What does that even mean? So we're going to talk about that a little bit, really in two entities. And so I think that Ashish and my other colleagues have talked really nicely about the kind of chronic things that can happen, but what about some of the acute things? So this is kind of a very famous video of Bo Jackson, where he had a subluxation of left hip there, went on to have one of the complications that we see with this, which is AVN requiring a total hip replacement. And so these are serious injuries. So what is hip instability in the case of traumatic instability? It's rare, but it can be devastating, as we saw there from Bo Jackson. It's typically associated with a fall on a flexed knee when the hip is flexed and adducted. And it's more often a subluxation than a true dislocation event. But you will see, and so we can talk through all of those things. What are some risk factors? We know that the radiographic appearance on the socket side can range from very deep, as you see there on the left-hand side of the screen, to more normal to dysplastic. Certainly, the more shallow the cup, the more likely they are to come out of it. We have this idea in our head about impingement hips and those issues of dynamic problems, as Ashish talked about, and then these instability factors. And they can both coexist. The epidemiology of sports-related traumatic hip dislocations, it's about 0.88 per million persons. 102 sport-related hip dislocations over a 10-year period was here. And the most common athletes to get injured with a hip dislocation are male football players. And so those are the ones that we really are going to kind of focus on a little bit. What are the risk factors for traumatic instability? Certainly, acetabular dysplasia. Having a shallow cup is a risk factor for it not being able to contain the ball very well. Acetabular retroversion, or turning back of the socket. If you're relatively posteriorly uncovered and you have a posterior directed force, you're more likely to dislocate. That you can see on the CT scan and with the presence of the crossover sign and a prominent ischial spine sign on that x-ray. Large cam deformities, secondary to a levering effect of where the hip hits in the front and is levered out the back. That can be seen. And so a lot of the male athletes that play football, they have this more significant morphologic characteristic. Ligamentous laxity. Patients that live farther on the spectrum. Things like Ehlers-Danlos syndrome or Marfan's. They're certainly at higher risk. Identifying these patients in your clinic with a Baden score. This is also going to be important for evaluation of the patients that have kind of this more micro-instability or these subluxation events secondary to a combined hip dysplasia and ligamentous instability. So what do you do? You put it back in. That's probably the most important thing. Get it back in as fast as you can. Certainly a dislocation event that's present for more than six hours carries a much higher risk of AVN. So it's really important to put it back in. On the field if you can. If you're unable to get it in on the field, get it back to the emergency department as fast as you can so that you can get sedation. There's a 20-fold increased risk of AVN if the dislocation is not reduced within six hours. So these are really one of the orthopedic emergencies. If you're unable to get it reduced, it may require an open reduction. That's fairly rare. And then what do you do afterwards? You get x-rays to confirm that you have a concentric reduction. And if you don't have a concentric reduction, what do you do? This is a really nice algorithmic way to think about it. So you have a suspected hip dislocation or a subluxation. You perform a closed reduction. You get a post-operative x-ray plus minus a CT scan. If there's a fracture, we'll talk through when those might need to be treated. You evaluate with an examiner anesthesia and then decide whether the size of the fragment or displacement of the fragment is enough to lead to fixation. If you have a concentric reduction, you can trial non-operative treatment for a period of about six weeks. Most people will do anywhere between four to six weeks of protected weight bearing. Some people advocate for getting an MRI scan at four to six weeks after treating this non-surgically. And then if there's increased signal consistent potentially with AVN, a follow-up MRI in three months. If they have a normal MRI at the four to six week post-op MRI scan, then they don't require further imaging and can get back to return to sport. If they have a non-concentric reduction, about 43.4% of patients that have a hip dislocation with a non-concentric reduction will have an incarcerated loose body. And it is often missed on a CT scan or a plain x-ray. So getting an MRI scan at that point. And then an arthroscopic assisted open reduction or other surgery may be necessary. So this is case one. This is a 21-year-old division one collegiate running back. Had an acute traumatic posterior right hip dislocation. He was reduced within one hour of the injury. And so risk factors for him certainly is retroverted. So his socket is uncovered posteriorly. Has some borderline dysplastic morphology. And also has a large CAM lesion as the potential risk factors for his dislocation. And so we got a CT scan. You can see here the three-dimensional reconstructions. You can see that there's kind of a sliver fracture of the posterior wall there. It is displaced to some degree. And so then the question is, what do we do with this? Is this someone that you can let heal? Is this someone that you should be fixing? And remember, when you have a posterior dislocation, it's not just the bone that's injured. Often the posterior capsular or the posterior labrum can also be injured. And those posterior capsular labral injuries, in addition to the bony displacement in this patient, led us to fix