 Okay, so I am an orthopedic surgeon and orthopedic sports medicine is my subspecialty. So I take care of a wide range of patients, but younger patients with hip pain is one thing that I take care of a lot of patients for. And so that's sort of the theme for this talk is young and middle-aged patients with hip pain and femoroastabular impingement or FAI is probably the most common cause of hip pain in patients, in younger hip patients, patients who do not have hip arthritis. Certainly hip arthritis when we get older is more common, but in younger patients, FAI and labral tears are the most common thing. So that's sort of why I have a centered topic. I have no disclosures relevant. And I'll start with a case to sort of display a typical scenario that I see a lot and isn't very common. So a younger patient, a 26-year-old female with hip pain for years, no specific injury, gradual onset, the pain is anterior toward the groin, which is very common location for true hip pain from pain from intraarticular in the hip joint itself. And she has some clicking and her pain is worse with sitting, pivoting and impact exercise. And so that's a problem for her because she can't do her normal exercise. Her physical exam shows good flexion of the hip. She has limited internal rotation, only 10 degrees compared to 20 degrees in her other hip, but she has good strength. The fader test is adduction internal rotation test, which is a test that we commonly use to test for pain in the hip joint. And so she's positive there and many of the other tests are negative. We don't have to go into those right now. So there's three standard x-rays that I get for a patient with hip pain, the first of which is a AP pelvis. And so I have them do this standing, but this shows us both hips so we can compare. And in her, we see that she has, does my pointer show up? Yes. Okay, great. So it shows that there's good space in the joint, meaning she does not have arthritis and she's young anyways. But there's good space in both of her hips. Her right hip is the one that bothers her. A done 45 is rotating the hips slightly. And so this view is good for young people because this brings out what we call the CAM lesion, C-A-M, the CAM lesion. And so what that means is instead of the ball being rounded, like on the under surface, you see how it's rounded and it curves in. On the top, it just goes straight down. So this is abnormal bone. This is extra bone on the femur side. And this I'll explain more as we go, but this leads to impingement. And so this 45 done view is a good x-ray to get to look for this CAM lesion. And I get this in everyone. This is how you measure how much extra bone there is. It's something called the alpha angle. But the ball's supposed to be perfectly round. Bone that's sticking out outside the round ball, that's the abnormal bone. And then the false profile is the third view. So the three views are AP pelvis, a done 45, and a false profile. And this is rotating the pelvis. So this gives us a side view of the pelvis. So those are the three x-rays that are the best to get for younger people with hip pain. And this shows us the front of the socket. This is the front edge of the socket here. And this shows that she has normal anatomy of her hip socket. So from this, my diagnosis is femurous tabular impingement syndrome, which I'll break down further as we go into this. But this would be a common scenario. Someone young with some hip pain for a few years hasn't really had any treatment. And so we generally treat this conservatively first. So FAI and many things that get young people pain in the hip respond to physical therapy in general. And so we start treating this with physical therapy. Whether we need an MRI is up for debate. And we can talk about that as we go further. But in general, most young people that are having pain in the hip can be treated starting with physical therapy. They don't have to have an MRI. I would say, I'll say now and I'll say it again, one of the reasons to get an MRI in a young person is if you're worried about a stress fracture. And a stress fracture, a common scenario that you might see is someone that has recently picked up running or recently increased the amount that they run. And now they're getting pain that's associated with either the running or bearing weight. And those patients, you should get an MRI right away on. And the insurance company will authorize that always if you're ruling out a stress fracture. So that's a good reason to get an MRI. Otherwise, most things can wait on getting the MRI. So she had an MRI. And what it shows, this is the side view. This is the labrum, the black right here. This is a tear in the labrum. And this is a cyst in the bone. And this is caused by the impingement that we'll talk about more. Here's another view. This is what a labral tear looks like, this white line going into the labrum. The labrum is this triangle. And it's supposed to be all black. Here's it from the side views, or sorry, from the straight odd views. This is coronal. So here's the socket. Here's the femoral head. The labrum is black, but it's supposed to be a perfect black triangle. This gray that comes through here is the tear. And the only other thing the MRI shows