I'm sorry I'm unable to join you in person. Tonight I'm going to discuss when you cannot fix it with a scope, when to consider open hip preservation surgery in the setting of a failed hip arthroscopy. Here are my disclosures. So today I'll discuss when open hip preservation surgery is clearly the right answer in the failed hip arthroscopy, and then we'll spend most of our time talking about those situations when it's not obvious that open surgery is the right answer. Open surgery is the clear choice in frank hip dysplasia. The normal lateral center of jangle is greater than 25 degrees. If the LCEA is below 18 degrees, it's clear that the patient has dysplasia, and so a hip arthroscopy alone is not the appropriate treatment. The PAO is performed with a series of osteotomies around the hip that allow us to move the acetabular fragment. The goal of the PAO is to cut the acetabular fragment completely free from the rest of the pelvis, and then rotate the acetabular fragment to provide more coverage to the femoral head. Another clear indication for open hip surgery is Perthes. Perthes disease is more commonly seen by pediatric orthopedic surgeons, but as sports surgeons we will likely see the adult sequelae of Perthes disease. Adult sequelae of Perthes will be coxa magna, coxa plana, trochanteric overgrowth, coxa breva, limb length discrepancy, acetabular dysplasia, or osteochondritis desiccans. This was a 30-year-old patient who presented to my office for insidious onset of right hip pain over a few months. He had never before had hip pain, and had never been diagnosed with Perthes, but admitted to having noticed he walked funny throughout his lifetime. So in this patient, we performed an open surgical hip dislocation, open femoroplasty, relative femoral neck lengthening, and concomitant PAO. And of course, when a joint is too arthritic for hip preservation, we know that a total hip replacement is a better option. So now let's focus on those situations when open surgery is not always the clear choice, but may be the right choice. I'll specifically focus on borderline hip dysplasia, femoral version abnormalities, and considerations for when you might offer a surgical hip dislocation instead of a hip arthroscopy. The first and probably most popular topic is borderline hip dysplasia. Borderline hip dysplasia is defined as a radiographic lateral center at jangle either between 18 and 25 degrees, or 20 and 25 degrees, depending on the literature source. There's a very high prevalence of labral pathology in symptomatic borderline dysplasia, upwards of 90% of all borderline hips. So it's important to keep borderline dysplasia in the differential when patients present with a labral tear or re-tear after prior hip arthroscopy. There have been a number of studies which have demonstrated that hip arthroscopy can work in borderline dysplasia patients. But when considering hip arthroscopy in borderline dysplasia, it's important to recognize that not all hip arthroscopy is the same, and that this patient has already failed a hip arthroscopy. There's a significant difference in outcomes of hip arthroscopy in the borderline hip, depending on whether the labrum and capsule are repaired or not. Without capsule or repair, there's been up to a 60% failure rate of hip arthroscopy reported, with almost 40% going on to have accelerated osteoarthritis. These changes, if they've occurred, will certainly make any revision hip arthroscopy less predictable. But even when the hip arthroscopy is performed well, there are numerous non-modifiable factors outside of our control which can lead to failure of the hip arthroscopy in the borderline hip. If you look at this list, it's quite extensive. And if we look more closely at those reports that hip arthroscopy can work in borderline dysplasia, we should probably emphasize that these are high-volume expert hip arthroscopists who achieve these results. These surgeons are regularly repairing or reconstructing the labrum and capsule. While historically the indications for PAO have simply been hip dysplasia, now the PAO is used for various degrees of hip dysplasia, including borderline dysplasia, significant acetabular anteversion or retroversion, focal acetabular undercoverage, or hip instability either with or without radiographic evidence of dysplasia. The outcomes after PAO are a 10-year survival rate of the native hip of up to 95%, and the 15-year survival rate has been reported as high as 92%. The complication rate is very low at about 1%. A majority of patients who get a PAO will go on to return to preoperative or higher levels of activity. And the PAO has shown excellent outcomes even in the minimally dysplastic patient. Now we know that in frank hip dysplasia, the undercoverage of the femoral