• LecturehallSubtalar Joint Arthroereisis
  • Lecture Transcript
  • TAPE STARTS – [00:00]


    Marie Williams: And now it's going to be great and I'm talking about subtalar joint arthroereising procedure. I actually did this lecture. I requested to do this lecture. Dr. [Shawn] [00:12] has the periarticular subluxation of the talus I think or something like that earlier this week when you first got here, but I wanted to do this lecture because it's very important to me. There was a couple statements made recently that this is a very poor procedure. And I thought, "Well, that doesn't make sense to me because I use it quite a bit and I get good results, never perfect, but I think it has its place." So that's why I'm doing this lecture.

    So that's basically, what is an arthroereisis? It's basically it comes from the Greek word arthron, meaning joint, and ereisis, meaning, a raising up, which makes kind of sense because what we're doing is we're raising up the talus with the little plug, so what we'll see. The [Kirby] [1:03] actually in podiatry today, which I really liked, is that the subtalar joint implants are direct impact implants which create compression forces between the talus and the calcaneus that reduces subtalar joint pronation.

    I think that's very true. All arthroereising implants are axial axis-altering implants due to the change in the subtalar joint, spatial location that occurs with resetting the maximum pronation of the subtalar joint position to a new and more supinated postop rotation. So when you see a subtalar implant, it's what we're doing really where it's a direct implant, impact implant, with altering axis of the subtalar joint. Indications for uncontrolled hypertension – I'm sorry.

    [01:59]

    Uncontrolled hyper pronation, a normal to mild cuboid abduction, forefoot supination, sagittal plane subluxation of the subtalar joint, minimal calcaneal eversion and abduction, obliteration of the sinus tarsi and mild to moderate talar escape. It is indicated in decreased calcaneal inclination angle, primary equinus, ligamentous laxity, moderate pronation secondary to a calcaneonavicular bar or alternative, anteromedial facet coalitions, secondary effect of pronation and juvenile flatfoot, as well as hypermobile first ray.

    It's ideal in younger children although I've used it in many age groups. It's acceptable in adolescents and when you see an anterior break in the simian line. This is just an indication of a young girl with a severely pronated feet and she was flexible. And we looked at her foot and said, "Okay, let's see if we can just raise up and do what we call an internal arch to the foot." So remember, what you're doing in the goal of an arthroereising procedure is realign the peritalar subluxation, block excessive pronation, allow for normal motion, allow for functional adaptation, early weight bearing postoperatively, reducing the forefoot supinatus, support the talus and maintain space secondary to the CN bar or even a fibrous union. You're going to redirect the anteromedial facets as well.

    Restoration of the muscle balance around that joint is very important where you're taking something from pronation to supination, and you're maintaining or changing the arch height.

    [03:57]

    These are just a very long list of some of the clinical symptoms that we see with someone who may have severe pronation with what leads to pain in the sinus tarsi, including in kid's growing pain, leg cramps. They may not be very active. They have heel pain, postural pain, low back problems, fatigue. They don't want to wear their shoes. They can't tolerate a neutral position orthosis. When they run, they get shin splints and maybe plantar fasciitis as well. It's a long list of clinical signs and symptoms. In the clinical signs, you see people with poor postures. The medial part of their shoes are broken down.

    The loss of the medial longitudinal arch, apropulsive gait, early heel off, abducted forefoot and on the rearfoot, abnormal calcaneal position, the Helbing's sign, and then there's also because of that forefoot changes which leads to hallux or valgus deformity, digital deformities, hammertoes, and also soft tissue lesions plantarly.

    Some of the advantages of using this extra articular reversible, it's very easy to implant, easy to remove, and you do get early range of motion and weight bearing. Some of the goals of the procedure are to reposition the subtalar subluxation, block excessive motion, allow for a normal motion, allow for a functional adaptation and enable the foot to be more comfortable. This is just an example of a pronated neutral and supinated subtalar joint position, and you can see here where you'll actually have alteration of the posterior, and anterior facets and in the middle facet. Subtalar arthroereisis is a realigning of the subtalar joint with direct influence on both axis of the midtarsal joint as well as the first ray repositioning.

