Hello and welcome to this webinar on canine muscle and tendon injuries. I'm James, and I'll be your host for the next hour. I'm a specialist, small animal surgeon and also a specialist in canine sports medicine and rehabilitation.
And in this lecture, given that there is a strong emphasis on anatomy, that's where we'll start. So just kind of very briefly I suppose, just wanted to cover the muscles are made up of bundles of fibres. And these then come down and form a tendon which allows the muscle to attach to bone.
And as muscles contract, they pull on the tenderness attachments to bone that can then cause bones to move, and this is effectively how our bodies move. So, I suppose the important thing is just to kind of take away the muscles are made up of multiple fibres. And what we'll come on to later on is that injury can vary both in terms of prognosis, treatment, on the amount of muscle that has been injured.
Also, where the muscle is, is injured, is it along the tendon or is it the mid-body, and what is the, the function of that muscle as well. So don't worry too much about the kind of micro er anatomy. But just understand it's kind of a bundle of separate fibres.
So in regards to injuries, and again we're gonna cover more on injury rather than muscle diseases. There's generally 4 main types of ways in which a muscle or a tendon could be injured. So that's kind of a, a laceration, a contusion, ischemia, and a strain.
So with regards to a laceration, this would be a sharp penetrating wound. And the significance of this can be very variable. So if we have a really important muscle or a tendon, and that is severed, then it might have a real significant effect on the patient's ability to ambulate.
So for example, in this image we have an Achilles tendon that's been completely severed. That would mean the patient would be unable to effectively bear weight on their ankle. They would collapse into a plan degrade stance, and that would have a very dramatic effect on the patient's gait.
Whereas if there was, say a mid-body laceration to a muscle, and only part of the muscle had been damaged, the muscle may still function very well and there could be minimal effect on gait. Likewise, if there was a muscle that was lacerated that is less important for mobility, then again, we may find minimal effects with regards to how that impacts a patient's ability to walk. Next one is, is a contusion and and this is a blunt trauma to the muscles, so no nothing has has sort of penetrated, but we've got pain, swelling, bruising, and this can result in lameness.
Now contusions can vary in severity, so the MRI image here shows quite dramatic effects, but most contusions will be much milder than this, and therefore they can often resolve quite quickly. You can have some things that can be more concerning, but these are quite rare in in our patients, which would be sort of a, If you had a rapid high volume bleed within an enclosed compartment, so this is an area where fascia limits the ability for fluid to move from one area of the body to another, you could end up with a compartment syndrome, and that can have quite severe consequences, but fortunately it's quite a rare occurrence in our canine and feline patients. Something else that's a bit of a an in between, and this is the one that can catch you out.
I've kind of coined it both a sort of a, a laceration and a contusion. Now this is basically sort of a, a non-penetrating injury insomuch as there's no actually open skin wound, but the tissues underneath can become severed. And you might sort of think, well, how can this happen and and I guess it's because the skin has some natural elasticity and flexibility to it, so it can move inwards, whereas a tendon, particularly if it's very tight and taut and strain, can then snap.
And the image might look a bit odd, but it's the underside of a radiator, and, and this I suppose would be a, a good example of when we might see a situation like this where perhaps a dog is sleeping in its bed underneath the, the radiator, keeping nice and warm, and then suddenly the, the doorbell rings and the dog jumps up from its bed, catches the back of its foot, it's kind of metatarsal area, the plantar surface on the underside of the radiator as it goes to propel itself forward towards the door. And the sharp metal doesn't penetrate the skin, but is able to sever the flexor tendons on the palmar side of the metatarsal. So you could actually end up with a tissue that has been lacerated and severed, but no skin wound over the top.
Another potential problem can be ischemia, since we have kind of loss of blood supply to the muscle resulting in the, resulting from the injury, again, this is quite uncommon in our patients, more of a concern in, in us as humans. So, thrombosis, these can occur quite frequently, but they seem to have very minimal, significant disruption in dogs. What I suppose that we'll maybe see more often might be a strangulation injury, so this could be, essentially, let's say for example, unfortunately a bandage that's been put on too tight or incorrectly slipped and moved and constricted the muscle, cutting off its blood supply, causing it to become, injured.
Or it could be if you have a laceration to a vessel that supplies that muscle that could also have impact on the, blood supply leading to ischemia and ultimately necrosis. And the final one, the one I suppose much more common than one we maybe have had come to my mind when we were thinking about injuries to muscles, is a strain. Now a strain to a muscle is where there is tearing of the muscle fibres.
And these can either be an acute injury where it tears very suddenly, or we can also have a sort of chronic overuse strain whereby there are repetitive small strains, small injuries to the muscle that accumulate over time. And the occasion when a muscle is more likely to be strained is during an eccentric contraction. So, if you're not familiar, what do we mean by an eccentric contraction?
So if you were thinking about, lifting up a weight with your arm and you were to tense your biceps muscle, the muscle would get shorter and your arm would come up as you lift the weight. And that would be a concentric contraction. Now if you were to hold the weight in midair, your bicep muscle would be tensing, but the muscle not changing length, it wouldn't be shortening, it wouldn't be getting longer, it would be staying static.
That would then be sort of an iso centric contraction. And then if your muscle was to be contracting but elongate, so this might be after you've done a bicep curl, you're lowering the muscle, you're sorry, you're lowering the weight down nice and slowly, you're contracting your biceps muscle, but the muscle is getting longer. And this is what we call an eccentric contraction, and this is the time when muscles can be most susceptible to injuries.
Now with regards to a strain, it can vary in how severe it is. And therefore we can grade that injury. And the most commonly grading used scheme, particularly in veterinary medicine, is is a 123 grade of scheme.
