Trauma Series: Knee trauma | Fahad Hossain



This is a 45-minute on-demand teaching session that is relevant to medical professionals and covers the management of knee dislocations. The talk will be led by Mr Hossain, a consultant orthopedic surgeon and director of R&D for the trust he works at. Mr Hossain will discuss the epidemiology of multi ligament injuries, the classification systems, clinical assessment and the anatomy of the back of the knee. Attendees will also have the opportunity to ask questions throughout the talk. At the end, there will be a feedback form and each attendee will receive an attendance certificate. Join now to delve deeper into the management of knee dislocations.


Please Note: As this event is open to all Medical professionals globally, you can access closed captions here

Joining us today is Fahad Hossain, Consultant Orthopaedic Surgeon from Walsall Manor Hospital teaching on Knee Trauma

Learning objectives

Learning Objectives: 1. Understand the significant implications of a knee dislocation, including potential amputation in up to 20% of cases. 2. Understand the Shenck classification of knee dislocations. 3. Recognize the high index of suspicion that is necessary when viewing plain x-ray and MRI images of knee dislocations. 4. Understand the potential for concurrent vascular injuries with knee dislocations, up to 40% of cases. 5. Be able to identify the anatomical structures of the back of the knee.

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Computer generated transcript

The following transcript was generated automatically from the content and has not been checked or corrected manually.

We're in. So welcome to medical education. My name is I'm usually on the support desk, but it's really, really great to have you all today for this talk. We are joined today by Mr Jose who will chat to you about management of knee dislocations. Um The talk will be about 45 minutes and then there'll be time for questions at the end, but please put your questions in the chat and we should get to them either throughout the talk or in the last 15 minutes. Um At the end of the event, there will be a feedback form that will be emailed to you and once completed your attendance certificate will be on your med account. Um So a do I'd like to welcome Mr Jose. Uh Good evening all. Uh My name is Farha. Thank you Jingjing. So firstly a big thank you to medal for considering this. And uh I think this is a very um noble effort to try and get education uh around the world in places where it's probably most required. So I am a consultant orthopedic surgeon who specializes in knee, soft tissue, knee, and arthroplasty work. And I also happen to be the director of R and D for the whole institution, the trust that I work at. Um So I have some interest in research, particularly pertaining to orthopedics and knee surgery. So what I'd like to talk to you today about is um multi ligament, knee trauma and how to manage this. Um The talk is sort of directed more uh at a trainee or a registrar level as we are known as we know trainees in the UK. So firstly, I have no confidence of interest to declare. So the the objectives of this uh teaching session would really be to try and understand how to manage a knee dislocation as you would as a day one consultant or somebody who's a senior trainee or any sort of trainee. And perhaps we'll touch on the more recent literature and have a more evidence based approach to definitive management. Although, you know, that's a whole topic in itself and uh we'll probably just touch on that and talk about it more on the Q and A section if required. So, a knee dislocation, well, uh essentially a multi ligament injury or a knee dislocation is a true disruption of the tibial femoral articulation. This typically happens in any direction. Um and often it involves at least two or more ligaments of the knee, but um can also involve more, it is a very significant injury, um has a potential for uh vascular injury with the ischemia. Um and also um depending on the mechanism of injury and this uh the amount of energy that's required to cause the injury um has a very high incidence of uh neovascular injury in the region of about 16%. But some literature quoted it as high as 40%. Um Again, the significance of the injury is indicated by the fact that, you know, one in five people may also have an amputation, uh which was shown in the lower Extremity assessment project, which was which we all commonly know at the study. So, um just to kind of illustrate the point, this is the interactive section uh of, of my talk really um is this is an x-ray of a, of a plain knee and I was just wondering if any of the uh delegates were able to see any sort of um any findings on there. So I don't know if anybody can see the uh see what I see the x-ray and you know, if anybody wants to comment in the chat box about what they can see any trainings out there. No, I think our attendee may be a bit shy, nothing in the comments, nothing in the comments. Um OK, that's fine. So essentially, you know, for, for, for most purposes. Well, I have given this talk to trainees before a lot of people would assume that this is a normal looking x-ray and that may well be the case, but there are some salient features here. Um If you look at the lateral view x-ray, first of all, you can see that um the posterior tibial condylar border sits more posterior um