Abstract:
A device for surgically coupling a soft tissue graft into a tunnel of a bone. The device includes a first member and a second member. The first member includes a first graft-engaging surface extending from a first end to a second end of the first member. The second member includes a second graft-engaging surface extending from a first end to a second end of the second member. The first graft-engaging surface and the second graft-engaging surface define a graft-accepting through-passage with a longitudinal axis extending therethrough when the first member is secured to the second member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The application is a continuation of U.S. patent application Ser. No. 11/717,792 filed on Mar. 13, 2007, the entire disclosure of which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to endoscopic soft tissue replacement fixation. More particularly, the present disclosure relates to an apparatus and a method to reconstruct an anterior cruciate ligament with soft tissue replacements within a femoral or tibial tunnel. 
       BACKGROUND 
       [0003]    The knee joint is frequently the object of injury and is often repaired using arthroscopic surgical procedures. An example of such arthroscopic surgical procedure is the replacement of anterior cruciate ligaments of the knee. The tearing of these ligaments is common in sports activities such as football or skiing. 
         [0004]    It has been difficult to insert and fasten a soft tissue replacement in a blind hole or tunnel. Attempts have been made to thread the soft tissue replacement through the tunnel and over an anchor, but with some difficulty. As such, improvements which provide a quick and efficient way to couple a soft tissue replacement to an implanted anchoring system are desirable. 
         [0005]    Currently, fascia lata soft tissue replacements are flexible strands which are affixed to a threaded stud and turned into the femoral tunnel. Unfortunately, this procedure may result in the soft tissue replacement being wrapped upon itself during insertion. Hamstring soft tissue replacements are also currently fixed over a screw in the tibial tunnel and fixed on the lateral femur. This technique may require the femoral tunnel to completely penetrate the femur. In addition, according to present procedures, fixation of the soft tissue replacement on the femoral side may require a large incision. 
         [0006]    Additional procedures include the use of bone-tendon-bone grafts which have been pre- or intra-operatively harvested from a donor site. In addition to the problems associated with graft retrieval, these bone-tendon-bone grafts are of fixed length. This fixed length significantly reduces their usability, as it is not possible to easily adjust the tension or length of the implanted tendon. 
         [0007]    While offering certain improvements in arthroscopic surgery to repair ligaments, the prior art may still be improved upon to overcome the limitations of the endoscopic hamstring soft tissue replacement fixation due, in many instances, to the weakness of the mechanism used to couple the tendon soft tissue replacement to an aperture formed within a bone. Other techniques attempt to use biological fixation to augment or replace mechanical fixation. While increasing fixation strength, these techniques require time to fully realize their fixation potential. Additionally the techniques may take additional surgical time and resources that a purely mechanical fixation technique may not require. 
       SUMMARY 
       [0008]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0009]    The present teachings provide for a device for surgically coupling a soft tissue graft into a tunnel of a bone. The device includes a first member and a second member. The first member includes a first graft-engaging surface extending from a first end to a second end of the first member. The second member includes a second graft-engaging surface extending from a first end to a second end of the second member. The first graft-engaging surface and the second graft-engaging surface define a graft-accepting through-passage with a longitudinal axis extending therethrough when the first member is secured to the second member. 
         [0010]    The present teachings further provide for a device for surgically coupling a soft tissue graft into a tunnel of a bone. The device includes a first member and a second member. The first member includes a convex first bone-engaging surface extending from a first end to a second end of the first member, a concave first graft-engaging surface extending from the first end to the second end of the first member that is opposite to the first bone-engaging surface, and a plurality of graft-engaging members included with the first graft-engaging surface. The second member includes a convex second bone-engaging surface extending from a first end to a second end of the second member and a concave second graft-engaging surface extending from the first end to the second end of the second member that is opposite to the second bone-engaging surface. The first graft-engaging surface and the second graft-engaging surface define a graft-accepting through-passage when the first member is coupled to the second member. The graft-accepting through-passage defines a generally circular cross-section taken along a first line perpendicular to a longitudinal axis extending through the graft-accepting through-passage. 
