Abstract:
A method of placing screws into bone or tissue structure during a medical procedure uses a power driven screw driver, a fastener carrier with a series of fasteners temporarily attached thereto and an elongated band structure carried by the fastener carrier system for positioning and advancing the individual fasteners of the series of medical fasteners in a controlled manner to a position to receive a driving tip on the powered screw driver. Activating a trigger mechanism causes the tip of the screw driver to extend and interlock with the head of the fastener temporarily held in the band, removing the fastener from the band, rotating the driver tip and fastener for driving the fastener into a tissue or bone structure, and releasing the trigger following positioning of the fastener in the bone or tissue disconnects the screw driver tip from the fastener head, retracts the screw driver tip from the band and causes the fastener carrier system to advance forward to position a subsequent fastener in a location for grasping by the screw driver tip.

Description:
The present invention is generally directed to methods for the use of a fastener and drive system. The fastener and drive system comprises a driving tool and fasteners fed from a cartridge removeably attached to the driving tool and includes a feed system to position the fastener adjacent the active driving portion of the drive system. More specifically, the fastener and drive system is designed for placing screw fasteners into bones during a medical procedure and particularly for the placement of very small fasteners in cranial maxillo-facial procedures and reconstruction of bone supported anatomical features. 
     BACKGROUND 
     Surgical reconstruction of hard tissue, such as the placement of prosthetics, the repositioning and attachment of fractured bones and the addition of metallic support plates to repaired bone typically require the placement of fasteners, which may be adhesives, mechanical devices, or combinations thereof. In many instances the fastening system includes screws, which may have special thread and head designs adapted for the particular application or the placement system. These screws are often very small in size and therefore difficult to handle, position and thread into the underlying structure and can easily be dropped into the surgical cavity if they are being manually manipulated. 
     Systems comprise manual screw drivers or, more recently, cordless, battery powered drivers, to transmit a rotational driving force to screws, which may have specialized heads to match the driver tips. Because a typical procedure may require placement of numerous screws (20-60) the powered drivers are now preferred. A typical power driver is a reusable pencil grip instrument with a replaceable, single use, sterile, disposable battery pack. However, hospital personnel must still perform the tedious task of attaching each screw to the tip of the screwdriver or into a retaining structure on the tip and then handing it to the surgeon or manually loading a feeding system adapted to place the screw in front of the driver tip. The screw head has a recessed structure, such as a slot or a recessed geometric structure for example, cruciform, Phillips, square, hexagonal or exalobe shaped holes, for torque transmission from a matching structure on the tip of the driver. For torque transmission and to limit the tip from disengaging from the structure in the screw head the tolerances of the fit between the tip and the screw head construction are minimal and in some instances tapered to provide secure engagement (U.S. Pat. No. 4,269,246 to Larson et al.) 
