Patent Publication Number: US-2011066185-A1

Title: Bone joint suture button and grommet and kit using same

Description:
RELATED APPLICATIONS 
     This application claims benefit of and priority to U.S. Provisional Application Ser. No. 61/201,831 filed Dec. 16, 2009, under 35 U.S.C. §§119, 120, 363, 365, and 37 C.F.R. §1.55 and §1.78 which is incorporated herein by this reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to an improved bone joint suture grommet, bone joint suture button and a bone joint suture kit using same. 
     BACKGROUND OF THE INVENTION 
     Lateral suture techniques are used to repair a wide variety of bone joint problems in humans and animals such as dogs. In one of many applications a knee joint is repaired by drilling a hole from the lateral side of the femur to the medial side and another hole is drilled from the lateral side of the tibia to the medial side. A suture is inserted through both holes and then secured to stabilize the knee joint. Over time through cycles of joint movement two serious problems arise. The suture strands saw through the bone and/or the bone wears away and weakens the suture strands. Further, bone anchors used to secure the sutures may be large and irritate the soft tissue. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide an improved bone joint button, bone joint grommet, and a bone joint suture kit. 
     It is a further object of this invention to provide such an improved bone joint button and bone joint grommet which reduce wear on the sutures and the bone. 
     It is a further object of this invention to provide such an improved bone joint which are simple and easy to install and do not present sharp, prominent edges to soft tissue. 
     It is a further object of this invention to provide such an improved bone joint suturing kit which contains the basic parts to effect a bone joint suture operation. 
     It is a further object of this invention to provide such an improved bone joint button which is chamfered or tapered where it engages the hole in the bone for a self-centering and stabilizing the button in the hole. 
     The invention results from the realization of a suture grommet having a suture passage therethrough; a head having an opening therethrough to the suture passage and a drive surface configured to receive a drive tool to set the grommet in a hole in a bone joint; the opening having its inner edge chamfered to provide a smooth continuous surface for bearing against the suture and a suture button including a body having a channel extending across at least a portion of the top surface of the body; a pair of suture passages extending from the channel inclined, inwardly to the bottom of the body; a bridge portion recessed from the body top surface between the suture passages and having a curved upper surface for providing a smooth surface for bearing against the suture. 
     The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives. 
     This invention features a bone joint suture button including a body having a channel extending across at least a portion of the top surface of the body, a pair of suture passages extending from the channel inclined, inwardly to the bottom of the body, and a bridge portion recessed from the body top surface between the suture passages and having a curved upper surface for providing a smooth surface for bearing against the suture. 
     In a preferred embodiment each suture passage may be chamfered along at least a part of its inner edge to provide smooth surfaces for bearing on the suture. Each chamfered edge may be radiused. Each body may be round. The lower edge of the body may be chamfered for a self-centering and stabilizing the body in a hole in the bone. The edge of the top surface of the body may be chamfered to avoid irritation of soft tissue. This invention also features a bone joint suture grommet including a shaft having a suture passage therethrough, a head having an opening therethrough to the suture passage and drive surface configured to receive a drive tool to set the grommet in a hole in a bone joint, the opening having its inner edge chamfered to provide a smooth continuous surface for bearing against the suture. 
     In preferred embodiment the chamfer may extend completely around the inner edge. The chamfered inner edge may be radiused. The drive surface may be on the outer edge of the head and may form a drive nut. The drive surface may include a drive member extending within and across the opening. The shaft may include external threads. 
     This invention also features a bone joint suture kit including a pair of grommets to be inserted into holes drilled in a bone, each grommet including a hollow shaft and a head portion having a top with a chamfered channel in communication with the interior of the hollow shaft, a pair of buttons each including a chamfered side wall, a top with a chamfered channel therein, and a pair of inwardly angled suture passages extending from the channel through the button and separated by a chamfered portion, and at least one suture strand looped through the pair of inwardly angled suture passages of one button over the chamfered portion and secured to a needle. 
