Patent Publication Number: US-2004059341-A1

Title: Bone anchor placement device with recessed anchor mount

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     [0001] This is a continuation-in-part of U.S. patent application Ser. No. 09/309,816, filed on May 11, 1999, which claims priority to U.S. Provisional Patent Application Serial Nos. 60/085,113, filed May 12, 1998, and 60/125,207, filed Mar. 18, 1999. This is also a continuation-in-part of U.S. patent application Ser. No. 09/238,654, filed on Jan. 26, 1999, which claims priority to U.S. Provisional Patent Application Serial No. 60/072,641, filed Jan. 27, 1998. 
    
    
     
       TECHNICAL FIELD  
       [0002] The invention relates generally to devices for placing bone anchors in bone, and in particular, to recessed bone anchor mounts used in connection with bone anchor drivers.  
       BACKGROUND INFORMATION  
       [0003] Urinary incontinence in women may be caused by urethral hypermobility, a condition in which the bladder neck and proximal urethra may rotate and descend in response to increases in intra-abdominal pressure. Hypermobility may be the result of aging, child delivery or conditions that weaken, stretch, or tear the muscles around the bladder, bladder neck and/or urethra. Urinary incontinence may also be caused by intrinsic sphincter deficiency (ISD), a condition in which the urethral sphincter does not coapt properly.  
       [0004] There are numerous approaches for treating urinary incontinence. In a bladder neck suspension procedure for treating hypermobility, sutures are placed around the muscle groups on either side of the urethra and are affixed to the pubic bone or other supporting structures to reposition and resuspend the proximal urethra. Also common are sling type operations, which may be performed to treat urethral hypermobility, intrinsic sphincter deficiency or both. In a sling type operation, a sling is placed under the urethra and bladder and is tensioned to elevate and stabilize the urethra, prevent excessive downward mobility, or compress the sphincter to treat intrinsic sphincter deficiency.  
       [0005] In these procedures, sutures are anchored to the supporting structures, such as the pubic bone, Cooper&#39;s ligament, or the rectus fascia. Bone anchor placement devices, such as bone anchor drivers, may be used to place bone anchors at selected insertion sites in the pubic bone. Sutures may then be attached to the bone anchors.  
       [0006] To reduce postoperative patient discomfort, transvaginal surgical procedures for bone anchor placement are preferred over percutaneous procedures, which require an incision in the abdominal wall (and sometimes the vaginal wall) to introduce a bone anchor placement device, and can be highly invasive and traumatic to the patient. In a transvaginal procedure, vaginal incisions are made and bone anchors or similar attachment devices are secured to the posterior side pelvic wall through the vaginal incision. While being guided to the desired locations, the anchor placement device passes through multiple layers of tissue. During this process, an unprotected bone anchor can catch, tear or scrape tissue, snap a surgeon&#39;s glove, or become dislodged.  
       [0007] It is desirable, therefore, to provide a protection mechanism for the bone anchor that prevents the sharp tip of the anchor from causing unintended tissue damage during passage of the anchor through tissue. At the same time, it is desirable that the head design for a bone anchor placement device be as compact as possible to minimize the necessary size of the vaginal incision through which the anchor placement device is inserted.  
       SUMMARY OF THE INVENTION  
       [0008] The present invention relates to manual bone anchor placement devices. The manual bone anchor placement devices disclosed herein are particularly useful in transvaginal methods of treating female urinary incontinence, although they can be used in other medical applications. The devices of the present invention are designed to permit rotational insertion of a bone anchor screw and to provide low cost alternatives to powered cannulated drills. The devices may be disposable or may be modular in nature, thereby allowing interchange of parts for reuse.  
       [0009] An advantage of the disclosed manual bone anchor placement devices is that they eliminate the need for a percutaneous incision to access an insertion area, although the devices can be used in a percutaneous procedure. A transvaginal approach to inserting a bone anchor screw into the pubic bone is far less invasive than a percutaneous procedure, thus a transvaginal procedure is far less traumatic for the patient.  
       [0010] An additional advantage of the disclosed manual bone anchor placement devices is that they seat a self-tapping bone anchor screw with a pre-attached suture. Since the bone anchor screw used with the disclosed devices is self-tapping and the suture is pre-attached, it is unnecessary for the physician to prebore a hole into the bone, remove the drill, introduce a seating device, seat the bone anchor screw, and then thread the suture. Single-step insertion of the bone anchor screw and suture not only reduces the total time required for the procedure, it also greatly reduces the possibility that the physician may lose access to the bored hole or seated bone anchor screw. Thus, the possible need to drill additional holes and/or seat additional bone anchor screws is reduced.  
       [0011] The manual bone anchor placement devices disclosed herein provide a mechanism to translate linear force exerted by a user on a lever into rotary force on a bone anchor screw. In one aspect of the invention, the manual bone anchor placement device includes a manually actuatable lever, a resilient element, a force translator, and a rotator. The force translator is coupled at its proximal end to the lever and at its distal end to the resilient element. The resilient element is coupled to the rotator. Linear force on the lever is transmitted through the force translator to the resilient element and from the resilient element to the rotator. The rotator rotates in response to this force. The device may further include a securing element coupled to the rotator that mates with a bone anchor screw and rotates when the rotator rotates, thereby applying a torque on the bone anchor screw and placing the bone anchor screw into bone.  
       [0012] In another aspect of the invention, the manual bone anchor placement device includes a manually actuatable lever, a force translator, a rack, and a rotator. The force translator includes a distal end and a proximal end, the proximal end receiving force from the lever, the distal end being coupled to the rack. The force translator transmits force to the rack, which moves linearly into an engaging position in response to this force. The rotator is positioned in close proximity to the rack for engagement with the rack when the rack moves into the engaging position. Engagement of the rotator by the rack causes the rotator to rotate. The device may further include a coupler coupled to the rotator that mates with a bone anchor screw and rotates when the rotator rotates, thereby placing the bone anchor screw into bone.  
       [0013] In another aspect of the invention, a manual bone anchor placement device is disclosed that includes a manually actuatable lever, a driver rod with threads, and a cup and washer positioned over the threads. The cup is coupled to the lever and moves axially along the driver rod upon actuation of the lever, engaging with the washer. When the cup and washer engage each other, linear force transmitted from the lever through the cup is translated to a rotary force on the driver rod, rotating the driver rod. The device may further include a coupling element for mating with a bone anchor screw and for rotating when the driver rod rotates to place the bone anchor screw into bone.  
       [0014] The present invention also relates to a self-tapping buttress-shaped bone anchor screw. The bone anchor screw of the present invention comprises a micropolished eyelet for receiving a suture. The eyelet may be circular, ellipsoidal, or teardrop shaped. The bone anchor screw described herein is designed to require less torque to seat and to minimize load on a pre-attached suture in comparison with known bone anchor screws.  
       [0015] Kits are also disclosed comprising any of: a molded flexible sleeve for enclosing a suture, a retaining clip for preventing the suture from slipping out of the sleeve, a buttress-shaped bone anchor screw comprising a micropolished eyelet for receiving a suture, and a suture which may, or may not, be pre-attached to the bone anchor screw. A collapsible, protective cover for a bone anchor screw is also disclosed.  
       [0016] In yet another aspect of the invention, the manual bone anchor placement device includes a head assembly, a recessed anchor mount movably disposed within the head assembly, and an actuation mechanism coupled to the recessed anchor mount. In various embodiments, the actuation mechanism can be a push wire or a pull wire, and the mechanism actuates the recessed anchor mount between a recessed position and an advanced position. The anchor mount can include an outer surface having at least one flat surface and the head assembly can have a core comprising a mating shape. Further, the manual bone anchor placement device can include a bone anchor releasably engaged to the anchor mount. In addition, the anchor mount can include a groove for accommodating a suture attached to the bone anchor.  
       [0017] In still another aspect of the invention, the manual bone anchor placement device includes a handle, a shaft extending in a distal direction from the handle, a head assembly disposed at a distal end of the shaft, a recessed anchor mount movably disposed within the head assembly, and an actuation mechanism coupled to the recessed anchor mount. In various embodiments, the actuation mechanism can be a push wire or a pull wire, and the mechanism actuates the recessed anchor mount between a recessed position and an advanced position. Further, the actuation mechanism can be situated within a channel disposed on the handle, an actuator disposed on the handle can operate the actuation mechanism, and the actuation mechanism may be manufactured of spring steel or nitinol. The anchor mount can include an outer surface having at least one flat surface and the head assembly can have a core comprising a mating shape. Further, the manual bone anchor placement device can include a bone anchor releasably engaged to the anchor mount. In addition, the anchor mount can include a groove for accommodating a suture attached to the bone anchor. Still further, the manual bone anchor placement device can include a stop disposed within the head assembly, for example within the core. Alternatively, the stop can be located on the actuation mechanism.  
