 Srijita from Apollo Hospital Kolkata. Although I have already made a tutorial previously on MRI of knee tears, today I will be focusing on MRI of root tear. Now why do we at all have to know about root tear? Now meniscus is a vital structure to normal knee function responsible for body weight distribution of the knee joint. The weight bearing function of the meniscus is by circumferential hoop tension and is directly associated with prevention of early osteoarthritis changes. So, to maintain this hoop tension, the attachment of the anterior and the posterior horns of the meniscus to the TDR are very important. Herein lies the importance of detection of meniscal root tear. Today we will be having the tutorial in a video mode. The first three videos will be showing the normal anatomy of the meniscal root. The next two will be showing videos of cases where undetected root tear has led to a lot of complications like arthritic changes, subconural changes which you all see. Plus we also should know how a post-op meniscus root tear looks like. Hope you like my tutorial. Now let's look at details of meniscal root tear, how it appears normally in MRI. Some abnormal cases I will show you quite a few videos and still pictures and also complications of untreated root tear and finally a little few words about meniscal root repair and the post-op MRI appearance of such cases. Let's start. Root tear is a subtype of a radial tear and can occur in both medial and lateral meniscus but most commonly it affects the medial meniscus posterior home where it is thought to be representing a degenerative state. It mostly affects middle-aged females with classical symptoms that point towards the diagnosis. The patient who has otherwise good activity suddenly feels a pop in the back of the knee either while squatting down or getting up from a squatting position and feels deep pain localized in the posterior aspect of the knee and within few weeks the patient is unable to bear weight anymore and goes to the orthopod almost in a wheelchair. On examination the tendon is typically in medial meniscal root tear is localized more posteriorly. There is pain in the joint line from the medial aspect gradually posterior medially. MRI does confirm the diagnosis and finally the orthopedic surgeon takes a call on various factors after seeing various factors the age of the patient, the profession of the patient, the symptoms of the patient, confirmation of the diagnosis by MRI plus associated conditions like the amount of cartilage damage, amount of subcondar degenerative changes whether or not there is a subcondar insufficiency line stress fracture and then only decides whether to arthroscopically repair it or not but whenever possible it should be tried to be repaired arthroscopically and we'll come to the details later. Coming to the anatomy of the meniscal roots menisci are C-shaped structures the medial meniscus having a wider C and the lateral meniscus having a smaller C. The anterior transverse ligament or the geniculate ligament connects the anterior horn of both the menisci anterior root of the medial meniscus is the largest footprint which is located anterior to the root of the lateral meniscus that is anterior to the anterior root of the medial meniscus lies anteriorly to the anterior root of the lateral meniscus posteriorly the roots are seen here and they are very much closely related to two structures the posterior cruciate ligament and the ligament of iris bug. Coming to normal cases where we'll scroll through images and see the normal appearance of the meniscal roots how they look in MRI in all the planes. Starting with the sagittal plane let's see how the normal meniscal root appears please concentrate on the menisci here specifically the meniscal roots this is the lateral most part we see the fibular head here this is the lateral meniscus the body region as we are going medially we see the anterior horn and the posterior horn of the lateral meniscus look at the articular cartilage seen so beautifully over here as we are progressing medially this is the area of the anterior root of the lateral meniscus this is the area of the posterior root of the lateral meniscus we see the ACL coming up we see the PCL coming just anterior to the tbl attachment of the PCL is the expected area where we are supposed to see the posterior root of the medial meniscus as we further scroll this area that is coming up this is the anterior root of the medial meniscus and this black structure over here is actually the inter meniscal connecting ligament connecting the two anterior horns the horns of the lateral and the medial meniscus as we progress further this is the area of the body of the medial meniscus coming to the coronal plane from anterior to posterior anterior most this structure here is the structure connecting the anterior horns of both the menisci the transverse meniscal ligament this is the medial meniscus this is the lateral meniscus this is the anterior root of the lateral meniscus this is the area we have seen the bodies of both the menisci gradually even posteriorly this