• LecturehallMSK Ultrasound not Just for Fascia
  • Lecture Transcript
  • TAPE STARTS – [00:00]


    Male Speaker: So my interactive presentation is a little different. There are some clicker questions, but there are some open-ended questions as well. And so, feel free to shout out. And in fact, I want to start with an old-fashion raise, raise your hand. The question is how many people, keyword here, routinely use ultrasound in the clinic? How many out there routinely use? And routinely meaning daily. Okay. Good. Let’s talk about that. Let’s see maybe if we could bring up the reasons why and maybe overcome the hurdles of bringing it in into the clinic. Let me see if I have my laser pointer, good. I need that. No financial disclosures, learning objectives. All right. So first question here is, which of the following is the most prohibitive factor when deciding to incorporate ultrasound in clinic? Is it initial cost? Is it lack of training? It takes too long in the clinic? Reimbursement? Limited utilization? Ah, that’s interesting and it makes sense. So it looks like the lack of training is winning out. Okay. So I want to talk about each one of these. I’m going to really concentrate on the bottom because I think that’s the key. And that’s what I see when I do the workshops is there is a lack of understanding and rightly so of how much the ultrasound can help you in the office? In other words I think, utilization is look that is narrow and we need to broaden that. So ultrasound hurdles cost, training and benefits. How much do you expect to invest in purchasing an ultrasound? Some of these are leading questions. So, yeah, well, take a guess. Excellent. It’s good that people are staying away from the 5,000 and the 40,000 and I’ll talk about this. Good, okay. 20,000. First thing is what do you need in an ultrasound which is critical, you need a good image, right? If you’re not getting a good image, you’re not going to use it which goes back to utilization. So you need high frequency. You don’t want to be low frequency. What’s high frequency for foot and ankle? You need 12 or better. 12 MHz or better which means it’s going to be a little bit more costly. But if you go lower than that, you’re starting to hand cuff yourself in utilization. You’re not going to get the best image. We need high resolution because – I’m sorry, we need high frequency because we need to see small structures and so it’s important to have that high frequency. So 12 or higher and most of these probes are multiple frequency, meaning, that you have a range. 10, 12, 15, 12, 15, 18. All right? So you do have some versatility and some range that you can work with. You need Doppler. And it used to be that this was $5,000 extra. It was an add-on. Now they’re pretty standard with the Doppler. And you need color Doppler because we use vessels for landmarks to find structures. We also need them to see if you’re doing a guided injection if there’s a nearby vessel or if you have a soft tissue mass that it’s – there’s a vessel associated with it. So that’s important. And you need a power Doppler because it’s very sensitive. It picks up inflammations so you can see hotspots on the tendon where there is neovascularization. And you need pulse Doppler because now you have an arterial Doppler in your office. Now you can assess pulses, now you can assess the wave form, right? It can help you with your ABIs, so once again, increasing utilization. Warranty would be nice if you’re buying used, sometimes that’s not available. And then training and setup would be nice. A big question I have is, okay, there’s a lot of buttons on these ultrasounds. I don’t even know what to push to get the best image. Well, that will take about 15 minutes to show you. All you need are four features and you’re at 95% to 98% perfect image. You can leave everything else as a pre-set as it came as – it came in box that way. So frequency needs to be high, of course. You need to be at proper depth which is just a one-push button, one centimeter, two centimeters, however deep your structure is, be at appropriate depth that’s going to increase resolution. Focus is just a marker on the side of the screen. You want to be in line with the structure. If your structure is at the top of your screen, you bring that indicator up to line up with it that increases lateral resolution.

    [05:02]