       [0018] These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description of embodiments of the invention, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0019] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of the invention.  
     [0020]FIG. 1A is a perspective side view of a manual bone anchor placement device within the scope of the present invention. FIG. 1B shows a section of a side-view of the shaft of a manual anchor placement device to which a suture ring is clipped and through which a suture is threaded. FIG. 1C shows an enlarged cross-sectional view of a suture ring.  
     [0021]FIG. 2 shows a perspective side view of a manual bone anchor placement device according to one embodiment of the present invention. In this embodiment, the manual bone anchor placement device comprises a groove cut into the outer surface of the handle through which a suture is threaded and the shaft of the manual bone anchor placement is angled upwards at about a 90-degree angle.  
     [0022]FIG. 3A is a side view of a cross-section through a wrap-around manual bone anchor screw placement device according to one embodiment of the invention showing the components of an action mechanism and a wrap-around rotary force mechanism in which a resilient element is wrapped around a rotator. FIG. 3B is an enlarged perspective view of a connector and lever arrangement in an action mechanism according to one embodiment of the invention.  
     [0023] FIGS.  4 A- 4 D show views of the head end of a wrap-around manual bone anchor placement device according to different embodiments of the invention. FIG. 4A shows a cross-sectional view of an embodiment where the rotator includes a floating pawl. FIG. 4B shows an enlarged cross-sectional view of a rotator that has three floating pawls. FIG. 4C shows a three-dimensional cut-away view of the head end of the shaft in an embodiment of the invention where the rotator has two floating pawls. FIG. 4D shows a three-dimensional cut-away view of the head end of the shaft in an embodiment of the invention where the rotator has a single floating pawl.  
     [0024] FIGS.  5 A- 5 H show enlarged views of securing elements used with a wrap-around manual bone anchor placement device and bone anchor screws according to different embodiments of the invention. FIGS.  5 A- 5 D show enlarged views of a securing element that has a hex-shaped recess in its mating portion for mating with a bone anchor screw with a hex-shaped shaft at its base. FIG. 5A is a perspective view of the securing element showing the hex-shaped recess. FIG. 5B is a cross-sectional view through the engaging portion of the securing element. FIG. 5C is a perspective side-view of the securing element. FIG. 5D is a view from the top of the securing element. FIG. 5E shows a bone anchor screw that has a hex-shaped shaft at its base. FIG. 5F shows a perspective view of a securing element whose mating portion has a hex-shaped protrusion. FIG. 5G shows a perspective side view of a securing element whose mating portion has a hex-shaped protrusion. FIG. 5H shows an enlarged view of a bone anchor screw with a hex-shaped recess at its base for mating with a securing element whose mating portion has a hex-shaped protrusion.  
     [0025] FIGS.  6 A- 6 C show enlarged views of the rotatable housing used in a wrap-around manual bone anchor placement device. FIG. 6A shows a perspective view. FIG. 6B shows a side view. FIG. 6C shows a cross-sectional view.  
     [0026] FIGS.  7 A- 7 C show enlarged views of the floating portion of a floating pawl used in a wrap-around manual bone anchor placement device. FIG. 7A shows a perspective view. FIG. 7B shows a side view. FIG. 7C shows a cross-sectional view.  
     [0027] FIGS.  8 A- 8 C show enlarged views of the flat spring portion of a floating pawl used in a wrap-around manual bone anchor placement device. FIG. 8A shows a perspective view where the flat spring portion is slightly bent. FIG. 8B shows a side view of a flat spring portion that is slightly bent. FIG. 8C shows a perspective view where the flat spring portion is lying flat.  
     [0028]FIG. 9 shows an enlarged view of a resilient element used in a wrap-around manual bone anchor screw placement device.  
     [0029]FIG. 10 shows a schematic view of how force is transmitted through the resilient element in a wrap-around manual bone anchor placement device.  
     [0030]FIG. 11 shows a perspective view of a wrap-around manual anchor placement device according to one embodiment of the invention where the shaft and handle portions include interchangeable modules.  
     [0031] FIGS.  12 A- 12 I show enlarged views of a head module of a wrap-around manual bone anchor placement device according to one embodiment of the invention.  
     [0032]FIG. 13A shows an enlarged perspective view of a head module of a wrap-around manual bone anchor placement device according to one embodiment of the invention where a protective sheath is provided to protect the bone anchor screw and the portion of the securing element that protrudes from the head module. FIG. 13B shows an enlarged perspective view of a collapsible protective cover for a bone anchor screw. The left-hand side of the Figure shows the cover in an uncollapsed state. The right-hand side of the Figure shows the cover in a collapsed state. FIG. 13C shows an enlarged cross-sectional view of a collapsible protective cover surrounding a bone anchor screw. The left-hand side of the Figure shows the cover in an uncollapsed state and completely surrounding a bone anchor screw. The right-hand side of the Figure shows the cover in a collapsed state, exposing the bone anchor screw.  
     [0033]FIG. 14 shows an enlarged version of a securing element used in a wrap-around manual bone anchor placement device according to one embodiment of the invention where the mating portion of the securing element may be uncoupled from the engaging portion of the securing element.  
     [0034]FIG. 15 is a side view of a cross-section through a rack and rotator manual bone anchor placement device according to one embodiment of the invention, showing the components of an action mechanism and a rack and rotator rotary force mechanism.  
     [0035]FIG. 16 shows an enlarged view of a head assembly in a rack and rotator manual bone anchor screw placement device in which the rotator comprises a ratchet wheel.  
     [0036]FIG. 17 shows an enlarged view of a head assembly in a rack and rotator manual bone anchor placement device in which the rotator comprises a pinion.  
     [0037]FIGS. 18A and 18B show a side view of a cross-section through the handle and proximal portion of the shaft in a rack and rotator manual bone anchor placement device according to one embodiment of the invention. FIG. 18A shows an action mechanism that transmits a pull force on a force translator. FIG. 18B shows an action mechanism that transmits a push force on a force translator.  
     [0038]FIG. 19 shows an enlarged cross-sectional view of a head assembly in a rack and rotator manual bone anchor placement device according to one embodiment of the invention, in which linear force is transmitted to the rack through a rack spring and the rotator comprises a pinion. A bone anchor screw with a pre-attached suture is shown coupled to the pinion by a coupler. A protective cover covers the bone anchor screw. Dashed lines in the Figure show the portion of the bone anchor screw and pre-attached suture inside the coupler.  
     [0039]FIG. 20 shows an enlarged cross-sectional view of a head assembly in a rack and rotator manual bone anchor placement device according to one embodiment of the invention in which linear force is transmitted to the rack via wedge members.  
     [0040]FIG. 21 shows an enlarged cross-sectional view of a head assembly in a rack and rotator manual bone anchor placement device according to one embodiment of the invention in which linear force is transmitted to the rack by pneumatic or hydraulic force on a plunger.  
     [0041]FIG. 22A shows a cross-sectional sideview of a cup and washer manual bone anchor placement device according to one embodiment of the invention that includes a cup and washer rotary force mechanism. FIG. 22B shows a further embodiment of the invention in which a return coil spring is provided between the cup and washer assembly and the barrel end of the handle.  
     [0042] FIGS.  23 A- 23 D show enlarged views of a cup and washer assembly used in a cup and washer manual bone anchor placement device according to one embodiment of the invention. FIG. 23A shows a cross-sectional view of a driver rod with grooves to interface with protrusions on a washer. FIG. 23B shows a cross-sectional view of a washer with corresponding protrusions to interface with the grooves in the driver rod. FIG. 23C shows a perspective side view of a cup and washer assembly on a driver rod in which the washer is in a “free-floating” or non-engaged position. FIG. 23D shows a perspective sideview of a cup and washer assembly in which the washer is in an engaged position.  
     [0043]FIGS. 24A and 24B show enlarged views of a cup and washer assembly according to one aspect of the invention. FIG. 24A shows a cross-sectional view from one side of a cup and washer assembly positioned on a driver rod that includes a cover plate. FIG. 24B shows a cross-sectional view from the top of the cup and washer assembly.  
     [0044]FIG. 25A shows a section of a lead anchor screw and a coupling element used in a cup and washer manual bone anchor placement device according to one embodiment of the invention in which the coupling element has a recess through which the suture of a bone anchor screw is threaded. The Figure shows the suture partly pulled out of the recess. FIG. 25B shows a perspective view of the top of a cover plate used in a cup and washer assembly according to one embodiment of the invention. FIG. 25C shows a perspective view of the top of a washer used in a cup and washer assembly. FIG. 25D shows a perspective view of the top of a cup used in the cup and washer assembly (i.e., the side that faces the washer).  
