Good morning. My name is Dr. AJ Lal from the American Hip Institute in Chicago, Illinois, and today's topic is intraoperative fluoroscopy and dynamic assessment. My disclosures can be found on the AOS website. So surgical sculpture. Michelangelo once said, I saw an angel trapped in a block of stone, so I chiseled until I set the angel free. And I truly feel as though when performing femoroplasty, I've got a goal in mind. I want to perform a perfectly spherical shape. And no matter what the hip I'm working on presents with, that's the ultimate goal every single time. CAM management, as we all know, is not a basic technique. It requires surgical skill, practice, training. And really, we're going to talk today about some tips and techniques and pearls to achieve perfectly spherical contours of every case. Traditionally, surgical hip dislocation was the way access was gained to the femoral head neck junction. The goal was to achieve a convex sphere, and really, there was the use of spherical templates to achieve that goal. Now, when we are sculpting the femoral head, we want to utilize tools to help us get there. Viewing in the peripheral compartment, the femoral head neck junction is a three-dimensional structure. However, viewing through the arthroscope, we're seeing it in a two-dimensional view. This is analogous to looking at the earth from the horizon. We know the earth is round, but can we prove it? And can we see it from the horizon? No, we can't. We want to look at this femoral head neck region and know that we're going to take away just enough bone to make a spherical contour. We're going to do this utilizing fluoroscopy in multiple different views so that we have a perfectly spherical contour at all times. We want to maintain the labral seal against the femoral head when we are dynamically assessing the hip at the end of our femoroplasty, as seen here. So how do we do that? Well, again, when looking at the earth from the moon, we know the earth is round. So that's analogous to utilizing fluoroscopy in different planes of view to achieve that spherical contour. Let's take one step back and look at the background. We briefly mentioned labral seal. It does provide counterprotective fluid dynamics of the hip. Intra-resection, as we know, may result in residual FAI, but over-resection may disrupt the labral seal altogether. Three short videos, which I'm sure we all have a variation of on our own computer, one showing an intact labra with the maintenance of the labral seal. The second video is demonstrating injured labra with loss of labral seal, and third is going to be reconstitution of the labral seal with a repaired labra. This is with the anterior superior labrum removed. There's absolutely no suction seal. And lastly, with the repaired labrum. So what about under-resection? What does that do for the hip impingement? Well, it leads to residual CAM, and that can affect, as we all know, the chondrolabral junction. In this schematic, you can see how that residual CAM bump will come up, impinge against the chondrolabral junction, and continue to cause the patient pain and discomfort during hip flexion and internal rotation. Well, what about over-resection? What does that do to the labral seal? In this schematic, where you can see an apple or a shark bite, you can see that when the hip is flexed, there is egress of fluid from central to the peripheral compartment because there's loss of maintenance of that seal. That's in video number two that we just saw. There is no contact. And how does that affect the patient intraoperatively? Well, in this video here, during dynamic intraoperative assessment, even after a robust circumferential labral reconstruction, the patient had undergone an index procedure at an outside facility and had an over-resection of the femoral head. There is a loss of seal, as seen here with the egress of fluid during hip range of motion. You can't put that bone back. So does accurate spherical femoroplasty matter? Of course it does. When you have an errant femoroplasty and a 40-year-old police officer who needs to run and jump to do his job, there's really no recourse, and the patient will end up undergoing a total hip arthroplasty at a young age. In our hands, this is performed with a minimally invasive anterior approach, THR, with robotic guidance. The patient will do well, but will likely need a revision THR at some point in his lifetime. So looking at the search for a spherical femoroplasty, a study at American Hip Institute showed that CAM over-resection leads to inferior functional scores before and after revision hip arthroscopic surgery. Well, how was this done? So looking at over-resection versus under-resection patients, the purpose was to examine the effect of accuracy of previous femoroplasty on hips presenting for revision hip arthroscopic surgery. So all cases were performed indexed outside the Institute, and all revisions were performed inside the Institute. Patients were evaluated from June 2010 to August 2014. 120 hips were included in the study. The percentage of over-resection was calculated by finding a best-fit circle around the femoral head, calculating the distance from the edge of the deepest point of resection, and dividing that by a measurement taken as a percentage of the circle, diameter number B. Over-resected patients were identified as a greater than 5% margin of femoral head diameter over-resection. Under-resection patients were defined as having residual CAM lesion greater than 60 degrees, leaving us an optimal 5% margin of error. Results. Modified Harris hip and non-arthritic hip scores at presentation prior to the revision hip arthroscopy were lower for the over-resection cohort compared to the under-resection cohort. The modified Harris hip at two years or equal after revision hip arthroscopy were as well, lower for the over-resection compared to the under-resection cohort. The odds ratio of achieving PASS was 5.57 for the remainder of the cohort versus the over-resected group. Survivorship. There was a 30% conversion to THR in the over-resected group, again, likely due to the loss of the labral seal and rapid degeneration of the joint. There was 0% in the under-resection group. So the over-resected group had a 3.86 odds of conversion to THR compared to the remainder of the cohort. So in conclusion, at presentation, CAM over-resection predicted inferior clinical measures compared to the under-resection population. Over-resection predicted inferior outcomes even after revision hip arthroscopy and higher rates of conversion to THR. Therefore over-resection should be avoided at all times, if possible. So how do we perform a spherical contour? We've recently published a technique article on Pearl's Pitfalls in Optimal Surgical Technique. And really this is to highlight the position of the fluoroscope and the position of the extremity during the femoroplasty and having an algorithmic approach to achieving this in all patients being treated. We do utilize an intraportal capsulotomy. We perform traction sutures within the inferior leaflet of the capsule to provide adequate exposure as seen in the suture slack and suture tension pictures in the bottom right. Of note, we do not utilize a T-capsulotomy at all during femoroplasty procedures. And really looking at this in a clock face phenomenon, we want to know that each limb is being evaluated in its entirety. So we start at the hip in 45 degrees of hip flexion, zero degrees of rotation with the negative 30 degrees of cantilever of the fluoroscope, and then move progressively to provide adequate exposure to the medial femoral head neck junction, the lateral femoral head neck junction, and the more posterolateral aspects as we go throughout the stepwise process. And again, this is done algorithmically for all patients to achieve a spherical contour at all times. So in conclusion, you want to think perfect sphere, think convex. It's technically challenging, but with expertise can be done. And you got to use all your tools. Preoperative planning is important and using intraoperative multidimensional fluoroscopy is the key. The future, I think we're headed toward robotics, likely navigation, and virtual reality. These are to be determined, but fun things to think about. Thank you for your time.

femoroplasty

spherical contour

hip surgery

labral seal

femoroacetabular impingement (FAI)