#66 - Bone Stress Injuries: The Good, The Bad, and the Ugly with Dr. Tyler Kemp, Part 1

Hi guys. Welcome to another episode of The Factor Podcast. I'm your host, Jessica Riddle. If this is your first time tuning in, welcome and thank you for listening. Today we kick off a new 2-part training titled Bone Stress Injuries. The Good, the Bad, and the Ugly with Dr. Tyler Kemp. Now, I don't know about you, but when I hear the phrase bone stress injuries, there is absolutely nothing good that comes to mind. In fact, it serves as just another reminder for me why I am not a long-distance runner. If you put me on a Peloton bike, I can ride for 50 miles, no problem. But if you see me running outdoors with any kind of speed, It's probably because something is chasing me. And I can't imagine that I'm different from a lot of your patients who are active recreational athletes. I regularly work out 5 to 6 times each week, but inevitably, there are times that I push too hard for too long, or I use bad form and end up with a nagging injury. Stress fractures are actually quite common. But did you know that there are different subtypes of fractures that can vary depending upon the mechanism of injury and the location? Did you know that females are more likely than males to suffer from bone stress injuries? We will cover these topics and a lot more on this episode and the next, including the different types of stress fractures, the importance of imaging for accurate diagnosis, and a grading scale that you can use for neck injuries. Our guest instructor for this training is Dr. Tyler Kemp. Dr. Kemp is a chiropractor practicing outside of Cincinnati, Ohio. He has a passion for working with athletes and clinical interests in treating tendinopathies and bone stress injuries. He utilizes joint manipulation, rehab, and acupuncture in his patient care. And while his daily practice involves treating a diverse range of patients, the office's focus on athletics has allowed him to specialize in treating bone stress injuries commonly seen in runners. Alrighty guys, today is gonna be an episode chock-full of great information that you can implement into practice. Right away. Let's get started.

Well, thank you, Jessica, and thank you guys for joining me. So quick background about myself: I am a chiropractor by trade. I practice in a sports medicine style multi-doc office outside of Cincinnati, Ohio. I've been really fortunate to work with. in a number of settings and see a lot of different patients, and that has made me interested in working with athletes. That's not primarily what I see day to day, but as a chiropractic office that sees a lot of athletes, we naturally see a lot of runners, and a number of runners do deal with bone stress injuries. So we'll talk about a number of things about what treatment, management, and stuff looks like in our, in our chat today. So loose outline, we'll go through some things with the anatomy and define a few terms, what risk factors and features of will look like. And then kind of on the second part, and frankly a little more importantly, we'll talk about some return to sport rehab and things like that. Because it's great if you can catch these injuries, it's a lot trickier to get them to frankly where they need to be on the back end. So by, by the end of this, I want 3 things to happen. One, you to have an idea of how to identify a stress fracture early. choose the right type of imaging, and then finally have an idea of returning them to their sport, their day-to-day activity, or back to running in general. So first we need to define a few terms. So what is bone itself? What is, what is a stress fracture? So we need to think about bone as a dynamic living tissue. It's not just the framework that our muscles and joints kind of hang off of. It's active. So We're always dealing with, going back to physiology in school, the, the process of building up and breaking down of bone. So we have our osteoblasts, those cells that build bone back up, and osteoclasts, those that break it away. And it's always this constant back and forth. The problem we run into is when we're breaking down more than we're building back up. It's no different than if you spend more than you make, you can use credit cards for a while, but after that it gets a little tricky. Unfortunately, our bone doesn't have a line of credit. It's going to run up what I like to call a bone debt by starting to lay down less quality or less good level of bone, and that's going to cause an issue as somebody's active and continues to progress. So the loose definition for a BSI is an overuse injury due to an imbalance of excess bone damage and inadequate or lack of time for repair. So Specifically, this exists on a spectrum. So on the far end, we have our stress reaction, and on the other end, we have a complete fracture. And so on the far end, we have our stress reaction. That's where we're starting to see the lack of response to load. We were starting to see things like a periosteal reaction— that connective tissue layer starts to get irritated. As it gets worse, we have the stress fracture where we actually start to form We start to form a fracture line within the bone. And specifically, bones are generally 2 broad types. We have the cortical bone, the outer portion, that kind of thick area, and then trabecular or spongy bone. In a stress fracture, we're starting to actually start to form that fracture into the bone. And then on the far end, the area we never want to go if possible, is complete fracture, where we have had so much accumulated trauma that—

Right.

