Paul and Howard talk about rotator cuffs, those four muscles around your shoulder that often go awry and sometimes really hurt.
- What are rotator cuffs anyway?
- Tossing, tools, and trees: the evolutionary history of shoulders
- What happens if part of your rotator cuff goes, you know, missing?
- Pretty much everyone over 45 has rotator cuff problems. Most don’t notice.
- The future of fixing — and/or not fixing — rotator cuff problems
- Shoulder MRI Findings in People with NO Shoulder Pain: Are Some Tears “Normal”
- Calcific Tendonitis — What is it?
- Fossil hominin shoulders support an African ape-like last common ancestor of humans and chimpanzees
“Crossing the Chasm” by Kevin MacLeod (incompetech.com) licensed under Creative Commons: By Attribution 3.0
Disclaimers apply (at the end of the episode).
About The Show
Paul Kedrosky is a frequently injured athlete and a venture capitalist. Howard Luks is a top sports orthopedic surgeon. Smart, candid, and experienced analysis, ideas and tips about health, fitness, and longevity from two athletes and sports orthopedic surgeon—and guests.
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Paul: [00:00:00] You can’t build a whole house out of fireplaces and you can’t do a whole rotator cuff repair out of anchors.
Howard: [00:00:07] It can be such intense pain. They are one of the most uncomfortable people in the office.
Paul: [00:00:13] As you know, I have a longstanding grievance about rotator cuffs, but I’ve come around, unlike my views on other joints. For a while I had decided that rotator cuffs were a fairly crap design, but the shoulders a pretty interesting place. With your coaching, I have flipped on the shoulder and specifically the rotator cuff. So
Howard: [00:00:30] it’s good. That it’s good. That you’re still teachable at this age. I’m not sure I can say the same.
Paul: [00:00:36] Now, and then there are flashes.
Rotator cuffs got really good marketing, there’s all kinds of other injuries in the body that are. probably at least or if not more common, but everyone knows about rotator cuffs. The numbers are pretty striking, something like a 22% prevalence among adults; something like 460,000 surgeries a year. Those are just huge numbers.
Howard: [00:00:57] It really is incredible the number of people who have shoulder pain, I’m stopped on the street, by people who know me more for shoulder pain than for knee pain. And you’re right. If someone has a painful shoulder, regardless of their age, they’re going to say I have a rotator cuff or perhaps rotator cup, problem.
Paul: [00:01:20] Those darn rotator cups. the other thing that’s pretty striking and we’ll come back to this , but it’s worth noting. And that comes from that original study. But this is also just widely known that most people over age 40, would you say more than half over 45, if you ran them through an MRI and had a look, you’d find something resembling some kind of, maybe not, a full thickness tear, but it’s going to be something going on in one of the muscles around the rotator cuff.
Howard: [00:01:48] Without a doubt. I refer to this as rotator cuff disease because it really is a disease. The rotator cuff just starts to degenerate. And it starts with a little fraying. it starts with some internal changes and that fraying can progress, to become a full thickness tear. over time.
Paul: [00:02:07] What’s going on here in terms of the structure, the rotator cuff. There’s like we’ve got a couple of joints involved. We’ve got four major muscles on two different ligaments, but the gist is that there’s four main muscles typically involved in making sure your arm doesn’t fall off. Those are the ones that tend to be most actively involved in what we call a rotator cuff injury.
Howard: [00:02:29] Absolutely. So the one that’s most commonly held responsible for problems is the superspinatus. It’s not really involved in the physics of how the shoulder functions in terms of force couples, and it’s the first to degenerate, but the infraspinatus in the back is more important, and second most commonly injured. Interestingly, the teris minor, which is way down in the back is almost never injured. and the subscapularis, which is really the boss of the rotator cuff up front, it’s the biggest and most powerful, and it takes a big injury to injure that one.
Paul: [00:03:10] So all of these collectively allow us to do a bunch of really complicated things. This is a ball and socket joint, and so it’s got not really, truly 360 degree rotation and three dimensions, but at least in a plane, it’s got more than 360 degrees of movement, which is possible because you have this big ball sitting in a shallow socket, with a bunch of muscles that allow it to go pretty much any direction it wants to go.