     [0045]FIG. 26 shows a cross-section through a longitudinal axis of a self-tapping bone anchor screw according to one embodiment of the invention.  
     [0046]FIG. 27A is a side view of an alternate embodiment of an anchor placement device constructed according to the present invention.  
     [0047] FIGS.  27 B- 27 E are cross-sectional views of various embodiments of the shaft of the device of FIG. 27A as taken at A-A.  
     [0048]FIG. 28A is an enlarged perspective view of one embodiment of an anchor mount constructed according to the present invention and of a bone anchor for attachment to the anchor mount.  
     [0049]FIGS. 28B and 28C are end views of alternate embodiments of an anchor mount constructed according to the present invention.  
     [0050]FIG. 29A is an enlarged view of one embodiment of the head assembly of the anchor placement device of FIG. 27A, and of a recessed anchor mount in a recessed position within the head assembly.  
     [0051]FIG. 29B is an enlarged view of one embodiment of the head assembly of the anchor placement device of FIG. 27A, and of a recessed anchor mount in an advanced position protruding from the head assembly.  
     [0052]FIG. 29C is an enlarged view of a push wire in point contact with the anchor mount of FIG. 29A  
     [0053]FIG. 29D is an enlarged view of a push wire secured to the anchor mount of FIG. 29A.  
     [0054]FIG. 30A is a side view of an alternate embodiment of the anchor placement device depicted in FIG. 27A.  
     [0055]FIG. 30B is an enlarged view of one embodiment of the head assembly of the anchor placement device of FIG. 30A, and of a recessed anchor mount in a recessed position within the head assembly. 
    
    
     DETAILED DESCRIPTION  
     [0056] The manual bone anchor placement devices disclosed provide a mechanism to translate manual linear force (i.e., an operator&#39;s hand squeezing a lever) into rotary force on a bone anchor screw. As used herein “placing a bone anchor screw” (or grammatical equivalents thereof) refers to rotational action on, and/or screwing in, of a bone anchor screw into bone. Manual actuation of the disclosed devices occurs when the operator squeezes or pulls a lever with, for example, a single hand. Force on the lever is mechanically transmitted through a force translator to a rotary force mechanism. Each of the disclosed devices is distinguishable by the type of rotary force mechanism used.  
     [0057] In one aspect of the invention, a manual bone anchor placement device uses a rotary force mechanism that includes a resilient element wrapped around a rotator (“wrap-around manual bone anchor placement device”). In a second aspect of the invention, a manual bone anchor placement device (“rack and rotator manual bone anchor placement device”) uses a rotary force mechanism that includes a rack and rotator assembly. In a third aspect of the invention, a manual bone anchor placement device uses a rotary force mechanism that includes a cup and washer assembly (“cup and washer manual bone anchor placement device”). A self-tapping bone anchor screw with a pre-attached suture is also disclosed, which may also be used with any of the aforementioned manual bone anchor placement devices. In addition, a recessed bone anchor mount is disclosed, which may be used with any of the aforementioned manual bone anchor placement devices. All of the devices are useful in, for example, transvaginal bone anchor screw insertion procedures.  
     [0058] Wrap-Around Manual Bone Anchor Placement Device  
     [0059] In the embodiment of the invention shown in FIG. 1, the manual bone anchor placement device  1  is substantially pistol- or gun-shaped. In this embodiment, the manual bone placement device  1  includes a handle  2  and a shaft  3 . The handle  2  has a gripping portion  26  to facilitate gripping by the user and a lever  4  through which the user may manually transmit force to the bone anchor placement device  1 .  
     [0060] As shown in FIG. 3A, the shaft  3  has a first end  3   a,  proximal to the handle  2 , and a second end or head end  3   h,  distal to the handle  2 . A force translator  12  runs through the shaft  2  and transmits linear force exerted manually on the lever  4  to a head assembly  35  positioned at the second end  3   h  of the shaft  3  (shown enlarged in FIG. 4A). The head assembly  35  is capable of engaging with a bone anchor screw  5  and includes the mechanism that translates linear force from the force translator  12  to rotary force on the bone anchor screw  5 .  
     [0061] The shaft  3  is curved to facilitate correct placement of the bone anchor placement device  1  to the proper bone anchor screw insertion site. The shaft  3  is generally linear at its proximal or first end  3   a  and angles upward near its head end  3   h.  The upward angle can be from about 0 degrees to about 135 degrees. In one embodiment of the invention, the upward angle is between about 75 degrees and about 100 degrees. In another embodiment of the invention, shown in FIG. 2, the upward angle is approximately 90 degrees. In some embodiments of the invention, the shaft  3  can be rotated about 360 degrees relative to the handle  2  (see dashed arrow in FIG. 1A).  
     [0062] As shown in FIG. 3A, the handle  2  of the manual bone anchor placement device  1  of the present invention may further include an action mechanism through which force from the lever  4  is transmitted to the force translator  12 . The action mechanism includes the lever  4 , a pivot  9 , and the proximal end of the force translator  12 . The force translator  12  is connected to the lever  4  by a connector  11  that is positioned beneath the pivot  9 . The action mechanism further includes a torsional spring  10  that abuts the lever  4  in the handle  2 .  
     [0063] In an embodiment of the invention shown in FIG. 3B, the connector  11  has a “slot and pin arrangement.” In this embodiment, a slot us is included in the portion of the lever  4  proximal to the pivot  9  and defines openings in the sides, front, and back of the lever  4 . A connector member  11   m  is configured to fit in the slot  11   s  and includes a pinhole  11   h.  The connector member  11   m  is coupled to the force translator  12  at the end of the connector member  11   m  distal to the pinhole  11   h.  The connector member is positioned within the slot  11   s  and secured by a pin  11   p  that extends through both the slot  11   s  and the pinhole  11   h.    
     [0064] In the embodiment of the invention shown in FIG. 3A, the lever  4  extends at least partially from the handle  2  and linear force on the lever  4  is exerted by pulling on the lever  4 . Because the pivot  9  is located above the connector  11 , the translator  12  is subjected to tensile loading (e.g., a pulling force) during activation and compressive loading (e.g., a pushing force) during release. The torsional spring  10  abutting the lever  4  thus forces the lever  4  into its original position for the next stroke.  
     [0065] Force exerted on the lever  4  is translated as linear force through the force translator  12 . As shown in FIG. 3A, the force translator  12  is a substantially linear member that extends from the handle  2  through the shaft  3  of the manual bone anchor device  1 . The force translator  12  may be rigid or flexible, so long as it is tensile. In one embodiment of the invention, the force translator  12  is a wire. Additional types of force translators  12  include, but are not limited to, a cable, a rod, suture material, a string, and the like. Suitable force translator  12  materials include metal, plastic, polymers (e.g., nylon, in the case of suture materials), copolymers, and the like.  
     [0066] In a further embodiment of the invention, washers  21  are positioned on the inside of the shaft  3  to reduce the friction caused by the force translator  12  contacting the inside surfaces of the shaft  3  (see FIG. 4A). The washers  21  can be made of Teflon® material or any material with a low coefficient of friction.  
     [0067] The section of the shaft portion that seats the head assembly  35  may be simply a wider extension of the head end  3   h  of the shaft  3  shown in FIG. 3A. Alternatively, the head assembly  35  may be provided within a head module  28  seated on the distal-most tip  3   b  of the shaft (as in FIGS. 4A, 4C, and  4 D, for example) and may be either integral with the shaft  3  or separable from the shaft  3 . The head assembly  35  includes a rotator  14 , a securing element  166 , and a resilient element  13 , shown in more detail in FIGS.  4 A- 4 D. The resilient element  13  is coupled to both force translator  12  and the rotator  14 . In one embodiment of the invention, as shown in FIGS. 4C and 4D, the resilient element  13  is a constant force spring that is welded to the end of the force translator  12  that is proximal to the rotator  14 .  
     [0068] Force is transmitted through the resilient element  13  to the rotator  14 , which rotates in response to this force. The rotator  14  has at least one protruding portion  15   p,  shown in more detail in FIGS. 4C and 4D, and is capable of frictionally and mechanically engaging with the securing element  166  (shown in more detail in FIGS. 5A, 5C,  5 F, and  5 G). The securing element  166  further includes an engaging portion  16  and a mating portion  6 . The mating portion  6  of the securing element  166  extends at least partly from the head end  3   h  of the shaft  3 , or the head module  28 , and mates with a bone anchor screw  5 .  
