Abstract:
A method for performing an anterior cruciate ligament repair procedure wherein a bone plug attached to a section of tendon or ligament is fixed in a bone tunnel. The method utilizes an adhesive to secure the bone block in the bone tunnel.

Description:
FIELD OF THE INVENTION  
         [0001]    The field of art to which this invention relates is orthopedic surgical methods, in particular, surgical procedures for fixating bone grafts in bone tunnels.  
         BACKGROUND OF THE INVENTION  
         [0002]    Joint injuries may commonly result in the complete or partial detachment of ligaments, tendons and soft tissues from bone. Tissue detachment may occur in may ways, e.g., as the result of an accident such as a fall, overexertion during a work-related activity, during the course of an athletic event, or in any one of many other situations and/or activities. These types of injuries are generally the result of excess stress or extraordinary forces being placed upon the tissues.  
           [0003]    In the case of a partial detachment, commonly referred to under the general term “sprain”, the injury frequently heals without medical intervention, the patent rests, and care is taken not to expose the injury to undue strenuous activities during the healing process. If, however, the ligament or tendon is completely detached from its attachment site on an associated bone or bones, or if it is severed as the result of a traumatic injury, surgical intervention may be necessary to restore full function to the injured joint. A number of conventional surgical procedures exist for re-attaching such tendons and ligaments to bone.  
           [0004]    One such procedure involves the re-attachment of the detached tissue using “traditional” attachment devices such as staples, sutures, and bone screws. Such traditional attachment devices have also been used to attach tendon or ligament grafts (often formed from autogenous tissue harvested from elsewhere in the body) to the desired bone or bones.  
           [0005]    In U.S. Pat. No. 4,950,270, a surgical procedure is disclosed to replace a damaged anterior cruciate ligament (“ACL”) in a human knee. Initially bone tunnels are formed through the tibia and femur at the points of normal attachment of the anterior cruciate ligament. Next, a ligament graft with a bone block on one of its ends is sized so as to fit within the bone tunnels. Suture is then attached to the bone block and thereafter passed through the tibia and femoral bone tunnels. The bone block is then pulled through the tibia tunnel and up into the femoral tunnel using the suture. As this is done, the graft ligament extends back out of the femoral tunnel, across the interior of the knee joint, and then through the tibial tunnel. The free end of the graft ligament resides outside the tibia, at the anterior side of the tibia. Next, a bone screw is inserted between the bone block and the wall of femoral bone tunnel so as to securely lock the bone block in position by a tight interference fit. Finally, the free end of the graft ligament is securely attached to the tibia.  
           [0006]    In U.S. Pat. No. 5,147,362, another ACL reconstruction procedure is disclosed. Aligned femoral and tibia tunnels are initially formed in a human knee. A bone block with a graft ligament attached thereto is passed through the tunnels to a blind end of the femoral tunnel where the block is fixed in place by an anchor. The ligament extends out of the tibia tunnel, and the end is attached to the tibia cortex by staples or the like. Alternatively, the end of the ligament may be fixed in the tibia tunnel by an anchor or by an interference screw.  
           [0007]    Various types of ligament and/or suture anchors for attaching soft tissue to bone are also well known in the art. A number of these devices are described in detail in U.S. Pat. Nos. 4,898,156; 4,899,743; 4,968,315; 5,356,413; and 5,372,599, which are incorporated by reference in their entirety.  
           [0008]    One known method for anchoring bone blocks in bone tunnels is through “cross-pinning” technique, in which a pin, screw or rod is driven into the bone transversely to the bone tunnel so as to intersect the bone block and thereby cross-pin the bone block in the bone tunnel. In order to provide for proper cross-pinning of the bone block in the bone tunnel, a drill guide is generally used. The drill guide serves to ensure that the transverse passage is positioned in the bone so that it will intersect the appropriate tunnel section and the bone block.  
           [0009]    U.S. Pat. No. 5,431,651, discloses a cross-pin screw made from a broadabsorbable material which is absorbed by the body over time, thereby eliminating any need for the cross-pin screw to be removed in a subsequent surgical procedure.  
