All right guys, so it's five o'clock. We'll get started here some of the panelists. I think are still on the way in So my name is Joe Gill. I'm from Brown University And I'll be kicking off this session here introducing the speakers And like I said some of them will be making their way in for the later talks So we have a Trey Crisco from Brown here talking about biomechanics here. We have Guillaume Hertzberg from France He'll give us experience with total wrist. Dr. Rizzo will be stepping in as well and dr. Weiss from Brown So I'll just get started here talking about a little bit of history of arthritis and total wrist arthroplasty I think that's the best way To get a feel for how the indications for this type of procedures and why the indications are expanding What's the motivation for it? Sorry so to begin with a little history we all know that the wrist kinematics are complex dependent on the interaction between The bones and ligaments and any type of disruption in this in this interaction or any type of trauma Could alter this resulting in arthritis Incidence of arthritis in the United States is about thirteen point six percent for this one study Arthritis occurs as a result of a variety of insults to the cartilage Including trauma and other processes which we'll get into in a second here that result in abnormal joint forces That ultimately result in degenerative changes So this is again post-traumatic such as slack wrist snack wrist avascular crosses of the lunate resulting in keen box disease and inflammatory arthropathy Arthropathies could also result in this and finally idiopathic osteoarthritis So treatment for wrist arthritis. We all know begins with conservative management including immobilization and anti-inflammatory medications A lot of these patients already tried the over-the-counter stuff so typically I what I use is meloxicam and naproxen and others are equally effective and Steroid injections is what typically we resort to once patients show up and try the Alternatives and the problem with these options is that a lot of them are temporary and patients become Relying on them and they're not as effective and they often seek out surgical solutions so to begin with a More conservative surgical option of wrist innervation. I think there's interest in this because it's relatively Minimally invasive a quick recovery and it does provide at least short-term pain relief So I think it's a reasonable option for the patient who can't take that time out of work For a fusion or an arthroplasty or something along that line This is just a systematic review of six studies looking at 135 patients After a wrist innervation and basically demonstrating again high satisfaction and pain relief up to 90% But the problem is at a short one-year follow-up, you know, a quarter of these patients are looking for more surgical options This is a review out of Mayo Clinic looking at their experience with the AI and PIN direct to me and again Demonstrating an improvement in the male risk score. However at two years again about a third of the patients required more surgical intervention So again, it's it may be a reasonable option for that patient who? Can't commit to a longer recovery time. But again, it won't be durable and that's important to relay that to the patient As far as The under with wrist innervation, I think you had good short short-term results But the problem with recurrent with recurrence of pain and progression of arthritis So the next option to the more traditional option for pancorp arthritis that's failed conservative management would be wrist arthrodesis Again first reported in 1910 by Eli for tuberculosis And again, I think the recent all the recent reviews demonstrate excellent pain relief with with high fusion rates So I with at least more recent technology However patients do despite having a Lot of times saying they would proceed with the surgery again do I would wish that have some more motion to do some of their? functions so this is just a systematic review of 45 studies looking at 1700 wrists Demonstrating again this improvement in pain and high satisfaction, but again high complication rate Relatively high complication with this procedure. So again, it's not not benign But again, it is the go-to kind of more reliable procedure for that young laborer who could not tolerate an implant So this is a review again of wrist arthrodesis Again demonstrating the issues again with it is that it is a very reliable procedure and takes away the pain But the patients oftentimes can't do some of their tasks with that fused wrist So again to review wrist arthrodesis, you know excellent pain relief It's a very reliable procedure with high fusion rates with the existing technology But a complaint about from patients is that they can't do all their functions with the look with the fused wrist so To the next option is a total wrist arthroplasty, which is why we're here to discuss today against an evolving technique the Goals are to improve pain and preserve function Patients have high satisfaction With with this procedure because it does take away their pain preserving some motion Some some studies would say that it could be a cost-effective option in some situations But it is associated with a high complication rate Which is reduced being reduced with the more more recent generations, but it is a current still a problem with this technique So again comparison of patients who underwent arthrodesis with total wrists in this review Demonstrated that both were satisfied, but the patients with the total wrist arthroplasty trended toward better function This is another comparison between Arthrodesis and total wrist arthroplasty Demonstrating similar quickdash, but again, it's a similar functional limitations demonstrated in the arthrodesis patients that the patients with the arthroplasties Were more satisfied with their function So just a history of total wrist arthroplasty So how we got to today and again, this is this is an important It's important to understand this portion of it because it'll help you understand why the indications are or what why we could expand those indications So there's just a quick review of the wrist resection arthroplasty that was first done in 1762 And then it was 130 years later where the first implant came out by the mostly's Gluck who? Tried to use ivory ball and socket implant with forks on the ends of the implant for tuberculosis wrist and this was complicated by a draining sinus More recent history with this implant is the first generation Swanson implant that was introduced in the 60s It's a double stem silicone hinge as we see in the fingers So they do they did use the metal grommets patient reported significant relief initially, but they're complicated with a very high complication rate with Implant failure and a high revision rate at six six years the second generation Implant was inspired by the total hip arthroplasty The arthroplasty technology that's coming out So similar designs were attempted at the wrist the first one designed in the 70s I was a ball and socket implant with a 33% reoperation rate I found a Mayo Clinic and a lot of the failure is attributed to miss implant misalignment loosening and issues with soft tissue balancing the next implant was the implant introduced by voles, which is a semi-constrained implant that He thought the wrist implant would be best semi-constrained because of the little stability that's there from the bones and With that implant they