    And then gain is just the intensity of the ultrasound which is overused. If you’re doing the first three, the last button gain, it doesn’t even have to be. I hardly use my gain because everything else is set. So a case. A 43-year-old male presents with three-week history of ankle sprain, curve while hiking in Oregon, pain swelling, can hardly step on the foot after three weeks. X-rays were negative, he hadn’t taken there. I took him when he came back in town. Clinical exam shows pain with palpation over the medial mid-foot. All right. So we’re all thinking Lisfranc. What’s your imaging of choice? CT scan, MRI, excellent. Okay and I agree. MRI is the standard imaging. You got 94% sensitivity, 74% specificity and 94% predicted value. That is the gold standard for Lisfranc injuries, right? We know how many remiss. We see those from the ER, always – lots of false negative radiographs. And they occur quite frequently. One in 50,000 cases per year. So if you look at the Lisfranc out of the Sarrafian anatomy book, it really is a complex, right? So the blue represents the interosseous ligament which we’re all aware of in regards to Lisfranc injury. The green is the plantar connection with the Lisfranc complex, and the red is the dorsal connection, right? And so, ultrasound is not going to show us interosseous because it can’t go through bone. You’ll never the interosseous ligament on ultrasound. The plantar portion is really a waste of time. It’s hard to see it and a lot of time it’s spared in Lisfranc injuries. But the dorsal ligament correlates to the interosseous rupture or can correlate the interosseous rupture and that is readily seen on ultrasound. Easy, and I’m going to refer to easy ultrasound exam and I refer to how easy it is to find and how quick. These exams need to be quick, right? There’s two codes, right? The 76881, which is our $100 reimbursement, that’s a full ankle survey, and there’s 76882, which is your site-specific short exam. It needs to be short. And I can tell you, the last year, looking at the numbers, 90% of my ultrasound scans where the short scans, the 76882. It’s a work horse in the clinic because you got to fit it in to a busy clinic. And so, these exams should be three minutes, that’s it. At the most, three minutes, a lot of times for 30 seconds. This can be easily seen, one minute, you’ll be done and you have an assessment of the Lisfranc ligament. So let’s see how it’s done. Based on literature, two great studies, we’re looking at a coronal scan, frontal scan of the forefoot, right? And that’s another thing about ultrasound, be putting in these side points about ultrasound as we go through. The other thing is that ultrasound is not limited to the cardinal planes. You know, you don’t have to – you’re not in the sagittal, frontal or transverse like in MRI. There’s two ways you look at structures with ultrasound, the long axis and the cross section. It doesn’t matter how that structure is running in the body if it’s going the sagittal, the coronal, picking up two planes, it doesn’t matter. It’s the frontal and the cross – I’m sorry – it’s the long axis and it’s the short axis which is the cross section. And so with coronal scan, high frequency, one-centimeter depth focus. And you’re going to get a good image of all those things there. And so I’m going to jump this slide and go to this one to show probe placement. So here is our starting point here. And so our probe is this way, right? This is where we start and what we’re going to see is the curvature of metatarsal 1 and metatarsal 2. Then we go proximal and the key is that metatarsal 2 never goes away in your image. If you lose that, you’re wrong because it doesn’t go away. It projects back further proximal. Metatarsal 1 will end, and you’ll have a black space on the ultrasound. The next bone is picked up is the cuneiform and that’s where your dorsal ligament is. It is so easy to pick this up. And so we see that this is our dorsal ligament, all this. Here’s the superior portion of it, right here, but it fills it all in. Here’s our space. This is a little shelf coming off the cuneiform. It’s not a bone fragment. So you’ll look at that and you’ll look at an injury to the dorsal ligament. And you look if there’s actually a diastasis as well.

    [10:03]