           [0010]    Although the soft tissue attachment procedures of the prior art have proven to be beneficial, there is a continuing need in this art for novel, improved surgical procedures, particularly in the area of anterior cruciate ligament reconstruction.  
         SUMMARY OF THE INVENTION  
         [0011]    Accordingly it is an object of the present invention, to provide a method for fixing a bone block in a bone tunnel such that the bone block is retained in the tunnel by a bone cement or bone glue, thereby eliminating the need for a cross-pin or screw or other mechanical fastening device to secure the bone block.  
           [0012]    It is a further object of the present invention to provide a novel method of graft fixation in an anterior cruciate ligament reconstruction procedure using a bone cement or bone glue.  
           [0013]    Therefore, a novel method of performing a surgical reconstruction of an anterior cruciate ligament is disclosed. The method consists of providing a bone-tendon graft comprising at least one bone plug connected to a section of tendon. The bone plug has an outer surface. Next, a substantially longitudinal bone tunnel is drilled into a patient&#39;s tibia, and a substantially longitudinal bone tunnel is drilled into the patient&#39;s femur. The femoral bone tunnel and the tibial bone tunnel are drilled so as to be in substantial alignment. Each bone tunnel has an inner surface. The bone plug is then inserted into the femoral tunnel such that the tendon extends from the femoral plug, out of the femoral bone tunnel, and into the tibial bone tunnel. And, a bone glue or cement is introduced into the femoral tunnel such that the glue or cement is in at least partial contact with the outer surface of the bone plug and the inner surface of the femoral bone tunnel, thereby securing the bone plug in the femoral tunnel.  
           [0014]    Yet another aspect of the present invention is the above-described method wherein the bone glue or cement is inserted into the femoral bone tunnel prior to inserting the bone plug.  
           [0015]    Still yet another aspect of the present invention is a method of securing a bone plug in a bone tunnel. A bone tunnel is drilled into a bone. A bone plug is provided. A glue or cement is introduced into the bone tunnel to secure the bone plug in the bone tunnel.  
           [0016]    These and other advantages of the present invention will become more apparent from the following description and accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0017]    [0017]FIG. 1 illustrates a human knee prior to harvesting a bone-tendon-bone graft; the outline of the graft on the patella, patellar tendon, and tibia is shown by phantom lines.  
         [0018]    [0018]FIG. 2 illustrates a bone-tendon-bone graft after harvesting; the bone plug that is inserted into the femur has a suture mounted thereto.  
         [0019]    [0019]FIG. 3A illustrates a knee after a pilot drill was used to drill a series of pilot holes into the tibia and femur of a knee joint, including the suture tunnel, and after a conventional concentric bone drill was placed over the pilot drill to drill out the tibial and femoral bone tunnels; the pilot drill is shown in place in the knee, the concentric drill is not shown.  
         [0020]    [0020]FIG. 3B illustrates the knee joint of FIG. 3A after the tibial and femoral bone tunnels have been drilled out, and illustrates a drill guide being mounted to the knee; also illustrated is a cannula and a trocar drill used for drilling a transverse glue tunnel.  
         [0021]    [0021]FIG. 3C illustrates a transverse glue tunnel being drilled into the femur in communication with the femoral bone tunnel.  
         [0022]    [0022]FIG. 3D illustrates the knee after the transverse glue tunnel has been drilled and the drill has been removed.  
         [0023]    [0023]FIG. 3E illustrates a removable clamp on the drill guide which is disengaged prior to removing the drill guide from the knee in order to allow the cannula to remain in place in the glue tunnel.  
         [0024]    [0024]FIG. 4 illustrates the knee with the drill guide removed, and also illustrates a trocar cannula inserted into the glue tunnel; the distal tip of the cannula extends into the femoral bone tunnel.  
         [0025]    [0025]FIG. 5 illustrates the graft being emplaced in the femoral and tibial tunnels by pulling on the suture attached to the femoral bone plug.  
