Surgery Spotlight: Type 2 Duplicated Thumb Reconstruction-Surgery Spotlight: Type 2 Duplicated Thumb Reconstruction

Surgery Spotlight: Type 2 Duplicated Thumb Reconstruction

Video Transcription

Hello, my name is Kevin Chung, Professor of Plastic Surgery at University of Michigan. I have a great interest in congenital hand reconstruction.  Today I will demonstrate to you the technique used for type 2 duplicated thumb reconstruction. So this is a usual situation.  This is a nice baby from Burma who come in with, I mean if you have duplicated thumb, the way we classify duplicated thumb is really simplistic.  It's that the thumb has two joints, distal phalanx, proximal phalanx, and metacarpal. If it's split at the level of the distal phalanx, then it's either one or two.  Two is completely split, shared, ahead of the proximal phalanx, and we go approximately become four. Four is split the proximal phalanx. Most commonly it's type four.  This one is not particularly fitting in any of the classifications. What do you think this one is? It's a three. Okay, so it's kind of split, shared, shared proximal phalanx.  So the issue is that one is on top of the other. The x-ray, I'm going to look at the x-ray, the x-ray showed that this radial thumb seemed  to be pretty nice nail, as Dr. Nallon said. It's actually more centered, however, the other one, the other one is bigger.  So the question is, how do we creatively make one, and the issue is that typically what we like to do is that we like to preserve the ulnar collateral ligament, particularly  right here, because ulnar collateral ligament is usually stronger. But this one is type three, so the ulnar collateral ligament is not going to be affected.  Regardless of what we do, if we can preserve the ulnar collateral ligament so the thumb is more stable, then typically the thumb is pretty functional.  The radial collateral ligament is not as important, because we usually don't grip things by pushing it this way.  So my inclination is still the fundamental principle to not violate the ulnar collateral ligament area, and then they have to take imperfections and keep this one, and ultimately  this one will be okay. I mean, this could be stable. It will look pretty good when we finish.  I'm going to look at the x-ray and see how it goes. This is a type three with shared metacarpal, I mean, shared proximal failings, in which  I need to remove the metacarpal, probably not violate the joint, but I certainly need to remove the, not metacarpal, but the proximal failings of the removed digits.  An issue is that, which one do we need to remove? So I'm going to shoot it again. So this is a radial one. This one's a radial one.  The radial ones seem to be a bit more formed, and I'm not going to violate the ulnar collateral  ligament, but still, if I remove the ulnar one, I'm going to violate the ulnar collateral ligament because I need to go more proximally, whereas the radial one is not so important,  but the radial one, we just need to reattach the thenar muscle. So I'm going to take out the radial one and keep the ulnar one.  The standard way to do things for us is that we need to make a curl in the incision. I want to preserve more skin, so it'll be much easier closure. We do that.  We should be able to close that, right? Actually, we're not going to be able to close that because the thing is kind of tight over here.  Yeah, so we really have to come up more, yeah. It's very important to keep as much skin as possible, so what we're going to do is we're going to come up just a little bit more.  Always get more skin just because you can always excise, but if you get it too tight, we cannot.  So once we remove this one, there's going to be a hole on that side, and the skin can drape very nicely. Skin hook, please.  The key point is that Dr. Nellon's going to make the incision, and we're going to go dorsal. We're going to use our incision dorsally to define the bony structure, and then under  thoracoscopy perhaps we need to be sure that we remove the correct amount of bone, and I don't want to go all the way to the joint, but one of the issues is that when we go up  here, we have to look at the thenar muscle, which we need to detach and then reattach to the proximal phalanx on the ulnar digits, because the thenar muscle's going to come up.  So we're going to do our identification of structures dorsally, make a dorsal incision, go all the way, we're going to go all the way until we get to the extensor mechanism  and define our bony structure. Okay, so Dr. Nellons is going, keep going, going until we see something, what we're seeing is fat still. Okay, there you go.  Now it's the extensor mechanism. Shine the light, yeah, bring the, right in the middle here. Skin hook to me. Thank you. Skin hook. Hold this. Okay.  So what she's going to do is now she sees the extensor mechanism, she's going to define that. There you go. Okay. I'm sorry, make the incision a bit lower.  Okay guys, so what you're going to see is that you're going to see extensor mechanism coming to this thumb.  You're going to see extensor mechanism coming to this thumb, and what you're going to see here should be some muscle attachments. We haven't seen it yet. A little bit of bone.  So let's see how it goes. Okay, let's go. That's the fat, that's skin. Let's see how it goes. Now we're going to see some thenar muscles, but let's see.  