It's relatively simple but very good in terms of giving us a a a basic idea of what our treatment protocols and prognosis would be. Now you can get more complex grading systems, so this is an example from a a British Olympic team, a human Olympic team and you can see that this is much, much more complex with different grades of strain and relies on various characteristics such as MRI imaging. But we'll stick to the more kind of basic er grading system.
So a grade one strain. Now this is where the actual muscle fibres typically remain intact, so the architecture of the muscle is intact. And the function of the muscle is also intact, so the muscle can still work as it should do.
They're very, frequently very small, isolated, so often described as perhaps less than 5% of the, the muscle, is actually involved. And you end up with some focal edoema, some haemorrhage. And these often resolve quite quickly, usually within a few days.
So quite often if you had a a dog come to you, the client says it was lame for a few days but now seems to have resolved, very likely it was a grade one muscle strain. Now, grade 2, these are partial tears, so not all of the muscle has ruptured, and that means that the muscle can often still function, but you can get reduced strength or reduced effectiveness of that muscular tenderness unit. Now we'll often have a a longer duration of lameness and this can vary a lot.
It, it can vary from sort of days and weeks to months and years. And these are the ones that actually may not completely heal. And it can be quite hard in terms of establishing the, the prognosis for these, and they can be quite frustrating to treat, particularly because the muscle is at is at risk.
A re-injury. So you sometimes can feel like you've made good progress, er, the lameness is perhaps a resolved, the dog's gone back to to normal exercise and then suddenly you're back at square one again. It can be extremely, extremely frustrating for both yourself and for the client.
And the dog. Now a grade 3 strain, this is where you have a complete or at very least a very significant tear to the muscle. And you can then end up with a kind of a complete loss of function.
The muscle just will not work as it should do more. And if that is an important muscle that's vital for for locomotion, then dogs can be left unable to ambulate on that limb or with a severe disability. So for grade 3 strains, because there is a complete rupture to the muscle, complete loss of the architecture, very frequently surgery is indicated for these patients in order to repair the two ends of the muscle or tendon back together.
So here's a little example I suppose of a a grade 3 strain to the sort of gastronemius calcaneal tendon, muscular tenderness unit of this patient. So with the stifle fully extended, you should not be able to flex the hock to that degree. So there is a complete loss of the architecture at some point within that muscular tenderness unit.
So what we'll kind of run on to next is. Tendinitis versus tendinosis, and I'm gonna start off telling you this is very important. I'm then gonna tell you to forget these two phrases and then tell you to remember them again.
So let's kind of progress through what do we mean by tendinitis versus 10 tendinosis. So with tendonitis, something that has itis on the ends, you'll know that means inflammation. So when I suppose we might refer to something as tendonitis, what we're typically referring to is there is inflammation present within that tendon.
So, what typically happens is inflammation can be caused by micro tears within the the tendon structure. You could then have perhaps an acute overload, so there could be perhaps too much force applied to that tendon that that causes it to tear, or it could perhaps be loaded too quickly. The tissue doesn't have time to adapt and the tissue tears.
Now, with regards to inflammation, then we can treat inflammation, come on to a bit more detail. We have a specific way of treating it, and I've used the acronym PRC. So we're gonna treat an acute inflammation differently to a more chronic condition.
And We used to think there was tendonitis as one specific er type of acute problem. And then another condition called tendinosis. And tendinosis is where we would find evidence of degeneration within the tendons.
And it was thought that this was because of essentially chronic overuse, repetitive strains, and also not giving the tendon enough time to heal. And if you end up with a chronically injured abnormal pathological disease tendon, it could predispose the tendon to failing. So our our treatment strategies often for tendinosis, we try to re-stimulate healing, and what would often happen is the tissues would almost kind of give up with healing and there would be no inflammation.
And inflammation, we often think of it as being a bad thing, but inflammation is how the body heals. So if there is no inflammation, the body cannot heal. So often treatment strategies for say ttendinosis would be to re-stimulate healing.
And it was then thought that perhaps tendinitis is kind of a precursor to tendinosis. So tendinitis can become tendinosis if the body is not given adequate time and the environment to heal. So repetitive bouts of tendinitis that are not able to fully heal would then lead to a tendinosis.
But there's no generally a shift away from using those phrases, in part because it's not very well defined, when does, say, tendonitis become tendinosis. So rather than using those phrases, what you've probably come across now more frequently when you hear people talking about these conditions or in newer texts is the phrase tendinopathy. And I guess this is then trying to better encompass the spectrum of conditions that we see.
Within, tendon problems, tendon injuries. And as I kind of said at the beginning, we're looking primarily at at injuries, but we do know that muscles and tendons can become diseased. They can suffer from degeneration, we can have myopathies and tendinopathies.
And these are important to be aware of because these could predispose to failure. And they might also limit or impair the body's ability to heal. So kind of myopathies, tendiopathies and degeneration to tissues tend to frequently be chronic problems.
And what can sometimes happen is they can be an acute on chronic event. So I guess the kind of very common example perhaps might be the Achilles tendon. So the common calcaneal tendon.
Can start to suffer from degeneration. You'll often perhaps notice on dogs that the, towards the insertion point of, of the Achilles tendon, there is quite a lot of sort of thickening. The dogs often aren't lame, they maybe not particularly painful when you palpate that area, but you can palpate or even see that that tendon is, is markedly thickened.
And then suddenly they can acutely decline where they ever become severely lame and there's actually increased planty grade stance where there is actual loss of architecture, tearing, lengthening of the muscular tendinness unit. So we have this acute on chronic. So the, the history is really important in those patients.
