Hello and welcome to this webinar on salvage surgery in orthopaedics. In this webinar we'll be looking at what you can do when tissue can't be saved. I'm James, and I'll be your host for the next hour or so.
Just a little disclaimer as we start. Throughout this presentation, I'm gonna show you a range of implants from certain manufacturers, but these are just here for illustrative purposes, and other implants from other manufacturers are available and exist. And the fact that some particular manufacturers have been included or some have been not included is not a recommendation for them as an individual, er it's just purely for er illustrative purposes.
So, in terms of our learning objectives, main things we're gonna focus on our joint arthrodesis, joint replacement. We'll also then look at replacing focal areas either with implants such as an endoprosthesis or by transferring some parts of the body to others. And we'll also look at amputation as well as a completely viable option when tissue can't be saved and er give you some tips and tricks about amputation as well.
So as well as kind of going through those learning objectives, also just really wanted to make you aware of what is possible. We're now at a stage in veterinary orthopaedics where almost anything is possible. Not everything is yet perfect, and there's always gonna be improvements, but we're kind of at a stage of progress where if you can think of it, it can happen.
So what's important now is just because something is possible it doesn't mean it's the right thing to do. Now the complexities of every procedure kind of beyond the scope of this talk, but I just wanted to make you aware of some of the things that are possible because just like myself in the picture with an iPad, all clients now have access to the internet on their iPad, phone, laptop, and therefore they can be aware of what is possible. So it's useful if you're also aware too.
This then just reduces the chances of you getting caught out and maybe not offering an option because you didn't know it existed and then clients getting unhappy saying you didn't tell me I could do this as an option. So just want to make you aware of some things that are possible, and then it's a great idea to either do some more research or to speak to a specialist orthopaedic surgeon to learn some more of the the nuances of the procedures and whether they are things that could be recommended for your patients that you're seeing. So I guess you could kind of say that nature is the greatest architect.
Evolution has meant that our bodies and our canine and feline patients' bodies have been designed very specifically to the needs of what that body has to do, particularly from a locomotion perspective. So often our aim is to try to repair what's there or try to restore tissue back to its original condition. Now unfortunately sometimes pathology renders this not possible and therefore we have to look at alternatives.
So some alternatives would either be to replace tissue to try to replicate what the original structure was. So you might say this is like having a a torn ligament, and we put in a ligament from elsewhere in the body or an artificial ligament to try to replicate the original tissue. It might be that we adjust anatomy so that those original structures aren't needed.
I guess the the most common one in in veterinary orthopaedics is going to be the osteotomy procedures such as a TPLO for a patient that has ruptured their cranial cruciate ligament. We change the anatomy so that the cranial cruciate ligament is no longer needed. Or the other option is that we kind of remove the tissue altogether.
Now, in kind of mild scenarios of musculoskeletal pathology, it might be replaced, it might be possible to just replace a small part of anatomy, you know, such as a ligament, and really I suppose what we're gonna kind of cover in this presentation is more severe scenarios. So we're talking about tissue replacement, yes, we do that quite commonly with replacing or augmenting. Some ligaments and tendons, and parts of the body, but rather than just focusing on small areas, we're gonna look at more kind of, severe issues whereby larger aspects of anatomy are affected.
So if we're kind of referring to a joint salvage, we kind of have sort of three options for that joint or potentially even for that limb. We have the option of replacing tissue such as a joint replacement. We have the option of fusing tissue such as an arthrodesis of a joint, or we have the option of, of removing some of the tissue, either removing parts of the joint, such as a femoral head and neck ostectomy, or maybe removing the limb altogether.
Now, joint replacement would theoretically be the best option because it maintains more normal mobility of the limb whilst also removing potentially pain and discomfort from that joint. So if we were to kind of focus purely on the joint, that would be the best thing to do. But whenever I'm making recommendations of, of treatments for patients, I always then take a sort of a a zoomed out approach and I consider three things.
I consider what is maybe the best option for the joint and what are the other available options. I then think, well, what's gonna be the best for that individual dog? So for example, we could say joint replacement is maybe the best option for the joint, but if we zoom out and look at the dog, we see that this is an elderly patient with lots of comorbidities and actually putting them through a big surgery like a joint replacements maybe not in their best interest, and therefore perhaps joint replacement is not the best thing to do for that dog.
And we could also zoom out again and then say also for the family of that dog. So again, we might say for that particular joint, a replacement would be ideal, and maybe the dog is a good candidate for joint replacement, but maybe the family would be unable to provide the postoperative care needed for that dog. It may be that financially they wouldn't be in a, in a good situation to be able to pay for that type of treatment for that dog.
So there's lots of other things we also need to factor in before ploughing ahead with surgery. Now in terms of indications for a joint replacement, the, the main indication for most of our patients is gonna be osteoarthritis. That basically can't be managed conservatively.
So frequently we'll try a conservative approach first, maybe by adjusting exercise, rehabilitation, weight loss, medications, but if we're not getting a good outcome, then we would consider joint replacement. And there will be some situations where in some patients we will hold off joint replacement for longer and others where we might elect to jump in sooner. Now, in terms of dogs having osteoarthritis, normally there is an underlying cause.
And it's often a sort of deformity such as a, a dysplasia to the joint, so hip dysplasia would be kind of the, the most kind of common example. It might be that there has been a significant trauma to a joint that has meant that joint can't be successfully reconstructed and therefore should be replaced because of the articular trauma means that it's gonna be painful as those surfaces continue to move and that the patient is either going to develop severe osteoarthritis or maybe already has it. Might be that there's an instability because of some soft tissue trauma around the joint or soft tissue degradation and therefore the joint is painful and developing osteoarthritis.
And we can also have disease processes, either we can have certain, joints that can develop necrosis such as a leg calve perphase disease or femoral head and neck necrosis. We can have immune mediated disease and if we had neoplasia, very focal within a joint, we can also consider joint replacement for that as well. Now there are some prerequisites that we need to have for joint replacement to be successful.
So we need to have a vascular supply to and around and beyond the joint. So if there has been a severe trauma and the vascular supply has been affected, then we don't want to be going ahead with a replacement. We need to have nerve function for the the limb to still function correctly.
And we need to have a a decent amount of muscle support as well in order to allow the joint to move and also to maintain stability of the joint replacement. And speaking of stability, for most joint replacement implants, we also need stability of that joint. For example, we need things like the collateral ligaments to be intact.