    [06:02]

    It allows subtalar motion during gait as it relates to the foot and the lower leg. This is just an example of where the implant is being placed and you can see it just goes right under the talus, between the talus and the calcaneus, and it actually just allows the talus to stay realigned and not pronate through. This is just calcaneal stance position with neutral position. You take them from a neutral to a calcaneal stance position to neutral by manipulating them. And if you can do that easily, a subtalar implant may be indicated.

    Subtalar range of motion is just an example of that where you have a really subluxed subtalar joint where you have forefoot supinatus and varus in the calcaneal stance position. That goes from neutral to valgus. Preoperatively, you're looking for all these clinical findings. If you draw the lines, you'll see how much you have valgus of the forefoot with Helbing's sign and that is a good indication for flatfoot reconstruction and maybe a subtalar implant. When you look on the lateral view, you can see the calcaneal inclination angle has decreased. You'll actually see a dipping of the talonavicular joint.

    Sometimes you'll see the piling of the metatarsals one through five onto each other so you can't really tell between the first and the fifth, and that's a supinatus. And then, you have talar beaking as well as the hypermobility of the first ray, and this is a good indication for a subtalar implant. Primus elevatus is also an indicator but that's because there's hypermobility of the first ray and lack of the peroneus longus functioning. So once you put a subtalar implant, the peroneus longus has a more mechanical advantage to pull the first ray down and you lose that primus elevatus.

    [08:03]

    The calcaneal cuboid joint is actually also looked for, for adduction. This is just an example of all that. The cuboid abduction, the anterior break in the simian line, widening of the forefoot, hypermobility of the first ray, the very enlarged navicular and metatarsus adductus are seen on the AP view or dorsal plantar view. We can see that here. And this is just a good example of someone who comes in with a severely pronated feet. They have no other symptoms but the way they walk, they feel unstable, and they're basically walking on the medial aspect of the head of the metatarsal.

    You can see here there's quite a bit of uncovering of the talus to the navicular and fully pronated foot. And when you put the subtalar implant in, you're holding up the talus and not allowing the talus to plantarflex and invert to cause that complete pronation, and here is the implant in place. Now, you notice when they're standing that the talus articulates very well with the navicular and there's no longer and covering of the talar head. Sometimes adjunctively you might need to attend to Achilles lengthening, gastroc lengthening or Kidner procedure in conjunction with just an arthroereisis, so here's just a quick picture of that where you're doing a tendon Achilles lengthening.

    Make sure when you do that you preserve the paratenon. That's important for nutrition and health for the tendon, and the gastroc lengthening might be indicated depending on where the apex or the deformity is. And Kidner where you're actually taking the posterior tibial tendon and realigning it with an anchor to give better function to the medial column.

    [10:02]

    The implants are actually multiple in nature. They've gone through many evolutions and this is just an example of some. Some are titanium. They started out with a polyurethane types, elastic type. And there are corkscrew-like and so these are all different kinds. I have one type I like the most. You'll get familiar with the kind you like and they're very easy to put in. Advantages of the titanium are high tissue compatibility. There's no real drilling of any bone or bone cement. Technically, it's very easy to perform. They're threaded. They're extra articular and they're radiopaque.

    And this is just an example of the dissection. It's a very simple dissection. You're going to open up the skin. You may remove the Hoke's tonsil. Some procedure say don't even remove the soft tissue or the Hoke's tonsil, and then this is where the implant is going to be placed. You can see here that the ligament and the sinus tarsi is remaining intact, and there's the actual opening where the implant will go. And here are the implant instrumentation. It's very simple. You have a guide wire and then you have the devices to measure the implant. It says error on the small side. I put them in too large and that can cause impingement.

    I put them in too small and it doesn't work so you really want to get it so that you – once you put it in, you put the foot – make sure you're putting the foot in neutral and make sure that it stays in the neutral position. But if you're right between two sizes, go to one smaller. It's simple procedure, you're opening a small incision, putting in the guide wire through the subtalar joint. And then, you're basically putting in the implant. You're making sure that it's in proper position where on X-ray you'll see that it butts up against the talus and calcaneus. You're 50% cover through the talus and then you put in some simple interrupted sutures.

    [12:05]

    So here's the guide wire going in. You can see here where you're actually putting – you're properly seeding it into the subtalar joint, between the talus and the calcaneus, and then the implant is in place. Once the implant is in proper position, you can almost immediately see that the talar navicular joint is more realigned and very rewarding when they first in right away. And here's the implant in place just to show you where it sits.

