there is nothing new under the sun — or under the knee.
Two knee surgeons at University Hospitals Leuven set the medical world on its ear recently when they fully described a previously enigmatic knee ligament.
Orthopaedic surgeons Dr. Steven Claes and Dr. Johan Bellemans gave the world its first full discussion of the anterolateral ligament (ALL) when they published some of their findings in the Journal of Anatomy.
They say it could turn out to be important for those with anterior cruciate ligament (ACL) tears. ACL tears are common among athletes in pivot-heavy sports such as skiing, soccer, basketball and football.
It’s actually a rediscovery, says Dr. Robert LaPrade, chief medical officer with the Steadman Philippon Research Institute. The ligament was first described in 1879 but was largely ignored until people began doing ACL reconstruction surgery after the 1970s when surgeons began reconstructing the ACL arthroscopically. In other words, people started doing surgery inside the joint rather than outside the joint. A whole generation of surgeons has been doing it that way. It’s always been there.
“It’s been discovered before, but was called by a different name than our colleagues in Belgium are calling it,” LaPrade said.
Still, it is significant, LaPrade said.
“When you have ACL reconstruction surgery, your knee will still shift or pivot a little bit. It’s probably some of the structures in the outside of the knee that are causing some of the problem,” he explained.
The newly renamed ligament is found in probably all human knees, LaPrade said.
For the 5 to 15 percent of patients who have ACL reconstruction, ignoring the outside of the knee and, by extension, the anterolateral ligament, means the repair isn’t as tight as it used to be, LaPrade said. Than can cause some difficulties when they’re participating in pivoting and cutting sports, he said.
For people who are experiencing a little bit of shift, it could be the structures on the outside of the knee. There are several things that could be causing the problem, not just the newly named anterolateral ligament, LaPrade said.
Claes, in Belgium, is a new researcher and recently defended his Ph.D. thesis. When his university released his Ph.D. defense, it got picked up and created something of a media frenzy about the discovery of a new body part.
LaPrade said he has been inundated for information requests from colleagues and editors of textbooks and journals, who were caught unaware by all the media frenzy.
Why this matters to you
Even after successful ACL repair and rehabilitation, some patients’ knees continue to buckle and give way during activity. For the last four years, Claes and Bellemans have been trying to figure out why.
Their research began with an 1879 article by French surgeon Paul Segond, the first to describe a “pearly, resistant, fibrous band” at the knee joint. Claes and Bellemans meticulously studied 41 cadavers, and the ligament was present in 40. Further research found that when a knee buckles or gives way in patients with an ACL tear, it could be caused by an injury in the ALL ligament.
Claes and his team are not the first ones to notice the ligament, of course. In the past, a Montana surgeon, Dr. Ron Losse reconstructed the structure that Claes is referring to as the anterolateral ligament. It even became known at the Losse ligament, LaPrade said.
Dr. Jack Hughston called it the mid-third lateral capsular ligament. Hughston said it may have some role in providing some rotational stability to the knee — keeping it from shifting after ACL reconstruction.
The research could signal a breakthrough in treating patients with serious ACL injuries. Claes and Bellemans say they are working on a surgical technique to correct ALL injuries. Those results won’t be ready for several years.
“I believe that Dr. Claes’ group is on the right path to determine if the small percentage of patients who still have some pivoting after an ACL reconstruction could possibly benefit from a reconstruction of the anterolateral ligament. However, further studies are necessary to validate this and all of us look forward to seeing the results of those studies over the next five to 10 years,” LaPrade said.
What they’re talking about
Put your hand to the outside of one knee. Next to your kneecap there’s a small ledge and a shallow pit. If your fingers are in the right place, that’s your ALL, a pearl white piece of tissue about an inch and a half long that scientists think might help provide stability when you flex and twist your knees.
The ALL connects the thigh bone to the shinbone on the outside of the leg. Claes and Bellemans say it probably helps to keep the knee from rotating inward.
Bellemans is the lead surgeon on the study, and he says about 80 percent of his patients with ACL tears also have injured their ALL.
Staff Writer Randy Wyrick can be reached at 970-748-2935 and firstname.lastname@example.org.