And whenever we have a a muscular tenderness injury, we're often gonna start with finding out about the history and that's really gonna help kind of gauge perhaps what happened. So was this a, a chronic problem? Was it acute?
Was it acute on chronic? Was there anything that seemed to happen when the lameness started, so was there an impact, a trauma, which might then indicate that there has been a contusion? Was there an associated skin wound, suggesting that there could be a laceration.
Or if the dog did suddenly happen to yelp or indicate an acute pain at some point, what happened on that occasion, so was it that the dog jumped up from underneath the radiator catching the back of its leg. The other one I remember, being told is about the, kind of older model of Land Rover and dogs jumping at the back of a Land Rover. And on the back of the Land Rover there was a sharp metal lip, and again the dog might catch the back of their leg on that.
So is there anything from what the client describes that could indicate perhaps what might be happening to result in an injury to a muscle or a tendon. We're gonna I suppose move on to our physical examination. And the kind of key things that we're likely to find or look out for might be pain or palpation of the muscle.
They could also be pain on stretch tests, so what we wanna do is manipulate the limb through a range of motion that's going to apply stretcher or lengthening to a particular muscle or muscle group. And if there has been a muscle injury that will often result in pain. It might also result in a change in the range of motion.
So we may frequently see a reduced range of movement to a joint, not because the joint has a problem, but because the muscle that crosses that joint has a problem and does not want to be elongated and stretched. In some situations, like the video of the Achilles tendon rupture that I showed you earlier, we might actually see an increase in range of movement because of a grade 3 complete tear to a muscle. Very frequently, particularly if it's chronic, we'll have muscle atrophy.
On palpating the muscle, we might also have a, a swelling, so an increase in size, or perhaps a, a defect if there is significant tearing, or perhaps necrosis of a muscle from an ischemic event. And again, muscle might feel particularly firm if it is tense from from being injured, er or it might feel particularly soft. Maybe perhaps there is a deinnervation to that muscle.
So, physical examination is, is really, really important in trying to diagnose these and. It's something that I think you get a lot with experience in terms of examining the the soft tissues, the muscles. It's something as vets, I feel we're not particularly well taught, focusing a lot more I suppose on tests and examination of, of joints, but perhaps less so on muscles.
Whereas physiotherapists will do an extremely lot of hands-on examinations of muscles, they're very good with their hands, much, much more sensitive I would say than than vets typically are. So, this is where it can be very good to collaborate with a, a veterinary physiotherapist, or perhaps consider doing some additional training, and particularly consider some conferences and courses that have a, a combination of vets and physios, is, is really, really helpful in order to improve your physical examination capabilities of the soft tissues. And we also have diagnostic modalities and again, particularly with the advances in technology, the more availability of advanced diagnostics in practise for vets to use, there is becoming a bit I think of a an over-reliance on them.
And sometimes I think also maybe a a misinterpretation of what they're actually able to achieve. And I think actually your hands, particularly for muscle and tendon injuries can be just as if not more important than than imaging. So in terms of imaging, what many vets will have commonly available is is X-rays and potentially CT.
Now I will show you some examples later on of where X-rays and CT can be helpful, but obviously, generally, muscles and tendons don't show up well on . Radiography and CT imaging, so they're not the best modalities for diagnosing problems to these particular structures. What can be extremely useful and is probably sort of one of the two gold standards in in human medicine and used very much in the equine side of things is musculoskeletal ultrasound.
It's a very underutilised modality in small animal medicine. Some of the challenges is it's very user dependent and it's very easy to create artefacts, and it's very difficult to interpret unless you are the person with the probe in your hand. So you take an X-ray, you can send it off for somebody else to have a look at, but with ultrasound, that's much more challenging.
MRI again, another one of the kind of I suppose gold standard modalities in human medicine. And in our canine or feline counterparts, the challenge is often size. So a dog's leg, again it varies by breed but is generally much smaller than our limbs and therefore, even though we have the same quality MRI scanners, the imaging quality that you get of a particular, say, tendon or muscle is gonna be much smaller, much lower.
Also, with MRI for example, I have lots of clients who come in and say, oh well, you know, let's do an MRI of the soft tissues. And also many vets refer a patient thinking, well, let's do an MRI for the soft tissues. But what I typically find is unless you catch an injury often very early on, when there is often haemorrhage and edoema, you can see that quite clearly on an MRI.
And if something is quite severely damaged, then again you're more likely to see changes on an MRI. But for the more common perhaps kind of grade 2 strains and injuries to muscles. There's often not a huge distortion to the, the architecture that you see with the muscle fibres on the MRI scan.
So it's often not an ideal way for us to actually see the soft tissues to prove there is an injury there. And I think more often than not I'll probably end up being a little bit disappointed sometimes with MRI in terms of it doesn't give us the the diagnosis that we think it might or perceive that it might. And that can also sometimes be very frustrating to clients.
I'm always kind of telling them upfront that we can do the MRI, but it's no guarantee that it is gonna show us the exact cause, of the lameness in terms of isolating exactly the muscle that has a problem. And therefore I find actually, actually our, our physical examination can sometimes be much, much more better and more useful at pinpointing the source of the lameness. Arthroscopy, again, less useful for muscles but can be useful for some tendons if they have a, an intra-articular component.
So the, the biceps maybe is a very good example. The sort of origin biceps tendon can be seen with arthroscopy through the shoulder. EMG, I suppose a little bit less useful maybe for kind of acute muscle injuries, but can be useful for myopathies, scintigraphy used very, very rarely now.
