Après knee prevention and management of knee injuries on the ski slope
Prof Brian Devitt

I am going to start off my talk by showing you a video and this is a classic example of what happens on a ski slope so you have friends laughing at you for falling but often times there is an injury. I just want you to hear what happens now as the skier comes down the slope. Do you hear that snap? If you look at the person that snap is not the skis coming off that snap is the ACL rupturing and you see that the individual is coming down the slope probably at too high a speed and leaning back onto his skis and that is what is causing the injury and this is a classic example of how an ACL ruptures on a ski.

I was lucky enough as part of my fellowship training that I worked in a ski resort in Colorado and one of the fore fathers of treatment of ski injuries is this man Dr. Dick Steadman and unfortunately he passed away last year and he described the ski as the ideal device to rupture an ACL so really you have to be cautious when you are using skis because there are a high rate of ski injuries related to skiing.

In terms of skiing it is good for our business because people go away and injure themselves. It is a hugely popular sport and nowadays you see many people heading away to the slopes as holidays are becoming a little more accessible and it is a very enjoyable pursuit for the whole family but it is a risky sport and you see here the idea of the type of knee injuries that we get and 35% of the injuries occur in the knee and that relates to what Dick Steadman said about skiing because it is a high torque object that can twist at your knee because your boots are held in place there are also other injuries related to skiing.

The equipment has changed remarkably over the last 100 years or so that people have been skiing and what you see here the old fashion skis have much less binding and the boots are not as high on the ankle as they are nowadays.

The modern boot goes 2/3’s the way up your shin and your ankles are essentially fixed that it just allows a bit of flexion and extension at the ankle with very little rotation and the rotation does not occur at the ski but the rotation tends to occur at the knee and that is what happens in terms of getting ACL injuries.

You often hear about people getting skis and then getting bindings and the bindings are tightened up so when you go to an instructor or a person who is giving you your skis they will often talk about the din and the din relates to how tight the boot is fixed to the ski so when you are a very aggressive skier you want the boots to be really tightly fixed to your ski but when you are a more novice skier you want your boots to be able to come away from your ski so if you have any suspicion then you should probably get your din low so your ski comes away from your boot so you don’t turn your boot and your knee to cause an ACL injury.

The terrain and conditions are also very important and you notice here there is very deep and foul snow but equally if you have icy snow or very slushy snow they can grab your ski and increase the risk of injury.

Unpredictable behaviour from people that are on holiday for example they could be drinking too much or they could cause a collision and increase the risk of injury. If we look at the example here this is from Deerpark in Utah where they gave an example of how people cause injuries and they tend to be novice skiers or they are leaning backwards as they are going down the mountain as they were instructed and that creates the skier to be off balance, have their hips below their knees, uphill ski un-weighted, you tend to fall on the inside edge of the ski and this causes the injuries because it has your knee in a vulnerable position as the ski twists. As I said there is unpredictable behaviour and the après ski but it is also when you are coming downhill with a few pints on board and you don’t have that neuromuscular control that you might have had in the morning or perhaps in the morning you are a bit hungover and that too may increase the risk of injury.

On the mountain what can you do? First of all primum non nocere is the saying in medicine to cause no harm so you want to be skiing within your area of expertise so you don’t want to go out of your lane that you might get stuck in or if you go down a slope that you are not able to then you are much more likely to get injured or worse even get lost, die or fall off a cliff. Avoid hazardous conditions like snowing if you are not a very good skier or you have very low light then it’s very hard to see the undulations in the ground and that can make you far more likely to fall over so even on the flat slope it is more likely for you to have a white out and also be well able to stop before your start and this is another example of another collision type injury of someone out of control.

In the clinic what do we do? One of the articles I often quote in my talks is a very eminent professor and he talks about kneemanship and doing an appropriate examination is very important and one of the key factors of doing that is taking a look at history so if someone injures their knee going down a slope, has a fall, tends to hear a snap like the one in the video and it is difficult to put the ski back on and ski down the slope may lead to a more serious injury then someone is taken away by ski patrol but what typically happens is they go to the clinic at the end of the mountain, they get an x-ray and they get a very overpriced knee brace and then they are sent on their way. In terms of taking history you can really tell what’s going on that’s very indicative. When your doing a clinical examination, we look for a number of features to compare to the normal knee because it gives you a good idea of what’s going on but we are looking for the presence of swelling following an injury particularly bleeding because the presence of blood generally means you have torn something. Commonly it is your ACL and that is why it is very important to look at the other knee and you will see yourself when you take off your ski pants that you should probably get assessed. In terms of the clinical examination we go through it in a very systematic manner as we can assess all the ligaments around the knee like the side of the knee so you can often damage the Medial ligament, the ACL is very commonly injured so you will see a very swollen knee as you see in this picture and often in the ski medical facilities they are often very limited, they are quite primitive so what I would typically do is simply do an x-ray to out rule a fracture and that is very important but the clinical examination determines whether you have a severe injury which may be more than one ligament injured or whether it is a more routine injury with just a solitary ligament and that has big implications, a lot of times they will try to sell you a brace and often times the brace is not needed but then they will say lets get an MRI scan and lets have surgery early and this often happens in the US and I would advise against this. I think in the cold light of day you can get further investigations when you come home and get appropriate treatment that is not under pressure by people trying to make money so it is very important to consider that. The x-ray as exampled here can show you what a little flake of bone coming off the side of the tibia and that is an example of what we call a segond fracture and that is indicative of an ACL injury. The MRI’s can be done and often in the mountains they can be poor quality but, in this situation, you can see some bruising at the mid portion of the femur and the back portion of the tibia then you have an injury that causes an ACL rupture. You can do an ultrasound scan and these are cheap scans to get and they often are effective at looking for ligament injury on the side of the knee. Then referrals the referral is very important so getting back to your home countries by packing and getting back to your home country safely and that is very important.

