Abstract:
An arthrodesis anchor is formed as a monolithic piece for ease of handling and use, having two ends, one of which has prongs supporting barbs extending radially therefrom. The other end may have threads or barbs. A neck between may circular in cross section and be sized from about 0.045 inches to about 0.08 inches and may be conveniently sized at 0.062 inches for bending to accommodate final alignment of joints to be bonded. Optionally, a shank next to the neck may receive a tool for threading the anchor into a joint. The proximal and intermediate phalangial joints may be trimmed and pilot drilled, after which a first end may be inserted by a tool, typically into the proximal joint by threading or linear insertion of barbed prongs. The second end having barbed prongs may then be inserted into a pilot drilled into the base of the intermediate joint.

Description:
BACKGROUND 
       [0001]    1. The Field of the Invention 
         [0002]    This invention relates to orthopedic surgery and more particularly to methods and apparatus for fixing bone elements in suitable positions for permanent healing. 
         [0003]    2. The Background Art 
         [0004]    Orthopedic surgeries originated millennia ago. Anthropological excavations have demonstrated orthopedics practices evidenced in healed, sometimes structurally reinforced, bone healing. Modern orthopedic surgery has greatly advanced the art of improving deformities through surgery. Moreover, the importance of maintaining an active life has motivated demonstrably improved methods for promoting the ability to heal. 
         [0005]    For example, patients with a variety of recovery needs were customarily committed to bed rest in hospitals in decades past. Modern medicine realizes the emotional and physical toll that such inactivity takes on a patient. Modern surgical techniques acknowledge the importance of maintaining a physically active body as a mechanism to aid in healing processes. Accordingly, it is desirable to have patients continue in their daily movement and activities as soon as possible. To this end, less invasive surgical techniques have been developed. 
         [0006]    Likewise, structural implants such as plates, screws, staples, rods, pins and the like have been augmented by new joint systems, and other orthopedic implants to replace or enhance natural orthopedic structures in the body. 
         [0007]    Nevertheless, surgical techniques need to be simplified in many instances. Likewise, the speed at which surgical procedures can proceed is limited by both the physical circumstances of the injury or malady being corrected, as well as the equipment used, and any other supporting equipment or devices required by the procedure. 
         [0008]    Accordingly, it would be an advance in the art to provide implants, such as orienting pins, screws, attachments, and the like in a way that provides faster installation, more secure holding, post-installation adjustment, and the like. Such features would provide to a surgeon the additional benefit of being able to confirm securement, adjust angles of relative positioning between adjacent bone elements, and do so late in the procedure, as a feedback-controlled final adjustment. 
         [0009]    For example, it would be an advance in the art if a surgeon were able to adjust the angle of two bones being conjoined for a hammertoe surgery Likewise, it would be an advance in the art to provide robust, strong, and yet bendable or otherwise adjustable portions of a bone anchor in order that a doctor could survey his handiwork near the close of an operation, and readjust angles, proximities, and the like before closing up the incisions. 
         [0010]    It would be a further advance in the art if the attachment mechanisms for such an inter-element anchor were sufficiently strong and engaged that the bone elements being anchored could themselves serve as the handles in order to support the final orientation thereof after the anchor has been placed. It would also be an advance if the anchor could support three dimensional stability following surgery in order to hasten healing, permit early use promoting circulation and healing, and otherwise provide securement with less threat of separation, twisting, disorientation, and the like during the important early days of the healing process. 
         [0011]    It would be a further advance of the art to provide three dimensional stabilization between two elements being joined in an orthopedic, and particularly a hammertoe remediation, by providing reliable anchoring in the longitudinal direction, as well as orientation in the lateral and transverse directions orthogonal thereto in order that healing begin early and be promoted by stability of the joint in all three dimensions. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    In view of the foregoing, in accordance with the invention as embodied and broadly described herein, a method and apparatus are disclosed in one embodiment of the present invention as including a method for controlling application of an anchor may be based on facts corresponding to the entity controlling the application. 