And thermography, I suppose a bit. Well, is it controversial to say hit and miss? I, I think there is some, use to thermography, but it's something whereby there is a lot of variability, it's not the most, sensitive or specific modality.
So in terms of diagnostics, they kind of all have their sort of pros and cons, both in terms of availability, cost, ease of use, and also how sensitive and specific they are. Now with regards to treatment of muscle and tendon injuries. I suppose this depends on the severity of the injury.
And also if we were referring to that sort of tendinitis, tendinosis phases, it depends where we are in that phase. So if we have an acute injury, inflammation, pain, swelling, edoema, then we're often looking at the acronym price. And what we wanna do is we want to try to protect the injured area from further injury.
So that's very frequently perhaps just rest, so bed rest, stopping walks, short walks, on a lead, preventing running, jumping, anything too boisterous. It might mean using a a bandage or an orthotic in order to limit the amount of movement that that happens. Again, want to, to, to rest, want to try to cool the area, so we're maybe applying a cool pack, some ice.
I also want to try to compress, and there are some ways in which you can actually combine these so you can compress and apply ice at the same time. Either with something a little bit more fancy, like the kind of game ready system on the image in the top right hand side, or it might be sort of using a compressive bandage to to wrap a cool pack over the the injured area. And I suppose again if we look at human athletes, you often see both, you often see the rugby player come off the bit at the pitch and sit on the bench and suddenly they have a, an ice, a pack of, of ice cubes sort of strapped around their leg, or they have something a bit more fancy, perhaps like the game ready system on.
And something that's a bit harder in our canine patients but elevations, so you'd want to elevate the area so that any sort of swelling that forms is, is minimised and and travels back down towards the body. That is very, very difficult in our canine patients and they usually tend to do the opposite with regards to keeping their limbs, distal, and therefore kind of can cause swelling to to pool and increase and worsen. Now I suppose in the kind of immediate acute phase.
You, patients are often going to be very uncomfortable, painful, we wanted to get that to settle down. Once some of that initial pain has settled, then our treatment can start to move on to some manual therapy. And manual therapy can be used in order to try to improve comfort and also try to stimulate healing.
It can be used to try to move edoema fluid away. We can try to soften any knots of built up, we can use sort of cross frictional massage to try to sort of re-stimulate healing, stimulate the the muscle fibres to to heal in a particular way, try to reduce scar tissue formation. And we can also then start to think about a rehabilitation process as well with regards to our exercise and .
Other treatment modalities that will come on to you. Now for NSAIDs and a question mark because it's often our kind of go to in in veterinary medicine that straight away if there is a, a pain, a lameness, we're often giving an NSAID, but there is some evidence that NSAIDs can impair the healing of of soft tissues like muscles and tendons. So there's a bit of a, a, a controversial .
In terms of their use, and the thought process behind their use. I suppose what I would maybe suggest is, again, first of all, we want to reduce pain. And there is gonna be some, you know, inflammation that can be bad, but ultimately inflammation is also how the body heals.
So we wanna try and reduce some inflammation, but maybe not all of it. So I typically would only maybe suggest using NSAIDs for quite a short period of time, and then maybe switch allergies to something else if still required. Now if we have more of a a chronic injury, so again, maybe using that kind of tendinosis phrase, what tends to happen is the body stops trying to heal and there is no inflammation.
So we're often trying to restart a healing process by reinitiating inflammation. And a way in which we can do this might be with the use of sort of orthobiologics. So this is just sort of regenerative medicine, things like platelet rich plasma, stem cells.
These are trying to cause some inflammation, release cytokines, growth factors that are trying to help these tissues to heal. We can also use things like certain types of ultrasound, sort of shockwave might be an example. And the way I think about how these can help is they are trying to almost inflict some micro damage to the tissues, or at least make the body think they are being damaged and therefore the body will start to release more of its own endogenous healing growth factors, cytokines, er, its own endogenous opioids in order to improve comfort.
And we can also, consider the use of a laser to try to up-regulate these processes. Now, the prognosis can be difficult to predict, or it can at least be very difficult for me to advise very quickly in a lecture what the prognosis is because it can vary dramatically depending on the severity of injury to a muscle or a tendon. It can also vary depending on what muscle or tendon is injured and also ultimately what the function of that patient, that canine has to be.
So if you have a chronic severe injury to a patient that needs to perform at a high level, then the prognosis is gonna be poorer than perhaps a patient with a more short term milder injury that doesn't have to do very much exercise. So the prognosis can vary and the prognosis can be perhaps sometimes challenging to predict, particularly because there's not a great way of grading a say injury other than 123, but there can be a huge subcategory with regards to grade 2. Patients can respond differently to treatments.
But I think what really is key with muscle or tendon tendon injury is rehabilitation afterwards. So we need to have a rehabilitation programme that is going to protect that tissue from being re-injured, and that can include trying to re-strengthen the muscle, improve flexibility of the muscle, improve patient proprioception, so they are using that muscle more appropriately and less likely to manoeuvre themselves in an abnormal way that could put additional strain on that muscle or tendon. And it might be a case that this is done with physiotherapy, it might also be the use of hydrotherapy and also having a, a controlled return to exercise programme whereby we're gonna build things up slowly and we're gonna build things up at an appropriate level for that tissue.
So we know that muscles and tendons can take a long time to heal and therefore we don't want to overload them too soon. So we need to have a very careful kind of return to fitness and return to activity rehabilitation protocol. So let's have a little look at some case examples.
We'll kind of manoeuvre our way around the patients, so let's start at the top, at the front, let's start at the shoulder. Probably one of the more common er areas for canine patients to have a muscle or tendon injury. So if we start, I suppose, right at the front, we have the supraspinatus.
