Bicortical tibial fixation of ACL grafts

Abstract

A method of securing a graft in a bone tunnel, in which graft is secured within the tunnel at both the entrance and the exit ends of the tunnel to provide bicortical fixation of the graft in the bone. Interference screws or other fixation devices are used to secure the graft within the tunnel. For tibial tunnel fixation using an interference screw, the back end of the distal screw is angled so that it closely approximates the angle of the outer tibial tunnel rim. The distal screw is non-cannulated to prevent hematomas from being formed by blood flowing from the tibial tunnel into the surrounding soft tissue. The proximal screw has a restricted cannula to minimize the flow of synovial fluid entering the tibial tunnel. Advantageously, the space between the two screws fills with blood to promote faster healing and incorporation of the graft in the tibial tunnel.

Description

[0001]This application claims the benefit of U.S. Provisional Application Ser. No. 60 / 078,391, filed Mar. 18, 1998, and is a continuation-in-part of U.S. patent application Ser. No. 09 / 243,995, filed Feb. 4, 1999, now abandoned, the disclosures of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to endosteal fixation of a ligament by device insertion and, more specifically, to methods and devices for bicortical tibial fixation of anterior cruciate ligament grafts.[0004]2. Description of the Related Art[0005]When a ligament becomes detached from a bone, surgery usually is required to reconstruct the ligament. Often, a substitute ligament or graft is secured into bone tunnels to facilitate incorporation and permanent attachment.[0006]Various methods of graft attachment are known, including the use of interference screws to secure the graft against the walls of a tunnel drilled through the tibia and...

AI Technical Summary

Benefits of technology

[0009]The present invention overcomes the disadvantages of the prior art and achieves the foregoing objectives by providing apparatus and methods for bicortical fixation of ligament grafts, whereby the graft is fixed at two cortical locations (“bicortical”) within the tibial tunnel using a pair of fixation devices. The invention advantageously improves fixation strength, and also minimizes the likelihood of damage to the graft and the bone tunnel during and after fixation, such as by preventing widening of the bone tunnel by graft motion. In addition, as described below, bicortical fixation improves the healing environment of the ligament graft.

[0010]The fixation strength of the graft is advantageously increased by engaging the graft against the denser, cortical bone at the ends of the tunnel. The fixation method and devices of the present invention preferably are designed to match the anatomy of the tibial tunnel, and to provide fixation at the original insertion point of the ligament. The fixation devices also are designed to minimize graft abrasion, while maximizing fixation strength.

[0011]Further, the preferred fixation methods and devices advantageously restrict blood loss from the fixation site to improve healing and graft incorporation. The preferred fixation modes advantageously plug both ends of the bone tunnel, and leave the internal bone tunnel cavity unobstructed between the plugged ends. Accordingly, the bone tunnel cavity, through which the graft passes, is allowed to fill with serous fluids to promote faster healing and enhance graft incorporation within the tunnel.

Problems solved by technology

The above-described secondary fixation of the graft to the exterior surface of the tibia is disadvantageous in that it is subject to abrasion from external elements, and is generally less secure than internal fixation.

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