         [0026]    [0026]FIG. 6 illustrates the tibial and femoral bone plugs in place in the bone tunnel; and, bone glue being introduced into the cannula in the femoral bone tunnel through the transverse glue hole to secure the femoral bone plug by using a hypodermic needle to inject the glue into the cannula.  
         [0027]    [0027]FIG. 7 illustrates a bolus of glue in the femoral tunnel between the top of the femoral plug and the distal end of the femoral tunnel injected via the needle of the syringe placed in the cannula.  
         [0028]    [0028]FIG. 8 illustrates a bolus of glue on top of the femoral plug in the femoral bone tunnel prior to setting the femoral plug in place; the cannula has been removed.  
         [0029]    [0029]FIG. 9 is a partial cross-sectional view illustrating the graft after the femoral plug has been pulled into place, and the glue has been spread about the femoral plug and femoral tunnel.  
         [0030]    [0030]FIG. 10 illustrates an alternate embodiment of the present invention, wherein the adhesive is introduced into the femoral bone tunnel through the distal suture hole in the femur in communication with the femoral bone tunnel, to secure the femoral bone plug.  
         [0031]    FIGS.  11 A-B illustrate another embodiment of the present invention wherein the bone glue is contained in a frangible capsule which is introduced in the femoral bone hole prior to emplacing the femoral bone plug, and the capsule is crushed when the femoral plug is pulled into place, thereby allowing the glue to exit the capsule and make contact with the bone plug and the interior surface of the femoral bone tunnel. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]    The terms “bone cement” and “bone glue” are used interchangeably herein when describing the surgical procedures of the present invention. The term “tendon” as used herein is defined to include both tendons and ligaments. The bone-tendon-bone ACL reconstruction surgical procedures of the present invention are initiated by first providing a bone-tendon-bone graft. Also, depending upon the particular circumstances surrounding an individual patient and the particular injury, a bone-tendon graft could also be used having a single bone plug. As seen in FIG. 1, knee joint  10  consisting of a tibia  20 , femur  40 , and a patella  60  having patella tendon  80  is illustrated. An autologous bone-tendon-bone graft  100  useful in the procedure of the present invention is illustrated in FIGS. 1 and 2. The graft  100  is harvested in a conventional manner. The graft  100  is seen to have tendon section  110  having proximal end  112  and distal end  114 . The femoral bone plug  120  is seen to be cut out from the patella  60 . The bone plug  120  is seen to have outer surface  125 , proximal end  130  connected to the distal end  114  of tendon section  110  and distal end  135 . The tibia bone plug  140  is seen to be cut from tibia  20 , and is seen to have distal end  145  connected to the proximal end  112  of tendon  110 . The bone plug  140  is also seen to have outer surface  150  and distal end  155 . Suture  160  is seen to be inserted through tunnel  165 .  
         [0033]    After the bone-tendon-bone graft  100  has been harvested, as seen in FIG. 2, it is maintained in a moist condition prior to implantation in a conventional manner. Next, the patient&#39;s knee is prepared to receive the graft  100  by drilling tunnels into the femur and tibia as seen in FIG. 3A. A substantially longitudinal bone tunnel  200  is drilled into the tibia  20  in a conventional manner using conventional surgical equipment. The bone tunnel  200  is seen to have longitudinal passage  205  and longitudinal axis  206 . Bone tunnel  200  is additionally seen to have first opening  210  and second opening  220 , both openings which are in communication with passage  205 . In addition, tibial bone tunnel  200  is seen to have interior surface  225 . The femoral bone tunnel  250  is also drilled into the femur using conventional surgical equipment and techniques. The femoral tunnel  250  is seen to have opening  260 , longitudinal passage  255  and longitudinal axis  256 . The femoral bone tunnel  250  is also seen to have distal end  270  and inner surface  265 . Longitudinal axis  256  is seen to be in substantial alignment with longitudinal axis  206 . Next, the suture tunnel  280  is drilled into the femur such that the suture tunnel  280  is substantially in longitudinal alignment with the longitudinal axis  256  of the femoral bore hole  250 . Suture tunnel  280  is seen to have interior passage  286 . In addition, tunnel  280  is seen to have first opening  282  and second opening  284  such that the inner passage of tunnel  280  is in communication with the inner passage  255  of femoral bore hole  250  through opening  282  and also in communication with the exterior of the femur  40  through opening  284 . The glue tunnel  300  is seen to be substantially transverse to longitudinal axis  256  of femoral tunnel  250  in a preferred embodiment, but may, if desired, be angulated. Glue tunnel  300  is seen to have interior passage  305  in communication with passage  255  through first opening  307 , and in communication with the exterior of femur  40  through second opening  308 .  
