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Hi everybody. My name's Jo Gibson. I'm a consultant, shoulder physiotherapist in Liverpool in the UK and I previously worked as a shoulder specialist in the Liverpool Upper Limb unit. We have been running our free webinar, and we've had some fantastic feedback.

We ran out of time to answer everybody's questions. So I promised that I was gonna answer some of those residual questions and hopefully fill in some of the gaps.

So tonight's questions what is cuff arthropathy? Why is subscap tears so much of a problem and what sort of injuries commonly cause subscap injuries?

Rotator cuff arthropathy essentially describes a pattern of glenohumeral joint degenerative changes, which essentially follows chronic rotator cuff tears. Now you look at this characteristic features, you get superior migration of the humeral head, erosion of the greater tuberosity, and so the humeral head ends up looking a bit like the femur, so it's called femoralisation.

You also get this erosion and contouring of the coraco acromial arch, and that's called acetabularisation cause it looks like the acetabulum. And essentially that's to create a socket for that kind of change of the humeral head and. Ultimately, they can then develop glenohumeral joint arthritis. But clearly preceding that, you've got joint space narrowing.

Now, it's very different from just having a massive cuff tear. It's a sequence of events. Now, commonly it's stipulated as being a consequence of massive rotator cuff tears, particularly those that have got anterior superior escape. So the humeral head comes up and forward as the patient lifts their arm up.

The consequence of that, is that it causes cartilage and bony breakdown, and these seem to release enzymes that further damage the surrounding tissues. And therefore, if you like, the resulting pain and the fact the patient can't move leads to more deterioration in tissue quality and bone quality.

Now there's a classification system called the Hamada Classification System, and essentially this depicts the different stages of progression of cuff tear arthropathy. So first of all, your superior migration of the humeral head, where you get that decrease in acromiohumeral distance, your stage two.

That progresses to that acetabularisation that I described in that stage three, and then finally stages four and five are all to do with glenohumeral joint arthritis.

Essentially you get a big tendon injury contributing to mechanical unloading of the cuff. And because you don't get the normal stressing that keeps homeostasis and the tissue healthy, then we get these different changes due to signaling changes at a cellular level.

Now, when you look at the expert kind of opinions about this and different contributing factors, there's no doubt mechanical factors due to the loss of cuff integrity, commonly associated with three or more tendons. You lose that normal concavity and compression effect. And so again, if you can imagine loading of the joint is altered that humeral head migration, but it's also been associated with people with recurrent instability in later life, often after a traumatic dislocation. There also seems to be nutritional factors again because we've lost that kind of constrained joint space because of the tears. You've got leakage of capsular fluid, so that can impact what's happening over the joint surfaces. That certainly seems to have a role in contributing to cartilage atrophy.

Decreasing water, glycosaminoglycan content, and also collapse of the subchondral bone. So you can actually see osteoporosis in that subchondral region. There are also some authors that talk about crystalline-induced arthropathy, so there have been finding calcium phosphate or crystal deposits.

And that essentially that can potentially be a reason that will destroy the rotator cuff, so as well as just being a result potentially of a massive degenerative cuff tear. It does seem there are some subgroups with some systemic predisposing factors that make them more likely to develop this cuff arthropathy.

Now, if you believe the evidence, it says that it's more common in the seventh decade and more so in women than men. Again, that depends on who you read. But another thing that's important to say is it can also be a consequence after rotator cuff repair, certainly about 11 to 12% of patients having larger, massive tears repaired are likely to then develop cuff tear arthropathy. That's a reported instance. But interestingly, post-operative pseudoparalysis and inability to abduct the arm is one of the biggest predictors of people who have a rotator cuff repair then developing cuff tear arthropathy over the next year or so. When we look at those people with a progressive history that then present with that anterior humeral escape and signs consistent with cuff tear arthropathy on imaging, then often they'll describe a pattern of episodic pain over years that has got worse over time. Episodes have lasted longer, and then they start to develop weakness and this loss of function. So some clear things to look out for. If you see these patients clinically, you'll typically see that prominence of the humeral head. They can have a subcutaneous effusion because of that loss of fluid from the capsule.

And obviously they can have wasting in the supra and infraspinatus fossa depending on which muscles are involved. They generally have significant limitation of active and passive range of movements. They might have crepitus in the glenohumeral joint. People with very progressive disease, you sometimes see this thing called the geyser sign, which is almost looks like a round cyst on the top of the AC joint, and that's because of that erosion underneath that then creates leakage of fluid into the AC joint capsule and gives you this geyser sign. So again, some important things just to look out for.

