Welcome to this ANA toolkit series. My name is Thomas Bird and my charge is to reflect on the natural history of FAI. My disclosures are available on the ANA website. With regards to the natural history, the first relevant topic revolves around duration of symptoms. There are numerous studies that report poorer results the longer the duration of symptoms. But does that mean that you really need to operate right away? From my perspective, the answer is not necessarily for reasons that we'll reflect on. But for athletes that land on my doorstep looking at surgery, one of their biggest sources of frustration is, well, they tried injections and therapy and now I need surgery. Well, the reason we're looking at surgery is because they failed injections and therapy. And as you're dealing with athletes, it's just important to emphasize that just because you're not recommending surgery does not mean that this isn't a significant problem. And having them in the loop on the decision-making process is important. FAI is a chronic process and regardless of the suddenness of the onset of symptoms, it's the culmination of the cumulative effect of a disorder that's been present since childhood. The problem has been developing long before first becoming symptomatic. And that's important to remember as part of your decision-making. They've been compensating long before the joint first becomes symptomatic. And the compensatory problems may obscure the underlying joint disorder. And that's where the rehab process can assess and address compensatory problems, reduce symptoms, improve function and performance, and sometimes regain the ability to compensate. This paper spearheaded by Chris Larson that we authored together, we looked at two years of the NFL Combine, all the players coming through, 90% showed some radiographic feature of FAI, but we found that the increasing alpha angle was the most relevant as far as whether they were symptomatic. And we've learned that the severity of the CAM lesion correlates the most with the magnitude of articular damage, and that can be characterized by greater alpha angle, reduced head and neck offset, and decreased range of motion. To me, FAI is like the front end of your car being out of alignment. It leads to some uneven tread wear, and how quickly and severely that wear occurs depends on your driving habits. And we find that kids don't get into trouble with FAI unless they're involved in sports. They're driving their hips like Porsches, not like Priuses. And that's important because the treatment isn't simply, when can I get back to sport? The treatment is about a young person with a lot of years ahead of them trying to make sure we're giving them the best tip we can for a long time to come. When we looked at our adolescent athletes, we found that virtually all, 96%, were involved in athletic activities compared to our adult population, which was less than two-thirds. When we mined more deeply at FAI and adolescent athletes, 97% showed improvement, but only 86% returned to their sport. Now when we looked at those, those that didn't return were about one-third weren't able to. About one-third thought, well, maybe it's not such a good idea to go back to that sport. And about a third had simply finished their high school career and weren't playing the sport in college. So the numbers perhaps aren't that bleak, but when we're counseling families and talking to parents, I think it's important we tend to give them the lower number just to emphasize the reality of the long-term nature of the concerns that we have for their children. When we published our experience on FAI for CAM impingement 15 years ago, we found a bimodal age distribution. One peak was at 43 years. This is a typical early age onset osteoarthritis. The other peak was at age 20, and these were the young adults pushing their hip beyond the reduced physiologic limits, mostly with athletic activities. But the concept of FAI is too simple. It easily explains how some people get into trouble, but how are some active individuals life-long compensators with FAI morphology that never develop FAI pathology? We know that femoral version is important. We know that increased femoral version can lessen the effect of a CAM lesion. Increased version does raise our concern about potential iatrogenic instability with our surgical procedures. We know that reduced femoral version can heighten the effect of a modest CAM lesion. It can also create pincer-type damage to the labrum, even with normal acetabular architecture. Reduced femoral version allows it to collide against the rim, damaging the labrum. Sometimes you have to make a decision. Am I going to address this by conservative rim trimming, or do they need a formal femoral rotational osteotomy? This is not entirely a static process. It's very much a dynamic component to FAI with pelvic orientation that can influence the impingement. We know that lumbar lordosis can heighten the effect of FAI, and kyphosis can lessen the dynamic effect of FAI. And that's where physical therapy can genuinely have a positive influence on this, reducing the forces across the joint. Subspine impingement sometimes is a little bit in the eye of the beholder. Clinically, people talk about being able to differentiate rim impingement, where they have pain with flexion, adduction, and internal rotation, versus subspine impingement, where they have pain with straight hip flexion. I'm not sophisticated enough to make that differentiation, but one of the observations we've made is with subspine impingement, sometimes you'll get a false negative response to your diagnostic test of anesthetic in the joint. The subspine impingement is extra-capsular, and they might not necessarily get the pain relief from the intra-articular injection. So when you have somebody who seems to have FAI, but they don't have the response to the injection, at least think that there could be a subspine component in play. Variable demands of different activities, I think FAI can negatively influence these in different ways. And I think in the future, we probably will have boutique methods of FAI correction customized to individual's needs and demands. But I also wonder if FAI may be advantageous for some sports or positions. For example, with offensive linemen, if their hips are a little stiff, I wonder if that may give them a more stable base for blocking. I'm not sure how that ties in with the observation that we've made in football players, that offensive linemen are the one position that tend to do most poorly with surgical correction of FAI. I do know that all bull riders have incredibly stiff hips, and I think it may be advantageous that they can kind of clothespin themselves on the back of the bull. As far as symptomatic FAI, once somebody becomes symptomatic, it's unlikely that the problem is just going to get better and go away. Sometimes if it's evident that they're in trouble with the joint and surgery may be the most definitive course. But that doesn't mean that their only choices are suck it up or recommend surgery. There are various strategies to help modulate the symptoms. If symptoms are stable, I think a non-operative strategy is appropriate. If the symptoms are worsening despite conservative measures, I think it's wiser to recommend surgery rather than just wait and see how much worse it gets. Again, we emphasize that just because you're not recommending surgery does not mean that this isn't a serious problem. I'm not opposed to judicious use of intra-articular corticosteroid injections, but it's the purpose and how you use these. We'll use the injection in the joint to get the joint quieted down to see if supervised physical therapy can be more effective, a better chance to correct the compensatory disorders, may regain their ability to compensate, but at the very least, it puts them in a better position for successful surgical recovery with this operation. Lastly, sometimes it's just a last line of non-surgical treatment to say that you checked all the boxes and tried everything else before leaping to surgery. I don't think a one-time injection is going to compromise the long-term outlook for anybody, but certainly a multitude of injections are ill-advised. You're treating the symptoms and not addressing the problem, and that can have substantial negative consequences. A couple of comments about orthobiologics. Typically, we think of PRP and stem cells. We know these are really minimally manipulated stem cells, but think about the role of these products are really two purposes, either to potentiate healing or to modulate the symptoms of osteoarthritis. FAI is a structural problem, and that's why all the orthobiologic injections in the world aren't going to correct a structural problem. In closing, most hip disorders are multifactorial, very much a perfect storm. You have enough factors coming together just wrong to get the individual into trouble, and as a clinician, you may never identify all of the factors, but if you can identify enough factors that you can address with both non-surgical and potentially surgical treatment, that may be the best that you can hope for on a good day. With that, greetings from Nashville.

Femoroacetabular Impingement

Thomas Bird

rehabilitation

treatment strategies

athlete involvement