Tulane graduate students Dominic Roy and Cooper Bruce were in their anatomy lab dissecting a cadaver when they saw something they didn’t recognize: a small muscle that sits just above the hip.
The students couldn’t find it in their textbooks, and their professor, R. Shane Tubbs, couldn’t identify it either.
The students and the professor joined WWNO’s Louisiana Considered intern Ryann Goldberg to discuss their discovery.
The following transcript has been edited and condensed for clarity.
RYANN GOLDBERG, BYLINE:
Dominic and Cooper, walk us through the moment you first saw the muscle. What stood out to you?
DOMINIC ROY: We were doing a mass dissection of all the cadavers in the Tulane anatomy laboratories, and while we were dissecting very deep toward the pelvis, I saw a small muscle that we didn't really talk about in our morning meeting. We had spoken about another muscle that Dr. Tubbs said was kind of controversial among anatomists, which is located more towards the edge of your hips. The muscle that I saw looked like this, but it was actually towards the inguinal region of the hip. And so I pointed it out and called Dr. Tubbs over, and he was as confused as me. And so we re-dissected a majority of the cadavers and found it in many of them.
GOLDBERG: What were you thinking when you realized it hadn't been identified before?
COOPER BRUCE: I think the big thing is, it's hard to understate the excitement you feel when you see something that you can't identify on the spot. So obviously, as we were a lot younger back then, we kinda just said, "Oh, it's probably just something else," or, "It's probably hidden on some other finding, some other paper that we just haven't seen yet." Or, "Oh, let's just ask Dr. Tubbs, like, surely it'll be somewhere." And the more you realize it's something you haven't seen before — that sort of excitement is hard to describe.
GOLDBERG: Professor Tubbs, let's go to you. What was your reaction when they came to you with this muscle? How did it feel to potentially have a scientific discovery on your hands?
R. SHANE TUBBS: Well, thank you, Ryann. I think, first and foremost, most people don't understand that there are lots of anatomical variations in the human body. We see those day to day in my lab — in the teaching lab in particular. They're not that uncommon. But I will say that, second, most of these variations have been well described. There's literature that you can find on the variants of the human body.
So when someone thinks that they found something that has not been described before as an anatomical variation, it has to undergo a lot of scrutiny. I think we have students often that will, during the teaching labs, come up and ask, "What is this?" and "Have you seen it before?"
And the answer is usually yes. In this particular case, in this area, there's no described anatomical variation. So, I was a little taken aback that we don't know what this is. And as I kind of intonated, we first think that maybe this is just part of another regional muscle, so it's not something special.
With some additional dissection, and then when we started looking at not a few, but hundreds of cadaver sides, we found that this is indeed something that has not been described before in the extant medical literature, and decided to publish it. So, I think it's a good feeling.
But, in the beginning, you have to raise the threshold level very high and make sure that you're actually describing something that is new and not something that is misleading you as a separate muscle.
GOLDBERG: What did you learn about this muscle as you continued your research? Why does it not appear in every one that you examined?
TUBBS: So with most anatomical variations, you don't see those in every single anatomical donor that we dissect. So that is not uncommon. The answer to your question, why do we not see this in every one, I don't know that we have an answer for that.
It could be genetics. It could be just luck of the draw. And with this one in particular, we looked at it a little more in detail, and it has a very close relationship to the front of your hip and the capsule around the hip. And we know that its next-door neighbor, Dominic, you mentioned there's a separate muscle layer that also attaches to the front of the hip joint.
So in that particular muscle layer, we see some patients who come in with pain in the front of the hip that's not related to the hip joint, but it's related to potentially this little muscle attachment. So we extrapolated to our new finding, and we suggest in the paper, although we don't have clinical evidence yet, that by having a similar attachment and being nearby to another muscle that does something very similarly, that this newly described muscle attachment might, in some patients, have a similar role in some pathologies.
GOLDBERG: Once you confirmed the muscle had not been identified before, what were your next steps?
TUBBS: The first step was to do a large sampling to see what the prevalence is in the population, because it could be that we just happened to find a muscle that hasn't been described before in a single dissection. So you have to extend that. We also had some international collaborators from South Korea, Japan and Europe who also checked in their labs — in their dissections — to see if they could also see this.
So that helps us support our findings that we have additional geographic regions around the world that also have this similar muscle attachment. We looked at the muscle not only grossly with our eyes, but we also did histological sections to make sure that there wasn't anything non-muscular about it.
So our histo findings, or our microscopic findings, support that this is regular skeletal muscle just like the surrounding muscles, so it's not something pathologic. And then those histological findings also showed that the muscle has a very intimate attachment relationship with the surrounding tissue of the hip, so the capsule of the hip.
And, as I mentioned before, other similar muscles that have that same type of relationship have been described as causing pain syndromes in and around the hip joint.
GOLDBERG: Dominic and Cooper, this is quite the discovery for two college students. What's next for both of you? Will you continue scientific research?
ROY: I just started my master's at the med school downtown in the Department of Structural and Cellular Biology. Actually, Dr. Tubbs is one of my professors. So that's a one-year program, and I just recently applied to LSU and Tulane Medical School and am waiting to hear back from them.
BRUCE: Similar path for me, but I'm currently in my master's degree in neuroscience, and I'm also on the pre-med track. And even though it's pre-med, I still do research on campus, and I think it's a really sort of interesting part of academic life. And hopefully I'll have the opportunity to continue on a new project in whatever graduate school I end up in.
GOLDBERG: What does this discovery mean for medicine? How will it change how some conditions are treated, specifically snapping hip syndrome?
TUBBS: That's a great question. Thank you, Ryann. The jury's still out because we've just gone through step one, which is identification of the structure.
We've described the anatomy, and I think some next steps before we can jump into whether or not it plays a role in snapping hip syndrome would be imaging. So, can you see this little slip of muscle on MRI, for example, that we could then find patients who have hip pathology, hip pain, similar snapping hip type symptoms, and then correlate it — is this muscle also present?
And, if that's the case, then potentially clinicians who treat hip pain or treat snapping hip syndrome could then target this area. Those will be the next steps, but we're very early in our understanding of any role that this muscle plays. So for right now, we just have described its morphology, what it looks like, and it’ll now need to undergo rigorous investigation by the clinical world.
