Abstract:
The present disclosure relates to a graft fixation device including a body configured and arranged for passage through a bone tunnel when oriented generally longitudinally with respect to the bone tunnel, and for residing against bone defining an opening to the bone tunnel when oriented generally transversely with respect to the bone tunnel. The body defines an enclosed channel for receiving a member such that the member is substantially evenly distributed about a longitudinal extent of the body so that the body maintains a generally longitudinal orientation during passage through the tunnel, and includes a cross bar about which the member is looped when the body resides against the bone defining the opening to the bone tunnel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/783,403, filed Mar. 20, 2006, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     This present disclosure relates to tissue graft fixation.  
       BACKGROUND  
       [0003]     A ligament, such as an anterior cruciate ligament (ACL), that has ruptured and is non-repairable, is generally replaced arthroscopically by a tissue graft. The tissue graft can be harvested from a portion of a patellar tendon having so called “bone blocks” at each end, and from the semitendonosis and gracilis. Alternatively, the tissue graft can be formed from synthetic materials or from a combination of synthetic and natural materials.  
         [0004]     The replacement tissue graft is implanted by securing one end of the tissue graft in a socket formed in a passage within the femur, and passing the other end of the graft through a passage formed in the tibia. Generally, sutures are used to affix each end of the tissue graft to a fastener (e.g., an interference screw or a post), which is then secured to the bone.  
         [0005]     It is also known to use a graft fixation member, e.g., a fixation button, to secure the tissue graft at the femoral cortex, as described in U.S. Pat. No. 5,306,301 (“the &#39;301 patent”) hereby incorportated by reference in its entirety. The graft fixation member is coupled to the tissue graft and a suture, or other pulling means, is used to pull the fixation member/tissue graft combination through the bone tunnel. However, these fixation members can be cumbersome to use, due to the hole and suture loop placements on the member making it difficult to pass the graft through the tunnel. In addition, the member comes in various sizes, which makes it difficult to center the member on the top opening of the femoral tunnel. Furthermore, as the member is being drawn through the bone tunnel, the member frequently rotates off-axis, rather than maintaining a generally longitudinal orientation.  
       SUMMARY  
       [0006]     According to one aspect, a graft fixation device includes a body configured and arranged for passage through a bone tunnel when oriented generally longitudinally with respect to the bone tunnel, and for residing against bone defining an opening to the bone tunnel when oriented generally transversely with respect to the bone tunnel. The body defines an enclosed channel configured for receiving a tissue graft such that the tissue graft is substantially evenly distributed about a longitudinal extent of the body so that the body maintains a generally longitudinal orientation during passage through the tunnel, and includes a cross bar about which the tissue graft is looped when the body resides against the bone defining the opening to the bone tunnel.  
         [0007]     In an embodiment, the body includes a leading end portion defining a hole, and a trailing end portion defining a hole. In another embodiment, the trailing end portion has an open end or a closed end. In a further embodiment, the trailing end portion has a closed end wherein the closed end is angled relative to the body at an angle α, which is about 45 degrees. In yet a further embodiment, the body includes a trailing end portion having an open end and a leading end portion having an open end.  
         [0008]     In another aspect, a graft fixation device includes an intermediate portion having at least two tabs, the tabs extending transverse to the intermediate portion, the intermediate portion including at least one hole, the hole being located between the tabs.  
         [0009]     In an embodiment,, the device further includes a first end portion including at least one hole and a second end portion including at least one hole. In another embodiment, intermediate portion includes at least two holes. In yet another embodiment, the graft fixation device further includes a continuous loop of material passing through the hole of the intermediate portion. The material may include a suture.  
         [0010]     In yet another aspect, a graft fixation device includes an intermediate portion including a hinge coupled to the intermediate portion, the hinge and the intermediate portion defining a channel configured for receiving a tissue graft.  
         [0011]     In an embodiment, the device further includes a first end portion having at least one hole and a second end portion having at least one hole. In another embodiment, the hinge is U-shaped. In yet another embodiment, the hinge is rotatable relative to the fixation device.  
         [0012]     In another general aspect, a method includes looping a graft through an opening in a graft fixation device, and pulling the graft fixation device and looped graft through a bone tunnel. The graft fixation device is maintained substantially longitudinally oriented relative to the tunnel while being pulled through the bone tunnel.  
         [0013]     Embodiments of this aspect may include drilling at least one bone tunnel extending in a generally lateral direction through a knee joint. In yet another embodiment, the method further includes looping grafts through openings in multiple graft fixation devices, drilling multiple bone tunnels extending in a generally lateral direction through a knee joint, and pulling each of the graft fixation devices and looped grafts through the bone tunnels. The graft fixation devices are each configured such that the graft fixation devices are maintained substantially longitudinally oriented relative to the tunnels while being pulled through the tunnels.  