it. So he ended up having an ORIF of his posterior wall fragment with these two spring plates and another plate there that you can see. He also had a posterior capsular repair with a little bit of a plication and a posterior labral repair, all done through the open approach. And so this player has gone on to return to play football in Division I with no issues with his hip. There are some examples of patients that have been treated without surgery for these same kind of injuries. So what are the indications for thinking about doing an ORIF? Certainly any significant displacement of the fragment, anything more than about a millimeter. Any kind of secondary instability event. So if you choose to treat this without surgery and they have another instability event or a subluxation event, that's a time to get back in there. And then whether or not they have any evidence of retroversion. So if they're posteriorly uncovered and they will lose some of that posterior coverage even further because of the fracture, then you really want to think about being more aggressive with those. This is case number two. 17-year-old high-level competitive gymnast. This is really what Craig probably wants to talk about since we all love the hyper-flexible sports. Right hip pain after sustaining an injury while landing during an event. She felt a pop in her hip and had ongoing immediate pain. She did not require the emergency department for a reduction for a true dislocation. So this is more probably a subluxation episode. But now she presents after going through physical therapy with 7 out of 10 hip pain, both anterior, lateral, and posteriorly. She's used anti-inflammatories. She's modified her activities. On her x-rays you can see that she's got dysplastic morphology of her socket. She's got a pseudo-cam deformity with proximal flattening of the femoral head above the level of the physis with decreased femoral head-neck offset. And she has a labral tear on her MRI scan, more anteriorly than posteriorly. So arthroscopic considerations in this population, what's important for us is really good maintenance of the capsule. So this is somebody that you have to maintain capsular integrity because that is additive to their stability. In these patients, depending on how easy it is to pull the hip open at the time of surgery, you're going to want to probably maybe placate the capsule as part of their treatment. And then the question becomes also, do you perform a PAO on these patients? And so I think in our population, these borderline patients with instability episodes that can't get better without surgical intervention, very, very strongly should consider doing some kind of a stabilizing procedure. This is a technique that we developed on the right of the screen to perform mattress suture repairs of the capsule. So we pass the suture through the distal leaflet. We retrieve it through the proximal leaflet. And then we're going to pass it back through the proximal leaflet and retrieve it through the distal leaflet to be able to provide that kind of placation of that capsule here. So as we kind of pull it back out, it's still loaded into the passer here. We're going to pass it again through the proximal leaflet and then retrieve it through the distal leaflet, which allows us to really modulate how tightly we can close this capsule. And it's been a great way in our hands to be able to do this. And then obviously, on the other side, you just see a standard labral repair. So this patient was treated with concomitant PAO and hip arthroscopy for labral repair osteoplasty. Oftentimes, when you're doing a PAO, you also want to think about doing a decompression of the anterior inferior iliac spine and then a capsular placation. She returned to full participation in gymnastics with no residual symptoms above her prior level of participation at about six and a half months from surgery. So even if you add the PAO, it doesn't mean that these patients are going to be out for a year to 18 months. And these athletes that are more hypermobile, that are in the sports that require this hypermobility, dance, gymnastics, those kind of activities, cheerleading, these are the ones that you really want to have a low threshold for thinking about doing something from a bony perspective if they've proven themselves to be unstable as opposed to our first patient that had the fracture. Technical pearls, this is an arthroscopy where they had a fracture. They had kind of a displaced loose body. This is one that you can try and put back surgically because there is bone on the backside. If you can avoid the scope, it might be helpful because you can get fluid extravasation, which can lead to an abdominal compartment syndrome as it tracks up the retroperitoneum. You want to manage the capsule well as we discussed. You want to perform an excellent labral repair and be prepared to place anchors posteriorly in the setting of a posterior dislocation by utilizing a posterior lateral portal. And you want to avoid over-resection of CAM lesions proximally because that can lead to a loss of the conformity of the joint, which may lead to further instability. Why do we want to get this hip back in and why do we want to be active and aggressive with these injuries if needed? Because it can lead to post-traumatic arthritis. The big one is it can lead to AVN, heterotopic ossification, and some of these other issues like recurrent instability. So the main take-home points of this talk are that if the hip comes out, you've got to get it back in as fast as you can, certainly within six hours, ideally as soon as possible. And then looking for some of these risk factors for recurrent instability, young ligamentously lax females with shallow sockets or a displaced fragment in the posterior aspect of the cup. So thank you very much. Thank you.

hip instability

traumatic instability

Bo Jackson

acetabular dysplasia

avascular necrosis