Howard: [00:03:35] it’s a vertically oriented joint and to think about the disparity in size, just think of a golf ball on a golf tee. And the socket, as you noted, the glenoid, is relatively flat. So we have the labrum to widen the socket and deepen it. And what many people don’t understand, the shoulder has negative pressure, so when we stick a scope in it, one way, you know, that you got in, you hear the sort of ssst because you slid into it and you equilibrated the air pressure.
N ow the rotator cuff holds the humerus, the humeral head down into the socket. It doesn’t pull it up. And if that rotator cuff is not functioning well, then the head of the humerus where the rotator cuff attaches can migrate upwards or proximally, can do so statically, if there’s a large tear where it migrates up and we develop a big problem because of that or can do it dynamically.
So if you decided that you want to start pitching and you go outside and throw a hundred balls and your shoulder starts hurting, you probably exhausted you rotator cuff it migrated up, impinged
Paul: [00:04:48] But also it’s prone to dislocation, or I guess a partial dislocation. Because that’s part and parcel of having such a shallow socket.
Howard: [00:04:55] Yes. There’s a labrum that encircles the glenoid, and it serves to deepen the socket and widen the surface area. It also serves as the attachment point for the ligaments that connect the ball to the socket and prevent our shoulder from dislocating. The shoulder just wants to rotate, it doesn’t want to translate, so it doesn’t want to move forward, or backward. But if you start moving excessively or if you are struck or if you fall, then the shoulder can translate or move forward or backwards, thus pushing the ball off the front or the back of the socket. And when you do that, it’s usually accompanied by a labral tear. and that labral tear will,enable the shoulder to continue dislocating.
Paul: [00:05:43] So Two questions. So one, you were talking about the negative pressure in the socket, and this is just a completely stupid engineering question probably, but I’m curious if someone has a labral tear, and does that mean if it’s severe enough that negative pressure no longer exists, therefore, that’s one of the reasons why you’re more prone to dislocations.
Howard: [00:06:03] so I don’t think so. We still get that same sound. When we put a scope into a shoulder with a labral tear.
Paul: [00:06:12] And so that’s a completely, as I said, for lapsed engineer question, and the second one is, if I forgotten what superspinatus is most is the most prone to being injured. Is that right? if if I didn’t have one, what couldn’t I do.
Howard: [00:06:28] that’s a great question. you would probably lead a very normal and active life without the superspinatus, To understand that, you need to understand the force couple. So we have one in the axial plane. So it’s like putting you on a meat slicer and one in the frontal plane or the coronal plane. And, those two forces work against each other so that the shoulder can rotate in, out, up and down. And the superspinatus doesn’t really participate in those force couples, so it is far less important than most believe it to be. And it’s also a lot smaller, dissecting out the attachment of the rotator cuff is challenging cause they all the tendons really coalesce when they attach to the humerus. So it’s hard to define which is which, but they’ve gotten a lot better at it in some anatomical studies. And the superspinatus really has a very small footprint.
Paul: [00:07:27] You’ve alluded to this already. why is it so prone to injury? Now, you’ve suggested that injury might be the wrong word, that is a, it’s more like a disease; this is something that seems to be progressive and an awful lot of us make it bipedal, apes, we can’t talk to our ape cousins and find out if they have the same problems. It’s a little bit harder to know, but nevertheless, it seems more like a disease progression in many cases than like an acute process, even though there are obviously acute processes in many people. Why do you think that is? It seems to be a unique area of the body in terms of this early pathology, this degradation, you don’t see it in the same way in my in other joints in the body that they have by age 45, you’re having this degradation on imaging and so on.
Howard: [00:08:10] So the number one cause of tendon related pain degeneration and tears is tendinopathy or tendinosis. So we’ll see that in quad tears or patella, tendon tears, we’ll see it in Achilles tears as well. But the superspinatus is particularly vulnerable. In many of us, again, back to physics, we have what’s called a cable dominant shoulder or cuff tear pattern where there’s this cable that runs, transversely from front to back, across the insertion and it takes the force away from the superspinatus. It’s like a suspension bridge model. And because there’s no tension at the footprint attachment of the superspinatus, then the body isn’t going to grow that tendon or grow that footprint. So the tendon becomes weak and the crescent, which is that thin remaining segment, just dissolves with time and goes away.
we also think that there’s an issue with vascularity. There’s less blood flow to this region of the superspinatus. And it does appear that our metabolism matters. They’re finding that there’s cholesterol deposition or uric acid deposition and other changes in the tendon architecture at a microscopic level in people with lipid disorders and other metabolic disorders.
