digestive e-blast. Well, we're fortunate today to have Ryan Kruse. Ryan is one of the hosts at Iowa with MEDERIC, and Ryan has done a great job help coordinating this and eventually take this over. He did his fellowship with MEDERIC, so his ultrasound skills are quite advanced. And we were just talking, he does a lot of plantar fascia 10Xs, so therefore his diagnostic ultrasound for the plantar hindfoot is advanced, and so he's going to present a case today called plantar hindfoot pain. So Ryan, take it away. All right, thanks, Doug. Can you see my screen? Are we good here? We are. Okay. All right, so good morning, everybody. Thanks for the intro, Doug. So like Doug was saying, the case today is a patient with a painful plantar heel, which everybody who's on this talk right now probably has had this patient in their office more times than you can count. So we will just get rolling here, if my slides want to. All right, so no disclosures. I don't often do this, but I think it's relevant here. So just a quick thanks. MEDERIC has been stuck being a mentor of mine since he was stuck with me as a fellow. And then obviously these guys on the right, so Jason Bajigsalan and John Finnoff have really been instrumental in my ultrasound education, so I'd be remiss to not mention all these guys. So the objectives here, the whole goal of this series is really to kind of teach and show how we go about evaluating somebody who comes in with a specific complaint. So for me, for plantar hindfoot pain, I think it's important to not just focus specifically on the three things that are on the plantar heel and really think about the patient and how you would sonographically evaluate that patient in order to obtain accurate diagnosis. So we'll kind of go through at least my protocol on what I do for most folks that will come in with plantar heel pain. We'll talk about some examples of certain findings that we will commonly see, particularly pertaining to this specific patient. And I think the other important part here, and folks that have presented previously have mentioned this as well, I think a lot of us can find a specific structure, snap a few pictures, and that's it. But I think being able to find the structures, to take adequate images, and then be able to portray that information in a diagnostic report is a tough skill to master. And so I think there's value and importance in really going over how we write these reports. And I will, sort of like Doug did previously in his talk, I'll break down my diagnostic report per structure as we go through this, then I'll show you the full report at the end and maybe mention briefly my thought process on why I do things this way. So we will get rolling here. So this patient, I saw her, oh, I think eight, nine months ago, but she's a 34-year-old lady. Again, typical story, atraumatic heel pain. You just kind of one day woke up and things didn't feel that great. No trauma that she can recall. All of her symptoms really localized to plantar medial heel. But as with most of these patients, they can radiate down to the arch. There may or may not be some buzzing or tingling associated on the plantar foot. And then again, she wakes up in the morning, she steps down, bad deal, you know, very symptomatic. Then she'll walk a bit more and symptoms improve. But then by the end of the day, things are quite uncomfortable for her. Her examination, pretty straightforward. She's tender along the medial plantar heel, a bit to the medial, or I'm sorry, plantar midfoot as well. Passive toe extension somewhat reproduces her symptoms. And then really, really no tunnels over her medial ankle, specifically in the tarsal tunnel. So these are her x-rays, her foot x-rays. So nothing all that extraordinary here. You can see a little calcaneal enthesophyte here. Maybe there's an Achilles enthesophyte, little hagglings, but otherwise everything else looks relatively okay. So my general scanning protocol here is sometimes a bit robust, but I think there's a reason for it. There's a lot of mimickers of plantar fascia or fasciitis, right? So I will always start with the basics, you know, plantar fascia origin, fat pad, and calcaneus. And those are my, you know, hard and fast images that I will obtain every single time. We do know that some of these nerve entrapment syndromes can often mimic plantar fasciitis and plantar heel pain. So I will look at the medial ankle, oftentimes looking at the tibial nerve specifically, as well as its corresponding distal branches to, number one, look for any abnormalities. And oftentimes, you know, being able to elicit reproduction of symptoms with sonopalpation, I have found has been really helpful for me. So I'll do that. Depending on the patient, I'll typically pop over quickly to the posterior hind foot, specifically the Achilles, because again, you know, I've been fooled a couple