Hello and welcome to this webinar on canine arthroscopy. Now arthroscopy is one of my favourite subjects, so I'm really delighted to talk about this with you. And share with you some tips, as well as some indications of when arthroscopy can be indicated for your patients.
We'll run through some conditions that can be treated arthroscopically, and then also give you some more details about arthroscopy itself, so you have a better understanding and if it's a technique that you're looking to implement or improve yourself, give you some more information of at least how I do arthroscopy and perhaps you can pick up some little tips and tricks that will help you as well. So I'll be your host, I'm James, I'm a specialist in small animal surgery and also canine sports medicine and rehabilitation. Now a little disclaimer, I am a consultant for Arthex, but I do not receive any royalties.
However, you will notice that lots of the examples that I've used within this webinar are Arthex products, but other arthroscopy equipment from other manufacturers is available, and I'm just using these images as examples. So why might we consider arthroscopy? Well, what we want to do with arthroscopy is have the ability to look inside joints.
And then whilst we're looking inside joints, can we also do arthroscopic procedures to adjust intra-articular tissues? So as with any underlying orthopaedic problem, it's all gonna start with taking a history, doing our physical examination, and then seeing what's the next best step for the dog. And frequently we will go perhaps to imaging first of all, as that is less invasive, and then based on the imaging findings, then perhaps consider something like arthroscopy, as that is obviously an invasive procedure, albeit minimally invasive.
However, it depends on the user's experience and ability. Now there is a potential to cause damage with arthroscopy, the same as any procedure that has any. Internal intervention, so we do need to be, be careful and I'd recommend becoming, well trained, doing some practical courses beforehand before you start arthroscopy yourself.
So if we were going to use an arthroscope, there's different components to it. So we'll run through some of these so you have an idea. So we have the arthroscope itself.
This is. The arthroscope here, er whereby this is our, our lens to look down inside the joint. And then in order to insert the arthroscope, we have a couple of instruments to allow us to do that.
So we have a sheaf and we have an obduator. So the obduator first of all goes inside the sheath. So we would take our obduator, place it inside the sheath, and then this would have a pointed end that can allow us to penetrate into the joint.
Then what we can do, and I'll show you this later on, we can take the obtuator out, leaving the sheath in place, and then inside the sheath we can place the arthroscope. Then attached to the arthroscope, we have the camera head. So that the camera head is the, the device that we're going to often hold onto and that is gonna convert the image to the video monitor.
And it has the ability of allowing us to take photos and videos and adjust things like the zoom, the focus and the brightness all from this hand piece, so that's what these little buttons and and little dials are for. They allow us to make these adjustments. So the image then travels to the sort of imaging platform.
This is what's connected to the camera. And the imaging platformer also can act as a light source. Because we want to shine light inside the joint so we can illuminate and see.
And the imaging platform also then allows us to have sort of a an image management system whereby we can store the images and then they can also be transferred to a larger pack system. So from our light source, we then have a light cable, so light will travel down along the cable to the camera heads and the the ostroscope. So, need to be careful, these are fibre optic, so we don't want to bend them, so we can kind of put them in a loose curl like this, but we wouldn't want to bend these tight because you can break the little fibre optics.
And this particular one you can see in this this image in theatre how it's light lit up. So this means that we can actually see the light going through the cable, and if you were to break any of the fibre optics, you'll be able to actually see that. And it also looks pretty cool.
It's a little disco light in surgery as well. And then the other thing that is important for arthroscopy is for us to have a fluid pump. So the fluid pump allows us to pump fluid down to the handpiece and through the cannula.
So the the the sheath that we talked about earlier, that allows fluid to flow down inside the joint. And we have a fluid pump that allows a continuous flow of fluid. We're able to set flow rates and also the pressure of the fluid.
And one of the main advantages of this is it allows us to keep the end of the camera clear so that we can have a nice image inside the joint. And it also allows the joint to be distended, so we've then got more room to manoeuvre and work inside the joint. And then if we were to perform arthroscopic treatment, we can have devices in order to allow us to do that.
So we might have some motorised equipment such as shavers and blades and burrs that allow you to resect various tissues, and then we can also have various other hand instruments. Such as sort of forceps, graspers, scissors, to allow us to perform procedures inside the joint. And then to keep everything together, we often have a tower.
