Imaging a shoulder dislocation using ultrasound

Learn how to use ultrasound to help you identify and treat shoulder dislocations.

Peter Croft, MD
Peter Croft, MD
5th Jul 2018 • 4m read

Dealing with a shoulder dislocation? No problem! By the end of this video, from our Ultrasound-Guided Nerve Block Masterclass, you'll know how to use ultrasound to identify shoulder dislocations, and make them easier to reduce with a simple ultrasound-guided joint injection.

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Master the use of ultrasound to guide your nerve block procedures with our Ultrasound-Guided Nerve Block Masterclass course. You'll learn how to identify and anesthetize nerves in the neck, torso, and lower extremities with the help of ultrasound, and build an appropriate nerve block protocol within your hospital.

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Video Transcript

[00:00:00] There are two key reasons to use ultrasound in shoulder dislocations. The first is to find and to diagnose the shoulder dislocation. We've all been in that situation, is it out or is it in? The last thing you want to do is order an x-ray, wait the ten minutes for the x-ray tech to come and then wait another ten minutes until it's loaded up and then try to determine is it out, is it in, is it anterior,

[00:00:30] is it posterior? An ultrasound of the shoulder will tell you this in a moment's time. The second reason to ultrasound a shoulder is to aid in the injection of anesthetic, into the shoulder joint itself, that is to assist you with the reduction procedure. In this module, we will solely focus on learning how to find and locate the dislocation. The shoulder joint itself is fascinating. It's the most mobile joint in the body.

[00:01:00] It moves up, it moves down, it moves left, it moves right. Let's hearken back to our orthopedic training for med school. Most shoulder dislocations are anterior. They move towards the front of the body. This translation forward of the humeral head is the movement of least resistance. When shoulders move posteriorly, the rotator cuff and the deltoid muscles act to inhibit

[00:01:30] this movement. That's why posterior dislocations are so much less common. In terms of probe position to locate the shoulder dislocation, your probe will be located in the posterior aspect of the shoulder joint, along the scapular spine. The best way to do this is to have your patient try to sit upright, I know it's hard sometimes, but talk them through it and shrug their shoulders back. This ergonomic good posture position creates anatomic

[00:02:00] consistency. It's also incidentally the position to have your patient in for their subsequent reduction procedure. In terms of probe selection, the two most commonly used are the linear probe and the curvilinear probe. For larger patients, you'll need the curvilinear probe here on the right. This probe, as you see, is bigger and it goes deeper into the body. The linear probe on the left of your screen doesn't go as far

[00:02:30] into the body, so it won't give you the image you need in the grand majority of patients. So, let's look here at where our probe is on our patient. To orient you, the patient's head here is facing forward. The back is here, to the right of the screen. You can see gel is already applied to our target area. Here, watch as your operator identifies the scapular spine. The probe is going to be placed directly on

[00:03:00] the spine and then moved downward. You'll see here as your operator internally and externally rotates the shoulder. Quickly, let's watch this again as it's really important. Scapular spine, probe on the spine, slide just a bit downward and then if you can, if the patient lets you, subtle little movements,

[00:03:30] not likely this vigorous, but subtle little movements in and out of their arm. The corresponding ultrasound image created can be seen here. Remember that the area that is closest to you on your screen is actually the back of the patient, so you are looking forward. You are looking towards the front of the patient. Here's your scapular spine. Notice the hyperechoic rim of the spine and the shadowing beyond it.

[00:04:00] What do you think this is here, the circular hyperechoic rim? Well, that's the humeral head sitting right where it should be in the glenohumeral joint. And as you see, when I press play, you'll see this humeral head move back and forth in a comfortable fashion. Here's that internal and external rotation. There's the nice crisp rotator cuff muscle on the top of the humeral head and as you saw that humeral

[00:04:30] head moving back and forth comfortably in the socket. So, to remind you, deep is front. The further away the objects appear on your screen, the more on the anterior surface of the patient's body, they lie. So, an anterior dislocation, looking from the back of the patient, should be further away from you than a normal shoulder anatomy. So, let's look at what an anterior dislocation

[00:05:00] looks like. Again, recognize your hyperechoic bone. This is your scapular spine and then notice the humeral head is going to not be where it should be, right next to the scapular spine but rather further away from you, anterior location. There's your humeral head. Here it is in video form. You're not being able to move the patient back

[00:05:30] and forth as much as you were before because they're in pain, but you can see hyperechoic humeral head here and then the spine of the scapular here.