So if we took, for example, a knee replacement, we generally need the medial and lateral collateral ligaments to be intact to provide stability to most knee replacements. Now it is possible to make custom joint replacements whereby they have a partially constrained hinge system. So this is something that we utilise for for knee replacements and in this situation, you actually don't need to have intact collateral ligaments.
But for most of the commercially available joint replacement systems, such as the knee replacement, elbow replacement and and ankle replacement systems, we generally need collateral ligaments to be intact to prevent luxation or collapse. And we also need sufficient bone stock. So in some cases of neoplasia, we need to be careful if we were to remove an area of bone in order to remove the tumour, would we have enough bone stock in order to still fit our implants?
And then as well as focusing on the patient, we need to then focus on everything else that will be involved with such a big surgery, such as the aftercare that's going to be required, the rehabilitation that's going to be required. And in veterinary surgery, joint replacement does tend to come at the higher end of of kind of costs, in part because of the implants and in part because of the. Special expertise needed in order to perform the surgery.
For many replacement procedures needs to be quite a big team approach, and then there's often quite a lot of aftercare involved as well. So, we need to make sure that everything is in order for surgery to go ahead. So the most common joint that's replaced in dogs and cats is a hip replacement.
These have generally now become quite routine, and often considered as gold standard. I know we're kind of moving away from, from that kind of phrase, but, often considered sort of gold standard. We can have very, very good outcomes.
However, the potential complications can be quite severe, so. We kind of really want these procedures done by people who are, or surgeons who are performing at a high number, and have learned some of the nuances of these procedures because the technique to insert many joint replacements is very different to some of the techniques used for other surgeries, in terms of things like reaming and broaching. We don't use these techniques for other surgeries, so it's a different set of skills, and therefore we do want to be careful who is performing such procedures, but we can have very good outcomes with, with hip replacement.
Knee replacement, again, can also get very good outcomes with this surgery. It's done much less frequently compared to hip replacement, probably in most part because it is less likely that dogs have such severe stifle disease that such a surgery is needed. Or those dogs that do have severe stifle disease also tend to have, for example, ligament pathology that makes them perhaps no longer a candidate for the commercially available knee replacement like this.
So in terms of joint replacement, there's often a metal implant on one surface and a plastic implant on the other surface with a low coefficient of friction that allow these implants to move smoothly against one another. Now there is also total elbow replacement. At the time of recording, I would probably say to you just pretend this doesn't exist because unfortunately, unlike hip and knee replacements, elbow replacement has a very high complication rate in dogs and therefore, although there are modifications and newer systems becoming available.
Generally, the complication rate is still very high. Hopefully we will see that change because there are so many dogs who could benefit from an effective elbow replacement system. Some of the reasons why the failure rate can be so high, is in part because the elbow is more complex, being three bones that come together.
And often the replacement systems try to convert, essentially 3 moving bones into 2 moving parts, and there's then a lot more, force and strain on, on these implants because of the way that the elbow would want to move. And you can see, for example, that there's this screw inserted here between the ulna and radius, and that's to try to limit the movement of those two bones as the radius and ulna supinate and pronate. There's a huge amount of torque and movement that would put strain on the implant.
And, additionally, the problem that we have is that the hip replacements and knee replacements in dogs are very similar to those in humans. So there's been decades and decades of research for human implants, and they were used in dogs as research models, and then we can take that information and basically put that back into dogs and use what's been learnt for humans to to help dogs again. But the challenge is, as humans, we don't walk on our elbows and the requirements of an elbow replacement for a human is very different to a dog, so we're kind of decades behind in terms of R&D for for elbow replacement in dogs.
So it's an option, but I would generally say to you try and do everything you can to avoid getting to that stage with your patients. Now something that's done very rarely but is possible is a total shoulder replacement, so we can replace the glenohumeral joint. Something else that's done infrequently, but we may see an increase now that there is a commercially available system in the veterinary market, is ankle replacement.
Now what we've looked at so far is kind of a full joint replacement. The other option is kind of partial joint replacement or just resurfacing of some smaller areas. So just gonna show you kind of a handful of possibilities.
So in regards to the elbow joint, we can resurface a focal area in the medial compartment of the elbow. So with developmental elbow disease, medial coronoid disease, medial compartment disease, it's always that medial side that has the problem first with cartilage where between the humerus on the medial side and the ulnar. So an option is to replace with a metal surface in the humerus, and then there is a plastic surface with a metal backing that fits into the ulnar.
So that will be what these, these implants look like. And what you'll see then in surgery is that we have these focal areas whereby we have this metal implant on the side of the humerus and the plastic implant on the side of the ulnar so that these sit ever so slightly proud so that they try to be the main contact areas when the limb is in a weight bearing position. But you can see they only resurface a small area of the joint.
And ultimately the inflammation in and around the joint and the synovium remains, so these procedures don't resolve osteoarthritis. Unlike a full joint replacement, these procedures are more aimed at at resurfacing a focal area. Another option very similar then if we have a cartilage defect is we can use an implant to resurface that area.
The most commonly used, option is, is the sort of sinacart implant in dogs. So here I'll show you through a, a, a kind of a case. So here we can see that the main reason we use this is for osteochondrosis lesion.
If we then took away that that flap of cartilage, we then end up with a pothole. And if that pothole is quite large, just like having a large pothole on your road, you would want the council to come and resurface that so we can resurface the joint as well. Instead of tarmac, we can use the sinicca implant.
So the way in which we would do that is we would have a cylinder guide that we place over the defect, and then down the centre of that we can drive a, a guide wire pin. Now what's really important with any resurfacing or joint replacement surgery is that we have everything aligned correctly. So you can see as I'm weaving my head around, I'm constantly looking to check that I've got this aligned correctly so that it is perpendicular to the joint surface.
And once that pin is in position, we can then place a reamer over the top, and this will then create kind of like an, an apple core, a cylindrical. A hole within the cartilage and subchondral bone. OK.
And then we have our implant er that has say our plastic surface on one side and then the trabecular honeycomb metal on the other side and that trabecular metal allows for osseous integration and boning growth. So we're just going to line that up in the hole. Insert it.
And then we just need to tap it into place. And that will allow us to then have a continuation of a smooth surface on the joint rather than a large defect. And this is what it would look like.