So this would be a stack where all this equipment is, is stacked on top and that can then be kept in theatre or manoeuvred from one theatre to another, and to keep everything together. So now we've got a bit of an understanding as to what the equipment is required for arthroscopy. Now let's have a little look at some of the indications for why we might perform arthroscopy in our canine patients.
So one of the most common joints for us to assess arthroscopically is the elbow joint. And one of the most common elbow pathologies is developmental elbow disease. So this is kind of several different developmental abnormalities that can lead to a range of pathology.
And it's often referred to as elbow dysplasia. That's the phrase that you probably know and that clients will probably have have heard of. And generally it's to do with an a mismatch in the shape of the fit between the three bones that make up the elbow, the radius, the ulnar, and the humerus.
And if these three bones don't fit together, this can lead to pathology that can cause pain, lameness, and then subsequently osteoarthritis. So you may have seen this image before and I'm not entirely sure where it originally comes from, but it's a great image cos it shows you where some of the problems are with that occur with developmental elbow disease or or elbow dysplasia. And therefore, if you know where these problem areas are, you know where to look on your imaging as to which bit of anatomy could be abnormal.
So you'll see that there's a a few letters written on here, we've got the FCP which is kind of shortened for a fragmented coronoid process. So this little red area is the medial coronoid process and that can fragment. At the back then we've got UAP an ununited anineal process, so that's where part of the anineus doesn't fuse onto the rest of the ulnar, so that'd be the area to look at.
And then OCD, osteochondritis disscans. This occurs on the medial aspect of the humeral condyle. So that'll be another area to look with your imaging.
So those three areas. So if we were to talk about developmental elbow disease or elbow dysplasia, the way that I tend to talk to clients about this is saying that it's the three bones of the elbow joint not fitting together perfectly, causing some increased rubbing in pressure in a certain area. And the analogy that I use is shoes.
So it's like having a pair of shoes that don't quite fit you perfectly and they start to rub. So the most common sort of subcategory of elbow dysplasia would be medial coronoid disease. And this is where we have friction of the humerus and the radius against the medial coronoid process of the ulnar.
So what we then have is an increased pressure within the bone of the medial crinoid process. This causes the bone to adapt with Wolff's law and it becomes hardened and more sclerotic. As the bone becomes more dense and sclerotic, it can become more brittle.
And then we can start to get microfractures forming within the subchondral bone. And if enough of these little microfractures come together. A Little bit like cracks in the ice of a frozen lake.
Suddenly they come together and coalesce, and the ice splits or the bone splits, and we can develop a fissure within the medial cooid process, or that fissure can go on to actually fragment. And that's where sometimes the phrase a fragmented coronoid process comes from. Now what we've talked about so far is the bone, but on top of the bone we have the cartilage, which is a nice smooth surface that allows the joint to move against, to move smoothly.
And if we do have increased pressure, we can also get wearing away of the cartilage, same as the rubber on the brake pads of your car can wear away if there's excessive force. So this is the location of the medial coronoid process. And what this would look like if it starts to fragment on a CT is we would see this little fragment as shown in the orange circles.
And the images on the right show this micro crack formation, and the electron microscope image shows actually a crack within within the bone. And we tend to see sort of different patterns of fragmentation. And sometimes we can have I mentioned earlier, have just a fissure, and sometimes we can have a fragment.
And if you just have a fissure, that can be just as painful for dogs as having a fragment. And actually, in my experience, I've seen lots of dogs who seem to be more painful with a fissure rather than a fragment. So it might be actually there's increased pressure in the bone with the fissure, and that's somewhat released when it when it fragments.
So the different categories of of fragment and fissure, so this is an advantage of arthroscopy. It allows us to see this very nicely. We can have a tip fissure or fragment or a radial incisor fissure or fragment.
So the first image here, we can see this kind of fissure running across just affecting the tip. So this would be a tip fissure. This then semi-circular fissure would be a radial incisor.
And something that's a bit in between, so a little bit semicircular, but extends beyond the tip, then that would be a combination that we tend to call a radial incisor tip or RIT, and that is the most common. So in terms of our diagnosis, some one of the first things we would see would be some subtrochlear sclerosis of the ulnar. So this is where we have this increased whitening and loss of trabecular pattern within the medulla of the ulnar.
The next common thing we'll maybe see is some osteophytes around the joint. So if we saw these on radiograph, we may then want to try to confirm our diagnosis. So the actual tip of the medial conar process is extremely difficult to see on radiographs.