you is a little cyst in the bone here on the ball side. And that's caused by the impingement as well. So she didn't get better with physical therapy. She wanted to avoid surgery. So she tried an injection as well. And that helped, but wore off in two to three weeks. And she kept doing therapy. And eventually, she couldn't get to the point where she wanted, so she chose to have surgery. And this is what hip surgery looks like arthroscopically. So this is putting the camera inside the hip. So this is the ball, femoral head on this side. The socket's on this side. This is the labrum. And this is abnormal because you're supposed to be able to see inside between the ball and socket here. This is, we pull traction on the leg to make space between the femoral head and the acetabulum here. And so you're supposed to see the space. This labrum is torn, it is falling down off the labrum and is in between. And so that tells us that this whole labrum is unstable. So this is what it looks like when you repair the labrum. So if you compare this top left picture to the bottom middle picture, this is what it's supposed to look like. This is after I repaired it. The labrum is supposed to be right on the edge of the socket. And so you can see how dramatically it was all separated and off the bone. And so I've repaired back to the bone there. There's another view of it. And then this is when we let go of the leg so we're not pulling traction anymore. And so the ball goes right back into the socket and the labrum forms a nice seal. And then the other thing we do is I talked about this extra bump of bone. That's the cam lesion. We remove this bone. And so this is what it looks like. The top row is the arthroscopic pictures. And then at the same time, we do fluoroscopy to get X-ray views. And that's what it looks like before. And this is what it looks like after you remove that extra bump of bone so that the ball is round. So it looks like it curves in on the top just like it does on the bottom. And this is all the abnormal bone that we remove with the burr to make it smooth down and so that it's round so it doesn't impact. And then this is just closing the ligaments to get into the hip. You have to cut through the ligaments to get in and stitch the ligaments back up together on the way out. And that's what it looks like after. See, you can compare her hip that we've now fixed to her up is not stigmatic, but she has the same cam lesion bone. But this is what it's supposed to look like, yeah. And so in general, these people are on touches for two weeks or three months. They start running and at six months they get back to playing sports. So the surgery is some recovery, but it is minimally invasive and arthroscopic. So it's not very painful surgery, but it does take time to fully recover to go back to playing sports and being a young active person. So here's the objective for today would be to recognize the sources of pre-arthritic hip pain. So hip pain in younger patients that don't have arthritis yet, which imaging to get, I've gone through the x-rays and we'll cover more. But those x-ray views that we wanna get in young patients, labral tears are very common. We're gonna talk more about that, but there are, it's caused by something and there's multiple things that can cause it. So you wanna know why the person has a labral tear. And then we're gonna talk mostly about femurous to have an impingement syndrome or FAI. So in general, when a young patient comes in with hip pain, this is sort of how I do my difference. So when I sort of do it based on the location of pain because location of pain in the hip is pretty good at pointing you to what the problem is. So I divide it into groin or pain in the front of the hip, on the side of the hip or in the back. And so groin or anterior pain is the most common thing. So I'll say that FAI is the most common and labral tears. Now, of course, hip flexor strenghens are common in resolve with time. Snapping hip is when the hip flexor is snapping over the hip. Displasia, so hip dysplasia, which we know about when babies have a dysplasia. But as people get older, not everyone's dysplasia were picked up when we were kids. So dysplasia meaning a shallow socket. Instead of a normal, curved socket, the socket's shallow. And so the ball can move around more in the hip. And micro instability is a newer diagnosis that we're learning more and more about by the day. It's a low level of sort of dysplasia to some effect. Arthritis, of course, is common in older patients and is in the front. Sports hernias, which we now call poor muscle injuries, are common as well. And then lateral, so out on the side, most commonly around the greater trochanter. You can palpate the bone on the side of your hip there. So FAI sometimes gives you pain on the side. But slightly less common. More common are things related to the greater trochanter there, which we now have lumped into the term called greater trochanteric pain syndrome. It used to be thought that it was just bursitis on the side of the hip. It's the other kids that that's not really true. It's not just bursitis. I'm watching a lecture now. Usually. No, okay. Maybe later. Could you please mute your line? It's usually somewhere on a