    Anatomically, one of the things you just have to avoid is the intertarsal artery mainly and there's no other major structures that you have to worry about too much. The range of the motion of the foot is important. So when you range the foot, what I do is invert and evert the foot, put the foot in neutral, and that's where I leave the implants and I test it at that point. If I'm going to error, I'm going to error on the side of pronation, not supination.

    These are some postop films of an implant in place where you can see where the insertion of the implant is. When you actually see and do this procedure, it's a really good form of postop of a patient who had a tendon Achilles lengthening and a subtalar implant with a Kidner, and it really is well aligned if you remember the earlier picture. You can see here – in there, you have a large amount of talonavicular congruity and talar declination which you want to prevent, the talar declination before and then postop, how it realigns. So you're actually changing the way the talus rotates on to the calcaneus.

    And here's another good picture of a flexible flatfoot in a young girl and this is before and after, and this is immediate after.

    [14:08]

    It's about one month postop and they have very little pain or discomfort. And one of the things that they see clinically is that it looks better immediately. Their foot looks straighter. Their knee looks straighter and they feel more secure. I call it the internal orthotic. Here's another picture of the implant in place and they are very much relieved. So in some of the areas where it's not indicated is in a very rigid flatfoot subtalar joint arthritis and peroneal spasms. Sometimes we try to put it in that rigid flatfoot. It really doesn't work well there. Except if you do a coalition resection and then you can put it in as a spacer.

    Before of adductus. This is something that we forget. When you unlock a pronated foot that has metatarsus adductus, the foot will look more adductus and you need to tell parents that. You need to know that that might happen. So in the long-term results of this, basically there's one thing that I think occurs the most, is the perceptible change. They look at their foot and there's much a better position of the foot. They have a longitudinal arch, the reduction of the forefoot. Lateral transposition is immediate. You have a reduction of forefoot supinatus. Their posture improves, reduction or elimination of postop orthotic control, although sometimes you might want to give them a neutral orthotic for a short period of time.

    It also maintains the tension and stretch on the Achilles. And actually remember that when you pronate excessively, you get equinus or vice-versa, equinus is pronation. But when you stabilize the foot, you don't have abnormal pull of the Achilles.

    [16:02]

    So I just want to show you this because we had a big debate about whether this was a good procedure or not. And in 2010, this male was 10 years old. He had a flattening of the medial longitudinal arch and the talus was basically uncovered over the navicular, and he was in a lot of pain with walking. And believe it or not, postoperatively, this was immediate postop and he looked quite good. The talus was quite elevated, maybe a little more than I wanted, but it was elevated and he had immediate postop result of pain in the foot.

    And then, that's in postoperatively the implant is well in place. You can see now that the talus to the navicular is well-aligned so you have good alignment on the medial column. And eight years later, he arrived back in my office for something very like an ingrown toenail and I went, "Oh my God, I have to take an X-ray. I forgot I even did this procedure." He forgot he even had the procedure and you can see here still the foot is – now, he is 18 years old. His foot is in full growth. He has a very stable medial longitudinal arch and no pain.

    So this is eight years postop just with the implant itself. And I wanted to show you that because there's a lot of literature out there that says that it's not well-defined, or more and more literatures coming out, but I find that this procedure in the right hands adjunctively can be very, very helpful. So this is before and after eight years later. So you can see how well – what I always look at is how much the talus went from being 50% uncovered to actually more anatomically aligned just over that period of time.

    And again, here is something that I do, do that's a little different. There's the picture right here. It's an ankle joint implant.

    [17:58]

    I don't know if you can see it but the foot was we wanted to block the pronation so we use this implant during the surgery just to put it in the subtalar joint to block the talus from moving while the ankle was healing, and actually that was a stable construct with that implant. It's not like 100% indicator we'll do this for all these procedures but it was a good alternative. Then, here in this picture, we did a medial column fusion and a subtalar implant to maintain the talocalcaneal articulation. We could have done a lot of other procedures but that seemed to be an adjunctive procedure and easy to do.

    So there's a lot of references out there on whether it's a really good procedure or more literature or data that hasn't come out. I think we're going to be finding a lot more literature and I think the literature is going to lean toward it's a really good procedure and a right place at the right time. Thank you.

    TAPE ENDS - [19:02]