"Little lost ligament" may explain why some ACL surgeries fail

November 6, 2013 8:34 PM

In 1879, a French gynecologist / knee expert suggested that a tiny but very important body part existed. No one seemed to be in any hurry to test his hypothesis, although there was some desultory interest shown in the 1970s and 2000s. This Tuesday, two Belgian researchers (Steven Claes and Johan Bellemans) confirmed that the anterolateral ligament (ALL) exists and that about 97% of us have it. (Press release; abstract.) "The doctors wanted to know why some patients with ACL tears suffered from pivot shifts, or knee collapses, even after successful reconstructive surgeries. ... Patients with ACL tears were likely suffering knee collapses because of ALL injuries."

How could this be missed so long? Yes, it is small, but it’s not really that much smaller than the Lateral Collateral Ligament also known as the LCL, at least according to the photographs, and that ligament is a well-known troublemaker. ... However, doctors themselves are quite cavalier about what appears to be a massive medical oversight. University of British Columbia professor Dr. Wayne Vogl says the ligament has continued to be missed “because of all the other stuff that is there.” Alrighty then.

Also: One doctor argues that this is more of a "rediscovery" than a new discovery. “We’ve known for years that a thickening around the area where the ALL is located has a role in knee stability,” he said. “While I don’t think this is necessarily a breakthrough, I think it’s a good reminder that we need to refocus some attention on ACLs that don’t respond well to surgery.”

posted by maudlin (15 comments total)

So it sounds like the key discovery is that a piece of tissue which was just considered to be a "thickening" of tissue is, in fact, ligamentous, and has some anchoring relationship to the surrounding bone structures.

Pretty cool that we're still learning things about the gross anatomy of the human body!
posted by darkstar at 8:50 PM on November 6, 2013 [8 favorites]

The researchers gave a presentation last March that has a bit more detail: abstract.

Segond's 1879 paper (yes, in French).

Oh hey wait: a different set of researchers also investigated this in 2012, but it looks as if they disagree on the exact location and weren't looking at the ACL connection.
posted by maudlin at 9:04 PM on November 6, 2013

At first I wondered: a gynaecologist and a knee specialist? ... and then I thought, well, of course! - when you're squinting up the tunnel of love, what's right beside your ear? It's the next obvious thing to look at if you get bored with vaginas. So yeah, natural progression of study.
posted by Mary Ellen Carter at 10:26 PM on November 6, 2013 [16 favorites]

if you get bored with vaginas

.....Nope, sorry, I'm afraid you lost me there.
posted by Greg_Ace at 11:07 PM on November 6, 2013 [13 favorites]

My wife will be having ACL surgery next year. Thanks for this post maudlin!
posted by hat_eater at 11:17 PM on November 6, 2013

Histologic analysis revealed a discreet structure

So that's why it was overlooked! The ALL is going to have to speak up if it wants to get noticed.
posted by daveliepmann at 12:36 AM on November 7, 2013 [4 favorites]

Excuse me doctor, but that's not my knee.
posted by three blind mice at 1:34 AM on November 7, 2013 [1 favorite]

A hundred and thirty-four years. One hundred and thirty-four years. Woo. Gooooo science.
posted by BiggerJ at 1:44 AM on November 7, 2013

One hundred and thirty-four years.

Not surprising coming from a profession that took hundreds of years to decide that maybe washing hands before an operation might be a good thing.
posted by MartinWisse at 3:32 AM on November 7, 2013 [6 favorites]

The thing that fascinates me (who knows nothing about anatomy beyond what you learn in school and from reading the sports section) is that some nontrivial portion of the population is missing one ligament or another and it's largely irrelevant to them, when normally there's such pressure to talk about whatever a 'normal' body is, as if the 3% of the population missing this ligament are defective. 3% maybe doesn't seem like much, but a full 14% percent of people don't have the tendon commonly used for Tommy John surgery.*

*See, this is how I learn anatomy from the sports section.
posted by hoyland at 5:11 AM on November 7, 2013 [2 favorites]

Oddly enough, the ALL is not the only semi-mythical anatomical feature of the human knee; in fact, when I first read the headlines around this discovery, it was the other feature I thought they were talking about.

I have a PCL injury that I got from a nasty fall while skiing - a small tear in the posterior cruciate ligament, behind the knee. As a result, my right kneecap is somewhat unstable, and the key to improving its performance, so my physical therapist told me, is strengthening the VMO, the vastus medialis obliquus. He gave me exercises to do this, and yes, the knee is definitely better.

So I was somewhat surprised to later learn that the VMO may not exist.
posted by kcds at 5:19 AM on November 7, 2013 [1 favorite]

My understanding is that the human knee is basically just a dog's breakfast of various bits and bobs, none of which are completely standard, and very little of which is discretely laid out like you see in an anatomy text book. It doesn't surprise me that if this is legit no one really noticed it.
posted by Chrysostom at 6:50 AM on November 7, 2013

My understanding is that the human knee is basically just a dog's breakfast of various bits and bobs, none of which are completely standard, and very little of which is discretely laid out like you see in an anatomy text book. It doesn't surprise me that if this is legit no one really noticed it.

You're not a professional, right?

(I loved your comment!)
posted by Jody Tresidder at 9:01 AM on November 7, 2013

This is very interesting. I have a chronic ACL tear that causes me a lot less trouble than it ought to, and I wonder if my ALL is helping to pick up the slack.
posted by joannemerriam at 9:52 AM on November 7, 2013

Ha, no. My wife is a doctor, and I do KNOW orthopedic guys.
posted by Chrysostom at 10:36 AM on November 7, 2013