Paul: [00:09:44] Reading about the evolution of the shoulder is fascinating because we can only speculate based on what we see in our own shoulders and what we see on our ape friends’ shoulders and what we see in terms of skeletal remains of what we think were likely in the ancestors, in the family tree. And one of the hypotheses in that literature with respect to why it’s so prone to injuries is because it’s not quite a hack, but it’s a bunch of compromises that our more tree dwelling ape friends had evolved in a particular way that it was most advantaged when they were hanging by their arms and swinging through trees. And as we slowly moved from a tree existence to a more terrestrial existence, we began evolving this different. orientation of the scapula and a different orientation of the shoulders and a different set of musculature, that allows to use tools and, other things on the ground. And even throwing evolved out of that and made us pretty wicked, dangerous throwing rocks at things. Point being though that we’re good at a bunch of things. We’re pretty good at throwing. We’re pretty good at lifting. We’re good with.Tools. But we’re not particularly great at anything, unlike the apes that we evolved from. So the argument in that literature is one of the reasons why it’s so prone is because unlike so many joints in the body, it has to be good at so many things and not necessarily great at any one of them, because there’s no evolutionary advantage to just being great at one of them. We can’t really test it that well, but it’s really intriguing as a possible explanation for why the shoulder is so prone: it’s because it’s this multi-tool of joints.
Howard: [00:11:15] You realize just how complex it is when you start to mess with it and fix things.
Paul: [00:11:23] Just, Once you’re inside a body things blur into each other in many ways, right? It’s not always obvious where one thing stops and another thing ends. Is the shoulder also complicated to work on because of that problem, that everything is where you’re working in a tight space with a lot of different, pieces of musculature and ligaments that are all in some sense, the boundaries begin to blur into each other.
Howard: [00:11:46] it’s absolutely true. The shoulder has a lot of large major structures such as for rotator cuff muscles, etc. It has a lot of small ligaments, coracohumeral ligament, coracoacromial ligament, et cetera. And there are a lot of nuances in there about the anatomy that you don’t truly appreciate until you’re later on in your career that understanding the anatomy and where you are and what you’re doing and what you’re releasing, enables you to repair things you may not have been able to repair when you first started, enables you to determine how to repair things. Our scope is a two dimensional picture, yet our brain needs to create a three dimensional image of the tear pattern, in order to know how to best to fix it. And I can tell you after trainin, a hundred residents that it’s not easy to determine what that tear pattern is.
Paul: [00:12:46] Yeah. All of a sudden you get inside a shoulder and all sorts of things start to blur into each other. It becomes multi causal and all sorts of things.
So what are the most common cuff injuries that you see out there? You talked about tendinopathy, we’ve alluded to partial and full thickness tears. What other sorts of pathologies and problems do you see in the rotator cuff or in that general area?
Howard: [00:13:07] calcific tendinitis is really common. we’re starting to learn more about etiology and why it exists. But we’re still not entirely sure. It might be due to microtrauma or prior injuries. It might be due to a low oxygen environment, but you develop this deposit of a toothpaste consistency calcium into your rotator cuff and in the process of trying to dissolve it the body will cause you such great discomfort that you will not be able to sleep and you come crawling into an orthopedist office. And these people can be picked out of a waiting room quite easily.
And we wait. It really is.
It can be such intense pain. They are one of the most uncomfortable people in the office. Now we have bursitis, right? Everyone’s heard of bursitis and they think it only occurs in the hip, but only we have a thousand bursa in our body. And the rotator cuff has a bursa as well. The body puts a bursa, which is just a fluid filled sac, between any structure and a bony prominence to eliminate the friction. And the way we know , a lot of people with shoulder pain can’t sleep at night. So that night pain tends to be a bursitis.
Paul: [00:14:27] Why is that by the way?