You can sometimes get an idea of faintly seeing where it runs, and it might then look a little bit less distinct, less sharp, and that's often because it has fragmented and and shifted. But a better way to see this non-invasively is with CT. And with CT we can then see fragments and fissures.
So if we have this, then if we went back to our shoe analogy, this is what I tell the clients would be like a little bit of the inside of the shoe breaking loose and acting like a stone in your shoe. And if you had a stone in your shoe, you could elect to walk less, you could take some pain relief, or you'd probably take the stone out of your shoe. And we can do a similar thing with arthroscopy, we can go and we can remove the fragment.
So that's what we can do. We can go in arthroscopically and we can remove the fragment from within the elbow joint. So that would be fragment removal.
Now, on some occasions, the piece of bone hasn't actually fragmented and is just a fissure. But what we can do is go in and remove that abnormal area of bone and cartilage, and that is called a subtotal coronoid ostectomy or SCO. So how do we do this?
Well, when we go into theatre, I tend to position the patient like this on their back in dorsal recumbency with a hanging limb prep. And this will be an example of a dog just having one leg operated on, but we can do the same process for both at the same time. So we'll have them hanging on their back in in this position.
And then what I wanna do is I wanna have a fulcrum to lever the limb off. So what I use is the sandbag that's wrapped just to keep the sandbag clean and dry, and then we're able to lever the limb over this. And then we would drape the patient with with a full quarter drape.
In reality, we tend to often drape the patient first and then slide the sandbag underneath, but I just wanted to show you this image so you can see what it looks like without the drape in place. And then what is super, super helpful is to have an assistant. So you need to be able to lever the joint open, and, and for me I find the easiest way to do that if you have the luxury of an assistant, they can do that for you.
And it means that because the limb isn't secured in place, which is what some people will do, they'll kind of secure the limb in a set position. This then gives us the freedom to be able to move the joint with much more flexibility. And what we're aiming to do is I try to have the elbow and the carpus at roughly 90 degrees.
And then we want to be able to increase the space between the humerus and the ulna, similar to what this diagram is showing where we're opening this space up and we can do that by pronating the limb. So if we were to pronate the limb with our hand, that would help to open up the space on the medial side of the elbow. Now in terms of your entry point for the arthroscope, it's done from the medial side.
I tend to like quite a kind of quadromedial approach, but you'll see in many of the textbooks to come a little bit more medial in, in this location. So as I mentioned, we can do this for both limbs at the same time, so we have both limbs draped and do one after the other sequentially. So let's see what this looks like in real time.
So what I would do is I would take a needle and syringe, insert that into the joint where I want my arthroscope to go, and then I draw back some joint fluid to confirm that I am in the joint. And then I'm going to inject some fluid. In order to dilate the joint, I then remove my needle and then in the exact same spot I then make a little stab incision through the the skin and subcutaneous tissues, but don't enter the joint.
And then I use the obduator and sheath to penetrate into the joint. Take the obduator out and can then insert the arthroscope into the sheaf. And then we're all set up, ready to go and look inside the joint.
And then we just insert a needle to act as an egress so that when we turn on our fluids, our fluids will go in through the sheath into the joint and then out of the needle and act as an egress, so we have a continuous flow of fluid throughout the joint. So this is what we may see if we were to look inside the joint. We're hoping to have nice white, healthy, smooth cartilage, which we largely have in this joint.
But then, oh, there is a radial incisor tip fragment with a little bit of cartilage we're adjacent to it. And then on the right hand side of your screen you can see that sort of red looking seaweed that is a synovitis. So this is then our fragment, we can see we're just given that little poke with a hypodermic needle and we can see that loose inside the joints.
So that's our fragmented coronoid process. So if we were to remove that fragment and a little margin of, of bone to perform a subtotal coronoid mastectomy, what I would do is first place in a hypodermic needle and line this up with the trajectory that I want my ostectomy to be at. Then we insert a scalpel blade, run it down the side of the needle, so you can see the tip coming in in the image on the left, and then the image on the right is the scalpel blade being advanced again at the trajectory that I want my osteotome to travel at.
So we then insert an osteotome, which is kind of like a chisel into the joint. And the image on the left shows that inside. The image on the right, I've then placed the osteotome deep within the bone, so I take a nice deep section.