     There are numerous publications and patents which show devices that relate to the field of the invention. They are directed to the placement of, or automatic delivery of, fasteners to a particular location and systems for driving the fasteners. The following are merely representative of the art; there are others which are primarily repetitive of those discussed herein. Many are for industrial applications and can not meet the needs of a surgeon for use in an enclosed, sterile environment and do not lend themselves to automatic one hand operation. Systems for delivering a fastener to the operative, rotating tip of a screw driver include:
     a) Non-Banded Delivery—U.S. Pat. No. 3,946,926 to Willis is an example of a pneumatic or strictly mechanical delivery of fasteners from a hopper. U.S. Pat. No. 4,408,877 to Lindmo et al. appears to cover loose screws fed along a track disposed in front of the screwdriver tip.   b) Stacked Fasteners—U.S. Pat. No. 5,590,574 to Lide is an example of a system that provides a linear arrangement of fasteners stacked head to tail inside the screwdriver.   c) Vertical Band—There are numerous patents to systems in which the fastener (nail or screw) lies across the face of a band and are attached to the band by notches or loops extending from the surface of the band. Alternatively the band may have a thickness so that the fastener can be inserted in a hole which extends through the band from one edge to a parallel opposite edge, for example, U.S. Pat. Nos. 5,758,768, 5,622,024, 5,469,767, and 4,930,630 to Habermehl as well as numerous other Habermehl patents. However, they all appear to use a band which attaches to the side of the fastener and which places the band in a plane coextensive with the axis of the screwdriver.   d) Horizontal Band—There are numerous patents that are directed to systems in which the screw is placed through a hole in the surface of the band with the band resting somewhere along the length of the shank of the screw or just below the head of the screw. These include US Patents to Chen (U.S. Pat. No. 5,522,687), Dohi (U.S. Pat. No. 5,544,746), Hon (U.S. Pat. No. 5,509,768), Huang (U.S. Pat. Nos. 5,931,298, 5,803,691, 5,788,445, 5,779,420), Lejdegard (U.S. Pat. No. 4,018,334), Lin (U.S. Pat. No. 5,775,514), and Shinjo (U.S. Pat. Nos. 5,984,096 and 6,761,268) all of which show various band designs which include extensions created from or formed below the surface of the band designed to grip the shaft of the screw.   

     Other patents are directed to the surgical fasteners and the design of the head of the fastener and drivers constructed to work with these fasteners or hold the fastener during the placement procedure. None of these patents include automatic delivery of the fasteners. 
     These prior devices do not provide the ease of operation and the ability to continuously and rapidly place numerous screws into the bone structure while minimizing the risk of loss of the screws during the procedure and the amount of time necessary to prepare the tool and the fasteners for use in the surgical procedure. These deficiencies were addressed in applicant&#39;s U.S. Pat. No. 7,406,899, incorporated herein in its entirety by reference. 
     SUMMARY 
     A method is described for placement of fasteners, namely screws, for medical applications which utilizes an automatic delivery system for the fastener and a drive system, preferably powered by replaceable or rechargeable batteries, for automated and continuous delivery and placement of the fasteners from a reloadable cartridge. 
     Activating a trigger mechanism causes the tip of the screw driver to extend and interlock with the head of the fastener temporarily held in the band, removing the fastener from the band, rotating the driver tip and fastener for driving the fastener into a tissue or bone structure, and releasing the trigger following positioning of the fastener in the bone or tissue disconnects the screw driver tip from the fastener head, retracts the screw driver tip from the band and causes the fastener carrier system to advance forward to position a subsequent fastener in a location for grasping by the screw driver tip. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective side view of a first embodiment of a fastener placement system incorporating features of the invention. 
         FIG. 2  is a side view of the screw delivery portion of the fastener placement system of  FIG. 1 . 
         FIG. 3  is a perspective view of the lower side of the embodiment of  FIG. 2  showing the fasteners in a carrying strip. 
         FIG. 4  is a perspective cutaway side view of the embodiment of  FIG. 2  with screw fasteners placed in a band. 
         FIG. 5  is a side view of a first embodiment of a screw fastener for use in the fastener placement system. 
         FIG. 6  is a cross sectional view of the screw of  FIG. 5  taken along line  6 - 6  of  FIG. 5 . 
         FIG. 6   a  is an enlarge view of the circled portion of  FIG. 6 . 
         FIG. 7  is a top view of the screw of  FIG. 5  showing a first embodiment of structure in the screw head to receive a matching driver tip. 
         FIG. 8  is a side view of a driver tip designed to interact with the screw head embodiment of  FIG. 7 . 
         FIG. 9  is an end view of the driver tip of  FIG. 8 . 
         FIG. 10  is a top perspective view of the screw of  FIG. 5  mounted in a first embodiment of a screw feeding band. 
         FIG. 11  is a bottom perspective view of the band of  FIG. 10 . 
         FIGS. 12-12   d  show several embodiments of screw retaining configurations as part of holes in a screw feeding band. 