         [0034]    The tunnels  200 ,  250 , and  280  are drilled in a conventional manner using conventional surgical orthopedic drilling equipment. Initially, the surgeon aligns the tibia and femur into the desired position for the procedure. Next, the distal end  355  of pilot pin drill  350  is placed against the outer surface of the tibia and a pilot bone hole is drilled through the tibia and femur by rotating drill  350  with a conventional surgical drill apparatus, until the end  355  exits the femur from opening  284  thus creating tunnel  280 , and the pilot bone hole precursors for tunnels  200  and  250 . Tunnels  200  and  250  are further formed by drilling with a conventional concentric surgical drill  370  (not shown) having drilling end  375  and inner passage  372 , which is mounted over pilot pin drill  350  in a conventional manner. After the drilling of tunnels  200 ,  250  and  280  has been successfully completed, the pilot pin drill  350  and concentric drill  370  are withdrawn from the tunnels.  
         [0035]    Next, the transverse glue tunnel  300  is drilled into the femur. Specifically, as seen in FIGS.  3 B-E, the conventional L-shaped drill guide  400  is used to locate and align the transverse tunnel  300 . Drill guide  400  is seen to have first and second legs  410  and  430 . At the end  412  of leg  410  is located the base receiver  415 . Extending up from base receiver  415  is the locating leg  420  having proximal end  422 , and distal end  424 . If desired, although optional, drills and other instruments can be inserted through base receiver  415  into and through locating leg  420  by providing appropriate openings and passageways. Leg  430  is seen to have end  432  and drill receiver  435  mounted thereto, having first opening  436 , second opening  437  and internal passageway  439  in communication with both openings. Locating leg  420  is seen to be mounted in tibial bone hole  200 .  
         [0036]    Then, cannula  450  having drill  390  with distal drilling end  395  located therein, is inserted into and through opening  432  of drill guide  400 , and the drill  390  is rotated by a conventional surgical drill to drill out glue tunnel  300  and place cannula  450  in tunnel  280 . Cannula  450  is seen to have internal passage  452 , proximal end opening  454  in communication with passage  452  and distal end opening  456  in communication with passage  452 . After the tunnel  300  is completely formed, drill  390  is removed and guide  400  is removed by removing retention bracket  490  secured by screw  492  and pulling out leg  420  from passage  200 , leaving cannula  450  in glue tunnel  280 . Although not preferred, the method of the present invention can be performed without the use of cannula  450 . Also, if desired, cannula  450  may be placed into the tunnel  280  subsequent to drilling.  
         [0037]    Referring now to FIGS.  4 - 9 , after the bone tunnels  200  and  250 , the suture tunnel  280 , and glue tunnel  300  have been drilled, the longitudinal axes  206  and  256 , respectively, of the bone tunnel  200  and bone tunnel  250  are placed in alignment by the surgeon. Next, the conventional suture  160  mounted to the femoral bone plug  120  is threaded through the interior passages of  205  and  255  of the tibial tunnel  200  and the femoral tunnel  250 , respectively, and is further threaded through and out of the suture tunnel  280 . Next, the surgeon pulls the suture  160  such that the femoral plug passes into passage  255  of the femoral tunnel  250  and the tibia plug passes into passage  205  of the tibia tunnel  200 .  
