 University of Utah, Dr. Travis Mack. Dr. Mack is the Associate Professor with tenure at the University of Utah's Department of Orthopedic Surgery. He graduated from the Yale University School of Medicine, has done postgraduate education and training at the sports clinic in Hanover, Germany, hospital for special surgery in New York, New York, and the University of Ghent, Belgium. Dr. Mack is the medical director and head team physician for the Utah Jazz NBA basketball team and also is currently the associate editor for clinical orthopedics and related research in Philadelphia, Pennsylvania. Welcome, Dr. Mack. Thank you so much for inviting me to speak with you today. I'd like to specifically thank the Steadman-Philipon Research Institute and the USOPC for allowing you to present on the relationship between hip morphology, function and injury prevention. The elite athlete hip playing field is very different from that of the recreational athlete. FAI syndrome surgery occurs more typically in higher level athletes when they're younger. It occurs more often in males increased bilateral surgery frequencies. It is more often found in soccer, hockey and football, as well as cutting sports that occur at a younger age oftentimes result in surgery with higher level athletes. Higher level male athletes have a two to eight time risk of cam deformity, and this is specifically notable in hockey, basketball and soccer during early adolescence. FAI syndrome surgery fortunately results in approximately 74% or even higher return to sport. In my own and other experiences, this can be as high as 90-95% return to sport at the same level. Unfortunately, over 90% of individuals have an contralabeled injury that's noted at the time of surgical intervention. Males and FAI syndrome with sporting participation has been suggested to have an increased premature hip risk of osteoarthritis and this is something we would like to avoid. FAI syndrome surgery and sports participation requires us to also look at the individual sports and athletes in different positions. Hockey goalies have a notable severe internal rotation requirement and intraoperative simulated butterfly fly positions have been utilized to appropriately ensure adequate resections in these unique population individuals. And this is something we need to apply more commonly as it pertains to other sports. Female athletes have improved outcomes as compared to non-athletes following hip arthroscopy and this is obviously a positive perspective as it pertains to the group we're talking about today. We need to preserve and repair or placate the capsule in specific sports such as dancing, gymnastics and figure skaters and be very, very cognizant of either borderline or true dysplasia which allow these individuals to have super physiologic motion and be excellent at their sports but it also produces an increased risk of instability either a micro instability or post operative instability. Wrestlers may also fall into this group and we all need to pay close attention to that. Overhead athletes with FAI syndrome do very well fortunately after surgery. 97% have a return to sport which is excellent. Condrial injury unfortunately results in worse outcomes and some studies have suggested that because of this early intervention is important with individuals having symptoms less than three to six months should be having surgery with better outcomes as compared to those who wait longer. This video represents a patient of mine who had a large full think discontrol defect from the acetabular rim to the fovea representing 40% of his acetabular surface area. The goal of our research today is to try first to prevent this from occurring and second when it does occur to try to optimize the treatment so that we can improve the post operative prognosis of this young individual. The playing field of biomechanics form and function is important. Can we predict which athletes develop FAI syndrome based on the shape of their hip? Do athletes with abnormal hip anatomy compensate biomechanically? Should we operate in the asymptomatic athlete? Do certain athletes or sports create a hip at risk? Are there non-surgical measures that can mitigate this risk? And most importantly results of the data trying to answer the aforementioned questions. Can they be applied to screening a treatment program for these at-risk athletes? Shape modeling is also being used by our lab as well as others in attempt to objectify the diagnosis of FAI. We're trying to subgroup individuals with respect to sport and morphology and assess their severity as a percentile along a distribution curve. We're hoping this will allow us to template surgical resections and ideally optimize outcomes. Currently we're placing the femoral shape along what we call a hip T score and effectively mapping them as its variability in terms of severity in a volumetric fashion in three dimensions and comparing them to the relative current control shape which is a normal sphericity of the femoral head neck junction. Here's an example of mapping three different individuals along the control to the cam severity T score. We're hoping that this mapping technology allows us to start to quantitatively identify individuals and subdivide them into hips at risk. Of course it's not just a morphology it's also a function. With that we're then using motion capture analysis to qualify these individuals during athletic activity specifically the aforementioned sprint through the drop landing tests. We use EMG to record their muscle activity to quantify for neuromuscular and kinematic deficits. We're hoping to use this data to calculate true sport specific kinematics and we're doing this within different sports as not every sport is created equal nor is every individual