spectrum, bursitis may be there, but that may be the smallest factor and the least common. The reality is it's more related to the gluteus medius tendon and gluteus minimus attaching to the greater trochanter. And tendinopathy there seems to be truly, when you look at the basic science of that area, that's really where the issues are. And it's a spectrum of just tendinopathy, partial tears of the gluteus medius and even full thickness tears of the gluteus medius. We now call the gluteus tendinopathy the rotator cuff of the hip because they really do have a very important role. And now we recognize more and more when there's tears there. An external snapping hip can happen on the side. That's when the iliotibial band snaps over the greater trochanter. Posterior, the most common thing is usually related to the spine, whether that's the lumbar spine or the sacroiliac joints, SI joints. That's common posteriorly. Now many people come in saying they pain the hip and it's really toward the back of the hip. And so greater trochanteric pain syndrome again, more commonly on the lateral side, but sometimes people feel that pain in the posterior. And there's a few other less common things which are deep gluteal space and ischiofemeral and it's outside the scope to talk about these other things, but there are less common things that can give people pain in the hip posteriorly. But here's sort of the most common. And this is how I deal with it and how I try to figure out what's going on in the hip. Because the hip's one of the things where the physical exam, the history are really important in it and it can be hard to figure out what's going on in the hip. Many of these patients have seen multiple providers before they get to me or someone else like me who specializes in this, because it can be hard. It's hard to figure out sometimes what's causing the pain. So we'll go into the labor more. So the labrum is a ring that goes around the edge of the socket. So this green is sort of the cartilage in the hip and the rim around it is where the labrum. You can see the labrum is a triangle that extends from the edge of the acetabulin and it's indirect continuity with the cartilage. So in this view, this is with the femoral head removed. It's a horseshoe shaped. There's a ligament called the transverse acetabular ligament that connects it at the bottom. But in cross-section it's triangular. So here it's one of the earlier microscopic studies which the studies on everything about the hip are actually not very old. This is 2001. So most of the research in this is in the last 20 years. But the labrum is triangular. This is the articular cartilage. It forms its direct continuity with the labrum. And the joint, this is the joint side, the femoral that would be here. This is fibrocartilage that is in direct continuity with the hyaline cartilage of the hip. And the important thing is that there's sensory nerve fibers in the labrum. So when there's a tear in the labrum, when it actually develops, there are nerve endings. So that's why people can't have pain from a tear at it. Unlike the articular cartilage, there's no nerve fibers there. And so when they have pain related to the cartilage, it's usually pain related to the underlying bone. So here's another view of it. And the role of the labrum, the more research into it, the more we know. And it gives you a little more surface area because it extends the cartilage out. So it gives you more surface area for the ball to move inside the socket. It also forms a suction. So the hip is actually on suction and there's negative pressure in the joint. So the labrum forms a seal to keep the fluid. There's about a milliliter of fluid in the joint and that labrum keeps a suction to keep the fluid in the joint. And it maintains the negative pressure in the joint which is important for stability in the hip. We think that the hip is innately stable because it's a ball and socket. The reality is there is microscopic motion of the hip and too much can be pathologic. So the labrum is important in that stability role and maintaining the negative pressure in the hip. So we know that tears in the labrum happen for specific reasons. And the first study that looked at this in 2004, 90% of patients had a bony abnormality for the tear. So these are people that had confirmed labral tears on surgery, 90% of them had a bony abnormality. And so it can be from different things. FAI, which I'm gonna go into more to really describe it and explain it, but other things, so dislocation. So the hip dislocating completely out of the socket which happens from a big injury, a car crash or something high energy in a sports injury. When the hip dislocates, it can tear the labrum, no question. Displasia meaning the socket's too shallow instead of it being a nice curved socket, it's too shallow, meaning the ball's moving around too much in there. That extra motion can tear the labrum. And then now more recently in the last five years, probably we've learned more about microincibility. So just microscopic extra motion in the hip can give you more susceptibility to a tear. And something like Illar's Danlos Syndrome where people are ligamentously lax may get this more commonly. So they're real flexible