Posterior Tibial Tendon Dysfunction, Dr. Evan Loewy

So posterior tibial tendon dysfunction adult flatfoot deformity. Still no disclosures. All right. So I’m going to briefly go over this and then talk about some keys to successful non operative management and then provide some tools for patient education. So posterior tibial tendon dysfunctions the most common cause of adult acquired flat foot deformity. It’s more common in women and it’s most common in the sixth decade of life. So risk factors are obesity chronic steroid use in zero negative inflammatory disorders. So as far as the anatomy. So the posterior tibial tendon runs immediately behind the tibia behind them medial manuals and a very shallow groove. It’s bound tightly by a flexor retinaculum and then inserts on actually eleven different points throughout the bottom of the foot. So an extremely broad insertion.
So important things that make this extra incredibly important tendon – very susceptible to pathology and dysfunction are a couple of things one. There’s actually a vascular watershed region closer on the left picture by that leg the lower arrow there’s a poor blood supply region there. Also, despite how important this tendon is there’s really only two centimeters of excursion. So it doesn’t always work in two centimeters. So if you imagine then you have very small disruptions or partial tears that can cause a huge effect because it’s such a big percentage.
And briefly the also important for this talk is the plantar calcaneonavicular ligament or the spring ligament so that goes from the sustentaculum tail of the calcaneus to the navicular and this is responsible for maintenance of your longitudinal arch. So as I mentioned you have. A sharp turn. In a very narrow groove which is making the susceptible to repetitive micro trauma in an area that has poor blood flow which essentially can over time lead you to a non-functional tendon. So it’s very rare to have a full rupture of this tendon but typically what happens is you have chronic degenerative changes small partial tears and it essentially lengthens enough to be intact but not have any to haven’t two centimeters of excursion. So there’s a clinical photo here. The one that’s in the pickups is this posterior tibial tendon and see at least just doesn’t look very good compared to the one that’s immediately below it is normally a smaller tendon but not that big a difference and it’s shinier than the unhealthy posterior tip tendon. Try not to nerd out too much on this but I think this is incredibly cool and one of the reasons why that if an ankle fellowship so where this does its magic is the transverse tarsal joints so that your talonavicular and joints.
So the picture is not as incredibly important in terms of orientation but the key is when the posterior tibial table tendons relaxed and your foot is even rooted or essentially in that flat position the two joints the plains of motion are lined up. And so imagine it hinges on a door. So they move freely it’s a supple joint that puts your tip 10 and fires and that spins the four foot into super nation. So it makes the joints no longer in here. And so if you imagine two hinges on a door that aren’t lined up it’s not going to move. So that makes your foot able to be a rigid lever arm for your gastric to fire and allow someone like Zion Williamson’s friends two hundred eighty pounds leap through the air dunk a basketball and then his push your tip relaxes just joints become supple again and he can come down and all that force and land on his foot and not have injury and can continue running.
So you lose that ability if the function is a tendon is no longer functional. So, from a history standpoint patients are going to come in and say that I’ve got fallen arches. So you’ve got to ask did this just happen or is you’re always had fallen arches kind of you know your whole family had fallen arches just see if there’s a recent change that can affect things in the early in the disease process to have medial pain late in disease process they’ll go more lateral pain as the cockiness kind of starts hitting underneath the fibula and they have some of their impingement. My personal favorite is the guy at the running store said I’m an over pronator fix me.
So from a physical exam standpoint important alignment which we hit on the first luxury of hind foot values mid foot plaintiffs are just flattening of the mid foot and then four foot abduction or you’re too many toes sign. So that’s kind of here we already talked about that same pictures from before but just to just to go back over it. Your hind foot Vargas too many toes.
Again you want to have that double in heel rise also with this pathology you want to do a single limb heel rise and you can compare on both sides but especially on the pathologic side or the one you’re concerned about if they can do a double limb heel rise and that corrects that’s showing that they have a flexible deformity. The importance of the same single in your eyes is kind of like I was talking about with jumping and the way that this tendon functions if they can’t physically do a single limb heel rise the tendon is non-functional and that’s where the problem is coming from likely. So this is just the again that picture showing that correction with your heel rise. So when you when you have him sit down and you do your physical exam you want to check for swelling and tenderness along the course of the posterior tip tendon.
So in some studies that show actually these findings and swelling and you know we say bogging this or that tendon sheath is is equally as sensitive and specific to MRI for pathology in that tendon in an acute setting in check for sinus tenderness or something with a tenderness isolated plus your tip strength testing and we talked about you want to check your ankle and subtalar range of motion and also stability again looking at the deltoid like I talked about that can come into play later and then your silver skull the key with this in this situation is that when you do your test against the same slide. But the key is you hold the hind foot reduced in the neutral on the normal position when you do this test because if you leave them in Vargas and they’re out to the side you’re not going to notice as much of a difference.
