Hello, we're going to talk about different treatment options for osteochondritis dissecans. My disclosure is all up to date, and I have no relevant conflicts of interest. We'll talk a little bit about the difference between a stable and unstable OCD lesion and the importance of a healthy bone bed. We'll talk also about different fixation options for both bone and cartilage, and as well as different implant options and considerations as you think of treating these lesions. When I think of a stable OCD, I think of a minor apple bruise with intact skin, and these pretty much have very good healing potential. In contrast to this, an unstable injury, unstable OCD, is one in which there's a much more significant injury to the apple skin and the fruit, and the healing potential is much worse, like this example of an unstable OCD lesion. Indications for treatment. Non-healing stable OCD lesions may be treated with subcolonial bone drilling. An unstable OCD lesion, you probably need to ensure that the bed base is more healthy, not necrotic, and you may have to combine both subcolonial bone drilling with or without bone grafting and internal fixation. Indications about fixation. I think fixation, which you can save at least 60% to 100% of the lesion, by repairing it would be ideal. And you also want to make sure that the cartilage bone lesion is of adequate size and tissue quality to justify the fixation, and the tissue itself will hold this fixation. The ROC or throspy classification system looks at both stable and immobile categories, including the cue ball, shadow, wrinkle in the rug, as well as unstable or immobile lesions, such as a locked door, a trapped door, or crater-type lesion. For the stable lesions, these can frequently be treated with isolated subcolonial bone drilling, especially in those with significant growth remaining. In patients who may be older or closer or beyond skeletal maturity, you may need to consider drilling and fixation and possible bone grafting in some cases. For more advanced lesions, though, drilling and isolation is not going to be enough. The wrinkle in the rug category, in some cases, may be an unstable lesion, so fixation and potentially even bone grafting may be necessary, just like more advanced unstable or immobile lesions. There is a technique for drilling through the notch as well. So here's an example of the medial formal condyle that's already been drilled directly in a transarticular way. This is the PCL origin of the fibers, and this is a small video of how you can sort of drill off-center. You can actually come into the notch, and you can actually make some drilling right off the edge of the PCL, and actually hit a typical medial formal condyle OCD lesion by drilling, if you will, just outside of the articular cartilage margin through the PCL or through the inner condyle or notch area. So it's a nice supplemental drilling technique that you can use to make some additional drilling passes to help promote some subcondyle bone healing. There are different fixation options. There are metal options. We're well aware of these. They include headless compression screws, which are used for deep fixation. And there are some flathead profile screws, which can be used for superficial fixation. There are biabsorbable options, including pins, sutures, and anchor bridges, and also some screws. But I caution you about potential for reactions and cyst formation around some of these biabsorbable screws. When you think about headless screw fixation, you want to consider both the cartilage and bone. If you do have significant bone, you can countersink these screws into the bone and get excellent fixation. But if you don't have any bone, or you have very thin cartilage, these types of screws probably won't work. Even if you have very thin cartilage, or rather thin bone with cartilage, you may not get the fixation that you're looking for. A couple of things to consider that, once again, you want to countersink these into the bone, all the way into the bone, if possible. But there may be some screw fixations, options that work really well if the bone is healthy, but not so well if the bone isn't healthy. There are some non-screw options, including some press-fit devices and absorber devices you can consider as well. And these are examples. These are some biocomposite pins. And these can work pretty well in cases in which there's cartilage with no bone, or cartilage with minimum, as demonstrated in these drawings here. These bioabsorbable nails have been described, and have had pretty good success in some hands. If you're looking for another way to get fixation in minimal thickness cartilage, you can use low-profile headed screws. In these cases, once again, cartilage with no bone, or cartilage with very minimal bone. You can actually use a countersink to put these below the surface, but you have to be careful not to put them too deep, because you can cut right through and lose the quality of the fixation. Another option described by Ted Ganley and others is the use of suture bridge fixation, which may be a nice trick to have in your toolbox when you might need this in certain cases. Well, sub-colonial bone drilling, this is done typically for trans-articular drilling with a 0.05 inch, a 4-5 inch K-wire. You make drill holes about four to five millimeter intervals. Now, if you are looking at adding screw fixation, you can do this after you place these sub-colonial drill holes. And we'll just walk you through some examples of this. This here is a medial thermal condyle, and the yellow arrows sort of outline the OCD lesion on the medial thermal condyle. These are the previously placed sub-colonial drill holes done with a 0.05 inch Kirschner wire. And here's a guide pin for a cannulated screw system. And we're actually going to play a video here and just show an example of placing this threaded tip guide wire for a cannulated screw system. There's several good cannulated screw systems that exist on the market typically. And you see the blood coming out of one of those adjacent drill holes, which is a really good sign, because that suggests we've restored some vascularity of the lesion. Here's a measuring of the depth gauge to get an approximate size, typically 14, 16, 18, 22 millimeter lengths work for many of these cases. Here's drilling to create a path. You don't necessarily have to drill the full length of the screw, but certainly to get it started. And some of these drill guides also have a nice depth gauge on them as well, so you can sort of monitor the depth of drilling so that you don't remove your pin in preparation for placement of that screw. And after removal of the drill, the next step is to advance the screw. And here's an advancing of a screw with two different thread areas, one on the tip and one on the tail. They have differential thread pitches, so you actually get compression. So as you advance this screw further, you're going to see how this outer sleeve allows you to compress that OCD lesion firmly into the bed. And then you'll back off, at least in this type of design, you'll back off the outer. And now here's the inner star driver, and the star driver can be used to countersink and recess these screws nicely. So this is just kind of a nice close-up view as you're taking that down. You back it up, and you see it's still perhaps a little proud in the cartilage, so you're going to countersink it just a little bit further to make sure you're well below the subcontinal bone. You'll back the drill out here so you'll actually be able to see the screw buried into the bone, still ensuring good purchase. Once again, you want to make sure you've recessed these screws into the bone if you have adequate fixation because the quality of fixation will be better than fixation in the cartilage as well. Once again, you can palpate, probe these, but you want to make sure they're below that level of the cartilage and the subcontinal bone. I strongly recommend you use a star driver type brand because the quality of fixation and the risk of stripping is going to be less with a star driver as opposed to a six-sided or Allen head screw. After the screws are placed, I recommend you get multiple images just to make sure your screws really are where you think they are and they're adequately recessed in the subcontinal bone. And here's an example of healing progression of a patient who was treated with, here we are starting, here we are a month or so after the screws have been placed and subcontinal bone drilling is done, and at six months later, complete healing of that interface between the parent and progeny bone. As I mentioned before, you can use more superficial fixation options, and there are some different screws from 1.0 to 2.4 millimeter diameter length, and they're very low profile, kind of a pan head, not with a star driver, Allen driver, but with a cruciform head, and you can actually countersink these nicely because they're much lower profile than the screws, but I typically remove these at about four to six weeks just to make sure they don't fall back out and cause any other problems with counterfaced cartilage areas. And here's an example of a patella OCD delaminated lesion. The bone bed was drilled on the right, or excuse me, on the left. You can see the central lesion. There's the large OCD fragment with some bone on it, and then here are these countersunk screws that were used to engage adequate fixation and compression of this fragment. So cartilage and OCD fixation, fragment fixation is clearly possible. You want to make sure that you have a reasonably healthy bone bed to support this fixation, and the fixation options may depend a little bit on whether it's fixation bone or cartilage or both, and they're both metal, bioabsorbable, and suture fixation options that you consider.

osteochondritis dissecans

treatment options

subchondral bone drilling

internal fixation

screw fixation