in general and it may give them more motion in the hip. So this is what FAI is. So this was the first picture that everyone references for when FAI was sort of described. So on the left is the cam. So the cam is the extra bump of bone here. So instead of it curving in, it sort of sticks out and goes straighter down. And so this is abnormal bone. So when the hip flexes up, that extra bone hits the edge of the acetabulum, the edge of the socket and it hits the labrum. Here's the triangular labrum at the edge of the acetabulum and it pinches that area. And you can see that it hits the labrum but it also hits the cartilage. So the problem here is it causes a tear in between the cartilage and the labrum. And I just said that the labrum provides a seal to keep this all in continuity. So when you disrupt between the cartilage and the labrum, you lose that seal. And so that potentially is a big problem for the hip. Pinsar impingement is the other kinds. There's two kinds of FAI, cam and pincer. So cam is more common. Pinsar means that the socket sticks down more. I'll show you some pictures. So instead of, you can see where the socket ends, normal. This would be the socket sticking down more. And the problem with that is when the hip comes up, there's no extra bone on the ball side. So it actually hits down on the femoral neck, hits that extra bump of bone. And the classic issue here is that you get injury to the cartilage on the opposite side because it's levering on the neck here. Now this clearly is gonna injure the labrum as well but you can also get cartilage on the opposite side that's injured. And so here's a typical cam lesion. So instead of the ball curving in, it sort of sticks out here. And this patient, they have it on both sides which is very common in people that were athletes when they're young. I'll tell you why soon. And here's pincer. So pincer means the socket sticks down too far. So it sticks out to the side more and sticks down more. Now this person has both. They have a cam. You can see how this comes down instead of curving in. And so they have both. So you can imagine you'd really get these two bumping into each other early on when the hip is flexed. Displasia, which I've mentioned means the socket's too shallow. So here you can see that the socket doesn't curve down at all. It actually is sloping upward. The other thing that you notice about this is that more of the ball is sticking outside the socket. And so that means this femoral head is gonna move around much more in the socket than otherwise. And so this is a big problem. This leads to rapid arthritis. And the treatment for this is actually an osteotomy of the pelvis, cutting through the bones of the pelvis and reorienting the socket so that it sticks down more and so that it covers up the head to keep the femoral head in the socket. And these patients, if this is not treated, this turns into arthritis as early as late 20s. And so dysplasia can be a disaster much more so than FAI or impingement and all these other things. So this is the one, when we see this, we know this needs to be treated. The surgery for this to correct the socket can actually dramatically change the natural history of this disease. And this can delay a person from, instead of getting arthritis when they're 31 years old and needing a hip replacement, they could potentially be delayed till their fifties, which is a huge change in a person's life. So that can be life altering for sure when we pick this up. This is a microinstability. This picture is showing the physical exam, so you bring this hip down into extension and rotate the leg inward. And that will give patients a feeling of apprehension or pain in the front of their hip, like the ball's gonna come out the front of the socket. But what microinstability is, is a subtle increase in the motion within the acetabulum. And it can be caused by different things. So dysplasia, if it's not truly the full on dysplasia and the socket's just a little shallow, they can have this. Connective tissue disorders like illers-danlos, you can get it as a result of injury where the ligaments of the hip get injured. We see this among ballet competitors and athletes. And so they will, because they're so flexible and because they stretch their hips on purpose, they can actually stretch their ligaments pretty extreme and can get instability. It happens iatrogenically from having surgery on the hip. When hip arthroscopy first came out 15 years ago and people were still figuring out exactly how to go about doing it the right way, we know that some people got instability in the hip from cutting through the ligaments of the hip to get inside and then not repairing them afterwards. And there's reasons we don't know. There is idiopathic cause. So here's the FAI again and here's how we measure it. And so the more this bone sticks outside the perfect circle, the bigger the cam lesion is. So it's at the femoral head neck junction and we have this alpha angle that we use to measure it. It's, sorry, it doesn't project great but the issue with that is they have less offset between the neck and the front of the femoral head. And so it's gonna cause earlier contact with the socket and the labor. And so we use the