Patent Publication Number: US-2022218362-A1

Title: Surgical rotational tool driver and method

Description:
FIELD OF THE INVENTION 
     This invention relates to a surgical rotational tool driver. This invention also relates to a method of operating a surgical rotational tool driver. 
     BACKGROUND OF THE INVENTION 
     Surgical rotational tool drivers allow torque to be transmitted to a surgical rotational tool from a rotational power tool. An example of a surgical rotational tool driver is an acetabular reamer driver for use with an acetabular reamer. 
     Hip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant. As part of a hip replacement procedure, an acetabulum of the patient may be prepared for receiving an acetabular cup implant by reaming it to an appropriate size and depth. An acetabular reamer may have a substantially hemispherical dome to be received in the acetabulum. The acetabular reamer may also include features located on an outer surface of the dome for grating the inner surface of the acetabulum as the reamer rotates. The acetabular reamer may be releasably attached to a distal end of an acetabular reamer driver, to allow the surgeon to manipulate it (e.g. to position the dome within the acetabulum and to apply a force for pressing the reamer against the inner surface of the acetabulum as the reamer rotates). A driveline may extend within the acetabular reamer driver for transmitting torque to the acetabular reamer. 
     The acetabular reamer driver may include a release mechanism for releasing the acetabular reamer from the acetabular reamer driver. 
     SUMMARY OF THE INVENTION 
     Aspects of the invention are set out in the accompanying independent and dependent claims. Combinations of features from the dependent claims may be combined with features of the independent claims as appropriate and not merely as explicitly set out in the claims. 
     According to an aspect of the invention, there is provided a surgical rotational tool driver comprising: 
     a substantially hollow shaft having a proximal end, a distal end; a driveline extending within the hollow shaft, the driveline having:
         a proximal end connectable to a rotational power tool for applying torque through the driveline; and   a head part extending distally from the distal end of the shaft, the head part including connection features for connecting to a connection member of a surgical rotational tool, the head part having an axis of rotation for rotation of the surgical rotational tool on rotation of the driveline, the connection features of the head part comprising:   a housing;   a pair of jaw members, each jaw member including a pair of jaws for receiving the connection member of the surgical rotational tool, wherein each jaw member is pivotally mounted on the housing for rotation about an axis substantially perpendicular to the axis of rotation of the head part between:
           a first position for receipt of the connection member within the jaws of each jaw member; and   a second position for retaining the connection member within the jaws of each jaw member to prevent removal of the surgical rotation tool from the surgical rotational tool driver; and a locking mechanism comprising:   a pair of catches for engaging with a respective catch of each jaw member to lock the jaw members in the second position, and   a release member slideably moveable within the housing to release the catches of the locking mechanism from the respective catches of the jaw members to allow the jaw members to return to the first position for removal of the surgical rotational tool from the surgical rotational tool driver.   
               

     According to another aspect of the invention, there is provided a method of operating a surgical rotational tool driver, the method comprising: 
     connecting one or more connection features of a head part of a driveline of a surgical rotational tool driver to a connection member of a surgical rotational tool, the surgical rotational tool driver comprising:
         a substantially hollow shaft having a proximal end, a distal end;   a driveline extending within the hollow shaft, the driveline having:
           a proximal end connectable to a rotational power tool for applying torque through the driveline; and   said head part extending distally from the distal end of the shaft, the head part having an axis of rotation for rotation of the surgical rotational tool on rotation of the driveline, the connection features of the head part comprising:   a housing;   a pair of jaw members, each jaw member including a pair of jaws for receiving the connection member of the surgical rotational tool, wherein each jaw member is pivotally mounted on the housing for rotation about an axis substantially perpendicular to the axis of rotation of the head part between:
               a first position for receipt of the connection member within the jaws of each jaw member; and   a second position for retaining the connection member within the jaws of each jaw member to prevent removal of the surgical rotation tool from the surgical rotational tool driver; and   
               a locking mechanism comprising:
               a pair of catches for engaging with a respective catch of each jaw member to lock the jaw members in the second position, and   a release member slideably moveable within the housing to release the catches of the locking mechanism from the respective catches of the jaw members to allow the jaw members to return to the first position for removal of the surgical rotational tool from the surgical rotational tool driver;   
               
               

     operating the release mechanism by sliding the release member within the housing; and removing the surgical rotational tool from the surgical rotational tool driver. 
     The jaw members of the claimed invention can provide for convenient mounting of a surgical rotational tool on the surgical rotational tool driver. Moreover, the locking mechanism including the catches and slideable release member can provide for a secure yet easily releasable connection between the surgical rotational tool driver and the surgical rotational tool. 
     The catches of the locking mechanism may each comprise a ramped surface extending laterally from the release member, and a retaining surface located at an end of the ramped surface. The catches of the jaw members are operable to ride along the ramped surface as the jaw members pivot from the first position to the second position and engage with the retaining surfaces when they reach the end of the ramped surface to lock the jaw members in the second position. This arrangement can allow the locking mechanism to be locked down by simple insertion of the connection member into the jaws of the jaw members. In particular, as the jaw members pivot and reach the second position, this automatically locks the jaw members because the catches of the jaw members engage with the retaining surfaces located at the ends of the ramps. 
     The release member may be slideably moveable within the housing to disengage the catches of the jaw members from the retaining surfaces of the catches on the release member. This can allow the jaw members to return to the first position, for convenient disconnection of the surgical rotational tool from the surgical rotational tool driver. In some embodiments, the release member may be slideably moveable along a direction substantially parallel to the axis of rotation of the head part. 
     The locking mechanism may further comprise a biasing element located within the housing for biasing the release member along the axis of rotation of the head part in a distal direction. This can bias the release member into a position in which the catches of the jaw members remain engaged with the retaining surfaces of the catches on the release member, whereby the secureness of the connection between the surgical rotational tool driver and the surgical rotational tool may be improved. 
     The housing may include an opening through which the catches of the jaw members engage with the ramped surface and the retaining surface of the catches on the release member. This can allow the jaw members to be located externally with respect to the housing, whereby their rotation during use does not interfere with the sliding movements of the release member, and vice versa. 
     The locking mechanism may further comprise a biasing element mounted on the housing further biasing the jaw members toward the first position. This can allow for the automatic return of the jaw members to the first position on operation of the release member. 
     The biasing element may comprise a leaf spring having a first end for biasing a first of the jaw members and a second end for biasing a second of the jaw members. 
     The release member may include at least one distally facing recess for receiving the connection member of the surgical rotational tool. 