As I said in the cold light of day this when we should see people by assessing them appropriately, we take away the drama we take them back where they are comfortable and they have less anxiety and we can explain things and have the appropriate investigation. Early diagnosis is important we need to know what we are dealing with but also with knee injuries we don’t have to rush into surgery and sometimes there is a decreased range of motion or your muscles are not working properly then pain management is much more appropriate to discuss the treatment, not all knee injuries require surgery and I often tell people to try and avoid surgery if they can but certain situations will warrant surgery and we will go through all the options with you in the cold light of day. We remove the splints as quick as possible and often these splints are unnecessary particularly when knees are meant to bend. We don’t like keeping them straight unless it is a really serious fracture that has to be stabilised but most ligament injuries if the knee is not very unstable then you can move them but that’s not important and being ready for surgery is dependant on motion and that is really the first thing we do. We also get people to weight bare as tolerated as cartilage doesn’t take a joke and cartilage doesn’t like to not be loaded and it is really important that we get you back weight bearing as soon as possible because if you are to have any knee surgery we like to get you weight bearing very quickly afterwards and it is important that you ae bale to do this before surgery and these are some of the things that people do they get assessed and get back to their normal activities.

I am going to go through some of the common scenarios that I see in my clinic and much more frequently at this time of year when they come home from holidays. You see in this picture the type of referral I get and the history is a contact injury turning, he didn’t feel a pop, he fell to the ground, he was unable to weight bear and there was no immediate swelling but there was within 12 hours so we know that something serious has happened. With the clinical examination then he was able to keep his knee in a flexed position, he was unable to activate the muscles at the front of the knee, he is walking a mild length and some swelling within the knee is what we diagnosed he was unable to straighten his knee by 10 degrees but had good flexion then had a one degree laxity or instability of his medial ligament and he had a negative Lachman test so that means that his ACL felt in tact so if we look at the x-rays here we see that this is a juvenile because he still has growth and there was no evidence of any fractures on these x-rays so that’s very reasonable and then the MRI was performed and this is what we see in MRI we look for the presence of whiteness in MRI so that indicates fluid in these sequences as you see on the inside of the knee the fluid is in this region of the medial ligament on the inside of the knee and we see that the ACL is this ribbon like structure in the middle it does have a little bit of fluid in the knee so we know that there has been some damage with the ACL but in this situation it looks in tact which would be keeping with the clinical examination findings.

This individual was just treated non-operatively and allowed get on their way so they escaped a major injury which is good so that is a very common scenario we would see and a lot of times we just give people reassurance but we assess them thoroughly with a proper investigation and this is the second scenario and it was an experienced skier. They had a history of a high-speed fall turning on a steep slope, they heard a loud pop, they tried to stand but the knee buckled, they had to be removed from the mountain by ski patrol and they had immediate swelling. On clinical examination once again when you have ruptured your MCL you are typically unable to straighten your knee and people will see that they couldn’t weight bear, couldn’t stand, big effusion and echymosis which is bruising, they had a grade 3 laxity and they were Lachman positive which meant we suspect that this was a multi ligamentous injury. If you look at the x-ray’s here we didn’t say what side but I presume it is the right knee because the x-ray shows a little bit of bone here and that will indicate that this person has sustained an ACL injury and possibly a higher grade injury and they will go on then to have further investigations so this is the MRI we see and we see lots of fluid within the knee so this whiteness is blood we also can see some bruising so the colour of this knee we see a lot of light grey which indicates fluid within the bone or what we call bone bruising and you can see the meniscus which is this black structure is hanging o0ff the back of the knee so we know that this knee is far further forward so there is something that has been ruptured in this case and as we look into the middle of the knee we see the ribbon like structure that we saw previously has been ruptured so this is the ACL which is torn and this person has got the appropriate imaging and we can now identify that there is a definite tear of the ACL. Then we look at the image of the knee from the front and we see that here we like to see a nice black ligament and that is just this grey colour so we know that the MCL has torn off as well and that would explain the feeling of looseness on the inside ligament. That is a more serious condition and that is a condition that would require ACL reconstruction and MCL repair or reconstruction.

Finally, we have a recreational skier and his history has a twisted knee removing his boot from the bindings, he felt a crunch in the knee and skied on and said “it was fine after a while”, he then said it was very painful that night and he also said he “lasted the week through gritted teeth”. From the clinical examination the alignment was normal, there was small evidence of any fluid or effusion, full range of motion but pain at the end range when they are fully extending the knee or flexing their knee was painful. Pain on the inside of the knee and then a normal ligamentous examination so we are not suspicious of any ligament injury here but we might be suspicious of soft tissue damage within the knee and this is the side view we see of this persons knee and what we are looking at is the meniscus so the crunching sensation with twisting is a very common meniscal injury so what we see here is the meniscus and it should be like a black triangle but you see this white line going through the black triangle and what they have done is they have torn the meniscus. Often times people describe this as being fine at rest when they walk down stairs or twist in and out of a car however they do find some pain. I often tell people it is similar to having a stone in your shoe and if the toe is sitting under your toes it doesn’t cause any problem but when it moves under the ball of the foot that is when it really hurts you like the meniscus when that flap moves it can often give a lot of pain so we try to treat this non operatively to begin with but if the pain or symptoms are persisting beyond 3 months or there are obvious signs of displacement on the MRI scan then we would often have to do an arthroscopy and just remove that torn portion of the meniscus. This is another example of that where you see that the meniscus is just pushed out to the side there and there is some displacement.