x-rays to try to get a three-dimensional picture of where this bone is sticking out. And so every x-ray angle shows us a different part. Now the cam lesion occurs enterolateral. So 12 o'clock up at the top here, this is the lateral edge of it. You know, here would be more anterior which is brought out by these rotated x-rays. And so those show us the more anterior lateral bone and that's where the cam lesion is. So that's the logic behind the x-rays. So how does this cam bone occur? And there's lots of evidence that points to this being a developmental thing. When the feces is open in children, this is the fecial scar, this white line right here. So this is the open growth plate in kid. And when kids are playing lots of sports or being very active, they put a lot of stress through this growth plate. And so the thought is that the bone that forms here abnormally like in the lower picture is formed by a reaction to the stress going through the growth plate. And that theory has really been brought out by lots of studies that have compared the sizes of cam lesions and whether there is a cam lesion or not in patients who are active growing up or not. And there's actually a market difference. People that played sports and were active when they were young have much, much higher incidence of having a cam lesion in general and also having a bigger cam lesion to the point of being 60 degrees, the average alpha angle in athletes and 47 and not and having a cam lesion 64% in kids that played sports young versus 40%. So it really does point to this being a developmental thing. So meaning FAI cannot be caused in someone who is still developing, still has open growth plates. They don't even have this abnormal bone yet. So this, the condition of FAI really starts in the later teens and most patients complain about pain in their 20s and 30s. Probably when it's repetitively caused enough damage to tear the labrum and cause some issues. Pinser can happen sort of two different ways. So I said pinser is where the socket sticks too much down the end. And so this shows what's called a crossover sign which means that the acetabulum is rotated. So the acetabulum supposed to put point anterior just barely, but actually in some patients everyone develops different. And you can have a retro version of the acetabulum meaning it's pointing more posteriorly. And what that results is in the front now the socket's sticking down because it's rotated toward the back. So these are some of the things that we look for on this. And you can have global pinser meaning the socket is just really deep. So the socket edge sticks out because the whole femoral head has pointed more medial. And these are more common in people as they get arthritis but these abnormal conditions like protrusion now the socket's really sticking out far. The pinser is slightly confusing for us and hard to figure out how best to treat because even though the socket has different shapes if surgically if we try to change the shape of the socket or remove bones so that you don't have a pinser and so that it's not causing impingement you can actually remove cartilage which would be bad because then you're changing the cartilage surface of the hip. We know in any joint if you remove cartilage you increase the stress on the rest of the cartilage in the hip. So this study did some 3D CT scan and really showed that even though the sockets were maybe retroverted or deep they didn't always have increased cartilage. The cartilage amount stayed the same until you got to this real dramatic pinser that was a protrusio. And so because of this study we've treated pinser lesions much less and less because we're worried about overloading the cartilage and causing people arthritis. So we're much more conservative in general about pinsers than we are CAM lesion. CAM lesions can be treated surgically much better. Either way with the impingement we generally treat people without surgery first. The other interesting thing about FAI and hip impingement is that many patients have these findings on X-ray or a labral tear on an MRI and they don't have any symptoms. So just because someone has a CAM lesion on an X-ray if they had an X-ray of their pelvis for some other reason and you saw a CAM lesion or you saw a pinser it doesn't automatically mean they have FAI. They may have no pain in their hip. This study looked at 2,000 patients that had X-rays that didn't have any pain in their hip and you can see in people that are athletic 55% of people had a CAM lesion. So just having the X-ray of a CAM lesion is not a problem. It's when patients are having pain and we think it's coming from the hip that it's an issue. Same with pinser. Pinser in the general population is really high, 70%. Pinser is a little harder because everyone measures it differently so we don't have as consistent a definition of it. We do have angles that we measure but people measure it differently. Labral tears on MRI are as high as 70%. So if a patient has an MRI with a labral tear it doesn't automatically mean they have an issue and it doesn't automatically mean they need surgery. Now, we're happy to see these patients and I always do, I see many patients with labral tears but they're doing just fine and it