Hi, everybody. I'm Seth Sherman from Stanford University, and I'm proud to be here at the Anna Advanced knee course. Andreas and Aaron have asked me to talk on first-time patella dislocation surgery or not. My disclosures are readily available online. First-time patella dislocations are an evolving and controversial topic, which makes it very stimulating and a lot of fun to engage as we learn more over time. The majority of these are sports-related, so if you have a pop and large swelling, it's really ACL, ACL, ACL, and then patella dislocation. You have to think about it every single time. These don't typically come in with x-rays that look like this. They often reduce spontaneously, and so if you're not thinking about it and looking for it, you won't know it's there. There's really not a consensus on early mobilization and weight bearing. Immobilizing inflection, while good in concept, is really impractical. They can get atrophy, stiffness, perhaps accelerated joint changes. I think most of us use early brace protection. Range of motion is tolerated. Weight bearing is tolerated with crutches. I tend to be fairly aggressive aspirating the hemarthrosis so that we don't lose the quad early. We want to evaluate for risk factors for recurrence, so we need to look at and measure what these are, really differentiating normal versus abnormal bony architecture. For the purposes of this particular talk, we're going to focus on a few key aspects. We've written and others have written laundry lists of things that we check really efficiently in clinical evaluations of every patellofemoral patient every single time, but we'll try to keep this straightforward. One thing we definitely need to look for is patella alta. I think the measurement we use on x-rays, as you see here, is the Catan de Champs. We can also use the patella trochlear index, as you see measured on that MRI. Trochlear dysplasia, very hot topic. For the purposes of decision-making in a first-time dislocator, we really want to know if there's presence of dysplasia or not. Get good at scrutinizing your lateral x-rays and your axial MRIs. You can see a normal trochlea up top to the left and a severely dysplastic trochlea with a crossing sign, supratrochlear spur, double contour. You can also see either flat, shallow, convex axial MRIs. Knowing whether it is or is not present is critical. Lateralized force vector, I think we all know about the clinical Q angle. You can see an example of that to the far right. We quantify this by the tibial-tubal trochlear distance or the TT-PCL distance. One or both of these measures can be helpful for a lateralized force vector. Patella tilt, we can see it clinically. We evaluate for it both on x-ray and CT or MRI. Those are the major ones. There are other patient-specific factors we think about like age, activity level, injury mechanism, specifically was it contact or non-contact, low energy, high energy. Do they have a personal history of other-sided dislocation? Do they have a family history of patella instability? All very important factors. We know the MPFL is the primary restraint to lateral translation of the patella from 0 to 30. It is torn essentially in every single one of these dislocation events. The location of that tear is variable. We have also learned from Dr. Paleta and others that there is a high incidence of chondral and osteochondral injury associated with patella dislocation, up to 70%. For me, and I think for the majority of us treating these patients often, we are trying to get good weight-bearing x-rays. I tend to get mechanical axis views when I can. I think this is changing to consider MRI for all first-time patella dislocators, not just for the loose bodies, but also for risk stratification in patients without loose bodies. I think we want to be very thoughtful about this. You can read my recent editorial commentary where I really lay out the rationale for risk stratification as the new standard of care. We really try to challenge that classic dogma that all first-time patella dislocators should be treated the same and that they should all be treated non-operatively unless there is a loose body or osteochondral fracture. It has been said that non-op treatment leads to universally good outcomes, but really when you deep dive into some more current literature, we see that that is not necessarily the fact. Non-operative, up to a quarter of them are without activity limitations, and 86% of those actually blame their patella for these problems. It is imperfect and it is not the panacea and not the answer for all patients. If you talk about recurrence rates, there is a high range from 17% to 71% recurrence in the different studies. I think that is one aspect also. When you look at cost-effectiveness, non-op treatment was the least costly, of course, but also the least effective. Immediate surgery and delayed surgery were both effective. Taking all these things with a grain of salt at least opens our eyes to consider risk stratification and operative treatment in some patients. If you have this 16-year-old female field hockey player, first-time non-contact dislocation, maybe she has a lot of the risk factors that we talked about. Is this patient the same as an NFL athlete who is a male, who is older, who has a contact injury, who may not have the underlying bony risk factors? Do we treat them the same? I would say just look to the shoulder literature in the evolution. Do we treat all shoulder instability and shoulder dislocations the same? Of course not. We know about tubs and ambry and everything in between. I think as we move in the patellofemoral space, we can borrow these concepts. This is a gross oversimplification, but I think it is useful. If you have that male contact athlete, high-energy injury, they have normal underlying anatomy perhaps, but they risk a significant osteochondral injury. They may present with a hemoarthrosis, which is different than the young female that twists low energy. They have abnormal anatomy that predisposes to dislocation. They may dislocate often with less swelling. That first group is at higher risk for an acute fracture that might need fixation, whereas the risk of an acute fracture might be lower in that low-energy patient. They have a much higher risk of recurrence. Those are some of the key points on both sides of the spectrum. I looked at my friends