found again a high Complication rate at 44% with with a significant failure rate. So the third generation implants were beginning to adopt the Ellipsoid articulation trying to mimic the dart throws motion, which we which which was you know understood at that point as being the more accurate range representation of the range of motion the wrist And even with these third-generation implants the complications remain somewhat high lower than the prior implants But somewhat high still and these are reserved for primarily patients with rheumatoid arthritis So with these are the current four designs that are approved by the FDA And I think that there's a fifth one as well now coming out. There'll be more available across the United States and the what's unique to these designs is that they're designed to Maximize bone stock by minimizing cuts preserving the distal row the carpus by improving bone and growth by making the implants porous coated and improving fixation with longer screws This is a review of dr. Weiss's series 69 patients who? He followed over approximately nine year follow-up mean follow-up. He and he reported a 8% Loosening rate. Otherwise patients were satisfied with their pain score and our promotion this is a review of the fourth-generation implants kind of what's out there looking at these at the Complication rates ranging from 8% to 30% and with this implant I think you we see that the indications have expanded because I think it's the Longevity of it has increased so people have started use it for the post-traumatic osteoarthritis It primaries are osteoarthritis patients given that's a long longer longevity So it's not not as much concern about the relatively younger patients It's also used for Patients who had prior wrist surgeries like PRC or four-corner fusion or even patients who had a prior wrist arthrodesis for example on both Sides and wants a motion you could convert it with to total wrist arthroplasty with the more recent implants And again a revision arthroplasty to another implant is a more Reliable technique now because it does take less bone So if it does fail you could go back and cement a new implant in So issues with current wrists are you know they they did reduce, but they have not eliminated Complications because they are not perfect all the improvements so far are mostly empiric and they still have to be studied over the next couple decades to actually see if they prove to be as effective as their hope as we hope they are and Again, it is hypothesized that implants that mimic normal joint motion or joint kinematics will reduce complications and a lot of the more Recent fifth generations, so to say would be it would be Fissionary implants it would be trying to get to that more more more accurate representation of kinematics to reduce complications So next speaker here will be Dr.. DeTrey Crisco from Brown he'll talk to us about the biomechanics, and how the current implants are improved because of them Thanks, Joe. So, I'm going to talk a little bit about the biomechanics of some of our current studies that are ongoing right now that we just finished, the conflict of interest statement. So, TWA lags substantially behind total knees, total hips, total shoulders, and this is my biomechanical perspective on why, and perhaps the approach that we're taking to try and solve that problem. So, this is from our in vivo carpal kinematic study, and one simple explanation is the wrist is far more complicated than the hip and the knee, but that's really what we're building upon is the history of hip and knee implants, so we have ways to go. Certainly, the complexity is a big challenge. Wrist fusion, as Joe mentioned, is an alternative for low-demand patients, but as patients also get younger and older patients have higher demands that are now seeking motion-preserving treatments, there's more of an interest in total wrist arthroplasty. So, TWAs are about two orders of magnitude less than total hips, and that drives a lot of the, not only the commercial market, but also the research, too. There's, you know, less of a big pocket of money. The patient registries are extremely limited on total wrists. The retrievals are extremely limited. I think there's only one out there that I know of, and then preclinical testing is also extremely limited. You can buy knee simulators, hip simulators, but there's not one currently available for the total wrist. The FDA, for HEMIs, for example, have requested PMAs for radial HEMI. Also, if you come up with a novel design to prevent the breakout through the metacarpals, that's also going to require PMA. The big problem there is the market size really does not support PMA studies, so you're really taking incremental steps with the FDA. Fred Warner and Walter Short of ASTM are working up in New York, are working with ASTM to develop a standard for total wrists, but right now it's mostly descriptive. There's no preclinical testing guidance right now for manufacturers for total wrists. Now how do we test total wrists? So this is ongoing. There have been some tests, but we have robotic tests where you drive it with force. You can also measure the strains within the implants, or as Dr. Warner's done for years, you could also drive it through muscle simulations. So these are all ways that tests have been performed, but again, there's no standardized testing for total wrist arthroplasty devices. So our approach to try and get at this problem is to develop an understanding of in vivo biomechanics of total wrist arthroplasty. So an overview of our approach is we're using biplane videography, which is essentially souped up fluoros with high resolution image capture screens and video cameras. With a CT scan or a 3D model, you can track the motion of any object in 3D space from these video fluoroscopy units. And I'll tell you about the study that we've done. We've looked at the kinematics of healthy individuals as well as total wrist arthroplasties. We've measured the center rotation, trying to get an understanding of how they function in vivo, along with alignment of the components and the contact patterns of the carpal and the radial components. So in this study, it's feasibility slash pilot study, because we only have six TWA patients. Of note, only one implant was studied, and that was the FREEDOM. We had 10 healthy controls. CT scans were performed of the wrist, and we didn't have the manufacturer's CAD models, so we used a laser scanner to develop the models for the implant themselves. We tracked the metacarpal, capitate, and radius in the healthy individuals and the replaced wrists. We also tracked the resected capitate, the carpal component, and the radial component, along with the resected radius. So these are tasks that we examined, pitcher pouring, hammering, and then three range of motion tasks, flexion extension, range of motion, circumduction. So essentially what we're doing is we've got a frame, which is in the blue, from the videoradiography, and then we take the CT scan and we generate a synthetic X-ray, a digital reconstructive radiograph. And once we have that, we try and overlay them and align them. We enhance the images, and then once it's aligned in both videoradiography images, we then get the three-dimensional coordinates. We've done accuracy study using cadavers, and we can track the motion of the implants as well as the healthy wrist within about one degree and one millimeter. So we're able to calculate center of contact, which is estimated