of times where somebody for all the world sounds like they've got plantar fasciitis and their plantar fascia looks stone cold normal on ultrasound. And then we look at their Achilles insertion and they've got, you know, riproar and tendinosis or even like a retrocalc bursitis. So I started incorporating that on patients as well. And then I think there's a couple other things, other structures that you can look at as indicated, you know, I will typically look at the at the lateral cord insertion on the base of the fifth in a fair number of patients. And then, you know, certainly if you're concerned for one of these tibial nerve entrapment syndromes, looking at foot intrinsic musculature or, you know, atrophy or fatty changes can be, can be helpful, but admittedly, I don't, I do not do that in, in every patient. So quickly, plantar fascia anatomy, you know, I think oftentimes we throw around, you know, interchangeable names for, for these different portions of the plantar fascia. And I think it's important to really understand, you know, what we're talking about here. So the majority of, of, of plantar fascia changes are going to involve the central cord, which is this green structure that we can see here. Everybody knows this, you know, originating, originating from this medial calcaneal tubercle and, and extending distally. You know, when we talk about the medial band that is not interchangeable with the central cord. So this is very different structure. It courses medially just off the calcaneus and essentially covers the adductor hallucis muscle as it extends, like I said, medially. And then the lateral cord out here, you know, the vast majority of the structure is going to originate, I'm sorry, insert on the base of the fifth. Some folks will have some distal extension into the, the distal foot here, but the insertion on the base of the fifth is, is a common site of pathology. So just a bit of nomenclature there, but I think is important when we're, you know, writing these reports and, and communicating with each other. So this is our patient here. So this is her plantar fascia origin here. So on the top left here, I've got plantar fascia and long axis with proximal to the left and distal to the right. We've got calcaneus here, and then this is all her, her plantar fascia here. So very thick, very edematous, very hypoechoic. You can see somewhat normalization of, of fascia echo texture here. This is the correlative view in short axis. So now we've got medial to the left. This is calcaneus. All of this is very thick. Like I said, edematous plantar fascia. I will always measure this. I think this is helpful. So this, this patient had a measurement of about 8.5 millimeters. I typically use about four millimeters or 0.4 centimeters as my cutoff of, of normal. So we already know that she's got some stuff going on in her, in her plantar fascia. And I'll typically follow out central cord, you know, pretty far into the midfoot and even maybe the proximal forefoot. Because we do know that people like this patient here can have some, some distal changes in her plantar fascia. So this little focal fusiform swelling here, this is all plantar fascia with FDB muscle deep, normal fascia approximately, normal fascia distally. So this focal enlargement is a, is a fibroma. So she's, she's got a couple things going on here already, which, which may explain why she has both heel as well as, as well as arch pain here. So that's my evaluation there for central cord. And so my report at this part, or I'm sorry, this portion of the examination would be that the central cord is thickened with hypochoic heterogeneity, no tear. I will comment on the thickness and then, which is like I said, 8.5 millimeters, and then also describe hypochoic thickening approximately 1.2 centimeters distal to calcaneus. I'll comment on the length, which in this patient, it didn't show up in the calipers here, which is 2.6 centimeters. I will measure the fibroma thickness just for completeness sake. And that will be my, my description of the central cord here. Just quickly, a couple of correlative examples here. So at the insertion, we can see, you know, in this patient, this little intrasubstance tear as denoted by the yellow arrow here. So both the long and short axis here, and some folks will see some calcific changes at the origin, which I think can often be quite, quite uncomfortable. And then plantar fascia rupture here. You basically see, you know, complete loss of tension between these two ends of the plantar fascia with really, you know, no, no normal fibers spanning the gap here. So this is not our patient again, just a couple of correlative examples. So then moving on to the lateral cord. So again, we've got proximal left distal to the right. Here's her lateral cord plantar fascia. So it looks, it looks fine. So it's got, you know, normal