I want to take a nice deep section, not just the superficial surface, because if we take a deeper section of bone, this means we can avoid the radius rubbing against the medial conoid process cos we're taking a deep section. If we just take away a superficial layer, then yes, we may reduce friction between the ulna and the humerus above, but we will still have some ongoing friction between the radius and the radial incisor portion of the medial crinoid process. So then we have a a mallet that can hit the osteotome, it travels through, takes away a little then tip of the medial crinoid process, and then we can remove that and the fragment.
So this again is another example, so you can see this loose fragment and and little tip of bone that we have removed. So once we've then kind of freed those up, we can then go in and remove them. And what you'll notice with that fragment is that the subchondral bone looks very yellow.
This is a very sclerotic abnormal bone, normal healthy bone should look a little bit more pink, because it would have some blood vessels supplying it. And then this is what we're left with afterwards, just these two incisions, and I'll just then seal these with a little bit of skin glue, just then means that no stitches need to be removed, and the glue just to help keep things sealed so you don't have any residual fluid sort of leaking out down the patient's leg and onto their bed. Now, as well as arthroscopy being able to perform procedures in the joint, it also allows us to assess to both form a diagnosis and also assess tissues that can help further planning.
So in order to assess cartilage, we have a scoring system known as the modified outer bridge score. This ranged from a normal being kind of a 0 to grade 5 being the worst. And effectively it's different layers of of cartilage where an exposure of the subchondral bone.
Now this is important from, I suppose, a prognosis point of view because the more cartilage that is lost, the worse the prognosis will be. And if we were talking about our stone in the shoe scenario and taking our fragment out of the joint, you take a stone out of your shoe, you will feel a lot better. But if that shoe has been rubbing on your foot, causing your skin to wear away, leaving you with a wound or a blister.
Then it means you're still gonna have a sore foot after you've taken the stone out of your shoe, and that's the same with canine elbows that if we remove a fragment but there is a lot of cartilage where an exposed bone, then I don't expect the lameness to go away completely. We may see some improvement, but the more severe the cartilage wear is, the less of a difference taking the fragment out has. So removing fragments is great when the cartilage is still healthy and we can see lameness resolve at that stage.
Inevitably over time, there can be some ongoing wear if the joint doesn't fit very well. But if you have a joint that has a lot of osteoarthritis, a lot of cartilage where taking the fragment out is less useful. Now another advantage of seeing the cartilage score is that we can use this as perhaps a guideline when planning additional surgical procedures.
So a way of thinking about kind of cartilage score, a grade one is when the cartilage is just a bit softer than normal. A grade 2 is when you have some superficial wear and it's sometimes described as being like a cobblestone appearance or the way that I'll sometimes describe it, it's like having snow and normal cartilage should be freshly laid smooth snow. But on the snow on the image on the left, there's been a little bit of rain, so you've got a little bit of dimpling in the surface.
So this would be out of bridge score 2. The central image shows a deep footprint in that snow where you can start to see some of the grass underneath. So you might start to see a little bit of bone underneath with these focal deep fibrillations in the cartilage.
This would be a grade 3. And then the image on the right we can see the grass exposed underneath where there is no snow, no cartilage, this would be grade 4. And then a grade 5 is when the bone is actually starting to, to wear away and become ebernated.
So medial coronoid disease ultimately can then progress to medial compartment disease, and this is a phrase we tend to use when we then have this progressive loss of cartilage within the joint. So if you lose the cartilage, we can then see the subchondral bone underneath and it's this kind of pinky yellow colour and the cartilage loss is always on the medial connoid process and the medial aspect of the humal condyle. And if there is further wear, it can extend over a greater region within the medial compartment.
And ultimately over time if the medial compartment starts to collapse, then you can start to get some wear on the radial head and then the lateral compartment can become affected. So medial compartment disease, unfortunately there is no cure, but there are some procedures that can be performed to try to reduce pain, reduce lameness, maybe preserve some cartilage if there is still some there. And there's different ways in which that can be done, which beyond the scope of of today's talk, but there are some algorithms proposed, .
This was the paper from Noel Fitzpatrick and ultimately we have kind of further modified things for for other procedures that we may consider. But the arthroscopic assessment of the joint can help us with planning. Now there is another arthroscopic procedure that is sometimes performed.
This is called a, a biceps ulnar release. And the idea behind this is that the, the biceps sort of brachialis tendon inserts on both the radius and on the ulnar. There's this big fan shape insertion on the ulna.