     In preferred embodiments the kit may further include a second suture strand looped through the pair of inwardly suture passages of the second button over the chamfered portion thereof and secured to a second needle. The head portion may be configured to receive a driver for setting the grommet into a hole in a bone. The hollow shaft may include external threads. The kit may further include a tap for forming internal threads into holes drilled in the bone and may further include a driver for engaging the head portion. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which: 
         FIG. 1  is a diagrammatic, three dimensional view of a knee joint using one embodiment of the suture buttons and grommets according to this invention showing the grommets installed on the lateral side of the tibia and femur; 
         FIG. 2  is side diagrammatic, three dimensional view of the knee of  FIG. 1  from the medial side showing the suture button installed on the medial side of the tibia and femur according to this invention; 
         FIG. 3  is a three dimensional view of one embodiment of a suture grommet according to this invention; 
         FIG. 4  is a side sectional, elevational view of the grommet of  FIG. 3 ; 
         FIG. 5  is a top plan view of the head of the grommet of  FIG. 3  configured to receive an external drive tool; 
         FIG. 6  is a three dimensional view of a drive tool for engaging the grommet head of  FIG. 5 ; 
         FIG. 7  is a top plan view of another embodiment for the grommet head with a different, internal drive configuration; 
         FIGS. 8 and 9  are two different drive tools that may be used to engage with the grommet head of  FIG. 7 ; 
         FIG. 10  is a three dimensional view of one embodiment of the suture button according to this invention; 
         FIG. 11  is a side plan view of the button of  FIG. 10 ; 
         FIG. 12  is a top sectional view along lines  12 - 12  of  FIG. 11 ; 
         FIG. 13  is a side sectional view along lines  13 - 13  of  FIG. 11 ; 
         FIG. 14  is a side sectional view of a bone anchor that could be used with this invention; 
         FIG. 15  is a side elevational view of a tap that can be used in the kit of this invention; 
         FIG. 16  is a three dimensional view of a button engaged with a loop of suture strands and led by a needle used in the kit of this invention; 
         FIG. 17  is a side sectional diagrammatic view of a bone suture operation using this invention; 
         FIG. 18  is a view similar to  FIG. 17  of another bone joint suture operation according to this invention; 
         FIG. 19  is a view similar to  FIG. 17  of still another bone joint suture operation according to this invention; and 
         FIG. 20  is a view similar to  FIG. 17  of yet another bone joint suture operation according to this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer. 
     There is shown in  FIG. 1  the lateral side  10  of a femur  12  and the lateral side  14  of a tibia  16  which have been joined together using one embodiment of the suture buttons, grommets, and kit according to this invention. A hole is drilled through femur  12  from the lateral side  10  and tibia  16  through the lateral side  14 . Suture grommets  18  and  20  having heads  22  and  24 , respectively, are inserted in those holes, for example, by force fitting or they may be threaded and the holes may be tapped to threadably receive them. Heads  22  and  24  may have their corners rounded off as at  26  to prevent irritation of soft tissue. A single suture  28  having suture strands  28   a  and  28   b  extend from the proximal ends at the heads  18  and  20  and are joined by crimp  32 . 
     On the medial side  36  of tibia  16 , and medial side  38  of femur  12 ,  FIG. 2 , suture buttons  40  and  42  receive loops of suture strands  28   a  and  28   b.  Suture  28  is one continuous piece looped around buttons  40  and  42  and appears as two strands  28   a  and  28   b  in  FIG. 1 . As a part of the method of installation the strands  28   a  and  28   b  of suture  28  are pulled tight so that suture buttons  40  and  42  are pulled tight to the bone, then the tension is set on the strands and they are crimped using crimp  32 . 
     Each grommet  22 ,  24  as exemplified by grommet  22 ,  FIG. 3 , includes a head  22  containing a hole  50  which is chamfered as at  52  on the upper edge to remove the stress on the suture. Corners  26  are rounded to reduce an irritation with soft tissue and the upper edge  54  may also be chamfered or radiused for the same purpose. Hole  50  communicates with a suture passage through shaft  56  which may be smooth for a force fitting or may have threads as shown at  58  for engaging threads that are tapped in the hole in the bone. 
     Suture grommet  18  is shown in diagrammatic side sectional view in  FIG. 4  where the threads on shaft  56  have been eliminated and made smooth sided  58   a  for force fitting. Shaft  56  has a suture passage  60  through it which communicates with the hole  50  in head  22 . The chamfered inner edge  52  of hole is here shown more clearly as is its rounded or radiused profile. Head  22  may have its outer surface or periphery configured in a square or square-like shape in the form of a nut, as apparent in  FIG. 5 , for engaging with a drive tool  62 ,  FIG. 6 . Drive tool  62  contains square socket  64  for engaging head  22  and rotating or force fitting grommet  18  into the hole drilled in the bone. Head  22  can be configured with any desired shape, e.g. square, hexagonal, octagonal, to engage with the driving tool. The configuration of head  22  to engage a driving tool is not limited to an external shape: it may be internal as well. For example, there may be a drive member  70 ,  FIG. 7 , extending within and across hole  50  to be gripped by slotted tool  72 ,  FIG. 9 , having a slot in one end  74  for gripping drive member  70 . Alternatively, drive member  70  may have a slot  76  running along it which is engageable by a tool  78 ,  FIG. 8 , having a narrow bit  80  in the nature of a screwdriver. Drive member  70  is shown in phantom in  FIG. 4 . 