     The driveline may be substantially hollow. The locking mechanism may further comprise an actuation member extending within the substantially hollow driveline. A distal end of the actuation member may be attached to the release member. The actuation member may be connected to the release mechanism for operating the release member from a position on the surgical rotational tool driver located proximally with respect to the head part. The provision of the actuation member within the driveline allows the release mechanism to be operated at a position that is located away from the distal end of the shaft. This may be more convenient for the surgeon, as the distal end of the shaft may not be easily accessible when it is located in the wound. Moreover, the provision of the actuation member within the driveline may allow an outer surface of at least the distal end of the shaft to be substantially free of clutter associated with the features (buttons, catches and the like) of a release mechanism, which may otherwise interfere with and damage soft tissue in the wound. In the absence of such features on its outer surface, the distal end of the shaft may thus have an uncluttered (e.g. smooth) and relatively narrow profile, which may also facilitate its easy insertion and extraction through the wound. 
     The substantially hollow shaft may have at least one bend and the driveline may have a universal joint located at each bend in the shaft. 
     The actuation member may be substantially flexible, to allow it to navigate any bends in the shaft. The actuation member may comprise a substantially flexible tension member, such as a wire. 
     The actuation member may be a polymer. The actuation member may comprise an alloy. 
     The or each universal joint may include a substantially hollow central portion through which the actuation member extends. This may allow the actuation member to extend within the driveline without interfering with the operation of the driveline. For instance, the or each universal joint may connect an end of a driveline section of the driveline to an end of another driveline section of the driveline. The or each universal joint may include a spider part pivotally attached to the end of each driveline section; and an aperture in the spider part. The actuation member may extend though the aperture. 
     The surgical rotational tool driver may be a reamer driver. For instance, the reamer driver may be an acetabular reamer driver. The surgical rotational tool may be an acetabular reamer. 
     According to another aspect of the invention, there is provided a surgical kit comprising a surgical rotational tool driver as defined in any of claims  1  to  16  and a surgical rotational tool having said connection member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will be described hereinafter, by way of example only, with reference to the accompanying drawings in which like reference signs relate to like elements and in which: 
         FIG. 1  shows a surgical rotational tool driver; 
         FIG. 2A  shows a cross section of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 2B  shows the surgical rotational tool driver of  FIG. 1  with a surgical rotational tool attached; 
         FIGS. 3 and 4  show the driveline of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 5  shows a cross section of the driveline of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 6  shows a cross section of the distal end of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 7  shows a distal end of the driveline of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 8  shows some of the features of a universal joint of the driveline of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 9  shows a spider part of a universal joint of a driveline of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 10  shows a cross section of an actuation mechanism of the surgical rotational tool driver of  FIG. 1  (the driveline is not shown in  FIG. 10 ); 
         FIG. 11  shows another cross section of the actuation mechanism of the surgical rotational tool driver of  FIG. 1 ; 
         FIG. 12  shows a cut away view of the actuation mechanism of the surgical rotational tool driver of  FIG. 1  (the driveline is not shown in  FIG. 12 ); 
         FIG. 13  shows a surgical rotational tool driver according to another embodiment of the invention; 
         FIGS. 14A to 14C  illustrate the attachment of a surgical rotational tool (such as an acetabular reamer) to the surgical rotational tool driver of  FIG. 13 ; and 
         FIGS. 15 to 25  show the connection features of the surgical rotational tool driver of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention are described in the following with reference to the accompanying drawings. 
       FIG. 1  shows a surgical rotational tool driver  10 . The surgical rotational tool driver includes a substantially hollow shaft  2 . The substantially hollow shaft  2  may be elongate. The substantially hollow shaft  6  has a proximal end  4  and a distal end  6 . 
     The substantially hollow shaft  2  includes at least one bend. Each bend is located along the substantially hollow shaft  2 , inteimediate the proximal end  4  and the distal end  6 . The surgical rotational tool driver  10  in this example is an offset driver including two bends  22 ,  24 . It is envisaged however that the substantially hollow shaft  2  may include a single bend, or more than two bends. 
     In the present example, the bend  22  is located distally with respect to the bend  24 . Each bend may be located at the interface between two shaft sections of the substantially hollow shaft  2 . For instance, in the present example, the substantially hollow shaft  2  includes a distal shaft section  12 , an intermediate shaft section  14  and a proximal shaft section  16 . The distal shaft section  12  extends distally from the bend  22 . The intermediate shaft section  14  extends between the bend  22  and the bend  24 . The proximal shaft section  16  extends proximally from the bend  24 . Each shaft section may be substantially cylindrical. 
     Each shaft section may have a longitudinal axis. The bend(s) may set the longitudinal axes of the various shaft sections at certain angles (e.g. ±30°, ±45°) to each other. The bend(s) in the substantially hollow shaft  2  may allow the surgeon to work around soft tissue in the wound space, while using the surgical rotational tool driver  10 . 
     As shown in, for example,  FIGS. 2A and 3 to 5 , the surgical rotational tool driver  10  also includes a driveline  30 . The driveline  30  is substantially hollow. The driveline  30  extends within the substantially hollow shaft  2 . The driveline  30  allows torque to be transmitted through the surgical rotational tool driver  10  by rotating within the substantially hollow shaft  2 . In particular, the driveline  30  has a proximal end that may be connected to a rotational power tool for applying torque through the driveline  30 . 
     To accommodate the bend(s) in the substantially hollow shaft  2 , the driveline  30  includes at least one universal joint. Each universal joint is located at a respective one of the bend(s). In the present example, the driveline  30  includes a universal joint  80  located at the bend  22  and a universal joint  70  located at the bend  24 . An example of the universal joints will be described in more detail below in relation to  FIGS. 8 and 9 . 
     Each universal joint may be located at the interface between two driveline sections of the driveline  30 . For instance, in the present example, the driveline  30  includes a distal driveline section  30 A, an intermediate driveline section  30 B and a proximal driveline section  30 C. The distal driveline section  30 A extends distally from the universal joint  70  located at the bend  22 . The intermediate driveline section  30 B extends between the universal joint  70  located at the bend  22  and the universal joint  70  located at the bend  24 . The proximal driveline section  30 C extends proximally from the universal joint  70  located at the bend  24 . The proximal end of the proximal driveline section  30 C may be connected to a rotational power tool for applying torque through the driveline  30  as noted above. Each driveline section may be substantially cylindrical. 
     The various driveline sections of the driveline may be positioned for rotation within a respective one of the shaft sections of the substantially hollow shaft  2 . Each driveline section may have a longitudinal axis. The longitudinal axes of the driveline sections may be coaxially aligned with the longitudinal axes of their respective shaft sections. For instance, in the present example, the distal driveline section  30 A rotates within the distal shaft section  12 , the intermediate driveline section  30 B rotates within the intermediate shaft section  14 , and the proximal driveline section  30 C rotates within the proximal shaft section  16 . 