         FIGS. 13   a  and  13   b ,  14   a  and  14   b ,  15   a  and  15   b , and  16   a  and  16   b  show several additional embodiments of screw head constructions which provide structure within the screw head for grasping the fastener. 
         FIGS. 17   a, b  and  c ,  18   a, b  and  c ,  19   a, b  and  c ,  20   a, b  and  c , and  21   a, b  and  c  are top, longitudinal cross sections and side views respectively of five embodiments of different hole structure in the head of the fastener as well as an external taper for external grasping of the fastener. 
         FIG. 22  is a perspective side view of a driver tip holding one of the embodiments of  FIGS. 17-21 . 
         FIGS. 23   a  and  b ,  24   a  and  b ,  25   a  and  b , and  26   a  and  b  are top and cross-sectional views respectively of further embodiments of the fastener including extensions from the head of the fastener in place of holes in the head. 
         FIG. 27  is a bottom perspective side view of the screw delivery portion showing the track for mounting the replaceable cartridge assembly. 
         FIG. 28  is a top perspective view of the screw delivery portion showing the tape receiving rack with the advancement trigger removed. 
         FIG. 29  is a longitudinal cross section view of the drive portion of the fastener placement system of  FIG. 1 . 
         FIG. 30  is a cutaway side view of the driver tip inserted into the head of the fastener of  FIG. 5 . 
         FIG. 31  is a perspective view of an alternative band structure for holding the fasteners. 
         FIG. 32  is a perspective side view of a second embodiment of a fastener placement system incorporating features of the invention. 
         FIG. 33  is a side view of the screw delivery portion of the fastener placement system of  FIG. 32 . 
         FIG. 34  is a perspective view of the lower side of the embodiment of  FIG. 32  showing the fasteners in a carrying strip. 
     
    
    
     DETAILED DESCRIPTION 
     The fastener and driver disclosed herein, referred to in combination as a fastener system, is primarily intended for use in medical procedures which require the placement of small surgical screws, such as would be used in a cranial maxillo-facial procedures, prosthetic or an orthopedic procedure, which are automatically positioned and held in front of the tip of the screwdriver so that multiple screws can be placed in a serial manner by a one hand operation. 
     The fastener system includes an automatic finger activated driver having a tip which rotates around its central, longitudinal axis by an electrical drive means, such as rechargeable or replaceable batteries. While less preferred, the driver may alternatively be driven by external AC or DC power sources, or pneumatic or hydraulic drives. As a still further alternative gas cylinders inserted in the driver handle instead of batteries can be used to provide a replaceable or rechargeable drive system. As a still further alternative, the rotating tip can be driven by a negative pressure provided by an external vacuum source. 
     A feature of the system described herein is a fastener head construction and a driver tip configuration which allows the driver tip to be inserted into a depression in the head of the fastener or grasp the outer edge of the head, while at the same time separating the fastener from a carrier strip. This eliminates the task of manually mounting the fastener on the driver tip. The fastener can then be readily transported to the surgical placement site without fear of dropping the fastener and driven into the bone at the surgical placement site. The driver tip is then retracted, leaving the fastener in place in the bone and a subsequent fastener automatically moves into position in front of the driver tip to repeat the procedure. 
     A preferred embodiment uses a replaceable cartridge which includes an elongated band with multiple fasteners inserted centrally along the length of the band. The fasteners are held in the band by structure integral with the edges of holes in the band, the structure gripping the edge of the head of the fastener. However, other band structures or different retaining structures can be used to hold and place the fasteners in front of the driver tip. Still further, different means, such as a hopper containing fasteners can be used to funnel individual fasteners, one at a time, to a point in front of the driver tip where they are temporarily held until the driver tip locks into or onto the fastener head. 
     One skilled in the art, based on the disclosure set forth herein, can design other techniques to carry the fastener to a point in front of the driver tip for placement of the tip in the fastener head ready for driving into the surgical site. 
