Ep 219: Are women less likely than men to return to sport after hip arthroscopy? With Dr Matthew King

[00:00:04] Hello and welcome to JOSPT Insights, the podcast that aims to help you translate quality research to quality practice. I'm Clare Ardern, the Editor-in-Chief of the Journal of Orthopaedic and Sports Physical Therapy. It's great to have you listening today. Hip arthroscopy is a pretty common surgical procedure in athletes and active people, and it's not surprising that this clinical population is focused on returning to sport.

[00:00:32] Today, my guest is Dr Matthew King, physiotherapist and senior lecturer from La Trobe University's Discipline of Physiotherapy in Melbourne, Australia. Matt's research interests include the hip joint, injury surveillance and epidemiology, and he put these skills to use leading a team that has synthesized and analyzed return to sport outcomes after hip arthroscopy from 45 studies and over 5,000 participants.

[00:00:58] The team's focus was on sex and gender differences and how the return to sport outcomes change with increasing time after surgery. The results are really interesting, especially if you're supporting athletes of all ages and participation levels to make informed decisions about treating their hip pain. Okay, let's hear more from Matt. Dr Matt King, welcome to JOSPT Insights. Thank you very much for having me. Pleasure to be here. It's a pleasure to chat with you, Matt.

[00:01:27] We're often talking about return to sport outcomes after knee injury, and today it's nice to move to a different joint. So, let's focus on the hip, and we're going to particularly talk about outcomes after hip arthroscopy, and also focus on some of the sex and gender differences in return to sport outcomes. So, to start, are women less likely than men to return to sport after a hip arthroscopy? The simple answer based on the review, the systematic review that we conducted is yes.

[00:01:57] Following hip arthroscopy, women had lower odds of returning to sport, especially as the follow-up time period or the times in surgery increased compared to men. Between one to three years after surgery, women are less likely to return to sport in the same sport at the same level or higher. And then beyond three years, women had reduced odds or were less likely to return to sport at any level.

[00:02:24] We'll get into some of the reasons or hypotheses for why that might be and what might explain those return to sport outcome or the differences in return to sport outcomes in a moment. I will also flag for people who are interested in the systematic review, there's a link in the show notes, and they can go ahead and read the full systematic review. We'll touch on some of the highlights today. It's always good, though, to get the full picture by reading the article, so I encourage our listeners to do that.

[00:02:52] I want to start a little bit with setting the scene for return to sport, Matt, because as you know, having worked in this field, there's a lot of different ways that people talk about return to sport. And you had a few different definitions. Tell us, what were those return to sport definitions you used and why did you need to use them? And this took a lot of back and forth in the early days when we gathered all the papers to be included in the review because of the differing definitions and how people describe return to sport.

[00:03:22] We used the IOC consensus statement to help inform our decisions, but we operationally defined return to sport based on two domains. First one, quite simple, is just level. So were people returning to sport at any level of participation and competition, or were they returning to sport in their chosen sport at the same level or higher?

[00:03:47] And then the second tier we defined return to sport was around what we termed currency. And this was primarily around the question of were participants in the study participating in that sport at the time of follow-up? So were they currently playing sport or had they ever returned to sport?

[00:04:12] So what I mean by that is current was really based around definitions in papers as to whether or not they were participating in sport at follow-up and the definition used in the paper at follow-up. And ever was looking at had they ever returned to sport by the follow-up time period.

[00:04:30] And this included individuals who made return to sport inside a five-year period, but by the time the five-year period rolled around for follow-up, they may not have necessarily been participating at that time. And we really had to do this to make sure we were making recommendations and outcomes for the review that were valid and to really deal with the variability and return to sport outcomes in the defined studies.

[00:04:58] Ultimately, we wanted to ensure that we were comparing apples to apples and not apples to oranges. And clinicians will find this very familiar. I'm sure clinicians will have worked with people who are playing sport right now and are still having some challenges or you've been as a clinician been working with someone for a while and then eventually they're back playing sport.

