Abstract:
A surgical tensioning device for holding separated tissues in contact with one another. The device comprises a frame having two opposing first and second sides and a lower surface and an upper surface, and a band for extending around said separated tissues to be held together in conjunction with said frame. The band has two ends attached to the sides of the frame releasably. When the ends are secured to the sides of the frame, the band establishes a path of tension along its length that extends linearly between the two ends of the band.

Description:
This application claims the benefit under 35 U.S.C. 119(e) of the filing date of Provisional U.S. Application Ser. No. 61/187,846, entitled Suture Band Buckle, filed on Jun. 17, 2009, and expressly incorporated herein by reference, in its entirety. This application is also related to co-pending and commonly assigned U.S. patent application Ser. No. 12/347,821, entitled Dynamic Suture Tensioning Device, filed Dec. 31, 2008, Ser. No. 12/406,902, entitled Knotless Dynamic Suture Tensioning Device and Methods, filed on Mar. 18, 2009, Ser. No. 12/406,904, entitled Load Shaping for Dynamic Tensioning Mechanisms and Methods, filed Mar. 18, 2009, Ser. No. 12/406,909, entitled Dynamic Tissue Holding Device with Low Profile Spring, filed on Mar. 18, 2009, Ser. No. 12/836,000, entitled Flat Suture Banding System and Methods, filed on Jul. 14, 2010, and Ser. No. 12/858,332, entitled Low Friction Buckle Tightening Systems and Methods, filed Aug. 17, 2010. All of the foregoing applications are expressly incorporated herein by reference, in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention is related to the general surgical repair of separated body tissues, and more particularly to internally fixating and stabilizing such body tissues, specifically bones. 
     In the present state of the art, there are a number of systems available to repair biological tissues separated in surgery or by injury. These products serve to approximate and stabilize the tissues so that healing may commence and provide compression in the interface to promote healing. Compression and stability are critical for proper anatomical healing of tissue. With the correct amount of compression applied to the interface of the tissue portions to be joined, signals are sent to the tissue, thus allowing the tissue to remodel in proper anatomical position. The amount of compression applied to the tissue interface needs to be appropriate to the type of tissue that is being healed. 
     Twisted wires are also typically used to keep bone fragments together so they may heal. Twisted wires only hold tension as long as the twisted wire pair remains stable. Often the wires untwist too soon failing to keep the bone fragments together so that they may heal. Wires can also cut into the bone fragments allowing them to separate so that healing is difficult. 
     When it is necessary to access the thoracic cavity for a medical procedure, for example, it is required to cut the sternum into two pieces using a sternal saw. Once the procedure is completed within the thoracic cavity, the sternum must be repaired. For such repairs, it is known to use a dynamic compression device. Some of the drawbacks of this typical device, and others which are used include: 
     1. Bulky spring materials, while occupying substantial space, often do not store much energy. Some use polymer elastic bands, while other use coiled springs; 
     2. Wires are sometimes used to wrap the bones into position in compression with one another. However, wires can have sharp ends that can damage adjunctive tissues. Knot stacks in suture can interfere with the natural movement of surrounding tissues; and 
     3. Current banding systems that incorporate a biasing mechanism to achieve dynamic compression put the biasing mechanism in line with the band or suture. This practice competes with precious space at the healing site. Suture or bands are used to approximate tissues so that they may heal. It is desirable to obtain the best purchase possible on the tissue, so that the binding mechanics offered by the suture may be utilised. The best purchase is optimized by ensuring that the suture has the greatest contact area with the tissue. If a biasing mechanism is interfering with this concept, the biasing mechanism may diminish the suture&#39;s ability to hold the tissues together. 
     In addition, the current banding systems have stiff bands that are not compliant with bony undulations. Flat sutures are used, but are tedious to tie and do not hold reliably. 
     What is needed, therefore, are improved devices and techniques for holding two tissue portions in a state of compression and tension that address and overcome these shortcomings in an innovative way. 
     The banding systems of the present invention are therefore attractive for use in sternal closure because they offer some distinct advantages over the twisted wires most commonly used in the procedure. 
