Patent Application
20140303729
The present invention relates to the use of an interference wedge to secure a bone plug of a tendonous graft in place in a bone tunnel.
During the repair of an anterior cruciate ligament (ACL), a tendonous graft is formed by a tendon between two pieces of bone. The bone pieces are fit into a tibial tunnel and a femoral tunnel so as to interconnect the tibia and femur.
Often times a screw is used to secure the bone piece in the appropriate tunnel. A problem encountered is that the screw engages and at least partially tears the tendon interconnecting the bone pieces. This weakens or destroys the interconnecting tendon.
Accordingly, it is an object of the present invention to avoid the drawbacks of the prior art procedures.
This object is accomplished by the use of a wedge which is used to engage on one side with a femoral tunnel or a tibial tunnel and on the opposite side engage with a bone plug. This is accomplished by forming a wedge being substantially semi-circular on one side and flat on the opposite side.
The semi-circular side is made of trabecular metal having a series of roughened protrusions varying in height from 0.25 to 2.5 mm, and preferably 1.25 mm in height. The roughened semi-circular surface securely fixes the bone plug in place. Further, the roughened surface causes the expected bone regeneration of approximately 2 mm to attach to the wedge and securely fasten the wedge in place in the bone tunnel.
The substantially smooth underside of the wedge contacts the bone plug and positions the plug in place. The smooth surface of the wedge avoids the possibility of chewing up the graft as is experienced by the use of an interference screw.
At a trailing edge of the wedge is a hook that engages the bone plug or is used to loop the bone tendon. This helps guide the bone plug in place in the femoral tunnel.
A hole in a center of the proximal end of the wedge is used for engagement by a long slender driver. The driver will engage the wedge in a slot in the bottom of the hole to rotate the wedge into position in the bone tunnel by rotation of the driver. The driver is also used to push the wedge to its final resting position. The driver is then backed away from the wedge and removed.
The positioning of the tendonous graft may be accomplished by passing the bone plug at one end of the graft through the tibial tunnel until reaching the femoral tunnel. The wedge is then engaged with the bone plug in the femoral tunnel. The plug is then moved into position in the femoral tunnel by the slender driver until reaching its final position as determined by the surgeon.
Accordingly, it is another object of the present invention to secure a tendonous graft in place between a femur and a tibia in a respective bone tunnel.
It is another object of the present invention to secure a tendonous graft in place between a femur and a tibia in a respective bone tunnel by the use of a wedge engaging on one side with the bone tunnel and on the opposite side with the bone plug.
It is still yet another object of the present invention to secure a tendonous graft in place between a femur and a tibia in a respective bone tunnel by the use of a wedge engaging on one side with the bone tunnel and on the opposite side with the bone plug with the surface engaging the bone tunnel being curved and covered with trabecular metal and the side engaging the bone plug being substantially smooth.
It is another object of the present invention to secure a tendonous graft in place between a femur and a tibia in a respective bone tunnel by the use of a wedge engaging on one side with the bone tunnel and on the opposite side with the bone plug with the surface engaging the bone tunnel being curved and covered with trabecular metal and the side engaging the bone plug being substantially smooth and a hook at a proximal end of the wedge engaging at least one of the bone plug and the tendon of the graft to assist in the positioning of the tendonous graft.
These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description taken in conjunction with the accompanying drawings.
The following drawings illustrate examples of various components of the invention disclosed herein, and are for illustrative purposes only. Other embodiments that are substantially similar can use other components that have a different appearance.
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and to
The upper surface 16 of the wedge is curved, semi-circular in shape having a radius of approximately 4.5 mm. Towards the distal end and the lateral side edges, the upper surface 16 tapers along a curved line to the lower surface 18. The lower surface is substantially flat. A distance between opposed edges 18a and 18b of the lower surface 18 is approximately 9 mm.
The upper surface 16 is coated with trabecular metal substantially across its entire surface. The trabecular metal approaches the size and distribution of various shaped spicules of bone found in cancellous tissue. This type of surface fosters the growth of bone into the surface of the wedge for a secure anchoring of the wedge in a bone tunnel.
At the proximal end 14 is a flat base surface 20 extending substantially perpendicular to the lower surface 18. The base surface 20 includes a hole 22 which extends approximately 3 to 5 mm into the wedge. A slot may be located at the base of the hole 22. Extending from the base surface 20 towards the bottom surface 18 is a hook 24. The hook 24, as shown in
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The foregoing description should be considered as illustrative only of the principles of the invention. Since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
