So, this is the view you usually have as you slide more posteriorly from the AC joint, not changing the axis of your probe. You'll see the trapezius superficially, the subscapular, sorry, the supraspinatus muscle deep to that. Your acromion laterally, and the scapula makes the, up the bottom of your screen here. The suprascapular ligament here overlying the notch, and then deep to that is the nerve. So, this was done with a sonocyte export probe a couple years ago, and this is, since these are both normal findings, this is just a normal video from a Samsung. So, a little bit better resolution, and you can see the nerve next to the artery, but using power Doppler, you're going to be able to differentiate the nerve from the artery. So, here there's no abnormality of the nerve or vessels within the notch. There was no atrophy, I should say fatty atrophy of the supraspinatus muscle belly compared to the overlying trapezius, and that's something you're going to look for when you're suspecting a cuff tear, looking at the relative echogenicity of this muscle belly compared to the trapezius. And if I had seen any fatty atrophy here of the supraspinatus, I would also get a short axis view of both the trap and the supraspinatus. So, now getting to the spinal glenoid notch, and we're going to definitely go into a little more detail here than I would typically. It also has a ligament, but it's a little bit harder to see, and I don't think I highlighted it in my pictures, but there's, the vessels still run with the nerve, and as to get to this area from the area we were just in, we need to sweep and slide our probe inferiorly and laterally. What's going to happen as the probe moves into position, though, is the spine of the scapula is going to, we're going to have to pass over it. So, this video highlights that, meaning going from our suprascapular notch, then seeing nothing but black because of the bone, and then getting to our spinal glenoid notch. And the way that I'm trying to do this is I'm thinking about the orientation of the nerve. So, I've already tried to follow this suprascapular nerve in short axis, keeping it in the center of my screen, and that is forcing me to move my probe laterally, and it gives me an idea of which direction I'm going to need to move over the spine of the scapula to find the spinal glenoid notch. The other thing you need to do to see this notch as well as you can is to wag superiorly, and that means we're bringing our probe up and over the spine of the scapula and then angling it upwards. And if we don't angle upwards, we're not going to see that most superior aspect of the notch because it's going to be shadowed by our, by the spine of the scapula and the acromion. So, this is our patient, and this was the first view I saw when I was looking at him, and, you know, I'm just going to take you through my thought process here. I was like, okay, well, I can see the notch. There's a hypoechoic, you know, circular mass there, I think, but I don't know if that's a cyst, a vessel, or a mass at this point. To orient ourselves, this is the glenoid. This is the humeral head. This is our deltoid and our infraspinatus. The labrum is the hypoechoic kind of triangular thing right here. Now, so how can I differentiate those things, a cyst, a vessel, or a mass? Well, the first thing I do is I use color or power Doppler to see if it's vascular. And so, this was my patient, and that didn't really differ. I mean, it doesn't appear to be vascular on our patient, and this is a Samsung image from a normal patient that just differentiates, again, the vessel from the nerve. And the next thing we can do, though, to differentiate vessels from a nerve is to use dynamic internal rotation and external rotation. Now, with a normal patient, that should dilate a vessel. And seeing that vessel dilate, if the patient is in external rotation, you could definitely falsely call a cyst if you don't then internally rotate them. Because if you have them fixed in external rotation, this is what you're going to see. Until you internally rotate and allow that vessel to go back to normal. Whereas, in our cyst case here, this remains relatively static. Now, it can fluctuate a little bit if the stock is communicating with the glenohumeral joint, but there shouldn't be too much variation in size with external and internal rotation. Another thing to optimize our image, when I'm here, pretty much flush with the patient's skin. And what this is doing is it's giving me a really good view of the glenohumeral joint and the labrum. But my angle of my beams are not optimized to see this notch. I mean, the base of this notch is angled upwards. And I need to toe in medially to optimize that. And that's for two reasons. One, that's going to get my beams to bounce back to my probe and give me the clearest image. And it'll also, because the beams bounce back, they have to pass through the soft tissue above the bone twice. And that's going to give us a clearer image of our cyst or whatever structure is above the bone. So, anytime you can keep bone below a soft tissue structure and keep that bone parallel to your probe, that's going to help too. Finally, the one other thing you can see here going from the left to the right is that the patient's in an internally rotated, maximally internally rotated position here. So, that moves our intra, it moves our tendon from over the cyst to kind of lateral to the cyst. And then there's less posterior shadowing from that infraspinatus tendon. So, all those things can help you kind of optimize your image in the spinal glenoid notch. And so, this was, you know, what I saw and what I concluded. And I also have a short axis, or sorry, a long axis on the spinal glenoid notch image here to the right, there was a hypoechoic, well-circumscribed avascular mass within the spinal glenoid notch with a stock tracking from the posterior glenohumeral labral tear. And you can see the tear because of the way the stock moves right through the labrum. The suprascapular nerve was displaced superficially, and we'll get to that next. And there was no fatty atrophy of the infraspinatus muscle. And I know a lot of cases the suprascapular nerve is displaced or actually kind of squashed down underneath the cyst. And that may be why this patient was able to tolerate this cyst without any weakness or suprascapular neuropathy. There's also, I also had a question when I was looking here, is this also another nerve? And I couldn't, you know, I wasn't sure. There are two branches. There's an inferior branch that runs to the joint. I don't know if it's shown in this image, but I wasn't sure. So I didn't call it.

2nd Edition, CASE 48

2nd Edition

Shoulder

ultrasound imaging

suprascapular notch

nerve conditions

color Doppler

probe positioning