And the most common example, or most common place that the dogs get, OCD lesions is their shoulder, but they can also occur in the elbow joint on the medial humeral condyle surface, so we can resurface that area. Here we can see the pre and post-op CT images of the defect in the red circle and then the implant. With the implant we can see the metal, but we can't see that plastic piece, but you can imagine where that is.
Also, the stifle joint is a kind of another area where we can have OCD that we can resurface as well. So this particular patient has had a resurfacing, and has also undergone a TPLO procedure. Now other focal areas of joints that we can replace, one example would be the patella groove.
So we can have abnormal cartilage, wear and . Focal loss of cartilage over the femoral trochlear. We can also have malformation of the ridges in patients who have a limb malalignment and subsequently patella luxation.
And as that patella is perhaps not putting pressure in the trochlear groove, we can have a malformed trochlear form. And as the patella luxates back and forth over the ridges, it can weigh down the cartilage. So one option would be to resurface that.
This is an example of the implant from Cion. Again, there are others available, but this is then resurfacing one half of the femoral patella joint. In human patients, you may also have an implant put on the underside of your patella.
Given the patella is so small in in dogs and cats, generally we tend not to do that at this moment in time, but maybe things will change in the future. And it's it's also possible to resurface the tar ridge, so if we had an OCD lesion in the talus and then a malformation of that talus, we can, we can replace that. At the moment this is just done with kind of custom made implants and there's a couple of companies offering such implants in order to resurface the talar ridge.
Now, as well as replacing focal areas of joints, it's also possible to replace focal areas of bone. And that can be done with an an endoprosthesis. So these are sort of limb salvage surgeries whereby we frequently may consider amputation, but for these particular patients there may be an advantage to preserving their limb.
Now the aim of an endoprosthesis is to improve the quality of life and also improve function of that patient. They generally use where we have a severe localised musculoskeletal problem, and these are highly specialised surgeries and we need kind of careful case selection. So, at least for example, kind of, you know, cases perhaps that that we see at the practise is probably more cases where we say no, it's not an option than patients where it is an option, but it is something that that we can offer in the right circumstances.
So what are those circumstances? What are the indications of an endoprosthesis? Well, generally what we're looking at is kind of focal pathology to part of the skeleton, either to a particular bone or potentially to a particular joint, or maybe whereby the diseased bone is very close to a joint, we may then replace both areas.
So frequently we'd be looking, say at neoplasia. Now with regards to to neoplasia, there is obviously the challenge that unfortunately most neoplasia in bones in dogs is osteosarcoma, and most of those have a high metastatic rate. So we need to consider the kind of ethical implications of surgery and whether it's right to go ahead with surgery and chemotherapy.
Should that surgery be an amputation or should that surgery be an endoprosthesis, and we therefore need to think about again the individual bone, the individual dog, and the individual family. We may also consider endoprosthesis if there has been a severe trauma. So maybe there's been a trauma and there is now actually a large defect to an area of bone, or maybe that area of bone cannot be cannot be reconstructed and cannot heal.
It may be that there is a non-union, so perhaps there has been an area of bone that has been attempted to heal and that has failed, and it might be deemed that if there is perhaps a large defect that may be replacing that with a metal implant would be a better option. So generally, we are looking at scenarios where there's a defect in the bone and we're going to replace that with an implant. Now in regards to neoplasia, that's probably the most common reason for endoprosthesis being performed.
There is gonna be a concern about local reoccurrence if the neoplastic tissue does. Spread and extend into some of the surrounding soft tissue. So that is something that we'd need to carefully evaluate.
If it looks like that there is spread of disease into surrounding tissues, then an endoprosthesis would not be indicated because there would be an extremely high likelihood of local reoccurrence. So if we, for example, look at this example, this is then a distal radial tumour. You can see the image on the left.
And what you can see again is this is picked up quite early, it's quite focal, it's quite contained within the bone, and therefore could be a candidate for an endoprosthesis. So the endoprosthesis that's been performed has effectively removed that section of bones. We've taken out this distal section of the radius and replaced that with a metal implant that's then secured to the radius, the ulnar, and down onto the metacarpal bones.
And given the proximity of this. Neoplastic lesion to the carpal joint, part of the carpal joint has also been removed, and this is effectively fused the carpus. Now again, distal radius is a very common place for dogs to get a tumour.
So this kind of distal radius ulnar endoprosthesis is probably the most commonly, performed. We can also, however, perform endoprosthesis in just about any bones, so this would be an example of a patient with a distal tibia lesion. That's been replaced and again converted to a panarsal arthrodesis with an endoprosthesis implant.
This is an example of a dog that had a, hip neoplastic lesion, and in order to obtain a margin, an endoprosthesis to replace half of the pelvis and also replace the approximal portion of the femur was developed. So we then had effectively a hip replacement with these large endoprosthesis implants and they're kind of created in a way to allow tissue on growth so we could have the tendons of the gluteal muscle attach and grow onto the artificial greater tracanter that was created. And we can also have endoprosthesis that are solely within the centre of long bones, so examples here showing a mid diaphyseal femoral endoprosthesis and also a mandibular endoprosthesis.
So it doesn't just have to be at joints or the very ends of bones, it can be for defects in the centre as well. And we can also use a prosthesis whereby we have an amputation performed but we want to link to the skeleton. So in these patients, Oscar the black cat is probably the most famous one.
We can remove part of the distal aspect of the limb, and then we can anchor an implant to the bone. And have a specialised part of the implant that allows the skin to grow onto it and form a seal, little bit like a deer's antler coming through the skin on their head, and that seal means that bacteria then cannot enter. So this is again an example whereby these are.
Implants that go through the skin, they're percutaneous, anchored onto the skeleton. Piece of the implant comes out, and that allows you to attach then an exoprosthesis onto this. Now the other option for a partial limb amputation is to use a stump socket prosthesis.
So this is something that is not anchored to the skeleton, it's just something that fits over the skin. So for, for most, if you think about most human people who have had an amputation performed, this is probably what they have a stump socket prosthesis. Now in terms of using these in dogs.
Nearly all cases will end up getting skin sores of some sort. So these are not straightforward insomuch as it's not you create it, you pop it on, and the dog goes off and, you know, lives happily ever after. You will see these patients back with with skin sores that we need managing.