And superspinatus can suffer problems more frequently from a repetitive strain injury. So we can end up with kind of a grade 2 strain. And in these situations, there's frequently again no inflammation.
And what can happen is as the body starts to scar and heal, we can sometimes get mineralization. And this is something that can be picked up on radiographs and CT. And sometimes this can be a source of pain and lameness, but also sometimes this can be.
Asymptomatic, or at least not the underlying main cause for the patient to be lame. So if you do see a mineralization on a radiograph in the region of the supraspinatus, bear in mind that could be causing the patient's lameness, but I would often have an open mind to think about other causes elsewhere. And for me, I suppose the most common scenario that I come across is patients with elbow pathology.
So developmental elbow disease, AKA elboid dysplasia, and very frequently we'll diagnose this using CT imaging and very frequently we'll come across mineralization towards the insertion of the supraspinatus. And I don't think there is anything necessarily that kind of proves this, but my own personal theory is that patients with elbow pain are going to compensate and use their muscles differently. So they'll want to move their elbows in a different way, in order to compensate, they'll have to move their shoulders and rely on their shoulders more in order to ambulate.
So my theory is that they're gonna overwork their supraspinatus muscle in order to bring their limb forward, and this is then gonna perhaps predispose to that muscle becoming overworked and therefore injured, therefore scarring, and therefore developing these heterotropic mineralization. So this is what that can look like, sometimes they can be quite mild and small, sometimes they can be much more notable, so you can see this mineralization just in front of the Greater Chicanta on the proximal humerus inside the orange circle. Now, this is what you'll probably come across if you think about a radiograph, often a lateral radiograph of the shoulder, you'll see a mineralization like this.
But because a radiograph is a 2D image, you can't assess depth. So on a, a lateral radiograph, you can't assess how medial or lateral this mineralization is. But with cross-sectional imaging like CT you can do that.
So again, here's two examples, and you can see the mineralization is in different places. The image on the left-hand side of your screen. The supraspinatus mineralization is very cranial, whereas the image on the right of the screen, the mineralization is more medial.
I can see that they're inside those orange circles. And This is something that again you can see on radiographs if you take a skyline view. But the skyline view is sometimes difficult to achieve and not something that is routinely done, but if you are finding no cause of lameness elsewhere then.
This and finding that there is some pain, discomfort on shoulder, supraspinatus, biceps region, then having that skyline radiograph can be helpful. But again, that's often now superseded by CT. And actually what is perhaps better for assessing the supraspinatus because a lot of the time it won't mineralize and therefore you won't see it on radiographs or on CT is to use MRI which is the image on the left, we can see this thickened supraspinatus insertion on the, the greater tubercle of, of the humerus.
Or the image on the right is ultrasound, and we have this sort of classic bird's beak, image or projection where that supraspinatus is inserting. So in terms of supraspinatus pathology, in terms of treatment, again, for me, I suppose I'm a bit biassed in the fact that I'm typically seeing patients with a more of a, a chronic injury rather than acute first line like you might in general practise. So I'm typically often trying to restart a healing process.
So for me, I'm frequently using things like platelet rich plasma, potentially stem cells. PRP is typically much. Easier, more rapid to to apply, also a bit less costly, so sometimes consider that, but stem cells as we come on to can also be considered.
Trying to stimulate inflammation, so we'll often use shockwave and there are some publications showing that shockwaves can be quite useful for soft tissue injuries around the shoulder, which is gonna again be predominantly supspinatus. I might also consider something like laser. In terms of laser, again I'm I'm somewhat a little bit dubious as to really how effective it is.
In regards to how much bang for your buck do you get? It, it does work, but does it work just a very small amount, or is it enough to really have a, a real clinical impact in our patients? But that's maybe something for another time, but if we're trying to eke out as maximum performance that we can, then we can also include that in terms of a modality of treatment.
And I mentioned a little bit about stem cells, so there was publication from from the KNA Group showing the use of combination of PRP and stem cells, er, and they saw that this was beneficial, er when they looked retrospectively in terms of assisting with the healing of supraspinatus, er, tendinopathies. Now I showed you some slides whereby I talked about the position of a super exponentist mineralization can vary. And this is why it's important because there is a close relationship between the supraspinatus and the biceps.
So we can see from our anatomy textbook on the left, we can see those. And then the image on the right, again, that's showing you a cross sectional transverse image through the proximal humerus. And we can see that the mineralization of the supraspinatus is encroaching.
Where the biceps tendon would run, and you could then easily see how they could be perhaps impingement and rubbing. And probably historically a lot of the time. Vets would diagnose a biceps problem thinking it was just the biceps, but probably it was actually a, a pre-existing or an underlying supraspinatus problem that was then impinging on the biceps.
So if we look inside arthroscopically, that's what the image on the left is showing, you can see a bulge, and this is the sort of supraspinatus bulge where there's a mineralization that's then bulging in towards the joint. And when this arthroscopy image is taken, during the arthroscopy, the joint is inflated with fluid, so that's actually pushing tissues further away. When you remove the, the fluid, the tissues would, would come back down closer together and we can actually then see this bulge pressing against the, the biceps.
So, er, looking for for biceps pathology, again, MRI and ultrasound in particular can be useful, and ultrasound can be very good because you can manipulate the joint and and move the joint. You can see then how the biceps moves in some relationship relative to the, the supraspinatus. But arthroscopy can be very good at evaluating the degree of pathology to that tendon, particularly at its, well, obviously at its insertion, sorry, at its origin on the supraglinotubercle.
