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Wrist Kinematic VISI/DISI
1.5k Plays2 years ago
Covering VISI and DISI. DISI injuries occur due to SL injuries vs VISI occur due to a VISI injury. .
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Transcript
Introduction to Visi and Disi
00:00:09
Speaker
Hi guys, I'm Josh. And I'm Miranda. And we are Hand Therapy Academy. We are going to talk today about Visi and Disi. It's a complicated subject we get asked a ton about with our students who are trying to prepare for the CHT exam. So let's get into some complicated stuff on what is for us a Sunday morning at 6.30. So let's get into it.
00:00:29
Speaker
All right, let's get
Understanding DISI
00:00:30
Speaker
cracking. So Josh, tell me first, let's start with the more common, the dizzy deformity. Tell me kind of how that occurs and what goes on with the carpal kinematics.
00:00:40
Speaker
So in a vissi-dissi, the lunate is supposed to be the stable anchor in the center of that proximal carpal row. And when the scapholunate ligament is ruptured or detaches or is injured in some way and loses its stability, the scaphoid, which normally pulls towards flexion, disconnects and it drops forwards. And then the lunate, which is connected to the trichretrum as well,
00:01:06
Speaker
It goes into extension posturing because it's not tethered to the scaphoid anymore. So it's a dorsal. It goes dorsally or into extension. So it's a dorsal intercalated segmental instability. It goes unstably, dorsally because it's not tethered to that more volar and flexion posturing scaphoid. Right. And so this is the dizzy deformity and how this injury typically occurs. So a scaphalune injury, it typically occurs with a twisting motion. So
00:01:34
Speaker
if you've had your wrist twisted aggressively, that sometimes can cause a cell injury to occur. And we'll see those like functional, you see those with someone who's maybe detained by the police and they're grabbing on or opposite the person who's the police officer is hanging on in that torque of someone trying to get away twists their wrists. And so that's a common one, maybe hanging out under the handle of a motorbike and things kind of get out of control and you didn't let go and it twists that wrist also. Yes.
Understanding VISI
00:02:00
Speaker
So that's DC. Now let's talk about VC or Vissi.
00:02:04
Speaker
Okay, less common, but that one is the opposite mechanism. That lunate is tethered to the scaphoid and loses its tether to the tricretrum. And so when their general posturing affects the position of the lunate, the scaphoid carries it forward into flexion, volarly, and it detaches entirely from the tricretrum going dorsally or into extension. So it's a volar because the lunate travels volarly. So it's a volar intercalated segmental instability. That's a mouthful.
00:02:34
Speaker
Yeah. So determining which way these occur is really just based on the position of the lunate. Would you say that's correct? Yeah. Yeah. Just identifying that. And it kind of seems counterintuitive because if it's moving with the skateboard, that means that LT was damaged. And opposite, if it's moving dorsally, that means the skateboard was damaged. That's kind of maybe a little counterintuitive, but follow the lunate. Yeah. That's why we say follow the lunate, what direction it's going, and then that can help you to determine if it's a VC or DC.
00:03:01
Speaker
And then with the VCs, these typically occur when you're falling backwards on an outstretched hand. So you fall backwards to catch yourself. So your wrist is more in that pronated position as opposed to the supinated position. So we see these on somewhat times when people fall maybe out of a chair or they're falling backwards for whatever reason.
00:03:21
Speaker
Yeah. Yeah. Reaching back to catch themselves. That palm lands on the ground. You get a little LT injury there and that scaphoid drops, excuse me, eliminate drops of older lace. So yeah, same, same concept, just everything in opposite. Yeah. So that is the, um, BC deformity. Yeah.
Treatment Strategies for DISI
00:03:38
Speaker
So let's talk about treatment. What would you do for someone who came in with, um, an SL rupture and they have, um, uh, DC dorsal intercalated segmental instability?
00:03:48
Speaker
Yeah, so for these, we're focusing on the carpal friendly movers. So we're going to be focusing on doing range of motion within the dart throwers plane. So we know that's very safe. We're going to avoid firing of the ECU because we know that the ECU can actually make the condition worse. And then we're going to be possibly, depending upon their progressing with the dart throwers motion, doing
00:04:09
Speaker
some isometrics, so doing isometric strengthening of the carpal friendly movers. Hopefully you hope stabilize that area. So if it is say maybe grade one or grade two where it's a smaller tear, those are safer exercises to do with the goal of kind of re-approximating the SL together so it can heal. And then also these patients oftentimes will go into a splint where they'll be immobilized and then they'll come out to do the exercises.