based upon the distance between the carpal component and the radial component. We can't measure pressure yet. We are able to estimate the center of contact and the proximity mapping. Another component of our analysis was to look at alignment. So we looked at the third metacarpal, long axis of third metacarpal, and the radius relative to the stem of the carpal component and the stem of the radial component in both lateral and PA films. And then we did the same thing on CTs. We used CT as the gold standard for measuring alignment. Again, we used the long axis, the radius, third metacarpal, and then the axis of the stem on the radial component and the stem on the carpal component. The results of the study on the right is all the motions combined together. And as we expected, the control cohort, healthy, had an elliptical motion aligned along the ulnar flexion radial extension of the darthrow's path. Also, as expected, the TWA cohort had less motion, but what was interesting is that there are these sort of an ellipse, especially the variability. You see these prominences in extension, ulnar deviation, and ulnar flexion. We're not sure right now what the mechanism behind that is, but we're hypothesizing that's due to elliptical nature. So you're really rotating primarily about the major axis and the minor axis, which would be flexion extension and radial deviation. Another factor that we looked at, another kinematic measure was center of rotation. So if you have a elliptical object, its center of curvature also can dictate its center of rotation. So in a radial view, you see the center of rotation would be in the center of curvature, which is the minor axis. And in an AP view or volar view, you can see the center of curvature, which would be radial deviation, is defined by the curvature of the carpal component along its major axis. So this is the data we collected for all positions and all tasks of the individuals. On the right is the healthy wrist. What we did was we took the circumduction and all the motions together and we splayed them out on the x-axis. So if you run along the x-axis, you're running along a circumduction motion from extension to radial deviation, flexion, ulnar, and extension. And as we looked at those different directions, we plotted the location of the center of rotation for the healthy individuals, and then we did the same for the TWA replaced. And what you see is the healthy individuals, the center of rotation moves approximately distally, approximately 10 to 15 millimeters, but then replaced as we expected or as we hypothesized based upon those radius of curvature, there was a much bigger swing from about 2 millimeters to 25 millimeters, almost 27 millimeters of shift in the radial and the proximal distal location of the center of rotation. These are the patterns of contact. So this is an exploded view. You're looking at the inferior surface of the carpal component on the top row and the articular surface of the radial component on the lower row. The big dots are the average and the 95% confidence level are the smaller dots. You can see the flexion extension as it moves from volar to dorsal and the same on the radial component. Of note, in radial deviation, you can see a large tracking of the contact area in the carpal component, a fairly small tracking on the radial component. Circumduction, what I'm showing here, each colored circle is the path, the center of contact for each individual subject of these seven subjects, both on the circumduction, I'm sorry, on the carpal component and the radial component. The take home here is that on the carpal component, the center of contact is heavily biased towards the radial side and on the radial component, it's heavily biased towards the ulnar side and that's fairly consistent across all motions. If we looked at the agreement between the x-ray and the CT scan, again using CT scans as the gold standard, the radial component, there was very good agreement from the x-ray to the CT scan. So we can use x-rays to get accurate measurements of component alignment. For the carpal component, it was not as accurate but it's still quite reasonable using x-rays. Of note is we also examined across these six subjects the tilt of the radial component relative to the long axis of the radius. So these six points here are the six subjects and the dorsal tilt to volar tilt was computed and we found there was, we measured about 15 degrees range of dorsal tilt to volar tilt across these six individuals. But of note, that 15 degrees of tilt corresponded to a 45 degree range of flexion extension. In radial ulnar deviation, again we saw the correspondence relationship between range of motion and the volar tilt of the radial component. So to summarize, the center of contact was not located in the geometric center of the components. In this frame here that we've frozen, you can see it basically radial contact for the carpal component and the ulnar center of contact for the radial component. The center rotations did differ significantly. They were more distal for radial ulnar deviation, somewhat more proximal for flexion extension, but the sum of those two resulted in a much greater proximal distal shift of the center rotation with TWA subjects. And again, we found that more volar tilt was associated with the large range of motion across these six subjects. The limitations of these studies are notable. We only had six subjects. It was a single implant design. We did not have any preoperative data and we studied these patients only at a single point in time. We did not calculate any impingements at this point in time. And the correlations we're showing are based upon this single data set. We don't know what effect the differences in the center rotation and alignment will have on the clinical outcomes of these patients over a long period of time. The next steps, we're very interested in the knee, for example. There's ongoing and continued debate on whether you align a total knee based upon the mechanical axis or the kinematic axis. We'd love to pursue this further in the total wrist. We're hoping to get as many surgeons as we can that are interested in participating. So if you're interested and any TWA implant that you've performed is eligible, if you've got pre-ops and recent radiographs, that would be required as well as outcome measures that you use to track. And if you're interested in participating in the study, you can email me or talk to Dr. Weiss or Dr. Wolf. Thank you. Good afternoon, and thank you for the invitation to talk about this very topic on rheumatoid arthritis, and I want to acknowledge my two co-authors. This is the outline, and thank you for sorting the rheumatoid arthritis compared to the osteoarthritis. These are not the same patients at all. The fusion is something that has been a winner. The good news is that we don't need a lot of motion, a lot of extension to make a wrist functional, and the other good news is that the designs are evolving to something smaller and more reliable after those complications. I'm going to talk about the remotion because this is the only one we know, and about the indications, we are talking about rheumatoid patients, so we have to remind that this is not only a surgeon's decision, that there are priorities, general priorities, and local priorities, and we don't have to consider only the wrist or the fingers, and even in the hand, there are priorities, as you can see here, but basically, it's good to begin with the