         [0013]    In one embodiment of an apparatus and method in accordance with the invention an orthopedic anchor, particularly one adapted to arthrodesis, may include two ends of a single, solid member. A first end may be threaded with flutes adapted to be threaded into a pilot hole formed to extend into the medullar portion of a bone segment. Typical bone segments may include the proximal and intermediate phalangial joints of a patient, such as a patient having a hammertoe deformity. 
         [0014]    The flutes of the threads may be sized in pitch and depth to promote gripping of the flutes against not only the structural portion of the marrow or medullar portion of the bone segment into which penetrating, but also to engage the cortical portion of the bone in order to provide a secure longitudinal attachment. Accordingly, the length and diameter may be sized to engage the cortical region, and the placement may be selected in order to optimize this engagement. 
         [0015]    The opposite end of the anchor may be formed as an array of barbed flutes providing a substantially rectangular cross section. As a practical matter, the barbs may actually be considered circular, but typically having flats formed in diametrically opposed sides. Thus, the fluted, arcuate portions of the barbs may extend laterally in one dimension, but be absent at ninety degrees therefrom. 
         [0016]    Likewise, a slot may be formed in the barbed end of the anchor to extend between the two flat aspects of the barbed end. In this way, a tool may be fitted against the flats, having a web connecting between the flats, and extending through the slot formed between the barbs. Various other webs may be formed in tool or barbs in order to stabilize the two prongs or legs of the barbed end with respect to one another, minimize the unsupported length thereof, and the like. 
         [0017]    Between the threaded or screw end of the anchor and the barbed end thereof, a hexagonal or other tool-shaped portion or shank may extend. This portion may permit or admit access by a tool for turning the anchor once in place Likewise, engagement by a tool for driving may also be supported by a shaped, typically a hexagonal, cross section thereof. 
         [0018]    In one apparatus and method in accordance with the invention, the tool-receiver portions of the shaped (e.g., hexagonal) portion proximate the screw end on the anchor and the slotted driver-receiver portion between the flutes of the barbed end of the anchor may include a neck portion having the minimum diameter available in the anchor. Accordingly, this neck portion, having the minimal diameter, therefore has the smallest section modulus along the length of the anchor. This portion, when formed to be of circular cross section, has the ability to be angled in any direction of the axial center or longitudinal axis. 
         [0019]    Thus, a surgeon may put a bend in the neck of the anchor prior to the final installation, or at any time. In one embodiment of a method in accordance with the invention, a surgeon may maintain the anchor completely straight throughout the surgery, and then provide any angular adjustment in any desired direction by bending the anchor in that direction. 
         [0020]    Accordingly, a surgeon may maintain surface alignment and contact between the resected contact faces of the bone elements being joined Likewise, those faces may be canted slightly with respect to one another in order to maintain the desired orientation, thus relying on the bones to fill in any misalignments of the faces, in order to support longitudinal alignment of the bone elements in this surgical procedure. 
         [0021]    In certain embodiments of an apparatus and method in accordance with the invention, an anchor may be pre-angled between the barbed end and the threaded end. In such an embodiment, a tool may be provided that is exactly matched to any “misalignment” of the angle of the barb with respect to the longitudinal axis of the screw. In such an embodiment, for example, the tool may have matching angles provided. 
         [0022]    The front end and engagement portion of the tool first angles away from the longitudinal axis of the tool, in order to obtain a distance of angle required to support the angle of the barb. Then, the tool angles again directly down the length of the barb, thus providing axial alignment between the handle of the tool and the longitudinal axis of the screw end. 