within every sport. We're hoping this benefits our athletes by improving the understanding of the hip shape and biomechanical functions will ideally improve diagnostic accuracy and illuminate new treatment approaches. We're hoping that our results can inform the development of screening programs to identify at risk athletes and this data may support modification or elimination of sport specific training exercises that are currently employed to ideally promote muscle strength and kinematic control but may lead to symptomatic impingement and surgery. Ultimately our question is do athletes with abnormal hip anatomy compensate biomechanically and the answer is we believe yes but we're still studying this specific. The condor labral injury is specifically unique to the hip and that the concentricity of the femoral head and acetabulum is very different than any other joint in the body. Prior data suggests the condor restoration techniques may result in improved outcomes as compared to debreatment although ultimately the best scenario would be to not have the injury in the first place. We know microfracture amic and other condor restoration techniques have reasonable outcomes but unfortunately 98 percent of athletes that had hip arthroscopy had noted acetabular cartilage lesions and that was our data as well. Can we identify lesions pre-operatively using MRI if so can we stop these from progressing? We're hoping we can identify lesions that require treatment in a pre-operative status using a specific cartilage sequencing MRI. We're hoping we can optimize the treatment based on the size severity and location of the lesion and ultimately we're evaluating the role of the labrum and the condor labral junction regarding the progression of these injuries given the unique concentricity of the hip and the anatomy as a result of this. This MRI shows images of the hip that you saw previously. Notably he has subcondrocystic formation at the acetabular rim superiorly and anteriorly which has a negative impact on his post-operative outcome. It's something we'd like to avoid and if we can stratify this individual prior to this happening we can potentially impact the health of his hip for the long term and maintain his career as a professional snowboarder. Currently are trying to evaluate these types of condor injuries using two different types of cartilage specific sequences on MRI. One is called dual echo steady state or DES and the other is T1 row. We currently use a custom traction device to slightly distract the hip to allow us to specifically delineate between the femoral and acetabular cartilage. We do this on a three teslas semen's prisma and perform both sequences on each athlete. We get the athletes both from as football players, dancers, soccer players, basketball players and the cross players both male and female. We're evaluating them as freshmen and again as seniors to try to quantify the effects of sports specific injury or lack thereof on the asymptomatic athletes over a four-year collegiate period in each of those sports with the hope that we can identify at-risk individuals and improve our counseling of them during their sport. Moreover we are also trying to improve our ability to identify these condor and condor labral injuries using cartilage specific mapping. As a window to the future what we've identified currently is DES is much better and more consistent across different MRI machines and different institutions. Taking a single individual on two different machines with T1 row gives two different answers whereas on DES it's far more consistent and this is likely what we'll be using in the future but we will continue comparing both in our specific collegiate population. What about with the location of the condor labral injury? We evaluated this in a hundred of my own patients and what we found is it's very consistent. The image damage occurs between 12 and 3 o'clock in approximately 80 to 90 percent of our patients and the severity has the same location pattern. What this allows us to do is formulate a three-dimensional model and use finite element analysis to quantitatively calculate the effects of these condor labral injuries without actually having to injure patients or use or instrument on patients as in terms of our algorithms we can implement these algorithms in finite element analysis and evaluate what the potential effects will be. We performed this in a dysplastic hip using a large 15 millimeter defect in an area where we believe to be a hotspot it's more posterior than a typical FAI patient but the effects are still notable. What we found is decompression of certain areas while overload of other areas occurred and what we believe is the ultimately defects in certain areas in the subsequent transition of pressures in different areas may be why individuals get progression of osteoarthritis in the hip despite the concentricity. It's not a perfect hemisphere but rather there are undulations and pressure changes occur on an individualized basis. We then looked at an FAI model and looked at the role of contralaboral mechanics as far as the fluid and interstitial pressurization within the labrum and what we identified is one of the labrum's most important effects is controlling the interstitial fluid translation within the cartilage. Because of the concentricity of the femoral head in the acetabulum the fluid pressure within the cartilage is part of its ability to buffer the femoral head in the acetabulum during loading. When that fluid tries to squeeze out it is contained by the labrum itself and what that requires is an intact contralaboral junction. We found that the location of a defect significantly impacted the area of the pressurization within the cartilage resulting in higher loads