wrist, going from the wrist to the digits. Radiologically, this is not enough to make a decision. We need something more, and this classification was very nice to define the stages. Of course, arthroplasty is not indicated in those osteoarthritic patients. They just need an alignment, and they are happy with that. There is nothing we can do, and here, there should be more difference between the 2 and 3A, and we propose that these are different stages. One is stable, the other one is unstable, and within the erosive group, these are the two groups, A and B, which are different in terms of indication. Volar subluxation hasn't been a contraindication in our experience. I'm going to talk later about this, as you can see here on the lateral x-rays, even if it was dislocated initially, and now some technical aspects. We all know the remotion. The axes have to be respected. They have a nice guidance technology, but this is for normal wrists, and they are not normal at all in rheumatoid arthritis, like in this case. We have to put them in the right direction and operate on being, I recommend that at the end of the hand, to have control of the rotation, and this is the technique and the reduction and the care to the extensor retinaculum, and we can have a very good correction. I don't know in terms of center of rotation, but at least the correction, the whole correction of the wrist is acceptable. The outcomes, my good friend Michel Bouxtas put together this remotion database, and the conclusion was that it was reliable. It was a breakthrough within the wrist arthroplasty evolution, but it was only clinical. Good implant survival at this time. If you start with a poor motion, you will end with a poor motion. There are exceptions. We are going to see this, and this was our conclusion at this time. However, we didn't look at the x-rays, so there were loosenings and periprosthetic osteolysis that we didn't understand well, so we went with Michel and Marion Burnier, who is in the room, and we very carefully, this was a tough work, to measure all the osteolysis and to describe this, and we found that, first of all, there wasn't any difference between the rheumatoids and non-rheumatoids, and number two, about 44% had periprosthetic osteolysis, which was a huge proportion, and this was something new that we learned. From our series in Lyon, first of all, we didn't push the indications of arthroplasty. You see, we did a lot of fusions during the period. Number two, 12% revisions in rheumatoids, a good improvement, and these 30 degrees of extension that changed the life of the patient because they can make a fist. Some examples, this one, a bilateral TWA in a young lady, very rewarding. This was interesting because there wasn't any ECU. We discovered that, and we grafted this. Then we put four MPs, and this is the final result with a very functional wrist and digits as well, and an active ulnar inclination. If I can show this, the grafted tendon was working. This patient, Marco Rizzo, you remember we operated on this together. He was happy, but he had this major osteolysis, and really it's a big concern. Another one, osteolysis and fracture, so complications do exist. Another one, we made a mistake. We tried to get more motion, and we failed because she was stiff at the end, so this is like in the curve, so we had to convert her in a fusion in a better position. However, there are exceptions to that with this lady. Very interesting case. You see there is a complete volar dislocation of the carpus. She had carpal tunnel syndrome and a problem for the flexors, of course, so we put the x-rays in the right direction, and we are at the end of the hand operating on first dorsally to remove the ulnar head, then volarly, and you see the carpus dislocated, actually, volarly, and we preserved the capsule, of course, to close it at the end. This is the dorsal capsulotomy, and the sculpture of the wrist and to make a room for the implant, and again, I don't know about the center of rotation, but there is not a lot of room to get into this wrist. This is the carpal component, and then the provisional reduction. This is a stabilization of the ulna with the transosseous sutures and the combination of both, and a special care to the closure of the retinaculum and the management of the extensor compartments to get functional extensor compartments, if at all possible. This is the x-ray. My wrist was blocked for 25 years, around, and now, after this operation, with this arthroplasty, I can move it. So, this is an exception to the rule. She gains motion. This is unusual, but we have to know that. She's at 10 years now. Surprisingly, she didn't want anything to be done for her fingers, who are very poor, and this is how she's using it. She's a strange patient, but she's very happy. So, anyhow, this was an exception. Good, acceptable clinical results, but concerned with revisions and especially periprosthetic osteolysis. Now, what about the pyrocarbon? If there is osteolysis, there might be a room for the pyrocarbon, and this, again, this patient is interesting. Left was a 2A, stable. Right was a 2B, unstable. You saw the volar subluxation and the ulnar translation on the PA view. On the left side, we did a pyrocarbon, but we didn't dare to do that on the right side because of the subluxation, because the problem with the pyrocarbon is, of course, subluxation. So, these are the results. We did a fusion on the right side, a pyrocarbon on the left side, and I am sorry that the fusion is a little bit better in terms of function and clinical score, and this little video is interesting because she rides her own horses, and you see left the pyrocarbon with the motion, and we're going to see the strength soon, and I am sorry that the pyrocarbon side is only that, and the fusion is stronger, and she sent us this video, and you see right is the fusion, and this is how she uses it. I think it's very interesting to see this little movie, and left this pyrocarbon, so she combines both, and she seems to be happy with the combination of a fusion on one side and the pyrocarbon on the other side. I really don't dare putting a remotion implant in this type of patient now, knowing that we know about periprosthetic osteolysis. So, a quick discussion. This diagram is still valid. We added the x-ray because it's important, the 2A versus 2B, and of course we have to preserve motion, but we have to avoid complications by any means. Complications of the remotion are the osteolysis. We don't know exactly. Michel Buchstein has worked a lot about that. This morning we concluded that it was stress shielding, very likely, and the pyrocarbon can dislocate, so there is no perfect solution. This is a great opportunity to improve our implants by any means. Thank you very much. Thank you. You mean if I see osteolysis? We have only one case which fractures. Yes, you recommend that they don't do too heavy activities, of course. We grafted an epiphysis and it healed, but it's different. The fracture is a more proximal problem than the epiphysis. Michel was talking about that this morning, and he's tried it, and we've tried it too. We hope that it makes a difference. You do see osteolysis coming back, and Michel confirmed that he thought it didn't really help, so he probably has the biggest experience with that, I think. An interesting thing is that we have a large experience with the hemis in fractures. We have 30 cases in a series. There is no osteolysis at all in hemis. It's a radial