         [0023]    In this way, the tool provides a “dogleg” effect in which the screw is axially aligned along a longitudinal axis, and the handle is collinear therewith. Meanwhile, between the handle of the tool and the threaded end of the anchor, a dogleg angles out away from the longitudinal axis, and then back in towards the longitudinal axis, aligned exactly with the longitudinal axis of the barbed portion by which the tool engages the anchor. Meanwhile, the handle end of the tool aligns at all times with the screw. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The foregoing features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings in which: 
           [0025]      FIG. 1  is a perspective view of one embodiment of an apparatus in accordance with the invention including both an anchor and a tool for manipulating the anchor during initial stages of the installation process; 
           [0026]      FIG. 2  is a perspective view of the anchor and tool of  FIG. 1 , viewed from the opposite end thereof; 
           [0027]      FIG. 3  is a top plan view of the anchor of  FIG. 1 ; 
           [0028]      FIG. 4  is a bottom plan view thereof; 
           [0029]      FIG. 5  is a left side elevation view thereof; 
           [0030]      FIG. 6  is a right side elevation view thereof; 
           [0031]      FIG. 7  is an end elevation view from the screw point end; 
           [0032]      FIG. 8  is an end elevation view thereof showing the pronged or barbed end that is engaged by the tool; 
           [0033]      FIG. 9  is a perspective view of one embodiment of the tool of  FIG. 1 , having the center portion shortened as indicated in order to provide detail of the handle and anchor ends thereof; 
           [0034]      FIG. 10  is a top plan view of the tool of  FIG. 9 ; 
           [0035]      FIG. 11  is a bottom plan view thereof; 
           [0036]      FIG. 12  is a left side elevation view thereof; 
           [0037]      FIG. 13  is a right side elevation view thereof; 
           [0038]      FIG. 14  is an end elevation view of the screw engagement end of the tool of FIGS.  1  and  9 - 13 ; 
           [0039]      FIG. 15  is an end elevation view of the tool of FIGS.  1  and  9 - 14 , from the handle-end thereof; 
           [0040]      FIG. 16  is a perspective view of the anchor of  FIGS. 1-6  showing the process of engagement thereof with a bone joint; 
           [0041]      FIG. 17  is a perspective view of the anchor of  FIG. 16 , as the barbed end thereof is inserted into the bone joint that is to be fused with the first bone joint; 
           [0042]      FIG. 18A  is a perspective view of an alternative embodiment of the tool of  FIGS. 1 and 9 , designed to accommodate threading of the screw portion of the anchor into a bone joint when the anchor has been formed with a pre-defined bend angle between the barbed portion and the threaded portion of the anchor; 
           [0043]      FIG. 18B  is a side elevation view thereof with an anchor in place ready for insertion; 
           [0044]      FIG. 18C  is a side elevation view of an alternative embodiment of the tool of  FIGS. 18A-18B ; 
           [0045]      FIG. 19  is a perspective view of an alternative embodiment of an anchor in accordance with the invention, not relying on a hexagonal shank; 
           [0046]      FIG. 20  is a perspective view from the opposite end thereof; 
           [0047]      FIG. 21  is a top plan view thereof; 
           [0048]      FIG. 22  is a bottom plan view thereof; 
           [0049]      FIG. 23  is a left side elevation view thereof; 
           [0050]      FIG. 24  is a right side elevation view thereof; 
           [0051]      FIG. 25  is an end elevation view from the screw end thereof; 
           [0052]      FIG. 26  is an end elevation view from the barbed end thereof; 
           [0053]      FIG. 27  is a perspective view of an alternative embodiment of an anchor in accordance with the invention relying on two barbed ends rather than a screw; 
           [0054]      FIG. 28  is a perspective view thereof from the opposite end, and rotated at right angles about a longitudinal axis; 
           [0055]      FIG. 29  is a top plan view of the embodiment of  FIG. 27 ; 
           [0056]      FIG. 30  is a bottom plan view thereof; 
           [0057]      FIG. 31  is a left side elevation view thereof; 
           [0058]      FIG. 32  is a right side elevation view thereof; 
           [0059]      FIG. 33  is an end elevation view thereof from the back end having fewer barbs; 
           [0060]      FIG. 34  is an end elevation view from the opposite end thereof; 
           [0061]      FIG. 35  is a perspective view of an alternative embodiment of an anchor in accordance with the invention relying on two barbed ends, and having a pre-formed bend angle between the longitudinal axes thereof; 
           [0062]      FIG. 36  is a perspective view thereof from the opposite end, and rotated at right angles about a longitudinal axis; 
           [0063]      FIG. 37  is a top plan view of the embodiment of  FIG. 35 ; 
           [0064]      FIG. 38  is a bottom plan view thereof; 
           [0065]      FIG. 39  is a left side elevation view thereof; 
           [0066]      FIG. 40  is a right side elevation view thereof; 
           [0067]      FIG. 41  is an end elevation view thereof from the back end having fewer barbs; and 
           [0068]      FIG. 42  is an end elevation view from the opposite end thereof. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0069]    It will be readily understood that the components of the present invention, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of various embodiments of the invention. The illustrated embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. 