Okay, so we see still bone here. Bone is very soft. So what she's going to do is that the extensor tendon to this thumb is not useful to us anymore.  She's going to transect this one, and then make an incision here, and lift up this extensor tendon that we may or may not need to use it for some purposes.  So it's a spare part kind of operation. So what she's going to do is that, yeah, she's going to cut the, just extensor mechanism, not the bone. Okay. Just extensor tendon.  Pick up please.  Pick up please.  So you're going to take this thing, just this thing off. Yeah, she's going to take off the extensor tendon. Extensor tendon to this finger, come down here. Come in between.  In between right here.  The reason that we're going to lift up the extensor is so that we can see the bony structures. Just lift up this thing. You can see the bony structures. I'm sorry, hold on.  So she can see the bony structures underneath there, so we can get a precise osteotomy. So we're going to lift up the extensor tendon.  Good. Keep going. A bit more.  Good. Give me a free air, please. Okay, hold this one for a second. So now we can see the crevice in between these two bones.  And I think that would be helpful to get another thoracoscopy to be sure that we are cutting the right thing.  Give me a 15, please. I'm going to go just a bit more approximately to see what's going on down here.  Okay, so here's a tendon to that. Here's a tendon to this. And the question is, you know, what's going to happen here?  So what we're going to do is we're going to use a knife and split the proximal phalanx all the way until it's all incision. Give me a free air, please. Free air, and then 15 blade.  So you're going to split until here, and you kind of angle it down this way. Interesting that there's no athena muscle attached to this.  So the key maneuver is that she starts her analysis. Essentially, it's going to go back and forth, back and forth, kind of turning the other way.  She's going to kind of rock this thing. Make sure you hold her thumb. You hold her thumb. She's going to rock back and forth. Come towards me just a little bit.  She's going to rock back and forth to cut the bone. And there's no need to... Yeah, exactly.  Let me see that. Oh, yeah, this is persona blade. Let's just see how tough it is. It's a hard bone. Yeah, it's hard.  Okay, maybe hard bone. Give me the bone cutter, please.  It's a sharp one. It's never been used before, it seems like. Because I generally don't use this. It's a good base now, I think.  Is that good? Yeah, that looks great. I'm sorry. Let's clean her chest a little bit.  So usually a knife can go through the cartilage, but her bones are pretty hard. Gently, very gently remove the bone, cut between the bone or the proximal phalanx,  and then we may just complete some of them using a knife. Let's see. It's a little bit more, right? We keep a little base, that's okay. Can I get a bone cutter?  Let's cut just a little bit more. We're going to keep a little volus cortex, it's okay. Give this a bit more stability.  Okay.  So we're going to take this bone off.  Let's be careful. Don't need to struggle with that.  Okay, that's fine. Now what we're going to do is a complete incision. It will come off pretty easily. Give me your hand please.  Yeah, please.  What we're going to do now is to complete our incision. Now what I'm going to do is make an incision, and then lift up the skin flap.  Lift up the skin flap so we can close.  Angle your knife straight down.  So essentially what we're going to do is that we're going to remove the bony component while saving the skin for coverage. That's nice skin. You don't have to go deep.  You don't have to go deep. You just need to get off enough skin for coverage. There you go. Good. Good. Okay. Now the skin is going to come off.  The skin is going to come off. The key thing about duplicated thumb reconstruction is you want to preserve the ligamentous structures so you can sew it back.  In this particular case, we need to establish to see whether there's laxity after we remove the bone.  And typically when you have collateral ligament structures on the radial side, you want to keep them so we can reattach it. In this case, it doesn't seem to be the case.  Let's see how it goes. Good. Okay. Still got some pretty good bone stock here to support that one. The skin will redrape. And the issue is that it's just unstable. Maybe a tad bit.  Which means that this tendon will be very helpful.  We can just tuck it in there. So now what we're going to do is that this thumb, this is a fairly small, it's a bit unstable.  So what Dr. Nellens is going to do is that she's going to reattach it. Don't like that, it's easier to go this way. Don't bend your knee though.  What she's going to do is that she's going to tuck this tendon in, but at the same time she's going to sew it both at the distal phalanx and the proximal phalanx.  So you kind of essentially cinch it, rather than pulling it radially, you can cinch it. Pick up to me please. It's tight.  We're going to do it, we're going to put a tiny pick up, we're going to tie it down and then we're going to cinch it also to the approximate phalanx.  Scissors for me, please.  What we're going to do is, how about let's just do this, just kind of cinch it down to something like right here. Yeah.  So it doesn't act as an extensor? Yeah.  