[0:00]Hey everyone, we've got another fabulous case study for you. This patient has knee pain. Can you work out what's going on? We're going to take you through the diagnosis and all the clinical reasoning, so let's dive in.
[0:15]Hey everyone, Khalid here, welcome back to clinical physio. Let's go through today's case study, starting with the subjective history. So we have a 60-year-old retired female patient who's presenting to see us with right knee pain. Now her knee pain started approximately 2 weeks ago when she stepped down awkwardly from a ladder. She didn't fall to the floor, but she felt a jarring sensation at her knee as she stepped down from the ladder with her right foot hitting the floor first and therefore taking her body weight as she did so. She didn't feel necessarily a major twisting injury, she didn't feel like she lost balance, as I said, she didn't fall, she just felt a jarring sensation at the knee. Now, two weeks post injury, her pain is still quite severe. It's still constant in nature and it's still painful immediately as soon as she starts weight bearing, and she does explain that her pain levels are high on a VAS scale between 0 and 10, she would probably equate it to between a seven and an eight out of 10. So still quite high pain levels. She's also finding that she's getting pain throughout the night in her right knee, where it's very uncomfortable and it's very difficult to find any kind of position that eases her symptoms. She's taking paracetamol and naproxen to try and help her symptoms, but unfortunately she's not taking, she's not finding any relief from this. And otherwise, she doesn't have any specific major past medical history or drug history. Now, after she injured her knee, she went to the emergency department and had an x-ray, which showed an early level of OA, but it was very mild in its nature. And that is the presentation for this patient. So next we'll head into the objective assessment. So first of all, it's really clear from the beginning that as this patient walks into your clinic, she's struggling to weight bear. She's limping on that leg, it looks like she has a clear antalgic gait, where she's not weight bearing for a long period of time during stance phase because it's so difficult to stand on that right leg and therefore she's really putting very minimal weight through it to try and get her leg through. There's no major bruising or obvious deformity otherwise, but it's clear that she is struggling with her gait. You then palpate the knee and you find that it's quite tender on the medial side of the knee, both at the medial joint line but also around the femoral condyle itself, the distal femoral condyle of the femur on that medial side. We do see that whilst there was no bruising or obvious deformity, there did seem to be an effusion at her knee, which is more clear on the right medial side of the knee. So then we look at her range of movement and we find that both active and passive are the same. We have full range of extension but flexion is really, really limited and fortunately this patient only has around 70 degrees of flexion before she can't go any further and this is limited by pain. So that's the presentation of our patient. In a second we're going to go through the diagnosis and clinical reasoning, but therefore this is your opportunity to put your thoughts down. So take a moment to think about this case, think about what you've heard, write down your thoughts and join us in a second.
[3:34]Okay, everyone, time's up. Let's go through the diagnosis for this patient. So unfortunately, the biggest clear cut indicator to me that something relatively significant was going on was the fact of how much her knee was still painful, irritable, and that she was really struggling with range of movement and weight bearing, even though it was two weeks since this relatively innocuous incidence. So this really did increase my concern that something significant had gone on, and unfortunately that was the case for this patient who was suspected to have spontaneous osteonecrosis of the knee, also referred to as SONK, spontaneous osteonecrosis of the knee. So what is SONK? This is also referred to as an insufficiency fracture or SIFK, a subchondral insufficiency fracture of the knee. This is effectively a form of stress fracture where over the course of a period of time, you may have had repetitive or excessive stress applied through the subchondral bone that means that over time you get this gradual wearing of the bone around for this lady the medial femoral condyle. So it might be that this is something that was exacerbated by the incident with the ladder, but could have been building in the background for some time. What we also see a lot of the time with these kind of injuries is a meniscal root tear. And again, it's sometimes hard to know whether that meniscal root occurs at the time of the injury or prior to then, but what happens with a meniscal root injury is you have the detachment of the meniscal root from where it forms and attaches into the tibial plateau, and with that meniscal root out the way, it effectively moves the meniscus out the way, which means that the bone doesn't have that normal cushioning over the tibia, meaning that you can get that excessive wear, and that may have been the case for our patient as well. So sometimes this isn't easily seen on x-ray, which was the case for our lady because she didn't see any major signs, but ultimately, for a patient like this, when you have that ongoing, really irritable, really challenging picture, it might make you think, I wonder if something was missed on the x-ray. And as we said, this commonly may not be seen and therefore if your patient does have a negative X-ray, you may think about referring on for an MRI scan. That's what happened with this lady, where they found the SONK. So what are the key learning points from this case study? What are the things that I would suggest you take home with you so that you look out for issues and injuries like this in your practice? The nuts and bolts of this case was that you would think that a 60-year-old female with a simple mechanism like just stepping down from a ladder should find some easing in her symptoms over a two-week period. The fact that this patient had such significant and such irritable symptoms two weeks later was effectively the main clinical reasoning I had for something must be wrong. The fact that she still had really severe pain levels, that she was really struggling to weight bear, that she had constant night pain, despite the fact that the injury seemed relatively innocuous and all her X-ray showed was early osteoarthritis, suggested to me there must be something more going on. So this is the really key thing to look out for in these patients when it seems like there's been a relatively normal mechanism or a relatively mild mechanism, but a high pain response, look further and dive deeper into the case. We also know that the medial femoral condyle is the most common location for SONK to occur, and we know that this is three to five times more likely to happen in women than men. So just extra risk factors, moving us in the direction of the spontaneous osteonecrosis of the knee. But ultimately, like we said with this lady, relatively innocuous injury, but two weeks later still having had really high pain levels, really struggling to weight bear, swelling around the knee, and constant night pain and struggling to weight bear, even though there was a relatively mild trauma, think about something more going on. So everyone, if you've enjoyed this video, please support us by smashing that like button. It's the number one thing you can do to help us on our YouTube channel, and if you want more resources from us, please do check out our Instagram channel at clinical physio. Give us a follow there for brilliant resources for physiotherapists. And if you enjoy learning by case studies, please do check out our membership platform, member.clinicalphysio.com, link in the description below. As a part of membership, you'll get access to the case study club, which is a brilliant resource full of different episodes of experts bringing their patients onto the case study club to talk through the assessment, the diagnosis, and all the clinical reasoning to help you with your clinical practice. So thank you so much for watching everyone. My name's Khalid, see you soon, here on clinical physio.