         [0070]    Referring to  FIG. 1 , while referring generally to  FIGS. 1-42 , a system  10  or apparatus  10  in accordance with the invention may include an anchor  10  that may be manipulated and applied using a tool  11 . The anchor  10  includes a screw portion  12  or a screw  12  formed in a unit with a barb portion  14  or barb  14 . In the illustrated embodiment, the screw  12  and barb  14  portions are formed together of a single, homogeneous material simultaneously formed in any suitable manner. 
         [0071]    For example, a screw machine may form such devices, but stamping may also produce similar products. Thus, a suitable manufacturing method may apply. 
         [0072]    In certain embodiments, the apparatus  10  may be formed to be of a biodegradable material. Nevertheless, in other embodiments, durable materials that are not rejected by the body may be used. For example, stainless steel, titanium, and the like have been found suitable for applications useful for anchors  10  in accordance with the invention. 
         [0073]    The anchor  10  may also be formed to include a shank  16  or a shank portion  16 . In certain embodiments, it has been found that the shank  16  is best located immediately adjacent the screw portion  12 . In application, the screw  12  may be threaded into a portion of bone, typically the medullar portion. Accordingly, the shank  16  may follow the screw  12  into the medullar portion of a bone joint segment with the shank  16  sunk into the bone until the end of the shank  16  farthest from the screw  12  is flush with the surface thereof. 
         [0074]    In some embodiments, the shank  16  may be shaped in any suitable shape to stabilize the screw  12  against turning. That is, as healing begins a non-circular shape resists any tendency of rotation between adjacent joints that will be anchored together by the anchor  10 . In certain embodiments, the shank  16  may be formed in a hexagonal polygon cross section in order to form edges that are not round. This way, as the tissue grows back to replace itself about the shank  16 , the shank  16  is further stabilized, and acts to stabilize the anchor  10 . 
         [0075]    Likewise, in some embodiments, the shank  16 , if formed as a polygon, particularly as a hexagon, may also be used to engage a tool  11 . Thus, the shank  16  may operate like a nut or the head of a bolt to engage a tool  11  used to rotate the shank  16 , in order to thread the screw  12  into a segment of bone. 
         [0076]    In addition to the shank  16 , the anchor  10  may include a shaft  18  between the screw portion  12  and the barb portion  14 . In the illustrated embodiment, the shaft  18  fits between the shank  16  and the barb portion  14 . The length and diameter of the shaft  18  are selected in certain embodiments to support bending. For example, a surgeon in using an anchor  10  in accordance with the invention may determine in advance to bend the shaft  18  after the anchor  10  has been installed, both with the screw portion  12  and the barb portion  14 . Accordingly, last in its alignment, whether angular in nature, or whether a closer fit between the contacting adjacent surfaces of bone may be desired, the shaft  18  may be bent in order to provide any last minute adjustments according to the desires and recommendations of an attending surgeon. 
         [0077]    In other embodiments, the shaft  18  may be pre-angled in order to provide a known and desired angular difference between the orientation of the screw portion  12  and the barb portion  14  of the anchor  10  once installed. In this way, a pre-determined angle may exist in the shaft  18 . If the pre-determined angle is to be further modified, the shaft  18  may still be further bent in any suitable direction. Thus, whether laterally or transversely (at a right angle thereto) with respect to a longitudinal axis of a bone joint, the shaft  18  may be realigned or angled according to the desires of a surgeon. 
         [0078]    In the illustrated embodiment, an anchor  10  may include a slot  20 . The effect of the slot  20  is to form the barb portion  14  into a cantilevered, pronged arrangement. Also, the slot  20  may serve to engage the tool  11  in order to drive the screw portion  12  into a bone joint for a surgery. The slot  20  may also provide a region in which tissue will reform and fill up, further stabilizing the anchor  10  once in place. Typically, an anchor  10  is not removed. Rather, the anchor  10  stabilizes a surgery, and remains in place after healing is complete. 