         [0038]    The surgeon is careful to locate the distal end  135  of the femoral bone plug  120  immediately below the opening  307 . At this time, the tibial bone plug  150  is either partially or completely located in bone tunnel  200 . Next, the surgeon injects a bone glue or bone cement into the cannula  450  using a conventional syringe  500  such that a bolus of the bone cement or bone glue  550  flows through the interior passage of cannula  450 , through the interior of glue tunnel  300 , and finally into the interior of bone tunnel  250  as seen in FIGS. 6, 7 and  8 . Syringe  500  is seen to have barrel  510  for receiving glue  550  plunger  520  and hollow needle  530 . The surgeon then removes the trocar  450  and syringe  500  from the glue tunnel  300 , next the surgeon pulls on the ends of suture  160  thereby pulling the bone plug  120  into position in the femoral bone tunnel  250  such that the distal end  135  or the bone plug  125  abuts the distal end  270  of the bone tunnel  250 . At the same time the glue  550  is spread in and about the inner surface  265  of the bone tunnel  250  and the outer surface  125  of the plug  120  thereby securing the bone plug in place upon the curing of bone glue or bone cement  550 . The suture  160  may then be removed from the femoral bone plug  120 , or the ends external to the femur may be cut. The tibial bone plug  140  can then be secured in the bone tunnel  200  in a conventional manner using, for example, bone screws or pins. Or, if desired, an additional transverse glue hole can also be drilled into the tibia in communication with tibial tunnel  200 , and bone glue or bone cement  550  may be similarly delivered by the surgeon into the bone tunnel  200  through the tibial glue tunnel. Although not preferred, the surgeon may inject a bolus of bone glue  550  into femoral bone tunnel  250  prior to locating the femoral bone plug  120  in tunnel  250 .  
         [0039]    [0039]FIG. 10 illustrates and alternate embodiment of an ACL reconstruction method of the present invention. As seen in FIG. 10, the method steps are similar to that of the previously described preferred method, except that the glue tunnel  300  is not drilled and utilized. Instead, the glue  550  is injected via syringe  500  through the suture tunnel  280  into the femoral bone tunnel  250  when the bone plug  120  is partially engaged in the bone tunnel  250 , or prior to inserting the bone plug  120  into femoral bone tunnel  250 .  
         [0040]    Yet another embodiment of the ACL reconstruction method of the present invention is illustrated in FIGS.  11 A-B. In FIGS.  11 A-B, the method steps are similar to that of the method steps of the preferred embodiment of the present invention. However, rather than drilling a transverse bone tunnel or injecting bone glue or cement through the suture tunnel, a frangible capsule  600  containing bone glue or bone cement  550  is inserted into the femoral tunnel  250  prior to introducing the plug  120  into the tunnel  250 . Then the surgeon pulls the suture threads  60  upwardly such that the distal end of the bone plug engages the frangible capsule  600  thereby breaking open the shell  610  of capsule  600  and causing glue  550  contained in the interior  620  of capsule  600  to be spread about the inner surface  265  of the bone tunnel  250  and the outer surface  125  of the plug  120 .  
         [0041]    The methods of the present invention preferably will utilize bone plugs and tendons and ligaments harvested from autologous tissue in the patient&#39;s knee or other areas of the body as illustrated in FIGS. 1 and 2 using conventional surgical techniques. However, if desired, artificial bone plugs and tendons may be utilized. The bone plugs may consist of conventional bone substitute materials including polylactic acid and polyglycolic acid as well as bioceramics such as tricalcium phosphate, calcium phosphate, tetracalcium phosphate and hydroxyapatite, and any copolymers, mixtures or blends thereof, and the like and equivalents thereof. The artificial tendons or ligaments can consist of conventional tendon replacement materials including carbon fibers, polyethylene terephthalate, polytetrafluoroethylene (PTFE), polypropylene, as well as biodegradable polymers including polylactic acid, polyglycolic acid, polydioxanone, polycarbonate, polycaprolactone, and copolymers thereof, and the like, and combinations thereof and equivalents thereof.  
         [0042]    The amount of glue or cement used to secure the bone plugs in the bone tunnels in the method of the present invention will be sufficient to effectively maintain the bone plugs in place after curing and setting. The amount that is used will depend upon several factors including the characteristics and nature of the bone plug, the nature and characteristics of the bone cement or glue, the size and length of the bone tunnels, the nature and characteristics of the bone glue or cement and the individual characteristics of the patient.  