than the posterior femoral condyles. And that in itself just by virtue of the x-ray gives us a small suggestion of whether uh there is a ligamentous injury, um mainly the posterior cruciate ligament. Um but perhaps what's more important is uh looking at the A P view of the x-ray. Um And if I was to zoom in, you can probably see that there is a slight asymmetry of the uh o of of, of the liga uh of the ligaments there, uh sorry of the tibi, femoral spaces on the medial side, it is widened more so than the lateral side. Um So the, the basically the idea is to try and uh establish that, you know, a lot of these patients with multi dislocations they present once they've had a spontaneous reduction of their initial insult to injury and the x-rays and the first presentation in the emergency department or when you see them for the first time, um may look fairly innocuous, but actually, the injuries may be more severe than you think. And that's the MRI scan of that same patient. And what you can see here is that there is a significant uh medial side of injury um with contract to bone bruising on the lateral side. And then the MRI slices below, you can see that there is potentially uh high signal within the PC L as well. Um suggestive of a poster ligament injury. So, the epidemiology of this uh of this type of injury. Well, actually multi ligament injury, certainly where we are in the western world is, is reasonably rare. Um The qula is 2 to 29 per million orthopedic injuries. And like I've said before, um the first presentation, uh at least radiographically can look fairly, uh fairly minor, but, you know, you have to have a high suspect, a high index of suspicion because up to 50% or half of them do reduce themselves before they actually get in to see you in the hospital. Uh for some reason, it's more common in males than females. Um And you could probably try and categorize the demographics of these patients in or the or the etiology if you like into 33 categories. First is the high energy mechanisms where people are involved in, you know, motor vehicle accidents, uh road traffic, uh injuries or falls or crush injuries where, uh you know, there is massive trauma and injury and often these may be uh associated with concurrent um, fractures of the bones, um very particularly periarticular fractures. Then there is the intermediate to lowery injuries. Um accounting for a third of dislocations. These are people who are playing sports and they have noncontact, twisting or significant contact, twisting or tackling injuries. Um And then there is the cohort that perhaps uh certainly where I work, I see uh reasonably fair amount of is the high BMI people who, who are very sedentary lifestyles. But because of uh because of the weight and the conditioning of their soft tissue, they tend to have uh you know, low energy mechanisms but significant injuries, often these patients have a very high BM and they don't have any sort of sporting activities or practices. So, classification, historically, there were different classification systems. We tried to talk about uh the injuries in terms of the direction of uh uh of the mechanism of the actual uh of the injury itself. Although that's been difficult to apply because we tend to have spontaneous reduction. As you know, by the time they get to get the clinic, the most prevailing um diagnosis. Sorry classification system is based on uh the ligaments that are injured that's known as the Shenk classification and divide basically 1 to 4 plus a five ft fracture. So one is essentially uh a, a ligament injury, two ligament injury where you've got one of the cruciate ligaments plus a collateral A KD two will be two, cruciate KD three is three ligaments. Um and that can be subdivided into KD three M and KD three, L for post lateral corner and uh medial side. Then there is KD four where you have everything that's gone and KD sorry KD four and then KD five with, with the fractures. Um So that seems to be the classification that most of most of us as orthopedic surgeons tend to use currently. So, clinical assessment, well, like any other high trauma injury, the focus of treatment, uh focus of assessment should be uh using the A TLS protocol airway breathing circulation and disability and exposure. Um Only once you have ensured that your primary survey and you know, you've done all your secondary survey and make sure that um the airway breathing circulation is fine, we will then focus on the knee. Um And when we focus on the knee, it's important to make sure that all limb threatening sort of uh factors have been addressed. So first and foremost, ensure that there is per fusion, um you reduce the knee, if it hasn't reduced, then you're seeing it from this position um and stabilize it so often these knees, um if they're not self reduc or come with a grossly deformed leg, um the significance of the injury might be such that uh there may be puckering of the skin due to button holing of the structures such as the, the bone through the uh the medial collateral ligament and the capsule. And of course, a lot of these patients who present with significant swelling um and that hematosis, but that may not be the case always. So this is an example of a patient who's had medial puckering of the skin as you can look at the knee that's on the on the on the left of the screen is the anterior aspects of the knee and, and to the right of the