         [0079]    The screw portion  12  may include threads  22  at a selected pitch, depth, advance angle, and the like. Moreover, the threads  22  may be buttressed such that they tend to be supported more against force or deflection in one direction than another. For example, in one embodiment, the threads  22  may be thought of as flutes that have a longer rise and cross section on the forward end, as the screw  12  advances, and a more precipitous cut, even an undercut, on the side of the thread  22  away from the direction of advancement. 
         [0080]    By the same token, the barb portion  14  may include a plurality of barbs  24 , the barbs may act on cantilevered arms in order to pass through a pilot hole, and then work out into the medullar region of the bone, ultimately engaging the cortical portion thereof. Likewise, the threads  22  are best engaged into cortical material of the bone, the outer shell like portion that is more dense, stronger, and much harder than the medullar or central region of the marrow. 
         [0081]    In order to facilitate an insertion, the screw end  12  or screw  12  may have a point  26 . The point  26  may actually not come to a literal physical point, but may be truncated. One reason why a point may not be required is that a pilot hole will typically serve well to minimize trauma, aid healing, and reduce pain. Stress in a bone translates to pain during recovery. Thus, a pilot hole may be drilled in a bone segment, and the point  26  need only accommodate that pilot hole. Accordingly, the point may be sized to engage the pilot hole, which also may be countersunk in order to receive the point  26 , whereupon the threads  22  will engage the bone and advance the screw portion  12  thereinto. Also, the screw  12  may be hollow. Thus it would not form a sharp point  26 . 
         [0082]    Likewise, the barb portion  14  may include a point  28  associated with the first of the barbs  24 . Like the opposite end  12  of the anchor  10 , the point  28  at the barb portion  14  of the anchor  10  may be sized to fit or otherwise engage a countersink in a pilot hole. Likewise, a pilot hole could be simply drilled at a single diameter, and the barb point  28  may engage that pilot hole. 
         [0083]    Referring to  FIGS. 1-8 , and more generally to  FIGS. 1-42 , an anchor  10  in accordance with the invention may be provided with cavities  30  configured to receive tissue growth therethrough. Thus, several functions may be met. In one manner, the conservation of mass principle requires that mass be neither created nor destroyed. Typically, except in circumstances of gases, the material will remain comparatively incompressible. 
         [0084]    In the illustrated embodiment, the central portion of the screw portion  12  of the anchor  10  may be hollow. Accordingly, the effect of the point  26  of the screw portion  12  is effectively to cut and separate a core of the medullar portion of the bone, which then passes into the inner diameter of the screw portion  12 . Therefore, some type of venting is appropriate. The cavities  30  extend from the outer portion of the shank  16  to the inner portion of the screw portion  12  of the anchor  10 . Thus, air and liquids may be pistoned or swept through and out of the center portion of the screw  12 , exiting by way of the cavities  30  formed in the shank  16 . 
         [0085]    The screw  12  may have an outer diameter  32  defining the outermost edge of the flutes or threads  22  thereof. Meanwhile, the outermost diameter  34  of the barbed portion  14  will typically follow an arcuate path, although not usually for a full circle. That is, the barbs  24  are formed to present a flat aspect  21  that assists in stabilizing the barbs in place, reduces the requirement in the size of the pilot hole required, and also provides for cantilevering of the barbs  24  in order that they may ultimately extend to their maximum outside diameter  34  to engage the cortical portion of the bone. 
         [0086]    Meanwhile, the threads  22  have an inner diameter  36  that defines the valley, trough, or the relief that exists at a lesser diameter than the outer diameter  32  of each of the flutes  22  or threads  22 . Moreover, the screw  12  may also have an innermost diameter  37  that represents a cavity formed or a tubular vacancy in the center of the screw  12 , so that the screw  12  effectively passes or even cores a portion of the material from the medullar region of the bone upon insertion thereinto. 
         [0087]    As with the screw portion  12 , the barbed portion  14  has an outer diameter  24  as well as an inner diameter  38 . The inner diameter  38  provides for additional material, provides for a smooth and arcuate surface, and provides additional stiffness for the barb portion  14 . Effectively, the barb portion  14  is divided into two prongs  40 . Each of the prongs  40  contains an array of barbs  24 , the first one representing the point  28 . 
