I would like to thank Anna Programming Committee for allowing me to speak, so I'll be speaking on rim trim and camper imaging. Disclosures can be found on the Academy website. So we all know that the diagnosis and treatment of FAI really relies on the identification of FAI pathomorphology, which is obviously intensive in terms of the three-dimensional nature of it. And we also know that with surgical hip dislocation, we really get a circumferential visualization of the entire hip joint, and arthroscopy doesn't allow us to have the same level of visualization. So I think a couple things that we need to consider. One is, is our imaging sufficient to diagnose FAI, both CAM and pincer lesions? Secondly, is three-dimensional imaging required? And lastly, how can I optimize my surgical correction of FAI pathomorphology? So in my practice, I use plain x-rays as a screening tool in the office. And so every patient will get x-rays as kind of the workhorse. I like to get a standing AP pelvis, I'll normalize the pelvis, I'll do a Mohs circle around the femoral head and draw my lateral center of jangle, tonus angle, alpha angle as well, and I'll compare it to the opposite side. But we do know that plain x-rays may miss some of these deformities, especially when we're trying to identify CAM deformities, depending on where the exact location is. If we don't get the right lateral view, we may miss it, and so just keep that in mind. And so as far as two-dimensional imaging is concerned, I really use it as a screening test to rule in or rule out cases, and I know that obvious CAM and pincer deformities can easily be identified on x-rays, however, subtle deformities can be missed on plain x-rays. In addition, it's hard to identify global acetabular and femoral orientation issues on plain x-rays as well. CT scans can be really helpful, and I think it really is the gold standard in terms of identifying pathomorphology. This is a case where I was concerned about a crossover sign, but I think upon getting a CT scan, you can see that the subspine is very prominent. Also with CT scan, it allows you to get global and versional issues. Here you can see that when you measure it, they probably have a little bit of retrotorsion. There is some software available that can help you process these images and help you identify what is pathologic and what's not, and when you get a readout like this, it shows you that the center edge angle is about 36 degrees. There is a prominent subspine, which you can see, and there might be a little bit of acetabular undercoverage, but when you look at the femoral torsional issue, it's about zero degrees, so the McKibben index appears to be about 35 degrees, which to me seemed like it was reasonable. But the other thing is you can see on the femoral side that there really isn't much of a CAM deformity, and so in my mind, a case like this was mostly a subspinous issue. So arthroscopically, what you can see is you can see this labral tear from 12 to 4 o'clock very anterior chondrolabral delamination, a type 2b subspine that was decompressed. Labor was refixed, and based on the femoral imaging, it didn't appear to have much of a CAM deformity that required resection. So obviously, many of us may have concern about CT radiation, as I do myself, but I think our MRI imaging is getting better. We've done some studies in our lab just kind of comparing CT versus MRI, CT in green, MRIs in white, and you can see that they're almost identical, the CT and the MRI, and the white is basically no difference, and I think we're about within 0.2 millimeters of difference between MRI and CT scans, so stay tuned. I think that MRI imaging will be the gold standard coming up soon. Chris Larson has taught us how to systematically use our fluoroscopy to make sure that we've done a comprehensive resection of the CAM. He's taught us how to position the leg to really get that 1145 to the 230 position so that we can comprehensively address where the CAM deformity is most likely to exist. He also studied it and found that about 115 was the area in which the CAM deformity was most likely to be the largest, and I think our ability to process these images these days and to identify CAM deformities more precisely with better imaging techniques really can help us to fine-tune what we're doing and treat these lesions more precisely. And so there's some intraoperative computer navigation software that's available that will allow us to map out where the CAM deformity is based on these six locations that Chris has identified and also compare both pre- and post-resection what the imaging will look like, and here again this is not a large CAM deformity, but you can see with even a very subtle one if you've got the right image sequence, you should be able to correct it very precisely. As far as the pincer deformity, I think that fluoroscopic imaging can be helpful as well. However, the only thing I would say is that a lot of the pincer deformities are mostly on the anterior aspect of the acetabulum rather than the far lateral aspect. And so I think it's harder to detect, although if you do watch the acetabular wall, especially the anterior wall, you could notice a change. I think D. Matsuda has some nice templates in which he can help to visualize the anterior aspect of the acetabulum. But here if you've got a far lateral pincer deformity, you can see that these are ones that you can nicely see a correction on the fluoroscopic visualization, and in this case we also did a labor reconstruction. But here you can see a nice correction on the femoral acetabular side as well. So in summary, 2D imaging is a good screening tool but insufficient for preoperative planning. 3D imaging should be considered to have a comprehensive understanding of the FAI pathomorphology. Interoperative fluorography can be used in a systematic way to accurately identify cam deformities, and if we use the six standard views that Chris has taught us, I think we'd be able to leave the OR without any surprises. Thank you.

femoroacetabular impingement

diagnosis

treatment

imaging

preoperative planning