And the idea is that as this muscle contracts, it may pull the ulnar against the radius. And if we were rotating the ulna against the radius from the pull of this muscle, it might mean we get more focal pressure between the radius and the, the ulna. So a proposed procedure is to actually make a cut through this fan attachment in order to reduce the pull of the ulnar against the radius.
And that can either be done via an open or an arthroscopic approach. So what we would see inside the joint is the medial collateral that we want to protect and preserve, and then the biceps attachment is just adjacent to that. And then this image, this instrument, sorry, on the right is a push knife that can be used to push against the biceps tendon to cut it at its ulnar attachment.
Now another condition that kind of falls under the umbrella of elbow dysplasia is osteochondrosis. So this is failure of endochondral ossification. So it's where an area of subchondral bone remains as cartilage and doesn't turn into bone.
We then have a thick area of abnormal cartilage that can become loosen and fragment. So this is what we may see on a CT scan is we see this subchondral defect where there is not bone that's formed. There's often an area of sclerosis around it, and in the elbow joint it generally tends to occur on the medial aspect of the humeral condyle.
So this is just showing you a shoulder example, but it just shows you what we might find whereby we have this sort of flap of cartilage. This is what it would look like then if it was removed, and what we can be left with is a, a defect or kind of a pothole in the joint surface. So we can do some therapy and treatment of this arthroscopically.
So we can remove the fragment via arthroscopy. And for small OCD lesions that can cause a big improvement in the lameness. And we can take them out with the scope.
What you'll be left with then is, is some subchondral bone, and a potential procedure that may help is something called micropicking or microfracture. The idea of this is that you penetrate the subchondral bone to allow bleeding to come to the surface with the aim of bringing in. Cytokines and growth factors that can allow fibrocartilage to form and therefore we may be able to form a fibrocartilage scar.
So what this arthroscope image is showing you is a little bit of faint bleeding from the subchondral bone following a microfracture procedure whereby we're poking that that subchondral bone. Other ways which we can treat OCD tend to then be more open approaches. So if you had a larger defect, you may want to resurface.
That can be done with an ostochondral graft, where we take bone and cartilage from another joint or potentially a donor patient and insert that into the defect. Or we also have a synthetic version which is a plastic surface, this is the sinacar implant plastic surface and then it has a trabecular metal backing that allows bony ingrowth. So that's what this would look like on pre and post CT.
On the CT we can see the trabecular metal base, and then there will be a plastic component that sits in to form a mimic of cartilage. And this would be a radiograph and I've also combined this with an ulnar osteotomy with the aim of unloading the medial compartment to take pressure off the friction surface between the ulna and the sinicar implant. And now another condition that we can have occurring in the elbow that we can see arthroscopically.
Is incomplete ossification of the humeral condyle, or what we now more commonly call a humeral intracondylar fissure. The reason now we call this an intracondylar fissure is because we have seen dogs who do fully ossify their condyle and subsequently development a fissure later. So the CT examples on the left are sequential images.
So the top row of images show one CT, and then the images below show another CT scan done of the same elbow a number of months later. And what you can see is there's some increased sclerosis at the back of the joint and maybe just the very start of a faint fissure. But then over time we can see the sclerosis has extended across the condyle and the fissure is progressing.
So we see these are progressively forming. And if we were to look arthroscopically, we would be able to see that fissure in the cartilage. Now they always occur cordially, and the idea is that perhaps there's a mismatch in fit between the anineal process at the back of the joint and the humeral condyle and an isthmus, and therefore it's prising apart the condyle and causing these stress fissures and stress fractures to form.
The way in which we can then treat these is by placing a screw across that fissure in order to stabilise the bone. Because we have now increasing thought that these are due to incongruity of the joint and increased pressure of the anineal process against the back of the humerus, we'll sometimes consider performing an ulnar osteotomy in order to reduce that pressure in the joint. And there is now some more papers coming out, some work by Alan Danielsky, where he's taken that a step further, and in some patients performed an ulnar osteotomy without placing a screw across the condyle and on follow up CT has seen evidence that some of these humeral intracondylar fissures may actually heal.
If the pressure in the joint is alleviated from an ulnar osteotomy. So this is something that is kind of very new and therefore I think we need a bit more data on this, but this is something that's very interesting and and may ultimately change how we do end up managing this condition in some dogs. Now the problem with having a a hi is that they can cause lameness in their own right, but they can also then lead to fracture.