    There’s separation. This is easy to see. Here is – oops, sorry. Here is the space, not compromised, but this ligament is distended. It’s concave and you have a loss of the normal architecture. So this is a Lisfranc injury without separation. If we look at our two pictures, normal, abnormal, no separation. There’s a high correlation between this and the dorsal ligament and the interosseous ligament. So you look for the normal looking ligament. It should be about one millimeter meaning one millimeters this way. You look for the space which should be around one millimeter and literature shows that when it gets over 2.5, there’s a rupture in the ligament. Easy exam, three minutes at the most. Calcaneal process fracture, anterior, superior, calcaneal process fracture, typical inversion sprain, lots of times, there’s no radiographic signs of the fracture. Of course, we have the bifurcate ligament associated with it. And with ultrasound, we’re going to be able to see the bone, the process and the ligament and assess both. So here’s a medial oblique projection showing, obviously, a fracture in this case. We don’t need anything else. We have it on x-ray. But for those ones that we don’t have on x-ray and this is a manipulated slide to show you probe placement, here’s our process. Bone is very hyperechoic. It’s going to be bright white. Here is our ligament. Ligament and tendon are going to show that fibular collagen fiber architecture. Ligaments are going to be more compacted, tendon a little bit wide, wider. But you actually see that dense regular connective tissue parallel alignment. And then we see our cuboid right here. This happens to be an accessory bone, right? Right here is my patient and the fracture that was not present on x-ray so here we have normal. We have the process. We have the cuboid and we got our ligament running right here. Here we have the process. We have a bone fragment and we have the cuboid and we have the ligament as trashed basically. So that can be picked up and again at a very efficient scan. You got to fit it into practice if it’s going to work and it can be. In my perspective, I do teach medical imaging at the Arizona School of Podiatry but that’s part-time. My fulltime is private practice. And so my perspective here is how it works clinically. Is it worth the cost? Can I fit it in the clinic? Does it make some kind of money? Is it good for patients? That’s my perspective with ultrasound, not academic but clinical. Case. 23-year-old nurse snowboarding in New Hampshire, injures ankle. Urgent care of diagnosis, lateral ankle sprain, nothing on x-ray. She comes home. I take more x-rays, nothing on x-ray but she has pain with palpation at the malleolus and the lateral talus. Happened to be I read an article one week before she came in and I wish they all work this way about snowboarder’s injury in lateral talar process fracture, right? One week I get a patient that comes in, I wish, again, they all work that way. So what special imaging would you order? Yeah, and I agree MRI-CT makes perfect sense. Okay. Snowboard injury, typical ankle sprain, negative radiographs in over 50% of cases. You got your types which we won't get into. So compression type of injury. It affects different structures, different joints, but the key here is what can the ultrasound do for us. There is our probe placement and anatomically you look for bony landmarks, right? So with this probe placement, you’re going to see the malleolus, bone number 1. You’re going to see talas, bone number 2, and you’re going to see the calcaneus, so that should be in your image. This is – this slide is manipulated so you can see it in regards to an anatomy. But here we have our lateral malleolus. We have our talus which is in two pieces and we have our calcaneus and that is a fracture, a very efficient scan, again, less than three minutes. And with documentation, you have your template.

    [0:15:00]

    You fill in the gaps with the template. That should be quick too. So this should not be taking too much time in the clinic. This is my picture. This is not manipulated. This is how you would see it on the ultrasound. There’s our lateral malleolus. Here’s our talus. Here’s our fragment piece right here and calcaneus is down here. So I only read this one week prior so I'm thinking am I actually seeing this, right? So I get an MRI and that’s what it was. Case. 45-year-old male represents with forefoot pain, injured foot. Wow. Two being down the river, slammed his foot into a rock. I don’t think he felt that much but ended up with pain for six months. He came to see me. X-rays were consistently negative. Pain at the second MPJ. So what’s all the things that this could be? It could be plantar plate. It could be an injury to the joints, right? It could be stress fracture. It could be lots of things, right? Forefoot pathology. One of the hardest things I think clinically is this differential of forefoot pathology. It’s this long list and it can be difficult. And the ultrasound – and we’ll get to this – the ultrasound can help a lot. So this was – he could not afford an MRI. They wanted to do an MRI, but he had such a large portion to pay, he could not get the MRI, right? So I did an ultrasound and what we see here is we see the second metatarsal head. We see the proximal phalanx and we see the joints. Here we see a large effusion, e for effusion, fluid in the joint and we have this step-off as it’s called, disruption of the cortex. He has intra articular stress fracture of the joint. Now, the thing at this point is six months. I want to do a bone stimulator. So the company comes back and says, “You don’t have x-ray.” Evidence of it. We can’t do it. He needs to get an MRI, so now we’re back to he needs an MRI. So there’s a long process but finally they accepted my ultrasound and got him into a bone stimulator and he did fine. 40-year-old female patient with posterior calcaneal pain, no history of trauma, there is a focal point of pain right at the posterior calcaneus. Ultrasound showed nothing wrong with the Achilles tendon. X-rays were negative. But what we did see – here’s the x-ray. What we did see is this early spur formation at the calcaneus and a big tool to use and I tell my students this and the residents this, with ultrasound, is using it to palpate. That’s huge. Now, you have a visible palpation tool. It hurts right there. What’s there? And we look at the screen. And that’s exactly where she hurts. So early spur formation not seen on the radiograph. Little review may be a little tricky. Which of the following cannot be easily assessed on ultrasound? Yeah, exactly, the interosseous. We just said that. It can’t go through bone. Ultrasound cannot get through bone. Okay, this is a leading question. So take your guess or maybe you know it. What is the average special resolution of high frequency ultrasound? I remember it’s like golf here, there lower the better. Lots of people pick and see. Okay. All right. So, 0.15 to 0.3 is actually an MRI. D is ultrasound. The key – the point of this question was to show how comparable the two are in regards to resolution which a lot of people don’t realize and that’s why radiologist who are very adept at ultrasound and very adept, of course, at reading MRIs will pick ultrasound for tendon pathology because of the resolution and because of the other stuff that ultrasound does for us like being able to move the tendon in real time which we can’t do in the MRI. So if you get a radiologist who likes both, they’ll tell you, “I really like…”