is the area of the posterior roots this is the posterior root of the lateral meniscus this is the posterior root of the medial meniscus and this structure here is the PCL as we have already talked in anatomy this area is very closely associated with the PCL the posterior roots are very closely associated with the PCL attachment here lastly coming to the axial plane this is the femur the condyce can be seen we are gradually growing downwards this is the lateral condyce with the ACL in close association this is the medial condyce where the PCL is associated here here the PCL does show some signal changes as we go down this is the level where we are seeing the menisci the lateral meniscus has a smaller C as we've discussed and the medial meniscus has a wider C the transverse meniscal ligament can be seen here this is the area of the roots the root of the anterior root of the lateral meniscus anterior root of the medial meniscus this is the area of the posterior root of the lateral meniscus this is the area of the posterior root of the medial meniscus this structure here is the PCL again we are having a nice look at the C-shaped menisci in this plane which is the axial plane where the radial tears are seen best we'll see it very soon coming to some still images of areas where particular attention is needed this is the anterior transverse ligament connecting the anterior horns of the two menisci this is the anterior root of the lateral meniscus normally the roots have a mild striated appearance in comparison to the jet black signal intensity of the meniscus proper and should not be confused with the tear or degeneration otherwise a normal root itself looks like this this is the area of the body of the menisci this is the medial meniscus this is the lateral meniscus we see the medial collateral ligament here the lateral collateral ligaments here and more posteriorly this is the area of the roots so this is the area of the root the medial meniscus posterior root this is the lateral meniscus posterior root in close association with the PCL now coming to the sagittal this is the anterior horn of the lateral meniscus this is the anterior root of the lateral meniscus posterior roots of the lateral meniscus this is the posterior root of the medial meniscus which is situated just anterior to the the PBL attachment of the PCL. We have to remember this, absence of this signal is called ghost sign that we see in posterior root of medial meniscus tail. And finally, the axial section shows us very nicely the C-shaped menisci here. This is the anterior, the transverse ligament connecting the anterior holes. This is the area of the posterior roots. This is the area of the anterior roots. Now coming to pathology proper. Now the spectrum of any MRI appearance of root pathology ranges from root degeneration to a partial tear or a complete tear. What are the main things that we should see in a root tear MRI are few in number. Number one, increased signal intensity or absence of meniscal tissue in one or two sagittal images where I have shown you is anterior to the PCL-TBL attachment. Why I am saying that? Because posterior root of medial meniscus tear is the commonest root tear. We also see abrupt blunting of the normal menisco-TBL attachment for shortened meniscus towards the posterior intercondyler notch. Meniscal extrusion, the meniscus has come out of its place and extruded out. Extrusion more than three millimeters is significant. In the axial section, we see radial tear in the region of the root and also we have to look at the surrounding areas to see the varying degree of cartilage damage, subchondral edema, subchondral arthritic changes, subchondral insufficiency fractures and TBL stress fractures. Tear is usually classified into four, incomplete root tear, complete with no gap or a gap of one to three millimeters or a big gap of four to six millimeters which should be mentioned in our report. Now, coming to my first case with some findings, specifically concentrate on the root, but I will tell you the associated findings also. Lateral most section, the body of the lateral meniscus shows some intra-substance signal changes. As we go medially, we see intra-substance signal changes in the anterior horn, posterior horn looks fine. The anterior root is hardly seen, so this could represent an anterior root tear. As we go medially, the ACL shows mucoid degeneration. There are some introscience ganglion cysts here. Some amount of edema is coming up. The PCL is coming up, jet black. Look at the difference in the signal between the two structures. As we go medially, we are expecting to see the posterior horn of the medial meniscus here, but are we seeing it? No, it is absent here. There is no posterior horn of the medial meniscus seen. It is still not seen. Finally, we see meniscal tissue coming here. And look at the amount of subchondral bone edema and the absence of particular cartilage here. The cartilage is supposed to be as nicely seen as this area, but it is completely denuded here. Finally, this is the body of the medial meniscus. Coming to the coronal view, from