     Bands address the issues wires have in the following discussion. A band, by definition, is wide. In being wide, a band distributes its forces over a wider surface area. This inhibits the band from digging into the bone. In being wide, a band affords a larger cross-sectional area whereby more material may be realized thus presenting the opportunity to offer as much strength in the construct as is necessary to hold the bone fragments together. As such, bands address wire&#39;s two main weaknesses, namely, digging into the bone fragments being held together and, not having sufficient cross sectional area. 
     Bands bring in other attributes other than strength and reduced pressure on the bone. Some of these attributes are difficult to manage. With strength comes stiffness, as mentioned elsewhere herein. The larger cross-section of the band significantly increases the stiffness of the band. While stiffness and rigidity are good attributes in that they can stabilize the bone union, these attributes can also prevent the band from following the contours of the bone when inserted. This can lead to capturing tissues underneath the band that ultimately destabilize the union as the tissues continue to compress and disappear over time. 
     Binding the band ends together can also impose some problems. Generally this involves a mechanism on one band end that interfaces with holes or slots or contours on the other band end. This creates a tensioning system that is incremental in nature. As in the twisted wire system, this mechanical interface of the two ends is the weakest link in the system. This mechanical interface becomes stronger as the incremental steps become larger. But larger incremental steps aren&#39;t conducive to fine tuning the tension, so this is problematic. Flat sutures have been used to tie tissues together but the residual tension supplied in such a knotted structure is insufficient for optimum healing. There is a lot of fuss/time associated with trying to keep and hold a desirable tension with these flat sutures. What is needed is an attachment means that provides variable tensioning. 
     Another problem associated with all banding systems is that they tension by pulling asymmetrically to one side requiring constant recentering while tensioning the band. What is needed therefore is a banding system with the ability to tension symmetrically without requiring recentering of the band. 
     The present invention addresses one or more of the issues discussed above. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to a surgical tensioning device for holding separated tissues in contact with one another. 
     The present devices comprise a frame or buckle. The frame has two opposing first and second sides and a lower surface and/or lower side and an upper surface and/or upper side. The lower surface and/or lower side of the frame is the surface and/or side that is in contact with the tissue(s) being held together. In one embodiment, the two opposing first sides of the frame may be parallel to one another. The device further comprises a suture or band for extending around the separated tissues to be held together in conjunction with said frame. The suture or band has a first end, that is preferably attached or secured to the first side of the frame and a second end that is releasably securable to the second side of the frame. Thus, when the second end of the band is secured to the second side of said frame, the band establishes a path of tension along its length that extends linearly between the two ends of the band. In one embodiment, the band is sufficiently flexible to provide tension along its length. In yet another embodiment, the band or suture is substantially flat. Also, independently, in one embodiment, a needle may be secured to the second end of the band or suture of the device. Preferably, the frame or buckle has an opening that is sized appropriately to allow the passage of a needle that is secured to an end of the band or suture. In addition, the surfaces of the frame, for example, the surfaces of the interior of the frame, are adapted to guide the band so that the band can be easily threaded into the frame or buckle. As discussed below, the surface of the bar and corresponding mating surface on the frame may be textured or roughened for holding the band more securely once tensioned. 
     In one embodiment, the present device further comprises a bar or pin that is moveably attached to the second side of the frame via an attachment. The bar or pin and bar attachment are adapted to hold tension across the suture or band by pinching the second band end between the bar and the second frame side. The bar attachment is adapted to mechanically constrain movement of the bar into the inside of the frame and away from the upper surface about the second side of frame. In addition, when the bar or pin has a circular cross section, the bar attachment is adapted to prevent rotational movement of the bar once it has been engaged to pinch the second band end between itself and the second frame side. 
     In one embodiment, the bar is attached outside the second side of the frame via the bar attachment. In this embodiment, the bar attachment is adapted to mechanically constrain movement of the bar into the inside of the frame and away from the upper surface about the second side of frame. The bar can have any profile. In one embodiment, its profile is round, that is, it has a circular cross section. In the embodiment where the bar has a circular cross section, the bar attachment is adapted to prevent, in addition, rotational movement of the bar. Further, in this embodiment, the space between the first and second sides of the frame and the space between the bar and the outside of the second side may be substantially similar and sized to allow said band to pass through easily. Further, and independently, the surfaces of the bar and the outside of the second side of the frame, that is the mating surface for the bar, may be textured or roughened to provide improved performance, that is, to secure the second end of the band better relative to when the surfaces are not textured, once the band is tensioned. 