     Suture buttons  42  and  44  as exemplified by suture button  42 ,  FIG. 10 , has a chamfered top edge  90  and bottom edge  92  resulting in a generally convex side wall  94 . The chamfering or radiusing reduces the irritation of soft tissue. The lower chamfer or radiusing  92  is used to self center and stabilize the position of button  42  in the chamfered end of the hole drilled in the bone. Button  42  also includes a channel  96  which can be seen more clearly in  FIGS. 11 ,  12  and  13 . In  FIG. 11  the top view shows channel  96  extending across the top of button  42  and interconnecting with two suture passages  100  and  102 . Suture passages  100  and  102 ,  FIG. 12 , are inclined inwardly to converge within the body  104  of suture button  42 . Center portion  106 ,  FIGS. 11 and 12  may be radiused at both sides  108 ,  110 , again to protect the suture from wear and fraying. Channel  96  may be concave across its narrow dimension  112 ,  FIG. 13 . Channel  96  may be flat along its longitudinal extent as shown at  114  or it may be convex as shown at  116  and increasing in radius as at  118  in the center portion  106  and then reducing again to the smaller radius at  118  at the other end. If that convex contour is used then the profile as shown in  FIG. 13  will reflect the upper convex area along the channel with the concavity at  120 . The chamfer at  92  here shown as a radius nests snuggly in the chamfer  122  at the top of hole  124  drilled in the bone  125 . The mating of the chamfer  92  straight or radiused as shown and the chamfer  122  in hole  124  serves not only to automatically center suture button  42  in hole  124  but it also stabilizes it and keeps it from wobbling back and forth. 
     Although bone screws or anchors are no longer necessary when using this invention a bone anchor can be used if still desired. Such a bone anchor  130  is shown in 
       FIG. 14  with an integral drive bit  132  attached to it. Bone anchor  130  includes a head  134  with a spindle portion  136  and a through hole  138 . There is also a shaft  140  with threads  142 . In use, bit  132  is gripped in the chuck of a drill, for example, and the point  144  of bone anchor  130  is driven into the bone using bit  132  to rotate bone anchor  130 . When it is fully set, bit  132  can be wiggled back and forth as indicated by arrow  146  to cause it to snap off from head  134  at  135 . Before bone anchor  130  is driven into the bone the sutures are led in and through through hole  138  so that as the bone anchor is driven in to the bone the sutures are wound on spindle  136  to the desired tightness. 
     A tapping tool  150 ,  FIG. 15 , can be included in the kit according to this invention. Tapping tool  150  is a conventional tool with a shank  152  whose upper portion  154  is gripped in a drive tool and whose lower portion  156  contains the tapping threads. Also included in the kit according to this invention is a needle  160 , the end of which is connected at  163  to suture strands  164  and  166  of suture  162 . The other end of suture  162  forms a loop  168  which is engaged with the holes  100  and  102 ,  FIGS. 11-13 , of button  42   a.    
     The kit according to this invention may include one or more needles  160 , and sutures  162  and button  42   a  as shown in  FIG. 16 , as well as an additional button  42 , two suture grommets  18  and  20 , a tap  150 ,  FIG. 15 , and a drive tool such as drive tool  62 ,  FIG. 6 ; drive tool  78 ,  FIG. 8 , or drive tool  72 ,  FIG. 9 . 
     The apparatus of this invention may be used,  FIG. 17 , by drilling the hole  200 ,  202  in each bone  204 ,  206  shown only schematically in  FIG. 17 . The holes may be chamfered at their upper ends  208 ,  210  to receive the chamfered portion of suture buttons  212 ,  214 . At the medial end of each hole a suture grommet  216 ,  218  is set into the lateral side of each hole,  200 ,  202 , either by force fitting or threading using a tap in holes  200 ,  202  or a similar device. Then suture  219  is looped about suture button  212 , fed through the distal end  220  of suture grommet  216  and then out the proximal end  222  of suture grommet  216 . This is then led into the proximal end  224  and out the distal end  226  of grommet  218 , which is also set in the lateral side of bone  206 . Both suture strands  228 ,  230  are fed through button  214  and then tied with a knot for example  232  to draw the suture strands up tight and nest suture buttons  212  and  214  tightly against bones  204  and  206 , respectively. In another approach,  FIG. 18 , suture strands  228  and  230  are led through a bone anchor  234  after been looped around suture button  212 , fed through suture grommets  216  and  218  and through suture button  214 . In still another approach, suture  219 ,  FIG. 19 , is looped  236  through button  212  and also looped  238  through button  214 . The loose ends of strands  228  and  230  are then crimped using a crimp device  240  and crimping tool to secure strands  228  and  230 . In yet another approach,  FIG. 20 , the suture  219  is composed of two sets of strands  250 ,  252  and  254 , and  256  each of which is looped  258 ,  260  about buttons  212 ,  214 , respectively, then run through suture grommets  216  and  218  where upon all four strands  250 - 256  are secured by crimp  258 . In  FIGS. 17-20  the bones and joints are shown only schematically for clarity and the sutures and suture strands are shown loose but of course in the actual use they would be drawn up snugly to the tension required to repair the joint. 
     Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. 
     In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended. 
     Other embodiments will occur to those skilled in the art and are within the following claims.