         [0014]     In a further aspect, a method includes providing a graft fixation device having an intermediate portion including at least two tabs, the tabs extending transverse to the intermediate portion, the intermediate portion including at least one hole, the hole being located between the tabs and including a continuous loop of material, drilling a bone tunnel extending in a generally lateral direction through a knee joint, looping a tissue graft through the continuous loop of material such that the tissue graft is situated between the tabs, and pulling the graft fixation device and looped graft through the bone tunnel, the graft fixation device being configured such that the graft fixation device is maintained substantially longitudinally oriented relative to the tunnel while being pulled through the bone tunnel. The material may include a suture.  
         [0015]     In an embodiment, the method further includes placing the fixation member over an opening to the bone tunnel such that the tabs extend into the bone tunnel. In another embodiment, the graft fixation device further includes a first end portion including at least one hole and a second end portion including at least one hole.  
         [0016]     In yet another embodiment, method further includes providing multiple graft fixation devices, each graft fixation device having an intermediate portion including at least two tabs, the tabs extending transverse to the intermediate portion, the intermediate portion including at least one hole, the hole being located between the tabs and including a continuous loop of material, drilling multiple bone tunnels extending in a generally lateral direction through a knee joint, looping a tissue graft through each of the continuous loop of material such that the tissue graft is situated between the tabs of each of the graft fixation devices, and pulling the graft fixation devices and looped grafts through the bone tunnels, the graft fixation devices being configured such that the graft fixation devices are maintained substantially longitudinally oriented relative to the tunnels while being pulled through the tunnels. Each of the graft fixation devices may further include a first end portion having at least one hole and a second end portion having at least one hole.  
         [0017]     In yet a further aspect, a method includes providing a graft fixation device having an intermediate portion having a rotatable hinge coupled to the intermediate portion, the hinge and the intermediate portion defining a channel configured for receiving a tissue graft; drilling a bone tunnel extending in a generally lateral direction through a knee joint; looping a tissue graft through the channel; and pulling the graft fixation device and looped graft through the bone tunnel, the graft fixation device being configured such that the graft fixation device is maintained substantially longitudinally oriented relative to the tunnel while being pulled through the bone tunnel.  
         [0018]     In an embodiment, the method further includes rotating the hinge relative to the fixation member and placing the fixation member over an opening to the bone tunnel such that the hinge extends into the bone tunnel. In another embodiment, the graft fixation device further includes a first end portion including at least one hole and a second end portion including at least one hole.  
         [0019]     In yet another embodiment, the method further includes providing multiple graft fixation devices, each graft fixation device including an intermediate portion having a rotatable hinge coupled to the intermediate portion, the hinge and the intermediate portion defining a channel for receiving a tissue graft; drilling multiple bone tunnels extending in a generally lateral direction through a knee joint; looping a tissue graft through each of the channels of the multiple graft fixation devices; and pulling each of the graft fixation devices and looped grafts through the multiple bone tunnels, the graft fixation devices being configured such that each graft fixation device is maintained substantially longitudinally oriented relative to the tunnels while being pulled through the tunnels. Each of the graft fixation devices may further include a first end portion including at least one hole and a second portion including at least one hole.  
         [0020]     In another aspect, a graft fixation device includes an intermediate portion having a prominence on a surface of the intermediate portion. The prominence facilitates alignment of a tissue graft with the device as the device is being pulled through a bone tunnel.  
         [0021]     Advantages may include one or more of the following features. Because the tissue graft or suture attached to the fixation member is preferably evenly distributed about the longitudinal extent of the fixation member, the fixation member is advantageously centered within the bone tunnel during passage through the bone tunnel, thus limiting any tendency of the fixation member to snag on the bone tunnel wall. The cross-bar, tabs, and hinge all facilitate centering of the graft or suture relative to the opening to the bone tunnel, thus limiting any tendency of the tissue graft or suture to kink against the bone cortex.  
         [0022]     The details of one or more embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present disclosure will be apparent from the description and drawings, and from the claims. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0023]      FIG. 1  shows a tissue graft secured within tibia and femoral bone tunnels during an ACL reconstruction procedure.  
         [0024]      FIG. 2A  is a side view of a fixation member shown drawing the tissue graft through the femoral bone tunnel.  
         [0025]      FIG. 2B  is a perspective view of the fixation member of  FIG. 2A .  
         [0026]      FIG. 3A  is a side view of an alternative embodiment of a fixation member shown drawing the tissue graft through the femoral bone tunnel.  
