SINGLE TUNNEL DOUBLE BUNDLE POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Abstract

The present invention provides a method of performing posterior cruciate ligament replacement. Specifically, a graft tissue is harvested from a patient and single tunnels are prepared in each of the tibia and the femur of the patient. The graft is secured in the femoral tunnel and separated into a posterior cruciate medial bundle and a posterior lateral bundle. The bundles are inserted through the tibial tunnel. During insertion the posterior lateral bundle is positioned in a posterior lateral position in the tibial tunnel while the posterior cruciate medial bundle is positioned in a posterior cruciate medial position in the tibial tunnel. The posterior cruciate medial bundle is then tensioned while the patient's knee is in approximately 90 degrees of flexion, and the posterior lateral bundle is tensioned while the patient's knee is approximately in full extension. Each of the bundles is then secured in the tibial tunnel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 61/090,129, which is herein incorporated in its entirety, and is related to U.S. Provisional Patent Application Ser. No. 61/097,460, which is U.S. patent application Ser. No. ______.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention provides a method for posterior cruciate ligament reconstruction and, more particularly, a method for single tunnel double bundle posterior cruciate ligament reconstruction.

2. Related Art

Single tunnel single bundle posterior cruciate ligament reconstruction (STSBPCLR) has long been established as a method of posterior cruciate ligament (PCL) reconstruction. A variety of graft choices are available to surgeons during PCL reconstruction. These choices include autogenous patellar or quadriceps tendon with bone blocks, or hamstring tendons. In addition, patellar tendon or achilles tendon allografts (from donors) may be used. The main portion of the PCL which needs to be reconstructed is the anterolateral bundles. Arthroscopic assisted or open PCL reconstructions involve removing the remaining native PCL and drilling a tunnel at the anatomic attachment site of the anterolateral bundle at the anteromedial wall of the itercondylar notch. This tunnel is drilled in line with the roof of the notch and about 6-8 mm from the articular surface of the lateral femoral condyle. The tibial attachment site is then prepared by identifying the normal attachment site of the PCL at the bottom of the PCL facet. A tibial tunnel is drilled, at approximately a 75° angle and about 6 cm from the joint line, from posterior to posterior. Once the tunnels are drilled, sharp edges and soft tissues around the tunnel exit site are smoothed off with the use of a rasp. The graft is then passed into the joint and fixed in its femoral tunnel (usually with an interference screw). The graft is then tensioned distally while the knee is cycled several times to remove any slack in the graft. The graft is fixed to the tibia, usually with staples, while the knee is flexed to 90°, distal traction is placed on the graft, and a posterior force is applied to the tibia. After fixation, the posterior cruciate drawer is assessed to verify a return of normal posterior stability to the knee, and the surgical incisions are closed.

Double bundle double tunnel posterior cruciate ligament reconstruction (DBDTPCLR) has recently been described as a technique for PCL reconstruction which provides two bundles of tissue in separate tunnels. Recent biomechanical studies have shown that an anatomic double-bundle PCL reconstruction is superior in restoring normal knee laxity compared with the conventional single-bundle isometric reconstruction. One technique uses a double-bundle Y-shaped hamstring tendon graft. A double- or triple-bundle semitendinosus-gracilis tendon graft is utilized and directly fixed with interference screws. In the lateral femoral condyle, two femoral tunnels are created inside-out through a low anterolateral arthroscopic portal. First, in full extension, the double-stranded gracilis graft is fixed with an interference screw inside the lower femoral socket, representing the insertion site of the posteromedial bundle. In 80 degrees of flexion the combined semitendinosus-gracilis graft is pretensioned and fixed inside the posterior aspect of the single tibial tunnel. The double- or triple-stranded semitendinosus tendon is inserted in the higher femoral tunnel, presenting the insertion site of the anterolateral bundle. Finally, pretension is applied to the semitendinosus bundle in full extension and another screw is inserted. Using this technique, the stronger semitendinosus part of the double-bundle graft, which mimics the anterolateral bundle of the PCL, is fixed in full extension, whereas the smaller gracilis tendon part (posteromedial bundle) is fixed in flexion.