     In accordance with the device described above, when the second band end is routed around and through tissues being held together and from the bottom up through the center of the frame and over the second frame side and down between the second frame side and bar such that when second band end is tensioned and released, the bar holds the tension by pinching the band between the bar and second frame side. 
     In another embodiment, the bar is attached inside the frame at the second side of the frame via the bar attachment. In this embodiment, preferably, a support or buttress is provided inside the frame at the second frame side that includes an upper cam surface. The bar is attached at the second frame side, via a bar attachment, to the support on the upper cam surface of the support, so that the upper cam surface is contiguous with the upper surface of the frame at the second side of the frame. In this embodiment, the bar attachment is adapted to mechanically constrain movement of the bar into the inside of said frame and away from the upper surface of the frame and away from the support about the second side of frame. The bar can have any profile. In one embodiment, its profile is round, that is, it has a circular cross section. In the embodiment where the bar has a circular cross section, the bar attachment is adapted to prevent, in addition, rotational movement of the bar. The cam surface allows for supplying more leverage to the hinging attachment mechanism such that the bar can be forced harder into and be better locked inside the upper cam surface of the support against the second frame side. Further, in this embodiment, the space between the bar and the inside of the first side of the frame and the space between the bar and the inside of the second side are substantially similar and are sized to allow suture or band to pass through easily. Further and independently, the surfaces of the bar and the inside of the second side of the frame, that is the mating surface for the bar, may be textured or roughened to provide improved performance, that is, to secure the second end of the band better relative to then the surfaces are not textured, once the band is tensioned. In the embodiment of the device where a needle is attached to the second end of the band, the bar is adapted to move away from the second frame side to a sufficient distance so as to allow the needle to pass around the bar. 
     In accordance with the device described above, when the second band end is routed around and through tissues being held together and from the bottom up through the center of the frame and over the bar and down between the bar and second side of frame such that when second band end is tensioned and released, the bar holds said tension by pinching the band between the bar and second frame side. 
     In accordance with yet another embodiment of the present device is described a surgical tensioning device for holding separated tissues in contact with one another wherein the device comprises a frame with two opposing first and second sides, which are preferably parallel to each other, and a lower surface and/or lower side and an upper surface and/or upper side. The lower surface and/or lower side is the surface and/or side that is in contact with the tissue(s) being held together. The device further comprises a band or suture for extending around the separated tissues to be held together in conjunction with the frame. The band in this embodiment has a first end that is releasably securable to the first side of the frame and, a second end that is releasably securable to the second side of said frame. When the first and second ends are secured to both first and second sides of the frame, the band establishes a path of tension along its length. In addition, the band or suture is tensioned evenly utilising the two ends of the band without requiring repositioning of said frame once positioned. Such tensioning is accomplished as follows. The device comprises a first bar or pin that is moveably attached to and preferably, parallel to, the first frame side via bar attachments and, a second bar that is moveably attached to and preferably, parallel to, the second frame side via bar attachments. The first and second bars and the respective attachments are adapted to hold the tension across the suture or band by pinching the first and second band ends between the first bar and the first frame side and the second bar and the second frame side, respectively. 
     In the device described above, the first and second bars may be secured to their respective frame sides either inside or outside the frame. 
     In accordance with yet another embodiment of the invention is described a needle guide, adapted to be used in conjunction with any of the devices described above. The purpose of the needle guide is to mitigate or prevent any damage to the bars and attachments of the devices when a large needle of the kind used in these surgical repairs is used. The frame or buckle of the present devices has been designed to be small because this is a desirable quality for orthopedic implants. The needle used in these surgical repairs needs to be abnormally large so that it can pierce sternal bone. Sternal needles therefore are some of the largest needles made for threading sutures. The present needle guide removably fits or attaches to the frames of the present devices. The needle guide comprises slots, preferably integral slots so that the needle guide and slots are a single element, and is sized to fit via the slots over the bar in order to restrain the bar which, when placed over the bar, mitigates or prevents damage to the bar and bar attachment from the. 
     Once the frame of the present devices has been threaded with the suture and the bar(s) is set, the needle guide may be removed as it has no further function. This is desirable as this lowers the profile of the implant. 