         [0088]    Thereafter, the barbs may increase in diameter or rather have a larger outer diameter  34  than the first barb. Thus, just as each of the threads  22  has an outermost diameter  32  and an inner thread diameter  36 , each of the barbs  24  has an outer diameter  34  at which it engages the bone, and an inner diameter  38  that represents effectively the beam that cantilevers or carries the barb  24 . That beam is one of the prongs  40  arrayed with barbs  24  there along. 
         [0089]    Thus, each of the threads has a gap  42  or pitch  42  between threads. Similarly, each of the barbs  24  has a pitch  44  or gap  44  in which it receives material. That is, the threads  22  actually wend their way through bone material and leave it largely in place and fill in the gaps  42  between the threads  22 . 
         [0090]    In contrast, the gaps  44  may be less filled with bone material inasmuch as the barbs  24  must pass therethrough. However, the cantilevered effect of the prongs  40  permits the barbs  24  to move toward one another, forced by the pressure of the surrounding bone. Nevertheless, upon the slightest provocation to retreat, or upon coming to rest, the prongs  40  are urged apart by their inherent elasticity, causing each of the barbs  24  to move out toward its edge  48 . The edges  46  of the screws  12  or the edges  46  of the threads  22  will cut into and anchor against the bone material, and particularly against cortical material. Likewise, the edges  48  of the barbs  24  will tend to advance outward as they come to rest, cutting through the medullar material and engaging the cortical material of the bone. 
         [0091]    Referring to  FIGS. 9-15 , while continuing to refer generally to  FIGS. 1-42 , a tool  11  in accordance with the invention may be formed to fit over the barb portion  14  of an anchor  10 . Accordingly, opposite the received portion of the tool  11 , a handle portion  52  may be adapted to be gripped by a hand of a surgeon. For example, the handle portion  52  may include a flat  56  as well as relief  62  for gripping. 
         [0092]    Any time relief is provided, such as by notching, knurling, or the like, the handle portion  52  may be more readily gripped because flesh from the hand of a user expresses into the slot or relief area providing better than a frictional grip thereon. Accordingly, the tool  11  may include a flat  56 , a relief slot  62 , knurling, or the like in order to provide better grip of the tool  11  for a surgeon. Accordingly, a surgeon user may thereby rotate with greater security the tool  11  in order to thread the anchor into a bone joint where the anchor  10  will serve to stabilize the conjoining of two joints during healing. 
         [0093]    Likewise, the anchor portion  54  or the receiving portion  54  of the tool  11  may include a slot  58  to receive the barb portion  14  of the anchor  10 . Specifically, the prongs  40  that form the main beams  40  of the barb portion  14  may fit within the slot  58 , sized to receive it. 
         [0094]    Similarly, a web  60  may extend between opposite faces of the slot  58  in order to engage the slot  20  in the anchor  10 . Thus, the barb portion  14  is engaged on the flats  21  by the opposing faces that form the slot  58 . Meanwhile, the slot  20 , and the inner faces of the barb portion  14  that form the slot  20 , are engaged by the web  60 . 
         [0095]    Moreover, in certain embodiments, a relief  64  may be formed to receive the hexagonal or other shape of the shank  16 . Thus, the anchor  10  may be engaged by the tool  11  by the slot  58  engaging the flats  21  of the barb portion  14 , the web  60  engaging the faces of the slot  20  in the barb portion  14 , and the relief section  64  or a hexagonal relief  64  fitted to the shank  16  engaging the shank. 
         [0096]    Referring to  FIGS. 16-17 , while continuing to refer generally to  FIGS. 1-42 , the use of an anchor  10  and the tool  11  in a surgical operation may include several distinct steps. Some may be done simultaneously, and some may be executed sequentially. 
         [0097]    As a preparatory matter, the face  68  of a first bone joint  70  may be trimmed, or resected in order to render the joint  70  capable of joining with another portion of bone. That is, so long as the outermost layer of the joint  70  remains intact, it will not tend to heal with another bone. However, by resecting the face  68  slightly toward the bone joint  70 , the face  69  will then be in a condition to heal against another portion of bone. A face  72  of a second bone joint  74  is likewise resected in order to trim it and prepare it to heal against the first joint  70 . 