So these need to have a lot of, of counselling to the, the, the clients in order to kind of prepare them for this, to know that these can be very helpful to their dogs. But they do require a lot of maintenance and work. And therefore, if the patient can manage on 3 limbs, it may be better to opt for a full limb amputation rather than trying to manage a stump socket prosthesis.
And with these stump socket prosthesis, they will need replacing, so they will wear out and also the, the limb will change over time because of changes in in muscle mass. And you will get some atrophy around the stump, so the stump will become sort of smaller and therefore the, the stump socket prosthesis may need to be modified over time. So, again, these can be a lot of time, effort and and finances involved in order to manage these.
But they can be a nice option for some individual patients. Now rather than using something artificial to replace part of the body, there are some scenarios where we can transfer the body's own tissue from one area to another. So probably the most common one that you might think of might be a skin graft, whereby if you have a defect of skin in one area, we can take skin from another part of the body and transfer that.
Another example that's used a lot would be sort of tendon grafts. So, less so in kind of canine and feline patients, more so I guess in humans, if, if you rupture your ACL, you might have a tendon from your hamstrings taken and placed in to recreate your, your ACL. But we can also transfer areas of bone and cartilage.
So these are some of the examples that I kind of wanted to show you whilst we're focusing on orthopaedics. So one option would be to transfer bone from one area of the body to another. So we talked a little bit about distal radius tumours and removing that tumour and filling it with an endoprosthesis, so filling it with a metal implant.
The other option is to transfer bone from one part of the body to another. So what the image on the right hand side shows you, and this is taken from the the the bottom paper, and what's been done is a distal radius tumour has been removed. And then the adjacent section of ulnar has been freed, moved across into the defect that was the distal radius and plated in position.
So what we can see is that this sliver of bone in here, this is actually the ulnar that's been moved from this position, transferred across so that weight and load can be transferred down through the radius down to the the carpus and metacarpal bones as most of the weight is transferred through the radius. What this image on the left shows is to do something slightly different, whereby what they've done is taken away the distal radius and then what they've done is moved the carpus and attached it to the distal ulna. So rather than say transferring the ulnar bone into the radial defect, they've transferred everything below the the manus carpus and transferred that across to the ulnar in order to create a continuation of of weight bearing through that area.
Something else that we can do is transfer areas of cartilage. So this is the sort of oat system whereby we have effectively these kind of Apple core type devices that can be used to core out a cylinder of cartilage and subchondral bone. And then that can be inserted into for example an OCD defect to fill that defect and resurface.
And then the bone and cartilage would would reintegrate. Now this is quite a a a cool thing and works quite nice in so much as I mentioned at the start that, you know, nature being that the best architect, you wanna try to create things as like for like as possible. The challenge, however, with this type of procedure is it means going into a healthy joint and taking some cartilage to transfer to the abnormal joint.
So by going into a healthy joint, you're gonna cause some damage to that joint. In order to minimise the damage, we kinda wanna pick an area of cartilage that is perhaps non-weight bearing, so there's not another surface of cartilage rubbing against it. And the place that's typically used then in the canine body is the medial or lateral aspect of the femur whereby we have no contact areas or no opposing cartilage contact areas for the surface.
Now the problem is that most of these areas tend to be more of a concave area, whereas the joint surface that we want to resurface, such as the humeral head tends to be convex. We tend to end up with kind of not a perfect match. Also, most OCD lesions tend to be more oval, so where you See in this example on the right with the yellow is that you can see there's one circular cylinder and then there's kind of another sort of half moon cylinder shape that's been used to try to fill this oval.
So it's never kind of a perfect match. And because that we're gonna have to cause some morbidity to the normal joint nowadays we tend to use the synthetic implants instead to avoid that. Now, sometimes it may be not possible or not advantageous to replace a joint.
And therefore we may want to fuse a joint. So that's what an arthrodesis is, it's kind of the surgical immobilisation of a joint by fusing bones together. Now the indications for arthrodesis are when the the benefits of the pain relief from the arthrodesis and the improvements in function sort of outweigh the loss of joint mobility.
So, the joints that are best arthrodes tend to be ones whereby either there is less movement or ones that are more distal in the body. Now if we were looking to perform an arthrodesis, there are some key principles that we need to be aware of. First of all, we need some careful planning.
I guess that goes for any surgery really, but it's something that we do need to be conscious of when fusing the, the joint. Then once we are in surgery, we need to remove all of the cartilage from the joint surface. By removing the cartilage, this then allows us to have bone and bone, and when we put bone and bone together, there is then the ability for this bone to heal and fuse.
Just like putting two ends of a fracture back together, they can fuse. Now cartilage is designed to stop joints from fusing and allow them to move smoothly, so we need to make sure we remove that cartilage. So if you are performing arthrodesis, I'd recommend being quite aggressive when you're removing the, the cartilage.
Make sure you don't leave any behind. We then want to oppose these bone surfaces back together nice and closely so that they can fuse, and we want to have rigid fixation, ideally using compression. Now there are things that we can do to try to encourage bone healing.
One of those is using a bone graft, so we can use Cus bone graft. Autograph tends to be the best or we can also consider allograft as well. And we also want to make sure we preserve the soft tissue, so we need to be careful to preserve the vascular supply, we also need to be careful to preserve the nerve supply passing past the joint that we're releasing down further to the distal extremities of the limb.
Now with regards to our careful planning, we need to think about what angle are we going to set the joint app. And joints are fused at the standing angle. And these are reported and described.
You can find these in, in your textbooks. But what I would kind of recommend you do is again treat every patient as an individual. It's not kind of a one size fits all.
I think we need to be kind of patient specific and tailor it to that individual if we want to maximise our results. So what I'd recommend doing is paying careful consideration to how that dog stands because different breeds of dogs have different confirmation. And also individual dogs within that breed will have different conformations.
So a good example would be to look at the opposite limb if that is normal, and look at the angle of that limb, maybe take some measurements, and then maybe tweak your surgery either within or slightly outside of these reference ranges if that better matches that individual dog. So for example, for the pancarpal arthrodesis, we're often setting an angle, kind of just over 10 degrees. But in some dogs you'll see that's gonna be too upright and some dogs do have a greater degree of extension.
And therefore, there is this balance. I would often try to match things closer to the opposite limb, or what the normal limb should be for that dog, but we sometimes need to be careful that we're not over manipulating and over bending implants cos it can weaken them. So there is always kind of pros and cons, and this is where careful planning does come into consideration.