Howard: [00:14:28] That’s a great question. We’re known and faulted for thinking messy, mechanistically, and torn must fix broke, must fix, et cetera. So a lot of people who would say that it’s the rotator cuff that’s irritating the bursa. I honestly don’t know what incites a bursitis, because I’ve seen tremendously torn rotator cuffs in people who have full function and don’t want you to touch them. And I’ve seen people with minimal cuff changes have a vicious bursitis.
We don’t always understand what sets off a bursitis, but if you’re not sleeping well and you’re tossing and turning it’s usually because you have bursitis, it’s not because your rotator cuff is torn. However, people who are trying to reach up to the top of the cabinet, trying to work in a tree and they’re reaching over their head and they have pain at the extremes and also have pain bringing the arm back down, those people tend to have a painful rotator cuff. So that can be a tendonitis from overuse. That’s changed that starts in the tendon that will lead to partial tearing or fraying of the rotator cuff, more thicker tearing, and then eventually a full tear where the tendon is no longer attached to the bone.
Paul: [00:15:48] And at the risk of triggering Howard here, I know there’s one that’s a hot button for you. One of your favorites: so, bone spurs. Let’s talk about that nasty business of bone spurs in the shoulder as a cause of rotator cuff problems.
Howard: [00:16:06] The concept that the bone spurs, the cause of a rotator cuff tear started decades ago, but this was a theory that was never peer reviewed and it just grabbed hold and took off. And all of a sudden everyone with shoulder pain was getting this bone spur removed through open surgery initially, and then through arthoscopic surgery. But the studies over time have shown that if you repair a rotator cuff and don’t touch the bone spur versus repair and ablate the bone spur it doesn’t matter. Studies show that if you take the bone spur out, someone’s pain will come back a few years later. The bone spurs not thought to be a relevant cause of rotator cuff pathology. Still to this day, you can walk into an orthopedist office and they say, look, you have a bone spur and that’s the cause of your shoulder pain.
Look, we have spurs throughout a body. We develop traction spurs attraction. Spur is simple. If you have a ligament attaching to the bone, that ligament is under a lot of tension it’s pulling on that bone constantly. That causes the bone to react a lot of times and causes these spurs to form at the ligament attachment in the ligament attachment. If you put your finger inside the subacromial space, where the rotator cuff resides and swipe it back and forth, you don’t feel a sharp spur. You just feel this nice smooth curve. It’s not as if there’s something projecting downward into the rotator cuff and abrading it away, but it’s an easy concept to teach. It’s an easy concept as a physician to tell your patient. And it’s easy to understand from the patient
Paul: [00:18:00] I would presume that having identified it and decided it’s the cause it’s also something that from a surgical standpoint, I can just go right in and whack it and feel like I did something.
Howard: [00:18:10] Without a doubt. And for decades, we did that open, before the advent of the arthroscope. And then that became the most commonly performed shoulder procedure. I’m glad to say that it’s dwindling in terms of incidence now.
Paul: [00:18:27] If you did nothing else and someone had something wrong, is it your sense that having removed a bone spur that patients then reported improvement, which would imply that it was probably largely a placebo effect?
Howard: [00:18:38] Oh, there’s no doubt.. And when you go in to take out the bone spur, that’s not the only thing you’re taking out, the bursa’s in your way. So you’re taking out that versus so if someone had a bursitis, that’s going to be removed. If there was a partial tear or some fraying of a rotator cuff, you’re going to take that away as well.
But if you talk to shoulder surgeons throughout the globe, they will tell you that they do not perform isolated bones spur removals, for the treatment of rotator cuff pain and shoulders anymore.
Paul: [00:19:13] So let’s talk about treatment in general. my My shoulder hurts. It’s been hurting for a week. There was no obvious cause .What’s the first natural next step?
I always say your options are doing nothing, which is not really nothing but nothing or something. So then nothing option is as, ibuprofen, rest, see if it goes away. My rule in general is that things that don’t kill you, you have a tendency to go away, so it hasn’t killed you yet give it time.
And then on the other side, there’s do something. Go see a doctor, do some physiotherapy, do some strengthening. There’s a whole host of things. So let’s walk down a decision tree: someone’s got shoulder pain for a week. They haven’t done anything yet. You’ve run into them on the street.