         [0098]    Initially, the bone-joints may be drilled with pilot holes. Then, the anchor  10  is placed in the tool  11 . The tool is rotated as the screw portion  12 , and particularly the point  26  thereof, is urged into the pilot hole of the first bone joint  70 . The tool  11  is rotated, by gripping the flat  56  on the handle portion  52 . 
         [0099]    Accordingly, the threads  22  spiral into the medullar portion of the first bone joint  70 , until the shank  16  is effectively buried flush with the surface  68  or face  68  of the joint  70 . The tool  11  may then be removed. The tool  11  has engaged the barb portion  14  of the anchor  10 , thus using the barb portion  14  as an engagement region or as a head for the engagement by the tool  11  of the screw  12 . 
         [0100]    Upon withdrawal of the tool  11  along a longitudinal axis of the barb portion  14 , the tool  11  may be removed Likewise, as the screw  12  was turning into the face  68  of the joint  70 , the face  68  eventually pushes the tool  11  back and off the shank  16 , thus disengaging the relief portion  64  of the tool  11  from the shank  16  of the anchor  10 . 
         [0101]    Once the tool  11  has been withdrawn, the barb portion  14  is exposed and projecting from the joint  70 , and particularly from the face  68  thereof. A pilot hole, previously or now drilled into the face  72  of the joint  74  provides a certain amount of relief, and directional piloting of the barb portion  14 . Thus, the surgeon may then push the point  28  of the barb portion  14  into the pilot hole. 
         [0102]    Thus the screw  12  is initially guided and engaged in the pilot hole  76  in the first joint  70 . Meanwhile, at this next stage, the barb portion  14  is driven by force into the pilot  78  in the second joint  74 . The cantilevered prongs  40  will move toward one another, thus providing relief on the edges  48  of the barbs  24 . However, upon any tendency to come to rest, or to be withdrawn, each of the edges  48  immediately cuts and drives outward due to the undercut shaping thereof. Thus, the barbs  24  provide a positive holding of the second joint  74  against the first joint  70 . 
         [0103]    At this point, the faces  68 ,  72  are typically in full plane or contact. Inasmuch as each of the faces  68 ,  72  is resected, typically by a saw or other tool that is capable of forming a planar surface  68 ,  72  then alignment of the faces  68 ,  72  is preferred for best healing. Nevertheless, in order to obtain that alignment, a surgeon may bend the anchor, at the shaft  18  in order to provide that alignment. 
         [0104]    Moreover, other considerations may also be at play. The surgeon may determine that slight rotation is necessary, and a rotation of the joint  74 , or even of the joint  70  will provide rotation of the screw portion  12  with respect to the joint  74 . Thus, rotational alignment may be modified slightly if desired. Moreover, any type of lateral or transverse alignment, that is, alignment movements in any radially direction or orthogonal to the longitudinal axis of the anchor  10  may also be made by bending the shaft  18 . 
         [0105]    The shaft  18  may be bent by simply providing relative motion in any radial direction between the joint  70  and the joint  74 , by the manipulation of either one with respect to the other. Thus, one may be held still while the other is angled. In this manner, an anchor  10  in accordance with the invention may provide additional benefits by providing last minute inspection of the surgery, and slight modifications or the angular relationships and rotational relationships between the joints  70 ,  74 , in order to obtain the best result. 
         [0106]    Referring to  FIGS. 18A-18C , while continuing to refer generally to  FIGS. 1-42 , in an apparatus and method in accordance with the invention, a tool  11  may be formed to service an anchor that has a pre-determined offset angle between the longitudinal axis of the screw portion  12 , and the longitudinal axis of the barb portion  14  of the anchor  10 . In one embodiment of an apparatus and method in accordance with the invention, a tool  11  may be formed to receive an anchor  10  having a pre-determined angle of bending of the shaft  18  thereof. 
