Transcription:
Use of Muscle Atrophy and Fatty Infiltration in Surgical Decision Making for Rotator Cuff Tears

Melanie Cole (Host):  Welcome to Better Edge, a Northwestern Medicine podcast for physicians. I’m Melanie Cole and today, we’re discussing rotator cuff muscle atrophy and fatty infiltration as it applies to surgical indications. Joining me is Dr. Lucas Buchler. He’s an Assistant Professor of Orthopedic Surgery at Northwestern Medicine. Dr. Buchler, thank you so much for joining us. Please tell us how you came to Northwestern Medicine. You’ve had some interesting and frankly pretty cool jobs before this. Tell us about that.

Lucas Buchler, MD (Guest):  So, really it is a bit of a homecoming for me. So, I grew up just outside of Chicago in Northwest Indiana. Did my undergraduate at De Paul University and then my medical school at Indiana University. And then I did my residency here at Northwestern downtown. So, I was at Northwestern for five years. I left for a year and did a sports medicine fellowship in Denver, Colorado and worked as an Assistant Team Physician for the Denver Broncos and Colorado Rockies and had a really great experience there. And then over the course of that year was in several conversations with our Chairman Dr. Peabody and our Sports Medicine Team here and decided to bring things full circle and come back to Northwestern. So, now I’m back as you mentioned as an Assistant Professor here. I have some involvement with our clinical research infrastructure as well as our resident education program. And I serve as an Assistant Team Physician for the Chicago Cubs and a Network Team Physician for the US Ski and Snowboard Team.

Host:  How cool is that. Well thank you for telling us about that. So, as a general overview, talk us through the pathology of rotator cuffs and why injuries are so common in athletes.

Dr. Buchler:  So, rotator cuff injuries are incredibly common, and they largely fall into a few buckets and so, in younger active patients, they tend to be more traumatic or what we would call attritional injuries. So, in our overhead throwers, there’s some wear and tear on the rotator cuff with time and parts of the rotator cuff can become thin and injured. It’s rare however, for a young athlete to require surgical repair of those injuries. They can be painful. They can be problematic. But most of the time, we are able to treat them nonsurgically.

The other group of rotator cuff injuries happen with a little bit more age and so, again two varieties of those. There are traumatic or acute injuries where someone has an acute fall or some other type of injury where the rotator cuff tears or there’s chronic injuries where the rotator cuff thins over time and as it becomes a little bit thinner, a little bit thinner; eventually portions of it may wear all the way through. I think it’s important to note the rotator cuff, though we talk about it as if it’s this separate musculoskeletal structure, it’s really a tendon. It’s a group of tendons from some muscles on the shoulder blade that help keep the ball of the shoulder, ball and socket centered and injuries to it can cause lots of pain with overhead activities.

Host:  So, tell us about the evaluation process. What does that look like when caring for rotator cuff injuries Doctor and why is it important to the patient? Tell us a little bit about the evaluation and review your general treatment algorithm because it is tough to diagnose these types of injuries because the shoulder as you said is so complicated. Please review that for us.

Dr. Buchler:  So, rotator cuff pathology in general, is the most common reason we see folks with shoulder pain. So, we see a lot of folks every day in our office who have rotator cuff problems. What makes it difficult is that for every one rotator cuff problem that causes pain and for every patient that shows up in our office; there’s probably eight or nine others who have the same rotator cuff problems, but they are not symptomatic and not causing pain. So, we spend a lot of time and energy and effort on ensuring that the rotator cuff problem is indeed the cause of the pain because we know that there’s a lot of asymptomatic rotator cuff pathology, a lot of folks walking out with even full rotator cuff tears who have no symptoms at all.

So, when we see folks in the office, first and foremost, is we gather a history from them and discuss and ensure that this history of their symptoms and their functional limitations line up with the rotator cuff pathology. And then we examine the shoulder and try to evaluate and determine what is the primary cause of the pain. There’s a lot of overlap from other structures, muscular dysfunction around the shoulder otherwise long head of the biceps problem, cervical spine problems, so, we spend a lot of time talking about that. Once we’ve identified that it is the rotator cuff that’s causing pain or problems; it’s important that we differentiate if the problem with the rotator cuff happened acutely or more chronically.

Most rotator cuff tears are chronic in that they are insidious in onset, they develop over time and without one injury or traumatic event. Those we treat most of the time with a course of nonsurgical treatment with some exceptions for younger patient ages and a few different things we would consider. Most of them, however, are chronic in nature and we’re going to treat those with a prolonged course of nonsurgical management with physical therapy, oral anti-inflammatory medications and sometimes steroid injections and the vast majority of those will get better on their own. So, it’s really a very small subset of the overall rotator cuff pathology that we end up operating on.

From a specific algorithm, when I see a patient, there’s two things I think of first. One, I consider their age. So, patients under the age of between 55 and 60 depending on what you read with full thickness rotator cuff tears; we are more apt to consider early surgical intervention because we are concerned about this process of fatty infiltration and atrophy of the muscles. For patients 65 and older, we know that asymptomatic rotator cuff tears are incredibly common and so we’re more apt to treat those with a course of nonsurgical management.

