Hi, I'm Kathy Bithock from Rocky Vista University. Today we're going to do an ultrasound consult on intersection syndrome and the findings that we will see. The dorsal wrist exam is a fairly big exam, but for this consult, we'll just concentrate on part of it. The first three compartments are what is of concern today. The first compartment contains adipopolysis longus and extensor polysis brevis. The second compartment has extensor carpe radialis longus and brevis, and the third compartment contains extensor polysis longus, and you can see the graphic here showing that. The ultrasound on the left is actually a mirror image of that, but that does show Lister's tubercle, which is our starting point in doing a wrist ultrasound. It's an easy landmark to find, and that's going to separate your second and third compartment easily. Let's walk through the areas where there can be intersections of these tendons. The first and second compartments have an intersection. As you can see on the graphic, it's just proximal to the wrist joint here, and in the ultrasound images, you can see the four tendons that are involved in both of the pictures. In the second one, they're just circled, so they can be seen a little bit easier. This is a normal ultrasound of these four tendons at their intersection. The other intersection that comes into play is where the second and third compartments intersect, and sometimes people can get confused on which compartment goes on top of the other compartment. Just remember that the second compartment is always deep in these intersections. So here are both the graphic and then some images of the second and third compartment at the intersection, which is a little bit more distal to the intersection of the first and second as is seen on the graphic here. So what do we see on ultrasound in people who have intersection syndrome? There are several things that potentially we can see. You can see thickened tendons. You can see edema within the tendons. You can see evidence of tenosynovitis or fluid within the tendon sheaths. The example that we have here on the left is simply that same normal image of the second and third compartments intersecting. On the right is an image of somebody who does have intersection syndrome of those compartments, and you can see there's increased fluid in the tendon sheath, especially around EPL. EPL is also a little bit thickened. Compared to the contralateral side in this patient, ECRL and ECRB may have been slightly thickened as well, and that certainly can happen.

3rd Edition, CASE 59

3rd Edition

Wrist

intersection syndrome

ultrasound findings

dorsal wrist compartments

tendons

tenosynovitis