If a patient gets to a situation where they have deformity then by definition, they have some tightness in this situation something is something is tied to the heel quarter of a gastro so for the foot. So the key here is you can you reduce the hind foot right. So there’s gonna be a picture here and so you’ll see examiners twisting it over and reducing the hind foot. It’s a normal position. Okay. So can you do that. If yes what happens to the fore foot. Do they have residual fore foot various or super nation which basically they’re having here right? So that that angle or those lines that should be perpendicular the fore foot should come and be perpendicular to the long ass of the tibia. The reason that that happens is if you imagine if your HF valgus and if you do it kind of on your own you can’t walk like that.
So you’re fore foots twist and supinates to be able to be flat on the ground. And so as the disease process moves forward and continues that becomes somewhat fixed. And so when you swing the heel around the four foot stays up like that and then you also check if that’s flexible by pushing up on the lateral border of the foot. So the fifth metaphorical and see if then you can passively correct that. So this is more typically all this is some of this is based on non-operated treatment like we talked about for bracing but again also can be some surgical treatment.
So X-rays brief step on the soap box I implore you anytime you get foot or ankle x rays unless the patient is in unable to perform weight bearing x rays due to paralysis or acute injury it’s always better to order weight bearing x rays that are infinitely more valuable in terms of gaining information.
So we’re going to show you here and this is something cool you can do with patients too and that kind of a way that you can show what you’re talking about and draw lines on the x ray and they don’t think you’re just crazy in saying random things. So your memories angles when you look out in the lateral so you have a line that goes from through the mid substance or the middle of the talus and the long axis of basically just where the talus is pointing. And then one that goes through the shaft to the first met at torso. So they should be in a perfect world. Linear. So here in this patient there are linear so degrees of those two lines of between plus or minus four degrees is considered normal.
But this is what it looks like. Usually it’s not a question. So you can see that those are completely not co linear it’s not close to four degrees. And then on the AP there is. We will talk about the AP. It’s less specific in terms of your testing but it’s kind of something again you can show patient you’ll see how it looks abnormal here you’re not really looking for. For them being co linear as much as parallel more importantly on the AP you want to look at talonavicular uncover it. So for all intents and purposes right.
So on for intents and purposes it’s a ball and socket joint and so they should be lined up on the AP. And so when you get on coverage then that’s your fore foot abduction that you’re too many toes sign. The degrees standpoint considered seven degrees more than seven degrees is abnormal.
But really when we look at it we look more for percent on coverage. And so it’s been shown that 30 percent or more on coverage suggests a spring ligament injury. And so this will be in the abnormal so here there’s no cooling here. And then you’re on coverage. So if you have more than 30 percent on coverage that’s the spring ligament injury if you have more than 50 percent that’s what some people argue that suggests that you need to do a lateral column lengthening which is a surgical procedure. MRI is a little controversial.
Most people I think order them and find value in them some of that some schools of thought say it’s not necessary but without contrast to the ankle you’re looking at the push you to tendon initially in the early stages. Is it true tenosynovitis or is there some partial tearing that can guide your management a little bit later stages. Really, I think the key for later stages is you’re going to look at your sub talar navicular and your tibial talar ankle joint. See there’s early arthritic changes that’s going to affect your response. Different surgeries. So from an imaging standpoint so this is a patient with stage two which are going to briefly but on the Samuel T one, you can see some degenerative changes in the posterior tip tendon. Some longitudinal tearing which is classic for that. And then on the STIR on the actual you’ll see fluid around the tendon. So This is kind of an acute inflammatory type of situation. Similar patient but more advanced disease. So on the corona story you’ll see subchondral edema in the sub talar joint suggesting arthritic change in sub fibula impingement. Same type of sagittal T1 but if you look at the actual STIR on this patients hardly any fluid. So as it burns out and they get more of a rigid deformity they usually don’t have that knee to ankle pain or tenderness anymore.
So in 1989, Johnson and Strom suggested this classification system. So stage one is just post tenosynovitis and no deformity they can straight leg raise albeit with some pain potentially but overall just this tenosynovitis no flatfoot foot, nothing like that. Stage two is when they get the flatfoot. So they have arch collapse but it’s flexible. So then when they sit down you can put the foot with your hands you can put it and make it look like a normal foot. These patients cannot straight leg rise excuse me single limb here dies.
Stage three. So when this becomes a rigid deformity which basically is when it comes arthritic so the sub Talar and talar navicular joint become arthritic rigid and that changes your management. Stage four is a little controversial. This was proposed by another surgeon some like he says that this is a continuation of that disease. There’s too much stress on the medial ankle that deltoid becomes efficient they get ankle valgus. So my school of training and thought is that it’s actually the opposite. Chronic medial ankle instability leads to a compensatory and adaptive flatfoot so that they can be flat again.