     [0069] In the embodiment of the invention shown in FIGS.  4 A- 4 C, the rotator  14  has at least one floating pawl and the engaging portion  16  of securing element  166  has teeth  17  that are capable of meshing with the protruding portion  15   p  of the floating pawl and rotating in response to the rotation of the pawl. The protruding portion  15   p  extends from a flat spring member  15   s  as shown in FIGS. 4C and 4D. The flat spring member  15   s  may be angled or bent, as shown in more detail in FIGS.  8 A- 8 C, to control the position of the protruding portion  15   p  of the pawl.  
     [0070] It will be readily apparent to one of ordinary skill in the art that any number and type of protruding portions  15   p  may be provided so long as they are able to frictionally and mechanically engage with the engaging portion  16  of the securing element  166  to cause rotation of the securing element  166 . In the embodiment of the invention shown in FIG. 4B, the rotator  14  includes three floating pawls that are spaced equidistant from each other about a central axis of rotation. In another embodiment of the invention, shown in FIG. 4C, the rotator  14  includes two floating pawls, and the teeth  17  of the engaging portion  16  are designed to allow one-directional engagement with the pawls. Slip-free rotation of a bone anchor screw  5  is provided by this design.  
     [0071] In the embodiment of the invention shown in FIGS. 4C and 4D, the rotator  14  is contained within a rotatable housing  18  positioned within the head module  28  and is fitted into at least one groove  22  within the inner wall of the rotatable housing  18 . FIGS.  6 A- 6 C show enlarged views of the rotatable housing  18 . In the embodiment of the invention shown in FIGS. 6A and 6C, the rotatable housing  18  has two grooves  22  to accommodate a rotator  14  that includes two floating pawls.  
     [0072] In the embodiment of the invention shown in FIGS.  4 A- 4 D, the resilient element  13  is at least partially wound around the rotatable housing  18 , and the rotatable housing  18  and the rotator  14  move as one. The resilient element  13  is secured to the rotatable housing  18  by the insertion of an inwardly projecting tail  13   t  of the resilient element  13  into a notch  25  in the rotatable housing  18 . An enlarged view of the resilient element  13  and inwardly projecting tail  13   t  is shown in FIG. 9.  
     [0073] As shown schematically in FIG. 10, force transmitted through the resilient element  13  causes the inner diameter ID of the resilient element  13 , which is wrapped around the rotatable housing  18 , to decrease and the resilient element  13  to grip the rotatable housing  18 , resulting in its rotation. Upon elimination of force on the resilient element  13 , the inner diameter ID of the portion of the resilient element  13  wrapped around the rotatable housing  18  gets larger, resulting in free rotation in the opposite direction. The gripping action in one direction and the slipping action in the opposite direction provide the action needed to drive a bone anchor screw  5  into the bone when a linear pull force is exerted on the lever  4 .  
     [0074] In the embodiment of the invention shown in FIGS. 4C and 4D, the securing element  166  is positioned at least partially within the rotatable housing  18 , and the engaging portion  16  of the securing element  166  rotates in response to the rotation of the rotatable housing  18  and rotator  14 .  
     [0075] As shown in the enlarged view of the securing element  166  provided in FIGS. 5A and 5C, the securing element  166  further includes a generally cylindrical front piece  19  that extends from the engaging portion  16  of the securing element and fits into a complementary recessed portion  30  in the inner wall of the head end  3   h  of the shaft  3  or the head module  28  (shown in FIGS. 12A, 12B, and  12 C). The front piece  19  acts to position the rotatable housing  18  within the head end  3   h  of the shaft  3  or within the head module  28  (as shown in FIGS. 12A, 12B, and  12 C), allowing it to rotate freely about the axis defined by the front piece  19 .  
     [0076] The mating portion  6  of the securing element  166  extends at least partially outside the head end  3   h  of the shaft  3 . The bone anchor screw  5  may be seated on the mating portion  6  of the securing element  166  in a variety of ways and the mating portion  6  of the securing element  166  may be fabricated to complement a variety of different types of bone anchor screws  5 . In one embodiment of the invention, shown in FIG. 5E, when the bone anchor screw  5  being used provides a shaft  5   a  with a hex-shape, the mating portion  6  of the securing element  166  is designed to provide a recess  6   a  that has a hex-shaped cross-section (see FIGS. 5A, 5B, and  5 D). It will be readily apparent to one of ordinary skill in the art that the recess  6   a  of the mating portion  6  of the securing element  166  may be any type of shape (e.g., a T-shape or an X-shape) that allows for frictional and mechanical engagement with a bone anchor screw  5  having a shaft  5   a  with the corresponding shape. In a further embodiment of the invention, shown in FIGS. 5F and 5G, the mating portion  6  of the securing element  166  has a shaft  6   b  while the bone anchor screw  5  (shown in FIG. 5H) provides a recess  5   b  complementary to the shape of the shaft  6   b    
     [0077] Any type of bone anchor screw  5  may be used adaptable to the mating portion  6  of a selected securing element  166 . In one embodiment, shown in FIG. 1A, the bone anchor screw  5  has a pre-attached suture  7  and the walls of the shaft  3  defining the head end  3   h  of the shaft have aligned openings  20   a  and  20   b  through which the suture  7  is threaded. (Aligned openings may also be provided in the head module  28  in embodiments of the invention where the bone anchor placement device comprises a head module  28 .) Attachment of the suture  7  along the length of the shaft  3  will keep the suture  7  from becoming entangled during the bone anchor screw insertion procedure.  
     [0078] In the embodiment of the invention shown in FIGS.  1 A- 1 C, the length of the suture  7  extending out of the head end  3   h  of the shaft  3  may be secured by one or more suture rings  8  mounted on the shaft  3 . The suture rings  8  may be an integral part of the shaft  3  or may be clipped on as shown in FIG. 1B. After the bone anchor screw  5  is seated, the bone anchor screw  5  disengages from the mating portion  6  of the securing element  166 . The suture  7  then slips through aligned openings  20   a  and  20   b  at the head end  3   h  of the shaft  3  and through the suture rings  8 , disengaging from the bone anchor placement device  1 .  
     [0079] In another embodiment of the invention, shown in FIG. 2, a groove  23  is cut into the outer surface of the handle  2 , extending in a line parallel to the longitudinal axis of the shaft  3 , which is proximal to the gripping portion  26  of the handle  2 . In this embodiment of the invention, the suture  7  is enclosed within a flexible, molded sleeve  24 , composed of Teflon® material, for example, which is press-fitted into the groove  23  of the handle  2 . In a further embodiment of the invention, a retaining clip  27  may be provided at the end of the sleeve  24  proximal to the gripping portion  26  of the handle  2  to prevent the suture  7  from slipping out before the bone anchor screw  5  is screwed into the bone. The user of the manual bone anchor placement device  1  may then cut the retaining clip  27 , which allows the suture  7  to slide out of sleeve  24  after the bone anchor  5  is screwed into the bone.  
     [0080] In further embodiments of the invention, the manual bone anchor placement device  1  may be fabricated from modules including a handle module and a shaft module, allowing the user to mix and match different handles  2  with different shafts  3  (including different head assemblies  35 ). In the embodiment of the invention shown in FIG. 11, the handle module comprises the two halves  2   a  and  2   b  of the handle  2  (including the two halves  26   a  and  26   b  of the gripping portion  26 ) that are separable from each other. In this embodiment, an old shaft  3   o  may be removed from the handle  2  upon disconnecting the force translator  12  from the connector  11 . A new shaft  3   nu  may then be positioned within the handle  2 . After connecting the force translator  12  of the new shaft  3   nu  to the connector  11 , the two halves  2   a  and  2   b  of the handle  2  are snapped back together and the wrap-around manual bone anchor placement device  1  is ready for use.  
     [0081] In the embodiment shown in FIG. 11, interchanging the old shaft  3   o  from the original bone anchor placement device  1  with a new shaft  3   nu  provides the user with the opportunity to replace a shaft  3  with an approximately 30 degree upward angle with one with an approximately 90 degree upward angle and a different type of head end  3   h.  The modular nature of the wrap-around bone anchor placement device  1  thus allows users to select the type of shaft  3  or head end  3   h/ head module  28 /head assembly  35  that best suits their needs and facilitates repairs of the device  1 .  
     [0082] As shown in FIGS.  12 A- 12 I, the front half  28   f  and back half  28   b  of the head module  28  may also be separated by unscrewing screws at coupling regions  33 . This allows the user to vary the exact configuration of the head module  28  and head assembly  35  being used with a particular shaft  3 .  