     As used herein, the tissue portions to be held in contact with one another in the present invention comprise biological tissue in the body, including, but not limited to, skin, tendon, bone, ligaments, blood vessels, and organs. In one embodiment, the tissue portions comprise sternal bone that has been cut for a procedure to access the thoracic cavity. 
     The dermal layer on top of the sternum is rather thin. Even when a surgeon employs only twisted wire to repair the sternum, some patients can feel that wire under their skin. Consequently, the profile of a closure device can have cosmetic as well as practical concerns. The dermal layer over the sternum on an average adult female is 5 to 10 mm thick. A device that is ˜5 mm in height is sufficiently thick to be rather clearly seen in some adults. The profiles of the current inventive devices are spread out over a large surface area, resulting in a much more favorable aspect ratio, it will not be easily seen when viewing the patient from the outside. 
     A particularly advantageous feature of the invention is that the aspect ratio of the inventive device, defined as the height of the device above the tissue surface, divided by the length of the device, is less than or equal to approximately 0.50, and more preferably approximately 0.10. In addition, the maximum height or profile of the current inventive device at the frame preferably is about 4 mm to about 1 mm. 
     In certain preferred embodiments, the buckle or frame of the device is fabricated from either tempered stainless steel, spring tempered stainless steel or titanium. 
     In certain preferred embodiments of the present invention, the pins or bars of the device are fabricated from either tempered stainless steel, spring tempered stainless steel or titanium. 
     In certain preferred embodiments of the present invention, attachments or straps of the device are fabricated from either spring tempered stainless steel or titanium. 
     In one embodiment, the band or suture of the present devices is sufficiently flexible to provide tension along its length. In yet another embodiment, the band or suture is substantially flat. The suture or band may be defined by that which is normally available. It may be woven fibers or a monofilament and can be any material. Accordingly, the band may comprise woven, braided, or knitted fibers or metals, or a monofilament, and can be made of any known suture material. The suture may be of any shape, including, but not limited to, round, square, oval, flat (like a strap), or tubular. The shape of the suture or band for particular embodiments will be discussed more fully herein below. In one embodiment of the inventive device, the suture preferably comprises flat or tape suture. 
     On one end of the suture or band may be a needle or other receptacle to facilitate stitching or weaving in tissue or bone. Accordingly, in one embodiment, a needle may be secured to the second end of the band or suture of the device. Alternately, a needle may be secured to both ends of the suture. 
     The invention, together with additional features and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying illustrative drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view showing how wires and bands might be used in binding sternal halves together for healing after open heart surgery; 
         FIG. 2A  is a top view of a common buckle;  FIG. 2B  is a cross sectional view of the buckle in  FIG. 2A  used with a strap; 
         FIG. 3A  is a perspective view of plates used in a common buckle;  FIG. 3B  is a cross sectional view of the buckle in  FIG. 3A  used with a strap; 
         FIG. 4  is a perspective view of a buckle design where wires are used instead of plates; 
         FIG. 5A  is a perspective view of a portion of suture band buckle in accordance with an embodiment of the present invention wherein the fixed suture at one end of the buckle is shown;  FIG. 5B  is a perspective view of the suture band buckle shown in  FIG. 5A  with the suture at the both ends of the buckle shown;  FIG. 5C  is a cross sectional view of the buckle in  FIG. 5A  into which the loose end of suture has been secured; 
         FIG. 6A  is a perspective view of a portion of suture band buckle in accordance with an embodiment of the present invention wherein the fixed suture at one end of the buckle is shown;  FIG. 6B  is a perspective view of the suture band buckle shown in  FIG. 6A  with the suture at the both ends of the buckle shown;  FIG. 6C  is a cross sectional view of the buckle into which the loose end of suture has been secured; 
         FIG. 7  is a perspective view of a suture band buckle in accordance with an embodiment of the present invention, with suture and a needle attached to the suture and, a needle guide in accordance with an embodiment of the present invention;  FIG. 7A  shows the needle being guided by the needle guide into the buckle;  FIG. 7B  shows the suture and needle being guided out of the buckle; 
         FIG. 8  is an isometric view of a suture band buckle in accordance with an embodiment of the present invention, into which two loose ends of suture have been secured. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now more particularly to the drawings, there is shown in  FIG. 1  how wires and bands might be used in binding sternal halves together for healing after open heart surgery. 