We can see different ways in which the condyle can fracture. And ultimately, ultimately we may then need surgery to repair these. Now another use of arthroscopy in the elbow that I quite like is if I am performing a fracture repair of a condyle, I can use an arthroscope to assess intra-articularly, how I got that condyle back together.
So this is our sort of set up in theatre, whereby we have an arthroscope and this particular example here is a nanoscope, so it's a very small needle scope and then we have this screen that we're able to to look at and then the image on the. Bottom left shows us inside the joint, so we can see the fracture running through, but we can see that we've opposed these surfaces back together nicely. So under arthroscopic guidance, we can reduce our fracture and then we can stabilise it with implants.
So the next joint that we will often use arthroscopy for is the shoulder joint. And a particular condition that we see very commonly in the shoulder, we've already touched on is our osteochondrosis. So again these sort of defects, these potholes in the in the cartilage and potentially these loose cartilaginous flaps.
So the humeral head is the most common location in dogs to see these lesions, and we can use arthroscopy in order to to diagnose and remove these cartilage flaps. So this was the example that I showed you earlier. And we also then have the option of resurfacing the humerus as well, with a, a sinnerar implant for large defects.
So let's run through some other shoulder conditions and where arthroscopy may be helpful. So we can see quite commonly, although sometimes it can be incidental, pathology to the supraspinatus. So we can see that it's insertion on the humerus.
We can have a tendinopathy, whereby the, the tendon of insertion gets sort of repetitively strained. These tend to be grade 2 strains, so it's tends to be rare to see the tendon completely tear. And what tends to happen over time is we start to have a lack of inflammation.
The body sort of starts to become inflamed and then sort of, and the tissue becomes inflamed whilst the body is then trying to heal, and then this tends to stop. So we tend to get this sort of tendinosis. And what happens is we get some scarring and that can mineralize.
So we may see on imaging some mineralization to the the supraspinatus. Now quite often this can seem to be an incidental finding and occurrence that I see it very commonly is patients who have elbow disease. So they have elbow dysplasia.
We pick up on CT scan this mineralization. My theory is that they're just overworking their shoulder muscles to compensate for their elbow, getting these repetitive strain injuries, and then getting some scarring. So just picking up some mineralization in the supraspinatus doesn't necessarily mean that's the cause of lameness and that specifically needs treatment.
So keep an open mind that there could be problems elsewhere. Now in terms of the location of this mineralization. CT can be helpful to see where it is because it may be quite cranial, as in the example on the left, or it could be quite medial as in this example on the right.
And if this minimization of the tendon is quite medial, in this yellow circle is where the biceps runs. So we could potentially have impingement of the biceps. And if we were to then look inside the joint, we can actually see bulging of the joint capsule from this supraspinatus mineralization.
So that's something that we can pick up arthroscopically. We can use ultrasound to assess as well whether or not the supraspinatus muscle and tendon is actually impinging on the biceps. So we can see this kind of bird's beak appearance of the supraspinatus, and then we can see the biceps adjacent, and we can see if there's any impingement.
For superspin pathology, we'll typically treat these conservatively, and perhaps with some PRP shock wave, laser and rehab. And there is some evidence to show that stem cells and PRP, so regenerative medicine can be helpful in terms of the healing of, of these tissues. So again, this is just showing the close proximity of the supraspinatus and the biceps.
And biceps pathology can quite frequently, rather than be primary, be secondary to the supraspinatus pathology. Now the biceps tendon of origin is something that we can see on arthroscopy very well and we can then see is that tissue damaged or inflamed or or potentially even torn. And we're able to see the, the biceps tendon move up and down within the bicipital groove of the humerus.
Something else that we may also have is these little new spurs of bone that can form within the. Biccipital groove of the humerus, and these can then rub on the biceps. Now whether these rubbing on the biceps cause bicipital teno synovitis, or whether bicialtenus synovitis is present, irritating the periosteum, causing these bone spurs to form, I think we're not quite entirely sure which is the, the chicken and the egg, but this is something that we may find.
So with arthroscopy of this shoulder, again I find it really useful to have an assistant who can help to stabilise and manoeuvre the limb whilst we are are looking inside. It can either be done with a standard arthroscope or as we kind of touched on earlier, you can also do this with a needle scope, with a needle scope you just end up with a very small, incision into the limbs, so very minimally invasive, and from a diagnostic perspective, we could do this with a relatively small clip, almost as if we were doing an arthrocentesis or a joint injection. And if we do have the, the, the arthroscope inside the joint, we can also use that as a way to administer any intra-articular medication.
