Hopefully this talk is coming up. I'm going to speak on my approach to patellar instability, and I got the excellent lead-up, both showing the anatomy. I have no relevant disclosures to this talk. So I'm not going to dwell on this slide, but this chart keeps changing, because 15, 17 years ago, actually when I finished my fellowship, we operated on very few of these. Now we're even considering operating on first-time dislocators, and certainly if a patient has a patellar chondral defect, or a large trochlear defect, we typically operate right away, and most of us think that you should be operating on these patients, and stabilizing their patella at the same time. And whether that's an MPFL, or a TTO, or a MQTFL, that's a little bit what we're going to talk about. And so, all the old operations for this surgery resulted in some pretty poor outcomes down the road. I think a Hauser was a pretty successful operation as far as stability, but as you can see on this merchant view, the patient had a unilateral Hauser, and he had a unilateral patellofemoral replacement, so not such a great outcome. So why am I interested? I blame it on female surgeon, more female patients, but the rest of the guys up here are not female. This is a neglected population, and many of them should have had surgery long before they met me, and many of them had the wrong surgery. And here you can see another example of incorrectly done MPFL, where the screw was placed in the femur quite anteriorly. So, Aaron Critch just came out with a study in arthroscopy, and there's a number of these rating scales now, but when you look at the patient's radiographs, and their MRI, you can pretty easily give them a score, which is then going to determine whether or not they're going to re-dislocate. And I think we've learned this a long time ago in shoulders, and we certainly know this for ACLs, but if a patient scores a four or five, they have an 80% chance of re-dislocation. And for these patients, we may want to now consider operating on the first-time dislocator. So, in all these patients, I get an MRI, we're at a cartilage injury, and then now, depending on the parameters, I counsel the patient and the family about their risk of re-dislocation, and we make the decision whether or not to proceed with a stabilization. Now, I say treat both the arthritis or the cartilage and the instability. So, an osteotomy is really important to align the patellofemoral joint, and if they already have pain or already have a cartilage defect, then I think it's imperative. The MPFL is for stability, and while Beth Schieffenstein did do that study, we don't have long-term data whether or not these patients develop arthritis. So, I think, as John mentioned at the beginning of his talk, it's really important to optimize patellar tracking, and an MPFL is not enough. So, in my hands, I use almost always a gracilis allograft. They're much easier to get than semitendinosus allografts. We do run out of those, at least at the Hospital for Special Surgery. I tend to all suture anchors in the patella rather than a larger anchor or a tunnel. I use a tunnel in the femur with an interference screw, and at least my order of events is I palpate the sulcus. I tend to use a very small incision, but I caution my fellows that this is not how they should start out. Then I check the isometry, and then I confirm it on fluoro. And as Dr. Pulkerson mentioned, fluoro can be misleading, so at least I think this is the best order to proceed. I do a lateral release at the time, at the beginning of the case, if I cannot evert the patella to neutral. And the most important part of that exam is that the patella needs to be centered before you try to evert the patella. So, where are we aiming for with this tunnel? Well, we're looking essentially at Schottel's point. So, we're aiming for this area, but again, if you start out with fluoro and then go backwards, I think you're much more likely to accept a non-isometric graft. And as John mentioned, if the MPFL is not in the right place, you can get severe destruction. You can get fractures, but this 20-year-old girl lost 30 to 40% of her patella and had to have a large allograft, and that is obviously suboptimal. As far as tibial tubercle osteotomy, we used to talk about a Q angle, and now we have pretty easily obtained measurements. And so, I don't superimpose these in practice. I just put my cursor on the tibial tubercle and set the measuring guide on, and then I scroll up to the center of the trochlear groove. And you can look at the most caudal image, because a lot of these patients are quite dysplastic. It makes it difficult to measure. So, a TTO realigns. I mean, this is a no-brainer. This patient could not have an MPFL. The patient needs an osteotomy. But I do think a lot of the errors I see, and I seem to be seeing a great deal of MPFL failures, is that a patient like this with severe dysplasia and malalignment should not have had an isolated MPFL. And in fact, this patient actually had an osteotomy. They just forgot the part where they moved the tubercle. So, they did an osteotomy in situ. So, we did a revision MPFL and a revision osteotomy. Sorry, this is going the wrong way. So, I would say to consider a TTO if the catom de champ is above 1.2. In this case, it was 1.4. You see no overlap between the patella and the trochlea. If the TTTG is above 15, I think you start considering it. And if a patient has significant trochlear dysplasia, so I think you put these all together and make a decision. Distillization, I think, is a very important operation. One of the things we worry about, though, is as we distillize, potentially posteriorizing the attachment of the patellar tendon. And so, at least in my hands, when I distillize, I always anter medialize at the same time. Here, just you can see a patient with significant du jour B trochlear dysplasia and a TTTG of 15, this patient should have an osteotomy. Pain, again, needs different surgery than instability. If there's maltracking or lateral wear, you may have a medial defect if you had a number of acute dislocations, but with this lateral tracking, you may have a lateral defect as well. You need to unload this, and I would say you need to fix the cartilage. Cartilage loss should be filled in. I think it's dealer's choice what you use these days. And I think, overall, more is better. Here, you can see a 29-year-old with a 15-year history of patellar instability and pain. I look at this image, and I think patellar femoral replacement, except she's 29. And so, this patient had had multiple surgeries, and you have to be really careful because these patients were miserable when they come in, but they'll be even more miserable if you over-medialize them. And then, what about trochleoplasty? Here, you can see a couple post-op images. This one, thanks to Jack Farr, not his patient. And here, you can see another trochleoplasty. And one of the issues that many of us have with trochleoplasty is that the patella doesn't, even if you get the trochlear groove looking good, and I would not say this looks good, the patella doesn't fit. And don't over-medialize. Here, you can see sclerosis from a medial tracking patella. And here, you can see severe baja from a patient who had an osteotomy, and they didn't move her right away. So, the rehab with these patients, at least in my hands, is fairly slow. We don't start physical therapy until four weeks. And, in summary, data shows that we can better predict recurrence. And I think, now, we should be more aggressive surgically because the alternative is bad. Thank you very much. Thank you.

patellar instability

surgical approaches

osteotomy

cartilage injuries

recurrence