, further comprising cleaning both the soiled depth cannula and the soiled gear; 
     reassembling the measurement module with both the cleaned depth measurement cannula and the cleaned gear; and 
     sterilizing the reassembled measurement module. 
     LV. The method of any one of clauses LIII-LIV, wherein the step of dismantling the measurement module comprises separating the measurement housing from the soiled depth cannula and the soiled gear. 
     LVI. The method of any one of clauses LIII-LV, further comprising providing a new depth measurement cannula, and wherein the step of reassembling the measurement module comprises reassembling the measurement module with the cleaned gear and the new depth measurement cannula. 
     LVII. The method in any one of clauses LIII-LVI, further comprising providing a new measurement housing, and wherein the step of reassembling the measurement module comprises reassembling the measurement module with the new measurement housing. 
     LVIII. The method in any one of clauses LIII-LVII, further comprising providing a new display, and wherein the step of reassembling the measurement module comprises reassembling the measurement module with the new display. 
     LIX. The method in any one of clauses LIII-LVIII, wherein the step of cleaning comprises removing tissue from within the teeth of the depth cannula, from within teeth of the gear, or combinations thereof. 
     LX. The method in any one of clauses LIII-LIX, wherein the measurement module that has been previously been used comprises a bushing that at least partially surrounds the used depth cannula, said method further comprising cleaning the bushing; and wherein the step of reassembling further comprises reassembling the measurement module with the cleaned bushing. 
     LXI. The method in any one of clauses LIII-LX, wherein the measurement module that has been previously been used comprises a bushing that at least partially surrounds the used depth cannula, said method further comprising providing a new bushing; and wherein the step of reassembling further comprises reassembling the measurement module with the new bushing. 
     LXII. The method in any one of clauses LIII-LXI, wherein the step of sterilizing includes subjecting the reassembled measurement module to ethylene oxide gas. 
     LXIII. The method in any one of clauses LIII-LXII, wherein the step of cleaning includes subjecting one of the soiled depth cannula and the soiled gear to an enzymatic cleaning process, an ultrasonic cleaning process, or a combination thereof. 
     LXIV. The method in any one of clauses LIII-LXIII, wherein the measurement module that has been previously used comprises a measurement coupler, said method further comprises cleaning the measurement coupler. 
     LXV. A method of preparing a depth sensing measurement module for reuse, said method comprising:
         obtaining a measurement module that has been previously been used, the measurement module including:
           a measurement housing;   a depth cannula movably coupled to said measurement housing, the depth cannula comprising a plurality of teeth disposed linearly along at least a partial length of the depth cannula;   a gear rotatably coupled to the measurement housing, the gear is disposed in a meshing relationship with the plurality of teeth such that rotation of the gear and movement of the depth cannula are directly proportional;   a displacement sensor assembly configured to generate a signal responsive to   
               

     movement of the gear; 
     a display coupled to the measurement housing; 
     wherein a residual biologic material is disposed on one or more of the plurality of teeth and the gear which results in the depth cannula and the gear being soiled; 
     dismantling at least two components of the measurement module from one another; 
     disengaging the teeth of the soiled depth cannula from the soiled gear; 
     reassembling the measurement module with a new depth cannula; and 
     sterilizing the reassembled measurement module. 
     LXVI. A measurement module for facilitating alignment to a surgical handpiece assembly having a handpiece housing assembly supporting a drive cannula and a drill bit, each rotatable about a handpiece axis, with the drill bit extending along the handpiece axis disposed within a bore of the drive cannula, the measurement module comprising:
         a measurement housing comprising a proximal region and a distal region, with the proximal region comprising a proximal surface;   a depth cannula movably coupled to the measurement housing, the depth cannula comprising a proximal end, a distal end, and a length therebetween disposed along a measurement axis, the depth cannula configured to move along the measurement axis relative to the measurement housing through the proximal and distal regions, and the depth cannula comprising,   a bore extending through the proximal and distal ends configured to receive the drill bit,   a bushing partially received in the measurement housing and extending along the measurement axis between a proximal end protruding through the proximal surface of the measurement housing and a distal end adjacent the distal region of the measurement housing, and the bushing comprising,   a bore configured to receive the depth cannula, and   one or more protrusions extending into the bore of the bushing;   a bayonet coupler configured to be removably coupleable to the handpiece housing assembly;   one or more electrical terminals extending from the proximal surface of the measurement housing and spaced from the bushing.   a displacement sensor assembly configured to generate a signal responsive to movement of the depth cannula; and   a display coupled to the measurement housing;       