    [0:20:00]

    Especially picking up chronic tendon injuries, tendinosis and we’ll see that in the picture in the few slides. So normal Achilles tendon, so here we have calc – this is long axis. So here we have our calcaneus, here we have our collagen fibers, fibular – nice fiber architecture running down. But then we have this dark space here. And this is – one of those side points I’m going to bring up with ultrasound is that ultrasound waves need to hit the structure perpendicular. So the probe has to be parallel to the structure you’re attempting to visualize. And so as the tendon dives deep to insert on the calcaneus, you lose the perpendicularity. So you need to rock the probe, right? Which sounds like Friday night thing. Rock the probe, right? And that will go away. So that’s a normal tendon. That’s not a normal tendon. Down here looks pretty good but we can see, you know, here’s the peritoneal and up here we can see all the space right here, right? And we can also see that you got this concavature, you got this widening of the Achilles. Really easy to see. This is not normal. We got a lot of fluid which is the black running through our tendon. Here’s the posterior calcaneus. Here’s a nice picture of the PT tendon. You can see that fiber architecture but look this is normal down here. So this is the sheath right here. But look at the distension of the sheath and all the fluid in it right here, but this is the critical thing. This is why I love this slide. Look at the loss of fibular architecture right there. That’s that resolution power that the ultrasound gives you. It can pick up a loss of normal, fibular architecture and so you see chronic tendon problems on the ultrasound. This is a short axis so now we’re looking at the oval of the Achilles tendon. And this is a very large bursa. This is just a lot of fluid and so it prompted me to do an arthritic panel and she had a sed rate of 80 and a rheumatoid factor of over 200. So this was the onset of her rheumatoid arthritis and, of course, a referral to the rheumatologist. Spring ligament. So not only can we assess the posterior tibial tendon, but we can also look at the spring ligament but just one portion of it, right? And it has a high correlation with MRI in regards to the one portion. And that portion is the superior medial portion which happens to be the widest and strongest part of the spring ligament. Can’t see the other two parts of the ligament. MRI is good for all three of them but we can see that with visibility, ultrasound is just as good as MRI in picking up that portion of the spring ligament. So the only reason I bring – I brought in a picture of anatomy is to show you the relationship here between the PT tendon and the spring ligament. The PT tendon is going to be a landmark in finding the spring ligament. And since you’re going to be looking this way. Right here in this – the probe is going to be oriented this way. This is going to be the cross section of the PT tendon. So it’s going to be oval. And it’s not going to come in very good because you’re not concentrating on this. See, with ultrasound, a lot of times you can’t pick up the whole field. You have to be – you have to like – a good example of that is the peroneal tendons. You can’t look at the brevis and the longus as one unit. Usually, you have to focus on one and then focus on another one, alright? And so – but this becomes a landmark. We know that spring ligament runs underneath it, right? So here’s our PT tendon and there’s our spring ligament. And when that’s injured, it’s not there, alright? Now we have the tendon sitting right on the bone in the spring ligament. It is attenuated, right. Sometimes you are not even visible anymore. And here’s another picture of that. Right there with a lot more fluid and the PT tendon is a lot more pathologic. So spring ligament, PT tendon can be assessed on the ultrasound. As I was mentioning four-foot pathology. One of the things that I – is not high on my list for ultrasound is Morton's neuroma and students and residents will tell you that I always emphasize this. When a neuroma is in its early…

    [25:00]