So I mentioned that it's the joints more distal are the ones that are more commonly after a deed, so a very common one is the carpus. Some indications for why a carpus may be fused. We could have some arthritis, such as osteoarthritis or immune mediated arthritis affecting a joint causing pain, inflammation, and potentially some destruction to the joint.
It may be that we have a fracture to part of the joint. So these are showing some of the configurations of accessory bone fractures. And if we were to have a fracture, we can then end up with instability and we could end up with a Palmer grade stances like in this dog.
And in this situation, pancarpal arthrodesis can be indicated. Now in some dogs, we can also get degeneration of the supporting structure, supporting structures to the joint that can lead to to joint collapse. So in this sort of collie breed in the top example, you can see this patient has got this paler grade stands to their right limb.
But you also notice just behind that the left limb is also in a bandage, and that's because that bandage is helping immediately support a post arthrodesis, and we can see a little fentanyl patch here as well for the dog to keep them comfortable. They've just had surgery for their left carpus cos they've had degeneration of both carpi. So we see this degeneration type condition more commonly in in collie breeds.
Or in this patient, we can see there's been this complete subluxation or luxation of the carpal joint, significant trauma. Trying to reconstruct the ligament support to the carpus is extremely challenging. A lot of the support is from a palmar fibrocartilage that can be extremely difficult, if not most of the time actually impossible to repair.
And if that tissue does become damaged, then a pancarpal arthrodesis would definitely be indicated. Now instead of a pan, oh, actually, here's an example, sorry, of a pancarpal arthrodesis. So we have our carpus fuse with a plate spanning across the carpal joint.
In order to hold everything in rigid fixation. Most commonly, a dorsal approach is used. Some surgeons may use a medial approach, some may use a paler approach, but I would probably say 99% of the time for a pancarpal arthrodesis, it's gonna be a dorsal approach just like in these examples.
And that can either be done with kind of a an open approach where we open everything up, or we can do it via a less invasive approach whereby we make some smaller incisions through the skin and tunnel the plate through. For me, for, for pancarpal and pantarsal arthrodesis, I, I much prefer doing these sort of mepo type approaches. What I find is by keeping some sections of skin intact, I tend to find I have much less problems with swelling of the limb, much fewer problems with closure, and also less, chances of getting more concerns with infection or incision sort of breakdown.
Can be a little bit more of a, a challenge initially to do this, so again, starting off with an open approach would be the way to do this, but if you are getting a little bit more experienced, maybe consider these less invasive approaches wherever possible. Now instead of doing a full arthrodesis of the whole carpus, we can sometimes consider a partial carpal arthrodesis. Now most of the movement at the carpus is at the radiocarpal joint, but there are the smaller joints below.
And if those smaller joints, such as the the carpal metacarpal joints were affected, then you could just use those and preserve the radiocarpal joint. So in this example, this radiocarpal joint at the top is spared and this could still move. This would mean that the dog would still have a very good range of movement in that carpus and therefore would have generally a better function.
The problem and the challenge is that scenarios whereby just these more distal joints are affected are much fewer. And also sometimes it can appear that just those joints are affected, but actually the tissues supporting the radiocarpal joint are also affected. So we can sometimes get caught out and just perform a partial, but you then find actually more disruption to the joint has occurred, and this is why I can only actually here show you an example of a textbook sort of schematic drawing.
I actually haven't performed a partial carpal arthrodesis myself. Just say this is how dimly infrequent it is that we have this kind of scenario. Now the equivalent of the, the pancarpal arthrodesis for the pelvic limb would be the pantarsal arthrodesis.
So again, here we are fusing everything. Either of these can be done with a, a dorsal plate, which is, is my preference, or some surgeons will perform them with a medial plate. And occasionally in some patients they may even need plates orthogonally placed.
And this is then where kind of careful planning is required. There's kind of pros and cons of both a dorsal plate and a medial plate. And dogs can function very well with a pantarsal arthrodesis.
Again, these are frequently either performed because of pathology affecting the joint, such as osteoarthritis, maybe because there has been some severe trauma to the collateral ligaments, and we feel it's unlikely they would sufficiently heal, or also if there is collapse and a plantar stance. So if the common calcineal tendon has been ruptured. Then if you didn't want to go with trying to reconstruct or repair that tendon, you could consider a pantarsal arthrodesis as an alternative approach.
Now there is also the option of doing a partial tarsal arthrodesis we tend to find that the. Indications for this are much more common than with the partial carpal arthrodesis. So we can find dogs having isolated pathology or trauma through the tarsal metatarsal or the inter-tarsal joints and therefore we can just fuse those joints and preserve the radiocarpal joint.
And by preserving the radiocarpal joint, we will maintain most of the range of movement through the tarsus. So we'll have a much more normal gaiter and much less compensation from other areas of the body by preserving the tarsororal joint. Now all these examples so far I've kind of showed you plates and screws.
That's what is gonna be used probably 99% of the time. It's possible to do an arthrodesis with an external skeletal fixitter. But generally I would recommend trying to use the internal implants if possible.
This is much less hassle than trying to maintain an ESF and trying to achieve rigid stability with an ESF can also be harder and technically more demanding. So most of the time it will be with plates and screws, but in some patients we may consider an ESF, particularly in situations where we don't want to have an implant inside because of risk of infection. So if we did have large skin and tissue defects and and open fractures, then we may consider using an ESF.
Now, say the carpus and tarsus are the most commonly arthrodes joints in veterinary patients, but we can arthrodes other joints as well. Dogs can function very well with a shoulder arthrodesis because around about a third of the movement from the shoulder region comes from between the movement between the scapula and the thorax. So by after reducing the shoulder we will lose the movement at the glenohumeral joint, but dogs can still function very well.
Now, shoulder arthrodesis is not indicated that often. Most dogs who develop shoulder osteoarthritis can be managed conservatively. And therefore in most situations, at least for myself to perform shoulder arthrodesis tend to be when there is a deformity to the shoulder.
So in this patient, there is a defect mostly affecting the, the glenoid and therefore we've opted for an arthrodesis. As well as shoulder arthrodesis, you can perform elbow arthrodesis. Now again in terms of arthrodesis of the elbow, patients can have.