         [0011]    The present teachings also provide for a method for surgically coupling a soft tissue graft into a tunnel of a bone. The method includes positioning a first end of the soft tissue graft against a first graft-engaging surface of a first member, the first member including a first bone-engaging surface opposite to the first graft-engaging surface; coupling a second member to the first member to secure the first end of the soft tissue graft in a generally tubular graft-accepting passage defined by the first graft-engaging surface of the first member and a second graft-engaging surface of the second member, the coupled first member and the second member provide a first prosthetic assembly; forming the tunnel in the bone; determining an appropriate length of the soft tissue graft; inserting at least a portion of the first prosthetic assembly within the tunnel; and affixing the first prosthetic assembly in the tunnel and affixing a second end of the soft tissue graft with respect to the tunnel. 
         [0012]    Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIGS. 1 and 2  represent a method of forming a prosthetic about a graft according to one embodiment of the teachings herein; 
           [0014]      FIGS. 3   a - 3   c  represent prosthetics formed using the method shown in  FIGS. 1 and 2 ; 
           [0015]      FIG. 4  represents an alternate mold used to form the prosthetics shown in  FIGS. 3   a - 3   c;    
           [0016]      FIGS. 5   a - 5   d  represent optional tying mechanisms; 
           [0017]      FIGS. 6   a - 6   c  represent prosthetics utilizing the tying mechanisms shown in  FIGS. 5   a - 5   d;    
           [0018]      FIGS. 7   a  and  7   b  represent coupling an alternate prosthetic to a graft and to the insertion thereof; 
           [0019]      FIGS. 8   a  and  8   b  represent an alternate coupling prosthetic; 
           [0020]      FIGS. 9   a - 9   d  represent perspective and side views of an alternate embodiment; 
           [0021]      FIG. 10  represents fasteners used to couple the graft construction to a femoral tunnel; 
           [0022]      FIG. 11  represents an artificial bone-tendon-bone fastener graft construction; and 
           [0023]      FIG. 12  represents the construction according to  FIG. 9   c  coupled to a tibial and femoral tunnel using the fastener of  FIG. 10 . 
       
    
    
       [0024]    The descriptions of the teachings are merely exemplary in nature and, thus, variations that do not depart from the gist of the teachings are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the teachings. 
       DETAILED DESCRIPTION 
       [0025]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features. 
         [0026]      FIGS. 1 and 2  represent a system and method of forming a prosthetic  20  about a graft or graft replacement material  22  to form an artificial bone-tendon or bone-tendon-bone prosthetic assembly  24  according to one embodiment disclosed herein. Shown is a mold  23  having a first and second dies  26  and  28 , which define a cavity  30  therethrough. Defined by the first die  26  is an injection port  32 , which allows for the filling of the through cavity  30  with biocompatible material. As shown in  FIG. 1 , a suture  34  is threaded through a loop  36  of the replacement graft material  22 , or tied to the ends of the graft material  22 . 
         [0027]    The suture  34  and loop  36  of graft material  22  are pulled through the through cavity  30  to position the loop  36  of graft  22  in the cavity  30 . After the loop  36  of graft material  22  is placed within the through cavity  30 , an uncured biocompatible polymer material  31 , bone cement, or a calcium phosphate containing mixture is then injected through injection port  32 . After the curing or setting of the polymer  31 , the first and second dies  26  and  28  are separated exposing the prosthetic  20  intimately frictionally and/or mechanically coupled to the graft  22 . In this regard, the exterior surface of a portion of the replacement graft is completely enclosed or encapsulated by the prosthetic  20 . In other words, the prosthetic can function to protect this portion of the graft replacement  22  from interaction with hardware used to couple the graft assembly  24  to the bone. The replacement graft  22  may be a preoperative or intraoperatively harvested tendon such has a hamstring or may be xenograft, allograft, or artificial graft material. 
         [0028]    As shown in  FIGS. 3   a - 3   c , the exterior surface  38  of the prosthetic  20  can be textured by modifying the interior surface of the cavity  30 . In this regard, the exterior surface  38  can be smooth, porous, or define an external thread. As described below, the exterior surface  38  can also define locking features which interface with a fastener or an interior surface of an implant accepting bore to fix the prosthetic assembly  24  within an aperture. Additionally, the exterior surface  38  can be shaped or machined after molding. 