and colleagues at the International Patellofemoral Study Group for some guidance in this space. When you start looking at risk stratification papers, we see the variables we discussed about age, other side instability, dysplasia, patella alta, lateralized force vector, patella tilt. If you summate them in this study, if you have four or more of those, you have a 66 percent chance of recurrence. Another study here looking at similar risk factors, 88 percent chance of recurrence. Another study by Diane Daum at the Mayo Clinic, again, is looking and really summating, and she actually went as far to recommend surgical treatment for those with the 60 to 70 percent or above risk of recurrent instability. Our colleague Mario Havisi, also at the Mayo Clinic, created this RIP score that you can download to your iPhones. You can see if you have none of the risk factors, your risk of recurrence is zero percent. If you have some, it can go to 30 percent. If you have all, it can get upwards of 65 percent. I think with x-rays, MRI, clinical history, and risk stratification, we can really counsel our patients effectively about their relative risk. Now, obviously, recurrence risk is only one piece of the puzzle. If you treat them non-op, we know they can have a faster return. There's no surgical risk associated. If we do operate on them, there's clearly a higher surgical morbidity. There's a risk of early stiffness. There's a longer time frame to return. If we treat them non-op, is there progressive risk to the cartilage or ligaments? Are the functional outcomes, quality of life, return to sport as good? Things we need to learn. Is it better to treat them surgically as far as functional outcomes, quality of life, return to sport? Is surgery contour protective? I think we need these answers. Luckily, studies like the PAPI study, which is a randomized controlled study in this exact cohort, will help us. I think the JUPITER study, which is a multicenter prospective cohort study, will help us get these answers over time. Right now, there are more questions than answers. I would submit we need to just identify these high-risk patients. Those who have an opposite side that is normal, I'm really not quick to risk stratify and offer them surgery without loose bodies. I basically observe them carefully. If they have persistent apprehension or recurrence, then I might consider surgery. However, for those who've been through the ringer before on their other side, maybe they had recurrence, maybe they had a surgery, and now they're doing well. I'm more inclined to have that conversation about early surgical stabilization. Non-operative is core-to-floor rehabilitation and then functional progression. I think we want to be very diligent with these patients in critically evaluating return to sport testing before letting them back so we don't let them back too soon and they have a recurrence because they were not optimized. I think that would be a wasted opportunity and a shame. Is there a role for acute NPFL repair? Really not for me. Repair does not reduce those recurrence rates, so that's an important point. I rarely consider it. Perhaps if there's a fixable loose body and the patient has perfect underlying anatomy, super rare. Good or great tissue quality, pretty rare, and a distinct zone of injury, which can be challenging, then I might consider it. Really, for me, I don't have much of a role. Then when patients have all these risk factors we talked about, then there's really not any role for an acute repair because it'll just stretch out and it has a higher failure rate than NPFL reconstruction. Reconstruction is our workforce if we're going to do surgery. It reduces recurrence rate 35% to 0%. I would encourage you to learn how to do very standard NPFL reconstructions to avoid over-constrained and to use anatomical, biomechanical principles. There's no current role for me for bony surgery for a first-time patella dislocation. I worry about NPFL reconstruction isometry in those extreme cases, so when you have a very high patella or a very lateralized force vector, but that would be the exception and not the rule, so I'm not quick to offer TTOs and certainly not trochleoplasties or rotational osteotomies in these first-timers. I do consider guided growth in the skeletally mature, particularly those who are in valves. Clear indications for surgery, we know irreducible dislocations, large chondrolasty, chondral fractures, and loose bodies. Here's a patient who sheared off his entire lateral femoral condyle. We did internal fixation for him. We approached it through the lateral side and we did medial soft tissue stabilization with medial patella femoral ligament reconstruction, sparing the fices. Here's other examples where you can fix the cartilage-only shear, particularly in skeletally immature patients, so I'd encourage you to read this and consider this for the younger patients. I think now it's pretty much consensus that if we're going to fix a fragment of the septum instability after dislocation, we should stabilize the soft tissue to reduce the risk of recurrence. That means NPFL repair reconstruction, as discussed previously. Lastly, we have a really exciting patella femoral foundation online training course. You can see several of us have been involved in the project. I think many of the faculty at the course, the Anna course, are also involved. This will have whiteboards. This will have unique didactics and will be quite comprehensive, so I encourage you to look out for that at the upcoming Anna meeting. I thank you so much for your attention. Hopefully I've shown that the management of acute patella dislocation is evolving rapidly. We use MRIs for all first-time dislocators. However, most patients are still treated non-operatively. We offer surgery for patients with osteochondral loose bodies, both fixation and soft tissue stabilization, and then risk stratification to determine the risk profile in patients without loose bodies. I consider soft tissue stabilization in those high-risk individuals. I thank you very much for your attention, and I hope that you have an excellent course. I would have been there, but I just had a baby boy one week ago, and so I'm here at home changing diapers. Thank you very much.

patella dislocation surgery

sports-related injuries

x-rays

brace protection

recurrence risk factors