This is gonna bring me very nicely to subscap because that's obviously a little bit about cuff tear arthropathy. And the fact is, even in people with cuff tear arthropathy who have that pseudoparalysis, there are some people, about 55% that can actually do well with rehabilitation.

And that actually they can resolve that pseudoparalysis and regain reasonable flexion movements. However, the reason that subscap gets such a lot of interest is when you look at those patients who do less well, they are definitely those ones with anterior cuff involvement and significant loss of anterior superior stability.

So very much that kind of coming out at the front when they start to lift their arm up. Authors think this is because we've lost subscap, we haven't got anything to center it. And what's interesting is when you look at patients who do well with cuff tear arthropathy and massive cuff tears, the most consistent evidence still suggests that they're the ones that actually manage to use the remnants of their cuff, so whatever's left of subscap, whatever's left of teres minor, and essentially they then have better potential to compensate. Now there's been one paper recently that's made me challenged that and said it's maybe not that clear cut. But there's absolutely no doubt that expert consensus is that people who have a complete subscap tear are far less likely to do well with rehabilitation intervention and they're a group who might have a lower threshold to get them reviewed in terms of other treatment options. Now as I say, we need to be a little bit cautious because that kind of research is changing a little bit at the moment.

However, you might note I said a complete subscap tear. So one of the things that's really important about subscapularis is it has two key functional parts. It has about nine different pennate, I think, when the last paper I read. But it's a really meaty muscle. I think before I've described it as the big daddy of the rotator cuff because in terms of size, it's actually equal to the other three parts of the rotator cuff. In terms of its attachment, while 60% of it is into a tendon, actually about 40% is direct muscle onto bone. Now, of course, it has lots of functions. It works in co contraction in an abduction with the rest of the cuff. Certainly it's an internal rotator, we all know that, but it also helps in terms of extension and balancing out our prime movers. It also has a role in adduction, and the different parts of subscap are thought to have a bias towards a stability or a mover role.

Now, of course, we know muscles do all things and we get very hung up that we mustn't just think about one bad muscle. But if you've got a subscap tear, it does seem to have some consequences. It's actually the least common muscle in the rotator cuff tear compared to supraspinators and infraspinatus.

And another really important part that can be really useful clinically is that subscapularis tendon tears are more commonly associated with additional rotator cuff or biceps pathology. If you look at subscap tears, 20 to 90%, depending on the literature you read, are accompanied by biceps pathology, which could be biceps subluxation, biceps pain, and disruption of the biceps pulley.

Another really a common associated pathology with subscap tears is what we call an anterior superior rotator cuff tear. Where an anterior supraspinators tear has extended into the superior border of subscapularis, and this represents between nine to 40% of subscap tears.

Now the anterior superior tear, it's basically a lot less common than a posterior superior tear, which is your supraspinatus and your infraspinatus. Now, what's also important to note is when we look at things like ultrasound is not nearly as reliable as picking up subscap tears as it is at picking up supraspinatus and infraspinatus tears purely because of all the other things that are in the way. MRI is better, but it's still not infallible.

Now, when you look at common mechanisms in terms of trauma for subscap tears, the most common mechanisms described are a hyperextension injury. So somebody reaching out to grab something to stop themselves falling. Forced external rotation, similar type of reason and no great surprise people who have a traumatic dislocation of their shoulder. But again, typically in an older cohort. A lot of the subscap tears that then result in these massive tears or progress on cuff tear arthropathy can be degenerative with no particular precipitating trauma. And interestingly, when you look at overuse subscap tears. They're highly prevalent in a lot of our sporting populations. Certainly swimmers, martial artists, boxers. But remember again, they're often partial tears or tendinopathy. They're not frank full thickness tears. So again, when we look at this older cohort, degenerative or traumatic tears, very much we're talking about the mechanisms that I described. Now of course, somebody with a subscap tear is likely to have anterior shoulder pain, but there's lots of other things that can cause pain at the front of the shoulder.

But if somebody's got long head of bicep symptoms with evidence of internal rotation, weakness, and we're gonna talk about some of our subscap tests in just a moment, then again, all these things would just weigh up our suspicion.

Now in terms of testing, I'm sure you're very aware of the Lift-Off Test where you put the hand behind the back. Can the patient lift away and if they can, giving them some resistance. We also have the internal rotation lag sign where again, you lift their hand off if they can keep it there, that's meant to rule out subscap tears. If they can't, then it rules in subscap tears. The problem is that both those tests are not nearly as reliable if pain is a factor. So pain is a confounder because of course you then can get pain inhibition. So we need to be a little bit cautious. The lift-off and the internal rotation lag sign are thought to correlate more highly with testing out that lower part of subscapularis.