00:04:37
Speaker
And so lots of good stuff there, kind of a lot to unpack. We talked about, you mentioned dart thrower's motion. If you don't know what that is, think about the action of literally throwing a dart across the room. It is flexion of the wrist with ulnar deviation and extension of the wrist with radial deviation. And that's because wrist flexion
00:04:56
Speaker
encourages scaphoid flexion, and owner deviation encourages scaphoid extension. And so pairing those two together means the scaphoid doesn't actually go anywhere. Same thing, wrist extension and radial deviation have opposite impacts on the scaphoid. And so the scaphoid doesn't go anywhere, it's kind of locked in place. And so it doesn't separate from the lunate, stressing that repair or the
00:05:18
Speaker
the stressed ligament, so it keeps that ligament short instead of stretching and attenuating it. So we do dart throwers for an SL injury, and they talked about friendly and non-friendly muscles for things. We'll get into that in another talk a little bit, but it is good to know that like ECU, I don't want to strengthen that because that's going to encourage rotation of the scaphoid away from the lunate. Right, definitely. And then the other thing that I forgot to mention is doing proprioceptive exercises.
00:05:46
Speaker
we know that these ligaments can sense the stability or they sense proprioceptive input. So once they get that input, they tend to tighten because of the proprioceptive input fibers on the ligaments. So doing proprioceptive exercises such as the disc stacker, there's lots of phone apps you can get on your phone to utilize so the patient can do them at home, can also be part of the SL program or SL HEP.
00:06:13
Speaker
Yeah. Yeah. Um, lots of proprioceptive stuff, lots of good research showing that doing that wrist stability stuff, sometimes even isometric where you're just doing a light axial load, those kinds of things can really turn on the proprioceptive system and you get good tightening of those ligaments as a result. So yeah, really good for that. Stressing the wrist. Yeah. Very safe exercises to do. And then of course, have your patient, you know, you're always listening to your patient. Is this increasing your pain? Is this helping? You know, so you're getting that subjective input as well from the patient.
00:06:42
Speaker
Yeah.
Treatment Strategies for VISI
00:06:43
Speaker
And so let's talk about what we would do to treat an LT ligament injury. What would that look like? Yeah. So an LT it's the opposite of a dart throwers motion. So we're going to be doing a reverse dart throwers. So that is sometimes hard for people to grasp, you know, cause we're used to doing that dart throwers motion, but then doing the opposite of that is a little tricky. So you're basically going more into an ulnar deviation with flexion and then
00:07:11
Speaker
the opposite would be so when you're going into extension with more of the radial deviation.
00:07:19
Speaker
I think we got that a little bit backwards. So the dart throwers is wrist extension and radial deviation. The reverse dart throwers is wrist extension and ulnar deviation. So it's kind of like putting it in this weird corner thing there. So wrist extension and ulnar deviation and wrist flexion and radial deviation. And that's really going to load that ECU to go into extension and ulnar deviation at the same time.
00:07:42
Speaker
in the opposite of dart throwers that is flexion and ulnar. So just change one of the two directions and that gets you the reverse. Super awkward motion. Is that what I said? No, I didn't say that. I'm sorry. So, okay. Now, why don't you just say that one more time so everybody can grasp that? Yeah. So let's recap. Dart throwers is wrist flexion and ulnar deviation. That's a very comfortable natural movement. Lots of space to do range of motion. And then we come back diagonally or obliquely into wrist extension and radial deviation.
00:08:12
Speaker
If I change one of those two descriptors, and so I do wrist extension, but with owner deviation and wrist flexion with radial deviation.
00:08:23
Speaker
So that's a really tough movement. There's not a lot of range of motion available there, but it really loads that ECU quite a bit. And that's an LT friendly movement or an LT friendly tendon. So wrist extension and ulnar deviation and wrist flexion and radial deviation. And that also loads FCR, which can be sometimes a friendly muscle at LT. That's a tricky one. But that movement is the opposite of dart throwers. Yeah, that's super awkward. And I think awkward to teach your patients, right?
00:08:51
Speaker
Yeah, I have a hard time teaching them dart throwers, because a lot of times they don't quite get that plane of movement. So I'll have them do it with their unaffected arm first. And I'll go over the affected and I'll actually give them like parameters with my hand kind of making that diagonal plane for them to stay between as they don't touch my hand as you're tracking there. The other one is like, sometimes I have to just dependently do it and see if they can kind of figure it out as I'm doing it passively. And then we go from there. Yeah.
00:09:17
Speaker
Yeah, something I found that's really easy for them to grasp is telling them to pick up like something light because that gives you that dart thrower's plane and then it's somewhat functional. I think sometimes when I tell them to throw a dart, they're like, what? I don't throw darts, you know, unless they do, obviously. So just picking up a cup gives you that motion. But with, with the LT injuries, I focus more on doing like the isometric strengthening because I think it's so awkward to do
00:09:38
Speaker
reverse start throwers. Yeah. Yeah.
Conclusion and Contact Information
00:09:42
Speaker
All right. Our goal is to keep these short. So we are keeping this one to 10 minutes. If you have any questions or have any suggestions, reach out to us at info at handtherapy.com or find us on handtherapyacademy.com and we'd love to hear from you guys.