component of the SBI or a new one. What's the cause of the osteolysis? We discussed that this morning, probably stress shielding, but we don't know exactly the reason. And Michel worked on that extensively. He concluded that it wasn't a wear, a polyethylene wear problem. If the osteolysis is mostly around the radial component, why would there not be stress shielding in the hamstrings? The osteolysis is both at the radial component and the carpal component. And maybe it's a rotation problem, I don't know. Do you have any answer? Marion, could you come to the mic, please, if you? Sorry, just Dr. Crisco, I should show nicely with you that there was a lot of motion of the center of rotation in this kind of arthroplasty, if I am not wrong. So I was wondering, maybe as this center of rotation is moving a lot compared to the normal center of rotation, it implies some forces onto the radius compared to the ME, because in the ME, we don't modify the center of rotation. So this could be an answer. Could you please come to the mic again? The big difference between the two techniques, because in the total wrist arthroplasty, we have a carpal component that force on all the plate, the radial plate. When you perform the HEMI, I perform also as shown this morning, I perform always a proximal rocarpectomy. And so we have only the capitate that stress on the radial, I think, I'm not sure, but I think this is one. So it's a different center of rotation. Yes, different center of rotation. So we have two experimental models. Yes, I think that one codes. May I please ask a question? I'm sorry for the... So important question or distinction, I put my hat on as a hip arthroplasty surgeon, I confess, in addition to a hand surgeon. Osteolysis without debris is not osteolysis, it's stress shielding. And so the confusion is, you call it osteolysis in the membrane, do you see polyethylene particulate debris or not? If not, probably it's not osteolysis and it is a stress shielding physical property. And the distinction is critically important to understand the failure. So which is it? You use the words stress shielding and osteolysis interchangeably, and I would ask you to differentiate and distinguish those two pathologic processes. Yes, sir. Thank you. Thank you. That's a very important remark, and actually it is stress shielding. So what do you call the... Atrophy. Atrophy. Okay. Atrophy is not osteolysis. Osteolysis indicates polyethylene. Okay. There's no polyethylene in the membrane. No. No, Michel gave evidence about it. So when you have around the stem of an ulnar implant, which is a hemi, when you have shortening of the bone around the stem of the collar, you call this atrophy? It's a question. Yes. Okay. In absence of polyethylene debris, is a stress shielding mechanical process not osteolysis? Okay. So we hypothesize that it is stress shielding and atrophy, to answer your question. All right. Thank you. So we'll move to Dr. Weiss. And for the sake of time, we'll go to Dr. Rizzo right after that instead of the discussion about the osteoporosis and the DREJ. This is going to be fun, because I have a different opinion than the one that was just expressed about polyethylene and metalosis. So we'll see. So I'm going to talk about osteoarthritis and post-traumatic arthritis with total wrist arthroplasty. So it is a different. These are my disclosures. In the United States, at least, and I can't really speak to the European experience except anecdotal discussions with my European friends, wrist arthroplasty is making slow, steady gains over arthrodesis. I think people who are comfortable with the technique are starting to use it quite a bit more. Certainly, patients, as we already noted, prefer wrist arthroplasties over fusions, although we know fusions last forever, essentially. And now in the United States, rheumatoid arthroplasty is probably less than 10% to 15% of the patients I do. I do about one arthroplasty every two to two and a half weeks. And most of them are osteoarthritis or post-traumatic. And so you also got to watch out for the selection criteria, because if you put this in somebody with very high demand, you're probably asking for trouble. There are a lot of, I think there are a lot of indications. You can see these pancarpal arthritis, like primary OA, bad malunions, hemiarthroplasties with an implant that fail, unknown patterns, which we really don't know why they happen, bad slack or snack wrist, and obviously PRCs that fail over time. There's some relative contraindications. These go along, kind of similar to the rheumatoid patients. If they have very poor stabilization, bone stock, previous infection, motor deformities, you're probably better off with a fusion. I think the ideal patient, certainly the ideal patient's bilateral disease and already has a contralateral fusion. I don't like to fuse bilaterally. They've got relatively good alignment and motion. I think this is a little less important and less frequent in osteoarthritic or post-traumatic patients than it is in rheumatoid patients, which have an inherent soft tissue malalignment. And then what's the age and physiology of the patient? I think in my practice right now, if it's above 55 years of age, medium activity, I don't have a problem doing total wrist arthroplasty. And I balance the age and their activity level either above or below that threshold. Obviously, the alternatives are well known and have served us extremely well. And I think when you're counseling with patients, you always got to bring these up. And patients may decide that they want one of these, especially in one hand, that may be their dominant hand going forward. We know the history. We've talked about this. It's gone through several iterations, which was interesting with the biaxial wrist, which Bob Beckenbald worked on. The problem was always the carpal component would loosen, but the implant would very rarely dislocate. Whereas with Jay Menon, which was the universal one, the carpal component was quite stable, but the implant would tend to dislocate. And that was partly due to the radial component design. Again, further improvements with the universal two freedom, the remotion that we've heard about, and then to some degree, the Maestro, which is now not on the market anymore for a variety of reasons, and they have a pretty good track record, 15, 20 year track record at this point. In 2020, there were two new implants, at least in the United States that came out. One wrist motion implant from Onika, and the second Akinimax from Extremity Medical. And these took a different track. And I designed the Onika, which is the one on the bottom on the left. And Trey and Scott Wolf designed the Akinimax. But basically the idea behind that, because Trey, Scott, and I worked on these biomechanics projects that you thought about, that you heard about, the premises for design of both independently came out with essentially the same conclusion. I'll talk about the poly, because I think the poly is a big problem. I don't agree that there's no poly to wear debris. There'll be an article coming out in JBJS about the analysis of retrieved membrane, as Vinny pointed out, in revision total wrist arthroplasty, both with metal debris and polyethylene debris. And I'll discuss a little bit about the difference, I think, with stable implant and a non-stable implant, where it's circumferentially loose, or if the stem is fixed proximally and it's osteolysis distally. They're two different, they can be