Now, in terms of the upper part, our belly press, and this probably shows why those tests can be notoriously unreliable in some studies because they're testing potentially a different part of the muscle, the belly press, where you just get them literally to have their arm by their side, put their hand on their tummy, and basically you try to pull their hand away and they can't.

It's weak. That's thought to rule in more of an upper subscapularis tab. Again, let's be sensible guys. It's all about mechanism, pain, symptoms. 80% is our subjective assessment. These things might just help weigh up yes or no, that we think that's relevant in their presentation. The Napoleon is a similar version where they push in, but their hand arms slightly out to the side and the hands are a little bit further apart.

But the key thing there is that they can keep their elbow forward whilst they push into their tummy. Because of that realisation about testing different parts of subscap, this is where the bear hug was devised from, and essentially originally was described putting the hand onto the opposite shoulder and then don't let me pull your hand away.

They also did another version where the arm was down, so about 45 degrees away from the body and equally looked at saying look, we're looking at upper and lower subscap here. Unfortunately, you can imagine this is almost like an impingement position where we then add resistance and pain inhibition gave a lot of confounding results. So it was found that lower position was much more reliable. No great surprise, a combination of belly press and bear hug or lift-off and bear hug again, depending on whether a pain provocative or not seemed to have more relevance. But as ever, it's going back to that history.

I, as I've mentioned before on these Facebook Lives, have been very keen to look at the cuff in prone because I think that allows me to search it out more. And importantly, see if giving some support to the arm, we can find a place where they can actually initiate some internal rotation force. Because the bottom line is that potentially identifies somebody who might have more potential to compensate.

So guys, that was about our cuff arthropathy. It was also about subscap tears and why potentially they're an issue. And importantly, just some simple clinical things to reiterate in a little bit more detail some of the things that we mentioned in the webinar.

Now we've been blown away by the response to our free webinar, and the Shoulder Steps to Success Online Course.

So guys, I hope you took some interesting things around that. Those of you who have joined, oh, here we go. Hi Jo, it was a nice talk. Oh, thank you.

I have a question. Does this specific diagnosis help or improve in management as the cuff arthropathy comes under the umbrella of rotator cuff related shoulder pain?

Oh, Shah what a great question. So again, what we talked about in the webinar is, actually when you look at massive cuff tears and really cuff arthropathy comes within that population. The bottom line is they are a little bit different only in terms of what I just mentioned before, that if you have somebody with a massive rotator cuff tear, essentially, what the evidence suggests is those patients who do well with rehab are the ones that manage to improve strength in their teres minor and improve strength in their subscapularis or remnants.

So as long as you have one part of your subscap intact, you seem to have better potential to do well with rehabilitation. So unlike our cuff related shoulder pain in this particular cuff arthropathy and massive cuff tear population, there is some evidence that suggests targeting those remnants of the cuff and also deltoid gives us best value.

So I'm sure you're aware there's quite a few papers out there that talk specifically about anterior deltoid strengthening. What we now know, thanks to work from Ofer Levy, Ann Cools is it's not just about anterior deltoid, the exercise approaches that are suggested, so lying down, doing flexion, loading it up, and then gradually glitching up against gravity or doing the same thing with table slides, inflection, and again, gradually working up against until we're kind of a gradient and then a wall slide, and again, loading it up.

Those deltoid programs that have been shown to actually improve deltoid strength in conjunction with targeting those remnants of the cuff actually have good evidence at the moment. It's just how successful they are, can vary anywhere between 40 and 90%. And that's where we maybe need to understand a little bit more about what makes a good outcome and what doesn't.

So I hope that answers that Shah. So I guess yes, we can put them under that rotator cuff related or subacromial pain syndrome, whatever, because that's where the pain is. But if clinically they have clear evidence and a history that's clear and consistent with a massive cuff tear or cuff arthropathy, those are some specific considerations in our rehabilitation.

So I hope that answers your question. Thank you very much indeed for that. That's awesome. There's two lovely papers actually, one by Fahy et al and also so by the lovely Eoin Ó Conaire, looking at a review of massive cuff tears and in terms of some of this evidence in the things that are useful to us as clinicians. And again, they highlight that relevance of whether there's any subscap intact or not.

Thank you for that. Bye for now and enjoy your evening.