That bone is so weak, it's fracturing through. And that's where you get into some really messy things such as displacement of bone fragments or the associated joints. So if we can avoid that, that's going to be pretty crucial. So I wanted to make this a little practical. So this is a case from a local high school athlete. They had some issues at the end of their track season where they had a, we'll call it a case of shin splints where they had to pause their training for a little bit. And then got better in about 2, 3 weeks, and then they had about 4 weeks left of the season. So they had this brief pause where they were out of training, and then they went back into it. And then cross-country is their preferred sport over track, so they started to aggressively increase their mileage over a several-week period to kind of prepare for the coming season. Over the course of that time, they started to notice this kind of deep, nagging hip pain. It was getting difficult just walking around home. It was almost impossible to run. And for those reasons and some things we'll talk about on the physical exam side, we ended up getting an MRI and it confirmed a grade 4 stress fracture of the proximal femur or the femoral neck. So it's great that we caught it, but as we go through, I want you to think about, we'll call this, this person Dan. How do you want to help Dan manage this injury? And then How can you, or what's going to be the best way to get him back to his sport in the next season? And things contribute— we'll use Dan as a stereotype, but there are a number of factors that contribute to these types of injuries. I call it the rule of twos. There's 3 parts to it, which is a little confusing. The 3 things are too much, too soon, and too little. So too much meaning too much load, too much Volume, things like that. Like, this could be the training mileage in their week, or it could be the number of like training sessions per week. Too soon, that's the frequency. So again, like the 2 a day going from 2 or 3 days a week to 10 days a week, the, the math doesn't work on that. And then finally, too little, meaning too little rest, too little time for them to recover. This is somebody who is just going back to back to back without creating any time for For buffer. And in a weird way, we got to see this with the COVID pandemic. So I'll use a high school athlete as an example. You can have somebody that might be playing year-round sport in some way, shape, or form, or a varied athlete. Maybe they, they do football in the fall, they do basketball in the winter, and they do track in the spring. So for most of the year, they have some amount of training stimulus and they have a pretty active threshold. The problem we had is depending on where you were in the country, From January to May, or even longer depending on where you're at, a lot of sports were shut down. And then it was kind of that slow return to normalcy that we saw in the fall. And a lot of it was a push to, let's at least get back to sports that are outdoors. Some of these things can be done safely. Let's go for that. And it was this huge disconnect of, you have these, you have athletes who've been training year-round. You suddenly give them a 6-month period where they're not really able to do any kind of activity. And then you're expecting them to return back to their previous level. So there's this, this huge gap, and we saw it a lot in that, that fall time, especially, especially on the runner side, because that's the stereotype of all these high school athletes coming in with a ton of these injuries because it was this huge disconnect of the training load and then the return to sport timeline. So hopefully we won't see a surge like that in the coming years, but it was, it was interesting. On the slide here, you'll see a brief study. This is a 2015, title is Epidemiology of Stress Fracture Injuries Among U.S. High School Athletes. 2005 and '06 to 2012, 2013. Big overview, big thing that came out was, was this. So 65% of injuries resulted in 3 things of these stress fractures. One, 3 weeks or more of time lost, medical disqualification, or the end of season. So 3 weeks of time lost, that they were out for at least 3 weeks. Medical disqualification, their season was over. And then finally End of season, meaning by the time they had gotten better, their season had ended. And nobody, nobody wants any of those things. So, and we'll go into this a little bit later on, but a lot of these injuries, depending on the location or the grade, that will determine your healing timeline. And it allows you to have a better, more frank conversation with the person in front of you about how long this is going to take. So who is kind of your, your stereotype or your archetype about who's going to come in with this injury? So One, there's a slight preference for female over male for a number of reasons. And then I've seen anywhere from 80 to 90% of all stress fractures occur in the lower limb. There are a handful of injuries that might come in the upper clavicle, scapula, humerus. They're