doesn't mean they have to have a surgery because they have a tear in the labrum. The reality is that probably the MRIs are just so good nowadays that you see things that are just not symptomatic and we don't operate on something that's not symptomatic. So just having the imaging findings is not a disaster. The problem with FAI is that it can lead to arthritis. Having FAI does not automatically mean the patient will get arthritis but it is one cause of hip arthritis. And we now know that this in the last 20 years this has been figured out that this is one reason why people get hip arthritis. Dr. Gans is the first person that figured this out and he's famous because of this and lots of stuff he's done around the hip. But he did lots of hip surgeries and he realized over time, he just started noticing that people with arthritis had these cam lesions and had these pincers and when he finally looked back at 600 surgeries he was able to publish this landmark study that showed it correlated with getting arthritis. And so it can cause arthritis but it doesn't automatically mean it will. And if it has started to cause arthritis the problem is we can't stop it then. So we know if we operate on patients that are already getting arthritis, we cannot stop that. So the tricky thing about all of this patients with hip pain that are young is we're trying to catch them with these issues that are causing them pain before it causes too much damage. If they don't have any pain, it's fine. We don't have any evidence to say they're gonna get arthritis but if they're having pain from this then it may lead to arthritis and if it leads to arthritis we then cannot do a surgery to preserve their hip. At least we don't have any evidence of that now. So in general, when patients already have cartilage damage or arthritis, it's likely too late to do a joint preserving surgery. Hip arthroscopy, minimally invasive arthroscopic surgery for the hip doesn't work when patients already have arthritis. We're trying to catch it before to make them feel better and potentially decrease their chance of arthritis down the road. We don't know that for sure but we think we can decrease it. So this is the algorithm. So because FAI and this cam and pincer is confusing you have to have three things to have FAI. You have to have symptoms of pain classically in the front of the hip near the groin. Many patients will have clicking or catching or the feeling of giving way. You have to have physical exam findings that either needs to be restricted internal rotation or pain with fader which is flexion, adduction, internal rotation. That's a classic physical exam. There's many other physical exams that you can do but honestly you really only need to check their internal rotation and the fader. And if they have pain that points to them having pain in the hip and it points the physical exam toward the pain that they're telling you about and then having the x-ray. So if you have all three then you have FAI. If you have two of the three then you don't. If you have one of the three you don't have FAI. So you have to have all three of those and that is the triad for FAI. Pain, physical exam and imaging. Now we can do diagnostic injections so injecting lidocaine into the hip to confirm that the pain is coming from in the hip and we do that when we can't tell for sure if the pain is coming from the hip and then we can get MRI and CT scans for other reasons. The MRI looks at other things. Soft tissue, the cartilage, it can tell us some other stuff about the hip but we don't need it for every patient. And then both operative and non-operative treatment are options for FAI. And in general we start non-operatively because it works for many patients and I take care of many patients every single day with FAI and the minority of them end up needing surgery. Most of them don't need surgery and it's the minority that end up do needing surgery. And that's arthroscopic minimally invasive surgery. We will repair the labrum and remove the extra bone. So here's what MRI can show you. So it's good at finding the labral tear which is right here, this white line going through. This is the labrum, that's the acetabulum. It can show you cartilage damage and subchondral edema. So this gray lines the cartilage and then you can say you sort of lose it here and you have white edema in the bone. So there's already some cartilage damage in this verse. Here's avascular necrosis which classically looks like this lesion right here. Every once in a while we'll find a tumor. So honestly, when we are getting MRIs, we are ruling out other things that could be causing pain. And every once in a while I will see a tumor. And then stress fracture. And this is the number one reason that anyone, if anyone's doing primary care and seeing patients with hip pain, if you're worried about a stress fracture, you should get that. And like I said, stress fracture usually happens in someone who's recently picked up running or has increased how much they're running. And then they have pain with weight bearing and pain with running to the point where they stop. And so this you should get an MRI right away because we can prevent this from turning into a true fracture. If we keep them off