         [0029]      FIG. 4  represents an alternate mold  33  for forming the prosthetics shown in  FIGS. 3   a - 3   c . As shown, the cavity  30  can be defined by a single die  26 ′. This die  26 ′ defines a generally cylindrical cavity  30 , which has a conical injection port  32 . The suture  34  can be threaded through the injection port  32 , pulling the soft tissue replacement within the cavity  30 . After the biocompatible material is placed into the conical injection port  32 , a plunger-type cap  46  can be inserted into the conical injection port  32  to press the biocompatible material into the cylindrical cavity. It is envisioned that the injection port  32  can be threaded or configured to be formed to accept a syringe, which can be used to inject biological material or bone cement. The cavity  30  can be tapered to facilitate removal of the prosthetic assembly  24  after setting of the polymer  31 . Alternately, the interior surface of the molds  26  can have a plurality of members (not shown) which function to position the graft material  22  centrally within the mold  26 . Further, these members can compress the graft material  22  at discrete locations to allow the formation of a plug with interdigitation of cement. (see  FIG. 6   a ). 
         [0030]      FIGS. 5   a - 5   d  represent optional tying mechanisms  42   a - 42   d , which are used to bind the loop  36  of graft material  22 . As shown in  FIG. 6   b , a plurality of tying mechanisms  42   a - 42   d  can be annularly disposed about the loop  36  of the graft material  22 . The interior surface of the tying mechanisms  42   a - 42   d  can be textured  43  so as to prevent the relative displacement of the tying mechanism  42   a - 42   d  with respect to the loop  36  of the graft material  22 . As shown in  FIG. 5   c , the tying mechanism  42   a - 42   d  can have structures  45  that allow for the non-releasable or releasable tightening of the tying mechanism about the graft loop  36 . 
         [0031]    As shown in  FIG. 6   c , a single tying member  42   d  can be formed as a coil spring  42   d . The coil spring  42   d  can be radially expanded so as to allow for the insertion of the loop  36  into an inner space defined by the coils of the coil spring  42   d . After the tying mechanism is coupled to the graft loop  36 , the subassembly is positioned within the mold as disclosed above to form the prosthetic assembly  24 . Depicted is a cross-sectional view of the graft loop  36  disposed within the formed prosthetic  20 . Shown is the tying mechanism  42   d  disposed about the graft loop  36  which is fully disposed within the prosthetic  20 . While a distal end of the loop  36  of graft material is shown being exposed to allow acceptance of a suture, it is equally envisioned the distal end of the loop  36  can be fully incorporated into the prosthetic  20 . 
         [0032]      FIG. 7   a  represents an alternate prosthetic  50  configured to be coupled to the loop  36  of the graft material  22 . The prosthetic  50 , as well as those described below, are formed of first and second members  52  and  54  which are mechanically, ultrasonically, or adhesively coupled together. The members  52  and  54  together define a graft-accepting through-passage  56 . Disposed within the through-passage  56  are a plurality of counter-posed graft-engaging members  58 . The counter-posed graft-engaging members  58  are configured to pierce or frictionally engage the graft material  22 . Additionally, optional coupling surfaces can be formed on the counter-posed graft-engaging members  58  to couple the first and second members  52  and  54  together. 
         [0033]    As described above, optionally disposed on an exterior surface of the prosthetic  50  is a bone-engaging bearing surface  60 . This bone-engaging bearing surface  60  can be on either or both of the first and second members  52  and  54 .  FIG. 7   b  shows the prosthetic  50  disposed within a bore  64  defined in a tibia  66 . As shown, the bone-engaging bearing surface  60  has an angled bearing surface  62 , which interfaces with a counter sunk surface  65  formed in an outer surface of the tibia  66 . The prosthetic  50  is formed of a biocompatible material. In this regard, the material can be any biocompatible material such as metal or polymer such as ultrasonically bondable PEEK, PEKK, or can be a resorbable material such as Lactosorb®. 