     In a first embodiment multiple screws are temporarily attached along the length of a band. The screw delivery system includes a removable and replaceable cartridge structure to enclose the band of screws and a track for the band of screws to travel along for placement in front of a screw driver tip. Each successive screw on the band is serially positioned in front of the tip of the screw driver tip. A trigger mechanism causes the band to move forward in front of the tip, placing the fastener in the right position to be engaged by the driver tip. The driver tip includes an enlarged portion which is inserted into the head of the screw or around the head of the screw so that when the screw is separated from the band the screw is retained on the tip by interlocking structures. Moving the tip forward engages the screw head, separates the screw head from the band, inserts pins on the tip or other geometric shapes into or around matching shapes in the fastener head, and provides rotary motion to the screw so that it can be driven into a target surface. This is accomplished by rotating the tip within the driver while the screw driver handle is held fixed (not rotated). 
     A perspective side view of a first embodiment of a fastener placement system  10 , comprising a screw delivery portion  12  and a driver assembly  14  is shown in  FIG. 1 . The screw delivery portion  12 , as best shown in  FIGS. 2-4 , comprises a cylindrical shell  16  which has a central, longitudinal opening  18  designed to receive and retain the driver assembly  14 . A removable cartridge  20  carrying fasteners  22  is attached to a receiving track  21  on the lower surface of the cylindrical shell  16 . The cartridge walls are preferably transparent so the user can see the quantity of fasteners remaining in the cartridge. The removable cartridge  20  is preloaded with a moveable strip  26  which carries the fasteners  22 . Upon assembly for use the moveable strip  26  is extended from the removable cartridge  20  along the front portion  28  of the cylindrical shell  16 , across the tip  30  of the shell  16  and rearwardly across the upper region of the front portion  28  where it is moveably connected to a trigger  32 . 
     As shown in  FIGS. 2 and 3 , the fasteners  22  are temporarily and removeably attached to the elongated band or strip  26  such as shown in  FIG. 10 . The strip extends rearwardly beyond the last fastener  22  to provide a tail  23  for extending into the cartridge  20 . A leading end  24  of the strip  26  extends forward from the front most fastener so that the strip  26  can be engaged with the under side of the trigger  32 . In a preferred embodiment at least 10 fasteners  22  are attached and evenly spaced along the central portion of the strip  26 . The attachment must be such that the fasteners  22  will remain in position on the strip  26  through assembly, packaging and transportation of the removable cartridge  20 , installation of the cartridge  20  onto the cylindrical shell  16  and placement of the loaded strip across the tip  30  as well as movement across the front portion  28  of the cylindrical shell  16 . The attachment must also be sufficient so that the driver tip  34  can engage with the head  36  of the fastener as the driver tip  34  is advanced forward. However, the temporary connection between the fastener  22  and the moveable strip  26  must also be readily disrupted thereafter by the further forward movement of the driver tip  34 , the fastener  22  now temporarily and removeably carried by the driver tip  34 . Typically, the fastener  22  is held in the strip  26  by a friction fit and/or horizontal or vertical extensions from the edge of mounting holes  38 . Alternatively, a biocompatible glue or adhesive (not shown) could be used to temporarily secure the fastener  22  to the band  26 . 
     A particular embodiment illustrated in the drawings includes a hole  38  in the band with two lobes  40  extending outward from the edge of the band  26  partly across the opening of the hole  38  and two tabs  42  extending into the hole and downward from the surface.  FIG. 11  is a bottom perspective view of a portion of the band or moveable strip  26  showing the tabs  42 . Examples of alternative designs are shown in  FIG. 12   a - 12   d  where a row of snowflake shaped openings are shown stamped or chemically etched into the band  26 . In  FIG. 12   b  one of the holes  38  is shown in its initial form (circled portion I) while another hole  38  (circled portions II of  FIG. 12   b  demonstrates the bent down tabs  42  with inward extending lobes  40 .  FIG. 11   c  shows the embodiment of  FIGS. 10 and 11 .  FIG. 12   a  shows an example of leaf spring structures  44  cut from the edge of the hole  38 . The leaf spring structures  44  have a portion attached to the edge of the hole and one or two ends extending across the opening of the hole  38  to provide a spring-like grip against the side of the head  36  of the fastener  22 . One skilled in the art will recognize that numerous different structures can be provided to grip the head  36  of the fastener  22 . 