And what we can see from this arthroscopy image is how the biceps tendon moves up and down through that groove, so it goes down and and up, and there is this movement. And as that is mobile and moving, something that we can have is new bone forming within the groove of the humerus. We can see these little spurs of bone forming again that can rub and impinge on the biceps, causing it to become inflamed and.
In terms of, . Our treatment and diagnostics again we may consider arthroscopy either with a a traditional arthroscope, or what we now have available and we'll use more frequently is a, a needle scope, so much, much smaller arthroscope, as you can see that again, particularly for say a diagnostic arthroscopy, we could do this with a kind of minimal clip, minimal preparation. Very frequently the patient's just heavily sedated rather than a full anaesthetic.
And therefore it can be done on a, on an outpatient setting with minimal, invasiveness, minimal morbidity, minimal pain, minimal risks for the patient and still allow us to actually observe these intra-articular tissues. Something else with the biceps then is gonna do our kind of bicep stretch tests, so if we were to put the shoulder in flexion, the elbow in extension. And again, if we have an injury to the biceps, they can often be painful on this.
Or what you might also come across is if there's a complete rupture to the biceps, then you can see that that has occurred in the image on the right hand side. So that's the dog's left limb and what we can see is that we're actually able to extend that limb out fully straight, whereas if the biceps is intact, we'll end up with this more zigzag degree of range of movement. Now with a grade 3 injury, and this is the interesting thing with grade 3 injuries, patients can often be more comfortable.
So with a grade 2, the muscle or tendon, there is still architecture that's intact, and that's often getting pulled on and can be a source of pain. Whereas grade 3, actually sometimes they can be pretty comfortable. And actually in this dog, this complete rupture to the biceps was somewhat of an incidental finding.
This wasn't actually the cause of the patient's problem and lameness. Doug was actually lay in in the other leg for for an elbow problem but we diagnosed this, this biceps rupture. And actually one of the treatment modalities for a biceps tendinopathy is actually to transect the biceps.
And either you can just do a complete tinotomy, or you can do a tinotomy and a tenodesis whereby you cut the biceps and kind of refix it to the proximal humerus rather than to the scapula. Or you can just, just cut it and leave it and and actually surprisingly patients often will do very well with just a tinotomy. This can be done with again a minimally invasive approach, it can be done arthroscopically, so a kind of a a a quicker recovery in that regard.
In humans, you're probably more likely to have a tenodesis partially from a cosmetic point of view. So in a human, if you rupture your biceps, often your biceps, will actually shorten and the muscle almost kind of falls down your arm. And you then end up with a, a bulge lower down your arm.
Which cosmetically is not, quite perhaps as appealing, and I suppose biceps ruptures much more common in perhaps a bodybuilder than your average human. And for bodybuilders, they want to have a good looking biceps, so, probably more likely to have a tenodesis if you're a human, rather than a dog. In dogs, we tend to find much less dropping of the muscle, and cosmesis is usually minimally changed and it is obviously less of an importance in our canine patients.
So another muscle tendon problem that can affect the shoulder, er is sometimes coined medial shoulder syndrome. Now effectively what this is is a strain to the subscapularis muscle on the medial side of the shoulder and a sprain to the medial glinohumeral ligament. So there on the medial side, it's kind of a sort of V or sort of Y shaped ligament.
The CT image in the centre, we can see that there is some inysophyte formation on the medial side of the glenoid, again, where there has been, an injury, and then there is some mineralization as it has scarred. And arthroscopically, a portion of these tissues can be viewed. So what you can see at the very top of the image is the glenoid.
Then you have the, medial glenohumeral ligament. Behind it is the subscap and then the humeral head at the bottom. And in terms of our clinical examination findings, what we'll frequently come across is that there is pain on abduction of the shoulder.
And also pain on maximal extension, so the subscap is also involved in flexion of the shoulder. So if you extend the shoulder, you will have some pain. And if you are doing an abduction test, I always recommend that you put the shoulder into full extension before applying your abduction.
And classically, these would be a repetitive injury, so the kind of textbook example might be the agility dog that's going in and out the weaves, rapidly changing direction. It's a eccentric contraction to the muscle and it's, then susceptible to repetitive injury. But I've also seen quite a lot of breeds who are definitely not agility dogs having medial shoulder pain and and damage to the medial structures and these can often be, Sort of small but heavy dogs, so for example, your, sort of miniature dachshund, er Lassarapso, these sort of chondrodystrophic breeds, short legs, but perhaps relatively increased body weight.
And the reason why I think I come across patients with medial shoulder pain is that they spend a lot of time jumping down from the sofa onto a smooth floor. Where people often have laminated floors, these dogs can often be little sort of, short man syndrome, angry dogs, the doorbell rings, they jump down, run to the door yapping, and as they jump down from the sofa, they land on their front legs, go to change direction rapidly, and they're therefore putting sort of sprain strain injuries to the medial support structures of the shoulder joint. So again for sort of treatments, er, often looking at sort of, you know, protection, so that might be the use of some hobbles.
These can have some downsides, but can be a way to try to protect the medial shoulder. A, a lot of rehabilitation therapists are coming a little bit out of favour of these because they feel that they can cause other compensatory problems, but this is again an example of trying to protect the tissues whilst healing and then trying to re-stimulate a healing environment with the use of or biologics and and potentially sort of shockwaves as well. Now with that sort of medial shoulder syndrome, that's typically a grade 2, sort of strain injury.
Whereas a grade 3 injury would result in instability. So this would be where you'd have a complete tear, an unstable joint, and this is where you would have an increased abduction angle. So with grade 2, often the abduction angle can be the same.