screen where the white arrow is, that's the medial side of the knee. And this puckering is suggestive of the fact that the femoral condyle has actually cut and hold through the MC L. And that's why it's not reducible. And it's important to make sure that this is reduced. Um at least as a basic sort of um first aid measure before definitive management can be considered vascular injuries are extremely common, like I said, so, up to 40% of people will have um concurrent vascular injuries with uh uh with these multi ligament dislocations. Um And of course, once you look for the hard signs of vascular injury and we all know what these are. Um you know, you've got a cool pulseless uh leg with this, you know, uh with the white foot, if you like absent pulses and poor and slow to biliary refill, um This is just to kind of bring everybody back to see if we can name any of the blood vessels or just a bit of anatomy. I don't know if anybody's going to be able to interact with us. I don't think so. I'm just gonna skip this section. So just to remind everybody of the anatomy of the back of the knee, that's the tibial nerve. Number two is the common peroneal nerve. Uh Number three with the sciatic nerve where the two branch off before it. Uh that's the lateral cutaneous nerve. So, communicating branch. So nerve, the medial sural nerve, cutaneous nerve. Where did we get to you? You just kind of that po ovarian artery? Um nine of the glip branches and the natural side, 10 other nucular branches on the medial side, the small sub vein muscles, these are easy, same tendinosis, same nos on the medial side and the me of the gastro, the lateral and the biceps Noris. Um Again, another diagram to illustrate the vascular supply on the back of the knee, which is what most of the time uh the injuries have happened with. So if you don't have hard signs of uh vascular injury, uh then where do we go from there? You have to have a high index of suspicion uh for assessment of vas uh sorry for vascular injuries and therefore the assessment. Um and if you have, if you have the hard signs, it's quite obvious, you know, you can go ahead and do an arteriogram or take the patient straight to theaters and uh stabilize and then undertake exploration uh of the vascular vasculature, at least in our country or at least where I am uh in conjunction with a vascular surgeon. However, the problem lies in when you have patients who don't have heart signs. Um but you suspect an injury or there is perhaps a partial vascular injury. And how do we, how how do we, how, how do we assess those patients or how do we preempt those vascular injuries? So there's no consensus on, you know, when we should be doing, you know, arteriogram or noninvasive versions of such, such as a CT angiogram or arteriogram, you know, do we do them in all cases or do we only do them when they are hard signs of ischemia? One would argue that if you had hard signs of ischemia, then you already know and, and perhaps you should consider having surgery. But then there's also the argument that if you were to do the angiogram first, uh you may be able to localize where the injury is and said you will be more efficient and effective in doing that first. However, there has to be balanced with the delay to surgery that may ensue. Um And this is certainly an example of a 3D reconstructed CT arteriogram where you can see uh a vascular injury or there is poor flow um at that level there. So what is the current thinking with respect to vascular injuries that do not necessarily have all signs, although there may be a latent period of vascular injury and it may well be related to the actual dislocation itself. So there may be a kink in the vessel um because uh uh you know, an after reduction or after uh or before reduction, uh which may be uh limiting the flow or perhaps more commonly, there may be a subtle partial injury such as an intimal injury that doesn't necessarily present with hard signs straight away. But over time can progress to a fullblown uh vascular injury or perhaps uh you know, due to poor flow as a result of the intimal injury leads to thrombosis. And thereafter, um you have a vascular fusion. So what do we do? Well, the paper published in 2009, which suggests that there has to give a, a way to stratify these patients. Obviously, if you have hard signs of uh a vascular injury, then the other is to be taken for ac T angiogram straight away or taken for patient for expiration. Um such as absent distal pulses, if distal pulses are present or there is asymmetry or there is uh a sluggish situation. Um Then we rely very much on the ankle, brachial pressure index where you take the systolic BP at the ankle um of the affected limb and the systolic BP in the arm. And if the ratio is less than 1.9 there, and then, but you can't necessarily see hard signs, then perhaps there may be an intimate injury or some blood flow, limiting extrinsic factor. And there are, and therefore, I want you to consider an arteriogram there if distal pulses are present. But you know, you're worried that this patient may have vascular injury or something, you've been tearing and what we certainly do in our practice is to uh observe. So, you know, you know, I would, I would do, I would advise my juniors who are on call to make sure that serial ankle baker pressure indexes are done. And as soon as uh the ankle baker pressure index drops below 0.9 then