     [0083] In the embodiment shown in FIGS. 12E, 12G, and  12 H, the front half of the head module  28   f  may also be provided with a protruding threaded element  31 . As shown in FIG. 13A, a protective cover  32  may be seated on this threaded element  31 , providing a covering for the bone anchor screw  5  extending outside of the head module through opening  36  and protecting the tip of the bone anchor screw  5  from damage before it contacts a bone insertion site. In a further embodiment of the invention, shown in FIGS. 13B and 13C, the protective cover for protecting a bone anchor screw has a base  32   b  for engaging the shaft  3  of the manual bone anchor placement device  1 , and a sheath  32   s  coupled to the base  32   b  for surrounding and protecting the bone anchor screw  5 . The sheath  32   s  is collapsible and collapses as the bone anchor screw  5  is driven into bone, thereby uncovering the bone anchor screw  5 . Sheath  32   s  materials include flexible plastic, rubber, thin pleated metal, and the like.  
     [0084] In still a further embodiment of the invention, shown in FIG. 14, the mating portion  6  of the securing element  166  may be uncoupled from the engaging portion  16  of the securing element  166  without opening the head end  3   h  or head module  28 . In this embodiment of the invention, the mating portion  6  of the securing element  166  is threaded onto a threaded element  34  that protrudes from the engaging portion  16  of the securing element  166  and may be unscrewed from the engaging portion  16  of the securing element  166 . This embodiment of the invention allows different types of mating portions  6  to be coupled to the engaging portion  16  of the securing element  166  and thus allows the user to select a mating portion  6  of a securing element  166  that is complementary to any desired type of bone anchor screw  5 .  
     [0085] Rack and Rotator Manual Bone Anchor Placement Device  
     [0086] As shown in FIG. 15, the rack and rotator manual bone anchor placement device  36 , like the wrap-around device  1 , is substantially pistol- or gun-shaped and includes a handle  2  and a shaft  3 . The handle  2  includes a gripping portion  26  and a lever  4  through which a user may manually transmit linear force to the rotary force mechanism of the device  36 . Like the wrap-around device  1 , the shaft  3  of the rack and rotator manual bone anchor placement device  36  has a first end  3   a  proximal to the handle  2 , and a second end, or head end  3   h,  distal to the handle  2 .  
     [0087] As in the wrap-around device  1 , the shaft  3  of the rack and rotator manual bone anchor placement device  36  is curved to facilitate correct placement of the bone anchor placement device  36  to the proper bone anchor screw insertion site, angling upward near its head end  3   h. The upward angle can be from about 0 degrees to about 90 degrees. In one embodiment of the invention, the upward angle is between about 35 degrees and about 60 degrees. In the embodiment of the invention shown in FIG. 15, the upward angle is approximately 45 degrees. The upward angle of the shaft  3  may be optimized to facilitate insertion of a bone anchor screw  5 . The shaft  3  can also be rotated about 360 degrees relative to the handle portion  2  (see dashed arrow in FIG. 15).  
     [0088] As in the wrap-around manual bone anchor placement device  1 , the rack and rotator manual bone anchor placement device  36  has an action mechanism through which force on the lever  4  is transmitted to the force translator  12 . The action mechanism includes lever  4 , pivot  9 , and the proximal end of the force translator  12 . A torsional spring  10  abuts the lever  4  in the handle  2 . The force translator  12  is connected to the lever  4  by a connector  11 , but the position of the connector  11  relative to the pivot  9  may be varied. As in the wrap-around manual bone anchor device  1 , the force translator  12  may be rigid (e.g., a rod) or flexible (e.g., a spring, wire, string, suture material, or the like).  
     [0089] Unlike the wrap-around bone anchor placement device  1 , in which a pushing force is transmitted to the force translator  12  by squeezing the lever  4  towards the gripping portion  26  of the handle  2 , the rack and rotator bone anchor placement device  36  may be configured so that either a push force or a pull force may be transmitted through the force translator  12  by squeezing the lever  4 .  
     [0090] In the “pull” embodiment, shown in FIG. 18A, pivot  9  is positioned above connector  11 . In this embodiment, mechanical actuation of the lever  4  causes the force translator  12  to be subjected to tensile loading, i.e., a pulling force, when the user squeezes the lever  4  toward the gripping portion  26  of the handle  2 , and compressive loading when the user releases the lever  4 .  
     [0091] In the “push” embodiment shown in FIG. 18B, pivot  9  is positioned below connector  11  which connects force translator  12  to the lever  4 . Squeezing the lever  4  in this embodiment causes the force translator  12  to be subjected to compressive loading, or a pushing force.  
     [0092] Force translator  12  runs through the shaft  3  and transmits linear force exerted manually on the lever  4  to a head assembly  37  positioned at the head end  3   h  of the shaft  3 . Washers  21  positioned on the inside of the shaft  3  reduce the friction caused by the force translator  12  contacting the inside surfaces of the shaft  3  (see FIG. 15).  
     [0093] Head assembly  37  includes a rack  38  and a rotator  14 . The rotator  14  includes at least one protruding portion  15   p,  and a coupler  43 . Head assembly  37  performs a similar function in the rack and rotator bone anchor placement device  36  as head assembly  35  does in the wrap-around device  1 , translating linear force from the force translator  12  to rotary force on a bone anchor screw  5 , but does so through a different mechanism.  
     [0094] As shown in FIG. 16, the distal end of the force translator  12  is coupled to rack  38 , which is positioned proximal to rotator  14 . The rack  38  is only able to move in the y direction while the rotator  14  is only able to move rotationally about the x-axis. When the rack  38  moves into an engaging position relative to the rotator  14 , the teeth of rack  38  mesh with the protruding portion  15   p  of rotator  14 , causing the rotator  14  to rotate. Thus, linear force transmitted through the force translator  12  translates into movement of the rack  38  along the y-axis, which in turn translates into rotation of the rotator  14  about the x-axis. The rotator  14  is coupled to coupler  43 , which is capable of mating with or engaging a bone anchor screw  5 . Rotation of the rotator  14  is translated into a torque applied on the coupler  43 , which in turn drives or screws a bone anchor screw  5  into bone. Rotators  14  that may be used with racks  38  of the present invention include ratchet wheels, pawls, pinions, gears, and the like.  
     [0095] In the embodiment of the invention shown in FIG. 16, the rotator  14  is a ratchet wheel. In this embodiment of the invention, the interior of the head end  3   h  of the shaft  3  comprises a grooved element  40  that includes an actuating groove  41  and a return groove  42 . A head assembly spring  39  is also positioned within the head end  3   h  and is coupled by a first end  39   f  to the inner wall of the head end  3   h  of the shaft  3  distal to rack  38  and at a second end  39   s  to force translator  12 . Squeezing lever  4  exerts a linear pull force on the translator  12 , which mechanically pulls the rack  38  along the actuating groove  41  towards the rotator/ratchet wheel  14 . When the rack  38  reaches an engaging position it engages the protruding portions  15   p  of the rotator/ratchet wheel  14  and rotates the rotator/ratchet wheel  14 , which in turn rotates coupler  43 . Coupler  43  engages or mates with a bone anchor screw  5 , and rotation of the coupler  43  applies a torque on the bone anchor screw  5 , thereby screwing it into bone.  
     [0096] Release of lever  4  by the operator transmits a compressive force through the force translator  12  (in this embodiment, a flexible wire) to the head assembly spring  39 . A push force exerted by head assembly spring  39  in response to this compressive force forces the rack back into return groove  42  during the return stroke and disengages the rack  38  from the rotator  14 .  
     [0097] The rack and rotator rotary force mechanism shown in FIG. 16 may also be adapted for a push embodiment. In a push embodiment, compressive loading on the force translator  12  forces the rack  38  forward to engage the rotator/ratchet wheel  14 , which rotates in response to this engagement. The rotation of the rotator/ratchet wheel  14  rotates coupler  43 , which in turn applies torque on a bone anchor screw  5 . By varying the position of the connector  11  relative to the pivot  9  in the action mechanism as shown in FIGS. 18A and 18B, the device  36  may be configured to be used in either a pull or push embodiment.  
     [0098] In the embodiment of the invention shown in FIG. 17, the rotator  14  is a pinion. Rotary motion from the rotator/pinion  14  is transmitted to a bone anchor screw  5  through coupler  43 , which extends at least partially through the head end  3   h  of the shaft  3  through opening  200   a.  A push force or a pull force may be transmitted through the force translator  12 , as discussed above, by varying the position of the connector  11  relative to the pivot  9  in the action mechanism of the device  36 . A rotator spring  44  provides an opposing force to return the rotator/pinion  14  to its original position. In the embodiment of the invention shown in FIG. 17, the bone anchor screw  5  is pre-attached to a suture  7 , and both the coupler  43  and the rotator/pinion  14  have openings through which the suture  7  is threaded. The suture  7  dangles from the head end  3   h  of shaft  3  through opening  200   b.    
