All right, so we'll move now into our most distal segment, which will be the thumb. And I'll give you a little talk about that, and Dr. Hutchinson's going to be doing the dissection. So the thumb. So again, we're trying to put together a surgical plan for these kids, looking at the elbow, forearm, wrist, fingers, and thumb. Our three main tools are the soft tissue releases, the tendon transfers, and the joint stabilizations. And for the thumb, we really use all three of these tools. And I think the thumb is, number one, the least studied. Like we have a lot of things that study wrist flexion extension. The thumb is very difficult to study because you have the rotational component that goes with it. You have CMC, MCP, and IP, plus rotation of the CMC. So I find it the most difficult of everything that we've talked about today. So with that being said, it's still an important portion of doing this surgical planning to try to do the multi-segment upper extremity surgery. So the indication for surgery is thumb and palm that interferes with pinch function. And the most common thing is that they can't clear the index finger. And the second thing is that if we do tendon transfers, you have to have sufficient voluntary control to allow pinch to occur. And then the third reason we sometimes do it is for hygiene. And that would be more for the severely involved patient, usually skeletally mature or adult, and that it's a simple hygiene problem that you can't get the thumb out. So Dr. House did a classification back in the 80s, and I still use it. He was my predecessor at Gillette Children's Hospital. I don't think it's perfect, but I do think it helps you think about the concepts. And the main concept is to think about what's tight. So if the primary problem is the thumb adductor, meaning your adductor originates on your third metacarpal, it inserts on the first metacarpal. So if the ray of the thumb is being pulled across the palm of the hand, that's your thumb adductor. So if that's the primary deforming force, then that's a type 1 thumb and palm. Oftentimes surgery is not indicated. If they have adequate extensors and adductors to clear their thumb, many of these kids don't need surgery or sometimes will use some botulinum toxin to decrease the spasticity in the adductor. If they can functionally clear their index finger, just simply getting some pull across the palm is not a surgical indication, because remember, if you release the adductor or lengthen it, you're going to lose strength. And these guys' pinch is important. So sometimes a little spasticity in their thumb isn't bad. It allows them to pinch as long as they can clear that index finger. But if they can't clear that index finger and you see them when they're trying to grasp things that their thumb is so far across the palm of their hand that they can't flex their index finger, then it interferes with their grasp function and they can't pinch with it. And then surgery would be indicated. A type 2 thumb and palm, again, you're looking at what are the deforming forces, what are spastic. So it's not only adduction across the palm of the hand, but it's also flexion of the MCP joint. So these kids, it's not only the adductor, but it's the FPB. So those are your two main deforming forces. The third type, and I love this picture because it's from 1967 before we had HIPAA, and it's Dr. House's picture. He used to take a piece of masking tape and put the date and the patient's name on it. And I don't think Jess R. knows anymore from 1967. But this is how he would demonstrate it, is that if you have a type 1 thumb and palm, the first rate adducts across the palm of the hand and then you compensating by hyperextension through the MCP joint, that's a type 3 thumb. So instead of having like a type 2, you would have a secondary deformity of MCP flexion. In these individuals they have a compensatory mechanism of MCP extension. And some of them will dislocate their MCP joint. And then a type 4 tends to be your spastic quad. So not only are their intrinsics tight in the thumb and palm, but their FPL is tight too. And sometimes you don't actually really know this until you bring your wrist up because obviously your FPL crosses your wrist too. And you can see that it's not only your intrinsics, it's your extrinsics. All right. So we have our toolkit. We have release of what's tight, augmenting what's weak, and stabilizing the joints. So we apply those principles. So we release what's tight. And some kids get some remarkable first web contractures. Some people think this is a bigger problem than others. Some people do a simple Z-plasty. Some people do a four-part Z-plasty. Some people think the deformity is more kind of in the coronal plane than in the actually like first web. So again, that's a clinical assessment. You have to see which muscles are tight. Is it the thumb adductor, adductor plus FPB, or the FPL as well? So the adductor can be released off its insertion. And if you do that, you lose pinch strength because you're disconnecting its insertion. So if you do it through a first web Z-plasty, you have to be in a patient that's pretty less, that is not very functional. You're okay if they lose that pinch strength. I don't know if you can see that very well. There's a Z-plasty in the cleft. There's the adductor releasing the fascia. Sometimes you can release some of the first dorsal interosseous as well. There's a head of the first dorsal interosseous that comes