    …formation, it really is just a compressed nerve, right? And the ultrasound does not pick that up right away. It does once you have fibrosis and scarring, and the bump and you have a Mulder's click that you can hear down the hallway, you know, and the scream when it happens. In other words, the ultrasound can really pick it up well when you don’t need it anymore. When it’s early it’s not that great. And so, when students come in and they rotate through my office and they say, “You know, I have someone with a Morton’s neuroma or at least I think it is and are presenting to me.” And when I say, “Well, let’s get and ultrasound,” they’re like, “wait a minute”. In class, you told us you didn’t like it for neuromas. Yeah, but I like it for other stuff. Plantar plate, early stress fractures, showing effusions, all that other pathology that could be occurring. And so, with the plantar plate, there’s a little bit of manipulation with this. You got to do a little bit of movement because of the parallel. Remember that ultrasound has to be perpendicular. So sometimes, you got to maneuver the toe, the proximal phalanx, and the metatarsal so that plantar plate is going straight across, parallel with the probe. It’s not hard. But it’s really – it’s a layered thing that you’re looking at. You got your metatarsal head and then you got your hyaline cartilage, which is black on ultrasound. Then you can jump up and see the nice fibular architecture of the FDL. And if there’s any confusion, you move the toe and you can see the FDL moving, right? In between is the disorganized connective tissue that makes up the plantar plate. And so you manipulate that and try to find its insertion on the proximal phalanx. And when you can’t find the insertion, then you have a plantar plate tear. Very clinically rewarding when you go in with a differential of three or four things and you walk out and you know what it is. And again, an efficient scan. Maybe a little bit more practice with this one to get it, but an efficient scan. And if you talk to the best sonographers out there, they’ll tell you that the difficult part for foot and ankle is the anatomy, which is not our difficult part, right? So the hurt – so you’re already there, in regards to knowing this, you know. The ultrasound piece is just a little extra. Knowing your anatomy is the key things for all imaging. Pain times three months left leg, shooting, burning pain, anterolateral left leg, no inciting event, worse with ambulation that can ache off and on, doesn’t have to be weight-bearing for it to hurt. And so, already you’re thinking – I was thinking superficial peroneal nerve entrapment where it pierces the fascia at that distal anterolateral aspect of the leg. You can read through this, but the key point here is no masses were palpated. And so, in my mind, clinically, it’s a nerve compression. Put a little steroid in there, try to calm it down, see how it does. Ultrasound, which took all of 30 seconds to do, short axis of the nerve and you can see these little oval anechoic, lack of echo dots in there. The typical – the description that’s used or the term that’s used to describe this is a honeycomb appearance. And basically what we’re seeing is, is the fascicles. We’re seeing the bundles of nerves in their fascicles wrapped with the perineurium wrapped around it. And so what we have here is this partly compressible mass that’s right on the nerve that ended up being a schwannoma. It was not palpable clinically. Gout. Normally you’re going to see the fluid in the joint which we’ll show in a couple of pictures here, but you actually can see the crystals wind up in the joint. It’s going to be what’s called a double contour sign. Meaning that you have the hyperechoic contour of the normal metatarsal head and then you have another one right above it that follows the same contour. Those are the crystals, wind up along the metatarsal head. You can see pictures of normal gout, right? Normal gout. And of course you’re going to see the large effusion fluid within the joint. You can also see early erosive changes that are not seen on X-ray.

    [30:00]