But they're painful on abduction, whereas with a grade 3, they can usually have quite marked increase in abduction angles but can often be quite comfortable. Now with regards to grade 3 injuries, we're perhaps gonna be thinking more towards surgical repair, less likely to be thinking about surgery for grade 2 injuries. And with regards to medial shoulder instability, we may want to assess the degree of instability by measuring abduction angles.
So the dog that's the kind of cream coloured dog that's on the top, we have two limbs and you can see that the image on the left there's a much greater degree of of abduction. And comparing it to the other side. Now sometimes you can have a subtle increase in abduction, not because there is a tear or injury to the structures on the medial side of the shoulder, but because there is a reduction in muscle mass.
So if you have muscle atrophy to a limb, and that could be due to a problem anywhere in the limb that's been causing some disuse, you may find that your abduction angle can be increased. So just kind of bear that in mind that if it's a subtle increase, it might be because of muscle atrophy. If you have a marked increase, then it's much more likely that there is a tear.
And you can take measurements with goniometers and there have been some publications published, but what we do find is there's quite a lot of variability between dogs. So actually the figure that you get on the goniometer is perhaps less important, more important to maybe compare one side to the other. And in regards to surgery, we're often then trying to use a sort of a prosthetic ligament or an implant that's gonna protect the tissues whilst they heal, so that might be using a a tightrope implant like in this radiograph.
So let's move on, from the front to the back. So the kind of lower back hip region, again another place we can commonly have muscular tenderness injuries. Er a kind of a quite well described would be the ileosoas muscle.
So this muscle originates from the sort of ventral aspect or ventrolateral aspect of the spine, traverses under the hips and inserts on the proximal femur. So we can see an MRI image of the ileosaurus muscle on the left, and the anatomy image on, on the right. And You can sometimes spot that it could be perhaps some ilosois pathology on radiographs and CT by looking for inhesophyte formation at the insertion.
So we have CT images and radiographs for this patient, and on the left-hand side you can see that . There is almost kind of no or no exaggerated lesser tracanter, whereas on the right hand side we can see this new bone formation at the insertion point of the leosauus, on the lesser tracanter. Now in terms of injury to the EosoS, again it's often er the kind of classical example we might think of would be the agility dog jumping over the jumps and having an eccentric contraction to that muscle, causing it to tear, most likely because of repetitive injury rather than a one-off contraction, but more likely repetition over time.
But this could also have a problem er in a dog that's not necessarily doing agility in jumping, but it might be doing a lot of jumping, say, into the back of the car, on and off the sofa. It's that sort of jumping movement, it is often the time when we're perhaps more likely to injure it, particularly if the dog miss times a a jump and and has to try to re-adapt and and therefore is having to contract that muscle, very sort of suddenly when it wasn't planning to. Another time where I'll come across ileosois pain and particularly kind of lower grade injuries, is secondary to something else.
And I see this very frequently, that patients come in for problems elsewhere and there is perhaps pain on the ileosois because it's a secondary compensation. So one example would be lumbosacral pathology, so lumbosacral degenerative stenosis. Patients will frequently use their ilosoas muscles more in order to change the posture of their spine and their back, that will then overwork the muscle.
Likewise, if you have a problem in a pelvic limb, say a hip problem or a stifle problem, dogs will perhaps no longer want to propel themselves through that limb, using muscles like the the gluteals, but instead will sort of pick up and pull their limb forward using their hip flexors such as the areas so so they can kind of overwork those muscles. Treatment for Iosau injuries is predominantly gonna be rehabilitation. That's gonna be the mainstay of treating er injuries.
If you have a very focal injury that you could identify on musculoskele ultrasounds, then you could consider focal, injections of PRP also stem cells and PRP, but for the mainstay of patients, it's gonna be a case of rehabilitation, so, . Referral to a veterinary physiotherapist or if yourself, you are a veterinarian who is able to advise on rehabilitation strategies, that's gonna be the best way to to get these patients to improve. Again, like a kind of classical, muscle problem, a little bit kind of poorly understood, perhaps due to repetitive micro strains in, in the muscle, but guis contracture.
Again, this is a bit of a, a nightmare for us because it's very, very difficult to treat. Actually, I suppose I should say it's probably more likely impossible to treat. I think doing a very, very frequent stretching exercises can perhaps slow down the progression.
But this is a real, really frustrating condition for our, our canine patients. Surgery in terms of kind of cutting the muscle out, it just is, has a very short term impact. It tends to reoccur.
And the use of regenerative medicine into the muscle, there was this publication that came out that seemed to suggest some promising results, but my own experience and experience of chatting to many other vets is that they perhaps don't seem to get the same degree of perceived improvement as what this paper reported, so . A very, very frustrating condition. Moving down the leg, here's a little case example of a patella tendon problem.
So in this patient, the dog had suffered a laceration to the skin, er over the knee, went to the primary care vets, and they saw the wounds and they treated the wounds very well in so much as they cooked the area, they cleaned it, they stapled it closed. But didn't quite understand why the patient was still non-weight bearing lame a week later after having a a skin cut. And if we have a skin wound, it's always important to think about using your sort of X-ray vision, er what is underneath, and if there is any important structures such as the patella tendon.
So on the radiographs, the image on the left, that's the kind of contralateral, it's actually the right stifle, looking very normal, whereas the image on the right of the screen, the left stifle with the radiographic marker, this is the affected side. So you can see the skin staples where the wound was stapled together. And you can see there is some thickening to the patella tendon and the associated overlying soft tissues.