that, this will heal and they don't have to have surgery and they won't break their hip and you just have to get them off it right away. So stress fracture, when there's concern, we get MRI right away and you can get that improved from the insurance company every time. So the treatment, like I said, can be both nonoperative and operative. And in general, I treat everyone without surgery first for labral tears and FAI. And the reason that physical therapy works is because one of the problems with FAI is that the tilt of the pelvis changes when the impingement happens. So this study was very interesting. They did some sort of cadaver modeling of the pelvis moving and they showed that just if they tilt the pelvis 10 degrees anteriorly, it really changes the range of motion and it causes impingement much, much earlier in the motion. So tilt the pelvis 10 degrees anterior and you get 10 degrees less of hip flexion before that occurs. And that's actually pretty significant. 10 might not seem like a lot, but patients will notice that easy. And then five and eight degrees in limitations and internal rotation. And anyone in their 20s, 30s, 40s, 50s, they notice these differences and that they can't move their hip as well. So physical therapy can change your pelvic tilt and that can really increase their motion and stop the impingement from happening because the mechanics are better in the hip now. Just because the bone is there doesn't automatically mean it's gonna be a problem. You can have camel lesion, but if the mechanics are good, it may not impinge. Surgery for this works too, just to get an appreciation for this, 2008 and 2009 were when the first real studies of at least 100 patients came out for hip arthroscopy. So this has not been around for very long. And these were the early studies that showed hip arthroscopy works. Now in 2018, the biggest study yet, that's a meta analysis, looked at 31 reasonable articles that had a fair number of patients. And now we see that PROs, patient reported outcomes are improved in all of these studies. So the surgery does work. Repairing the labrum is what we wanna do, not debriefing it. You don't wanna just remove the torn labrum, you wanna repair it back down to the bone. And we know that we have low re-operation rates, only 5%, only 1% complication rate. So in general, it's pretty safe and pretty effective. 2019 with more sophisticated stuff where we look at the minimally clinically important difference. In this two year study, they showed 73% of patients had achieved a minimally clinically important difference. So the majority of patients are getting better. Now in this study, they had some patients with arthritis and things that we know are failure risks. And so if you eliminate, you can't eliminate workman's comp, but you can eliminate arthritis and BMI is questionable whether you can change that. And so the reality is if you decrease arthritis, you can get your rate of success even higher than that. And most people think it's probably 85 to 90% successful the surgery nowadays. So there's been three randomized controlled trials comparing surgery versus no surgery. One from the UK in 2018 published in Lancet, 170 patients in each group. At one year, they showed that surgery patients had improved more than without surgery. People improved in both groups, but it was the minimally clinically important difference advantage of surgery over no surgery, but both worked. And then in BMJ in published in 2019, just over 100 in the physical therapy group, non-operative treatment, both improved again. The PT in this did not improve that much. The surgery improved significantly more. So this one also favored surgery. And then the third and probably the worst study of all, only 40 patients in each group was done in the military here in the US and they had an issue with crossover. So 28 out of the 40 patients in the physical therapy group didn't do physical therapy and actually had surgery. So basically you had 68 out of the 80 patients in this study ended up having surgery and they found no difference between groups. But it's really not, this turned out to be not a great study. And in this, this is the only study in the literature where patients felt the same after the surgery. And so that sort of clued us in that there's something wrong with this study because there's been 31 other papers published to show the success of hyparthroscopy. So no one's sure why this turned out like this. And there's many theories because it was a specific patient population in the military that they don't know why this turned out. Returning to sports is great, about seven months to get back to playing the sports and 85% of patients can get back to playing the sports they want. Smaller study about running 94% of patients got back to running at eight and a half months. So it does take a little bit of time to recover from these, but people do recover. And then lastly, comparing males and females, which this is important to do in our studies because we don't know if there's innate differences in how people recover from surgery. This specifically looked at elite athletes, but regardless, the men and women returned back to sports at the same level. So that was also a good thing.