     A strap locking system similar with a common buckle  1  is represented in  FIG. 2 . Referring to  FIGS. 2A and 2B , a common buckle  1 , used in straps on bags might be considered in this application for its variable tensioning abilities. Lock bar  2  moves surface  6  away from surface  8  when strap tail  5  is tensioned. As strap tail  5  is tensioned, strap tail  4  is pulled into the  6 / 8  surface interface. When strap tail  5  is released, strap tail  4  holds the dominate tension which pulls lock bar  2  so that the strap is pinched between surfaces  6  and  8 . This is the locked position of the buckle  1 . Locking bar  2  is held in position by tabs on both if its ends that ride in slot  10  which is cut out of frame  12 . Slot  10  is critical in the operation because it holds face  6  on locking bar  2  so that it correctly pinches the strap up against surface  8 . The variability of the tensions in strap tails  4  and  5  cause the lock bar to move in slot  10 . The lock bar naturally wants to even out these tensions by rotating in slot  10 . Flats are milled in the lock bar  2  ends to ride in slot  10  so that such rotation does not happen. 
     This buckle generally has the means to provide variable tensioning to the strap loop. However with a suturing system, it is necessary to have one of these strap ends free so that it may be routed through tissue with a common suture-end-needle arrangement. 
     This common buckle  1  comes pre-threaded. What would be needed to make a buckle suitable for a suture application is to have the buckle designed so that it might be threaded by the surgeon. In its common configuration, there is not enough room around locking bar  2  to fit a suture needle. 
     The distance locking bar  2  has to travel to achieve this locking and unlocking is rather small. So slot  10  provided for locking bar ends are not long. Should this be scaled down to the size of a 5 mm wide suture band, the slot only needs to be 0.020 inches long. As thus, the slot does not provide bar travel sufficient to allow a common needle, 0.065 inches in diameter, to be threaded through the buckle. Furthermore, it would be difficult to make this common buckle design open up enough to make such threading easy. Surgeons would like to see an obvious opening for the needle to pass through. 
     A strap locking system similar to common buckle  2  is represented in  FIG. 3 . This system  14  shown in  FIG. 3A  consists of two plates  16  and  18  that are joined by strap loop  20  (shown in  FIG. 3B ) at one end. Plate  16  is made smaller than plate  18  so that strap end  22  is pinched between adjoining surfaces on plates  16  and  18  when threaded as shown in  FIG. 3B  and then tensioned. The locking difference between plate system  14  and common buckle  1  lays in the pinching mechanism. Plate system  14  moves plate  16  on a hinge to lock and release strap  22 . Plate  16  can only lay parallel to plate  18  and thus the surfaces on the locking mechanism are confined to plate surfaces as managed by the hinging action. These constraints limit the effectiveness of plate system  14 &#39;s locking abilities. The pinching surfaces are commonly only lines. Common buckle  1  can have any approach to the pinching system as defined by slot  10  and pinching surfaces  6  and  8  can be of any shape. Strap locking system  14  is interesting because it can be easily threaded by a suture-needle construct. 
       FIG. 4  shows a similar buckle design as in  FIG. 3  where wires are used instead of plates. The pinching surfaces are only opposing lines on either wire. As with the plate system  14 , this wire buckle system may be threaded with the loose strap end. This works fine as long as the buckle is big enough to be manipulated with fingers. But when the buckle gets small on the scale of a 5 mm tape suture, the buckle becomes too small to manipulate for threading. 
     The present invention is directed to a strap buckle that can be threaded, has good strength holding characteristics, and is small so as to be used with suture sized straps. Furthermore, the present invention provides for holding the buckle open so that it may be easily threaded by a needle/suture construct. 
     The tissue portions to be held in contact with one another in the present invention comprise biological tissue in the body, including, but not limited to, skin, tendon, bone, ligaments, blood vessels, and organs. In one embodiment, the tissue portions comprise sternal bone that has been cut for a procedure to access the thoracic cavity. The suture may comprise woven, braided, or knitted fibers or metals, or a monofilament, and can be made of any known suture material. The suture may be of any shape, including, but not limited to, round, square, oval, flat (like a strap), or tubular. The shape of the suture for particular embodiments will be discussed more fully hereinbelow. In one embodiment of the inventive device, the suture preferably comprises flat or tape suture. 
