Thank you so much, that was a terrific talk. Our next speaker is Dr. Tom Kiefhaber from Cincinnati, who is a fantastic surgeon, wonderful teacher, and he'll enlighten us on hemihemate arthroplasty. What about for the next talk, this one? Oh, okay. Tom, good to see you. Okay, thank you. I'm going to talk about an operation that's a little more fun than doing pins, because you get to futz around forever and a day, I have nothing to disclose. Again, this is very important that you know the limitations of this procedure. You can only do it when the palmar lip is destroyed. You need to have a dorsal cortex to accept the screws that are going to hold the graft in place. For those of you that haven't done it, what we're doing is taking the distal articular surface of the hemate, where it supports the fourth and the fifth metacarpals, and flipping that around and turning it into the base of the middle phalanx. That prevents the joint from hinging and allows it to glide around the head of the proximal phalanx again. Hill Hastings taught me this technique. I'd like to thank him for that. Again, this is the type of fracture that it's used for. Only when this palmar lip is destroyed, this is, I destroyed this in a cadaver, not clinically, but you've got to have an intact dorsal cortex. You need a wide exposure, and a typical Brunner incision pinches your exposure too much here, so I like to extend the Brunner with this extended mid-lateral line. You have to mobilize the neurovascular bundles, because you're going to dislocate this joint, and if you don't, you're going to stretch these neurovascular bundles and cause trouble. And then you have to get behind them and divide Cleland's ligaments, because you need a clear view of all of the collateral ligaments, so you really need to mobilize this. You can raise a flap of the flexor tendon sheath between the A2 and the A4 pulleys. We're going to use that during closure to protect the repair, and then drop down into the joint between the accessory collateral ligament and the palmar plate, and especially in a chronic case, that's sometimes harder to find the joint than you think. Once you're sure you know where you are, then start to remove the palmar plate from the fracture fragments. I like to leave the fracture fragments impacted into the bone, because they're oftentimes useful for supporting the graft, and sometimes you get in there and find out you can put the fracture fragments back together again, so you can do an open reduction internal fixation and not have to do the graft. Here are the collateral ligaments, and you can see, because we've divided Cleland's ligaments, we can see all the way around. Divide your collateral ligaments in the distal third, and make sure that you get all of these fibers divided, otherwise you're not going to be able to get this joint dislocated. You have to do both the radial and the ulnar side, we're just showing one here. Leave a stump of the collateral ligament, so you can reattach the palmar plate and your collateral ligaments, and then you get to dislocate the joint. You pull the flexor tendons aside, sometimes it's necessary to release a little bit of the superficialis insertion, and with a little futzing around, you get a great view of the base of the middle phalanx. So at this point, you want to measure your defect, and you end up doing a little bit of estimating here, even though it looks very exact. You have to estimate a little bit how much you need in the dorsal palmar plane, and you've got to make it big enough longitudinally to accept screws. You can usually palpate the CMC joint of the fourth and fifth fingers. You don't have to use a C-arm, but if you're in doubt, bring the C-arm in, and make the incision two centimeters proximal. I didn't do this in this demonstration, and we struggled. Open up your capsular flaps, that exposes the CMC joint, and you can see the fifth metacarpal, and the fourth metacarpal, and the hamates right here, and so if you close your eyes and imagine, that does look a little bit like the base of the middle phalanx. You want to mark your graft, and again, we like to say this is to the millimeter precise, but you end up doing a little bit of guessing here, and you have to preserve these columns. This lateral column is what's going to be supporting the fifth metacarpal. This medial column is what's going to be supporting the fourth. Make sure you mark your graft outside of where you've measured it, because the graft is going to shrink when you start drilling holes and using the saw. I like to pre-drill the margins of the graft with the K-wire, probably not necessary, but it just gives me an extra minute or two to make sure that we're making the graft the proper size. Distract the base of the metacarpals with a freer elevator, and also distract the joints so you can see how far down you're going to go with this saw. You want to make the graft big enough, but not so big that you get all the way through the hamate. So you get all the way around the graft, now you've got to get that graft out of there, and this is where it becomes tricky. You can't usually go from the articular surface in, so you have to make a back cut in the cortex of the hamate to allow you to get under this graft and get it out of there. The freer elevator's in the mid-carpal joint, and we're going to go ahead and remove this cortex. Then we're going to take a little bit of the cancellous bone out so that we have access to the deep surface of this graft. And this is where I get nervous. This is usually where I look at the fellow and go, let me show you something here, and take the instruments away for a minute. I like to pre-drill the subchondral bone at the articular surface to weaken it a little bit, and then you come after it with a sharp curved osteotome, and be patient. If you shatter this graft, then you're going to have to go to plan B, which is a palmar arthroplasty or something of that nature. So be careful. Use a small mallet, take your time, gently get this graft out so you don't create a case-ending disaster at this point. If all goes well, you're going to end up with a really nice graft which has good articular surface and has enough bone dorsally that you can accept screws and get it in place. Go ahead and close that wound up, and then you're going to go, you can see that this is stable. The fifth metacarpal is stable, the fourth metacarpal is stable, even though we've taken out a lot of the hamate. Now you start your footsie carpentry work, and this is where when your total hip surgeons come in and look at what you're doing, they're going to laugh at you for spending 20 minutes getting this perfectly fitted into this defect. Take a little bit of bone off, and then put the graft back in there and see where it's not riding properly, and then you go back and foots some more. In small grafts, you're going to end up doing all the tailoring with a ranger, and you just have to be real gentle, take off a millimeter here, a millimeter there. If you've got a really big finger, like a middle finger, you can use a saw to tailor the base of where the graft is going to sit and the graft itself, but it seems like I'm doing these most of the time in a small finger, and I never get that option. Put your graft in, put a K-wire in to hold it in place, and make sure you get this graft in properly. You must recreate the cup-shaped geometry of the base of the middle phalanx. If you put the graft in too flat, which is easy to do, this joint is going to remain unstable, and the middle phalanx is going to ride up over the head of the proximal phalanx. You're going to have a prominence here, where the graft is going to be more prominent than the base of the middle phalanx, but that's okay. You have to accept that to get this cup-shaped geometry recreated. You can see here, we've recreated the cup, so that the middle phalanx will hold on to the head of the proximal phalanx. You want to check that on C-arm, and make sure you're okay, and then it just becomes a standard technique of putting some screws in. You want to get at least two screws in. If you can get three, that's great. Usually I try and use 1.5 millimeter screws. Sometimes they need to have a little smaller screw, but whatever you have, you want it stable enough that you can move this joint right away. Here's our articular surface, because we hand-tailored it, it's a little ratty, but if we look at a lateral view, you can see that we've recreated the cup-shaped geometry, so that that middle phalanx is going to hold on to the head of the proximal phalanx. Test your stability, and look at it under C-arm, and then close your palmar plate to the stump of the collateral ligament. You can close the collateral ligament back up to that stump also, and then bring that flap of flexor tendon sheath underneath the flexor tendons, so that you've got a gliding surface between your graft and the tendons, and you're all done. You've got to close the skin. When you look at the final x-ray, you'll see here that my screw's too long in this cadaver. I wouldn't have accepted that in the patient, but we've recreated a nice cup of the base of the middle phalanx. The articular surface of the hamate is thicker than the middle phalanx, so it looks like there's a step-off, but you know it's not there, and that prominence is there. Thank you very much.

hemihamate arthroplasty

hand fractures

surgical procedure

distal articular surface

hamate bone