across your first web. The adductor is exposed. The adductor can be tenotomized, can be intermuscularly lengthened. You can preserve the muscle fibers and just take the tendinous portion down if you want to preserve some of that muscle strength. And then interpose your Z and increase your adduction of the first ray if you do an adductor release alone. The other mechanism for, or technique for doing an adductor release, and I would say this is for a higher functioning patient where you want to preserve the adductor strength. You have a higher risk of recurrence this way because you aren't tenotomizing the muscle. But you take it off its origin as Metab originally described. You're leaving your ulnar motor branch to it. You're leaving your median nerve motor branches and you're releasing its origin and sliding that muscle. And you can visually see it on people that are really tight. And if you splint them afterwards, probably the origin goes down on the second metacarpal. So this is kind of like your flexor pronator slide. You're releasing that origin, splinting them for a month, and it heals with a lengthened origin. And you can either include your adductor only for a type 1 or adductor and FPB for a type 2. So here's a case that shows the Metab. So again, you can see the adduction of the ray across the palm. It interferes and does not clear. I mean, even asleep with an Illumiform hand, it doesn't clear the first, the index finger for abduction and extension. And Hutch will show this a little bit with this technique. You identify the transverse portion of the adductor and there's a second head of the adductor that comes down more likely, and you can release that as well. So you want to release those tight structures. And then the question is whether to augment the weak structures with a tendon transfer. And again, this is an assessment of what you have voluntary control over. Dr. Manske described an EPL rerouting, and I think this is a favorite of many surgeons. If you think about the vector of your thumb as it comes past Lister's tubercle here, if you look on your own thumb and you have Lister's tubercle here, your EPL is going to work as an extensor, but it's a secondary adductor. If you do this in the operating room when you pull on it, you'll see that it extends the thumb, but it adducts the ray. Whereas if you pull your EPL down into the first compartment, it extends your thumb, but it adducts your ray because then it's radial to that side with its vector. So an EPL rerouting would be a take off the insertion of the EPL, and again, Hutch will show this, and there's variations on how you do this. If they have an MCP hyperextension deformity like this person did, I would only put it into the metacarpal head. I would not put it across the MCP joint because you don't want to augment that and make it into a type 3 thumb where they hyperextend through their MCP. And immobilizing this particular person, I used a pin to help hold that adductor so you take them from this posturing with them asleep in maximum extension to this posturing. Really, really easy. Yeah, so that's a good question. Actually, I learned how to do this in tetraplegia when I do key pinch. The trick is to put your thumb, to hold your first web, and you put it across your thumb metacarpal, and then you're going to put it transversely just along the same lines as your adductor into your second metacarpal. And so you're going to feel it like this and get the pin into the second metacarpal. It has to do with the rotation of the thumb, which makes it really hard to hit the second metacarpal harder than you would think. If this is the base and you're trying to increase your intermetacarpal angle, I think if you put it decently, like here's your metacarpal on this particular, if you put it decently distal, and I'll use one, I'd push on it and see if it moves and if it's spastic, whether it really holds it. Just to tell you how bad I can get, Graham Lister described a pinning with a W in between the two. Oh, yeah. I can't figure out how you can do it. How you get it out, ever. Yeah. That's like in the old bone block days where they'd stick a piece of bone block between your first and second metacarpal just to keep your thumb out. And then a month in a cast. So this would be elbow extension, forearm supination, thumb out of palm, wrist extension. And then, just to include it, a nighttime brace. So I do one month in a cast, one month in a brace. And the month in the brace, they have a brace at night that includes the elbow. They have a brace during the day that doesn't. And this includes supination to neutral. They have the brace off three to five times a day for active range of motion, and then they do nighttime bracing only and do full ADLs. And you can see here, there's probably a little bit of swan necking. I mean, it's pretty mild. But this is a patient who had an FCU, EPL rerouting, adductor release, and nothing on their MCP joint. So the third tool we have is joint stabilization. I think Michelle just said she does a lot of MCP fusions. You can do an MCP fusion if the physis is open, if the epiphysis is ossified, and then fuse the epiphysis to the distal end of the metacarpal. Or you can do a joint capsulodesis, which I guess I don't have a picture of. So why don't we talk a little bit about those techniques, and we'll have Dr. Hutchinson do some demonstrations.

surgical planning

thumb

tendon transfers

joint stabilizations

thumb deformities