     LXVII. A measurement module for attachment to a handheld surgical instrument to provide measurement functionality to the handheld surgical instrument, the measurement module comprising:
         a mechanical assembly comprising a detection element configured to move a distance during use of the surgical instrument, the distance being indicative of a procedural parameter; and   a sensor assembly removably coupleable to the mechanical assembly and operatively engageable with the detection element of the mechanical assembly such that the sensor assembly is configured to sense the distance moved by the detection element of the mechanical assembly when the sensor assembly is coupled to the mechanical assembly,       

     wherein the mechanical assembly is capable of withstanding autoclave exposure, and the sensor assembly is incapable of withstanding autoclave exposure. 
     LXVIII. The measurement module of clause LXXVIII, wherein the sensor assembly comprises an unsealed electrical component. 
     LXIX. The measurement module of clause LXXVIII, wherein the mechanical assembly is free of electrical components. 
     LXX. The measurement module of clause LXXVIII, wherein the mechanical assembly comprises a first casing, and the detection element is a probe movably disposed at least partially within the first casing, and the probe is configured to be linearly displaced relative to the first casing. 
     LXXI. The measurement module of clause LXX, wherein the sensor assembly comprises a second casing, the second casing being removably coupleable to the first casing of the mechanical assembly. 
     LXXII. The measurement module of clause LXXI, wherein the detection element comprises:
         a cannula movably coupled to the first casing; and   a gear movably coupled to the cannula and configured to rotate in response to the cannula being linearly displaced,   wherein the sensor assembly is engaged with the gear to detect a characteristic of rotation of the gear when the first casing is coupled to the second casing.       

     LXXIII. The measurement module in any one of clauses LXXI-LXXII, wherein the sensor assembly comprises a sensor, wherein the sensor is secured to the second casing such that the sensor is positioned to operatively engage the detection element when the second casing is coupled to the first casing. 
     LXXIV. The measurement module of clause LXXIII, wherein the sensor assembly comprises a circuit and a sensor coupled to the circuit, the sensor is configured to provide an input signal based on the distance moved by the detection element, and the circuit is configured to determine the distance moved by the detection element based on the input signal and generate a notification signal to notify a user based on the distance moved by the detection element. 
     LXXV. The measurement module of clause LXXIV, wherein the sensor assembly further comprises a visual indicator electrically coupled to the circuit and configured to receive the notification signal from the circuit to display an indicator of the distance moved by the detection element based on the notification signal. 
     LXXVI. The measurement module of clause LXXIV, wherein the sensor comprises an electrical sensor. 
     LXXVII. The measurement module in any one of clauses LXXIII-LXXVI, wherein the sensor assembly further comprises a power receiver, the power receiver is configured to receive power from the handheld surgical instrument when the measurement module is coupled to the handheld surgical instrument. 
     LXXVIII. A handheld surgical instrument comprising: 
     a housing comprising a distal region, a proximal region, and a barrel extending from the distal region towards the proximal region; and 
     a drive system comprising a rear drive point positioned within the proximal region of the housing and a forward drive point positioned within the distal region of the housing, the forward drive point and the rear drive point each capable of driving a respective one of an attachment or a surgical end effector coupled thereto. 
     LXXIX. The handheld surgical instrument of clause LXXVIII, further comprising a measurement module configured to be removably coupled to the distal region of the housing of the surgical instrument when the surgical end effector is removably coupled to the rear drive point. 
     LXXX. The handheld surgical system of clause LXXIX, further comprising an attachment removably coupleable to the forward drive point of the drive system when the distal region of the housing of the surgical instrument is free of the measurement module. 
     LXXXI. The handheld surgical instrument of clause LXXX, wherein the drive system comprises: 
     a driving cannula comprising a length terminating at one end portion with the rear drive point integrated therein and an opposing end portion with the forward drive point integrated therein, and the driving cannula is rotatably disposed within the housing; 
     a motor providing a torque; and 
     a gear train configured to increase the torque provided by the motor and transmit the torque to the driving cannula. 
     LXXXII. The handheld surgical instrument in any one of clauses LXXIX-LXXXI, wherein the measurement module comprises a casing, a circuit disposed within the casing, and a power receiver coupled to the circuit,
         wherein the housing comprises a power supply configured to supply power to the power receiver for the measurement module when the measurement module is coupled to the housing.       

