Name:
Discoid Meniscus
Description:
Discoid Meniscus
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Duration:
T00H10M34S
Embed URL:
https://stream.cadmore.media/player/ec213e36-610c-4387-920f-bcfeb89390a6
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/ec213e36-610c-4387-920f-bcfeb89390a6/Discoid VuMedi.mp4?sv=2019-02-02&sr=c&sig=eVOqs6GPQGXmj5v6C4m7wLHXKJeby2DoKkmPeBhx134%3D&st=2024-11-23T10%3A49%3A53Z&se=2024-11-23T12%3A54%3A53Z&sp=r
Upload Date:
2024-05-31T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
NICHOLAS COLYVAS: Hi, I'm Dr. Nicholas Colyvas from UCSF and I'm presenting a discussion today on the Discoid Meniscus. We'll have a case example, a video repair technique, and a discussion about this interesting meniscus variant. The case example is a 23-year-old female. She's active, she loves to play tennis, garden and walking. And she sustained a mild twisting injury to the right knee approximately six weeks prior to presentation in our office.
NICHOLAS COLYVAS: She had lateral pain with some mechanical symptoms there, specifically a clicking sensation, and on examination she had positive meniscus signs with a tender lateral joint line and positive meniscus tests. She also had a distinct clicking sensation on palpation of the lateral joint line with range of motion testing. The range of motion was normal compared to the opposite knee, and both stability and line alignment in this knee was normal. On X-ray,
NICHOLAS COLYVAS: she had the classic discoid findings that oftentimes show up in the OIT exam. This specifically is a flattening of the condyle as well as a widening of the joint space, particularly in comparison to the medial side, and actually this is present on both sides in her case. The MRI examination classically showed a discoid meniscus, which is by definition three cuts at five millimeters, showing continuous lateral meniscus,
NICHOLAS COLYVAS: and this coronal view also shows that a lot of these meniscus do have a horizontal cleavage component here with even a small cyst associated with it. So this is not a normal meniscus by the typical criteria. The sagittal also shows that microcystic formation and further the horizontal cleavage nature of these types of tears. And in this case, it appears that she also has a clear radial component, which you can see on the axial
NICHOLAS COLYVAS: if the cut is correct. This is probably acute feature of a discoid meniscus that is likely been present since birth but is now symptomatic due to this tear. We also obtained T1 rho images on these patients, and they show the acute change in the cartilage stress patterns that you see in red here that are indicative of some kind of an injury that is causing increased contact stress on that cartilage surface.
NICHOLAS COLYVAS: So discoid meniscus essentially is a meniscus that is not fully formed and continues to have a flat and complete or sometimes incomplete coverage of the tibial plateau. The Watanabe classification is the most commonly used. They're present in approximately 3% to 5% of the population, and it's typically the lateral meniscus. The medial meniscus is described as approximately 80 cases in the literature.
NICHOLAS COLYVAS: It's exceedingly rare, particularly in comparison to the lateral meniscus, discoid meniscus and these are approximately 25% of these are bilateral. The diagnosis can be suspected on the radiographs, as we pointed out earlier, with squaring and flattening of the lateral condyle and some cupping of the lateral tibial plateau as well, a widening of that lateral joint space.
NICHOLAS COLYVAS: And the MRI shows, typically shows these discoid meniscus very well. Again, the criteria is 3 or more 5 millimeter sagittal images with meniscal continuity. Generally these, if they're picked up incidentally, are not symptomatic, do not require surgery and are treated with observation. Those that either have an acute tear or become symptomatic can be managed conservatively for the most part
NICHOLAS COLYVAS: but cases resistant to conservative management or with significant mechanical symptoms oftentimes will need surgery. The surgery itself. At the time of surgery for this case, we entered the lateral compartment and here with range of motion testing could see a pretty obvious mechanical subluxation of that anterior horn of the meniscus, which was causing those mechanical symptoms.
NICHOLAS COLYVAS: And this is the classic look of these discoids with the meniscus tissue all the way up to the notch. In this one, further examination and probing shows this radial tear and essentially a deeply unstable meniscus. We start by saucerisation, in other words, debridement of the meniscus, taking it back to something that resembles the appearance of a normal meniscal rim.
NICHOLAS COLYVAS: This involves using a biter and a shaver and once you do that, what you'll often find is this horizontal cleavage that you can see from the MRI originally that is now what you're left with. Once you've saucerised these. So if we see that, see and in this case, we had done some of this resection and saucerisation and still had this unstable meniscus, which we felt was due to the continued presence of a little excess anterior horn.
NICHOLAS COLYVAS: And this obviously we didn't want to leave that way so proceeded to resect further anterior horn here. We found that the biter was not that effective so in this case, we switched this technique, switching to a knife, getting to the apex of the tear there and taking out that additional anterior horn tissue, which clearly was catching and impinging and taking out a fair amount of anterior horn here
NICHOLAS COLYVAS: so that tried, attempted to restore the normal mechanics. So once the knife is used, you can clean up the excess with a shaver and a biter, get that piece out, make that meniscus look a little bit more normal. And now you take that through a range of motion again, test, always test these and you can see that now that meniscus mobility is more normal.
NICHOLAS COLYVAS: Again, we now go to repairing that horizontal cleavage tear. We use a shaver, we oftentimes use a spinal needle and trephinate it here, try and get some bleeding and encourage some healing from these tissues. And then we use a circumferential device. You can use a number of different types of these devices, but essentially we zip this closed, a number of sutures, circumferential sutures here.
NICHOLAS COLYVAS: This is 2.0 suture. This works very well. Try and push the knot towards the back and it's important to use a good number of sutures here, not just a few. You have to really space these three to five millimeters apart. The same technique every time. One, one pearl here is to use a passport, use a cannula of some sort
NICHOLAS COLYVAS: so that you can move this, place these sutures here without bringing tissue bridges along the way and just keep going here. Again, the more sutures, typically, the better here to close this up and zip it, zip it, zip this up completely. Once you're done, you should have now a construct that has a good number of sutures is tightly closed and resembles the shape, at least of a normal lateral meniscus here.
NICHOLAS COLYVAS: Once you can probe it and make sure that it's stable and that all of your sutures have closed down that horizontal cleavage component. Once you've done that, you can test it again for stability but at the end of the day, this is what these typically look like when you have completed your repair. As with all of our repairs, we definitely do some biological augmentation that can be PRP, that can be fibrin clot.
NICHOLAS COLYVAS: We particularly like bone marrow stimulation. I think the data there is reasonably good and that includes, that involves basically microfractures at the notch so that you can release some of that bone marrow substance into the knee. So our post op protocol for these are compressive type injuries and we have them with limited weight bearing for the first two weeks and then we can weight bear in extension after that.
NICHOLAS COLYVAS: And we limit flexion out to a total of six weeks. This patient, we were able to get an MRI at approximately a year later. You can see here that we've reconstituted now her normal meniscus with on the sagittal here. This looks like a normal meniscus. It's no longer connected and actually the meniscal quality looks pretty good as well.
NICHOLAS COLYVAS: Here it is on the coronal, again looking far more like a normal meniscus than the typical discoid would and the axial here you can see something resembling a normal meniscus, lateral meniscus shape again once we've completed this saucerisation repair. This patient has gone on to do well, no pain, returned to all of her activities and is happy with her knee.
NICHOLAS COLYVAS: Thank you again for your attention. Again, Dr. Colyvas presenting on discoid meniscus. Thank you. [VIDEO ENDS]
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