hyperechoic appearance. It's well organized. It's not edematous. Here it is in short axis. It's the structure right here. And then again, I'll often follow these out to the base of the fifth insertion. There's a bit of nuance here with the lateral cord and then fibularis brevis tendon inserting out here. But as long as you follow this out from a proximal location, you can find its insertion on the, on the base of the fifth there. So for this, I would say that lateral cord is normal in appearance, no tear. I'll measure this, you know, maximal thickness at 0.25, 0.25 centimeters. So rather quick report there. And again, just another correlative example here, primarily distally. So this is a prior patient that had pretty robust distal lateral cord fasciopathy right at the base of the fifth here. So something to always keep in mind. I know this is a plantar hindfoot case, but, you know, really follow these structures out because sometimes you can be surprised at, at what you see here. Just to comment on this, the medial band of the plantar fascia, I personally have not seen any pathology in this region. Maybe it's seen me, but I have not seen it, but, you know, it's this kind of fibrous tissue that, like I said, will branch out medially and cover the adductor hallucis. And you can see in this cine loop here, you can see this hyper-echoic structure that is, like I said, kind of fanning out medially here and coursing over that muscle that I mentioned. So that would be the medial band here. And to be honest, I don't often comment on this because, again, I haven't really seen much pathology here, but just for completeness sake, you know, if that's what it would look like in this patient, the medial band is normal. From there, I'll move on to plantar fat pad. And as everybody knows, you know, plantar fat pad is a shock-absorbing tissue in the heel. It's like the cushioning within a, you know, a good pair of running shoes composed of both these macro and micro chambers, again, that are primarily there to absorb shock and prevent that shock from being transmitted deeply into plantar fascia and calcaneus here. So certainly, you know, pathology to be seen in this region. In this patient, this is her plantar fat pad. I'm sorry, this is not our patient. This is a correlative example. I, for whatever reason, couldn't get my images from this specific patient. But for fat pad, you know, we'll look for loss of this kind of normal homogenous equitecture here. So it becomes hypoechoic and edematous. You can see fat fracture. I'll show an example here in a second. And then oftentimes, or every time, I'll measure this. So I'll measure an uncompressed heel pad here, which measures 1.37, and the maximally compressed, which measures 1.17. We'll calculate a heel compressibility or a fat pad compressibility index. And then I'll also grab a CINI loop. And usually, I'll eyeball this. And I'm looking for around 50% compression with sonopalpation. And then if, you know, if there's a screaming abnormality there, we'll take measurements. But in this patient, her compressibility index was normal. This is from a Derrick's paper a couple of years ago, just showing what we can see in the plantar fat pads. So this hypoechoic region demonstrates these edematous changes. And then oftentimes traumatic, but not always, you can see these little hypoechoic clefts within the fat pad, which would be representative of a fat fracture. Plantar fat pad abnormalities are quite a challenge from a treatment perspective. So I always know that if I see something like this, along with my plantar fascia problem in a patient, that we're going to have a little bit of a challenge potentially from a treatment perspective. Calcaneus, quickly, you know, I'll take a look at this as I'm looking at plantar fascia. You know, clearly, you're not going to do a full bony evaluation. That's not where ultrasound is useful here. But we can catch some pathology here. So in this patient, long story short, this is her calcaneus, this hypoechoic linear structure here, nothing abnormal here. And so really, you know, I'm not doing a full calcaneus evaluation. I'll look at the level of plantar fascia, maybe a bit medial here. And then if I see something abnormal, I'll comment on it. And more often than not, you know, I'll just say that the evaluated region calcaneus is normal here. So this is from a paper a couple years ago, two years ago. So some things that we can see, and what I've seen a couple of times, is a calcaneal stress reaction. And I've seen this, you know, primarily in somebody who has a pretty crummy fat pad, because again, those forces are not being absorbed by that fat and they're getting transmitted deep to the calcaneus. So we can pick up stress injuries here. You know, in this patient, you see this periosteal edema as noted by this hypoechoic region superficial to the