Some limitations to their mobility afterwards. They're solely really relying on their shoulder and a little bit their carpus in order to move their limb and therefore they tend to have a very stiff limb. That's kind of a bit like a peg leg in a way is a way you kind of describe it.
They're very sort of stilted gait. They can use this to walk on and, and sort of can kind of trot, but kind of doing lots of kind of running and jumping is gonna be very, very challenging. They have to circumduct their limb a lot in order to move, so the mobility is not brilliant, but it can be a way of removing pain from that elbow joint.
Not done very often, and again something to really strongly consider whether or not to proceed with it. So again, if you had a patient with osteoarthritis, I would kind of exhaust medical management first before jumping into an elbow arthrodesis. Earthrodes probably more likely to be utilised if there has been a failure in a previous surgery, such as if there had been a a humeral condyle fracture and repair of that has not gone well and it has failed, then maybe that we're opting for, for an arthrodesis.
Also possible to do stifle arthrodesis. Again, indications are not that common. Most patients who have osteoarthritis of their stifle can be managed medically and conservatively.
And again, the the function with a liarises is is kind of variable, just like this dog shows, they're gonna have a more sort of stilted gait, they're gonna circumduct a lot. But you might actually be surprised as to actually how well they can walk with with such a joint arthrodes, . But again, these are really sort of last resort, salvage type surgeries whereby we need to consider a lot the the pros and cons and and the risks involved in fusing such a joint.
You can also do digit arthrodesis, again, . Not done that frequently, in part we're gonna have lots of small bones and small implants, and very thin soft tissue coverage, so, so risks of infection and risks of failure for digs to fuse, risk of implants breaking, often need to be protected with with a bandage or a cast, and as you all know, they can cause us quite a large headache because of the complications that can arise and the frequent changes that are needed. This is the example of using plates and screws.
We can also perform this with an external fixitter, a technique sometimes referred to as pauses or pedal arch wire scaffold, whereby an external fixator is applied in order to pin the digits into position. Then the frame is connected to bars that anchor into the radius as well, and we have these rings on the bottom, and the dog actually walks on the frame so that digits are suspended in the ear in order to take the weight off them. Now, the one joint that we would not arthrodes is the hip joint.
So if we had a hip joint that we needed to salvage, we'd either be looking at a hip replacement or we'd be looking at something like a femoral head and neck excision. So a femoral head and neck excision's kind of like a focal amputation of a a joint of an area. So again, the, the hip is the most commonly joint where such a surgery is done.
It's also described for the shoulder joint whereby you can er do a glenoid . A glenoid excision, so you just take away the glenoid. Effectively it's kind of like doing a a femoral head neck excision for the front neck.
The results of that surgery can be a bit variable, and nowadays probably most surgeons would opt for an arthrodesis instead because you get a much more predictable outcome. We can also do excision arthroplasty for digits, so some of the interdigit joints, you can just remove part of the joint and then you just have the the soft tissues holding the the bones together. So on the topic of doing sort of focaler tissue removal from joints, we can also do larger tissue removal in the way of amputation.
So if salvage surgery, such as a replacement or an arthrodesis can't be performed, or it's not right to be performed, then we can consider amputation. And although a lot of this talk is so far focused on ways of perhaps avoiding amputation and salvaging limbs, amputation amputation can be a very, very good option for the majority of dogs and cats and the families who look after them, so. So this is a situation where actually for some patients amputation is gonna be the better route and it's not a case of trying to avoid amputation at all costs.
So the reasons why we might perform an amputation are also many of the reasons why we might consider a limb salvage surgery or a joint replacement surgery or an arthrodesis surgery. So let's perhaps have a little look at these in a little bit more detail. So neoplasia, something that we touched on either perhaps if we have neoplasia in a bone or in the soft tissues.
And we may want to Remove tissue in order to obtain a margin. So for this particular example. We can see this large tumour coming out the back of the stifle invading into the caudal musculature.
Now if we were to perform, say, an endoprosthesis and replace the distal femur and replace the proximal tibia with a custom made knee replacement, you could see that we would not remove all of the tissue in the back of the. Musculature, even if we try to resect that, it's very likely we wouldn't be able to get all of the microscopic disease away because we wouldn't be able to remove the neurovascular structures that are running down the back of the knee. So in order to obtain a margin of tissue around this to get rid of all of the local disease, then we really need to be looking at amputation as as the only viable option.
Another reason why we might want to consider amputation for neoplasia is because bone tumours in particular are very, very painful, and by removing that bone tumour, we can improve patient comfort. So amputation can be indicated from an analgesia perspective. Now it might be that you wanna consider amputation if there is severe trauma to to bones or joints.
Either because you deem perhaps it is not gonna be able to get a successful outcome by treating the, the traumatic condition or traumatic injuries. It might be perhaps that doing such a repair is cost prohibitive for the owners to treat and therefore we want to look for an option er that is within their financial limits. And if you did read through some of the reasons to perform amputation on the earlier slide, I mentioned factors such as kind of costs after care and prognosis.
And it's often sometimes kind of ethical factors that are also driving forces as to why an amputation is or isn't performed. So it might be that perhaps there would be an incredibly long recovery to manage a particular injury. Let's just say there are very large soft tissue wounds whereby there's large skin defects and therefore this patient would need to be hospitalised for for weeks.
It might take months for these areas to heal and therefore it might be deemed that an amputation would be a quicker option of getting patients comfortable again, back to their. More normal life, just by doing, an amputation we have a much, much quicker recovery time frame from. But all of these fractures, you know, could be repaired, and therefore you, you know, you can't leave them with a, a broken limbs, so it's either gonna be a case of repair or amputation.
And say. I, as an orthopaedic surgeon would, would love to kind of repair these fractures, but sometimes, er for some situations it may be better to, to perform an amputation. Now with lots of the things that we have covered so far, there's a lot of kind of ethics kind of behind it, and I suppose on the topic of ethics, a little bit of advice that was kind of given to me and I use this kind of in in all my consultations and I'd recommend it to you is to basically offer all clients all the options all of the time.
And what I mean by that is try not to judge people. It might look from a client's appearance or maybe the way that they speak that perhaps they are not financially well off, and therefore you might presume they can't afford to perhaps repair a fracture or afford to have a joint replacement done. And you might then opt maybe not to really mention it to them or or not to offer it cos you might feel bad about saying, you know, oh you, you could do this but you know they can't afford it.