two different things. In the hip, we know that polyethylene debris in soft tissue in revisions is a big problem. So is metal particles. They don't get phagocytosed by macrophages. They get degranulation, and they get erosion of the bone. Lane Smith, who's a PhD at Stanford, Bill Maloney, who's a friend of mine, who's a hip surgeon, I use their technique to do an analysis of these membranes, and that's what's coming out. I don't want to spoil it, but that's what's coming out. I do think that wear particles play a significant role in this. I think stress shielding does as well, but wear particles are extremely important. So these new designs, to the thing we were discussing about the center of rotation, moving up and down in the current designs, and I think Marion just brought that up, that that's a big problem, because it's constantly pounding back and forth. Part of your wrist wants to have the center of rotation at the distal capitate, and part of your wrist wants to have the center of rotation at the distal radius, and they don't match each other, so it's a non-coherent match going forward. And so, by flipping the design of the carpal articulation, you can actually move that center of rotation closer to the distal radius, which makes it have less of a sinusoidal wave. And also, putting a smaller degree of polyethylene that's metal-backed. We know from the knee literature that metal-backed polyethylene, on the whole, everything equal, lasts much longer than non-metal-backed polyethylene, because of cold flow and other parameters. So I think having metal-backed polyethylene will, over time, do us a service. There are a couple tricks, and I saw this in one of the earlier slides. Whenever you put these in, you gotta remember that the distal radius is not always where you want the center of the radial component to be. And so it's very important to have the pin, the main pin that you're using for your radial component, should be center-center on the shaft. Don't look at, necessarily, the distal radius, what that looks like, because sometimes the pin does not look like it's in the right spot, but it is in the right spot. And if you're off with that, and you're pounding in a radial component, you can break the ulnar cortex of the distal radius. I've seen that happen. I would suggest you don't max out sizing. These are just things that I've learned by pain. Don't max out sizing. If you're in between a small and a medium, I put in a small. If I'm in between a medium and a large, I put in a medium. Why, because I wanna save bone stock. In case there's a revision down the road, or something else needs to be done, I want more bone present during that revision than I would have if I tried to maximize the implant. I think these do get very well fixed, especially the radial component, and so I don't worry about being slightly undersized. If you have a failed PRC, it's very hard to get a total wrist replacement in. It's a very tight gap. You've already lost some of the bone on the carpal side. If you're using an implant like these two new implants, which don't take a lot of radius off, the SBI doesn't take a ton of radius off, the Freedom does take a lot of radius off with a saw. You don't have that much room to work with on the radial component, and if you're doing a osteoarthritis patient, usually, and the DRUJ is not a problem, you have a distal ulnar there, so you can't take off too much radius. You're gonna have an ulnar impaction problem. In a rheumatoid, tend to have a DERA procedure or something like that along with it, so it's not as big an issue. You can take more radius. So when you're doing, in a failed PRC, you're gonna take more carpal bone to get your implant in, to get the space so that you can get the implant in, because you can't take more on the radius side. So that becomes a challenge, because these central pegs, you don't really wanna see it in the third CMC joint, but if you have to do it, you have to do it, because you'd rather get good fixation. That's why the two-screw technique, which the FDA, it's the only, if you don't have two screws in the central stem, you can't get an implant approved in the United States, and I don't think that's gonna change for quite some time. And you want, I think you want the radial component to be floating above the TFCC. I don't think you want it anywhere near the distal ulnar or the TFCC in these osteoarthritic or post-traumatic patients. So I think this is what it should look like. So it should look like there's a space underneath the ulnar part of the radial component that allows a lot of space between the TFCC and the TFCC attachment and the distal ulnar. You do not want that pushing down on the distal ulnar itself. You wanna have the ulnar screw short. I think it's better not to have it in the mobile fourth and fifth CMC joint, so because these patients are gonna use their hands and those joints are moving, so try to keep it out of there. Obviously, the index finger is a very stable CMC joint. You just screw goes way, way across that and that'll provide some additional fixation. Here's just- Go. So this is after- Notice something on this guy's range of motion. Yeah, and then like this. Excellent, perfect. So he's about- Go. Oops, sorry. He's about four months out from his total wrist. His motion is in the, he does dart throwers motion, no problem, and I always had a problem with, I use the universal- Universal 2 and the Freedom, that was my implant of choice until these new designs, and it was very orthogonal, very extension flexion, radial deviation, and radial deviation was always tough. When you can get an implant that allows you to get out of that plane of motion, it also decreases the forces and the stresses on that implant going forward. So I think as the designs evolve over time, and there are going to be newer ones beyond these, we're going to start to see these implants be able to mimic the normal range of motion going forward, and that will decrease the stresses and decrease the wear parameters. So outcomes, I've done 19 so far of this new implant, 12 degenerative, 3 post fracture, 3 post PRC1 complex, very stable, I don't cast them anymore, I just use a splint. Only a DERA in one case that had DRUJ, DJD, I don't do it otherwise. Don't over tighten the capsule repair, you want it to move. These are done as an outpatient in the ASC, they have no drains, they go home the same day. A supraclavicular block, and we haven't really had, pain has not been an issue. Here's a case that was sent to me, a patient that has had multiple procedures in California and in Philadelphia, had a hemicap replacement, had ulnar shortening, had a toe implant put in the distal radius with multiple anchors to try to prevent this ulnar translation. Obviously it failed, and we basically took all this out, and it was a narrow working gap but revised it to a wrist implant, and the patient is pretty happy. We worry in these patients because there's so much initial destruction that maybe a fusion would be a better option, but in some patients they don't want a fusion and they won't tolerate that as an outcome. Here's just three papers that we published on, it was already quoted, one of them. The outcomes that we had at nine years has been replicated and there have been some other papers before ours, so you can really expect probably a 10-15 year survival rate of 75-78%. The papers generally are in that category. So the current implants work quite well, and so I think what we're doing