157. Tarsal Tunnel Syndrome

Join Kasey on the PT Snacks Podcast as we delve into Tarsal Tunnel Syndrome, a compression neuropathy affecting the posterior tibial nerve in the ankle. This episode covers the anatomy, symptoms, risk factors, and differential diagnosis, while also offering useful clinical tests and treatment approaches. Ideal for physical therapists and students, the episode provides bite-sized, fundamental knowledge aimed at improving patient care.

00:00 Introduction to PT Snacks Podcast
00:17 Understanding Tarsal Tunnel Syndrome
02:59 Symptoms and Diagnosis of Tarsal Tunnel Syndrome
03:24 Who is at Risk?
04:39 Clinical Assessment and Differential Diagnosis
05:37 Diagnostic Tests for Tarsal Tunnel Syndrome
08:09 Conservative Treatment Approaches
11:20 When to Consider Surgery
12:51 Conclusion and Additional Resources

Transcript

0:30

Hey guys, PT Sachs podcast. This is Kasey, your host, and if you're tuning in for the very first time, what you need to know is that this podcast is meant for physical therapists and physical therapist students who are looking to grow your fundamentals and bite-size segments of time. Now, today we are gonna be talking about tarsal tunnel syndrome, which is in the ankle. If this is a new phrase for you, and that's totally okay if it is, but before we do that, if you have been listening to this show for at least three episodes and you found it to be helpful to you, if you wouldn't mind just pausing this. Writing a brief review wherever you're listening to it, that really does help the show to grow a lot if you've already done so. Thank you so much. You have a very special place in my heart. Now diving further into Tarsal Tunnel syndrome, we're gonna talk more about what this is, who gets it, what we do about it, and. Go from there. Now, before we dive into that, what I need you to know is that this is a diagnosis that maybe doesn't have the most robust, high quality research around it. On top of that, it is thought to be underdiagnosed but also easy to overlook as well. So I want you to use this episode as a launchpad to conduct further research and keep it in mind so that when you do have ankle patients with symptoms on the medial side or other places, which we'll talk about. That you maybe keep this on your differential diagnosis list and have an understanding of what exactly this means so that you can rule it in, rule it out, and use a combination of tests to prove your theory or your prove your diagnosis, I should say. So with that, let's review a little bit more on what Tarsal Tunnel syndrome is. So this is essentially a compression neuropathy at the posterior tibial nerve. More specifically as it travels through the tarsal tunnel. Hence the name on the medial side of the ankle, which is where the posterior tibial nervous. So we're gonna review anatomy'cause it's super important for this and all things physical therapy. Keep in mind the tarsal tunnel is formed by the flexor Retin inoculum, AKA, the laia ligament, and bordered by the media malleolus, tus, and calcaneus. Inside the tunnel, you're gonna find the posterior tibial nerve, the posterior tibial artery and vein, and the tendons of the posterior tibialis flexor digitorum longus, and flexor haus longus. There's a lot of stuff basically In this tunnel. Now, specifically the posterior tibial nerve, which is what we're talking about for compression neuropathy. This typically branches into the medial and lateral plantar nerves, and sometimes the medial calcaneal branches. When this nerve is compressed, it will lead to symptoms like burning, tingling, or numbness on the planter surface of the foot. Pain in the arch heel or medial ankle, and occasionally motor weakness in the intrinsic foot muscles because these are innervated lower down on the nerve and if the nerve is compressed, that is why we see these symptoms. So let's talk a little bit about who gets this. Tarsal tunnel can affect a pretty wide range of people, but we tend to see it most in runners and athletes that do a lot of repetitive impact sports. Individuals who have excessive pronation, flat feet or hind foot valgus. And this thought is more in that this is adding a strain or compression to the tarsal tunnel, right? We also can see this in adults age 30 to 60, although it can appear in younger athletes as well as people who have diabetes, inflammatory arthritis, or venous insufficiency. Risk factors, just to be a little bit more specific, include biomechanical factors like flat feet, hyper pronation, tibial torsion, structural factors like ganglion, cysts, lipomas and accessory muscles. Systemic like diabetes, hypothyroidism, and inflammatory diseases and external factors like poor footwear, tight laces, or ankle braces or trauma. So understanding your patient's history and in your assessment if you see things like this this is helpful as a piece of the puzzle as you are building your clinical picture. Now this condition can be under diagnosis a lot of times because these symptoms can mimic other common conditions such as plantar fasciitis, S one radiculopathy, or diabetic neuropathy. So with that, in our assessment, we don't wanna lose sight of the basics, right? The basics are where we get the meat of our quality exam. So ruling out other regions of the body, such as the low back, the hips, the knees, not just the ankles. Comparing side to side making sure that we actually have differential diagnoses on our list before we go into our objective exam, so that we're not just. Gathering a list of what's wrong with our patient, but we're actually putting it together in a clinical picture of what is the root of the problem so that we can effectively treat this. Don't forget about checking the basics like strength, range of motion, functional exams, things like that. Now for specifically the tarsal tunnel syndrome, there's not a single gold standard test. So the diagnosis is typically clinical and it can be supported by imaging or electrodiagnostics if needed. Remember the symptoms here are pain, numbness, or tingling in the sole heel or maybe ankle. So we may wanna do tests that help us to assess nerves.'cause that sounds like nerve, right? And in terms of the most useful clinical tests that I found some easy ones to incorporate would be tunnel sign where you tap over the tarsal tunnel and it's positive if it reproduces their symptoms. Right now, sensitivity and specificity are low to moderate, but it's really easy to do so might as well. One test that has a high specificity. As well as the sensitivity of about 82% is the dorsiflexion aversion test. So basically you're gonna passively dors flex and E for the ankle while dorsa flexing the toes. So you're just trying to crank up on that tarsal tunnel and see if they can reproduce their symptoms. And then there's another test, the triple compression stress test. So during that, you plant or flex invert and apply pressure to the tibial nerve. This also has a high sensitivity and specificity. When