And people feel obviously . Upset and sad in in that situation, so you might feel like you don't want to bring it up, but I would recommend that you do offer all the options because you can be surprised. Some people may have some insurance that can cover the costs, or it might be that people have saved away their money in order to, to cover the cost of things like these for their pets.
And they may look as if they don't have the money cos they haven't spent it perhaps on on things like their appearance, but they do have it saved away in order to provide medical cover for for their cats and dogs. And you'll also have the opposite situation. You'll have some people who look like they can afford things.
They'll they'll rock up in their their Range Rover and their tailored suit, but they'll opt not to spend a penny on on their dogs and cats. So don't judge your client's offer, all clients, all the options all the time. Cause what you don't want to do is to amputate a limb.
And then have the client phone you up a few weeks later, very angry, saying that their friend's dog had exactly the same problem, and they had their legs saved, and why didn't you offer the option to your client? Cause they may have chosen that rather than amputation. So back to some reasons why we may consider amputation.
We could have a peripheral nerve injury such as this cat had a brachial plexus injury and the radial nerve has not recovered. So we can see the limb is not extended, but it is held constantly up in this flex position. So it would probably be easier for this cat to manoeuvre around without having to carry this, this limb.
So we could consider an amputation. There's also some patients then who, if they have a nerve injury might . Not place their limb correctly on the ground and therefore drag their limb on the floor or they may drag their tail and therefore could be causing wounds and sores to form.
It may be that we could end up having urine or faeces scalding perhaps on a a tail and and therefore amputating that would be ideal. It may be that in some patients they can have an abnormal nerve sensation to their limb and therefore they tend to gnaw at it. And I've come across dogs who've actually, you know, sort of eaten part of their, their foot because it's felt so abnormal, they've been gnawing at it.
So in those situations we may want to consider an amputation if we have found either that the chances of healing are extremely unlikely, or we have given the patients a amount of time and not seen any improvement, meaning that functional recovery is unlikely. We may consider amputation because of a vascular necrosis, that could occur perhaps from a a thromboembolism. Maybe from an infection or unfortunately one of the more common reasons we tend to see is because of us placing perhaps a bandage incorrectly and it acts like a tourniquet and you could then end up with necrosis.
So pay attention to your bandaging tutorials and lessons and make sure you're very careful applying your bandages in order to avoid such complications. They consider amputation if there is a severe arthrosis, and if. Replacement or arthrodesis is not an option.
We may then amputate. Or maybe we have a deformity to a limb, such as this ectodactyle case, we may elect to amputate if the limb is not functional. So, we've looked now at some reasons why we may consider an amputation.
Here perhaps are a few little tips for you for when that patient is in your consulting room. So you've identified the problem, why you want to amputate, but there's a few other things we should look at as part of our examination. So you wanna kind of do a a full physical examination to assess the whole patient.
This is the same as if we're thinking about any kind of big sort of surgery. Part of the reasons for this can be because of anaesthetic considerations, amputations and, and joint replacements, and asphrodesis can be potentially, long procedures requiring a long anaesthetic. So we want to see, are there any underlying comorbidities that may affect the anaesthetic protocol.
You may even want to start treatment for such a condition first and then delay any surgery for the limb if it's not urgently required. I would also recommend paying, careful consideration to the other limbs, because if you're going to amputate, you're going to put more force onto the remaining 3. So perform a thorough orthopaedic and neurological examination of those limbs to try to understand how the patient will cope.
Now what's been shown is that the largest average increase in weight bearing is going to go on the contralateral for limb. And this is true if you amputate a pelvic limb or a thoracic limb. It's generally the thoracic limb on the opposite side to the limb you amputate is the one that is gonna have to take most of the increase in force.
So that's the one perhaps to pay most attention to. And you may even want to consider taking radiographs of the other limbs to screen for any underlying pathology. With regards to imaging, if we're doing an amputation because of a tumour, we may want to do staging, I would recommend you do staging in order to see is there any spread either to the draining lymph nodes or any distant metastatic disease.
Again, if we have a patient who has been in a trauma, don't focus solely on the limb that we can see that has the problem. We also want to assess the patient as a whole and look for evidence of injuries elsewhere, such as this feline patient who's had a diaphragmatic hernia and half of the abdominal contents are in the thorax. Also recommend having a thorough look again at the other limbs in patients who have had a trauma.
So actually I'd recommend this for any patient you have, that's been in a trauma, and this is something that I try and teach the, the residents and interns at the practise, is if you have a patient who's come in. And they're stable enough that you could get them to stand up, stand them up and see how they stand and function on the other three limbs. What I have seen happen before is patients who get brought in, they're sort of carried into the practise by, by the clients, put on a table, carried from one table to another and never really put down on on the the the floor or made to stand up.
And it's therefore been missed that they can't stand up on another limb, rather than just the really obvious one that has the trauma. And then they end up going through through surgery, having a, a, a limb, say, a fracture repaired, and then suddenly in the postoperative period you realise they still can't get up and walk because they actually have a, a soft tissue injury to another limb. So, or perhaps there's a a a nerve deficit to another limb.
So a way of kind of checking for that is if the patient is stable enough, just try standing them up with a little bit of assistance and see can they stand on their three other limbs. Now if we are going ahead with an amputation, er it's kind of really important to prepare the client so they know what to expect. And that their expectations are accurate.
Most clients will be really worried about how their pet will look and also how easy they'll be able to walk around on three legs. Now a study from a few years ago now revealed that around about 86% of clients were happy with the decision that they made in order to go ahead with an amputation and would choose the same option again. So, this is quite reassuring that clients are generally happy with their decisions, so this is something you can let people know.
I'd also recommend, having some photos as examples, maybe some videos of how dogs do get around on three legs and and what they would look like so that clients can kind of prepare themselves. Many clients will say my dog wouldn't cope on on three legs. But they actually come along from their car, walk into the practise, walk into your consulting room on three legs because they're holding up the leg that has the problem.
So you can already see that they would be able to get around and move on three legs, and you can actually then point this out to them at times. So that's something to, to assess for. And dogs who have had perhaps a chronic problem affecting their limb that's progressively got worse over time will have had more time to adapt to being on three legs, and often then these patients will.