    So here we have a large erosion in the metatarsal phalangeal joint that was not readily available or readily seen on the X-ray. Which of the following soft tissue masses is the hardest to diagnose on ultrasound? It’s a leading question, take a guess. So we got fibroma, we got lipoma. No one’s picking ganglion. I think we all know that ultrasound’s great for ganglion. Okay. So the answer is lipoma. The most common soft tissue mass in the body, right? Why would that be? I mean it’s – you can usually see those. Why can’t you see them on ultrasound? It’s because they’re fatty. And so the tissue in the mass is very similar to the tissue outside the mass, and so you don’t have contrast. You have very little contrast between the two. Also, lipomas can have very thin capsules that are really hard to see. So lipomas are not that easy to see. However, the rest of these, ultrasound can readily see them. So, fibroma. Typical fibroma coming off the plantar fascia. Fusiform appearance, usually hypoechoic, not as bright white as the surrounding structure. And you’d be surprised how many of the – how many fibromas are not readily palpable clinically when they’re proximal. You know, I’ve had patients where I’m just looking at the plantar fascia, there’s no palpable masses and there is a fibroma sitting at the proximal arch that I had no idea was there, unless I did an ultrasound. So, typical appearance of a fibroma – hypoechoic, fusiform, nodular thickening of the plantar fascia. It will be attached to the plantar fascia. This says our patient because this was a grand rounds I did with a resident. So here’s your typical and this is our patient that had septated pattern within the fibroma. This now becomes atypical. And very similar to a possible fibrosarcoma. It was not – got an MRI, thankfully it was not, and so the ultrasound could never tell us definitively that it is or not but it can tell us it’s atypical which prompts us to do a little bit more investigating. Again, a very efficient scan. We know about fibrosarcomas. You’ll see – you can see increased vascularity which brings up a little discussion on soft tissue mass. So ganglions, synovial cyst, whatever mass that you have, the ultrasound gives us the size, or if we can’t measure it because it has finger-like extensions and it’s going everywhere, it tells us that it has finger-like extensions and it’s going everywhere, right. It can tell you if there’s vessels associated with it, either adjacent to it or feeding it, right. It can tell you if it’s completely fluid-filled or partially fluid-filled or not fluid-filled at all which is, I think, critical clinically because if I have something that on ultrasound I think can’t be drained, then that now is no longer an option. And I don’t put the patient through an attempt to drain it. And of course you can drain it under ultrasound guidance which is very cool and very good, very efficient. And then you have the intangibles with ultrasound too. I always have the patient watch. I always have that ultrasound positioned so that the patient can see me – see the examination, see the aspiration, unless they don’t want to, right. And so that intangible of communication to the patient and the fact that you’re using technology on them, I found that folks like to know that you’re using the newest technology on them and that you’re doing all that you can. Twenty-three-year-old soccer player with one-month history of left foot pain at medial arch, some shooting electrical pain in the arch. It happened when he – during a game when he did a kick, felt something pop and then it had been hurting for a while. X-rays were negative. And so, on the right we see a normal abductor hallucis muscle and then we see his on the left.

    [35:06]

    And so he injured that abductor hallucis muscle. And one month later, I had a female soccer player came in with the exact same injury. Another view of normal, abnormal. And then a 65-year-old diabetic with sudden onset of swelling, warmth, redness, pain in the dorsal forefoot. Of course, we know the differential here is cellulitis, Charcot, you know, and anything else that you can think of. And so how can ultrasound help with cellulitis? Is there an abscess with the cellulitis? Which I think is very important to know. Am I dealing with cellulitis or am I dealing with an abscess with cellulitis? And the examples that I have shown up to here shows ultrasound to be very, very highly sensitive. For instance, plantar plate. Studies show that in picking up plantar plate injuries, over 90% is sensitive for that, right, which is comparable to MRI. Not specific. If you need to get specific, on what part of the plantar plate, et cetera, if you want to get specific, that’s an MRI. But ultrasound is extremely sensitive, which is what you want in the [trenches] [36:28], right? In the clinic, you’re trying to whittle off that differential diagnosis. You’re trying to pinpoint what’s going on. And so, having that – and again, three-minute scans to be able to get more precise about your diagnosis, you want something highly sensitive. And so, no, ultrasound is not very specific for things except this – 90% specific. If you have the environment of a cellulitis, and right underneath it is a mass, it’s very specific for an abscess, right. And so in this case, it is specific. But it’s just – this was the last case. I’ll just kind of summarize things here. The sensitivity is important clinically. And so you need to know what the ultrasound can’t do and what it can do. And what it can do in three minutes is give you a lot of information to help your patient. And if you’re utilizing it, which is what I was focusing on, if you broadened your utilization of it, and you can see what it can do and more than this – and we haven’t even touched on guided injections which is a whole other lecture, alright. But what it can do diagnostically, you’re using it five to six times a day, right, clinically, and you’re doing those short, specific exams, that adds up and it will pay for itself. It usually pays for itself in six months, right, if you’re using it the way you should. And it will give you something on your bottom line, right. It’s not going to get you rich. Ultrasound is not going to do that. But it helps you clinically with that tremendous sensitivity of picking up things and it does help the bottom line. So any questions, I’d be happy to entertain. Good. Thank you. I appreciate it.


    TAPE ENDS - [38:20]