Hi, my name is Henry Ellis from Dallas, Texas. I work at Scottish Rite for Children's Sports Medicine. It is my pleasure to give a talk on pediatric and adolescent hip arthroscopy. My disclosures are listed in the Academy app. I have nothing to disclose that is pertinent to this talk. This is really not an unfamiliar graph. For those that are not used to taking care of pediatric patients, it's important to realize that really between the ages of 12 and 16, that there is a significant growth spurt in which there's a lot of developmental changes that can occur throughout the hip. So when caring for an adolescent patient with hip pain or hip impingement, it's important to have these considerations in mind. The big difference between the hip of a pediatric patient or even an adolescent patient is the fasciitis, the growth plate around the hip joint. As you can see here, the triradiate cartilage really closes somewhere between 12 and 14 years old, depending if you're a male or a female. The proximal femoral fasciitis really appears very, very young, but does not completely close until sometime later when you're 18 years old. And the greater trochopophysis is really the same thing, really appears very, very early, but doesn't close until late adolescence. The other big difference between kids and adults is the apophysis and apophysitis. So many of you will see apophyseal avulsions that will occur around the pelvis in this adolescent age group. So today we're going to review recent literature on hip arthroscopy for adolescents, discuss any differences between hip arthroscopy in an adult and a pediatric adolescent patient. We're going to just talk about the development of the CAM lesion, and it's very pertinent in the adolescent age group, and introduce indications for hip arthroscopic beyond impingement and labral pathology. When looking at arthroscopic treatment in FAI labral tears in the adolescent compared to the adults, really the prevalence is very similar. About 30% of adolescent patients have alpha amyls greater than 55 degrees when you're looking at an age group between 10 and 18. About 10% will have some sort of focal retroversion. And as expected in this age group, and as we see in the adults, the males tend to have higher CAM angles than females. When looking at the treatment for adolescent FAI, which is commonly part of the big picture when looking at hip arthroscopy, non-operative treatment has been advocated, not only by our colleagues in Boston, but as well as San Diego. Non-operative treatment can involve anything from physical therapy to activity modification to intra-articular injections. What's important with activity modification is that they continue to avoid the activity that causes the aggravating hip pain. Andy Pennock's article at Tears Outcomes showed that 82% had improvement and did not require hip arthroscopy. He's now in the process of publishing his five-year data, and we look forward to seeing that as well. As we see in the adolescent population, though, non-operative treatment and accurate diagnosis is really critical. Sometimes they may act like they have FAI or hip impingement-related pathology, but it really is extra-articulate manifestations of your hip flexor or even borderline hip impingement with micro-instability. As you can see here, arthroscopic treatment has been well discussed in the adolescent literature by several authors on several multisample trials. As adolescents get back to returning to playing sports, a majority reach clinically-significant improvement, MCID, with 76% achieving PASS. Up to 12% can require a revision. Revision arthroscopy, as described by Philippon, is a majority of the time because of some residual impingement or even some label deficiency, and we'll talk a little bit more about that later. In our experiences working with Dr. Philippon's adolescent patients, we looked at 64 patients. About 30% had open or transitional phthisis. About a fifth of them had some sort of traumatic onset, and you can see the mean alpha-angle is 64 degrees, which seems to be pretty typical with the adult population. We didn't see any complications at two years, and we did see significant improvement with their PROs. It was kind of interesting that Dr. Philippon then reported a 10-year outcome, so a much greater outcome. He looked at 70 hits with a mean follow-up of minimum follow-up of 10 years, mean follow-up of 12 years, 10% had revision arthroscopy, majority of revision arthroscopy was associated with global laxity, and those who presented with longer symptoms. As you can tell here on the graph on the right, all of those that did not undergo revision had significant improvements in their patient-reported outcome measures, their HOOS, their HRSA scores as well as their SF-12 scores. Some of my experience with FAI in adolescence, looking at our own series, we looked at 109 hits, 86 met our criteria, majority of which were females, average age around 16. As you can see, majority of which participated in sports, but not all of them, and we had roughly a two-year outcome on