And come through it? Yeah, so just tug it down. Yes.  Okay, so we just really just improvise to stabilize the radial side of the IP joint with this tendon.  That should recreate some type of stability to that joint. Okay, that should be fine.  Good, that's very nice. So now, what we're going to do is that we're going to close the incision and we have very nice skin.  This beautiful skin we saved over here is going to be gorgeous. So, let's close the skin and we'll rearrange the soft tissue. So give Dr. Nolan a stitch, please.  Let's kind of tug this one. See that? That one fits in the corner pretty nicely. Just put a tugging stitch and we'll rearrange the skin.  What size chromic is this? 4-0. Okay, let's see how it goes. Maybe it's okay.  Can I have a 5-0, please? Sure. So what we're going to do is some tugging sutures and eventually we're just going to migrate, march it down. We don't want a lot of redundancy.  Pick up, please. We have to do a Z-plasty at the end. Alright. You want to keep the skin? You want to keep all the skin?  Put another one here. Put another one there, see? Put another one and kind of see how it goes. This is a 5-0. Awesome, thank you. Make sure you close that, okay?  A little tear there.  Now we're going to shift direction, we're going to try to close it in a longitudinal fashion so you can make up for that skin redundancy.  So now we have this extra skin, because this side is longer than the other one. So what we're going to do is that we're going to cut it off.  I'm going to put a cast on this kid, primarily because I don't know what the family situation is. We really need to protect this one.  If we have extra skin here versus here, what we're going to do is just make an incision here. Let's actually move this down. 15 to me, please.  We're just going to close it. I'm sorry. Close it in a different direction.  You don't want to keep chasing this one all the way down. So you change the direction for this one. So what I'm going to do is this one.  I just want to match that.  I'm just going to close the rectangle. That's going to match that.  And this one will fit.  So to reiterate what the key component of this one is, the key component is that if one can save the ulnar side, ulnar finger, save that,  because the importance of the ulnar collateral ligament for pinch. And the important component is that you use dorsal incision, go down to the extensor mechanism.  Lift up the extensor mechanism so you can see the bony structure. After you see the bony structure, then you need to decide how much bone to remove.  And the fourth instructional point is that you want to see whether there are... If you go into the joint, you want to be sure that you took off the ligamentous structure.  Make it a bit deeper. Make a deeper suture. You want to take off the ligamentous structure that's attached to the thumb that you're going to remove.  Because once you remove the thumb, this ligament is going to be lax. This joint, you want to reattach it. Reattach that ligament. So you want to be careful.  If the ligament is attached to the thumb that's removing, you've got to keep that.  We didn't show that in this case because it's not necessary, but in other cases it would be necessary.  In this particular case, you can see that the collateral ligament is weak on the radial side.  So we used the extensor tendon to create a new collateral ligament on that side so that it will be more stable.  Another issue to remember is that make sure that the skin flaps are sutured nicely. A nice contour around the defect and that will preserve a nice aesthetic closure of the thumb.  And of course, the last point to remember is that the thumb needs to be well perfused after the operation.  In some cases, when the ligament reconstruction is necessary because of the laxity, I would generally put a pin in. But in this particular case, the thumb IP joint is quite stable.  We augmented with the extensor tendon graft and the thumb is very stable. Therefore, a pin is not necessary.

Video Summary

Professor Kevin Chung from the University of Michigan discusses the surgical technique for reconstructing a type 2 duplicated thumb, using a case of a baby from Burma. He explains the classification of duplicated thumbs and outlines the approach for reconstructing the thumb, emphasizing the preservation of the ulnar collateral ligament for stability. The procedure involves determining the right thumb to remove, addressing the shared components between the duplicated thumbs, and reattaching muscles and ligaments for functionality. The process includes careful dissection to define structures, bone removal while maintaining skin for closure, and a technique to stabilize the thumb joint using an extensor tendon. The aim is to achieve a functional, aesthetically pleasing thumb after surgery, ensuring good perfusion and stability without the need for pin insertion in this particular case. The procedure is completed with careful suturing for optimal cosmetic results.

Asset Caption

In this video, Dr. Chung performs part 2 of duplicated thumb reconstruction.

Surgeon Kevin Chung, MD This product is not certified for CME.

Keywords

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Kevin Chung MD; Memben

thumb reconstruction

duplicated thumb

ulnar collateral ligament

surgical technique

thumb stability

Kevin Chung