Good afternoon and thank you very much for the invite and thank you Dave and Sabrina. My favorite surgery actually. So I get to talk about that in the next couple of minutes. I do have some disclosures. So this is basically the take home here. These are the things that I want to know when I'm doing patellofemoral surgery and I'm walking you through this step by step. So understanding the cause for the chondral defect and its symptoms, that's really the absolute key if you're doing patellofemoral surgery to try to do cartilage repairs. You need to understand is this an acute versus a more chronic overload type of injury. You need to understand if this is focal versus general because that influences what kind of graft you may use, for example, to fix a defect. You need to understand where in the patella it is located because that has implications whether you can treat this with a TTO, for example, alone or whether you actually have to address the articular cartilage. You need to also consider that the patellofemoral joint is often unstable and that needs to be addressed. You can't do cartilage repair without correcting the instability. The same thing with alignment. Just like it is important in the tibiofemoral joint, it is even more important in the patellofemoral joint. And then finally you will have to assess whether this is a joint that is osteoarthritic versus actually a chondral defect. And these are the elements that you basically go through. This is a classic orthopedic element. You need history, exam, imaging. And I would contend that you need a scope on most of these patients in order to assess and put the whole overall picture together. These are a couple of examples. So this is a very wide variety here. So you have a case here with a large chondral defect with a very dysplastic joint with a almost degenerative looking type lateral sublux defect on the trochlea. So this is a very complex case. And then you also see if you look in the subchondral bone, you have multiple features here. You have a small cyst here and then you have an edematous region. This is important to understand because if you have actual destruction of the subchondral bone, that changes what kind of implant you can use as opposed to just having simple edema. And then the final thing you see on the right in case you need to assess, for example, things like patella alta. You need to assess measures in order to understand what the actual magnitude of instability really is in this joint. This is another example. This is a lot more straightforward. This is a central defect in the patella. I have taken this out for you. Here it's relatively small, but in otherwise totally normally aligned joint, completely different story. And this is something, for example, where you can very simply just mostly address simply the actual defect without having to address too many other factors regarding instability or malalignment. You need to address a cause and fix a defect. So that means if you have malalignment, you need to address the malalignment with the TTDG. You may have to look at things like trochlea entry bumps. You have to address patella alta. With respect to instability, you need to check out your MPFL, your trochlear dysplasia. And with respect to the chondral defects, you need to have an armamentarium of different techniques available. You need to be comfortable doing OCAs, doing MACI, potentially the good old OATS techniques or the PJAG techniques. You also need to understand the subchondral bone, as I mentioned earlier, because that influences if you are going to be likely successful with cell-based procedures versus needing osteochondral allografts. And there's no clear-cut lines here. A lot of that really is an overall picture that you put together. And don't forget, you need multiple modalities to often assess that. Not in everybody, but in a lot of these patients, you may require CTs and MRIs, as well as dynamic CT scans, occasionally even bone scans. And you may have to look at valgus alignment. You may have to look at rotational alignment. So this can become very complicated very quickly. And you need to understand whether you need to go into that direction or whether this is a more straightforward, simple case. What that requires is that you actually have a fairly standard algorithm of measures that you work the patient through and examination points that you work the patient through. So look at the different factors that influence your lateralization of your patella, your dynamic alignment. You need to assess all these things and scrutinize your strategy. Always double-check your tubercle position. Maybe use even two measures for each. Scrutinize your NPFL. And then when you are doing chondral implants, do not use unproven technology. The patellofemoral joint is more unforgiving than the tibiofemoral joint. You just heard that from Jay Ebert, even in the long-term outcomes. This is not the place to use stuff where you don't know how it works. And finally, you need to understand rehab and recovery. You need to, up front, set expectations. These are not patients that are going to go back to high-level, high-impact sports. You need to understand the muscle activation before and after the surgery. And newer technologies such as BFRT here are absolute game-changing in that respect. You need to also understand and be very vigilant with your range of motion early after surgery. And don't be afraid. If they do get stiff, some of them do, and all of us have these patients, it's okay to do a manipulation. This is not uncommon. And then finally, you need to teach the patients that even after about a year, there will still be certain elements where they are not going to be perfectly normal. So you need to understand and teach them how to not overdo it. Respect the PROs. The PROs are very clear. They tell you that about 80% of your patients reach about 80% of a normal knee. Communicate that up front. We heard yesterday in our Future Speakers series, it is important to set expectations up front and tell your patients what they can expect. So I was asked for an algorithm. This is the best I can come up with. Understand the cause, understand the defect, address the abnormalities, and manage the expectation, teach to understand. Thank you.

patellofemoral surgery

chondral defect

joint instability

cartilage repair

patient evaluation