them. What you can see here is we had significant improvement in the patient-reported outcome measures, including the HRSA score, the HOOS, and the UCLA, but what was interesting is there was no correlation with the severity of their alpha angle or their lateral center edge angle with their preoperative symptoms, so this is saying the more symptoms they have did not correlate with the severity of the radiographic disease. Now this becomes pertinent because we did find a direct correlation between alpha angle and labral disease, not only grade of labral disease, but also length of tear, so the higher the alpha angle was irrelevant on the preoperative symptoms, but we did find it was directly correlated with the degree of labral pathology. This is really important because it means that the amount of pain and discomfort that they have doesn't always correlate with how bad their disease is in their hip, particularly in the adolescent patient. That may be why some of them present later on in life. We took a little bit closer look at the center edge angle, and we have currently pending publication. We looked at the lateral center edge angle, and we specifically looked at revision surgery, so total revision surgery in our series, both hip arthroscopy and open, was 11%. We found 46% needed revision surgery when we performed a hip preservation surgery when they had a center edge angle less than 21 degrees. We came up with that number using the rock curve that you can see there on the right, so there was a significant correlation between those that underwent a reoperation and a lower center edge angle, so I expressed some caution in the adolescent population. It's nice to know that the complications associated with hip arthroscopy in children and adolescents also have a very low rate of complications. This was reported by our colleagues at Boston Children's. So the most common question I get from other hip arthroscopists are, can adolescent imaging reoccur in kids? This study from HSS really showed that somewhere between zero and 20% of can lesions will regrow, some of which may require a revision surgery. What they noticed is those that were more skeletally immature had a higher rate of reoccurrence. Almost all of those that had recurrence of can lesion were skeletally immature compared to those that were skeletally mature. So the next question is, are all can lesions the same in young patients? As you can see here, there's a 12-year-old female soccer player. A nice lateral image, 45 degree down view, demonstrates a very low alpha angle with no significant femoral head and neck offset. When you look at the MRI, you've got to look at these really carefully because sometimes what you do is you'll see what I call soft can impingement in which the cortical surface of the femoral head and neck junction, which you can only see radiographically, is not representative of a potential can lesion. So this is a soft can lesion. You can see the adjacent labral disease associated in this adolescent patient. So we find that sometimes we do see these in the adolescent kids. You can see they have a thickened chondral surface. Also they can have a thickened perichondral ring that can cause this overgrowth. We'll talk a little bit more about that later. In our studies, we found about 10% of those that presented with femorositebral impingement had MRI evidence of a soft can lesion. This was out of 331 patients in which had MRIs at our institution. You can see the majority of which were female, they're about 16 years old, and a majority of which participated in sports. Our breakdown of what was the actual cause of the soft can lesion was periosteal thickening, but more commonly was a thickened perichondral ring that you can see in that middle image, and a few of which just had that fisial extension that created that soft can effect. When we actually looked at the x-rays versus the MRI, we found a significant increase in the alpha angle seen on MRI in adolescents, and it's about a 12 degree increase that you're seeing there. Some studies that have tried to correlate alpha angle and x-rays and MRIs have also demonstrated an MRI to have a higher alpha angle, but we think this is particularly true in the adolescent. So just because you have an x-ray that may be negative, be really critical of the MRI because that might show you a soft can lesion that's not present on the x-ray. We found in our series, we compared those that have that soft can and an osseous or really a normal can lesion, we found that they were fairly equivalent in terms of their overall outcome in the presentation, except those that had a soft can were just a little bit older. So what about preventing the development of the can lesion? This is a growth curve here, very common in pediatricians. You saw me show this image earlier, and what it really does is it really highlights the area of the growth spurt, and this is particularly important in the hip. Now, many of us know the Wolf's Law, Julius Wolf, founder and director of the Department of Geeks in Berlin. He of course stated