anterior to posterior, we see the connecting ligament, connecting the anterior horns of both the menisci. This is the medial aspect. This is lateral aspect. Lot of signal changes in the anterior horn of the lateral meniscus. As we go further posteriorly, we suddenly see four shortened posterior horn. The posterior root attachment is completely gone. There is PD-hyper intense signal over here. And the rest of the posterior horn is also showing significant signal changes here. There is a lot of subchondral edema also. So this is a posterior horn, posterior medial meniscal root tear seen beautifully in the coronal plane. As we have discussed, the MRI appearance is before. This is one of the characteristic findings we see in posterior root tears of medial meniscus. Coming to the axial section, axial plane of the same case. This is the level of the femur. This is the muquite degeneration of the ACL. We've already seen the jet black signal of the PCL. Coming to the area of the menisci of the same case. This is the lateral meniscus. This is the medial meniscus. We see the signal changes in the anterior horn of the lateral meniscus involving the anterior root. And what do we see here? We see absent meniscal tissue here at the level of the posterior root of the medial meniscus. See how beautifully it is seen in the axial plane. Absence of meniscal tissue in this area of the posterior root of the medial meniscus. This is the posterior cruciate ligament. Again, see how this C is suddenly getting disrupted over here through and through a radial tear over here of the posterior root of the medial meniscus. Coming to some still images of the case that I just showed you scrolling through all of them. This is the area of the subconral bone edema in the medial tbl condyne. This is the medial meniscus which is somewhat extruded out where it's supposed to be. It's come out of that area. And this is the absence of the root. Absence of the connecting tissue of the posterior horn into the pibia. This is the area where we are seeing PD hyper intense signal change suggestive of a posterior root tear. In this case, this is a case where we are seeing no tissue at all connected to the pibia. This is the axial plane where we are seeing the root tear over here, a radial tear in the region of the root. This is an example of signal change in the posterior horn which is extending into the root. We are seeing that the root is intact with signal change extending into the root. This is actually oblique horizontal tear of the posterior horn which is extending into the root. The cartilage loss associated that we saw in the previous sequences can be very nicely assessed in the PD non-faxat sequence. This is the cartilage signal which is supposed to be here throughout but is absent here. This is a case where there is meniscal extrusion with the meniscus extruded out. This gap has to be more than 3 millimeters to call it significant. There is some subconvial edema and here also we see absence of cartilage in the medial femoral condyne weight bearing surface. This is also a case of posterior root tear but we see some amount of residual menisco tibial tissue here following which we see the gap. So the previous case we saw signal intensity change going right up to the tibial attachment but over here there is some amount of residual menisco tibial tissue here and the tear is just adjacent to it. Now let's come to a case where there is a meniscal root tear with some associated findings because of chronicity of the tear. Starting from lateral to medial the anterior and the posterior horns of the lateral meniscus as we go medially. The ACL is seen the PCL is seen just anterior to the tibial attachment of the PCL we expect to see the posterior root of the medial meniscus but it is absent here what is called the ghost sign. We still don't see posterior root of the medial meniscus and what do we see disproportionate edema of the medial femoral condyne. See this carefully there is disproportionate edema here and careful viewing shows a line here a subconvial line which is nothing but an insufficiency fracture because of abnormal weight bearing. This was previously called as sunk sponk many things but it is basically an insufficiency fracture subconvial fracture because of abnormal weight bearing because of this meniscal root tear which is existing for quite some time. Let's see how this looks in the next sequence that is the coronal view starting with the coronal viewing this is the medial aspect this is the lateral aspect we see disproportionate edema in the medial femoral condyne and this meniscus is somewhat out of its normal position this is called meniscal extrusion so we see an extruded meniscus and a lot of edema here a subconvial insufficiency line also can be somewhat made out over here as we go posteriorly what do we see foreshortened posterior horn of medial meniscus with absent meniscal root absent posterior medial meniscal root with complication of insufficiency fracture in the subconvial region as we have discussed earlier coming to the axial section of the same patient this