     As can be seen in  FIGS. 1 to 7 , the driveline  30  also includes a head part  40 . The head part  40  of the driveline  30  extends distally from the distal end of the substantially hollow shaft  2 . In the present example, the head part  40  is located at a distal end of the distal driveline section  30 A. The head part  40  may have a substantially cylindrical outer surface. As can be seen in, for instance,  FIGS. 1, 2A and 6 , a diameter of the substantially cylindrical outer surface of the head part  40  may match a diameter of a substantially cylindrical outer surface of the distal shaft section  12 , so that there is substantially no change in the outer diameter of the surgical rotational tool driver  10  at the interface between the distal end of the distal shaft section  12  and the head part  40 . 
     The head part  40  is connectable to a surgical rotational tool. The surgical rotational tool may for instance be a reamer, such as an acetabular reamer  100  as shown in  FIG. 2B . As shown in  FIG. 2B , the acetabular reamer  100  may, for instance comprise a hemispherical dome  102  for insertion into the acetabulum of a patient. An outer surface of the dome  102  may include features  104  for grating bone away from the inner surface of the acetabulum as the acetabular reamer  100  rotates with the driveline  30 . 
     To implement the connection between the head part  40  and the surgical rotational tool, the head part  40  may include distally located connection features  42  for connection with corresponding connection features of the surgical rotational tool. As shown in, for instance,  FIGS. 6 and 7 , the connection features  42  include a release mechanism for releasing the head part  40  from the surgical rotational tool. 
     In the present example, the release mechanism includes one or more teeth  44  that are receivable within openings of the corresponding connection features of the surgical rotational tool. The teeth  44  extend distally from a slideably moveable central shaft  43  of the head part  40 . The central shaft  43  may be substantially cylindrical. The central shaft  43  may be located in a centrally located bore in the head part  40 . 
     The central shaft  43  may be biased distally with respect to the other features of the head part  40  using e.g. a spring  49 . The spring  49  (which may, for instance be a helical spring as shown in  FIG. 2A ) may be located in a space located between a distally facing surface of the head part  40  and a proximally facing surface of a flange of the central shaft  43  (see the region labelled  47  in  FIG. 6 ). 
     As will be described in more detail below, the central shaft  43  may be withdrawn proximally (e.g. along the longitudinal axis of the distal driveline section  30 A—this is illustrated by the arrow labelled A in  FIG. 6 ) to withdraw the teeth  44  from the openings of the corresponding connection features. 
     As shown in, for instance,  FIGS. 2A, 5, 6, 8 and 10 to 12 , the surgical rotational tool driver  10  also includes an actuation member  60 . As noted above, the driveline  30  is substantially hollow. The actuation member  60  extends within the substantially hollow driveline  30  (see, e.g.  FIGS. 2A, 5 and 6 ). The actuation member  60  is connected to the release mechanism. This can allow the release mechanism to be operated remotely. In particular, because the actuation member  60  extends within the substantially hollow driveline  30 , the release mechanism may be operated at a position on the surgical rotational tool driver  10  that is located proximally with respect to the head part  40 . 
     In the present example, the release mechanism is operated by withdrawing the actuation member  60  proximally within the driveline  30 . A distal end  62  of the actuation member  60  is attached to the central shaft  43 , as shown in  FIGS. 2A and 6 . To implement the attachment of the actuation member  60  to the central shaft  43 , in the present example the central shaft  43  includes a central axial bearing surface within which the actuation member  60  is rotationally received. The central axial bearing surface of the central shaft  43  includes an axial bore in the central shaft  43 . The distal end of the actuation member  60  is received within and extends within the bore. The bore has a narrowed portion  46 , which may be located at a proximal end of the bore. The actuation member  60  has a widened part  62 , which is located distally with respect to the narrowed portion  46  of the bore. 
     In use, when the actuation member  60  is withdrawn proximally within the driveline  30  as noted above (see the arrows labelled A, B and C in  FIGS. 2A and 6 ), the widened part  62  of the actuation member  60  urges against the narrowed portion  46  whereby the central shaft  43  is moved proximally (e.g. against the bias provided by the spring  49 ), which in turns disengages the teeth  44  from the above described openings of the corresponding connection features of the surgical rotational tool. This allows the surgical rotational tool to be released from the head part  40  of the driveline  30 . 
     The actuation member  60  may also by withdrawn proximally while the surgical rotational tool is being mounted on the head part  40 . This may allow other connection features  42  of the head part  40  and the corresponding connection features of the surgical rotational tool to be manipulated into the correct position without interference from the teeth  44  of the central shaft  43 . 
     During rotation of the driveline  30  to transmit torque to the surgical rotational tool, it is envisaged that the driveline  30  may rotate relative to the actuation member  60 . For instance, the actuation member  60  may remain substantially stationary during rotation of the driveline  30 . In the present example, the distal end of the actuation member  60  is rotationally received within the bore in the central shaft  43 , to allow relative rotation between the actuation member  60  and the driveline  30 . The inner bearing surface of the bore, and the surface of (at least the distal end of) the actuation member  60  may be smooth, so as to reduce friction between them as the driveline  30  rotates. It is anticipated that residual friction forces between the actuation member  60  and the inner bearing surface of the bore may cause some rotation of the actuation member  60  while the driveline  30  rotates, although it is anticipated that the angular velocity of the actuation member  60  would typically be substantially lower than that of the driveline  30 . Similar considerations apply to the passage of the actuation member  60  through the substantially hollow central portion of the spider part(s) to be described below. Similar considerations also apply to attachment between the actuation member  60  to the inner sleeve  90  of the actuation mechanism to be described below, to allow relative rotation between the actuation member  60  to the inner sleeve  90  during rotation of the driveline  30 . 
     The actuation member  60  may be substantially flexible. This may allow the actuation member  60  to navigate the bend(s)  22 ,  24  in the substantially hollow shaft  2 . In some examples, the actuation member  60  may comprise a substantially flexible tension member. The actuation member  60  may, for instance, comprise a substantially flexible wire. 
     The actuation member  60  may comprise a polymer. In one example, the actuation member  60  may comprise Polytetrafluoroethylene (PTFE). In another example, the actuation member  60  may comprise polyethylene. For instance, an ultra-high molecular weight polyethylene could be used (e.g. Dyneema). In a further example, the actuation member  60  may comprise poly-para-phenylene terepthalamide (Kevlar). 
     The actuation member  60  may, for instance, comprise an alloy. For instance, the alloy may be Nickel Titanium (Nitinol). 
