Anterior cruciate ligament (ACL) reconstruction done by using a replacement ligament from a cadaver may have a high failure rate of 24% in younger patients under 40 years of age, according to a US study.
The findings, from researchers at the Mississippi Sports Medicine and Orthopedic Center, presented Thursday at the American Orthopedic Society for Sports Medicine annual meeting, in Orlando, Florida, raise the question as to whether other alternatives should be explored for younger ACL patients.
The ACL is a key ligament inside the knee that helps to keep it stable and stops the shin bone from sliding forward. Located in the center of the knee joint, it runs from the thigh bone to the shin bone through the center of the knee. A sudden direction change can cause the ACL to tear. To repair a torn ACL, a surgeon replaces the damaged ligament with a new one, either from a cadaver or the patient's own body.
For this particular study, 64 patients aged 40 years or younger who had undergone ACL reconstruction with a replacement ligament from a cadaver were followed for at least two years.
The grafted ligament was found to be a failure in 15 people (23.4 percent). This means the patients had to undergo a second reconstruction due to injury or graft failure or low scores on a combination of orthopedic function test.
The failure rate in an older group was only 2.4 percent.
"This failure rate in this young, active population is exceedingly high when compared to a previous study that looked at failure rates of cadaver replacement ligament in patients older than 40," said Dr. Gene Barrett of the Mississippi Sports Medicine and Orthopedic Center in Jackson, who was involved in the study.
"In no way are we saying that (cadaver) grafts should not be used anymore," said Dr. Kurre Luber, who presented the study findings in Orlando. "We are just suggesting that maybe (doctors) should reconsider or use caution when putting a (cadaver replacement ligament) in a young active patient because our data certainly suggests that they are more likely to fail," he added.
Dr. Derek K. Lichota, an assistant professor of surgery at Texas A & M Health Science Center College of Medicine and a sports medicine physician at Scott & White said the study has a number of unanswered questions. "They don't tell us if the patients were braced postoperatively," he said. There is no information on when the second rupture occurred or the failure rates in specific subgroups of patients. Also, the researchers did not describe the particular technique used for each replacement.
"My concern is that we may be comparing apples to oranges," said Dr. William Levine, chief of sports medicine at New York-Presbyterian Hospital/Columbia in New York City.
An estimated 800,000 ACL tears occur each year in the United States, with the number of ACL replacement surgeries equally high. Golf legend Tiger Woods is perhaps the latest well-known casualty. He recently announced that he would be undergoing ACL surgery this year, and that would require him to miss the rest of the 2008 season.