Kinematically the double bundle posterior cruciate ligament reconstruction has shown itself to be more closely related to the actual normal motion of the knee when compared to single bundle posterior cruciate ligament reconstructions. DBDTPCLR is technically demanding procedure requiring an extremely high level of surgeon skill. In addition DBDTPCLR requires four separate fixation devices to secure the soft tissue bundles in place to recreate a torn posterior cruciate ligament. Each bundle of tissue is separately tensioned in the respective tunnel prior to fixation with orthopedic devices.

SUMMARY OF THE INVENTION

The present invention provides a novel technique in which a double bundle PCL reconstruction is performed through a single tunnel and the separate bundles are independently tensioned. Accordingly, a new type of PCL reconstruction the Single Tunnel Double Bundle Posterior Cruciate Ligament Reconstruction (STBDPCLR) is created.

STDBPCLR utilizes a standard graft harvest and can be performed using either allograft or autograft tissues such as bone patellar tendon bone, wherein the graft includes a portion of the patella tendon having a bone plug on each end, or semitendinosus gracilis (hamstring) tendons. Standard tibial and femoral tunnels are prepared using either a trans-tibial or a trans-portal technique. The femoral graft fixation is important because the bundles for the PCL must be oriented in a proper direction to provide separate kinematic bundles created a through a single tunnel. The graft position on the femoral side is held in place through screws and/or other fixation devices used where the graft is prepared and separated into two separate bundles through implant design or through surgeon preparation. When using hamstring grafts, the grafts are positioned on the femoral side to provide for a posterior cruciate bundle that can be independently tensioned after femoral tunnel fixation. When using bone patellar tendon bone grafts, the femoral bone plug is left as one piece when inserted and the graft is prepared to provide for the separate bundles in the tibia.

During graft introduction into the knee two kinematically separate bundles are created. As the graft is pulled into the knee, the surgeon, who has marked the appropriate bundle of tissue which is to be the posterior cruciate lateral bundle, rotates this bundle to the posterior cruciate lateral position in the tibia while rotating the other bundle, the posterior cruciate medial bundle, to the posterior cruciate medial portion of the tibial tunnel, thereby creating the soft tissue required for both the posterior cruciate lateral and posterior cruciate medial bundles. With the separate bundle created in the knee and appropriately oriented, the bundles are tensioned independently. The posterior cruciate medial bundle is tensioned with the knee in 90 degrees of flexion while the posterior cruciate lateral bundle is tensioned with the knee in full extension. An external tensioning device is capable of cycling the separate bundles under tension or this can be accomplished with two separate screws inserted as posts into the tibia. Once the graft is tensioned, tibial fixation is either completed with the screws alone or, using a removable tensioning device, the bundles are secured in the tibial tunnel with a screw type fixation device and the external tensioner is removed. By anatomically creating two separate bundles and kinematically tensioning those separate bundles and fixating them, the surgeon creates a single tunnel double bundle posterior cruciate ligament repair (STDBPCLR).

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a view of a graft inserted into the femur of a knee.

FIG. 2 is a view of the graft shown in FIG. 1 separated into two bundles.

FIG. 3 is a view of the two bundles shown in FIG. 2 inserted through the tibia of the knee.

FIG. 4 is a view of the two bundles shown in FIG. 3 arranged as a posterior cruciate lateral bundle and posterior cruciate medial bundle.

FIG. 5 is a view of the knee in extension to provide tension to the posterior cruciate lateral bundle shown in FIG. 4 using a tensioning device.

FIG. 6 is a view of the knee in flexion to provide tension to the posterior cruciate medial bundle shown in FIG. 4 using the tensioning device shown in FIG. 5.

FIG. 7 is a view of the posterior cruciate lateral bundle and posterior cruciate medial bundle shown in FIG. 4 secured to the tibia shown in FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

FIGS. 1-7 illustrate a method of reconstructing the posterior cruciate ligament (PCL) of the knee 11 using a single tunnel double bundle technique. Prior to the reconstruction a standard graft harvest is performed using either allograft or autograft tissues such as bone patellar tendon bone or semitendinosus gracilis (hamstring) tendons. Standard tibial and femoral tunnels then are prepared using either a trans-tibial or a trans-portal technique.