     As noted above, the actuation member  60  extends within the substantially hollow driveline  30 . As noted above, the flexible nature of the actuation member  60  can allow it to navigate the bend(s)  22 ,  24  in the substantially hollow shaft  2 . The universal joint(s)  70  may be configured to allow the actuation member  60  to pass through it in such a way that it does not interfere with the operation of the universal joint(s)  70  during rotation of the driveline  30 . 
     With reference to  FIGS. 7 and 8 , each universal joint  70  in this example includes a pair of yokes, each yoke being located at an end of one of the two driveline sections that the universal joint  70  connects together. Each yoke includes a pair of aims  76 . The arms  76  may be arranged at regular intervals around the universal joint (typically, as shown in the figures, the arms  76  of a first yoke are arranged at the 12 o&#39;clock and 6 o&#39;clock positions, while the arms  76  of a second yoke are arranged at the 3 o&#39;clock and 9 o&#39;clock positions. 
     The universal joint(s)  70  may include a substantially hollow central portion, through which the actuation member  60  extends. In the present example, the substantially hollow central portion is comprised of a spider part  80  (see  FIG. 9 ). 
     The spider part  80  may include a body part  88 . The body part  88  may be located at the center of the spider part  80 . The spider part  80  may also include a number of legs  84 . The legs may extend radially outward from the body part  88 . The legs  84  may be circumferentially distributed around the body part  88 . An end of each leg  84  is pivotally attached to one of the arms  76  of the yokes located at the ends of the driveline sections that the universal joint  70  interconnects. As shown in  FIG. 8 , the ends of the legs  84  may pass through openings in the arms  76  to faun pivotal connections  74 . These pivotal connections allow the tilting of the driveline sections that the universal joint  70  interconnects, relative to each other, so as to allow the substantially hollow driveline  30  to navigate the bend(s)  22 ,  24  in the substantially hollow shaft  2 . 
     In the present example, the spider part  80  has four legs  84 , which are circumferentially distributed around the body part  88  at the 12 o&#39;clock, 3 o&#39;clock, 6 o&#39;clock and 9 o&#39;clock positions, for pivotal attachment to a respective one of the arms  76 . By way of example, the pivotal attachment of two of the legs  84  of a spider part  80  to the arms  76  of a yoke provided at the proximal end of the distal driveline section  30 C is shown in  FIG. 8 . 
     The spider part  80  includes an aperture  82 . The aperture  82  passes though the body part  88 . The aperture  82  is may be centrally located within the body part  88 . The actuation member  60  extends though the aperture  82 . The intermediate driveline section  30 B is omitted in  FIG. 8  to reveal the path of the actuation member  60  through the driveline and in particular through the aperture  82 . 
     The provision of the aperture  82  in the body part  88  of the or each universal joint  70  of the driveline  30  can allow the actuation member  60  to extend within the substantially hollow driveline  30  while navigating the bend(s)  22 ,  24  in the substantially hollow shaft  2 . 
     As mentioned above, it is envisaged that, during rotation of the driveline  30  to transmit torque to the surgical rotational tool, the driveline  30  may rotate relative to the actuation member  60 . To allow this, the actuation member  60  is rotationally received within the aperture  82  in the body part  88 . The inner surface of the aperture  82  and the surface of the actuation member  60  may be smooth, so as to reduce friction between them as the driveline  30  rotates. It is anticipated that residual friction forces between the actuation member  60  and the inner surface of the aperture  82  may cause some rotation of the actuation member  60  while the driveline  30  rotates, although it is anticipated that the angular velocity of the actuation member  60  would typically be substantially lower than that of the spider part  80 . 
     In some examples, the surgical rotational tool driver  10  may include an actuation mechanism. The actuation mechanism may be located along the substantially hollow shaft  2 . It is envisaged that the actuation mechanism may be located in a position that is remote from the distal end  6  of the substantially hollow shaft  2 . In this position the actuation mechanism may be conveniently accessible by the surgeon. For instance, the actuation mechanism may be located outside the wound space even while the surgical rotational tool driver  10  is being used (i.e. while a surgical rotational tool attached to the head part  40  is located inside the wound space). In some examples, the actuation mechanism may be located proximally with respect to a mid-way point located equidistant the proximal end  4  and the distal end  6  of the substantially hollow shaft  2 . In some examples, the actuation mechanism may be located at the proximal end of the substantially hollow shaft  2 . 
     In the present example, the surgical rotational tool driver  10  includes an actuation mechanism that is located along the proximal shaft section  16  of the substantially hollow shaft  2 . It is envisaged that the actuation mechanism may instead be located along the intermediate shaft section  14  of the substantially hollow shaft  2 . 
     The actuation mechanism is operable to withdraw the actuation member  60  proximally within the driveline  30 . As described above, the withdrawal of the actuation member  60  proximally within the driveline  30  operates the release mechanism for releasing the head part  40  from a surgical rotational tool. 
     The actuation mechanism of the present example will be described below with reference to  FIGS. 10 to 12 . 
     The release mechanism in this example includes an inner sleeve  90 . The inner sleeve  90  may be substantially cylindrical. The inner sleeve  90  is mounted inside the proximal driveline section  30 C of the driveline  30  (see  FIG. 11 —note that the driveline is not shown in  FIG. 10 or 12 , so as to reveal the inner sleeve  90 , its attachment to the actuation member  60  and the interaction between the inner sleeve  90  and the intermediate sleeve  100  to be described below). The inner sleeve  90  is configured to rotate with the driveline  30  (e.g. see the arrows labelled D in  FIGS. 10 and 11 ). 
     In this example, a proximal end of the actuation member  60  is attached to the inner sleeve  90 . To implement the attachment of the actuation member  60  to the inner sleeve  90 , the inner sleeve  90  is provided with a central opening that has an axial bearing surface within which the actuation member  60  is rotationally received. In this example, the central opening comprises a bore. The bore has a narrowed portion  92 , which may be located at a proximal end of the bore. The actuation member  60  has a widened part  64 , which is located proximally with respect to the narrowed portion  92  of the bore. By operating the actuation mechanism to move the inner sleeve  90  proximally, the actuation member  60  may be withdrawn in a proximal direction (see the arrow labelled C in  FIG. 11 ) within the driveline  30  as described above. 