Cope quite quickly and probably can, you know, go home a few days after their, their surgery, their amputation and already be functioning very well. Whereas patients who were used to being on 4 limbs and had no underlying problems and then perhaps have sustained a large trauma and had to have an amputation done quite quickly, they might be ones who need a bit more time to adapt to being on, on three legs. So the aftercare, it's good to kind of run through that with the clients.
You're really gonna have kind of 23 weeks to get those skin incisions healed and it might be that initially they need a little bit of help with a harness or a sling, and it's gonna start with some very slow, short walks and and gradually increase as patients build up their strength on their remaining 3 limbs. Something that I recommend that you do, er, and I actually recommend this for for every surgery or every orthopaedic consultation. I make sure you confirm the correct limb.
Make sure you're all on the same page as to which limb you're all talking about, because some people get confused between right and left, they sort of start to think, is it my right as I look at the dog, or is it actually their right? And there can be this kind of confusion. So what I do is I actually get up and I, I touch the leg and confirm, is it this one that that we're that you're talking about.
And then for the amputation, I'll get them to double sign the consent form. I'll get them to sign next to where it's stated the, is it the right or left limb that we're amputating and also then sign the consent form as normal regarding the complications, etc. Involved.
When you're preparing your patient for an amputation, I recommend doing a really wide clip of the fur, clip a really huge area, to make sure that you don't have any fur coming in and give yourself plenty of, of skin to manipulate and move. You can actually wrap a bandage around the distal part of the limb to save you time clipping all of the fur off everything distally. Doing a a hanging limb prep where the limb is hung up and then you kind of four quarter drape around is then very helpful.
And I'd really recommend having an assistant to help you during an amputation to hold the limb in certain positions for you whilst you're doing the surgery. With regards to our limb amputation, we can either do a, a full limb amputation, or you can also consider kind of a, a partial proximal amputation. So I, I, I tend to recommend doing a full limb amputation, and for the forelimb I'd also recommend removing the scapula.
The reason for doing this is by removing the full immb you don't end up with a stump and therefore you don't have any sores perhaps from that stump if patients were to lie on, on the stump, cos what will happen over time is the muscle will reduce around it. And you can then get sort of bony prominences under the skin. And the advantage, however, of doing perhaps a more distal amputation through the proximal humerus or through the proximal femur, is that it becomes a little bit easier with regards to ligating blood vessels.
So the more distal you go down the limb, the the smaller the vessels become, and therefore perhaps it's a little bit less scary, maybe a little bit easier to ensure that your ligatures are, are securely placed. So there are some advantages for surgeons, but I think for the patient it's generally better if you do a full limb amputation. And don't leave her, leave a stump.
Postoperative care, we mentioned a few weeks of kind of walking on the lead, harness or sling if needed. I would generally recommend they avoid patients being on areas where they're up high that they could fall down. So for example, I tend to recommend in the early stages avoid them going up and down flights of stairs or if they have perhaps a a garden patio and there's a high wall and a drop, I'd keep them away from that area.
Maybe avoid them walking next to the, the edge of water just because it might be, they might be a bit unsteady on their legs and more prone to falling. Or if they did fall into water, it might be that they would struggle to, to swim if they've just had a limb amputation and haven't had a chance to adapt. And then we're gonna gradually increase our exercise duration, and I'd recommend rehabilitation in order to help and to also help deal with any sort of compensatory problems whereby they'll be using other muscles differently compared to normal.
Complications and amputation, so these are things we want to avoid, haemorrhage, seroma, dehistance, and infections. So classic ways to avoid these would be to follow Halstead's principles of aseptic technique, gentle tissue handling, hemostasis. We want to preserve blood supply, prevent dead space.
And have some accurate apposition of tissue whilst minimising tissue tension. And instead of maybe amputating a whole limb, it might be we only need to amputate part of a limb such as perhaps a digit. Generally the most common reasons for digit amputation would be neoplasia, with the most common digit neoplastic lesion being a a a squamous cell carcinoma.
Melanoma would be 2 and then the the soft tissue sarcomas, mast cells, 3rd and 4th with with osteosarcoma actually being much, much less common. Now something that can be confusing with neoplasia is a deep seated infection with an osteomyelitis. Both of these can cause lysis of bones and and osseous proliferation and it can be confusing between the two.
You can consider a a biopsy, to try and distinguish between them . But I would often sometimes suggest actually maybe just amputating the digit and sending it for histopathology because even if you did have an infection, if it is very, very lytic and destruction to the bone, often it can be very challenging to resolve the infection, and often there can be some permanent discomfort from the destruction to the tissues. Might also consider an amputation for severe trauma to a digit, maybe if there's a deformity, or maybe if there is a severe arthropathy.
We can pop that digit off. So we've kind of run through some of our our learning objectives. We wanted to look at arthrodesis, what are the kind of indications for that, so it's where there has been perhaps a a damage to the joint that's causing pain or an abnormal function.
And by fusing the joint, we can remove some of the pain and restore more normal function to the limb. Joint replacements, can be great for the hip, great for the knee. They're possible for the shoulder and possible for the elbow, but the elbow does come with a high rate of, of complications.
So, in those situations we would want to try to perhaps manage things, medically or during surgery, different surgery earlier in order to try to avoid the need for an elbow replacement. We're at a stage now where just about anything is is possible in orthopaedics and we can replace any part of the the skeleton with an endoprosthesis, so this is possible. And it's a case of weighing up is it the right thing for that individual dog and for that family.
And in situations perhaps where it's not the right thing for the dog or the family, then we can look at amputation, and this can be a a great option for many, many patients in order to get them out of pain as quickly as possible. And in some scenarios we can use part of the body and move it from one area to another. So we showed perhaps how we can remove sections of bone or sections of cartilage from one part of the, the limb or from one joint across to another.
We can also, for example, take bone graft from one bone and put that into another area to help kind of tissues to fuse so we can manoeuvre things around from one part of the body to another. So I hope you have enjoyed this webinar. I hope it's maybe showed you some things that perhaps you weren't sure actually existed and it's kind of opened your eyes a little bit as to what is possible and giving you some food for thought.
Again, many of the procedures kind of covered in this are very complex, and there is a lot of thinking and planning that needs to go into whether or not they are performed, but there are options available that we can offer to our patients and our clients. So if there's anything that's cropped up and you have any questions, feel free to reach out and get in touch. Either drop me an email or feel free to get in touch and message me on social media.
Thanks very much.