         [0027]      FIG. 3B  is a perspective view of the fixation member of  FIG. 3A .  
         [0028]      FIG. 4A  is a side view of an alternative embodiment of a fixation member shown drawing the tissue graft through the femoral bone tunnel.  
         [0029]      FIG. 4B  is a perspective view of the fixation member of  FIG. 4A .  
         [0030]      FIG. 5A  is a side view of an alternative embodiment of a fixation member shown drawing the tissue graft through the femoral bone tunnel.  
         [0031]      FIG. 5B  is a perspective view of the fixation member of  FIG. 5A .  
         [0032]      FIG. 5C  is a bottom view of the fixation member of  FIG. 5A .  
         [0033]      FIG. 5D  is an end view of the fixation member of  FIG. 5A   
         [0034]      FIG. 6A  is a plan view of an alternative embodiment of a fixation member.  
         [0035]      FIG. 6B  is a side view of an alternative embodiment of a fixation member shown drawing the fixation graft through the femoral tunnel. 
     
    
     DETAILED DESCRIPTION  
       [0036]     Referring to  FIG. 1 , during a multiple-bundle, ligament repair and reconstruction procedure, tissue grafts  200   a ,  200   b  are secured at openings  19   a ,  19   b  to femoral channels  14   a ,  14   b  within a knee  100  using graft fixation members  300   a ,  300   b , respectively. The tissue grafts  200   a ,  200   b  are tensioned at opposing ends of the channels  14   a ,  14   b  from the fixation member  300   a ,  300   b  by a surgeon and secured in place with bone anchors  20   a ,  20   b  within tibial channels  16   a ,  16   b.    
         [0037]     The use of a multiple-bundle technique, e.g., more than one femoral channel  14 , tibial channel  16 , tissue graft  200  and fixation member  300 , results in a repaired joint that is more anatomically correct than a single bundle technique, e.g., a single femoral channel  14 , tissue graft  200  and fixation member  300 . The multiple-bundle technique results in multiple anchor points to transfer stresses evenly across the knee joint and/or permits a surgeon to drill femoral and tibial channels that are more laterally oriented, closer to the joint between the tibia  13  and fibia  15 , and shallower than bone channels that are typically drilled farther away from the knee joint, and thus deeper. Further, securing the tissue grafts  200   a ,  200   b  directly to the fixation members  300   a ,  300   b  permits the surgeon to drill shallower bone channels than what may be possible when intermediate suture is used to connect a tissue graft to a fixation member, and due to the larger size of the fixation member as compared to conventional fixation members, such as the Endobutton CL, product no. 7209352, available from Smith &amp; Nephew, Inc., permits the bone tunnels to have a uniform cross-section that receives both the tissue graft and the fixation member to lie over the larger sized bone tunnel when the fixation member is positioned against the cortex at the opening to the femoral tunnel.  
         [0038]     As shown in  FIG. 2A , the tissue graft  200  is looped through an opening  350  in the fixation member  300  and is pulled through a tibia channel  16  and the femoral channel  14  using a suture  210  passed through a hole  340  defined in a leading end  300   a  of the graft fixation member  300 .  
         [0039]     During passage through the channels  14  and  16 , the fixation member  300  is oriented longitudinally within the channels. To limit any tendency of the fixation member  300  to become oriented off-axis of the channels  14 ,  16 , the tissue graft  200  is looped through the fixation member such that the tissue graft  200  is evenly distributed on either side of the fixation member  300  as the fixation member is pulled through the channels.  
         [0040]     Referring to  FIG. 2B , the fixation member  300  is an elongated member having a transversely extending cross bar  310 , a longitudinally extending trailing end portion  320 , and a longitudinally extending leading end portion  330 . The trailing end portion  320  includes a pair of rectangular arms  320   a ,  320   b  extending from the cross bar  310  and defining an open-ended, tissue graft channel  355  therebetween. The arms  320   a ,  320   b  each define one of opposing holes  321   a ,  321   b  for receiving one or more strands of suture  212 , which is used to flip the fixation member  300  after passage through the femoral tunnel  14  such that the fixation member  300  is positioned against the femur and centered about the femoral opening, as described further below.  
         [0041]     The leading end portion  330  includes a pair of rectangular arms  330   a ,  330   b  joined by a curved portion  345  which collectively define an oval-shaped, closed-end, tissue graft opening  350 . The tissue graft  200  is looped through graft opening  350  with the closed-end of the leading end portion ensuring that the graft  200  remains connected to the fixation member  300 . The curved portion  345  defines the suture hole  340 . Rather than having a closed end the leading end portion  330  may also be open, similar to the trailing end portion  320 . In this embodiment, the fixation member would be in the shape of an “H” and each end would include a pair of rectangular arms having opposing holes for receiving one or more strands of suture.  