fairly uncommon. So the majority of stress fractures are going to be basically below the belt from an anatomy standpoint. And whenever you have an active, generally a more active person come in, you need to have a few things that should tip you off that this is an issue. So I want you to think about playing the odds with your patient's exam and history. I'm not encouraging at all gambling with your patient's health or being unsafe or something like that, but thinking about what's the most likely thing that this is and how can I screen or how can I sift through to figure out if it's something else relatively quickly. And there's a number of historical features that are going to come in. One, they're, they're generally a runner, an athletic person, someone who's pretty active. They're not going to have a good story about what caused it. It's not a fall. It wasn't they got sideswiped at a game or something like that. It's just this random pain with no specific onset. Generally can be focal too. They will gesture to one area or they'll be able to outline it with their fingers. Another hallmark is they'll have pain with activity and then pain that'll stick around. So maybe they'll, they'll have pain during their run and then it sticks around for a couple of hours. After or even into the next day. And then be specific with your questions. There's going to often be recent changes in activity. I saw someone recently where super active runner, but they started added basketball in just wintertime and all that. And that has started to raise their suspicions for that just because they're already running a ton on their own. They're doing a ton of mileage and they're doing another activity in their week that just the demands of it for the bone debt. There's, there's only so much margin in there.

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And then moving on, we need to couch everything into the degree of risk. So I'm fond of the phrase do no harm. We want to have an idea of how can we reduce harm or problems with our patients. Now there's some things like risk factors which contribute. Those are broken into intrinsic and extrinsic. So intrinsic things we might not be able to change a whole lot— male versus female, their individual biomechanics, nutrition. Not saying that we can't provide nutrition recommendations, but if somebody doesn't have Adequate access to nutrition, that can be a tricky thing. And then extrinsic thing, their training program, their mileage, things like that, their terrain, whether they're being on asphalt all the time, the road, trails, grass, things like that. Variety is your best friend on that. And then finally, shoe style and wear. I used to be really into the exact biomechanics of the shoe. More broad principle is just look on the bottom of their shoe. If they've worn all the tread off, it's probably time for a new pair. And I think that's a real easy— Easy criteria there. And then continuing with risk, each region of anatomy is associated with a different level of risk. So on the higher side, well, high and low risk. So high risk is defined of the odds that there are increased odds of there being a progression of the injury, failure of conservative care, or the need for surgical intervention. So the high-risk areas include the anterior tibia, The femoral neck, and then the sesamoid bones. The low-risk: metatarsals, posterior media tibia, fibula, femoral shaft— different than the femoral neck— and then the sacrum and pelvis. So based on these areas, you can start to build out the timelines of what's the recovery, what's the healing going to look like overall. So have the— have this list in your head, especially if you see active people. So what is, what's your physical exam going to look like? Do the good stuff, range of motion, palpate the area, ask the patient to show you where it hurts, have them walk, have them run. In some really further progressed cases, they're going to have a really hard time weight-bearing. One of my favorite quotes is from one of the local high school coaches. He says, no high school kids should be limping. So if you have a young athlete come into your office and they're, they're limping, It's probably something more concerning. It's probably not a simple sprain strain. And then there's some orthopedic tests you can do. Now, specifically, there are a number of different tests you can do for stress fracture. One of the most common ones that's helpful is the hop test. I know it seems silly, but have them hop on a single leg, affected side versus unaffected side. If that is enough to induce pain, some kind of bone injury needs to be on your radar. And then practically, if it hurts just for them to hop 2 times on your office carpet, it has to be much more painful or much more problematic for them to be just pounding it over the course of mileage on the road. So once you have a patient that you're concerned about BSI, we need to figure out if there's going to be the need for imaging or what, what's appropriate imaging. So there's a lot of different options: X-ray, MRI, CT, ultrasound, things like that. When we're— when we order any image, we want to think about the value of that test. So the 2 terms I want to bring out are sensitivity and specificity. So if a test is very, very sensitive, that means if it's negative, we can confidently rule that out. If a test is very specific, that means we can rule something in. So if we're going to be trying to rule out a stress fracture, We want tests that are a screening tool that are going to be very sensitive for allowing us to cross that off our list and move on. Let's talk about x-ray real quick. So pretty cheap, pretty easy access in most offices. You might have it in your office or you might work in a group where you can walk the patient down the hall. The problem with the x-ray is it's very specific. There's always something you might see. You might see some subtle change. It's not very sensitive. And the problem is A lot of these, when they're lower grade, a 1 or 2, it's out of a grading scale of 4. 1 or 2s can often be undetected on x-ray. I've seen a couple figures where essentially unless it's a 3 or more in terms of the grading scale, you're not going to see it on x-ray. And that's where it could become a bit of a headache of you get the x-ray, x-ray is clean as a whistle, and you're confident to walk away from this as a possible diagnosis. You're treating for a couple of weeks, patient's not getting better. You have to change, you get an x-ray again and then it's gotten worse. So x-ray's an option, just not the preferred option and it's relatively easy to miss. Now I want to be sensitive to if you work in a situation where there's a lot of insurance that you might have to get the x-ray first and then be able to get some other imaging modalities. So I understand having to play that, that reindeer game. So MRI itself is our, is our gold standard for a number of reasons. One, it allows us to see individual grading scale. So 0 to 5. And you're able to contrast on like T1, T2 weighted image, you'll generally see it down on 1, up on 2. There'll be ill-defined edema throughout. But what I like about MRI is you can see a lot more. You can see the bone edema. And then also there are very specific grading criteria. And that grading criteria, we'll show it, I'll show a table at the end. That grading criteria can be plugged in to return to run, return to recovery time. So it gives you a nice framework, especially when you're working to set expectations with your patient about how long is this going to take, or how are we going to manage this going forward. It gives you a nice framework and roadmap for them, especially if they're saying, well, I want to get back in 2 weeks and things like that. It makes things a lot easier for you from a communication standpoint. This table is from an initiative. This is the classification. Again, grade 1 through 4, 5 is complete fracture. And you can just see the different criteria for the level of edema and then what is seen with or without the fracture line. Diagnostic ultrasound, it's another potential imaging modality. Some states' scope of practice, it might not be readily available. What is nice about it is you can see stuff in real time. So if you can, if you can touch it with your hands, you can scan it. So if somebody's pointing to the, the middle of their shin or tibia, you can take a probe right there and scan it. And sometimes it's a lot cheaper than the MRI and you can see it in real time. Again, that just depends on what's available to you and what your license looks like. So getting back to the injuries themselves, we'll talk most common areas are tibia, tarsal navicular, metatarsals, femur neck and shaft, and then pelvis and sacrum. For this, I'll kind of focus on tibia and femur since they're Tibia is much more common, and then femur has the most moving pieces in my mind. So tibial stress fracture. So what, what's that going to look like? They're going to come in, pain focal to the anterior tibia, pain with more activity. I call it the pinky test personally, where if they can take the tip of their pinky and tap where it hurts, generally that's a really specific indicator that that's what's going on. Again, your other historical features, changes in trading, super active, things like that. There's 2 tests. It's not taught a whole lot in school. Milgram Research out of Israel has this study. They did 2 quick tests with a combined sensitivity of 100%. So if these 2 tests are negative, you can feel pretty confident about walking away from this diagnosis. The 2 things are, one, pain on palpation. Does it hurt if I poke that area? And then second hop test, having the patient perform a single leg hop test over that area. If they— that reproduces their pain and it's painful there, you have some confidence about this being a concerning emerging BSI. And then quickly, just, it's often a mimicker where you have medial tibial stress syndrome or shin splints present with or mimicking a BSI. Generally, a couple things to look that are different. One, look at the hop test, the pain on palpation.

Mm-hmm.