We know it's gonna go into the joint, we can actually see it via the arthroscope going in. Another problem with the biceps tendon can actually be a rupture of the biceps. So this dog's right limb or the left image is the normal side, whereas the dog's left limb, which is to the right of your screen, is the abnormal side.
So what we shouldn't be able to do is to fully flex the shoulder and fully extend the elbow. So we have the limb going in a straight line like the image on the right, that is diagnostic of a of a biceps rupture. And we can see that then in, in this dog.
And actually the little image on the right is then needle arthroscopy of this dog, which actually shows the torn biceps tissue. So we can see those white sort of strands and fraying, that's fraying of the origin of the biceps tendon. Some other conditions of the shoulder we can use arthroscopy for can be useful to look at the medial structures in the shoulder.
So we find we can get strains to the subscapularis muscle and potentially sort of sprains to the medial gleny humeral ligament, and sometimes this has been coined medial shoulder syndrome, so we have pain on extension and abduction of the shoulder joint. Generally we tend to see this as a repetitive strain injury, it's the classical one from the textbook example would be your agility dog going in and out of the weaves, putting strain on the medial tissues of their shoulder. I've also seen a few heavy small breed dogs have er medial shoulder syndrome, and the reason for having this image of a a couch and a a smooth laminate floor is that this is what lots of people's living rooms look like nowadays.
And you find you maybe have these kind of small, stocky, angry dogs who whenever the doorbell rings, they jump off the sofa, land on the floor, turn sideways, slip and skid, and go racing to the door barking. And I think it's dogs doing this quite frequently can be a reason why they can get this medial shoulder syndrome condition. Now if there's no instability, and we typically manage this conservatively, again, things like PRP shockwave and then we may put dogs in some hobbles in order to prevent abduction whilst the tissue is healing.
If, however, we have a grade 3 injury, so a complete tear, and instability of the shoulder, this is then where a surgical repair would be indicated. So having medial shoulder instability, we'd have a marked increase in abduction angle. So this would be sort of the normal shoulder being abducted on the right, and then this is the abnormal one on the left, and we can see there is this increased difference.
And you can use a goniometer to measure and there were some studies that came out giving sort of various angles of measurements, but I wouldn't worry too much about the exact number that you get because what we've seen is there is a lot of variability between individual dogs. But what can be useful is to compare one limb to the other. Now the final joint I wanted to cover in today's webinar was the stifle joint.
Now the most common condition that we see affecting the stifle is cranial cruciate ligament disease, whereby we have this tearing and fraying of the ligament and then the instability leads to this cranial caudal movement of the tibia and femur relative to one another. So we have the ability with arthroscopy to go and and look inside the joint. Ooh, this was supposed to be a video showing you cranial tibial thrusts, but I'm sure you're all aware of what that looks like or cranial draw.
And when diagnosing cranial crucial ligament disease, we'll often use radiographs to help us. So it'll be a combination of our physical exam and radiographs initially. Things that we tend to see on radiographs are a increased effusion inside the joint.
We may also have some osteophytes and enthesophytes forming, so we tend to see enthesophytes perhaps at the insertion of the cranial cruciate ligament on the cranial aspect of the tibial plateau. We often have osteophytes around the femoral trochlea. And perhaps on the poles of the patella.
Now, what I wanted to show you in this particular image is you can actually see the cranial subluxation of the tibia relative to the femur. So on this image on the left, if we look at the point of the intertypicular eminence on the tibial plateau relative to the femoral condyle, it's roughly in the middle. Whereas if we look at the image on the right, we then look again at the centre of the plateau, but the centre of the condyle and we can see there is this offset whereby the tibia has been displaced in a cranial direction.
Now, on radiographs, we cannot see the cranial cruciate ligament. So in order to confirm our diagnosis before doing something like a surgery to help, it's important to look inside the joint. And that can either be done with an open arthrotomy or an arthroscopy.
So what the arthroscopic image on the right is showing you, it's it's just showing a a shaver just with the suction running and what you can see is the two ends of the torn cranial cruciate ligaments. So we've got one end at the top and one end down at the bottom. The other ligament running just behind is the caudal cruciate ligament.