one would be concerned that there may be an, you know, an ensuing or developing vascular injury that may require prompt assessment and intervention, nerve injuries are also very, very common, most commonly the lateral side. So if you've got post lateral corner injuries or rotatory inst on the lateral side, um these injuries can happen uh especially if there is a an injury to the leg where you have a varus um direction of a deformity to the leg. Um And these injuries are traction injuries where the, the common peroneal nerve winds around uh the fibular head and neck and and it tends to get injured over there. This is another x-ray uh perhaps from a, from an interactive point of view. Um Is there anybody that can uh see thing and perhaps we may get some people to try and interact with us on this occasion. Um Anybody, nothing on the chat so far, nothing on the chat so far. Ok. Well, again, I'm I'm uh I'll just, just kind of uh I put this extra up once again to illustrate how subtle the findings may be, especially when these patients return back um or present to any for the first time with a spontaneously reduced leg. So you may, you may see it clinically swollen, um leg, sorry, swollen knee, but may not necessarily see obvious signs of the x-ray. But I don't know if this is projecting very well. But above the level of the fibula, you can see a small speck of bone if you like. Um And if you can appreciate that, then I think you've done well to pick up on the, on a possible post, lateral corner or a lateral uh laterally based lateral ligament injury. Now, a lot of people will say, you know, this is a second fracture. A sago fracture happens more uh more distally at around the level of the tibia. This is what we would call an arcuate sign, um which is indicative of a possible um possible corner injury. And again, uh this is uh an MRI that you can see which would suggest from the same patient that there is a significant laterals sign of injury where you've got invagination of the lateral collateral ligaments into the uh into the TB femoral space itself. So, like I said, 40% of cases, nerve injury, common cranial nerve is the most common. And if you do see this um where you know the person, uh a patient presents with uh a foot drop if you like um as far as presentation after potential dislocation or you know, a high trauma or low trauma dislocation then we have to suspect that there has been a laterally based injury around the lateral collateral or the corner. Um So how do you manage this in the straight off? Well, foot drop require orthosis to prevent uh Corus contractures. You know, I, I guess when you're dealing with the A TLS uh side of things, that's not so much a priority. But uh once the patient has been stabilized, um it's important to make sure that that does not get um missed. And uh you know, problems or contractures are addressed preemptively by giving them a foot drop splint um during surgery, um, you could consider um neos or nerve exploration and decompression and certainly when you're doing cross lateral corners, um we tend to, we tend to isolate the nerve and move it away uh to allow, to allow any sort of uh to minimize any risk of pressure. And of course, if that's not the case, then, you know, if you have no improvement by the time of definite surgery, you should consider exploration anyway. Um If there is no continuity um or improvement in nerve function by three months, then I would suggest that we refer this to a peripheral nerve expert surgeon to consider surgical intervention further by that time. Um And I think to discuss those would be the sort of out of the, of this now. So initial management, like I said, A TLS uh principles um reduce the knee dislocation if the patient has got a grossly malformed leg, um immobilize it. Now, this can either be in a plaster um or an external fixator. We tend to use an external fixator um in an institution because it could, it confers better stability. And once you've done that, we would obviously reassess the limb and particularly with respect to vasculature and uh the nerves, like I said, often, some of these joints may not be i reducible um because there's been button holding of uh of uh of bony structures through uh ligaments or capsule, most commonly on the medial side. And I have had in myself, had to twice at least do an open approach to try and get this reduced. And um we should certainly be consenting our patients when they're taken to theaters for uh reduction of such injuries for an open approach and procedure, especially when uh such features are seen clinically. Now, definitive management is uh is an area of content. And actually, if you spoke to maybe three or four different knee surgeons, everybody will have very different opinions about, you know, how to manage multi ligament injuries. And I'm afraid uh there is no clear consensus on this. Um This is a paper that will tell you uh or at least gives you some evidence based approach to decision uh making in uh knee surgery. And I would encourage you all to kind of have a read of this. There are more operative versions of this as well. What we certainly do know is that surgery is better than non operative management for multi ligament reconstruction. And that's not to say that there isn't a role for uh no management. And there certainly is. I have had patients in their, in their seventies who have had no energy mechanisms and