AP Biology class blog for discussing current research in Biology

Tag: Anterolateral Ligament

Doctors Discover New Ligament in Knee

Many already know about the four ligaments in the knee- medial collateral, anterior cruciate, posterior cruciate, and lateral collateral.  However, according to a New York Times article, doctors in Belgium have identified a fifth ligament in the knee called the anterolateral ligament (A.L.L.).  This ligament was originally speculated about in the 19th century by a French surgeon named Paul Segond.  While Segond did note evidence of its presence and function, he failed to name it, and its presence was forgotten.

File:PaulSegond.jpg; (US Public Domain Tag)


However, it has been discovered again and given a proper name.  The A.L.L. on the outside, front portion of the thighbone and continues down to the beginning of the shinbone.  This placement allows it to stabilize the knee and prevent it from collapsing inward.  Previously, doctors thought that the A.L.L. was just a continuation of the illiotibial band, but it is clear now that it is a completely different entity.

A few years ago, Dr. Claes and his colleagues noticed that some patients that had underwent and recovered from A.C.L. surgery had problems with their knees collapsing.  He guessed at the existence of a new ligament and searched for the ligament in donated knees; he easily found it.  Now doctors are beginning to practice procedures for torn and sprained A.L.L.s.  Thanks to Dr. Claes’ rediscovery of Segond’s original hypothesis, doctors will now be able to fully treat all ligaments in the knee.

How many ligaments did you really tear? For me, it’s now 4!

Newfound ligament in the human knee

Newfound ligament in the human knee; Photo by Kasey Katz

As of November 5, 2013, a new ligament has been discovered in the human knee by two Belgium biologists, Doctor Steven Claes and Doctor Johan Bellemans.

These doctors were curious as to why patients who have had previous ACL surgery continue to experience sensations where their knee will “give out” during certain activities.

Their curiosity led them to research and ultimately, astonishing results. These two doctors are credited with the discovery of an unknown ligament, now recognized as an Anterolateral Ligament (ALL).

This newfound ligament also suggests a connection with ACL injuries. As studies now show, ACL tears are a product of ALL injuries. Did you tear your ACL? Does that mean you also tore your ALL?

This research could signal a breakthrough in ACL tear repairs.

Which is why these two doctors are already one step ahead; Dr. Claes and Dr. Bellemans are now working on creating a surgical procedure to repair ALL injuries.

Being a patient who previously tore my ACL, MCL, and Meniscus, I found this discovery particularly interesting because chances are… I also tore my ALL.

That’s just fantastic.

Learning about this newfound ligament, I now wonder if I will need to get another repair on my knee, later in life, to fix the “giving out” sensation I encounter from time to time.




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