 Okay, so today we're going to start out with bucket handle tears. We're into the menisci once more, and I would encourage you to go back and look at our first two forays into the menisci to learn a little bit more about anatomy, but we're going to drill a little bit deeper today into the concept of bucket handle tears. So let me draw my meniscus, and I will try and do my best to make it somewhat three-dimensional. And we've said in the past that bucket handle tears usually begin as vertical longitudinal tears. They're often in the middle, and usually these vertical longitudinal tears in the middle don't persist as simply vertical tears. They do progress, and I've had innumerable instances, especially of professional athletes that chronically complain of pain and kind of a vague sensation of clicking. The center of the meniscus is absolutely normal, and then when you go back in retrospect, you can see a quarter of a millimeter line through the center of the meniscus that was barely visible that even in retrospect is hard to see, and that was the initiation of what eventually became a meniscus that split into two parts, a so-called bucket handle tear. So there's kind of a pre-bucket type pain syndrome that may occur. Now these vertical tears will start to widen and gap, and they'll get a little bigger and a little bigger and a little wider, such that this portion of the meniscus starts to migrate inwards in the typical classic bucket handle tear. So you get something that looks a little bit like this with a big hole in the center. Now if you were to perform a coronal slice through here, such as this, what might you see? You would see a truncated portion of the meniscus that looks like it's chopped right there, and it's going to have a specific rim to it, or a width to it, and that's important because they're going to have to sew one piece, namely this inside piece right here, which looks something like this, back to it. So if you have a very thin rim out here, it's nice to know what you're sewing to. You also want to know if this rim has a horizontal tear in it, which it may, which decreases the likelihood that you can sew Humpty Dumpty back together again. Now what's going to be in here? Blood, inflammatory tissue, a little bit of fluid, but this configuration is going to persist slice after slice after slice. You're going to see it here, you're going to see it here, you're going to see it here, and then all of a sudden it's going to go away. The meniscus is going to come back together again, unless the bucket handle tear goes all the way out the front. So the bucket handle tear could do this, and even this piece can start to sort of migrate in. Let's erase, let's get our eraser up here a little bit, erase that piece, and now you've got this big, huge fragment all the way in the front, but not quite all the way to the back. So the separation will persist all the way in the front, and continue on as you go back with a series of coronal slices until you get all the way into the back. Now there could be what we call the free fragment bucket. I've just illustrated for you one that extends all the way anterior, the so-called anterior bucket. I showed you initially the classic bucket, the one in the center, but let's take the situation where we have the free fragment bucket. So here we've got the outer rim, and then here we've got a piece right here, and they're not attached to each other anymore. They kind of squish down by the femur and the tibia. So then you're going to get something where you have a truncated meniscus in the back. Let's change colors actually. A truncated meniscus in the back, because this was attached back here, maybe another area of truncation, and then continued separation of two fragments all the way from front to back, so you never see these two fragments join ever again. And it's even possible for this piece, which I will use my little light blue drawing here, it's even possible for this piece to go all the way back and for you to have two pieces in the coronal plane, like this, on every single slice. That's what I call a coast to coast or a complete anterior to posterior bucket handle tear with a free fragment. Alright, so now let's erase and start with a clean slate and show you a few other configurations of buckets. So let's assume we have a bucket handle tear with a big hole, started out as a vertical tear, here's our hole, and now this piece, which is still attached by a little twig here in the back, kind of migrates forward and it can dip right underneath the anterior horn. In which case when you perform a sagittal view, it may look like you have a piece of meniscus here and a piece of meniscus right behind it, in fact it may bolster up right underneath it. So you have these two meniscoid looking structures, you do a sagittal and you've got a double meniscus sign. Or this could happen. You could have the same thing, a big hole in the middle, pardon my squeaking, a huge tear and then this time our piece kind of wanders in front of the anterior horn and looks something like this. Again, another double meniscus sign if we do a sagittal, you'll see two meniscoid looking structures. And to make matters more complex, you might have a transverse ligament lurking here anteriorly. So you might have a little round structure and a triangulated structure or some deformed triangulated structure and another one behind that and then you might even have another little rim before you run into this hole so it can get rather complex. You can have two, three, and even four areas of hypointensity in the anterior aspect of the knee. Now, do buckets ever do the opposite? Do they ever go backwards posteriorly? Not very commonly. Most of the time they do migrate anteriorly, but they can twist. So if this thing's pretty narrow, you can get a pedicle and the bucket handle tear can actually turn on itself which makes things rather complex. Now this piece of the bucket right here, which I've colored in green, that's the part that you're going to see on a sagittal. Let's make our sagittal view nice and blue. Our sagittal slice goes through it and you're going to see a bowtie looking or rectangular structure in one of these central slices and that structure may sit right underneath the arching posterior cruciate ligament that's going right over top of it creating the double PCL sign of a bucket handle tear.