is we're refining over time. I thought I had a picture in here of, I just want to talk about the poly stuff, because that seems to be pretty controversial, and I'll give you my opinion. When you see a radial component, and the stem, the proximal stem is well fixed, and then you see this big lysis, and this morning's lecture I showed a picture of that big, big lytic thing all around there, I can almost promise you that that's particle debris, okay? That's not all just stress shielding. And if you see one that has complete lysis around it, and the implant, the radial component is moving like this, you know, or the screw has a windshield washer look that's in the index finger, you know, that's, it's not, it's getting that windshield washer partly because it's moving, it's unstable, it's loose, but it's also got particulate debris. And I think some of that we'll have to see with a little bit more studies, what the real answer is and the ratio between those two, but I really do feel that particle debris is an issue. And I think the fact that it happens in hips and knees, for those of you that do those procedures and it happens a lot in those cases, you know, massive osteolysis in the acetabulum, to think that it doesn't happen in a metal and plastic wrist I think is not likely, so thank you very much. Thank you. All right. Dr. Rizzo, last one up here. Thank you for everyone's persistence here tonight. Thanks, Joe. Thanks for the invitation. This is really provocative and, and, you know, it's, it's, it's, it's, it's, it's, it's, it's, I don't, I have to double-check. Ben, when the hip and knee docs do it, I mean, I'm assuming he followed a protocol like the hip and knee folks when they look at osteolysis, but I got to get an answer for you on that one. But I guess the verdict is still out. The reality is that you'll see stuff like this, and what do you do with it? And there's different types of modes of failure. You have proximal component failure like the one I'm showing. You have distal component failures like this one. And you have miscellaneous, whether it be dislocation or subsidence. In this patient on the left, I had to do Adara after their surgery because the radial component just kept subsiding. Sometimes you'll see significant, this is a rheumatoid patient in the lower photo of revising and doing a synovectomy. A couple case examples. This is a 55-year-old male who was rheumatoid and underwent a biax wrist. This is eight years after with pain, ultimately graduated. In this case, we thought we could graduate to an arthroplasty with a newer generation implant. You'll see that when we do this procedure, though, that we take a lot of carpus. And thankfully, it felt pretty stable at the time of surgery. But there isn't a whole lot of carpus left, and the screws are going into the second and fourth metacarpals as well as the peg going into the third metacarpal and supplemented also with some cement. This is three months post-revision. This is three years post-revision. You're starting to see some concerning bone loss, lucencies, if you will. It gets worse five years post-op. Sorry. Six years post-op. And ultimately, 10 years post-op. So if we look at this case example, we're trying to figure out what is causing this, right? What is causing it? I mean, my intention was not to focus on this, but since we're talking about osteolysis, maybe it's a good topic for discussion. I think we got spot welds here, right? So very likely, this is well-fixed distally. So maybe it's a component of both, maybe. But the patient's happy, 10 years after revision. So I guess I'll take it. You see the motion with flexion is a bit limited, but extension is quite good, and we bought some extra time. But the data on revision outcomes is not, first of all, there's not much. And basically, the same conclusions are basically obtained. You know, Fisher, out of Kurt Peterson's group in Sweden, looked at their revision series, and they found that they had a 25% failure rate of revisions. This is 16 cases. For those of you who don't know Kurt Peterson, he has done hundreds of arthroplasties. So just the fact that there's only 16 that were candidates for revision suggests that fusion is usually the typical option, as Guillaume mentioned this morning. And you can see that the re-operation rates were substantial. But they did say that revision arthroplasty is a valid motion. Revision is a valid option, and despite the fact that 25% have additional surgery needs. We looked at our Mayo experience. Eric Wagner helped us look at this, and we found a significant rate of complications in revision surgeries, usually for distal loosening. Loosening was the main problem in terms of these failures, and we cautioned in advising the patient that these are associated with a high rate of complications, and ultimately leading to the nuclear option. But you can also have proximal component failure. This is another case. And you can see here at five years post-op, at this point in time, she's really not that asymptomatic. That's the unfortunate thing about some of these loosenings, is that they don't have symptoms. But she ultimately became symptomatic at eight years post-op, and in this case, her distal component was well-fixed, so I was hoping we could just revise the proximal component. And you can see the poly in this. I mean, you could argue maybe there's a little bit of wear here, you know. But it didn't look super bad, you know. And the implant was hard as hell to get out, as they usually are. I use a femoral head for bone grafting, and I used a custom implant that I was able to get from Stryker. And you can see that intraoperatively, it's pretty stable. And here she is at six months post-revision. I fractured her styloid, but it doesn't seem to be something that has proven to be clinically super relevant for her. She's four years post-op, and she's pretty happy with her motion and her function. But the reality is, most of the patients are like this one. This is a woman who had rheumatoid arthritis and a failed total wrist. And your options are basically fusion, and most of these need to be fused. Implants are not always super easy. You have a significant bone defect, and again, getting the implants out is not easy. I use the femoral head a lot. I lean on it a lot. And sometimes I use it as a structural graft, tricortical, or sometimes as just the cancellous. And with locking plate technology, I agree with Brian Adams' recent study. Our initial results when we were using Steinman pins and non-locking technology, the fusion rates were about 55%. But now with locking technology, we're able to get better fusion rates, largely maybe because I'm getting better at this, too. But I feel pretty confident that I can get a successful fusion after a failed arthroplasty. And she had turned out to be quite functional and happy. This is that study we published in 2011. We're looking into our new revised series on this and hope to publish it soon. And this is Brian's experience with a 90% success or 95% fusion rate. I'm going to skip this part here because I think we're out of time. This is a case of a DRUJ that failed, and I won't belabor it. So in summary, I say that these failed risks are a challenge, and it's important if you're going to embark on this surgery to counsel the patients that they can fail. And when they fail, they're complicated, and usually fusion is the only option. Oftentimes patients are so adamant that they want to preserve motion that you're