     Referring back to  FIG. 4 , the tail  23  on the band  26 , with fasteners  22  attached to the band, extends into the cartridge  20  and through a tensioning means  46  within the cartridge. Alternatively, the tail  23  can be attached to a reel or spool which includes a tensioning spring (not shown). The band then passes over first and second guide rollers  48 ,  50  and behind guiding pins  52  which extend from the inner wall  54  of the cartridge  20  over the edge of the strip  26 , but not far enough to contact the fasteners  20 . The forward-most fastener  22  is positioned in front of the cylinder tip  30  and the leading end  24  of the strip  26  is passed under and is engaged with the trigger  32  so that when the trigger  32  retracts during use the band is moved forward placing the next available fastener  22  in position on the cylinder tip  30 . 
       FIG. 1  is a perspective side view and  FIG. 29  is a longitudinal cross-sectional view of an embodiment of the fastener placement system  10  showing the driver assembly  14  within the screw delivery portion  12 . Included within the screw delivery portion  12  is a power source, preferably a rechargeable or replaceable battery  56  which drives a motor  57 , gear box  107  and drive transmission coupling  207  which in turn provides rotary motion to the driver tip  34 . The motor  57  and gear assembly can include a reversing means so the tip can be rotated to insert or remove the fastener from the target bone surface. Also included are means for operatively connecting the trigger  32  on the cylinder  16  so that moving the trigger forward (toward the tip  34 ) also moves the driver tip  34  forward. When the trigger  32  is released a spring mechanism  58  causes the driver tip  34  to retract and, at the same time advance the strip  26 , positioning the next fastener  22  for use. A separate spring (not shown) causes the pin  68  to retract. 
       FIGS. 5-7  show a preferred embodiment of the fastener  22  for use with the fastener placement system  10 . The threaded portion  60  is similar to that on threaded fasteners currently used for medical applications. The head  36  of the fastener  22  has a recessed surface  62  which includes two radially spaced holes  64  extending perpendicular to the recessed surface  62 . These holes are sized to receive two like-sized and shaped driver pins  68  which extend from and retract into the driver tip  34 . While the driver pins  68  are preferably sized and shaped like the holes, they can be of any shape as long as they fit in the holes. Also, the holes  64  do not have to be round but can be of any shape and in fact can each be a different shape. The wall of the head  36  of the fastener  22  extending above the recessed surface  62  has a taper  66  extending inwardly from the top down, as best shown in  FIG. 6   a .  FIGS. 8 and 9  show a similar shaped outwardly extending portion or flange  70  on the driver tip  34 . The flange  70 , being slightly larger then the top of the taper  66 , allows the driver tip  34  to be inserted into the head of the fastener  22  and grasp the fastener head  36 , interlocking with the head  36  of the fastener  22 , as shown in  FIG. 30  to separate the fastener from the strip  26 . 