     In this example, the driveline  30  has one or more openings  32  located in a side wall thereof. The openings  32  are slot shaped, with their long dimension substantially parallel to the longitudinal axis of the proximal driveline section  30 C. The inner sleeve  90  has one or more first members  94 . The first members  94  may be substantially cylindrical, and may extend radially outward from an outer surface of the inner sleeve  90 . The first members  94  each extend through a respective one of the opening(s)  32  located in the side wall of the driveline  30  (see also  FIG. 4 ). Note that when the driveline  30  rotates, the inner sleeve  90  rotates with the driveline  30 , owing to the engagement of the first member(s)  94  with their respective openings  32 . 
     Each first member  94  is slideable back and forth within its respective opening  32  located in the side wall of the driveline  30 , along the long dimension of the opening  32 . This can allow the inner sleeve  90  as a whole to move back and forth along the longitudinal axis of the proximal driveline section  30 C. When the inner sleeve  90  is moved proximally as noted above, an edge of the bore, formed by proximal end of the narrowed portion  92 , urges against the widened part  64  of the actuation member  60 , thereby to withdraw the actuation member  60  proximally within the driveline  30 . 
     As described above, it is envisaged that, during rotation of the driveline  30  to transmit torque to the surgical rotational tool, the driveline  30  (and hence the inner sleeve  90 ) may rotate relative to the actuation member  60 . For instance, the actuation member  60  may remain substantially stationary during rotation of the driveline  30  and the inner sleeve  90 . To allow this, the actuation member  60  may be rotationally received within the bore in the inner sleeve  90 . The inner surface of the bore in the inner sleeve  90  and the surface of the actuation member  60  may be smooth, so as to reduce friction between them as the driveline  30  and the inner sleeve  90  rotate. It is anticipated that residual friction forces between the actuation member  60  and the inner surface of the bore in the inner sleeve  90  may cause some rotation of the actuation member  60  while the driveline  30  and the inner sleeve  90  rotate, although it is anticipated that the angular velocity of the actuation member  60  would typically be substantially lower than that of the driveline  30  and the inner sleeve  90 . 
     In this example, the actuation mechanism also comprises an intermediate sleeve  100 . The inteanediate sleeve  100  is mounted between an outer surface of the drive line  30  and an inner surface of the substantially hollow shaft  2 . The intermediate sleeve  100  may be substantially cylindrical. 
     In this example, the proximal shaft section  16  has one or more openings  112  located in a side wall thereof. The openings  112  are slot shaped, with their long dimension substantially parallel to the longitudinal axis of the proximal shaft section  16 . The intermediate sleeve  100  has one or more second members  104 . The second members  104  may be substantially cylindrical, and may extend radially outward from an outer surface of the intermediate sleeve  100 . The second members  104  each extend through a respective one of the opening(s)  112  located in the side wall of the proximal shaft section  16 . 
     Each second member  104  is slideable back and forth within its respective opening  112  located in the side wall of the proximal shaft section  16 , along the long dimension of the opening  112 . This can allow the intermediate sleeve  100  as a whole to move back and forth along the longitudinal axis of the proximal shaft section  16  (which may be parallel to the longitudinal axis of the proximal driveline section  30 C). 
     The intermediate sleeve  100  includes a central opening having an axial bearing surface within which the (proximal driveline section  30 C of the) driveline  30  is rotationally received to allow rotation of the driveline  30  while the intermediate sleeve remains substantially stationary. Note that when the driveline  30  rotates, the intermediate sleeve  100  cannot rotate with the driveline  30 , owing to the engagement of the second member(s)  104  with their respective openings  112 . 
     In this example, a part of the central opening of the intermediate sleeve  100  has an increased diameter to foim an inwardly facing circumferential slot  106 . As can be seen in the Figures, the slot  106  may be substantially annular in shape. An outer end of the or each first member  94  of the inner sleeve  90  extending through the opening(s)  32  located in the side wall of the proximal driveline section  30 C is rotationally received within the annular slot  106 . This allows the inner sleeve  90  to rotate with the driveline  30  as described above, while the outer end of the or each first member  94  rides within the slot  106 . On the other hand, when the intermediate sleeve  100  as a whole is moved back and forth along the longitudinal axis of the proximal shaft section  16  as noted above, the edges of the slot  106  urge against the or each first member  94 , which in turn moves the or each first member  94  within its respective opening  32 , whereby the inner sleeve  90  moves axially with along the intemiediate sleeve  100 . Accordingly, by moving the intermediate sleeve  100  in a proximal direction, the inner sleeve  90  can also be moved proximally, in turn to proximally withdraw the actuation member  60  within the driveline  30  to operate the release mechanism. 
     As shown in  FIG. 12 , the intermediate sleeve  100  may include one or more apertures  108 . The aperture(s)  108  may extend radially through the sidewall of the intermediate sleeve  100  and in this example the aperture(s)  108  open out into the slot  106 . The aperture(s)  108  may allow the first members  94  to pass through them for assembly with the inner sleeve  90  during manufacture of the surgical rotational tool driver  10 . The inner sleeve  90  may include one or more radially extending bores located in an outer curved (cylindrical) surface thereof, into which the first members  94  may be inserted. 
     In this example, the actuation mechanism further comprises an outer sleeve  50 . The outer sleeve  50  is slideably mounted on an outer surface of the (proximal shaft section  16  of the) substantially hollow shaft  2 . The outer sleeve  50  may be substantially cylindrical. Proximal and/or distal ends of the outer sleeve  50  may be tapered in towards longitudinal axis of the proximal shaft section  16 , to provide the surgical rotational tool driver  10  with a smooth profile. 
     In this example, the outer sleeve  50  is connected to the or each second member  104 . In particular, the outer ends of each of the second member(s)  104  may extend radially outward through the opening(s)  112 , to be received in a respective opening  52  located in the outer sleeve  50  (e.g. see  FIG. 10 ). The openings  52  of the outer sleeve  50  within which the second member(s)  104  are received may be shaped to conform with the outer surfaces of the second member(s)  104 , so as to form a press fit between the openings  52  and the second member(s)  104 . 
     The connection of the outer sleeve  50  to the second member(s)  104  allows the outer sleeve  50  to be moved back and forth along the longitudinal axis of the proximal shaft section  16  thereby the move intermediate sleeve  100  axially. As described above, this in turn moves the inner sleeve  90  axially, so that the actuation member  60  can be withdrawn proximally to operate the release mechanism. 
     The outer sleeve  50  thus provides the surgeon with a means by which to manually operate the actuation mechanism, which in turn operates the release mechanism as described above. It is envisaged that in examples in which the central shaft  43  is biased distally (e.g., by the spring  49 ), when the surgeon releases outer sleeve  50 , each of the inner sleeve  90 , the intelinediate sleeve  100  and the outer sleeve  50  may return to a locking position of the actuation mechanism under the tension in the actuation member  60 . This locking position may thus be a default position of the actuation mechanism. A release position of the actuation mechanism may be reached by manually moving the outer sleeve  50  (and thus the inner sleeve  90  and the intermediate sleeve  100 ) proximally. 