have had clinically apparent uh um multi ligament uh injuries and I have managed to treat them in cost mobilization, allow everything to scar up, um which then gives them a stable knee that they can walk on. Now, that is perhaps more rare than common. Um And the commonest scenario is for the young active ambulatory patient um to have surgery as non uh intervention doesn't result in good outcomes compared to surgery repair versus reconstruction. Now, there is this argument that in the acute setting when the patient has first presentation of multi ligament knee injuries that you could consider repairing them. Um What we do know is that at least with the lateral side, the post lateral corner um repair doesn't work as well as reconstruction. Um And that's certainly something that we need to consider. So most post lateral corner injuries in my hands, they get reconstruction um unless they present with a bony a bulging fracture, such as you know, if there, if there has been a bit of bone that has come away from the fibula. Uh In those cases, I would consider doing a uh a repair but that's perhaps not as common as the reconstruction, the medial side, um they tend to heal their cell, heal themselves. So, in some cases, you may want to consider um non operative management on the medial side of the injuries, cruciate ligaments. Again, there's no clear answer here. Um I have a tendency to reconstruct them. Um because the prevailing evidence would suggest that outcomes are better early versus uh delayed surgery. Uh Again, this is a contentious issue. Early surgery basically means um you know, more clear anatomy, less scar tissue, um therefore, potentially easier surgery. And if for any reason, you were to consider repair, then it may well definitely be better to do so in the early period. And there is some evidence to suggest that early surgery is good but acutely early surgery uh within days of uh the injury itself also does predispose you to high risk of a fibrosis and reduced joint range of motion and a lot of stiffness afterwards. But if your facility, if your institution or your practice involves as an area where or or resources where you can have aggressive physiotherapy and rehabilitation, then that may well be a better option. It is perhaps more cost-effective because you get to do everything all in one bill and the patient stays in the hospital for less time, you know, less multiple surgeries and you know, you, you're rehabbing them and getting them back to movement and motion early. Um Unfortunately, where I am, that's never not always the case. Um So we may, you know, I tend to do stage surgery more often than not if I'm being honest. Um And while there is a school of thought that says that do all ligaments all together early, um there is literature to suggest that that doesn't necessarily always have the best outcomes and staged surgical treatment does yield good functional outcomes as well. Um Unless you're a sports person. So there's been a very recent paper by your father and his group that would suggest that uh for sports people, if you have multi ligament injury, addressing all of those ligaments together and then getting aggressive rehab straightway afterwards, helps them return back to sports um earlier and better than if you were to do it staged. But that's, that's not a of people that we generally always see and by and large, most of the evidence to suggest that you can do either I tend to do stage because it's just easier and I I it's what my resource allows me to do. So in summary, multi ligament injuries are perhaps rare compared to other fracture type injuries. Most of these patients come back uh with spontaneously reduced knees and x-rays may be very subtle. Therefore, you must have a high index of suspicion. A lot of these are associated with neurovascular injuries and I would encourage or recommend a multidiscipline approach. So, uh you know, it's important to get vascular teams and peripheral nerve injury teams involved early especially the vascular teams. Um selective arterio with ankle brachial pressure index monitoring is very important. Initial management would be like for any sort of high energy trauma using a TLS principles. Once that's been done, the priority would be to salvage the limb and try and reduce the limb threatening uh factor. So reduce rep of use, immobilize and restrict using plaster or exi then plan. So pan scan and plan is a principle that we apply for most trauma injuries here. So we would uh reduce span it and then reassess and plan it. Thank you very much. Thank you so much for your presentation. Um I don't think there's any questions in the chat at the moment. Um But just a reminder to attend these, please do feel free to put your questions in the chat. Um We maybe give it five minutes so people can process everything. Yeah. Yeah, no problem. So what's interesting is I was just looking at the poll. Um And it says that a lot of people, you know, in your clinical practice, which diagnostic modality do you most commonly rely on unsuspected ligamentous injuries? And everybody says 72% would look at MRI um 18% said x-ray and 9% said clinical examination. That's very interesting. Um So uh I would, I would, I would sort of in part agree with that, but I, I want to just highlight the importance of some of the other features. So I agree an ultrasound doesn't necessarily help. But for me, um beyond an MRI