I am talking about electrodiagnostic tests, I'm specifically talking about EMG and nerve conduction studies. These can be helpful but limited, so the sensitivity can be found to be as low as 50 to 60%. So don't put all your eggs in one basket if this is the test that helps you decide on your diagnosis. But it's helpful as a piece of the picture, right? Because while there are newer protocols that can improve accuracy, it's not always widely accessible. And it can help rule in neuropathy or rule out other mimicking things. But false negatives are very common, especially in earlier mild cases. Now imaging tests that we can also use would be an ultrasound or MRI. An ultrasound can be good for helping to detect if there's any nerve swelling or space occupying lesions.'cause again. This is a nerve compression disorder, right? So we're looking for, if we think this is it, where's the nerve compression coming from? MRIs can also be great for looking at if there's any anatomical abnormalities, cysts, tumors so it's best to use a multimodal approach, not just rely on one test as a definitive. Now in terms of treatments, let's say, okay, we've rolled this in. We feel pretty confident that we're reproducing the same symptoms with a lot of these tests. Conservative treatment is typically where you're gonna start. For a lot of people. It's great for if symptoms are caught early and there's no motor involvement. But. We need to make sure that we are monitoring for progression of their symptoms, right? Because we don't love when people have long-term nerve compression so typically, depending on why we think maybe this happened in the first place, especially if it's from a lot of repetitive stress in this area, maybe we do activity modification like our long distance runner, right? Maybe we're trying to reduce aggravating activities so that we can get that area to just calm down so it's more receptive to our other treatment. Maybe we're utilizing pain management whatever that looks like for people in the research. Sometimes they'd use ice tins, ultrasound, some evidence for shockwave therapy. They may improve tolerance to movement, but not an end all, be all right. It's pain management, not the solution to the problem. Orthotics and footwear could potentially be some low hanging fruit if footwear is a factor in this or if we're trying to offload whether for instance, if someone's an over pronator, maybe we just see if they feel better with a medial arch support. A star as like stretching or strengthening. We wanna monitor the muscles that are innervated by these nerve branches that are compressed. So looking at our intrinsic foot muscles as well as our posterior tibs strengthening the gastric sous. All of these can help to support the medial arch and hopefully offload the tarsal tunnel. Tibial nerve gliding can be used if there is a neurodynamic aspect where there is sensitivity to movement for the nerve. In some cases using the nerve gliding can help it to reduce its sensitivity and help with nerve mobility. Make sure you're monitoring your symptoms so that you get the results that you want. In terms of what their irritability level is, we can also try and utilize manual therapy to offload best we can, the nerve compression. If someone is dealing with a pretty significant nerve compression or if there's some sort of inflammatory component or space occupying lesion, there's only so much that we're gonna get probably from manual therapy, patient education, like good footwear for them. How to manage flare-ups activity, pacing and symptom tracking. We, we obviously wanna educate our patients on how to manage their symptoms and take care of themselves, but here's the caveat. Nerve compression issues. We don't really wanna just. Let them linger for long periods of time. So if someone's not responding well to physical therapy, you're noticing a lot of atrophy or weakness or worsening symptoms. There's only so much that physical therapy can do, right? We need to refer them to a specialist. If we are seeing these motor weakness, intrinsic foot atrophy, worsening symptoms if imaging is showing space, occupying lesions, or if they've failed conservative care, that is where surgery comes into the mix, where these patients may get surgical decompression so that we can offload the nerve and then allow it hopefully time to heal. So surgical decompression has a reported success rate of 75 to 90%, especially if there is a structural cause present. But if we're catching this early enough and symptoms are mild, it's ideal to start with conservative treatment and be able to get our patients going to see what we can get now as a review. Tarsal tunnel syndrome is a posterior tibial nerve entrapment inside the medial ankle. We wanna keep in mind it in our differential list and use a combination of tests clinical assessments, the patient's history, their symptoms, all to come to a conclusion, not just one special test and assume that's the case, right? Imaging and EMG can help support your findings, but aren't always conclusive, especially in isolation and. And we wanna make sure that we are monitoring their symptoms in conservative care. So that they are so that if they need something more than conservative care, we can quickly get them to the right place. So that's it for today, guys. I hope this all was helpful to you. And if you. If you do have any questions, feel free to reach out at PTs Snacks podcast@gmail.com. Or there is a send a text feature in the show notes you can definitely use as well. If you have future requests for topics that you wanna go over. Just shoot me an email, shoot me a message. And I'd be happy to try and work that in and cover that topic to the best of my abilities. Just keep in mind that the topics for the show are intended to be more fundamental and foundational. I try not to cover topics that don't have a lot of research over them yet. Now on a side note, if you are trying to get more CEUs for maybe renewing your license or you need a home exercise program builder for your patients and you want something that's Virtual Med Bridge is actually offering listeners over a hundred dollars off just for being here. So if you want that. There is a promo code below in the show notes that you just use that checkout for whatever level that you want, and then that should be applied right there. And they have specialty exam prep. They have tons of courses that are CEU courses, webinars, and like I said, there's even a tier that they have where you can put together pictures or videos of what you want your patient to do. You can type in how many sets and reps and what they wanna do, and then either print that off for your patient or email it to them and that patient can go and watch videos of how to do that exercise, which is a really nice feature. So definitely check that out below, and if you're a student, you get an even better discount. That's it for today, guys, and I hope you have a great one. Until next time.