calcaneus, and then this lights up with Doppler. So that would be concerning for a stress injury. This is a patient a couple years ago of mine who had vague, you know, plantar medial heel pain, high-level athlete who we were scanning, we're taking a look at bifurcate ligament, and then we saw this little cortical disruption at the anterior process calcaneus. So this patient had a fracture there. So again, while not common, you know, I think there is some role in at least commenting on the bony structure, specifically calcaneus when you're doing these scans. Next, I'll move to the medial ankle, specifically looking at the tibial nerve and its corresponding branches. You know, I'll certainly take a quick peek at, you know, the tendons in the tarsal tunnel at the medial ankle, but I don't often do full evaluations of those tendons. My primary concern here is the tibial nerve, which we can see as this honeycomb appearance in the middle of this picture here. So this is, I stole this picture from Dr. Smith's paper seven years ago, because the anatomic dissection here is fantastic. So we can see tibial nerve here, and then the branch points into the, you know, three corresponding distal branches. Now, primarily, you know, we'll see medial calcaneal branch come off first, posteriorly, followed by, you know, a division of the tibial nerve into medial lateral plantar. But what I've learned as I'm scanning more and more of these is that that is not always the case. And there's quite a bit of anatomic variation. So really tracing these nerves distally to see where they go, and then coming back approximately will let you identify and confirm which nerve you're specifically looking at during that scan. This is our patient here. So I've got a posterior to the left, and then I've got a posterior to the right. So I've got a posterior to the left, proximal, I'm sorry, anterior to the right here. Here's her medial plantar, lateral plantar, and medial calcaneal nerves, all of which in this region look okay. Next, I'll really target two of these nerves and follow them distally. And there are specific entrapment points that can cause plantar heel and foot pain. So one of the most common ones is this Baxter's nerve is the first branch lateral plantar nerve here. Again, this image with the bottom image here, I stole from Dr. Smith's paper, but the first branch lateral plantar nerve is a mimicker of plantar heel pain, plantar fasciitis. And typically I'll follow it down distally until I see it at this interval, which is the interval between adductor hallucis and quadratus plantae, excuse me, looking for focal compression in this area. And also if there's very specific focal pain with sonopalpation here, I think that can be helpful looking at this as the culprit for the patient's plantar heel pain. But in this patient, her first branch lateral plantar nerve was normal, and she had no pain with sonopalpation over this region. Next, I will follow medial plantar nerve distally, which courses right over this intersection between FDL and FHL, which is another site of entrapment. Admittedly, this is a bit more distal than somebody who has truly plantar heel pain or approximately, but still for completeness sake, I will follow this out and trace it. So we can see here this structure, this honeycomb hyper-echoic structure here is a medial plantar nerve. This is navicular up here. And we've all heard of the masternod of Henry. So where FDL and FHL course near each other, FDL on top of FHL, and this can be a site of entrapment of the medial plantar nerve. So I will scan this as well. I think my sending loop stopped. You can see here medial plantar nerve is here, and here is FDL and FHL deep. So again, I'll look for any focal entrapment in that region. And again, I rely heavily on pain with sonopalpation. And I think that's a trick that can be really, really helpful, especially for some of these small nerves, which it can be sometimes challenging to see vesicular loss in a nerve where you really can only see a couple of fascicles. So I rely on pain with sonopalpation quite often in these folks. And then once I go through, like I said, tibial nerve proper at the tarsal tunnel, as well as the distal branches, primarily first branch lateral plantar nerve and medial plantar nerve, then I'll comment on all of those structures. So for this patient, tibial nerve in the tarsal tunnel is normal without focal compression or vesicular loss. And then again, medial calcaneal, medial plantar and lateral plantar are all normal in appearance. So foot intrinsic musculature, I'll kind of fly through this when I'm doing the scan, unless I'm really concerned about, like I said, a focal nerve entrapment. So this is our patient here, plantar fascia up top with FDB muscle belly deep to it. And you can see the normal aqua texture of the FDB muscle here, which looks stone