And so we’ll kind of show you a case that kind of shows that. So one thing that I say is that you know I’m a surgeon but I want to treat you without surgery first and then if you need surgery we can do it. I know how to do it. So flexible corrective. And then if it needs surgeries extra articular surgery and I’ll show you what I mean by that rigid accommodative an intraarticular surgery. So consider the treatment for stage 1 and 2 is all about the tendinopathy and the tendonitis. So you rest attendant. So you can start with an ASO brace or lace of ankle brace that’s gonna control your inversion version not so much plan or flexion dorsal flexion sometimes that’s enough if it’s not you can do a can boot if they can put weight in the Cam boot or in the brace and be comfortable then you can encourage that because at the weight bearing even if it’s partial stimulates healing of the tendon shorter course of anti-inflammatory is physical therapy is helpful but it’s key to not start eccentric strengthening of the posterior tip and until their acute pain has resolved and then you begin that’s strengthening Protocol it’s important to avoid oral or injectable steroids here because although they will feel better it’s bad for the tendon and then if it calms down you can do maintenance mostly bushy custom or over the counter arch supports.
Or specify issues. Stage one. After three months of failed conservative or if they haven’t a known systemic inflammatory disease. Six weeks tenosynovectomy.
So basically you can see there’s a bunch of inflammatory tissue on the tendon and the left with arrows pointing they took it off it’s in the foreground there and the tendons healthy underneath sort of second area for stage to this joint sparing surgery and you’re gonna ask the armies or tendon transfers.
So this is a patient i took care of this year and fellowship and so is a 55 year old female flexible flatfoot progressive medial pain now responding to bracing anti inflammatory etc. And so here’s your lines that we drew and show you that that we did surgery for the right reason that she has a problem here at least really graphically.
So here’s your post OP. So this is about four months post op. So we did a medial displacement.
Calcaneus, posterior tip agreement FDL tendon transfer and cotton. So the important things here is this. Those are all big words but the joints are spared. They’re still flexible and then we corrected those lines. And she’s doing a lot better. So stage 3 and 4 this is more of an arthritis type of thing like we talked about so you’re aiming more similar to management of arthritis so more longer term anti-inflammatory. Intra articular steroids are OK. If they’re Stage 3 you do in articulating info or what’s going to Mars on a brace. That’s me in the bottom left, if the ankle joint itself is infected then you’re gonna need the more full length solid AFO so for stage 3 if those fail. This is a patient. Similar in terms of the lines but the keys they have sub talar and talar arthritis. This a 74-year-old female rigid deformity and persistent pain not responding to conservative treatment. So we did took down those joints realign them and fused them in the correct position and so she was doing much better your lines was restored and she’s in a regular shoe about three and a half months post op and feeling a lot better.
And then finally in stage 4 again controversial depends on your train of thought or kind of your school of thought rather if you think it’s a true stage for like that. Like Myerson proposed you do hind foot fusions similar to what you just saw but with a deltoid reconstruction or you do a fusion of the sub talar and ankle joints which as you’d imagine is not exceedingly functional but if you’re from the correct school of thought and you think it’s the ankle that leads to the flatfoot you do mid foot or hind foot fusions to correct that instability that secondary instability the foot and the deformity and then either a single or second stage you can do it total arthroplasty to address the ligament insufficiency and so briefly just gonna show you that. So this is stemming through your active guy had a bad ankle sprain many years ago he’s had flat for his whole life but recently all of a sudden it got worse.
He’s got more pain and so you look at these Okay well he’s got all these lines. The lines are off, he’s got Valgas maybe even some syndesmotic widening. He’s got to be rigid. No, it’s completely flexible deformity. He can do a single like heel rises everything corrects you hold he sits down you correct as hind foot the foot looks normal. So to me that’s not a continuation of the other process. So he took him the first stage did talonavicular and sub talar fusion and then did deltoid in sin as monarch reconstructions and so you’ll get the top when you say well that that sounds cool but the ankle still doesn’t look right which is true there is increased laxity still but at this point he has a good endpoint. So six months later we went and did a total like arthroplasty.
And now you can see it’s lined up better. And that’s because he had that better end point now firm in point with the new deltoid ligament that we can use the tension that polyethylene. This was at four months after the second surgery. Again, walking regular shoes Rigo SHU for a couple of months already was doing well so that wasn’t too much but conclusions and generative progressive condition most commonly seen in females in the sixth decade of life. There’s no deformity but there’s pain you rest attend and you rehab. And if that doesn’t work then you just clean out the tendon around the tendon. If there’s flexible deformity corrective bracing and rehab extra particular surgery rigid deformity accommodative bracing you treat the arthritis and then in take out surgery if needed. Thank you.