the clinical examination is perhaps more important. Number one, because of the concurrent high incidence of injuries, um vascular injuries and um sort of nerve injuries. So that's why a clinical examination is most important. And actually there is a lot to be gained from doing examinations under anesthesia uh of these patients. So while I do have uh I do do MRI S in my practice, that decision making for surgery for me comes from uh clinical examination under anesthesia. So just just to kind of highlight that for a lot of people. So, you know, I would always examine the patient's ligaments with an under x-ray and then compare it to the other leg to look at the differences. So, objective differences in um valgus and varus stressing um is something that I use quite a lot or PC L stressing under x-ray guidance comparing to the other side, those are more helpful for me to decide about surgery than an MRI because an MRI will pick up a very subtle PC L injury which may not be clinically very significant. And then in the context of a massive multi ligament injury, you're kind of left with the decision to well, do I go in and operate under A PC L or do I not? Because you know, the MRI shows that there is a PC L injury or there may be some high signal in the fibers of the PC L. But does that necessarily mean that I would need to go in and reconstruct the PC L? Probably not. Um And under those circumstances, what I would tend to do is do a PC L stress view. So I would examine myself and stress the PC L under x-ray and compare it to the other leg. And if I can see a significant posterior drawer, um in reference to the li that's nine, then I would uh perhaps offer them PC R surgery as opposed to just basing it on an MRI scan. And I think the same principles apply to the uh to the other ligaments as well. That does make a lot of sense. Uh There's another poll we'll just release into the uh audience if you would like to chat through that as well when, when faced with a patient who has a potential potential. So uh all of the above really, um for me, you know, I, I understand that uh II I would talk my visual aids and, and I will discuss with them the potential consequence of the non treatment. Um And I would actually give them, I would talk about the literature to them in regards to what happens if you were to not repair the meniscus. So, in my view, especially in the young active patient, there is no, there is no role to uh at least not try and repair the meniscus because a damaged or an absent meniscus um is basically a precursor for progression to arthritis. And we certainly do know that. Um but what I wouldn't do is repair the meniscus and ignore the ligaments. Now, just, just to kind of digress a little bit in terms of joint preservation. One has to understand that there is a hierarchy, a pyramid or a joint preservation ladder which you like. Um And, and the principles of joint preservation is you must always address this perhaps more in the chronic setting, but certainly applies in all cases is you must address the alignment which perhaps in the context of multi ligament knee dislocation, it's not so much of a problem, but once the alignment of the knee is OK, you address the stability of the knee and this is where the ligaments come in. So you must address the ligaments, make the knee stable. Um and then address the meniscus. And then once you've address the meniscus, you address the cartilage. So if you've got a multi ligament knee injury and you've got concurrent meniscal injuries, yes, you must address the meniscus. But before you address the meniscus, you must have a stable knee because a meniscal repair is only going to be successful if you've got knee stability. Otherwise, if you um if you have a, a knee that is rotatory, unstable or coronary or sagittally unstable, and then you go and be the meniscus, you know, the abnormal forces that will go through that meniscus will render it to fail very quickly and very easily. Hence this concept of a joint preservation, another alignment, stability meniscus cartilage. So uh those are general principles that as a knee surgeon we should follow. Um and in the context of the acute knee injury, perhaps the alignment is not so much of an issue because that's an acute presentation. But definitely you must address the ligaments before you address the meniscus. But definitely don't ignore the meniscus either because if you, you know meniscus is important feature of knee function and health and once the meniscus goes, people develop arthritis very quickly. And I think we have a lot of medical literature to support that concept. Now that makes a lot of sense. There hasn't been any other chat uh questions in the chat. Um Otherwise, um I think we might as well round off the evening. Thank you so much, um Mr Hussein for teaching us today and thank you as well to the attendees for joining us. I'm just going to pop a quick message into the chat. Um Just to remind you that the feedback form will be emailed to you. And once you complete that feedback form, your tender certificate will be on your medo account. There is a session in two days on managing MS and low resource settings if you're interested in joining us for that as well. And do follow me education on the our medo account. Um just to keep in touch with what events we've got going on. Thank you very much, everyone. Thank you. Thank you very much for having me.