cold normal. This is from Doug's paper back in 2014, which shows this kind of muscle atrophy or fatty infiltration of the ADM muscle here. And I think deciding which muscles to investigate really depends on which nerve you're concerned about. So we know medial plantar nerve is gonna innervate, advector hallucis, FDB, FHB and the first lumbrical and all other intrinsic muscles are supplied by the lateral plantar nerve. So you can pick your muscle accordingly. And I don't know if it's helpful or not, but I often think about the lateral plantar nerve as analogous to the ulnar nerve in the hand in terms of muscles that it specifically innervates. So with this patient, I guess I didn't comment on it, but her foot musculature was normal in appearance. And then again, I'll oftentimes just to complete the examination, flip around to the posterior hind foot just for a quick evaluation of the Achilles tendon. So we can see on this right image here, this is Achilles tendon in long axis with proximal to the, I'm sorry, with the calcaneus on the right, proximal to the left here. So that all looks normal there. We can see Achilles mid substance here on the left and then the correlative view in short axis down the bottom here with that normal hyperechoic, fibular broom end appearance of the Achilles tendon here. So that all looks great. And then finally, we'll comment on any retrocalcaneal bursa or retro Achilles bursal pathology fluid and whatnot here. So for this patient, Achilles tendon is intact. And I'll comment both on the mid substance and the insertion, both of which are normal in appearance and then no fluid within either bursa. We're almost finishing up here. So this is a general template of my ultrasound report. And I think, you know, anybody who's watched a couple of these lectures, a lot of us do this a little bit differently. I don't think there's a wrong answer at all, as long as you're comfortable with, you know, how you convey your information, as long as you're consistent. So for me, this is pretty standard, you know, whoever refers the patient, where we did it, it's what we're looking at, what type of exam, the machine that we used it on, the frequency, I'll typically use a 14 megahertz linear for my plantar heel scans or plantar hindfoot scans, you know, what side we're looking at, if there was any prior imaging and then my findings. So I've already gone over this. I'm not gonna reread all of this, but Kentaro mentioned this, I think it was last week, you know, for me and my findings, I will more often than not, sometimes I get lazy, but more often than not, I will just describe, and I've gotten better at this. I used to cheat and be quite lazy, but I've started and become better at really just describing what I see in the findings and not making calls in the findings. And then in the summary, you know, if we're talking about focal, you know, hypoechoic heterogeneity in the findings, you know, what the heck does that mean in the summary? So for me, that's plantar fasciosis. So my summary is really kind of giving a specific diagnosis to what I am describing in the findings. And I think that is helpful because a lot of referring providers, they don't wanna read any of this up here. They don't really care if there's, you know, if it's hypoechoic or hyperechoic, or if it's edematous or whatever, they just wanna know what it is and what the deal is. So I think the summary is helpful for them to be able just to skip all of this and just see, you know, what the heck is going on. So in this patient, after going through all the findings, there's clearly plantar fasciopathy, you know, with this plantar fascia fibroma as described above. And then, you know, since there is some overlap with, like I said, some of these tibial nerve abnormalities, I will comment that there's no evidence of any tibial nerve pathology. But I think, you know, bottom line here, just being able to really convey what you see on ultrasound is initially challenging, especially coming out of fellowship. That was one of the hardest things for me was, you know, I learned how to take a picture of the plantar fascia and of the calcaneus and so on and so forth. But then trying to explain that to somebody else in a report, I think takes a lot of practice and is a critical part of all of this. So that is what I have. So I think we might have a minute or two for questions. So thanks, everybody. Ryan, that was great. That was comprehensive, but also practical. One question for you, you know, one of the challenges I have sometimes is distinguishing between a, what I call a mid-substance plantar fasciopathy, meaning, you know, thickening, you know, that you showed versus a fibroma. Do you have tricks on helping to distinguish between the two? Yeah, I mean, you know, I think for me, I'll primarily look at plantar fascia at the calcaneus first. And what