     LXXXIII. A method for using a measurement module with a handheld surgical instrument having a proximal region and a distal region to provide measurement functionality to the handheld surgical instrument, the measurement module comprising a mechanical assembly that comprises a detection element and a sensor assembly removably coupleable to the mechanical assembly and operatively engageable with the detection element of the mechanical assembly, the method comprising:
         coupling the measurement module to a first handheld surgical instrument;       

     using the first handheld surgical instrument during a first surgical session in a manner that causes the detection element to move a distance indicative of a procedural parameter;
         sensing the distance moved by the detection element with the sensor assembly;   decoupling the sensor assembly from the mechanical assembly of the measurement module;   discarding the sensor assembly of the measurement module after the first surgical session; and   reusing the mechanical assembly of the measurement module during a second surgical session with the first handheld surgical instrument or a second handheld surgical instrument different from the first handheld surgical instrument.       

     LXXXIV. The method of clause LXXXIII, further comprising sterilizing the mechanical assembly after the first surgical session. 
     LXXXV. The method in any one of clauses clause LXXXIII-LXXXIV, further comprising coupling the mechanical assembly of the measurement module with a second sensor assembly to provide measurement functionality during the second surgical session. 
     LXXXVI. The method of any one of clauses LXXXIII-LXXXV, further comprising coupling a surgical end effector to the proximal region of the handheld surgical instrument when the measurement module is coupled to the first handheld surgical instrument. 
     LXXXVII. The method of clause LXXXVI, further comprising coupling an attachment to the distal region of the handheld surgical instrument when the first handheld surgical instrument is free of the measurement module. 
     LXXXVIII. A modular surgical system comprising:
         a handheld surgical instrument comprising a housing and a drive system;   an attachment removably coupleable to the handheld surgical instrument, the attachment capable of performing an operational function; and   a measurement module removably coupleable to the handheld surgical instrument, the measurement module capable of performing a measurement function associated with the operational function.       

     LXXXIX. The modular surgical system of clause LXXXVIII wherein the housing of the handheld surgical instrument comprises a first coupler, and the measurement module comprises a second coupler removably coupleable to the first coupler of the handheld surgical instrument, and the attachment comprises a third coupler removably coupleable to the first coupler of the handheld surgical instrument. 
     XC. The modular surgical system any one of clauses LXXXVIII-LXXXIX wherein the measurement module is configured to receive only electrical energy from the handheld surgical instrument in order to perform the measurement function. 
     XCI. The modular surgical system of clause LXXXVIII wherein the attachment is configured to receive only mechanical energy from the drive system in order to perform the operational function. 
     XCII. A surgical handpiece assembly for operating a drill bit having one or more resilient arms to engage the surgical handpiece, the surgical handpiece assembly comprising: 
     a housing assembly comprising a proximal region and a distal region; 
     a drive element rotatably coupled to the housing assembly and configured to receive torque from and rotate in response to a motor, the drive element comprising a driving portion configured to transmit torque to the drill bit; 
     a retention surface adjacent the proximal end of the drive element configured to assist the one or more resilient arms of the drill bit to retain an axial position of the drill bit relative to the drive cannula; and
         a release assembly proximal the proximal end of the drive element, the release assembly comprising a release member moveable relative to the retention surface to a first position and a second position, the release member configured to operatively disengage the one or more resilient arms of the drill bit from engagement with the retention surface to permit the drill bit to move axially relative to the drive element in response to the release member moving from the first position to the second position.       

     XCIII. A surgical handpiece system for performing measurement functions and surgical operations, the surgical handpiece system comprising: 
     a handpiece assembly comprising,
         a handpiece housing assembly comprising a proximal region and a distal region, and the handpiece housing assembly comprising a handpiece coupler adjacent the distal region, and   a drive element rotatably coupled to the handpiece housing assembly, the drive cannula extending along a longitudinal axis and being configured to receive torque from a motor;       

     a surgical attachment module removably coupleable to the handpiece housing assembly adjacent the distal region, the surgical attachment module comprising,
         a surgical attachment housing comprising a surgical attachment coupler adapted to cooperate with the handpiece coupler to removably couple the surgical attachment housing to the handpiece housing assembly adjacent the distal region, and   a drive shaft rotatably coupled to the surgical attachment housing and configured to receive torque from the drive element to operate an end effector; and       

     a measurement module removably coupleable to the handpiece housing assembly adjacent the distal region, the measurement module being configured to perform measurement functions associated with operation of the handpiece assembly, and the measurement module comprising a measurement housing and a measurement coupler, wherein the measurement coupler is configured to cooperate with the handpiece coupler to removably couple the measurement housing to the handpiece housing assembly adjacent the distal region.