As shown in FIG. 1, the graft 10 is fixed in the femur 12 using standard fixation techniques. For example, in the exemplary embodiment, when using hamstring grafts, the graft 10 is positioned on the femoral side 14 to provide for a posterior cruciate bundle that can be independently tensioned after femoral tunnel fixation. Alternatively, when using bone patellar tendon bone grafts, the femoral bone plug is left as one piece when inserted and the graft is prepared to provide for the separate bundles in the tibia. The graft is fixed in the femoral tunnel 16 so that the bundles for the PCL are oriented in a proper direction to provide separate kinematic bundles created through a single tunnel. In the exemplary embodiment, the graft 10 is held in place on the femoral side 14 using screws and/or other fixation devices 17 used when the graft is prepared and separated into two separate bundles through implant design or through surgeon preparation.

As shown in FIG. 2, the graft 10 is separated into two kinematically separate bundles 18 after the graft 10 is introduced into the femur 12. Each bundle 18 is marked as either the posterior cruciate lateral bundle 20 or the posterior cruciate medial bundle 22 and pulled through a tibial tunnel 24 formed in the tibia 26, as shown in FIG. 3. As shown in FIG. 4, as the graft is pulled through the tibial tunnel 24, the surgeon rotates the bundle labeled posterior cruciate lateral bundle 20 into the posterior cruciate lateral position 28, and rotates the bundle labeled posterior cruciate medial bundle 22 into the posterior cruciate medial position 30, thereby creating the soft tissue required for both the posterior cruciate lateral bundle 20 and posterior cruciate medial bundle 22.

With the posterior cruciate lateral bundle 20 and the posterior cruciate medial bundle 22 created in the knee and appropriately oriented, the bundles 20 and 22 are tensioned independently using a tensioning device 32 that couples to each bundle 20 and 22. As seen in FIG. 5, the posterior cruciate lateral bundle 20 is tensioned with the knee 11 in a first position 34 of approximately full extension. As will be appreciated by one of ordinary skill in the art, first position 34 may include a range of extension at or near full extension. Specifically, while in this first position 34, the tensioning device 32 applies tension to the posterior cruciate lateral bundle 20 while the posterior cruciate medial bundle 22 is left in an untensioned position. As shown in FIG. 6, the knee 11 is then flexed into a second position 36 so that there is approximately 90 degrees of flexion between the femur 12 and the tibia 26. As will be appreciated by one of ordinary skill in the art, second position 36 may include a range of flexion at or near 90 degrees. While in this second position 36, the tensioning device 32 applies tension to the posterior cruciate medial bundle 22 while the posterior cruciate lateral bundle 20 is left in an untensioned position. In one embodiment, the external tensioning device 32 cycles the separate bundles 20 and 22 under tension as the knee 11 is moved between the first position 34 and the second position 36. Alternatively, two separate screws are inserted as posts in the tibia 26 to individually secure the bundles 20 and 22 so that tensioning of the bundles 20 and 22 is performed without the tensioning device 32 by moving the knee 11 between the first position 34 and the second position 36.

FIG. 7 illustrates tibial fixation of the posterior cruciate lateral bundle 20 and the posterior cruciate medial bundle 22 with a screw 38. The fixation is performed after the graft 10 has been tensioned and before the tensioning device 32 has been removed. In an alternative embodiment, the tensioning device 32 is used to secure the bundles 20 and 22 with any screw type fixation device. In other embodiments, alternative fixation devices may be used to secure the bundles 20 and 22. After the bundles 20 and 22 are secured to the tibia 26, the surgical wound is closed using standard techniques.

Accordingly, the above described invention enables the creation of two separate bundles using a single graft that is positioned using a single tunnel. The single tunnel enables a less invasive operation than known methods of replacing a posterior cruciate ligament. Moreover, the present invention enables the kinematic tensioning of separate bundles thereby providing a more effective and successful ligament replacement

As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.

Claims

1. A method of replacing a posterior cruciate ligament of a patient, said method comprising:

preparing a graft having a first end including a first bundle and a second bundle and a second end wherein the first bundle and the second bundle are joined as a single bundle;

preparing a single femoral tunnel in the femur of the patient and a single tibial tunnel in the tibia of the patient;

securing the second end of the graft in the femoral tunnel; and

securing both the first bundle and the second bundle of the first end of the graft in the tibial tunnel.