         [0042]     The cross bar  310  acts as a fulerum for the tissue graft  200  within the bone channels after passage of the fixation member through the channels and positioning of the fixation member against the femoral cortex, as well as allowing tension to be placed on the tissue graft  200  during subsequent fixation of the tissue graft to the surface of the tibia.  
         [0043]     One or more of the cross bar  310 , arms  320   a ,  320   b ,  330   a ,  330   b  and suture openings  321   a ,  321   b ,  340  are provided with rounded or chamfered edges to provide a smooth surface for engaging with the tissue graft and/or suture, and thus limiting damage to the tissue graft or suture. By reducing the thickness of the cross bar  310  relative to the remainder of the fixation member, the graft  200  that is wrapped around the cross bar  310  can lie relatively flat as the trailing end of the graft  200  leads away from the fixation member, e.g., thereby ensuring a relatively smooth profile of the combined graft  200  and fixation member  300  within the bone channel  14 .  
         [0044]     An exemplary fixation member  300  has an overall length of between about 15 mm to about 25 mm, a width of between about 4 mm to about 9 mm, a height of between about 1 mm to about 3 mm, a width of the central bar  310  of between about 1 mm to about 2.5 mm, a length of the leading end channel  350  of between about 5 mm to about 12 mm, a width of the leading end channel  350  of between about 3 mm to about 6 mm, and a thickness of the rectangular arm portions  330   b  of between about 1 mm to about 2 mm.  
         [0045]     Other embodiments are within the scope of the following claims.  
         [0046]     For example, referring to  FIGS. 3A and 3B , an alternative fixation member  400  includes a cross bar  410  and a leading end  400   a  defining an opening  440  for passage of a lead suture  250 . Rather than including a closed-end channel and an open-ended, tissue graft channel, fixation member  400  includes a pair of closed-end channels  450 ,  455 . The tissue graft  240  is coupled to the fixation member  400  by passing a first section  240   a  of the tissue graft  240  through the first closed-end channel  450  of the fixation member  400  to form a graft loop  240   c  which includes the first tissue graft section  240   a  and a second tissue graft section  240   b . The first section  240   a  of the tissue graft is then passed around the cross bar  410  and back through the second channel  455 . Similarly, the lead suture  250  may be looped through the channel  450 , rather than being passed through the opening  440 .  
         [0047]     The fixation member  400  includes a first pair of opposing trailing arms  420   a ,  420   b  and a second pair of opposing leading arms  430   a ,  430   b . The first pair of arms  420   a ,  420   b  extend longitudinally from the cross bar  410  and are connected by a curved portion  446 . The curved portion  446 , cross bar  410  and arms  420   a ,  420   b  define the second, closed-end channel  455 . The second arms  430   a ,  430   b  extend longitudinally from the cross bar  410  in a direction opposite from the first arms  420   a ,  420   b  and are connected by a curved portion  445 . The second arms  430   a ,  430   b , the cross bar  410  and the curved portion  445  define the first, closed-end channel  450  at the leading end  400   a  of the fixation member  400 . The closed-end channels  450 ,  455  are each oval-shaped channels that are sized to accommodate the tissue graft ends  240   a ,  240   b . The suture for flipping the fixation member can be looped through channel  455 .  
         [0048]     Referring to  FIGS. 4A and 4B , an alternative fixation member  500  similar to fixation member  400  is coupled with a tissue graft  270  having first and second sections  270   a ,  270   b  forming a tissue graft loop  270   c . The fixation member  500  includes a leading end portion  500   a  and a trailing end portion  500   b , each defining a respective suture hole  540 ,  542 , with the trailing end portion  500   b  including an angled portion  505  for accommodating trailing sections of the tissue graft  270 . The angled portion  505  facilitates centering of the fixation member  500  within the channels during passage through the channels by allowing the tissue graft to be evenly distributed about the longitudinal axis of the fixation member.  
         [0049]     This fixation member  500  defines first and second, generally oval-shaped, closed-end channels  550 ,  555 . The fixation member  500  includes first arms  520   a ,  520   b  are connected by a curved portion  545 . The first arms are connected by a curved portion  546 . The first arms  520   a ,  520   b , cross bar  510 , and curved portion  546  define the channel  555 . To form angled portion  505 , each of the arms  520   a ,  520   b  is bent at an angle α, about 45 degrees, relative to the fixation member  500 , such that the curved portion  546  extends along a plane parallel to but offset to the remainder of the device. This offset provides space for the graft section  270   b  as it trails from the fixation member such that the graft is evenly distributed on either side of the fixation member allowing the fixation member to remain centered within the tunnel as it is drawn through the tunnel.  