I've seen personally, you know, and somebody who has both, and this is not the case all the time, but you know, you'll see focal thickening at the calcaneus. And then more often than not, you all see somewhat normalization of that fascial thickness and fascial echo texture. And then again, kind of focal ballooning distally. And, you know, if I don't see any sort of pathologic changes, you know, right at the calcaneal origin, and it's, you know, a millimeter or more off the calcaneus, I think I'm more inclined to call that a fibroma versus, you know, true central cord plantar fasciopathy or fasciosis. You know, I think it's a bit of nuance, at least in my practice, you know, I'm probably gonna treat them somewhat the same, but yeah, I think just for me, it's the presence or absence of focal pathologic changes, specifically at the calcaneal origin is gonna make me kind of lean one way or the other as to whether or not I'm calling this, you know, fasciosis versus a fibroma. Yeah, it's hard. You know, I've learned over time that fibromas that are not full thickness, you know, they tend to form on the superficial portion of the central cord and spare the deep portion. And you can still see some of that fibular echoing texture, you know, through the deep cord, which would be more confirmation of a fibroma versus, you know, fasciopathy involving not the insertion, but the mid substance tends to be a through and through with loss of, you know, the normal fibular echo texture, but it's tough. Just- One other thing I would add along that line is if you see multiple, then you pretty much know it's a fibroma. And if you're trying to decide, you know, you can certainly look at the other side as well, because fibromas often are bilateral and come in multiples. And so, you know, continue to scan out distally. And if you see, you know, two, three, four thickenings, then that's really helpful as opposed to the single abnormality that you may be questioning, whether it's, you know, a partial tear versus the fibroma. In the young athletic population, you know, in our runners and such, we'll see those changes a couple centimeters distal to the calcaneus. You know, at least I will often more there than I will back at the calcaneus, or at least, you know, as common. And that's, you know, just trying to distinguish between what's a, you know, a partial thickness subacute tear versus a fibroma can be challenging. And that's where I think looking for, you know, for evidence of another nodule, you know, is really helpful in those cases. Yeah, good point. You know, Ryan, your protocol is thorough, and it reminds me that I should probably, at least in a minimum, have the distal plantar fascia, I mean, I'm sorry, the distal Achilles as part of the protocol, which I don't. I do have just one short axis view going across the intrinsic, you know, the foot muscles. So I do get the ADM, the FTP, and the quadratus plantae, just one single view. And as you mentioned, you know, part of our protocol is at least a long axis view with the insertion of the lateral cord, because, you know, when people have plantar fasciopathy, they tend to walk on their lateral foot because the insertion is medial. So we often will see concurrent, you know, enthesiopathy to lateral cord. And as you mentioned in your talk, Ryan, I always put, you know, there is or isn't pain with sonopalpation because they may be asymptomatic. And then make sure I follow that lateral cord to its fruition onto the, so the lateral cord originates on the lateral aspect of the medial tubercle, not the lateral tubercle, the calcaneus. And so I will always follow that back to it because, you know, if that's involved in your planning a procedure, as you know, you got to make sure you get lateral enough to also incorporate that. So, yeah, I would, the protocol is very thorough and it doesn't take that long, but you, you know, got it all in there. Yeah, and to be honest, you know, I, in the past, you know, evaluation of the Achilles wasn't always in my protocol for this. You know, in some patients I don't do it, but I've just, I've had a couple of times where I've been fooled. And I think for all the world of plantar fascia and then the plantar fascia looks okay, and we look at their Achilles and they've got this insertional stuff going on. So I've been, you know, kind of more inclined just to double check my work and make sure we're not missing something. Sure. Well, that was, again, these will be posted on the AMSSM YouTube channel to go back and take a look at these. And so, Ryan, thank you very much. And again, the next, the next case series will be in a few weeks and we look forward to seeing you. Thanks, Doug.

3rd Edition, CASE 17

3rd Edition

Foot

plantar hindfoot pain

ultrasound diagnosis

plantar fasciitis

nerve entrapments

fat pad issues

diagnostic protocols

ultrasound imaging