2. A method as recited in claim 1, wherein the graft includes a bone patellar tendon bone graft having a femoral bone plug.

3. A method as recited in claim 2, wherein the femoral bone plug is secured in the femoral tunnel and the graft is prepared to provide for separate bundles in the tibial tunnel.

4. A method as recited in claim 1, further comprising tensioning the first and second bundle with a tensioning device coupled to the first and second bundle.

5. A method as recited in claim 1 further comprising tensioning the first bundle while the patient's knee is in approximately 90 degrees of flexion prior to securing the first bundle.

6. A method as recited in claim 1 further comprising tensioning the second bundle while the patient's knee is approximately in full extension prior to securing the second bundle.

7. A method as recited in claim 1 further comprising positioning the first bundle in a posterior cruciate lateral position in the tibial tunnel while positioning the second bundle in a posterior cruciate medial position in the tibial tunnel prior to tensioning the first and second bundle.

8. A method as recited in claim 1, wherein the graft includes a hamstring graft secured to a femur of the patient to provide a bundle that is independently tensioned after femoral tunnel fixation.

9. A method of replacing a posterior cruciate ligament, said method comprising:

harvesting a graft tissue from a patient;

preparing a single tibial tunnel in a tibia of the patient and a single femoral tunnel in a femur of the patient;

securing the graft in the femoral tunnel;

separating the graft into a posterior cruciate medial bundle and a posterior cruciate lateral bundle;

inserting the posterior cruciate medial bundle and the posterior cruciate lateral bundle through the tibial tunnel;

positioning the posterior cruciate lateral bundle in a posterior cruciate lateral position in the tibial tunnel while positioning the posterior cruciate medial bundle in a posterior cruciate medial position in the tibial tunnel;

tensioning the posterior cruciate lateral bundle while the patient's knee is in approximately 90 degrees of flexion, and tensioning the posterior cruciate medial bundle while the patient's knee is approximately in full extension;

securing the posterior cruciate medial bundle and the posterior cruciate lateral bundle in the tibial tunnel.

10. A method as recited in claim 9, wherein the graft tissue includes a hamstring graft.

11. A method as recited in claim 10, wherein the hamstring graft is secured to the femur to provide a bundle that is independently tensioned after femoral tunnel fixation.

12. A method as recited in claim 9, wherein the graft tissue includes a bone patellar tendon bone graft having a femoral bone plug.

13. A method as recited in claim 12, wherein the femoral bone plug is secured in the femoral tunnel and the graft is prepared to provide for separate bundles in the tibial tunnel.

14. A method as recited in claim 9, wherein tensioning the posterior cruciate medial bundle and tensioning the posterior cruciate lateral bundle further comprises tensioning the posterior cruciate medial bundle the posterior cruciate lateral bundle with a tensioning device coupled to the posterior cruciate medial bundle the posterior cruciate lateral bundle.

15. A graft for replacing a posterior cruciate ligament of a patient, said graft comprising:

a first end comprising a first bundle and a second bundle;

a second end wherein the first bundle and the second bundle are joined as a single bundle;

a single tibial tunnel formed in the patient's tibia; and

a single femoral tunnel formed in the patient's femur, the first bundle and the second bundle of the first end configured to secure within the single tibial tunnel, and the second end configured to secure within the single femoral tunnel.

16. A graft as recited in claim 15, wherein the first bundle is in a posterior cruciate lateral position in the tibial tunnel.

17. A graft as recited in claim 16, wherein the second bundle is in a posterior cruciate medial position in the tibial tunnel.

18. A graft as recited in claim 15, wherein the first bundle is tensioned with a tensioning device while the patient's knee is in approximately 90 degrees of flexion.

19. A graft as recited in claim 15, wherein the second bundle is tensioned with a tensioning device while the patient's knee is approximately in full extension.

20. A graft as recited in claim 15 further comprising a bone patellar tendon bone graft having a femoral bone plug configured to secure in the femoral tunnel.