Second, if it's shin splints, the area of pain is a lot more broad throughout the shaft instead of one focal area. And that's due to the kind of periostitis with the tibia and like the muscular attachments there. So it's this more diffuse, non-focal pain instead of just that pinpoint area. And then looking into the other one of my favorites, the femur itself. Remember that we have those 2 types. So we have the shaft, the long portion of the bone that's on the low-risk category. And then we have the neck itself, the proximal end, that's in the high-risk category. So you'll often have a patient come in with this deep, really achy pain. Every patient I've seen with a femoral neck stress fracture, the phrase they've used is it's in there deep, or they'll be trying to show me where it is and they just keep on poking. They're like, I wish my hand could go deeper or I could poke more in because that's— it's beneath even where my hand is at there. And a couple of things you'll see, especially with the neck, is Really intense pain with the hop test. There's a test known as fulcrum test. You can see it on the picture there. That's where you'll take your hand and bring it underneath the patient's femoral shaft, take your other hand and press over that area. That allows you to kind of put a little, one, pressure onto the shaft itself, but two, you're jamming the head of the femur up into the, into the ilium. If there's irritation or inflammation, easy way to irritate it. And then other orthopedic tests might be helpful, Faber-Fabier. You're just seeing how easy is this to irritate. So the historical features, were there changes in activity, load, pain, things like that. And then if you're reproducing it with just moving their hip around and the patient's talking about it being in there deep, this needs to be on your radar relatively quickly. So the, the reason I, I'm so interested in the femoral stress fracture is one, it's the highest risk, but two, it has some different subtypes that aren't well touched on. So specifically there are, are 3 types for the femur. One, If there is a stretch— stress fracture on the superior, the upper side, versus on the bottom side, versus all the way through. So on the top side, that's referred to as a tensile stress fracture. Bottom side is referred to as compressive. And then you can have a complete, which is no bueno, that involves displacement. So if it's a tensile top side, that has— it's like a 40% increased chance of that Progressing, meaning to crack further, versus on the compressive, that bottom side is much less likely. So even knowing the subtype can be really helpful once you have the MRI about how you want to move forward with this and how you want to manage this. And again, harping on the, the role of the MRI, you can see from this table here, it's American Journal of Sports Medicine. This is for the neck itself, talking about the grading scale, and then they followed the number of athletes and saw how long it took them to return to run. So for a grade 1, it was about 7. For a grade 2, about 14 weeks. 3, about 15. And then 4, about 17, 18. So look at the huge difference. So 7 versus 14. Once you— a grade 1 to a grade 2, you essentially double the timeline. And grade 1 is about 2-ish months, give or take. Grade 2, we're talking 3, 4 months or more and going beyond that. So the sooner you can catch these, the better things are going to be for everybody involved. If you can catch an injury at a grade 1, manage it, you have a better shot to get them either back to their events or to their season than a grade 2, 14 weeks of healing time. Like, a lot of sport is going to be over before then, and that's frustrating for everybody involved. So. As soon as you can identify these, that's, that's optimal. And again, with the study about the epidemiology, a lot of these result in 3 weeks of time lost, the medical disqualification, or the end of season. Again, the soonest you can catch these, that's going to help everybody.

That's it for today's episode. Be sure to tune in for part 2, where we discuss the phases of returning to activity after a bone stress injury, as well as talk about some helpful tips for maintaining fitness and strength during the recovery period. Dr. Kemp will also share a few fascinating case studies and offer advice on how to have effective conversations with parents, coaches, and healthcare providers. You won't wanna miss it. Episode 67 drops in 2 weeks. Be sure to check out our show notes for special offers from our sponsors and a link to our Factor 60-second survey for the week. You'll also find a link to view the full recorded replay of this webinar if you're more of a visual learner. You can subscribe to the Factor podcast on Apple, Spotify, iHeartRadio, or the podcast app that works best for you. Be sure to follow the show and give us a 5-star rating. Every little bit helps. We'll see you next time. Hey guys, if you like what you heard today, I encourage you to visit our website at factor-store.com. That's spelled F-A-K-T-R-store.com to find out more information about all that we have to offer. We have a variety of online offerings as well as our hands-on Factor Rehab System course Scheduled in cities around the globe. Be sure to also check out our event calendar and bookmark any of these upcoming live webinar dates coming up in the near future so you can join us live. And of course, the biggest compliment we can receive is for you to help us spread the word to your friends, colleagues, and classmates. You'll find all the important links as well as info about our sponsors in the show notes, so be sure to check those out.