in different areas. We also found that a labral tear resulted in significant increases in stress and strains and this isn't just with a full thickness defect but even with a contralaboral delamination that we see very frequently clinically that increased stress occurred when the labrum was involved even if the labrum and cartilage were delaminated together. What we concluded from that is preservation of the contralaboral junction was important. Transchondral strain catavaric evaluation has also been performed to ensure that this isn't just a biomechanical model but rather is applicable to human cadavers and that we can confirm our results. We took five human hip samples from four donors and cross sectioned them. We rotated to align the load vector plated them against a plexiglass window to control the femoral head in its normal anatomic position applied the load along a femoral neck axis. We used a speckle pattern to microscopically evaluate the transchondral tensile stresses and strains both within the cartilage the labrum and the bone. We statically loaded at one times body weight and then did a dynamic sinusoidal weight form and what you see is the very concentric hip controlling the normal patterns of tensile and shear stress loading with the exception of changes occurring at the chondralaboral junction on the top left of the cadaver. Specifically quantifying that what we identified were compressive and shear strains were highest near the osteocondral interface. Interestingly the tensile loads took a completely different trajectory. These were the highest near the articular surface of the cartilage and the normalized distance from the osteocondral interface was literally the opposite. Interestingly tensile stresses ultimately result in fissuring and cracking whereas delamination typically is due to compressive and shear stresses and those were at the level of the the chondralaboral junction. It is for this reason that we believe those chondralaboral delaminations occur. What we concluded from this data so far is that high strain chondralaboral junction exists and that chondralaboral preservation during labral pair is crucial. We used to completely remove the labrum from the acetabular rim and fortunately this has changed so now we're trying to preserve the chondralaboral junction and we believe based on our data that that is the most one of the most important things we can do surgically. In some cases it's not possible and we have to do things like label reconstruction but ideally if this can be avoided it ultimately probably will be better for the patients. As far as this impacting loading techniques what we found was dynamic loading may protect the cartilage and our suggestion so far is that cyclic loading may be more beneficial and safer and healthier in the post-operative phase than a static loading condition at least in the physical therapy realm. What about if prevention fails? Well we do have options microfracture, osteocondral autographed and allographed transplant as well as cell-based techniques have been utilized with good success. My perfect my preference for go-to as far as treatment for these is a single-stage arthroscopic amect which stands for autologous matric enhanced chondral transplantation. It allows single-stage arthroscopic implantation without pre-operative lesion detection which hopefully we're trying to avoid in the future and allow these to be detected detected early so our planning is more specific. Good results are preliminary and this is what it looks like in terms of the transplantation. This is cartilage that's removed from the femoral head at the level of the cam deformity prior to the osteocondroplasty and then retransplanted into the defect in the acid to the acetabulum and then added to grill factors and fixed with fibrin glue. As far as the data that supports this we've looked at the cartilage on the femoral head at the level of the cam in seven female and five male patients with mean ages of 33 and a BMI which is from the normal range. What we found is the viability of the time of isolation was approximately 52% but with a two-week culture it went up to 96% which is consistent with the growth factor mil-U which we applied in our lab. We're hoping that in the normal human environment we transplant these cells that they will have the same result with a 96% viability two weeks inside the body which will ultimately ideally anneal to the acetabular surface and allow us to truly restore these defects and ideally improve patient outcomes. Does any of this work was a question of mine and others and fortunately the answer is yes these are all preliminary studies without control groups or large numbers of patients but suggest studies would suggest that there are positive outcomes which can occur and it's definitely better than not treating them at all. Ideally we'd like to predict the future and stop it. We're hoping to use the biomechanics 3D acetabular and femoral morphology sport specific kinematics to allow us to modify sport specific activities, training regimens and reduce and eliminate symptoms and injury. A thorough understanding of conjural injuries and optimized treatment algorithms will be important and we're hoping to use clinical research including patient reported outcomes and cartilage specific imaging as a feedback on these algorithms. Last but not least remember the dreaded red dot the hip is attached to an athlete no matter how good we are at with our research and with the data-based algorithms that we have ultimate we have to listen to our athletes and if we are not helping them achieve what they want to achieve or feel like they need to then we need to reassess and question our ultimate results. Thank you so much for allowing me to be here today.