is abnormal edema in the medial femoral condyne as we go down below to the level of the menisci here we see absent posterior root of the medial meniscus this is the pcl so in all the planes we saw how the posterior root tear looks like in a case in this case which is complicated by subconvial insufficiency fracture in the same patient let's see a PD non-faxat sequence to see the subconvial fracture line better from lateral to medial as we go medially this is the pcl this is the absent posterior root of the medial meniscus the absent root and part of the posterior horn of the medial meniscus look at the fracture line beautifully seen over here the subconvial fracture line in the same patient seen this being a non-faxat sequence the edema can't be seen nicely but the fracture line can be seen very nicely here so this gives us an idea of how to see all the sequences to get a final idea about the pathology details coming to the still images of the case that I showed this is the disproportionate bone edema in the medial femoral condyme this is the extruded medial meniscus with bulging out of the mcl signal changes in the meniscus that we saw more posteriorly we see absence of meniscal tissue over here the posterior root of medial meniscus is strong the same case on a PD non-faxat image shows the subconvial insufficiency line very well so this is one case that we see complicated posterior root tear with abnormal weight bearing resulting in insufficiency edema and a subconvial fracture line which was previously known as sponk but it's basically an insufficiency fracture because of abnormal weight bearing now we have seen an MRI classification of root tear there is a lapradi arthroscopic classification of root tear also which is based on morphological features type one there's a partial root tear type two there's a complete radial root tear type three there is a complete root tear along with a bucket handle component associated type four which is an oblique tear into the root attachment and lastly type five which is a root evolution with a part of the bone evolved out along with the root as I've told before the treatment option depends upon age of the patient profession the symptoms condition of the rest of the meniscus whether they are already regenerated or not condition of the cartilage whether there's a small cartilage defect or a very large cartilage defect subconvial arthritic changes subconvial insufficiency fractures and stress fractures depending on that the orthopedic surgeon tries to understand what should be the means whether it should be a non-operative treatment conservative or a partial menisectomy or various repair techniques one of them I will discuss that is a trans-stibial pull-out repair done in young patients with a root tear where the root is relatively healthy a few pictures this is what arthroscopically a root tear looks like and another picture of the root tear and this is after repair the root is repaired arthroscopically here a little about post-op appearance of trans-stibial pull-out technique of repair this is a case of repair of posterior horn of medial meniscus where the meniscus is torn root is attached by mercilin tape to the tibia a tibial tunnel is actually formed through which the mercilin tape goes in and finally attached to by a screw in the anterior aspect of the tibia the same case in a saturated image this is the fixed posterior root of the medial meniscus this is the mercilin tape through the tibia tunnel and this is the screw this is the meniscus which is repaired and the mercilin tape is actually one knot is tied here and the other is passed on through the tunnel and fixed as I showed you this signal after operation remains almost for two years and should not be commented in a different way this is the importance of knowing about MRI appearance of post-op cases so that our comment in the report is in the right fashion and does not give any misleading ideas to the patient this is the x-ray of that patient the radiograph showing the screw so finally I end my talk with a few take home messages meniscal root tear needs to be recognized to prevent subsequent osteoarthritic changes of the knee most of the root tears are actually not true root evulsions but complete radial tear at the posterior root posterior horn junction or a para root tear we have to comment about the condition of the meniscus whether the torn meniscus is quite healthy or not we have to talk about the adjacent articular cartilage subconvial changes that has an effect on disease progression more the subconvial edema the patient will take time to heal so this has to be explained this has to be given in a report associated tears of the same meniscus should not be missed especially peripheral ramp lesions if they are there should be mentioned because if it is not taken care of and the arthroscopic repair is done then it will be not beneficial for the outcome of the patient and radiologists should also have an idea about the post-op appearance of meniscal root repair so that they give a perfect report and thank you to all my dear youtube viewers