     A method of operating a surgical rotational tool driver  10  of the kind described above may include connecting the one or more connection features  42  of the head part  40  of the substantially hollow driveline  30  to a surgical rotational tool. As noted previously, this may involve withdrawing the actuation member  60  proximally (e.g. by operating the release mechanism), to allow connection features  42  of the head part  40  and the corresponding connection features of the surgical rotational tool to be manipulated into the correct position without interference from the teeth  44  of the central shaft  43 . 
     The surgical rotational tool may, for example, be an acetabular reamer driver of the kind shown in  FIG. 2B . 
     Having attached the surgical rotational tool to the surgical rotational tool driver  10 , the method may then include applying torque through the driveline  30 . This may involve connecting a rotational power tool to the proximal end of the driveline  30  as noted above, and then operating the rotational power tool. 
     The method may also include operating the release mechanism described above to release the head part  40  from the surgical rotational tool by withdrawing the actuation member  60  proximally within the driveline  30 . 
       FIGS. 13 to 25  show a surgical rotational tool driver  10  according to another embodiment of the invention. In particular,  FIG. 13  shows the surgical rotational tool driver  10  of the present embodiment,  FIGS. 14A to 14C  illustrate the attachment of a surgical rotational tool (such as an acetabular reamer  100 ) to the surgical rotational tool driver  10 , and  FIGS. 15 to 25  show the connection features of the surgical rotational tool driver  10 . 
     The surgical rotational tool driver  10  has a number of components in common with the embodiments described above in relation to  FIGS. 1 to 12 . In particular, the components of the surgical rotational tool driver  10  located proximally with respect to the distal shaft section  12  shown in, for example,  FIG. 13 , may be the same as described above in relation to  FIGS. 1 to 12 . However, the head part  40  of the embodiment described below in relation to FIGS.  13  to  25  differs from the head part  40  described in relation to the embodiment of  FIGS. 1 to 12 . The head part  40  and its operation will now be described in detail herein below. 
     The head part  40  extends distally from the distal end  6  of the substantially hollow shaft  2  of the surgical rotational tool driver  10 . In the present example, the head part  40  is located at a distal end of the distal driveline section  30 A. The head part  40  is operable to rotate around an axis of rotation  201  (see  FIG. 16 ) under the torque transmitted to the head part  40  by the driveline  30 . 
     The head part  40  has a housing  200  the housing  200  may have a substantially cylindrical outer surface  202 , which is curved about the axis of rotation  201  of the head part  40 . The head part  40  may also have a pair of substantially flat outer lateral surfaces  248 . The lateral surfaces  248  may be provided on opposite lateral sides of the head part  40  and may separate two curved sections  202 A,  202 B (see  FIG. 16 ) of the substantially cylindrical outer surface  202  from each other. 
     As can be seen in, for instance,  FIGS. 15 and 16 , a diameter of the substantially cylindrical outer surface  202  of the head part  40  may be smaller than a diameter of a substantially cylindrical outer surface of the distal shaft section  12 . The pair of substantially flat lateral surfaces  248  may also be located inside the locus of the substantially cylindrical outer surface of the distal shaft section  12 . The can allow space for the jaw members  220  described below to be accommodated. 
     The head part  40  is connectable to a surgical rotational tool. The surgical rotational tool may for instance be a reamer, such as an acetabular reamer  100  as shown in  FIGS. 13 and 14A -C. As shown in  FIG. 13 , the acetabular reamer  100  may, for instance comprise a hemispherical dome  102  for insertion into the acetabulum of a patient. An outer surface of the dome  102  may include features  104  for grating bone away from the inner surface of the acetabulum as the acetabular reamer  100  rotates with the driveline  30 . 
     To implement the connection between the head part  40  and the surgical rotational tool, the head part  40  includes a number of connection features for connection with the corresponding connection features of the surgical rotational tool. The connection features of the surgical rotational tool may comprise one or more members  110 ,  111 . In the present embodiment, the connection features of the surgical rotational tool include two member  110 ,  111  which extend across a proximal end of the surgical rotational tool. The members  110 ,  111  are arranged at right angles to each other. The connection features of the head part  40  include a release mechanism for releasing the head part  40  from the surgical rotational tool  100 . The connection features of the head part  40  will now be described in detail. 
     The connection features of the head part include a pair of jaw members  220 . Each jaw member  220  may be located adjacent a respective one of the substantially flat outer lateral surfaces  248  of the housing  200 . Each jaw member  220  includes a pair of jaws  222 ,  224  defining a space  229  for receiving the connection member  111  of the surgical rotational tool. 
     The housing  200  also includes further spaces  208 ,  210  for receiving the connection member  111  and two further spaces  204 ,  206  for receiving the connection member  110 . Each space  204 ,  206 ,  208 ,  210  is defined by a respective pair of jaws (e.g. see  FIG. 17 , which shows the head part  40  with the jaw members  220  removed). Note that the spaces  208  and  210  are substantially aligned with the spaces  229  defined by the jaws  222 ,  224  of the jaw members  220 , whereby the connection member  111  of the surgical rotational tool can be received within both the spaces  208 ,  210  and the spaces  229  when the surgical rotational tool is connected to the head part  40 . 
     Each jaw member  220  is pivotally mounted on the housing  200 . In this embodiment, the each substantially flat outer lateral surface  248  of the housing  200  includes a laterally extending post  226  and each jaw member includes a bore  227  within which one of the laterally extending posts  226  is received. This allows each jaw member  220  to rotate about an axis that is substantially perpendicular to the axis  201  of rotation of the head part  40 . The jaw members  220  are each rotatable between a first position (e.g. see  FIGS. 14A and 24 ) in which the connection member  111  of the surgical rotational tool can be introduced into the spaces  229  defined by the pairs of jaws  222 ,  224 , and second position (e.g. see  FIGS. 14C, 15 and 25 ) in which the connection member  111  is retained within the spaces  229  defined by the jaws  222 ,  224  of each jaw member  220 , thereby to prevent removal of the surgical rotation tool from the surgical rotational tool driver  10 . As will be described below, each pair of jaws  222 ,  224  includes a substantially flat, inner surface  228 , against which the connection member  111  may urge as it is introduced into the spaces  229 , thereby to cause the jaw members  220  to rotate between the first position and the second position. 
       FIGS. 14A to 14C  illustrate the positions of the jaw members  220  at various stages in the connection of the surgical rotation tool (in this example an acetabular reamer  100 ) to the surgical rotational tool driver  10 . 