head leads to decreased area of load transferring and elevated joint contact pressure. And this leads to early hip arthritis. The question remains as to whether this is the same natural history in borderline dysplasia. Though more recent literature has suggested that the characteristics of the borderline dysplastic hip, based on intraarticular injury pattern as well as three-dimensional CT analysis of acetabular morphology, are in fact more similar to dysplastic hips than to hips with normal acetabular coverage. So we should keep the dysplasia natural history of early onset of osteoarthritis in mind. One amazing thing about the PAO is that not only does this procedure treat pain related to hip dysplasia, but it reverses the natural history of hip dysplasia and gives the dysplastic hip the same natural history as a normal hip. One question to ask in the field hip arthroscopy is whether borderline dysplasia was missed. There are a number of radiographic parameters which have been described for the dysplastic hip. But in my practice, I use the lateral center edge angle and the tonus angle the most. When you're measuring the lateral center edge angle, it's important to note where the sore seal ends laterally. In this patient, the upturn of the sore seal is not providing thermal head coverage. So there will be a significant difference in the LCEA measurement if you measure to this point versus this point. Here you can see the difference in center edge angle measurement based on where that angle is drawn laterally. I would say that the image on the far right represents the true center edge angle and you can see that there's a nine degree difference in the measurement of LCEA on this patient's radiographs. But it's also becoming apparent that the lateral center edge angle is not enough. In one study, up to 39% of normal hips as defined by the center edge angle are actually mildly dysplastic by the tonus angle measurement. The acetabular inclination or tonus angle greater than 10 degrees is an indication of hip dysplasia or instability. Other described radiographic measurements include the femoroepithecial acetabular roof index or FEAR index. The cliff sign has also been described as a radiographic finding associated with hip instability. The false profile view can give a sense of anterior acetabular coverage as well as subspine morphology. In some patients, it may not be clear how undercover their hip is until you obtain CT imaging. With this three-dimensional reconstruction, you can see much more of the femoral head than I would have expected based on the x-ray alone. The Ottawa classification describes acetabular undercoverage as either anterior, posterior, anterolateral, posterolateral, or global, which expands on that more traditional LCEA measurement. And here's an example of a normal acetabular coverage based on lateral center edge angle measurement in a patient who had had a prior left hip arthroscopy with rim trim. However, if you look carefully at the outline of the anterior wall and the posterior wall, you can see this patient has focal posterior undercoverage. Sometimes inverting the radiographs will help you better visualize the outlines of the anterior and posterior walls. On the left, I've measured the lateral center edge angle the way it's described, to the lateral most edge of the source heel on an AP radiograph. However, on the right, I've measured the angle to the lateral most aspect of where the posterior wall meets the source heel. You can see that the posterior acetabular coverage is consistent with dysplasia. Also keep in mind that the diagnosis of hip dysplasia is technically a radiographic diagnosis, while hip instability is a clinical diagnosis, but they often go hand in hand. Clinical exam findings, such as the Baton score, can assess for ligamentous laxity. There are also several provocative maneuvers to test for hip instability. I use the anterior apprehension test and the prone apprehension relocation test the most. In my practice, if the patient has recurrent intraarticular pathology and dysplasia, we can address both with a combined PAO and hip scope. I typically perform these in the same surgical setting. In fact, the entire hip arthroscopy and PAO can be performed on one table with one prep and drape. As we're indicating borderline hip dysplasia patients for revision surgery, we should keep in mind the consequences of choosing the wrong surgery, which I would argue are worse if you mistakenly choose hip arthroscopy. There are significant consequences of choosing hip arthroscopy in the borderline hip that should have had a PAO. The prevalence of failed hip arthroscopy undergoing subsequent PAO has increased 192% from 2008 to 2015. Additionally, about 33% of patients required additional