 Now let us have a short discussion about the posterior cruciate ligament. Let's begin with the anatomy of the PCL. So posterior cruciate ligament is a strong ligament, it is twice as strong as the anterior cruciate ligament. Isolated PCL injuries are less common, more often it occurs as a part of multi-ligamentous injury. PCL also has got two bundles, anterolateral and posterior medial. Now that's the reason why I told you to remember the word ample for ACL. So if it is anterior medial in ACL, it's anterolateral in PCL and if it is posterior lateral in ACL, it's posterior medial in PCL. So that's how you can remember the bundles in both the ligaments. So here you can see as we have seen in the ACL also you can see the two bundles very well. So this is your anterior lateral bundle and this is your posterior medial bundle very well seen on axial as well as coronal images. So this is your image of the entire ligament on a sagittal image and you cannot differentiate between the two bundles easily on a sagittal image. The ligament itself has a jet-plack appearance because of the tightly bound fibers. So now let us discuss about PCL trauma and record degeneration. PCL injury can be of two mechanisms, one is a dashboard injury which usually happens in car accidents where there is an impact of the knee against the dashboard of the car. And second is a hyper extension injury as you can see in this patient the knee is going into hyper extension. So whenever there is a hyper extension injury what happens is the anterior femur will impact against the anterior tibia and what you will get is a classical kissing contusions. So by kissing contusions I mean that the two contusions are adjacent to each other and so this is the classical PCL injury pattern when it happens with a hyper extension injury. Now again just like in PCL injury the injuries can be acute and chronic. In acute injuries you need to mention about the bone marrow edema pattern, the status of the ligament itself and in chronic injuries you need to see whether the ligament is healed well or not that is well remodeled ligament or a poorly remodeled ligament. Usually PCL injuries if they are not a full thickness they tend to remodel well. So let us look at the entire spectrum of the ligament injuries now. So this is a low grade injury but you can see that there is some intrasubstance hyper intense signal within as I have told you the PCL entire ligament is jet blackened colour. So any intrasubstance hyper intense signal within is abnormal. So this is a low grade injury you cannot see a complete disruption of the fibres in this patient. Here you can see that it is a high grade injury so there are few fibres which are intact so it is not a full thickness there but most of the fibres are disrupted against this normal ligament. And in this patient you can see that there is a full thickness there so there is a complete disruption of the fibres in this patient. You can see there is a thin fluid signal intensity that is going across the ligament fibres. You can also have single bundle injuries even with PCL injury and that will be very well seen on axial images where you can see that this bundle is injured whereas the other bundle it looks pretty much jet blackened colour and appears intact. This is the patient with Osteos emergency at the TBL attachment so you can see that in this patient also you need to mention the same three things that is the dimensions of the Osteos fragment, the superior displacement of the Osteos fragment and what is the status of the ligament itself and these Osteos emergency can also be very well picked up on radiographs as well on a particularly on the lateral view. So this is the entire structure where you have the low grade injury, high grade injury, full thickness there and single bundle injury which will obviously be well seen on an axial image and an Osteos emergency at the TBL attachment. So again this is the entire reporting pattern where you can see that this first you need to mention is the bone marrow edema pattern. Next you need to mention about the PCL itself what is the grade and the site of injury. In case of Osteos emergency mention about the size and displacement of fragments and just like in a CL you need to mention about the other soft tissue injuries particularly posterior lateral coroner injuries are common and in case of chronic PCL insufficiency you need to mention about the cartilage status in the patient. So if you put all of this in the report again you are answering all the questions of the orthopone. So now in new quality generation again the same concept as in a CL the ligament will appear bulky and hyper intense but if you will see that the ligament fibres you can pretty well very well see all the ligament fibres in that. So this is how you differentiate a pair from the bukoid posterior cruciate ligament and this patient also has an intrasubstance ganglion cyst. So what are the key take home points look at the ligaments in all the three planes look for the ancillary findings that will help you to diagnose injuries when you are in doubt. Please please look at the radiographs they can be your real friends particularly to pick up small fractures talk to the orthopod or get the clinical notes when you are in doubt avoid satisfaction of search if you have seen that there is a ACL injury please look at other soft tissue injuries particularly the smaller ones otherwise the patient may land up in a graft failure and make sure to look at previous imaging because these ligaments can undergo remodelling and remodelling does not mean that functionally the ligament is stable. So if you have a previous imaging you can put forth a better report and send it across to the orthopod. Thank you for watching the video. This was the last video of the entire session of the cruciate ligaments imaging and I hope you thoroughly enjoyed this session. 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