     In a first stage, shown in  FIG. 14A , the jaw members  220  are initially in the first position noted above. In the first position, the spaces  229  defined by the pairs of jaws  222 ,  224  are presented distally, to allow the connection member  111  of the surgical rotational tool to be inserted into the spaces by moving the surgical rotational tool driver  10  toward the proximal end of the surgical rotational tool. Note that as the connection member is introduced into the spaces  229 , the optional connection member  110  may also be introduced into the spaces  204 ,  206  defined in the housing  200 . 
     In a next stage, shown in  FIG. 14B , as the head part  40  continues to move toward the surgical rotational tool, the connection member  111  begins to urge against the substantially flat inner surface  228  of the jaw members  220 . This causes the jaw members to begin to rotate about the pivot points defined by the posts  226 , toward the second position. 
     In a next stage, shown in  FIG. 14C , the jaw members  220  reach the second position. With reference to  FIG. 19 , it is noted that the jaw  224  of each jaw member  220  is curved around an axis parallel to the axis of rotation of each jaw member  220 . Because of this, when the jaw members  220  are in the second position, the ends of the jaws  224  are positioned so as to block movement of the connection members  111  in the distal direction. This prevents removal of the connection member  111  from the spaces  229 , thereby preventing disconnection of the surgical rotational tool from the surgical rotational tool driver  10 . 
     In some embodiments, the jaw members  220  may be resiliently biased toward the first position. An example of this approach will now be described with reference to  FIGS. 14A-C ,  24  and  25 . In this example, a biasing element is mounted on the housing  200 . The biasing element may comprise an elongate leaf spring  260  having a middle section  260 A and two ends  260 B. The middle section  260 A of the leaf spring  260  may be located in a laterally extending slot provide in the curved surface  260 B of the housing  200 . The ends  260 B may be angled to extend toward the jaw members  220 . In the first position (e.g. see  FIG. 24 ), the jaw members  220  may rest against the jaw members  220 . As the jaw members  220  begin to rotate toward the second position as described above in relation to  FIG. 14A-C , the jaw members urge against the ends  260 B of the leaf spring  260 , causing the middle section  260 A to bend, thereby to resist the rotation of the jaw members  220 . This biasing of the jaw member  220  toward the first position may assist in returning the jaw members to the first position, for subsequent removal of the connection member  111  form the spaces  229 , during disconnection of the surgical rotational tool from the surgical rotational tool driver  10 . 
     The surgical rotational tool driver  10  also has a locking mechanism. This locking mechanism can lock the jaw members  220  in the second position when the connection member  111  is received as shown in  FIG. 14C . This can prevent the inadvertent removal of the connection member  111  from the spaces  229  during use of the surgical rotational tool. Note that while the jaw members  220  are locked in the second position, the jaw members  220  are prevented from returning to the first position under the action of the optional biasing element described above. 
     The locking mechanism of the present embodiment will now be described with reference to  FIGS. 16-20 . 
     The locking mechanism in this embodiment includes a release member  270 . The release member  270  is located in a cavity defined by the housing  200 . The release member  270  is slideably moveable within the housing  200 . In particular, and with reference to  FIG. 16 , the release member  270  is slideable in a distal/proximal direction along the axis of rotation  201 . The release member  270  may be arranged coaxially with the housing  200  for rotation about the axis  201  with the housing  200 . The release member  270  is biased distally by a biasing element such as a helical spring  310 . The biasing element may be located in the cavity defined by the housing, at a proximal position with respect to the release member  270 . The biasing element may urge against a proximal end  292  of the release member  270  and against a lip  312  provided at a proximal end of the cavity defined by the housing  200 , thereby to bias the release member  270  in the distal direction. 
     In the present embodiment, the release member  270  is operated by withdrawing the actuation member  60  proximally within the driveline  30 . A distal end  62  of the actuation member  60  is attached to the release member  270 , as shown in, for example,  FIG. 16 . To implement the attachment of the actuation member  60  to the release member  270 , in the present example the release member  270  includes a central axial bearing surface within which the actuation member  60  is rotationally received. The central axial bearing surface of the release member  270  includes an axial bore  275  in the release member  270 . The distal end of the actuation member  60  is received within and extends within the bore  275 . The bore  275  has a narrowed portion  277 , which may be located at a proximal end of the bore  275 . The actuation member  60  has a widened part  62 , which is located distally with respect to the narrowed portion  277  of the bore  275 . Note that, in common with the embodiment described above in relation to  FIGS. 1 to 12 , the head part  40 , including the release member  270 , is operable to rotate under the action of the driveline  30 , while the actuation member  60  remains substantially stationary. 
     In use, when the actuation member  60  is withdrawn proximally within the driveline  30  as noted above (see the arrows labelled A, B and C in  FIGS. 2A and 6 ), the widened part  62  of the actuation member  60  urges against the narrowed portion  277  whereby the release member  270  is moved proximally (e.g. against the bias provided by the biasing element (e.g. the helical spring  310 )). 
     The release member  270  may include jaw parts  276 ,  278  for defining spaces  284 ,  286 ,  288 ,  290 . The spaces  288 ,  290  are axially aligned with the spaces  208 ,  210  and with the spaces  229 , thereby to accommodate the connection member  111  when the connection member  111  is received within the spaces  208 ,  210 ,  229 . The spaces  284 ,  286  are axially aligned with the spaces  204 ,  206 , thereby to accommodate the connection member  110  when the connection member  110  is received within the spaces  204 ,  206 . 
     The release member  270  includes two laterally facing, substantially flat outer surfaces  274  provided on opposite sides of the release member  270 . Each surface faces toward a respective one of the jaw members  220 . Each surface is provided with a ramp. Each ramp includes a ramped surface  272  and an edge that forms a retaining surface  273  at one end of the ramped surface  272 . The ramped surfaces  272  rise at an oblique angle from the substantially flat outer surfaces  274  upon which the ramps are located. The ramp may form a wedge shape. With reference to  FIGS. 19 , an inwardly facing surface  262  of each jaw member  220  includes a catch  306 , which extends inwardly toward the release member  270 . Each catch  306  has a ramp engaging surface  304 , a rounded surface  308  and a locking surface  302 . The locking surface may extend substantially orthogonally with respect to the ramp engaging surface  304 . As can be seen from, for example,  FIG. 20 , each catch  306  extends through an opening  240  in one of the substantially flat outer lateral surfaces  248  of the housing  200 . This allows the catches  306  of the jaw members  220  to interact with the ramps of the release member  270 . This interaction will now be described with reference again to  FIGS. 14A-C ,  17 , and  19 - 21 . 