         [0107]    Thus, two angles  82 ,  84  may be formed near the anchor portion  54  of the tool  11 . A first angle  82  provides the angle required to accommodate a barb portion  14  of an anchor  10 . Placing an anchor  10  into the anchor portion  54 , and the slot  58  particularly, of the tool  11 , the screw portion  14  is aligned with the handles  52 . The longitudinal axis thereof is in alignment, and in fact collinear with, the longitudinal axis of the handle portion  52  of the tool  11 . 
         [0108]    In order to connect the anchor portion  54  of the tool  11  to the handle portion  52 , an angle  84  opposite the angle  82  must be made in the tool  11 . This takes back out of the tool  11  the angle  82  included for accommodation of the barb portion  14 . This is an equal and opposite offset angle from the longitudinal axis of the screw portion  12 . Upon rotation of the handle portion  52  by a surgeon, the tool  11  rotates about its own longitudinal axis, which is collinear with the longitudinal axis on the screw portion  12 . Upon completing of the threading portion of the process of inserting the anchor  10 , a surgeon may draw the handle portion  52  away from the anchor  10 , and thus remove the slot  58  and web  60  from engagement with the barb portion  14  of the anchor  10 . 
         [0109]    Referring to  FIGS. 18A-18C , the tool  11  may be conformed to the procedures of placing an anchor having a pre-determined angle offsetting the screw portion  12  from the barb portion  14 . Thus, in  FIGS. 18A ,  18 B, a rod may be formed with two bends, at the respective angles  82 ,  84  in order to position the screw portion  12  of an anchor  12  in alignment with the handle portion  52 . 
         [0110]    However, line of sight alignment may be enhanced if the handle progresses continuously in the longitudinal direction. Thus, with the screw portion  12  extending therefrom as in  FIG. 18C , natural line of sight and natural eye-to-hand coordination may aid orientation of the tool  11 . The additional clearance during a rotational sweep of the tool  11  as it threads the screw portion  12  into a joint  70 ,  72  will effectively be the same in all such embodiments. 
         [0111]    Extraction of the tool  11  after installation of the anchor is along the longitudinal axis of the barb portion  14 . For example, the slot  58  of the tool disengages from the flats  21  of the barbs  24 , while the slot  20  of the barb portion  14  disengages from the web  60  of the tool  11 . 
         [0112]    Referring to  FIGS. 19-26 , in some embodiments of an apparatus and method in accordance with the invention, an anchor  10  need not have the shank  16 . In this embodiment, the flats  21  on the barbs  24  are engaged by the slot  58  of the tool, and the slot  20  of the anchor  10  is engaged by the web  60  of the tool. However, the shank  16 , being absent, is not engaged by the relief  64  in the tool  11 . The installation of such an embodiment progresses the same as that of previously described embodiments. 
         [0113]    Stability against rotation is provided by the flats  21  of the barbed portion  14 . Stability in a longitudinal direction is provided by the threads  22  and the barbs  24 . Final adjustments in a longitudinal direction may be made by advancing the joints together, further advancing the barbs  24 . Rotational adjustments may be made by rotating the joint holding the barb portion  14  with respect to the joint holding the screw portion  12 . Angular adjustments may be made by bending the anchor at the neck  18  or shaft portion  18 . 
         [0114]    Referring to  FIGS. 27-34 , in certain embodiments, an anchor may include both ends as barbed portions  14 . In this embodiment, insertion of the anchor with the tool  11  may by done by a longitudinal push of the first set of barbs  24  into the pilot hole  76  in response to force applied to the tool  11 . Thereafter, the second set of barbs  24  may be inserted into the second pilot hole  78  by pushing the pilot hole  78  in the joint  70  onto the second set of barbs  24 . Rotational adjustment is more difficult and damaging, unless accomplished before setting the second set of barbs  24 . Angular adjustments may be made by bending at the neck  18 . 
         [0115]    Referring to  FIGS. 35-42 , a pre-set angle may be formed in the anchor  10 , regardless of which types of ends  12 ,  14  are used. Accordingly, the apparatus and method of this embodiment may be employed in a manner similar to that for the embodiment of  FIGS. 17-24 . Typical preset angles may be used to accommodate a need for modifying the relative angle between two joints. 
         [0116]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.