     [0099]FIG. 19 shows an embodiment of the invention in which the rotator  14  is a pinion, and a compressive force, or push force, is transmitted on a force translator  12 . An opposing compressive force is provided by rack spring  45 , shown in cross-section in the Figure, that encircles the end of the force translator  12  proximal to rack  38  and forces the rack  38  back to its original position during a release stroke.  
     [0100]FIG. 20 shows a further embodiment of the invention in which the force translator  12  includes a first wedge member  46  at the end of the force translator  12  distal to the rack  38 . In this embodiment, the force translator  12  is not directly coupled to the lever  4 , but terminates substantially at the neck  47  of the head end  3   h  of the shaft  3 . The translator  12  receives force from a tubular member  48  that terminates in a second wedge member  49  and is connected to the lever  4  at connector  11 . Actuation of the lever  4  pushes the second wedge member  49  against the first wedge member  46  and transmits a compressive force, i.e., a push force, to the force translator  12 . During the release stroke, rotator spring  44  forces the rotator/pinion  14  back to its original position while rack spring  45  forces the rack  38  into its initial position.  
     [0101]FIG. 21 shows a further embodiment of the invention in which hydraulic or pneumatic pressure is used to exert a compressive, or push force, on a force translator  12   p.  In this embodiment of the invention, the force translator  12   p  is a plunger positioned in close proximity to the rack  38 . An o-ring  50  maintains a seal separating air or fluid in the shaft  3  from the rack  38  and rotator/pinion  14  assembly. Hydraulic or pneumatic forces transmitted through the shaft  3  upon actuation of the lever  4  drive the plunger  12   p  forward, transmitting linear force from the plunger  12   p  to the rack  38 , which is in turn pushed forward to engage the rotator/pinion  14 . The rotator/pinion  14  rotates and transmits rotary force to coupler  43 , which applies a torque to a bone anchor screw  5 . Opposing compression forces from rotator spring  44  forces the rotator/pinion  14  back to its original position while rack spring  45  forces the rack  38  to return to its initial position.  
     [0102] As will be readily apparent to those of ordinary skill in the art, many of the features of the wrap-around manual bone anchor placement device  1  may be adapted for use with the rack and rotator manual bone anchor placement device  36 . For example, a suture  7  pre-attached to a bone anchor screw  5  may be clipped to the shaft  3  by suture rings  8  to keep the suture  7  from becoming entangled during the bone anchor screw  5  insertion procedure. Alternatively, the suture  7  may be enclosed within a flexible, molded sleeve  24  press-fitted into a groove  23  cut into the handle  2 . A retaining clip  27  provided at the end of the sleeve  24  proximal to the gripping portion  26  of the handle  2  may be provided to prevent the suture  7  from slipping out of the sleeve  24  before the bone anchor screw  5  is screwed into bone.  
     [0103] The coupler  43  may also be configured to be adapted to a wide variety of bone anchor screws  5 . Like the securing element  166  of the wrap-around bone anchor placement device  1 , the coupler  43  of the rack and rotator manual bone anchor placement device  36  includes a mating portion  43   m  that extends at least partially outside head end  3   h  of the shaft  3  and which can be fabricated to complement different types of bone anchor screws  5 . In the embodiment of the invention shown in FIG. 19, the coupler  43  provides a mating portion  43   m  that is a hex-shaped recess that seats a bone anchor screw  5  with a hex-shaped shaft  5   a,  (e.g., as shown in FIG. 5E). The mating portion  43   m  of the coupler  43  may be configured in any type of shape (e.g., shaft or recess) that allows for frictional and mechanical engagement with a bone anchor screw  5  having the corresponding shape (e.g., recess or shaft).  
     [0104] As with the wrap-around manual bone anchor placement device  1 , a protective cover  32  may be provided to protect the tip of the bone anchor screw  5  from damage before it contacts a bone insertion site, and may be collapsible to expose the bone anchor screw  5  only when it contacts the bone.  
     [0105] As with the wrap-around manual bone anchor placement device  1 , the rack and rotator bone anchor placement device  36  may be fabricated in a modular configuration to provide for the ready interchange of different head modules and shaft modules. For example, a shaft  3  that has a rack and rotator head assembly  37  may be interchanged with a shaft  3  having the same type of head assembly  37 , but with a different angle of curvature. Alternatively, a shaft  3  with a rack and rotator head assembly  37  may be interchanged with a shaft  3  having a wrap-around head assembly  35 . Similarly, different couplers  43  may be interchanged to facilitate the use of different bone anchor screws  5 .  
     [0106] Cup and Washer Manual Bone Anchor Placement Device  
     [0107] As with the previously disclosed manual bone anchor placement devices  1  and  36 , the cup and washer manual bone anchor placement device  52 , is configured to be substantially pistol- or gun-shaped, having a handle  2  with a gripping portion  26  and a lever  4 . In the cup and washer manual bone anchor placement device  52 , however, the “barrel of the gun” is formed by a driver rod  53  that extends through the handle  2  and is substantially perpendicular along its length to the longitudinal axis of the gripping portion  26  of the handle  2 .  
     [0108]FIGS. 22A and 22B show a cross-section of the cup and washer manual bone anchor placement device  52 . The driver rod  53  includes a smooth portion  54  and a lead screw portion  55  with integral single or multistart threads  55   t.  The lead screw portion  55  may be integral with the smooth portion  54 . Alternatively, the lead screw portion  55  may be screwed onto threads or grooves at one of the ends of the smooth portion  52 . The lead screw portion  55  may extend from one end of the handle  2  to the other end of the handle  2  or the lead screw portion  55  may comprise a substantial portion of the driver rod  53 . As used herein, “a substantial portion” refers to greater than 50% of the length of the driver rod  53 . In a different embodiment of the invention, the driver rod  53  may be flat stock twisted into a spiral with a long pitch.  
     [0109] The lead screw portion  55  of the driver rod  53  further includes an engaging element  55   e  at the end of the lead screw portion  55  distal to smooth portion  52  of the driver rod  53 . The engaging element  55   e  engages with a coupling member  59 . The coupling member  59  has a mating portion  59   m  for mating with a bone anchor screw  5  and an engaging portion  59   e  for engaging with the engaging element  55   e  of the lead screw portion  55 .  
     [0110] The position of the coupling member  59  relative to the lead screw portion  55  of the driver rod  53  may be controlled by means of a coupling member stop  59   s.  A chuck  57  provided at the barrel end  56  of the handle  2  further secures coupling member  59  to the lead screw portion  55  of the driver rod  53 . Since the chuck  57  contacts both the lead screw portion  55  of the driver rod  53  and the coupling member  59 , any force transmitted through the driver rod  53  is also transmitted through the coupling member  59  to the bone anchor screw  5 . In a further embodiment of the invention, a rotatable twist lock  58  is provided, thereby supplying an additional means of securing the chuck  57  to coupling member  59 .  
     [0111] The rotary force mechanism in the cup and washer manual bone anchor placement device  52  includes cup and washer assembly  60 , which includes a cup  61 , a washer  62 , and at least one engaging pin  65 . The cup  61  is capable of axial movement along the lead screw portion  55  of the driver rod  53 , while the washer  62  is capable of both axial motion and rotational motion along the lead screw portion  55 .  
     [0112] Movement of the cup  61  is controlled by actuation of an action mechanism that includes a lever  4  and a force-translating member  64 . The force-translating member  64  has a first end  64   f  and a second end  64   s.  The first end  64   f  of the force-translating member  64  is coupled to the lever  4  at pivot point  9  while the second end  64   s  is coupled to the side of the cup  61  by means of flanges  61   f  on the cup. The flanges  61   f  form a yoke that links the cup  61  to the force-translating member  64 . The cup  61  is thus free to ride on the lead screw  55  in response to movement of force translating member  64 .  
     [0113] The cup and washer manual bone anchor placement device  52  operates on the principle of a child&#39;s top. Applying a linear force on the lever  4  by squeezing it towards the gripping portion  26  of the handle  2  actuates the action mechanism. Linear force is transmitted from the lever  4  to the force-translating member  64  and is transmitted to cup  61 . In the embodiment of the invention shown in FIG. 23, the cup  61  has two engaging pins  65  that fit into complementary holes  66  in the washer  62 . The cup  61  is capable of engaging and disengaging the washer  62  depending upon its direction of travel, while the washer  62  includes protrusions  67  that allow it to move along and follow the thread pitch of the threads  55   t  of the lead screw portion  55  of the driver rod  53 . In the embodiment of the invention shown in FIG. 23A, the lead screw portion  55  includes grooves  66   g  complementary to protrusions  67  in the washer  62 . In the embodiment of the invention shown in FIGS. 24A and 24B, the engaging pins  65  of the washer  62  further include tangs  65   t,  and the cup  61  includes ribs  71  that constrain the motion of the washer  62  further when the tangs  65   t  of the washer  62  contact the walls of the ribs  71 .  