         [0043]    The term “adhesive” is used collectively herein to include bone glues and bone cements. The bone glues which can be used in the practice of the present invention include conventional biocompatible bone glues including 2-octyl cyanoacrylate and the like and equivalent thereof. The bone cements which can be used in the practice of the present invention include conventional biocompatible bone cements such as polymethylmethacrylate and the like. The bone glues and bone cements may be absorbable or nonabsorbable.  
         [0044]    The frangible capsules  600  useful in the practice of the embodiment of the method of the present invention will typically have a hollow body having a shell  610  and interior  620 . The interior  620  of the shell  610  will be filled with bone cement or bone glue  550 . The shell will typically be made out of biocompatible material which is frangible and will break or rupture when squeezed or compressed. Examples of such shell materials include gelatin, and conventional bioabsorbable and bioresorbable polymeric materials, and the like.  
         [0045]    The following example is representative of the principles and practice of the present invention although not limited thereto.  
       EXAMPLE  
       [0046]    A patient was anesthetized in accordance with conventional anesthesiology procedures. The patient&#39;s knee joint was prepared for an ACL reconstruction in a conventional manner. Incisions were made into the knee exposing the lower part of the femur, the upper part of the tibia, the tibial tendon and the patellar tendon. A bone-plug-tendon-bone-plug bone graft was harvested from the patellar bone, the tibial tendon and the tibia. Then, a conventional pilot pin wire drill was utilized to drill a bone tunnel through the tibia into and out of the femur thereby creating the suture tunnel and precursor tibial and femoral bone tunnels. Next, a conventional concentric drill was placed over the drill/guide wire and the drill was operated in a conventional manner to create the tibial tunnel and the femoral bone tunnel. The drills were then removed. Then, a conventional drill guide was mounted on the patient&#39;s tibia and femur. Next, a transverse glue tunnel was drilled into the femur utilizing the drill guide and a conventional trocar drill and cannula, the tunnel intersecting the femoral bone tunnel such that the interior passage of the femoral bone tunnel was in communication with the transverse glue tunnel. After removing the drill, the cannula was left in place in the glue tunnel. Next, the surgeon prepared the bone tendon, bone graft by drilling a transverse hole through the femoral plug and inserting a length of conventional Ethibond® surgical suture therethrough. Next, the surgical suture was threaded through the tibial tunnel, the femoral tunnel and through and out of the suture tunnel so that both ends of the suture were exterior to the femur. Next, the surgeon proceeded to pull the bone-tendon-bone graft through the tibial tunnel and further into the femoral tunnel such that the distal end face of the femoral bone plug was located just proximal to the opening into the glue tunnel. Next, the surgeon mounted a the needle of conventional syringe containing about 40 cc of 2-octyl cyanoacrylate bone glue into the trocar cannula, and a bolus of the bone cement was injected through the cannula into the femoral bone tunnel, and the cannula was removed. Next, the surgeon continued to pull on the ends of the suture such that the distal face of the bone plug was in contact with the distal end of the femoral tunnel, effectively spreading the bolus of bone glue about the interior surfaces of the femoral bone tunnel and also over the exterior surfaces of the femoral bone plug such that the bone plug was effectively bonded to the interior surfaces of the bone tunnel by the bone glue. After waiting a sufficient period of time for the bone glue to cure, the surgeon cut off the ends of the suture, and the incisions were then approximated in a conventional manner utilizing conventional surgical sutures. Next, the surgeon secured the tibial plug to the tibial bone hole in a conventional manner utilizing a conventional bone screw. The patient&#39;s knee was then immobilized, and the ACL reconstruction was completed.  
         [0047]    The advantages of the improved ACL reconstruction methods of the present invention are numerous. It is now possible to perform an ACL reconstruction without having to use mechanical fasteners to maintain a femoral bone plug in place. In addition, the length of the surgical procedure can be reduced since it not necessary to drill additional bone tunnels to receive mechanical fasteners such as screws and pins.  
         [0048]    Although this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the claimed invention.