work to address labral pathology, suggesting that the underlying pathomechanics continued to cause damage to the labrum even after initial labral repair. A failed hip scope prior to PAO may result in significantly lower patient-reported outcome scores after PAO. And while there are a number of studies showing no impact of prior failed hip arthroscopy on total joints, there are a couple of studies that do indicate an increased risk of revision periprosthetic infection and aseptic loosening, so there's a potential that these failed hip scopes have consequences further down the line. There's also the possibility that the hip scope is attempted first and subsequently there is rapid catastrophic progression to end-stage osteoarthritis. This has been reported multiple times in the literature and typically happens within a year of the hip arthroscopy. You will most often see this in patients who are either dysplastic or borderline dysplastic. Now a second situation where open surgery may not be the obvious choice is with femoral version abnormalities. Normal femoral version is around 15 degrees of antiversion and femoral version is the anterior tilt of the femoral neck and is measured by finding the angle between the line tangent to the distal femoral condyles and the line up the femoral neck. Surgical techniques used to correct abnormal femoral version include an intramedullary saw and nail, intratrochanteric osteotomy and blade plate, a subtrochanteric osteotomy with plate, or a distal supracondylar osteotomy with plate. In each of these methods, the goal is to correct increased retroversion by rotating the distal fragment internally and to correct increased antiversion by rotating the distal fragment externally. The goal is to achieve 15 to 20 degrees of antiversion. In my practice, femoral derotational osteotomy is relatively rarely indicated. I'll use it when all other possible sources of hip pain have been addressed, including with arthroscopic or open surgeries, and patients continue to have hip pain that we think is due to excessive antiversion or retroversion. The patients who end up getting this procedure will often have the lower extremity phenotype of excessive version. They either walk with an in-toeing or out-toeing gait. If patient's foot progression angle, whether in-toeing or out-toeing, may be an adaptation to avoid pain due to either instability or impingement symptoms. In the foot progression angle walking test, patients may exacerbate pain related to version abnormalities. A third situation when an open procedure might be better than a revision hip arthroscopy is when considering whether or not to use a surgical hip dislocation. The surgical hip dislocation was initially the gold standard treatment for FAIS. Now, given the advances in hip arthroscopy, we don't do surgical hip dislocations nearly as often. But indications can include severe hip deformity, whether that's significant version abnormalities, a high-riding trochanter, coxa profunda or coxa protrusio, or for certain femoral head chondral lesions. So here's an example of a patient who presented with right hip pain, coxa profunda, a diminished femoral head neck offset, and a labral tear. I indicated her for surgical hip dislocation, which allowed me to perform an open CAM decompression an open labral reconstruction with allograft, and an open acetabular rim trim. A large osteochondral defect is another indication for open surgical hip dislocation. In this 27-year-old patient with a 2-centimeter osteochondral defect, I performed a surgical hip dislocation with Oates procedure. Here you can see one-year post-op radiographs demonstrating a resolution in the osteochondral defect. And then keep in mind that arthritis could be lurking in some hips, which may make hip preservation not worth it, even in patients like this 27-year-old with a history of Perthes. If you look closely at the femoral head, you can see a large osteochondral defect in the central femoral head. So in this case, it may make the most sense for her to go straight on to total hip replacement. So in summary, the open surgical alternatives to hip arthroscopy that you should be keeping in mind are the surgical hip dislocation, femoral derotational osteotomy, and periacetabular osteotomy. And of course, the total hip replacement when hip preservation doesn't make sense. Because borderline dysplasia is what you'll probably be seeing most often, make sure you're familiar with the Taunus angle and how to correctly measure the lateral center edge angle, as well as how to evaluate for clinical instability in the hip outside of radiographic dysplasia. Thank you.

open hip preservation surgery

hip arthroscopy

periacetabular osteotomy

borderline hip dysplasia

surgical hip dislocation