Hip dysplasia, arthroscopy is enough. My name is Dr. Shane Ngo. I'm at Rush University Medical Center. My disclosures can be found on the Academy website. So this is a case example of a borderline dysplastic hip that we've all seen. An 18-year-old hockey goalie, butterfly position, comes in with bilateral hip pain. Here are his x-rays. You can see he's got clear evidence of dysplasia. He also has other features that are concerning. He's got retroversion. He's got a posterior wall sign, ischial spine sign, as well as a crossover sign. When you look at his lateral center edge angle, he's 22 degrees bilaterally, tonus angle of 18 degrees bilaterally as well. When you look at his femoral side, you can see he's got clear cam deformities, alpha angle of 62 degrees on the right and 69 degrees on the left. So this is a case that I think would be an excellent canner for arthroscopic intervention. Obviously, the patient has large cam deformities that require complete surgical correction of the cam deformities. And I think the soft tissues, as I think we're talking about, is really important and critical to preserve. That includes the chondrolabral junction. So in the lower inset, you can see how a lot of these labral tears are very extensive and go much more anterior than normal. And the capsule is really important. As we're talking about laxity and soft tissues, in these cases, I'll try to make as small a capsulotomy as I can. If you saw when we started, we had what I call like a mini T-capsulotomy. And it's really about the size of like an eight millimeter cannula. And I'll go ahead and place these vertically oriented stitches with high strength sutures. I'll use a capsular repair device. I'll basically put three stitches on the vertical side. And now we're gonna close the horizontal side. And so I'll place either two or three stitches on the horizontal side to close the side to side to close the repair for a complete capsular closure. And so with these types of repairs and placation maneuvers, you can get a really watertight seal. So you're able to restore the biomechanical characteristics of the iliofemoral ligament. Here, we're putting in our last stitch on the medial side, and you can get a really nice watertight seal. And so I think that's our goal with these patients is that we wanna preserve the soft tissues, but we also wanna correct the bony deformity as well. Okay, so that's the final look here. Can we advance the slide? Okay, so the anatomy, as Jeff had talked about, is important to understand, and really is a complex interplay between the bony side as far as on the establisher side and the femoral side. But I think as far as the conversation stands, we just wanna be clear. When we're talking about borderline hip, probably the easiest way, the most reproducible way is to look at lateral center jangle. Normal's about 25 to 40 degrees. The borderline group is, in this conversation, will be 18 to 25 degrees. And a true dysplastic hip, we would say about 18 degrees. And I know this is oversimplified. Andre's probably gonna talk about ways in which we should also look at different parameters. But when you look at the dysplastic hip, we know that there's more load going through the chondrolabral junction. And not only is the labrum getting more pressures, but the cartilage as well in a dysplastic hip. We actually did a CT scan study looking at dysplastic, moderate and severe dysplastic hips and determining whether or not this changes the bone mineral density. And what we've done is we took the CT scan and we did bone mineral density analysis and then basically measured between that control, borderline group, moderate and severe group, and found that there was no difference between the control and the borderline group in terms of the bone mineral density. So one way just to look at the contact pressures that are going in the acetabulum. When we look at the literature, the evidence for borderline hip dysplastic, as far as the arthroscopic treatment has been published by Dome Series as well as Chris Larson Series. We've got level three evidence with the HSS Series and the MASH Group Series. And we have five-year data as well that's published benefits of the arthroscopic intervention. So this is looking at their lateral center of jangle. Again, roughly between 20 and 23 degrees with a low revision rate and a increased improvement in terms of their modified Harris Hip Score. And I think most importantly, no conversion to PAO or total hip replacement in any of these series that have been published. When we look at the MASH Group, when we compared normal versus overcoverage and undercoverage we found that there is no significant difference in terms of their patient report outcomes. And there was a low conversion rate to total hip replacement, about 2%, and a revision rate about 4.4% in the MASH Series. In our own clinical series, when we look at our two-year data, we did find that the borderline group and the control group had a similar achievement of MCID, about 87%, 86%. Failure rate was very low, 0.8% revision rate and 0.8% conversion to total hip replacement rate. And the independent predictors of achieving MCID included lower VMI, lower alpha angle, and female gender. We have a five-year data that's also showed similar in terms of achievement of MCID between the borderline and control group. And we also found that the predictors of achieving MCID was females and physically active patients. When we look at the survivorship of the PAO population, this is a series coming out of Boston showing that there is a failure rate of about 9% in terms of a low modified hair-tip score and about an 8% complication rate. So I think you gotta bear in mind complications as well as their patient report outcomes. So when you compare arthroscopic intervention versus PAO intervention, I think that there's definitely some nuances in terms of the conversation. But I think it's really important to kind of get in the weeds. Arthroscopic intervention using contemporary techniques as far as label refixation and capsular management as well as complete surgical correction of impingement is a good treatment for the borderline hip. Most of these borderline hips have large cam deformities. I think those are kind of the ideal populations. We talked about these males with borderline dysplasia as well as large cam deformities. And the clinical evidence does show excellent outcomes with a low failure rate in a properly selected patient population. Thank you.

Dr. Shane Ngo

Rush University Medical Center

borderline dysplastic hip

arthroscopic intervention

cam deformities