Now the other structure that we want to look at in joints is the meniscus. An arthroscopy allows us to have a nice magnified view of the meniscus, and we can also use arthroscopic instruments to to probe the meniscus as well. Some advantages of arthroscopy is we can have a magnified illuminated image.
And some studies indicate that it increases the detection rate of meniscal tears over an open arthrotomy alone. So what we can see in this scope image is that our probe has gone into a tear in the meniscus and is able to pull that forward. And you can see some torn meniscal tissue, a little bit of that red synovitis just obscuring the view a little bit, and that'll be an example of a bucket handle tear.
So how do we perform arthroscopy of the stifle? Well, I'll show you this example, er, in this particular case I'm gonna use to say the needle arthroscope that I referred to before. So what I do similar to the elbow, is I take a needle and syringe.
You notice I place my fingers on the patella and on the tibial tuberosity, and I then go roughly halfway or maybe slightly proximal. And just to the medial side of the patella tendon. Once we have our needle confirmed inside the joint, because we've drawn out somenovial fluid, we can then distend the joint with fluid.
Once we start to have pressure, we then remove. Then what I tend to do is if you have a little bit of bleeding or a little bubble of fluid, I leave that there so you can see where to go with your scalpel. And then with our scalpel, we're gonna make a little incision into the skin.
I tend to drag the skin against the scalpel blade to widen it. And then we can take our. Obcurator and sheath, and then we can use those to penetrate inside the joint.
Let me have a little pop And then when we pull out, you just notice a little bit of fluid comes squirting out, that's the release of pressure from the distended joint. Another reason why I like to distend the joint is cos if you see that fluid come flushing out, you know that you are inside the joint with your sheath. Then we insert our needle scope.
And then er we can start to have a look around and if you didn't have a fluid pump to pump fluid through, you can just use a little syringe like I've attached here. We then place a needle on the lateral aspect of the patellar tendon into the joint. We have fluid coming out so we know that's inside, and then we can use a scalpel to run down and create an opening, so we run the scalpel down the needle and then we can insert an instrument such as a meniscal probe.
Now for me personally, I tend to prefer placing the arthroscope medialy as I find it allows me to look at the medial meniscus better, particularly back at the caudal horn, but some people will recommend doing the opposite and placing the arthroscope in laterally and having your instrument in medially. The advantage of that is by having an instrument medially, it's maybe easier to use that instrument to treat and probe the medial meniscus. So you can do what works best for you, or you can actually switch back and forth.
So you may elect to place the arthroscope in via a medial incision first of all, in order to allow a good assessment. Then you might switch the arthroscope over to the lateral side and then have an instrument come in immediately in order to do any meniscal treatment. So you might have a set of scissors come in, you might have a shaver come in, or you might have a punch come in in order to remove torn sections of meniscus.
And then once we then have our diagnosis, we can immediately then go ahead perhaps with surgery. So for me, 99% of the time in dogs tends to be a TPLO. The way I describe the TPLO to clients is I talk about the differences between the dog knee and the human knee.
So the radiograph on the left is a canine stifle, the radiograph on the right is a human knee, and the green line is the tibial plateau. And how I describe this in dogs is that we have this steep tibial plateau, but more of a flat surface in humans. And because in humans we have this flat surface, I describe that the femur can sit on top of a flat surface of the tibia and be quite stable.
And a lot of people who maybe aren't athletes can get away without surgery. The muscles just help balance everything on a flat surface. So the way I try to simplify it to clients is I say that we try to make the dog knee more like the human knee.
By taking the steep surface and making it flat like a human and therefore in most dogs we don't actually need to replace. The cranial crucial ligament itself. So I showed them this little video of this instability, the femur sliding down the hill.
You can then make a semicircular cut, rotate the tibia around, and then the femur will sit on top of a flat surface. And as I say, for me, I will typically tend to recommend a TPLO procedure. Again, there are other procedures that are available.
Generally the best procedure is the one that that individual surgeon is gonna feel most comfortable with and feel that they get good results with. So I hope you have enjoyed me pointing out some useful tips and tricks with arthroscopy, some indications of why we may use it. So how it can help us with our our diagnosis, and also how we can use arthroscopy to treat certain conditions.
If after watching this you do have any questions, then please feel free to reach out and get in touch. Either you can ping me an email or feel free to connect or follow on social media. I'd be happy to try and answer any questions that you have.
Thanks very much.