     In certain preferred embodiments, the buckle or frame of the device is fabricated from either tempered stainless steel, spring tempered stainless steel or titanium. 
       FIG. 5  represents one embodiment of the invention. As shown in  FIGS. 5A and 5B , buckle  24  consists of frame  26  with a member  32  linked via attachments  38  to frame  26 . The member  32  is in the form of a pin or bar in this embodiment. In addition, the member  32  may be rigid. Attachments  38  are in the form of straps in this embodiment. These attachment members that link the rigid pin or bar  32  to the frame  26 , are preferably constructed to yield to slight pressure and form around frame  26 . Pin or bar  32  ultimately pinches the suture up against the inside surface  34  of frame  26 . One tail of suture or band  28 , the first end, comes attached to the frame in this embodiment. The other tail or second end of the suture or band  28  is easily threaded into buckle  24  through window  30  held open by attachment straps  38 . As tension is applied to suture tail  40 , the pin or bar  32  rotates in direction  36  to go from the outside of frame  26  to the inside of frame  26 . Attachment straps  38  yield and form around frame  26  in this process. The straps serve to hold the pin in proper position to pinch the suture against inside surface  34  when tension is released on suture tail  40 . Straps  38  also keep the bar or pin  32  from rotating. All though round bars or pins are shown up against flat surfaces in this embodiment, contoured pins with contoured mating surfaces on the pin and frame respectively, may be used to increase the buckle&#39;s holding performance. The mating surfaces, contoured or otherwise, may be further roughened or textured if more performance or better grip or holding is required. 
     In certain preferred embodiments of the present invention, the pins or bars of the device are fabricated from either tempered stainless steel, spring tempered stainless steel or titanium. 
     In certain preferred embodiments of the present invention, attachments or straps of the device are fabricated from either spring tempered stainless steel or titanium. 
     Buckle  24  has attachment straps  38  that perform the same function as slot  10  does in buckle  1  yet buckle  24  is simple enough to allow the free second end of suture  40  to be threaded through the buckle. Attachment straps  38  provide the same two functions slot  10  does in buckle  1 ; first to guide the pin into its mating locking inside surface  34 , and second to keep the pin or bar  32  from rotating in the lock. Attachment straps  38  also hold a window open to allow the threading of free suture end  40 . All though the buckles represented in  FIGS. 3 and 4  are capable of being threaded, it would be difficult to manage with gloved fingers on such a small scale. This is all done in a low profile device as is required for such surgical implants. A downsized version of buckle  1  would have a larger profile due to the material needed around the slots. 
       FIG. 6  presents another embodiment of the present invention with buckle  42  which is similar to the embodiment in  FIG. 5  in that it has the same frame  26  and bar or pin  32  and attachment straps  38 . Straps  38 , however, start in the interior of the frame instead of outside the frame. This is managed by placing buttress  46  on the interior of the frame and supplying a cam surface  44  to aid the straps in guiding bar or pin  32 . Consequently space  30  is supplied inside the frame for threading loose suture end  40 . All the same advantages are realized with buckle  42  as buckle  24 . Buckle  42  has the additional advantage of having a simple threading route whereas buckle  24 &#39;s threading route is a bit more complicated. 
     The cam surface  44  and strap  38  combination provide the same two functions slot  10  does in  FIG. 2 ; first to guide the pin into its mating locking inside surface  34 , and second to keep pin  32  from rotating in the lock. Cam surface  44  has the additional advantage of supplying more leverage to the hinging strap mechanism such that pin  32  is forced harder into and better locked inside surface  34 . All though round bars or pins are shown in this embodiment, contoured pins with contoured mating surfaces on the pin and frame respectively, may be used to increase the buckle&#39;s holding performance. The mating surfaces, contoured or otherwise, may be further roughened or textured if more performance or better grip or holding is required. 
     The design criterion for this invention is to present an easily threaded buckle to the physician. Thus far, this has been managed by opening up the buckle&#39;s architecture to allow for the suture to be threaded around pin  32 . Due to the size of pin  32  and straps  38 , the large needle needed for these procedures could easily push and bend pin  32  and straps  38  so they do not function optimally. What is needed is something that can both guide the needle around pin  32  and hold pin  32  so that the needle is not prone to disturb pin  32  and strap  38 &#39;s functionality. Such a guide should facilitate the two passes the needle needs to make to route suture  28  around pin  32 . The first pass comes up from the bottom and is the most difficult to manage as the needle is hard to see underneath the buckle. The second pass is easier to see as it originates from the top of buckle  42 . 