inclined to want to offer them this. But I often will tell them this is stage one of a stage two endeavor. We may buy you some time, but the fusion is likely be or be accepting of the fact that a fusion will be necessary at some point in your life, especially if they're young. You know, the radial component failures, I think, are more amenable to revision because you have more bone to work with. The distal component failures are trickier. And more often than not, as I mentioned, fusion is really the only option. Thank you. You know, the x-ray you showed that had the spot weld of the two screws? The majority of the osteolysis, if you looked at the metacarpal, was at the stem, which is not fixed. There's no spot weld, has a third metacarpal that's not used to anything else. That hole, to me, screaming with particles. You know, I think all of us will have to work on this going forward. The one thing that they've shown in the hip and knee, it takes very little polyethylene wear. You can have almost no visual wear, both metal, you know, if you have metalosis. We see black synovium all the time. You look at the implant, the implant looks fine. It doesn't have defects anywhere. But obviously, all that metalosis is coming from somewhere. And the poly, when I take out the polys, usually it's the corners at the edge, that radial corner that's worn. But it probably only takes, I would think, a tenth of a millimeter, and you get millions of particles of polyethylene. So I think stress shielding does play a role. So it's going to be really interesting with everybody to kind of figure out what pattern makes what. And how much it correlates to each other. Thanks, Peter. Good topic. That is a good discussion. Ben? So, Mark, I'm going to go on record as agreeing with my good friend Peter, which doesn't happen very often. So we ought to note that. But I think there's something to be learned from the arthroplasty surgeons here. So those expanse eye lesions, 99 times out of 100, your very last x-ray, when you look at those distal screws, that's osteolysis with particles until proven otherwise. And when they expand out. And the interesting thing, and I don't know the answer to this at all, that is different in this population, is that the people who were rheumatoid disease have a very different immune system. And we know, what Peter was just mentioning, the degree of particulate debris does not necessarily correlate with the degree of osteolysis. There are some people that react to poly like there's no tomorrow. And we look at their inserts and there's hardly any identifiable wear and deterioration of the poly. And there are some people that have terrible poly wear and no lysis. And this population, you're selecting for the rheumatoids that we have over the years. And all I'm saying is, I think that's a wild card. And that's going to make it very unpredictable to understand. And there may well be a very different relationship between osteolysis as we currently understand it with respect to particulate poly. And what triggers the degree to which the autoimmune system or the immune system responds to that poly. That's a great point. I think it may well be a whole different dance. But I agree with Peter. Those expanse eye lesions are lytic and they're particularly driven for the most part. And I just look at the component on the radial side, I think Peter said it well. It's a bit like setting a tibial component in the middle of a metaphyseal bit of bone. And if there's no initial fixation, it just dissolves around it. And the ones that look like they've got spot wells have got more of a tight stem down below and they've got some initial fixation. But I'm going to bet that the rheumatoid component to this has a factor. Thanks, Ben. Sorry, Joe. I don't want to hog after a moderate. Peter, you mentioned, I love the design, but you mentioned erring on the smaller side. But your stems are big. They're sort of wide. Yeah. My radial stem is big. Yeah. And that's partly why I err on the small side. But I do it mainly because of bone preservation. I'm trying to think what's going to happen in 15 or 20 years down the road. If I'm going to operate on 55-year-olds, it's not like I'm going to just operate only on 70-year-olds or 80-year-olds. And you know, you could say, well, I'll be retired and they'll be making the box. That's where Joe comes in, right? You know, we've got to think about that down the road. And let's say it's stress shielding. It's not particulate debris. Yeah. Then you really want to have some bone left over, right? So I think we made this stem like that for a reason. But it does make it important to centralize it correctly because otherwise you can break out, right? But it also provides really good stability if you're going to have the flange off the radial component, right? Yeah. You're not really relying on that bony impact of the tray. Yeah. Scott? Scott? Yeah, the maestro used to have a concave polyproximal, but as Peter mentioned, it's no longer available. Yeah. Yeah, that's a good point. Well, I certainly think the surface area... I mean, technically you got more surface area of poly if you have it on the convex side, right? I mean, so certainly intuitively it would suggest that you're likely to have more polyware as a result, especially in the fringes like Peter's alluding to, because you got... The poly's moving. In the maestro, the poly was never moving. It was the metal moving on the poly. I bet you a donut that if we had it on the concave... If we had a concave poly, we'd be better off. The poly in the patella fares miserably, and that's the only place it's compact. And it's subjected to much more shear. The poly behaves better under compression with some translation, but a lot of shear on poly is a formula for failure when it's compact. You know, Kurt Peterson had a design that he worked on that had the poly. It was a metal. It was sort of like a mini maestro, but it was... He was using peak as well, which I'm not sure if that would be better. Yeah, go ahead. Peter's design and our design are poly on the concave side. Concave side. On the concave side. Nice. Metal-backed. I also think in the end it's going to be... Not as big a factor, but it's going to be a factor. Now, Peter, when I was in training, metal-backed poly on the knee was a bad idea. Yeah, if you look at the literature, that's not the... There were definitely some papers that said non-metal-backed poly did better than... Metal-backed, yeah. But if you look at the overall papers and the Cochran studies, metal-backed poly is more supported than non-metal-backed, especially for the cold flow. It makes sense to me. The distinction is that the poly that was metal-backed that failed was pre-metal-backed. Yeah, pre-radiation. So it failed miserably. It makes sense to me. If the poly's well-fixed to the metal, it's less... Sheer. On that side. Whereas when you put in a poly, it's going to move a little bit. Remember when we had PCA hips and knees? They had a batch of bad poly. Yeah. It destroyed... You know, the poly has changed, the technology has changed so much that it's not the same as when you read a paper from 25 years ago. It's not even the same material. Yep. Joe? We hijacked your discussion. Controversy! Controversy! Thank you. Thank you for a great discussion, guys.

total wrist arthroplasty

surgical procedure

wrist arthritis

indications

outcomes

complications

revision surgery

osteoarthritis

post-traumatic arthritis

implants

alignment