Howard: [00:20:00] So it, it depends on the severity of the pain. if you’re noticing an ache as you lift a little discomfort, when you roll over at night, some difficulty stretching, you’re going to wait this out. And I know that these tendinopathies can take quite a while to go away and resolve. And if it’s not really dramatically affecting your quality of life, often waiting is the best thing. If it persists, if you’re going on a month, five weeks and you’re concerned by all means you’re going to come in and probably end up in a physical therapist office.
Now I alluded to the fact of, calcific tendonitis as a tremendous source of pain. If you’re off the wall and can’t sleep, you sh come into the office because we have a relatively simple fix for that that’s not surgical. That would be an ultrasound guided injection or lavage where we can wash the calcium out. It’s very effective for people who are that miserable.
now this into account, when we’re talking about this algorithm, it, that the onset was a traumatic. you and I discuss this all the time. We want to avoid being a statistic. meaning if we rush to our primary care doctor’s office, we’re probably gonna get an MRI. If we’re 65 years old, that image might show a rotator cuff tear. If you get referred to the wrong shoulder surgeon that might put you in an operating room, all for something that the didn’t need an operation andwhose pain was going to go away in a few weeks to a few more
Paul: [00:21:49] And for a tear that might’ve been for a decade or more or longer.
Howard: [00:21:52] Correct. they did a great study where they took people who quote unquote, did not respond to conservative treatment. So injections, therapy, medications, et cetera, these people were indicated for a rotator cuff repair. They imaged the non painful shoulder prior to surgery, and they found that a significant portion of people had not only a tear, but the same size and location tear as the shoulder that they were going to operate on.
Paul: [00:22:27] Yeah, shoulders are just followers. They just can’t bear having one shoulder get all the attention. It’s curse you. I have to have the same problem I want to be looked at. Yeah. Yeah, which should be striking to people, obviously that they’ve. these within reason, these shoulders have the same mileage and the same number of years. THey’re like car tires. It’s not particularly surprising: they have the same amount of wear, and often in the same places.
Howard: [00:22:50] Exactly. And we see the same thing in knees with meniscus tears, in many other areas.
Paul: [00:22:55] Uh,
Howard: [00:22:56] it just pays to be careful.
Paul: [00:22:58] So, it’s not calcification the pain hasn’t gone away, didn’t respond to physiotherapy. What’s next.
Howard: [00:23:07] We can try injection,. but a caveat here. Injections, can have a dramatic impact on rotator cuff healing, surgical healing. and infection risk. Some papers have said that a single corticosteroid injection around the rotator cuff will increase the risk of recurrence and needing revision surgery and increase the risk of the tear not healing for up to a year after the injection. So if you haven’t responded to physical therapy, you tried some Advil, Aleve, some Tylenol you’re six or eight weeks into this. It’s probably a better idea to image or MRI that shoulder before you consider an injection because if you have a decent size tear and there’s a chance that you’re going down that path, and you had an injection that later is found to be ineffective, now you’re stuck.
Paul: [00:24:10] Right now. Yeah, you got nowhere to go. So we do the MRI. It’s a, the full thickness tears, the question I suppose, answers themselves, but does that make life any easier with respect to falling down this diagnostic tree in terms of future actions?
Howard: [00:24:24] not necessarily, I can see people in the office with mild arthritic change on a knee x-ray yet there have an incredible amount of pain due to inflammation and synovitis .Yet the next person has horrible arthritis, takes a tylenol can walk, 18 holes on a golf course. So you can’t always predict the severity of someone’s pain based upon an image finding. And the same goes for the rotator cuff. we may have someone who has severe shoulder pain and they haven’t responded to anything and we get an MRI and it shows a partial rotator cuff tear. That doesn’t mean that’s the cause of the pain. And then a lot of those people will end up with an operation, which basically just cleans that up or shaves it a little. I don’t know what that does. but some of those people do get better. Now, yes, we remove the bursa. We’ve done other things. You never just go in and shave this tear, which makes studying this challenging. But some people don’t have a choice. if you’re young active and you’re not sleeping well, you can’t do anything with the shoulder, and you’ve tried everything, you’re going to reach for a solution. And a lot of times these arthroscopies are successful.