       FIG. 7  shows a design development of buckle  42  that presents a clear path with which needle  48  is guided around pin  32  by means of guide  50 .  FIG. 7A  shows needle  48  in this path on the way up behind pin  32 . The inner surface of guide  50  serves to provide this path behind pin  32  which is the harder of the two needle passes to manage as the needle comes up blind, underneath buckle  42 . The needle tip needs to find the interior of guide  50  and then can slide along this surface without disturbing pin  32 . Should needle  48  accidently hit pin  32 , slots  52  in guide  50  restrain pin  32 &#39;s movement so that damage is not realized to pin  32 . 
       FIG. 7B  shows needle  48  on its way down in front of pin  32 . In this configuration, visualization is much better. But still, there can be miscalculations in needle  48  movement that damage pin  32 . Guide  50  mitigates or prevents this again with integral slots  52  which serve to restrain pin  32  such that damage to pin  32  or straps  38  is not realized. 
     Buckle  42  has been designed to be small because this is a desirable quality for orthopedic implants. Needle  48  needs to be abnormally large so that it can pierce sternal bone. Sternal needles are some of the largest needles made for threading sutures. While guide  50  is effective in guiding needle  48  around pin  32 , it does not provide enough room to accommodate the large sternal needle  48 . The present invention addresses this issue in the design of slots  52 . Slots  52  in guide  50  are widened to allow lateral movement of pin  32  within the slot. This allows some of the space within guide  50  to be utilized for both the upward and downward passes of needle  48 . 
     Guide  50  is a removable element releasably attached to frame  26 . Once buckle  42  is threaded and locking pin  32  is set, guide  50  may be removed as it has no further function. This is desirable as this lowers the profile of the implant. 
     It is now evident that the present invention has created a buckle that is both easy to thread yet has a superior holding power. In miniaturizing the design, the buckle has been further modified with a needle guide to facilitate threading the buckle with larger needles. 
     It is common, in surgical procedures, to work in tight spaces that require a small vertical access to the buckle. The present invention has one buckle on frame  26  with which to tighten suture  28 . When the suture  28 &#39;s tail or end is pulled to tighten the repair, the frame  26  can be pulled off to the side. This is not acceptable, and frame  26  must be re-centered on the repair before tensioning proceeds. After centering frame  26 , tensioning proceeds but immediately pulls frame  26  off to the side again. This pulling and centering becomes a tedious process that has an easy remedy. As a remedy, described herein is one embodiment, shown in  FIG. 8 , that has two opposed sets of locking members in the form of bars or pins  32  and  32 ′ with related locking mechanisms using straps  38  and  38 ′ on frame  26  so that the two opposing suture tails or ends can be pulled in unison and secured by the respective bars or pins  32  and  32 ′ on frame  26  thus keeping the implant on center. As shown in  FIG. 8 , the bars or pins  32  and  32 ′ can be disposed inside the frame in a similar fashion as shown in  FIGS. 6 and 7 , with buttresses  46  and  46 ′ on the interior of the frame and supplying cam surfaces  44  and  44 ′ to aid the straps  38  and  38 ′ in guiding bars or pins  32  and  32 ′. In an alternate embodiment, the bars or pins  32  and  32 ′ can be disposed outside the frame in a similar fashion as shown in  FIG. 5  (this embodiment is not shown). In a preferred embodiment, the bars or pins  32  and  32 ′ and the attachments  38  and  38 ′, respectively, are substantially identical except that they are disposed on opposite sides of frame  26 . 
     While the inventive concept is disclosed as being particularly adapted for use in repairing the sternum after a thoracic cavity procedure, it is, of course, applicable to a great many other procedures requiring repair of bodily tissue, particularly bone. 
     Accordingly, although exemplary embodiments of the invention have been shown and described, it is to be understood that all the terms used herein are descriptive rather than limiting, and that many changes, modifications, and substitutions may be made by one having ordinary skill in the art without departing from the spirit and scope of the invention, which is to be limited only in accordance with the following claims.