     [0114] Upon squeezing the lever  4 , the translating member  64  is driven forward, moving the cup  61  forward at the same time (see dashed arrows in FIGS. 22A and B). When the motion of the cup  61  is initiated, the washer  62  is forced by the lead screw portion threads  55   t  into contact with the cup  61 . The engagement pins  65  of the cup  61  then engage with the washer  62 . Once engaged, the washer  62  is no longer free to rotate or spin on the lead screw portion threads  55   t.  As the translational member  64 , cup  61 , and washer  62 , advance in a linear, forward direction, linear force from the force translating member  64  on the cup  61  is translated into rotary force upon the lead screw portion  55  of the driver rod  53 , causing the driver rod  53  and the coupling member  59 , which is coupled to it, to twist as the washer  62  follows the threads  55   t  of the lead screw portion  55 . This twisting motion in turn applies a torque to a bone anchor screw  5  engaged by the coupling member  59 , thereby screwing the bone anchor screw  5  into bone.  
     [0115] On the lever return stroke, there is minimal linear force imposed upon the coupling member  59 . The cup  61  provides the washer  62  with clearance to disengage from the engaging pins  65  of the cup  61  and to rotate freely as the washer  62  follows the threads  55   t  on the lead screw portion  55  of the driver rod  53 . In a further embodiment of the invention, shown in FIG. 22B, a return coil spring  68  may provided at the barrel end  56  of the handle  2  to further apply a return compressive force on the cup  61  and translating member  64  when the lever  4  is released.  
     [0116] By incorporating a 60-degree pitch angle and 3-start thread, the complete seating of a bone anchor screw  5  can take place in approximately 10 strokes of the lever  4 . Optimizing thread  55   t  design, lever  4  stroke and/or cup  61 /washer  62  clearance can reduce the number of strokes.  
     [0117] It should be readily apparent to one of ordinary skill in the art that the engaging pins  65  may be provided on the washer  62  side rather than the cup  61  side and that the holes  66  may be provided in the cup  61 . The number of engagement pins  65  may also be varied. The engaging pins  65  may be an integral part of the washer  62  or cup  61 , or may be removable from the washer  62  or cup  61 . In addition, the number of starts in the multistart thread  55   t  of the lead screw portion  55  of the driver rod  53  may be varied from one through what ever number is dimensionally practical for the driver rod  53  diameter.  
     [0118] In a further embodiment of the invention as shown in FIGS. 22A, 22B,  24 A, and  25 B, a cover plate  63  is provided at the rim  69  of the cup  61  to contain the washer  62  within the cup  61  and to permit only minimal travel space for the washer  62  to move in when it is drawn free from the engaging pins  65  of the cup  61 .  
     [0119] As with the previously disclosed manual bone anchor placement devices  1  and  36 , the cup and washer manual bone anchor placement device  52  may be used with a bone anchor screw  5  with a pre-attached suture  7  that may be enclosed within a sleeve  24  press-fitted into a groove  23  cut into handle portion  2 . The mating portion  59   m  of the coupling member may be configured to mate with a variety of bone anchor screws  5 , and may include a shaft configured in a shape complementary to a recess in a bone anchor screw  5  or may include a recess complementary to a shaft in a bone anchor screw  5 . As in the previously disclosed devices  1  and  36 , the cup and washer manual bone anchor placement device  52  may include a modular design allowing for the interchange of different types of coupling members  59 . The handle portion  2  may also be configured to include two separable halves that are able to snap-fit together, allowing removal of one driver rod and/or cup and washer assembly and replacement with another.  
     [0120] Self-Tapping Bone Anchor Screw  
     [0121]FIG. 26 shows a bone anchor screw  5  according to one embodiment of the invention. As shown in the FIG. 26, the threads of the bone anchor screw  5  are of buttress form. The forward face  72  of the screw thread is perpendicular to the longitudinal axis  73  of the bone anchor screw  5  while the back face  74  of the screw thread is at an acute angle relative to the longitudinal axis  73  of the bone anchor screw  5 . The threads extend to the tip of the screw shank  75 , reducing the amount of torque required to seat the bone anchor screw  5 . In one embodiment of the invention, the back face  74  of the screw thread is at about a 30-degree angle relative to forward face  72  of the screw thread.  
     [0122] The base  76  of the bone anchor screw  5  shown in FIG. 26A has an eyelet  77  that is circular and has micropolished edges. In another embodiment of the invention, the eyelet  77  at base  76  may be teardrop shaped, or ellipsoidal. Other configurations may be used so long as the edges are rounded so as not to damage the suture  7 . Micropolishing the eyelet  77  rounds the edges and reduces load to the suture  7  that may be caused by twisting (torsional load) during insertion, the user tugging on the suture  7  to test seating of the screw, and bodily movement while the anchor screw and suture are in place.  
     [0123] According to a further embodiment of the invention, kits including the disclosed self-tapping bone anchor screw may be provided for the convenience of the user. In one embodiment of the invention, a kit is provided, including at least one of: 1) a flexible, molded sleeve  24  for enclosing a suture  7 , 2) a retaining clip  27  for preventing the suture  7  from slipping out of the sleeve  24 , 3) a buttress-shaped bone anchor screw  5  with a micropolished eyelet  77  for receiving the suture  7 , and 4) suture material, which may or may not, be pre-attached to the bone anchor screw  5 . The kit may include any one of these elements or combinations thereof.  
     [0124] Recessed Bone Anchor Mount  
     [0125] The recessed bone anchor mount is designed to be used in conjunction with the various bone anchor placement devices described hereinabove; however, the recessed mount is not limited to use with only those types of bone anchor placement devices.  
     [0126]FIG. 27A is a perspective view of one embodiment of a bone anchor placement device  210  constructed according to the present invention. The anchor placement device  210  includes a handle  212 , and a shaft  214  extending in a distal direction from the handle  212 . A head assembly  216  is disposed at a distal end  218  of the shaft  214 , and defines a core  220  that may be further defined by driver guide  300 . A recessed anchor mount  222  is fixedly engaged within the core  220 . In one embodiment, the handle  212  includes an actuator  224  for actuating a mechanism  226  for advancing or retracting the anchor mount  222 .  
     [0127] The handle  212  serves as a gripping area for a surgeon, and is preferably of a size that makes it easily grippable by a user. A handle that is at least about 4 inches (100 mm) in length has been found to work well. The handle  212  may be made of any relatively firm material, including plastic or metal. For example, the handle  212  may be made of plastic, aluminum, stainless steel, or titanium. Those skilled in the art will appreciate that a wide range of other materials may also be employed. The handle  212  may be configured in any of a variety of shapes compatible with vaginal insertion of the anchor placement device  210 . In the embodiment shown in FIG. 27A, the handle  212  tapers towards the proximal end to facilitate gripping by the user. Preferably, the handle  212  is provided with knurling or other surface texturing to produce a high friction, non-slip gripping surface.  
     [0128] The shaft  214  extends in a distal direction from the handle  212 , and is adapted for releasably engaging a bone anchor  230 . The shaft  214  has a distal end  218 , and a proximal end  228 . The shaft  214  may be curved or angled at one or more portions to facilitate correct placement of the bone anchor placement device  210  to a proper bone anchor insertion site. The shaft  214  may be made of any of a variety of materials; including steel, stainless steel, aluminum, titanium, and plastic, but is preferably made of stainless steel. The shaft  214  may have a variety of cross-sectional shapes including round, elliptical, rectangular, hexagonal, or triangular, but preferably the shaft  214  has a round cross-section.  
     [0129] The length of the shaft  214  is consistent with transvaginal delivery of a releasable bone anchor  230  and may be of an appropriate length to permit access of the bone anchor  230  to the desired location. The cross-sectional dimension of the shaft  14  is a function of the force-translating mechanism (variations of which are described hereinabove) and the actuator mechanism  226  and may range from about 0.2 to about 1.0 inch in diameter.  