         [0034]      FIGS. 8   a  and  8   b  represent perspective views of an alternate prosthetic  68  according to the disclosure herein. The prosthetic  68  is formed of first and second members  70  and  72 . The first member  70  is generally cylindrical having a graft loop accepting through-passage  74 . The first member  70  can be formed of an inner member  77  and an outer member  78 . The inner member  76  defines a plurality of graft-engaging member accepting apertures  77 . These apertures  77  can be formed on opposite sides of the first member  70  to facilitate the locking of the graft-engaging second member  72  to the first member  70 . The outer member  78  is annularly disposed about the inner member  76 . In this regard, the outer member  78  defines a groove  80 , which generally surrounds the graft-engaging member apertures  76 . The second member  72  is generally arcuate and is configured to be disposed within the groove  80  formed by the outer member  78 . Disposed on a convex inner surface  82  of the second member  72  are a plurality of graft-engaging members  79 . These graft-engaging members  79  are configured to be aligned with the graft-engaging member apertures  77  formed in the first member  70 . 
         [0035]    As shown in  FIG. 8   b , the graft loop  36  is fed through the loop-accepting aperture  81 . The graft-engaging members  79  are aligned with the apertures  77 . The second member  72  is displaced toward the first member  70 , causing the graft-engaging member  79  to pierce or frictionally engage the graft loop  36 . The first and second members  70  and  72  are then ultrasonically, adhesively, press-fit or heat bonded together to form a single prosthetic. 
         [0036]    As shown in  FIGS. 9   a - 9   d , the prosthetic  50  can have a plurality of coupling flanges  84 , which can be disposed about a mating surface  86 . These flanges  84  are configured to interface with corresponding slots  88  in the first member. As described above, the exterior surface  90  of the implant  50  can be textured. As shown, the exterior surface  90  can define an angled threaded depression  92 , which is configured to accept a bone-engaging screw  100  (see  FIG. 10 ). Additionally the exterior surface can define a generally concave threaded depression  93  which runs the length of the length of the implant. 
         [0037]      FIG. 11  represents an artificial bone-tendon-bone prosthetic assembly  24 . The assembly  24  includes a pair of prosthetics  20  as shown in  FIG. 9   d  coupled to proximal and distal ends of a loop of graft material. It is envisioned that the prosthetics  20  used to form the artificial bone-tendon-bone prosthetic assembly  24  can utilize any of the aforementioned prosthetics  20 . Additionally shown is the suture used to install the artificial bone-tendon-bone prosthetic assembly  24  into the bone. 
         [0038]      FIG. 12  depicts an implant  50  coupled to a graft  22  disposed within a tibial and femoral tunnel. As mentioned above, the graft  22  is coupled to the prosthetic  20  to form an artificial bone-tendon or bone-tendon-bone prosthetic assembly  24 . It is envisioned the physician can intraoperatively determine the desired graft or graft assembly length and appropriate graft tension. The first prosthetic  20  is coupled to a first end of the replacement graft either preoperatively or intraoperatively using any of the methods described above. The physician then determines an appropriate length for the graft material  22  by measuring an anatomical distance. 
         [0039]    An appropriate amount of tension is applied to the graft and the length of the graft is then marked. A second prosthetic  20 ′ is then coupled to the prosthetic assembly at the marked location. This location is a function of the measured anatomical distance, which takes into account mounting structures. This provides an appropriately sized artificial bone-tendon-bone prosthetic. It is envisioned the second prosthetic  20  would then be coupled to the graft material intraoperatively. Optionally, a kit of preformed artificial bone-tendon graft assemblies with an associated second prosthetic can be provided. Additionally, the kit can contain the molds  26  or  26 ′ shown in  FIG. 1  or  4 , and a package of premeasured castable material. 
         [0040]    Once the graft assembly  24  is formed, a suture  34  is coupled to the assembly. The suture  34  and prosthetic assembly  24  are threaded into the tunnel formed in the bone or bones, so as to position the prosthetics  20  and  20 ′ near an opening of the tibial and femoral tunnel. A fastener  100  is engagably driven between the implants  50  and the internal surface  94  of the bore  96  formed in the tibia. This locks the graft assembly  24  to the bone. Appropriate tension is applied to the graft, which is fixed at its second end by a soft tissue/bone-engaging fastener  100  or other suitable means. 
         [0041]    The description of the teachings is merely exemplary in nature and, thus, variations that do not depart from the gist of the teachings are intended to be within the scope of the teachings. Such variations are not to be regarded as a departure from the spirit and scope of the teachings.