that the bone in a healthy person or animal adapts to the load under which it's been placed. This is particularly pertinent in the growth plate. Now, Frost in 1979 adapted Wolf's Law and really looked at the rate of growth of the physis, and the rate of growth was based on the load present on the physis. In that, you would have an increase in growth of the physis with significant compression or repetitive overload that you can see here up into a certain point, and that may be why we see that development of that can lesion. This has been suggested by other authors. Siebenrock really was the first one to highlight this back in 2004, and when he looked at subjects, he really found that those that had can lesion have an extension of that physis off to the edge. Now, he then further supported this several years later, looking at the differences between basketball players and asymptomatic controls that did not play sports, and you can see here in this great example, those that play sports had a higher rate of can lesion, a three-fold increase in can lesions in those that played sports. Agricola, similar study. He followed these longitudinally, and you can see these were pre-professional soccer players, and you can see in the prepubescent phase, you don't see a can lesion, but in the transitional phase, you can start seeing that fysio scar go out towards that thermal neck, and these tend to only happen in young athletes. Philippon did a very similar study using youth ice hockey players over a three-year period, found that their average alpha angle increased while their aversion decreased, and the incidence of asymptomatic labral tears increased as well. Jeff Nepple did a systematic review, found that high-level males were two to eight times more likely to develop can lesions. You can see the prevalence of a can lesion athlete is 41% compared to 17% in the non-athlete. So what's really the punchline here? We need to continue to protect our athletes and form parents and really to develop a strategy. And although involvement at a high level of athletics is important, it is also important to consider that these periods of high-level activity during peak high velocity may cause the development of can lesion and further long-term detrimental effects to the hip. Looking at just some expanded indications in pediatric hip arthrosis, just some things to consider when you're dealing with younger kids, because you can see some things that are outside the box. PBNS, pigmented bilonodular synovitis, Cliff Wilmon has written about his series here. We do see this in kids. I see about one or two a year. Perthes disease. These are some of the happiest patients. Oftentimes, they have large chondroflaps, loose bodies, and there is an opportunity to perform an arthroscopic reshaping of that femoral head, but you've got to be really careful because they tend to have significant ivetabular deficiency. The utility in a subcapiformal epiphysis, depending on the severity, usually works really good in the symptomatic ones if they have a mild deformity. Those that have severe deformities, probably arthroscopy is not indicated, and they may need to have an open procedure or an osteotomy. We've been looking and performing in hip arthrosis in the very young patient using a tractionless technique for septic arthritis in children. The youngest one we did is about six months. We use a cannulated system. We use a two-portal system. Sometimes, we can use a single portal system. Very similar, got to use hip arthroscopy. We have a technique article that is available. I would encourage you guys to visit that. That's a little bit of a briefing on pediatric and adolescent hip arthroscopies. I really encourage you guys to contact me if you have any questions. I do think that we have a future. We're going to learn more. Our knowledge on pediatric and hip arthroscopy continues to expand FAI in patients. In the pediatric and adolescent patients, have excellent outcomes with limited complications. They seem to be very comparable to adults, but there are some caveats. You've got to pay attention to borderline dysplasia, and you've got to really think about the severity of the alpha angle because that may be correlated with the severity of the labral disease, no matter how bad their symptoms are. We do need to improve our knowledge on not only hip impingement, but the development of hip impingement in the growing athlete. Again, I think we're going to continue to expand the indications for hip arthroscopies within the pediatric and adolescent age groups. We have to continue to do it quite safely. It seems a little bit too premature to consider things like infantile DDH, although some international case studies have been presented and thought to be relatively safe. It's been an honor to participate in this series. Thank you very much for including me. Please don't hesitate to reach out if you have any questions regarding this slide or this presentation.

pediatric and adolescent hip arthroscopy

developmental changes

impingement

CAM lesions

prevention strategies