And if you pay close attention, and this is the really key bit, and you look at the distance between the patella and the tibial tuberosity, you'll see that distance is much greater on the image on the right. And this then lets us know that there has been a significant disruption to the patella tendon in order for the patella to move away from the tibial tuberosity. And indeed if we have a little look with ultrasound, the image on the left being the normal side, and there is that darker band er traversing horizontally across, that's the patella tendon.
Whereas the image on the right is the affected side, and we can see running from right to left, we can see that dark area of the patella tendon, but then we have this thickening, this discontinuation down to the tibia. So we have a, a tear grade 3, sort of strain, I suppose, this kind of laceration injury, complete loss of function. So for this, we are going to head to theatre.
To surgically repair. So, this is what we have intraoper is a complete transverse laceration to the insertion of the patella tendon. So for this we are going to consider surgery.
But it's really important to remember if you do have any trauma, a laceration to the skin, think about what could be underneath, what muscle or tendon could be damaged. So for this patient did a a repair of the the primary repair of the tendon and also augmented that using an internal brace system in order to support the repair and then used a transarticular frame to provide greater stability to the repair for the initial few weeks of recovery. Moving down the leg, let's have a look at the Achilles tendons, so.
You might remember that video I showed towards the beginning of kind of a complete grade 3 injury. So here is an example of how that happened. So this is something that can be quite useful now in terms of establishing how a patient may have suffered an injury, is that many people have cameras around their houses, either indoors or outdoors looking at their gardens, and sometimes this can pick up what our cats and feline friends get up to when we are away.
So, this night vision camera on the left hand side of the screen on top of the the kitchen unit, there's actually two cats, and we need to keep an eye on that cat and see what happens. You see the cat now starting to move. And unfortunately the cat tries to climb up on a wooden chopping board that's on the draining rack and it falls.
And unfortunately for this little cat, Zimba, the dropping board fell down onto the back of the Achilles. And that caused the Achilles to rupture. So this again is almost a you know, grade 3 complete failure of that Achilles.
So for this again we have a complete loss of anatomy er in terms of its completeness, so something that can change anatomy is is surgery and something that can repair anatomy and put anatomy back to where it should be is surgery, so we opted for surgery in this patient, so we went in and I did a a primary repair of the tendon. And then I wanted to support the tendon whilst it healed, so for for Zimba, this actually happened not too long after lockdown. For COVID and I needed a strategy that would support the hock without the client having to come back and forth for lots of checkups.
So I didn't really want to have a bandage in place, and I didn't really want an X fix in place. And I didn't really want a calcaneal tibial screw because there's always a worry that they may break and and fail. So I came up with this idea of placing a plate as an internal sort of stabiliser via a minimally invasive approach.
So a small skin incision top and bottom, tunnelled the plate underneath, inserted 3 screws above and below, and then closed with a single stitch and. The plate was then in situ for a number of weeks in order to prevent the hock from flexing whilst the injured tendon was beginning to heal. And then around 5 weeks later, again two small stabbing skin incisions and the plate was taken back out, and then the joint allowed to move and had a very good outcome with, with that case.
In the same, region of the patient's anatomy, so looking at the hock, another muscular tendon injury could be a SDFT luxation. So the superficial digital flexor tendon runs down the back of the hock over the back of the calcaneus, and if the retinaculum that supports it tears, then this can result in a luxation of that tendon. So we've predominantly looked at tendon injuries and actually I suppose, you know, injuries to the muscle or the tendon itself.
But sometimes you can have an injury to tissues around that muscle or tendon that causes the muscle or tendon to work in an abnormal way and resulting lameness. So this dog was, was skipping as it was walking as this tendon was popping in and out. And these are quite satisfactory when you, when you pop this in and out and you you you feel it and diagnose it.
Particularly when the patient comes in via neurology for an unusual skipping gait and they decided to take, you know, just a a a few radiographs just to kind of what they thought, rule out any orthopaedic disease and er cos the neurological exam seemed to be fairly normal. And they were glancing across at the radiograph. You just notice a subtle thickening.
Sort of kind of cordal to the calcaneus and then when you go and put your hands on, you feel this popping sensation. So for, for, you can do an ultrasound, and you can actually then see the tendon pop in and out. But given that it's right underneath the skin, you can obviously, you know, physically see it with your eyes popping in and out like in the video.
There is this little smooth, quite shallow groove on the back of the calcaneus, and I find that just for me, repairing the retinaculum has generally had very good success. Some people describe trying to deepen the groove that the, the tendon sits in. But when I actually open these up and you feel how ultra smooth that, that bone tissue is, it just feels wrong sometimes to to actually try and to bride that.
So I'll do a repairer and then support that with a orthotic for for a period of time. So the the cat that had the mishap, er Zimba, er went on to make a full recovery and was able to go back on to climbing up over the neighbour's fence. And what we've kind of covered in this webinar is again the different types of injuries to muscles and tendons.
So we looked at laceration, contusion, ischemic necrosis, and er the one that's probably most common is is a sort of strain and sprain injuries. We also sort of went through how injuries can initially. The .
Initially we have lots of inflammation going on, and our treatment is then ultimately trying to reduce perhaps that inflammation or curtail the negative effects of the inflammation. Bearing in mind inflammation is also how the body heals, and ultimately if we have a a chronic problem, that doesn't have a chance to heal appropriately, that healing response can start to wither and go away. And then our treatment is aimed more at trying to restart, reinitiate inflammation, to reinitiate a healing process.
So, I hope that you've picked up some useful tips and tricks that will help you in practise. And if you do have any questions, just feel free to to reach out and get in touch. You can either contact me at Fitzpatrick Referrals or get in touch via social media.
I'd be more than happy to try to answer any questions that you have. So thank you very much for listening. Take care.