     [0130]FIG. 28A is an enlarged view of one embodiment of a recessed anchor mount  222  constructed according to the present invention and of a bone anchor  230  for attachment to the anchor mount  222 . The mount  222  has a distal end  223  and a proximal end  229 . In one embodiment, the mount  222  has a hexagonal interior lumen  232 , and a matching or complimentary outer surface  234 . The mount  222  may have other configurations for its interior lumen  232  and outer surface  234 , such as a rectangular, pentagonal, octagonal, or round. FIG. 28B depicts an end view of an alternative anchor mount  222  with a primarily round outer surface  234  and a groove  235  for interlocking with a pin or protuberance (not shown) within the driver guide  300 . FIG. 28C depicts an end view of an alternative anchor mount  222  with a primarily round outer surface  234  and a flat surface  237  for interlocking with a mating flat surface (not shown) within the driver guide  300 .  
     [0131] A variety of bone anchors  230  can be used. In one embodiment, the bone anchor  230  includes a spear member  236  that is able to pierce and securely engage a bone or bone tissue. The spear member  36  has a generally cone shaped head portion  238  which is used to pierce the bone and a shaft portion  240  with an eyelet  242  therethrough for receiving and holding one or more suture strands  241 .  
     [0132] The outer surface of the shaft portion  240  of the anchor  230  is shaped to fit within the anchor mount  222 , and is adapted to rotate with the anchor mount  222 . In preferred embodiments, the shaft portion  240  has the eyelet  242  formed radially therethrough proximate one of its ends. The eyelet  242  may be of any shape and is of a sufficient size to permit a suture strand or strands  241  to pass therethrough. The circumference of each outer end of the eyelet  242  is preferably chamfered or grounded to provide a beveled surface. A beveled surface provides a generally smooth surface for contacting a suture strand  41  that has been passed through the eyelet  242 . The eyelet  242  is preferably located on the shaft portion  240  of the anchor  230  such that the transverse axis of the eyelet  242  intersects the longitudinal axis of the spear member  236 .  
     [0133] The generally cone-shaped head portion  238  of the spear member  236  is located at an end of the shaft portion  240  opposite the end having the eyelet  242 . The apex of the cone-shaped head portion may terminate in a sharp tip or point  243  that is suitable for being driven into bone. The diameter of the cone-shaped head portion  238  increases, when viewed along its longitudinal direction rearwardly from the point  243 , towards the shaft portion  240 .  
     [0134] Any known materials suitable for orthopedic anchor devices may be employed to construct the bone anchor  230  of the present invention. Preferably, the bone anchor  230  is formed from a plastic polymer or metallic material possessing sufficient strength to penetrate and anchor to bone. Such materials include titanium, 316 LVM stainless steel, CoCrMo alloy, Nitinol alloy, or polymers, for example, polyglycolic acid (PGA) with or without absorbability properties. Preferably, the bone anchor is made of titanium.  
     [0135]FIG. 29A is an enlarged view of one embodiment of the head assembly  216  of the anchor placement device  210  of FIG. 27A, and a recessed anchor mount  222  housed within the head assembly  216  in a retracted position.  
     [0136] The head assembly  216  is capable of releasably engaging a bone anchor mount  222  and is connected to a mechanism  226  that translates axial motion to the mount  222  to advance or retract the anchor  230 . The head assembly  216  defines a hollow core  220  that may be further defined by driver guide  300 . The interior dimensions of the core  220 , or driver guide  300 , permit a recessed anchor mount  222  to be moveably fitted therein. In preferred embodiments, the interior dimensions of the core  220 , or driver guide  300 , are only slightly larger than the exterior dimensions of the anchor mount  222 . The length of the anchor mount  222  is about 0.12 to about 0.25 inches, preferably about 0.15 to about 0.20 inches, and more preferably about 0.185 inches. The length of the driver guide  300  is essentially the length of the anchor mount  222  and the anchor  230 .  
     [0137] In preferred embodiments, the core  220  has a shape complementary to the proximal end  229  of the anchor mount  222 , so as to permit the mount  222  to engage the driver guide  300 . For example, the driver guide  300  and the proximal end  229  of the anchor mount  222  may be square, rectangular, pentagonal, triangular or hexagonal in cross-section. In some embodiments, the driver guide  300  and the proximal end  229  of the anchor mount  222  have hexagonal cross-sections; however, those skilled in the art will appreciate that numerous shapes may be employed and the present invention specifically contemplates any such shape. In some embodiments, driver guide  300  includes a stop  247  disposed on the interior surface of the driver guide  300 . In alternative embodiments, the stop is disposed on the mechanism  226  and limits the travel of the mechanism  226 , and thereby limits the travel of the anchor mount  222 . The stop  247  prevents driving the bone anchor  230  too far into the bone.  
     [0138] In some embodiments, the mechanism  226  that translates motion to the mount  222  is a push wire  246   a.  Alternatively, the mechanism  226  could be a pull wire  248   b  as depicted in FIGS. 30A and 30B. The mechanism  226  operates on the same principle whether a push wire  246   a  or a pull wire  246   b  is used, and the following description is directed only to a push wire  246   a  for simplicity. The push wire  246   a  is coupled to the anchor mount  222  via a point contact, as shown in FIG. 29C, to advance or retract the anchor mount  222 . Alternatively, the push wire  246   a  may be secured to the anchor mount  222 . For example, the push wire  246   a  may be welded or crimped to the anchor mount  222 , in which case the push wire  246   a  must be able to twist and roll freely within the shaft  214 . In such embodiments, the actuator to push wire connection is preferably non-fixed. In alternative embodiments, the push wire  246   a  may be coupled to the anchor mount  222  via a free-floating mechanism  247 , as shown in FIG. 29D.  
     [0139] As shown in FIGS. 27A and 30A, the push/pull wire  246   a,b  is a substantially linear member that extends from the handle  212 . The push/pull wire  246   a,b  is made of a high tensile material. Suitable push wire materials include metals, plastics, and reinforced polymers. In preferred embodiments, the push/pull wire  246   a,b  is made of spring steel, or superelastic nitinol. In some embodiments, a groove or channel  248  is cut into the outer surface of the shaft  214 , extending in a line substantially parallel to the longitudinal axis of the shaft  214 . Alternatively, the groove or channel may be otherwise formed as part of the shaft  14  and may completely encapsulate the push/pull wire  246   a,b  and/or mechanism  226 , for examples see FIGS.  27 B- 27 E. The push/pull wire  246   a,b  is situated within the channel  248  disposed on the shaft  214 . In some embodiments, an actuator  224 , such as a button, lever, or trigger disposed on the handle  212 , activates the push/pull wire  246   a,b.  Force exerted on the actuator  224  is translated to the anchor mount  222  as linear force through the push/pull wire  246   a,b.    
     [0140] During insertion of the device  210  into the body, the anchor mount  222 , as well as an attached bone anchor  230 , remain in a recessed position, as shown in FIG. 29A. The sharp tip  243  of the anchor  230  therefore remains unexposed to bodily tissue. The likelihood of tearing and scraping of tissue, as well as injury to delicate abdominal organs, is thereby reduced. Because the bone anchor  230  remains protected within the hollow core  220  of the head assembly  216 , the likelihood of dislodgment of the bone anchor  230  during insertion is also reduced. The need for protective covers or sheaths for the purpose of shielding the tip  243  of the anchor is also reduced. Furthermore, when the anchor mount  222  is recessed, the profile of the head assembly  216  is reduced in comparison to the configuration where the anchor mount  222  protrudes from the head assembly  216 . Therefore, a smaller vaginal incision is required, as compared to the situation where a protective shroud or cover is provided for the bone anchor  230 .  
     [0141]FIG. 29B is an enlarged view of one embodiment of a head assembly  216  of an anchor placement device  210  of FIG. 27A, and a recessed anchor mount  222  protruding from the head assembly  216 .  
     [0142] In operation, when a force is exerted on the actuator  224  by pushing, pulling, or otherwise actuating the actuator  224 , the exerted force is translated as a linear force through the push/pull wire  246   a,b  to the anchor mount  222 . Optionally, the actuator  224  can be locked in place to prevent the anchor mount  222  from retracting. As the exerted linear force is transmitted to the anchor mount  222  through the push/pull wire  246   a,b,  the anchor mount  222  advances linearly, moving within the driver guide  300 . The attached bone anchor  230  may advance with the anchor mount  222  until halted by the optional stop  247  disposed within the driver guide  300 . In an alternative embodiment, the mechanism  226  may also actuate a force-translating mechanism (variations of which are described hereinabove), and thereby turn the anchor mount  222  in response to the applied force.  
     [0143] Having thus described certain embodiments of the present invention, various alterations, modifications, and improvements will be obvious to those skilled in the art. Such variations, modifications and improvements are intended to be within the spirit and scope of the invention. The materials employed, as well as their shapes and dimensions, generally can vary. Accordingly, the foregoing description is by way of example only and is not intended to be limiting.