         [0050]     Referring to  FIGS. 5A-5D , an alternative fixation member  600  is indirectly coupled to a tissue graft loop  290  by a continuous loop  281  of material passed through central suture holes  682 ,  683  within an intermediate portion  610  of the fixation member  600 . A lead suture  280  is passed through a lead suture hole  680  at a first end portion  605  of the member  600 , and a trailing suture  282  at a second end portion  620  is passed through a trailing suture hole  681 . The intermediate portion  610  includes a prominence  630  on a surface  640  of the intermediate portion  610 . The prominence  630  is in the form of a pair of transversely extending tabs  615 ,  616 . The tabs  615 ,  616  facilitate alignment of the graft  290  with the fixation member  600  thus limiting any tendency of the fixation member  600  to rotate off-axis as it is being drawn through the bone tunnel. In addition, tabs  615 ,  616  extend into the femoral tunnel when the fixation member  600  is positioned against the cortex at the opening to the tunnel, thereby centering the member  600  on the bone. The material  281  may include suture material.  
         [0051]     Referring to  FIGS. 6A and 6B , an alternative fixation member  700  includes a U-shaped, rotatable hinge  716  coupled to and extending from an intermediate portion  710  of the fixation member  700 . The U-shaped hinge  716  is a rigid, e.g., such as metallic, member which provides a movable mounting surface for directly connecting a tissue graft  294  thereto. The intermediate portion  710  and hinge  716  define a channel  730  therebetween through which the tissue graft is looped. A lead suture  292  is passed through a lead suture hole  725  at a leading, or first end  700   a  of the fixation member  700 , and another suture  293  is passed through a trailing suture hole  720  at a trailing, or second end  700   b , for flipping the fixation member  700  to position the fixation member  700  transversely to the bone channel opening. The U-shaped hinge  716  includes a pair of arms  715   a ,  715   b  and transversely extending hinge pins  711 ,  712  can be, for example, press-fit within the recesses  718  and/or pivotable about a common pin. When passed through a bone tunnel  14 , the tissue graft  294  is evenly distributed on either side of the fixation member  700  to limit any tendency of the fixation member to pivot off-axis. When the fixation member  700  is flipped after passage through the bone tunnel  14 , the U-shaped hinge  716  rotates relative to the remainder of the fixation member  700  such that the hinge  716  extends into the bone tunnel  14  while the remainder of the fixation member  700  lies against the bone surface, helping to center the fixation member  700  about the bone tunnel opening and center the tissue graft  294  within the bone tunnel  14 .  
         [0052]     Rather than coupling the tissue graft directly to the fixation member, suture attached to the tissue graft can be coupled to the fixation member. The suture can be coupled to the fixation member in the same manner as the coupling of the tissue graft directly to the fixation member, as described above.  
         [0053]     The channels can be a variety of shapes, including circular, oval, elliptical and/or rectangular. The arms can also have a variety of shapes.  
         [0054]     The leading and/or trailing ends can each be provided with one or more suture holes to facilitate positioning of the fixation member within the bone tunnel, and drawing the fixation member through the bone tunnel, and flipping the fixation member. A strand of suture can be extended between the opposing holes ( FIG. 2   b ,  321   a ,  321   b ) to serve as a stop to enclose the otherwise open end of the channel  355  to secure the trailing end of the tissue graft bundle to the trailing end of the fixation member. The graft fixation member is formed from a biocompatible material such as titanium or PEEK, or a bioabsorbable material. The tissue graft may include autograft tissue, allograft tissue, or synthetic tissue. Additionally, instead of being positioned against the outer surface of the cortex at the opening to the femoral tunnel, the fixation member may be positioned inside the bone, thereby lying against the endosteal surface of the near cortex. As described above, suture material is used. However, other material known to one of ordinary skill in the art that is strong enough to withstand pulling the fixation member/tissue graft combination through the bone tunnel could be used.  
         [0055]     Although the present disclosure relates to graft fixation members and methods of use in a multiple-bundle technique, the graft fixation members and methods can be used in a single bone tunnel technique, advantageously with the bone tunnel positioned as tunnel  200   b  as shown in  FIG. 1 .  
         [0056]     The aforementioned tissue graft fixation procedure may be applicable to other parts of the knee or other parts of the human body requiring tissue reconstruction. Accordingly, other embodiments are within the scope of the following claims. What is claimed is: