Torn ACLs

There’s new help for an injury that used to be career ending for athletes. Researchers at the University of Virginia Health System have uncovered a way to fix unsuccessful surgeries to repair the Anterior Cruciate Ligament (ACL) by using what they call the “plug” technique. Their findings appear in the June issue of the Journal of Arthroscopy.

The ACL is one of the four ligaments in the knee that holds it in place. Athletes, particularly females, frequently tear their ACL during sports. Reconstruction of a torn ACL involves drilling small holes or “tunnels” in the femur and the tibia. This allows surgeons to attach connective tissue grafts with screws. This also is where problems can occur. Misplaced or poorly positioned tunnels often cause ACL surgeries to fail and lead to knee instability. Second surgeries can fail to repair the ACL when new tunnels open into the old ones. The researchers found that “plugging” the tunnels the second time around addresses both of these problems.

“More than 70 percent of all cases of failed ACL reconstructions are due to poorly positioned tunnels,” said Dr. Mark Miller, associate professor of sports medicine and lead author of the study. “With our technique, we can fill these tunnels with cylinder-shaped bone grafts that provide stability and allow us to successfully complete the revision.”

The bone grafts are human allograft bone plugs that come from a tissue bank and are offered in various lengths and diameters. They are freeze-dried and do not require refrigeration. Before use, the bone grafts are sterilized and re-hydrated for placement inside the patient’s tunnels. According to Miller, these “plugs” allowed their revisions to be done in one stage, shortening their patients’ recovery times from one year to six months. Also, the patients who received this technique avoided additional bone loss.

Other techniques have been described that revise failed ACL surgeries, but according to Miller, many of them are too time consuming and technically difficult. Bone grafts used for the “plug” technique are easy to obtain and even easier to use. They offer good structural support to the knee and allow for re-drilling.

Miller and his researchers have been following 10 patients who had second surgeries using the plug technique. After one year, five patients had resumed active lifestyles or sports activities. “While it may not be for everyone,” Miller says, “using bone grafts to 'plug' tunnels is a healthy and viable way of giving people with ACL injuries a second chance.”

This article was released by U.Va. Health System News on June 6, 2005.