     To use the fastener placement system  10  a loaded cartridge  20  is slid into track  21  on the lower wall of the cylindrical shell  16 , the moveable strip  26  is placed over the front portion  28  and across the tip  30 . A first fastener  22  is positioned extending outward from the tip  30 . The leading edge  24  is fed under the trigger  32 . The trigger  32  is manually advanced toward the tip  30 , which causes power from the battery  56  to be delivered to the motor  57 , causing the tip  34  to rotate and to move forward toward the fastener head  36 . Continued forward movement causes the flange  70  to enter the head of the fastener and interlock with the taper  66  while at the same time the driver pins  68  are extended into the holes  64  in the head of the fastener  22 . Substantially simultaneously with the flange  70  and taper  66  grasping each other and the pins  68  entering the holes  64  the fastener  22  becomes detached from the strip  26 . The driver tip  34 , with the rotating fastener  22  attached thereto, now extends through the mounting hole  38  and the rotating fastener  22  can be applied to the bone surface for securing the bone pieces together. Releasing the trigger  32  allows spring  58  to exert rearward motion on the driver tip  34 . The separate springs (not shown) also cause the pins  68  to retract, the driver tip  34  to separate from the fastener head  36  and the rotation of the driver tip  34  to cease. As the trigger moves back to its resting position extensions on the bottom of the trigger (not shown) set into drive holes  72  spaced along the edge of the band  26 , grasping the band and causing the leading edge  24  to move rearward, which positions the next fastener  22  in front of the cylinder tip  30  and driver tip  34  so that the above described action can be repeated. 
     While the above described embodiment describes two pins  68  that insert into holes  64  in the fastener head  36  one or more geometric shaped holes or slots in the head of the fastener  22 , and matching structure on the driver tip  34  can be used to accomplish the same screw placement function. Alternative interacting hole or holes  64  and driver tip  34  include numerous common structures used on the head of screws and bolts including but not limited to Phillips head, Allen wrench, slots and other geometric shapes as shown in  FIGS. 12-21   a .  FIGS. 13-16  show some alternative designs for the fastener head structure. While  FIG. 7  shows a circular top inner edge on the recess, other non-circular or modified circular designs may be used.  FIGS. 13-16   a  and  b  are top and cross-sectional views of four alternatives.  FIGS. 16   a  and  b  show a fastener  34  with a round, serrated edge  67  to aid in grasping the fastener for rotation.  FIGS. 13   a  and  b  show an upper inner edge with six sides, but other geometric shapes can be used.  FIGS. 14 and 15  show rounded variations of the design of  FIG. 13 . 
       FIGS. 17-21   a, b  and  c  show top, cross sectional and side views of five alternative embodiments with different shaped hole  64  structures in the head  36  of the fastener  22 . As best shown in  FIGS. 17-21   c , these fasteners  22  also have a taper  66  on the outer surface of the head  32  which can be grabbed by inwardly extending portion  74  on a driver tip  34  as shown in  FIG. 22 .  FIGS. 23-26   a  and  b  are top and longitudinal cut-away views of still further embodiments which show extensions  76  from the head  36  of the fastener. The driver pins  68 , instead of sitting into holes  64  in the head  36  of the fastener  22  are structured to grasp or surround the extensions  76 . One skilled in the art will recognize that a combination of holes  64  and extensions  76  can also be used. 
       FIG. 31  shows an alternative band  126  which has an upper band  128 , which holds the fastener  22  in a manner as described above, and a lower band  130  to aid in aligning the fastener. The lower band  130  also has holes there through which have a diameter greater than the head  36  of the fastener  22  so the fastener will pass through without bending. Also shown is the driver tip (with the cylindrical shell  16  not shown). The upper band  128  and lower band  130  are connected by posts  132 . To allow the two layer band to wrap around curves, the lower band  130  has slits  134  across the width. 
