This is Thomas Byrd, welcome to this ANA toolkit series where I'll reflect on indications for performing hyparthroscopy. My disclosures are available on the ANA website. I'm not going to share with you a laundry list of indications for hyparthroscopy, but really more just reasoning on why to consider this procedure. The most common indications are pain and dysfunction, dysfunction reflected by either diminished quality of life or degradation of performance that we'll see in athletes. But either way, the dysfunction is typically secondary to pain. I tell people pain's the body's alarm system. When the alarm's going off, we want to know what's setting it off. Is this an indication of future problems that requires proactive treatment or something that could be dismantled symptomatically? The richly innervated labrum is the most common culprit implicated in painful non-arthritic hip disorders. Keep in mind that the labrum is a hardy structure resistant to tearing unless there's some underlying predisposition. The two most common culprits are FAI and dysplasia. Most FAI can be addressed with arthroscopic intervention. As we know, significant dysplasia requires a reorienting acetabular osteotomy. But often we're faced with these hybrid patterns of FAI and dysplasia or borderline dysplasia. We've got to sort out which is the principal etiology that influences the treatment. Is it something that can be addressed arthroscopically or does it require a PAO? But when we think of dysplasia, everyone asks, what's the lateral CE angle? Well, the lateral CE angle is a single two-dimensional index that's poorly representative of the complex three-dimensional acetabular architecture. You at least have to know the anterior CE angle, the acetabular index, femoral version. They're all important, but just clues to interpreting the acetabular volume and orientation that can be revealed with current three-dimensional imaging. Neglect of dysplasia with an arthroscopic procedure when a PAO is more appropriately indicated is not just about iatrogenic instability or failure of your labral repair, but the reduced weight-bearing surface area results in increased contact force per unit area, and that can lead to accelerated articular wear. That's accelerated wear measured over years, and your intermediate results of arthroscopic intervention may not reflect these eventual failures. A few tips on differentiating the etiology between FAI and dysplasia. We look at the labral morphology and the pattern of damage. Remember that damage to the labrum with FAI begins anteriorly and then gradually migrates laterally, versus with dysplasia, oftentimes the damage begins laterally. We also tend to think of a shallow acetabulum having a hypertrophic labrum, but it's not necessarily a linear relationship between labral hypertrophy and reducing CE angle. We'll see shallow sockets with a diminutive labrum and well-covered sockets with a hypertrophic labrum. Another important observation with FAI, we see disproportionate damage to the articular surface of the acetabulum, and the femoral head remains well-preserved until late in the disease course, versus with dysplasia, we tend to see failure on both sides of the joint earlier in the process. We also look at the ligamentum teres, which is often hypertrophic, susceptible to degenerate rupture in association with dysplasia. Talk a little bit about the role of arthroscopy with advancing age. There are numerous studies that report poorer results with advancing age, and in fact, advancing age may be a contraindication to arthroscopy. Most of these are flawed because they do not account for the extent of associated articular damage. When we looked at our labral repair in patients over the age of 60, we compared that to a younger population, 18 to 55, that was matched for the severity of associated articular damage. We found that those with articular involvement on both the acetabulum and femoral side were more likely to go on to hip replacement, and that was true regardless of age. Associated articular damage is bad regardless of your age. But there are other factors at play when we look at an older population. How important is labral restoration in an older patient, but also the obligate rehab process that goes along with your labral repair? We'll shift slightly to the role of arthroscopy in arthritis. Everybody asks how much arthritis is too much for hip arthroscopy, but that's not the right question. The proper question is when does the pendulum swing from being a preventative procedure to being a palliative procedure? When is the damage far enough along that you're not really preventing what's going to happen later? You're just hoping to reduce their discomfort. And that's where a hip replacement for a palliative procedure is the most successful of all operations in orthopedics. So that's a very high bar against which to measure your arthroscopic approach. A couple of non-starters are tonus three changes less than two millimeters of joint space. But what about tonus two changes? And our experience has been that maybe, maybe not. The results are not as good as those with normal radiographs, but it may be appropriately indicated in the right person who's motivated, they have the right attitude and expectations of the procedure, and they're not keen on a hip replacement, sometimes it may be a consideration. A few miscellaneous comments about some miscellaneous disorders. Arthroscopy for a septic hip may be appropriate. Sometimes it depends on more mundane factors like where the patient is, what sort of staff and equipment you have available. If it's nighttime on a weekend in the hospital, it may be better just to do an arthrotomy. But arthroscopy is an appropriate consideration. And interestingly, this is the only article that really addresses the subject, work by Robbie Westerman, where he showed that an arthroscopic approach was as effective as an arthrotomy. Loose bodies, certainly that's how I got started in hip arthroscopy. In foreign bodies, who wouldn't want to take the bullet out of a hip and hear the clang as it goes into the metal kidney base? Like calviperthes disease, there are some really ingenious, innovative osteoplasty techniques to restore the anatomy of the hip. But for those who are not a candidate for an open procedure, and if they've got good joint space preservation, arthroscopy may be a consideration. The four sources of pain that we identify are loose OCD lesions, sometimes just loose unstable articular fragments from the femoral head, labral tears, and rupture of the ligament arteries can cause pain as well. Typically, these are people in their 20s and may be an alternative to just tell them to live with it until they're ready for a hip replacement. In our experience, looking at this with two to 10 year follow up, the results can be favorable. Synovial chondromatosis, it seems like it's usually compounded on top of FAI, but FAI is such a ubiquitous problem that probably just go hand in hand. Don't ever tell them you can get all the loose bodies out. I think you're overstretching to say that. If they do have to undergo revision surgery, the results can still be favorable. Don't fool yourself thinking it's recurrent disease. You're not eradicating the disease and it comes back. It's just residual disease because you really can't get all of it out. In our experience, a quarter of these were unsuspected prior to arthroscopy. Our reoperation rate was 18% but could still be successful. Pigmented villanodular synovitis comes in nodular and diffuse forms. Again, you cannot say that you can do an absolute total synovectomy, but the arthroscopic approach is favorable because many of these have associated articular involvement that may mean they're heading towards an arthroplasty in the future. In that setting, you hate to have exposed them to a big open procedure. In our results with 2-10 year follow-up, more than half of these were unsuspected prior to arthroscopy. Again, the diagnosis is not always as evident as you would think. In closing, I'd like to quote Henry Marsh who's a noted neurosurgeon, humanitarian, and author from England who said that it takes 3 months to learn how to do an operation. It takes 3 years to learn when to do an operation. It takes 30 years to learn when not to do an operation. I think there's a lot of wisdom in that. At this point, I'm going to stop and turn it over to Dr. Christopher Reddy who will be speaking to you about when not to operate on these hips. Greetings from Nashville.

hip arthroscopy

femoroacetabular impingement

periacetabular osteotomy

acetabular dysplasia

synovial chondromatosis