     When the jaw members  220  are in the first position ( FIG. 14A ), the ramp engaging surface  304  rests at the bottom of the ramp. As the jaw members  220  begin to rotate from the first position to the second position ( FIG. 14B ), the ramp engaging surfaces  304  of each catch  306  begins to ride along the ramped surfaces  272 . As can be seen in  FIG. 21 , the release member  270  comprises two cantilevered parts  281  formed by undercuts  279 . The ramps are located on the cantilevered parts. As the ramp engaging surfaces  304  of each catch  306  ride along the ramped surfaces  272 , this deflects the ramps, and consequently also the cantilevered parts  281  inward, toward the axis  201 . The cantilevered parts  281  resiliently resist this inward deflection and urge outwardly against the catches  306 . When the ramp engaging surfaces  304  reach the ends of the ramped surfaces  272 , the cantilevered parts  281  are longer restrained by the inward pressure of the catches  306 , and return to the non-deflected position shown in  FIG. 21 . At this point, in which the jaw members  220  have now reached the second position ( FIG. 14C ) the locking surfaces  302  of each catch  306  engage with the retaining surfaces  273  located at an ends of ramped surfaces  272 . This prevents the jaw members  220  from moving from rotating away from the second position (e.g. under the biasing force provided by the optional biasing element (e.g. leaf spring  260 ) described above. Accordingly, the ramps form catches, for engaging with a respective catch  306  of each jaw member  220  to lock the jaw members  220  in the second position. 
     To release the jaw members  220  from the second position for disconnecting the surgical rotational tool from the surgical rotational tool driver  10 , the actuation member  60  may be withdrawn proximally within the driveline  30  as described above. This may be achieved using the features of actuation mechanism described above in relation to  FIGS. 10-12  (as mentioned previously, the components of the surgical rotational tool driver  10  located proximally with respect to the distal shaft section  12  shown in, for example,  FIG. 13 , may be the same as described above in relation to  FIGS. 1 to 12 ). The proximal withdrawal of the actuation member  60  causes the release member  270  to slide proximally, against the bias provided by the biasing element (e.g. helical spring  310 ) in the housing  200 . With reference to  FIG. 22  (which shows the housing  200  and the release member  270  with the release member  270  in its non-withdrawn, resting position) and  FIG. 23  (which shows the housing  200  and the release member  270  with the release member  270  in its withdrawn position), this has the effect of moving the ramp proximally so that the locking surface  302  of the each catch  306  disengages from the retaining surface  273  of its respective ramp. With the locking surfaces  302  disengaged from the retaining surface  273 , the jaw members  220  are free to rotate back to the first position (e.g. under the biasing force provided by the biasing element (e.g. leaf spring  260 )). This allows the connection member  111  to be released from the spaces  229  defined by the jaws  222 ,  224 , thereby allowing disconnection of the surgical rotational tool from the surgical rotational tool driver  10 . 
     With reference to  FIGS. 17 to 20 , it is noted that an edge of the openings  20  may each include a detent  242 . The detent  242  may be located on distally located edge of each opening  20 . This optional detent  242  may be provided in some embodiments, for the purpose of retaining the jaw members  220  in the first position for receipt of the connection member  111  within the jaws of each jaw member  220 , prior to the attachment of the surgical rotational tool to the surgical rotational tool driver  10 . This may ensure that the surgical rotational tool driver  10  is ready to be connected to the surgical rotational tool during use. 
     In particular, the detent  242  can serve to prevent inadvertent rotation of the jaw members  220  away from the first position (i.e. prior to the receipt of the connection member  111  within the spaces  229  defined by the jaws  222 ,  224 ) by providing a barrier to the free movement of the catches  306  of the jaw members  220  within the openings  20 . 
     The detents  242  may be shaped and configured (e.g. made relatively shallow) such that the forces applied to the jaw members  220  when the connection member  111  is received within the spaces  229  (e.g. as the connection member  111  urges against the substantially flat inner surface  228 ) allows the catches  306  to overcome the detents  242 , allowing the jaw members  220  to rotate into the second position as described previously. 
     The detents  242  may for instance be provided in embodiments that do not include the previously discussed biasing element (e.g. elongate leaf spring  260 ) for biasing the jaw members toward the first position. However, and as shown in the figures, it is envisaged that the detents  242  may also be present in in embodiments that do include the biasing member. 
     A surgical rotational tool driver according to an embodiment of this invention may be included in a surgical kit. The kit may also include one or more differently sized acetabular reamers  100  connectable to the head part of the driveline of the surgical rotational tool driver. 
     A method of operating a surgical rotational tool driver  10  of the kind described above in relation to  FIGS. 13 to 25  includes connecting the connection features of the head part  40  of the driveline  30  of the surgical rotational tool driver  10  to a connection member (e.g.  110  and/or  111 ) of the surgical rotational tool (which may be an acetabular reamer  100  as noted above). The method also includes operating the release mechanism by sliding the release member  270  within the housing  200 . As described above, this may include withdrawing the actuation member  60  proximally within the driveline  30 . The method further includes removing the surgical rotational tool from the surgical rotational tool driver  10 . 
     The method may also include riding the catches  306  of the jaw members  220  along the respective ramped surfaces  272  extending laterally from the release member  270  as the jaw members  220  pivot from the first position to the second position and engaging the catches  306  of the jaw members  220  with retaining surfaces  273  located at an ends of the respective ramped surfaces  272  when they reach the end of the respective ramped surfaces  272 , to lock the jaw members  220  in the second position. 
     The method may further include sliding the release member  270  (e.g. by withdrawing the actuation member  60  proximally within the driveline  30 ) within the housing  200  to disengage the catches  306  of the jaw members  220  from the retaining surfaces  273  of the respective ramped surfaces on the release member  270 . 
     The method may also include sliding the release member  270  along a direction substantially parallel to the axis of rotation  201  of the head part  40 . 
     Accordingly, there has been described a surgical rotational tool driver and method. The driver includes a driveline extending within a hollow shaft and a head part including connection features for connecting to a connection member of a surgical rotational tool. The connection features of the head part include a housing and a pair of jaw member each including jaws for receiving the connection member. Each jaw member is pivotally mounted for rotation between: a first position for receipt of the connection member and a second position for retaining the connection member. The connection features of the head part further include a locking mechanism including a pair of catches for engaging with a respective catch of each jaw member to lock the jaw members in the second position. The locking mechanism also includes a release member slideably moveable within the housing to release the catches of the locking mechanism from the catches of the jaw members. 
     Although particular embodiments of the invention have been described, it will be appreciated that many modifications/additions and/or substitutions may be made within the scope of the claimed invention.