       FIG. 32  is a perspective side view of a second embodiment of a fastener placement system  100 , comprising a screw delivery portion  102  and a driver assembly  104  is shown in  FIG. 32 . The screw delivery portion  102 , also shown in  FIGS. 33 and 34 , comprises a cylindrical shell  106  which has a central, longitudinal opening  108  designed to receive and retain the driver assembly  104 . A removable cartridge  120  carrying fasteners  122  is attached to a receiving track  121  on the lower surface of the cylindrical shell  116 . The cartridge walls are preferably transparent so the user can see the quantity of fasteners remaining in the cartridge. The removable cartridge  120  is preloaded with a moveable strip  126  which carries the fasteners  122 . Upon assembly for use the moveable strip  126  is extended from the removable cartridge  20  along the front portion  128  of the cylindrical shell  116 , across the tip  130  of the shell  116  and rearwardly across the upper region of the front portion  128  where it is moveably connected to a trigger  132 . One difference between the embodiment of  FIG. 32  and the embodiment of  FIG. 1  is that the second embodiment has the trigger  132  located on the right side of the device. This was found to be more ergonomically favorable for operation then the top mounted trigger  32  of the first embodiment, particularly for a right handed operator. A further embodiment with the trigger on the left side for use by left handed individuals (not shown) can also be provided or the trigger  132  can be constructed with both a right and a left side trigger which provides ease of operation using either the right or the left hand. 
     As shown in  FIGS. 33 and 34 , the fasteners  122  are temporarily and removeably attached to the elongated band or strip  126  in the same manner as shown in  FIG. 10 . The strip extends rearwardly beyond the last fastener  122  to provide a tail (not shown) for extending into the cartridge  120 . A leading end  124  of the strip  126  extends forward from the front most fastener so that the strip  126  can be engaged with structure attached to the trigger  132  within the fastener placement system  100 . In a preferred embodiment at least 10 fasteners  122  are attached and evenly spaced along the central portion of the strip  126 . The attachment must be such that the fasteners  122  will remain in position on the strip  126  through assembly, packaging and transportation of the removable cartridge  120 , installation of the cartridge  120  onto the cylindrical shell  116  and placement of the loaded strip across the tip  130  as well as movement across the front portion  128  of the cylindrical shell  116 . The attachment must also be sufficient so that the driver tip (not shown) can engage with the head  36  of the fastener  122  as the driver tip is advanced forward. However, the temporary connection between the fastener  122  and the moveable strip  126  must also be readily disrupted thereafter by the further forward movement of the driver tip, the fastener  122  now temporarily and removeably carried by the driver tip. Typically, the fastener  122  is held in the strip  126  by a friction fit and/or horizontal or vertical extensions from the edge of mounting holes  38 . Alternatively, a biocompatible glue or adhesive (not shown) could be used to temporarily secure the fastener  122  to the band  126 . Other components of the second embodiment not shown in  FIGS. 32-34  are the same as in the first embodiment. 
     To use the fastener placement system  100  a loaded cartridge  120  is slid into track  121  on the lower wall of the cylindrical shell  116 , and the moveable strip  126  is placed over the front portion  128  and across the tip  130 . A first fastener  122  is positioned extending outward from the tip  130 . The leading edge  124  is fed under a retainer clip  150 . The trigger  132  is manually advanced toward the tip  130 , which causes power from the battery  56  to be delivered to the motor  57 , causing the tip  134  to rotate and to move forward toward the fastener head  36 . Continued forward movement causes the flange  70  to enter the head of the fastener  122  and interlock with the taper  66  while at the same time the driver pins  68  are extended into the holes  64  in the head of the fastener  122 . Substantially simultaneously with the flange  70  and taper  66  grasping each other and the pins  68  entering the holes  64  the fastener  122  becomes detached from the strip  126 . The driver tip  34 , with the rotating fastener  122  attached thereto, now extends through the mounting hole  38  and the rotating fastener  122  can be applied to the bone surface for securing the bone pieces together. Releasing the trigger  132  allows a spring to exert rearward motion on the driver tip  134 . The separate springs (not shown) also cause the pins  68  to retract, the driver tip  34  to separate from the fastener head  36  and the rotation of the driver tip  34  to cease. As the trigger  132  moves back to its resting position extensions from the trigger (not shown) interact with drive holes  72  spaced along the edge of the band  126 , grasping the band and causing the leading edge  124  to move rearward, which positions the next fastener  122  in front of the tip  130  and driver tip  34  so that the above described action can be repeated.