And then second distinction is acute versus nonacute or acute versus chronic. So, acute traumatic rotator cuff tears, the outcomes from nonsurgical treatment or delayed surgical treatment are not nearly as good as they are for acute surgical repairs. So, in the setting of a traumatic rotator cuff injury, we are more apt to recommend early surgical intervention. And then the final distinction would be those partial thickness tears. The tears that don’t go all the way through the tendon but just include some of the fibers. Those we are going to treat nonsurgically however we can. Only we would treat those surgically if they were to fail everything we have from a nonsurgical standpoint.

Host:  What a fascinating topic we’re discussing today Doctor, so speak a little bit about fatty infiltration and muscular atrophy and the effect that that has on your surgical decision making process and as far as atrophy in the supraspinatus and infraspinatus muscles; tell us a little bit how this affects your decision.

Dr. Buchler:  So, it’s a really interesting topic and it’s one that I came to interest of when I was a resident doing some research with some of our shoulder surgeons as well as some of our PhD researchers in our physical therapy school. And what we talked about is that we know that rotator cuff repair surgery is a great surgery. Most patients do very, very well. But there is still a small subset that don’t do quite as well and there’s some suggestion that maybe it’s those patients who the muscle is not in very good condition anymore at the time of the repair. So, if the muscle is atrophied or if it’s been replaced by fat, maybe the outcomes aren’t quite as good in those patients and we thought what if we sought a better way to understand that process a better way to evaluate that.

Traditionally, we’ve looked at that on a single cross sectional slice on an MRI and classified it based on how much fat and muscle we see but what we found with our research is that the changes in the muscle can be much more three dimensional and Amy Sites who is a physical therapist that we work with and has lead the way on a lot of this research, her team came up with an algorithm and a way that we can volumetrically from a three dimensional MRI assess how much fat content there is in each muscle and specifically and compare that to a normal muscle around the shoulder, traditionally at least the triceps or the tares major. We think that the tares major is probably the best target but that’s a different topic for a different day.

So, from a clinical standpoint, it’s not feasible for us to do a complete reconstruction and three dimensional analysis on every single patient but it’s taught me to look more detailed at the rotator cuff muscles for every patient that I evaluate. So, I look through the entire MRI. I look through all of the muscles and try to get a better sense for the quality of the muscle and we know that the fatty infiltration and atrophy process probably takes close to a year to occur. And so, if a patient has had a new onset of symptoms, for example, or had a recent injury, and we look at their MRI and they have very significant degeneration, fatty atrophy of their rotator cuff muscles, we say well even though the symptoms were acute in onset, this is likely more of a chronic problem and we’re more likely to try to treat that nonsurgically rather than grouping it as an acute or traumatic rotator cuff tear.

Host:  That is really interesting. So, tell us a little bit about the variolas and your outcome measures. Tell us what have you been seeing from what you’re doing.

Dr. Buchler:  So, thus far, we have not had direct clinical application of the research sites. So, we would love to get to a point where we could streamline the process of segmenting and reconstructing and doing complete muscle analysis on every single rotator cuff problem that we see but we haven’t seen that thus far. What we have changed is we’ve changed the way we do MRIs. Traditionally, the MRI for a rotator cuff would stop just medial of the glenoid so we would see part of the rotator cuff muscles, but you wouldn’t see all of them. We’ve changed to where we have our MRI scans go all the way through to the medial border of the scapula so that we see the entirety of the rotator cuff musculature. And second, I think that if you look not just at our practice but globally, as we’ve tightened and better aligned our indications for surgical treatment of rotator cuff problems, our outcomes have improved. And we see that in our patients. We track the patient reported outcomes. And the patients do very well from this surgery. But I think what’s happened is we’ve become a bit more selective about ensuring that we’re trying to look on the frontend for who is that patient that maybe would not do as well with the surgery and maybe we should consider a different route or a different treatment for them.

Host:  So, Doctor, before we wrap up, what else would you like orthopedic surgeons to know and other providers to know about what you’re doing there as far as fatty infiltration and muscle atrophy and rotator cuff injuries. Kind of summarize it for us with your best advice.

Dr. Buchler:  So, I think a few things. I think one is to look critically at the muscle itself and to look for the fat content within the muscle and the quality of the muscle compared to the surrounding muscles visible on the MRI. I think that that’s something that’s changed as I learned more about this. I don’t just look at the tendon itself to see if it’s torn away from the bone. Once I see that the tendon has torn away from the bone, I look directly back to the muscles around the shoulder blade to ensure that the muscles are still in good condition. The last thing I want to do is put a patient through a rotator cuff repair and a six month recovery for them to be a little bit better or not much different. We want this to be a significant improvement for them. And so that would be the first thing.

And then the second thing would be to just be cognizant of this process and I think to follow the coming research. I think we don’t know exactly where this field is going. There’s a lot of exciting research being done on the basic science side because as of right now, our understanding is that fatty atrophy or fatty infiltration is an irreversible process and there’s some exciting research being done by a variety of scientists through the country about is there a way that we can intervene and reverse that process whether mechanically or with pharmacologic treatment so that even if a muscle has had some fatty infiltration or some atrophy, is there a way we can reverse that process and find a way to have better outcomes for those patients.

Host:  Great information. Absolutely fascinating Dr. Buchler. Thank you so much for coming on with us and telling us about that and sharing your expertise. And that concludes this episode of Better Edge, a Northwestern Medicine podcast for physicians. To refer you patient please visit our website at www.nm.org to get connected with one of our providers. Please also remember to subscribe, rate and review this podcast and all the other Northwestern Medicine podcasts. I’m Melanie Cole.