Paul: [00:25:44] What are some contraindications here as reasons why you might still do nothing
Howard: [00:25:49] so certainly the older we get, the less likely it is that a rotator cuff is going to heal. The degree of degeneration is just going to increase in your ability to heal is going to decrease. when we repair a rotator cuff, we put these little anchors into your bone. and if you have osteoporosis and you’re 80 years old, that anchor might not stay in your bone. So we won’t be able to repair it anyway. but someone’s medical status has to be taken into account, at as well. and very important, occasionally you’re going to have someone who slipped and fell or you’ve fallen down the stairs; you reached for the railing and you felt something rip in your shoulder. The vast majority of rotators cuff tears that we see in the office are chronic or attritional, degenerative, or atraumatic, all the same. Versus those of us who have fallen and injured ourselves. And you have an account acute, traumatic rotator cuff tear. it’s pretty well accepted in the shoulder world, that if you have an acute traumatic rotator cuff tear, we’re gonna fix that. As opposed to the same size tear in someone who’s had pain for four years and a tear looks like it’s many years old. We may not choose to fix that one.
Paul: [00:27:19] How would you characterize the success rate on, uh, on whatever the ideal patient might be? Just without getting into edge cases. And in general, how successful is if it had to happen, we’ve gone to all the way down this tree, and this is now what you’ve been forced to have to do, whether it’s traumatic or not.
Howard: [00:27:39] if you’re managing people with, traumatic tears that are fixed rapidly, and fixed well, the success rate is very high. if you’re dealing with small tears or what we would term a moderate tear, and it’s chronic or attritional, and you didn’t respond to other treatments and it’s a easily repairable tear, you also have a very good good chance of success. You have a high risk of it recurring in the next five to 10 years, but you’re going to feel a lot better. If you have a large tear, these chronic attritional tears that have been there for a long time, those are really tricky. And the failure rate is high. We’re devising other procedures for those, that are still being tested.
Paul: [00:28:30] What’s the future look like to you? Or maybe put a different way, what sorts of things are we doing now that will look, I don’t know, barbaric to people a decade or a couple of decades from now. what’s the future look like in that sense? What are we going to abandon and what are we going to do?
Howard: [00:28:44] Yeah, we’re going to abandon our search for stronger anchors and stronger sutures and different devices to pass sutures through tendons. we have developed, tiny sutures that I can let you hang from a bridge from, and I know it’s not gonna rip .Yet, we’re putting that through … imagine sewing, a hole through a pair of jeans that you’ve had for 25 years. I don’t care how strong the thread is, that hole is not going to stay closed. It’s a tissue problem. So we need to better on this, the biology of tendon failure, of tendon degeneration, and of tendon healing. Why are these tears occurring? Why is this degeneration occurring? What can we inject into your tendon? What medication can we give you, to change the biological and an environment so early degeneration doesn’t turn into a tear. And then when we do operate, on you, what can we do to encourage healing to take place sooner before the sutures cut through the tissue and the repair fails.
Paul: [00:29:57] Is there anything else in terms of, I don’t know, biologics and injectables or anything else to, in terms of promoting healing, do you see a role in there for some of those kinds of products.
Howard: [00:30:07] So right now, 2020, those don’t exist. a lot of people are getting PRP, injecting STEM cells and they’re wasting their money. So do I envision, that something will come along, and that we’ll have a biological alternative to offer to people? Yes. STEM cells are interesting.
if you take stem cells out of your bone marrow and inject them into the shoulder or the knee joint, unfortunately they just sit there. They don’t know what to do because the chemicals, the chemical signals don’t exist to tell them. So we have to find what chemicals do we need to put into this milieu to tell these cells what to do?
Paul: [00:30:54] As you were talking about these incredibly strong anchors and, sutures, I was reminded of a friend of mine saying the other day he was looking at pictures from these horrible California wildfires and noticing that on the houses or at least the remains of the houses that he saw in the pictures there’s always the fireplace has left behind. And, which is interesting and sad at the same time. And so his naive suggestion was, why don’t we just build the whole house out of fireplaces, right? Which is the same problem with — which obviously doesn’t work — but it’s the same problem we’ve got ourselves into when you start thinking about it, doesn’t matter how many super strong sutures and anchors you put in, there’s still fundamentally a problem. You can’t build a whole house out of fireplaces and you can’t do a whole rotator cuff repair out of anchors. Right?
Howard: [00:31:38] It’s so very true, but it’s taken us 30 years to learn that.