[00:05:21] You might check in with them versus someone who goes back to sport and then decides for whatever reason to either change their sport or decides that they don't want to play sport anymore. Life's changed and things have moved on. So I agree with you. It is really important to make that distinction. Let's come back to the sex and gender differences for a bit. How and why do you think return to sport outcomes are different for women and men?

[00:05:49] This was fundamentally the million-dollar question that we wanted to figure out. And so if you look at speaking to my definitions before the currently definitions, people particularly participating in sport at the time of follow-up. We did something in the review which was a meta-aggression, which is not as common as normal systematic reviews, meta-analyses.

[00:06:11] And we found that looking at any level across any period of time, women were 5% to 8% or the rate of women participating in sport was 5% to 8% lower than men. And if we look at the same level or higher, it was 7% to 10%. Now, potential reasons for these disparities is something that we really wanted to unpack in the review. And they can be wide-ranging.

[00:06:36] So they can be based on sex-specific biological factors such as bone morphology and hormone effects on exercise performance. It would be psychological considerations in and around differences in psychological readiness, return to sport or fear. And then also social factors, as you alluded to, life changes as time goes on. So whether or not it was influenced by individuals' employment or gendered roles or caregiving.

[00:07:08] And this is what we set out to really unpack in the review. However, the fact of the matter was that with the studies that were included, these sorts of social instructional determinants of health are very rarely reported and very rarely looked at. So we weren't actually able to hang our hat on these are the reasons why this may be different and instead present some different hypotheses as to why this may occur.

[00:07:33] So, for example, from, I suppose, sex-based factors and hip joint morphology, women may have greater laxity of their hip joint due to an increase in hip capsule volume and femoral head size. And that may contribute to differences in outcomes from a real, I suppose, patho-anatomical surgical perspective.

[00:07:56] And men athletes generally demonstrate a greater competitive motivators and a greater propensity for high risk-taking behaviors. So that may also influence it. Female and women athletes generally often have a heightened level of fear in and around re-injury, psychological distress with return to sport. So that could have influenced things as well. And then there's employment, there's education, there's life transition, there's caregiving responsibilities.

[00:08:25] And these all may influence these outcomes. I want to bring us back briefly to the return to sport outcome, how you've defined return to sport outcomes, because I think you're looking at quite organized sport as opposed to participating in physical activity. Have I got that right, Matt? Yes, yes. I want to bring us back to the return to sport. I think we've been to the return to sport.

[00:08:52] The reason I take us there is I wonder, and this is hypothesizing researcher hat on here, I wonder whether there are sex and gender differences or maybe gender differences in returning to sport versus returning to physical activity. And was that something that you either discussed as a research group or something that you are seeing coming through in the research?

[00:09:17] Is it that women have all of these other caring and social responsibilities, and so they're choosing not to go back to the organized sport, and they're still staying physically active? Or are women, are they choosing for lots of different reasons to stop being physically active altogether? At an anecdotal level and an opinion level, I would say that's probably true. These lifestyle factors and these transitions will certainly influence their ability and decision to return to sport.

[00:09:47] But we didn't specifically look at returning to general physical activity. So the opinionated part of me wants to say, yes, that's probably a large factor. The analytical part of my brain wants to say, I have no data, so we are unsure. But hopefully into the future, with this line of research that we're taking, we'll be able to unpack those things.

[00:10:12] Now, Matt, you mentioned you did a meta-regression, which is a bit different to what's typically seen in a systematic review with meta-analysis. Can you give us the short version of the difference between a meta-regression and a meta-analysis, and why a meta-regression is important here? Put quite simply, meta-analysis is really a comparison of, generally a comparison of two groups.

[00:10:39] In our instances, we were comparing men to women and their odds of returning to sport in these windows. The nice thing about a meta-regression is we can actually take time into account. So we took all our studies and all our data that related to currently participating in sport, and we built a regression model, like people say linear regressions. We built a regression model to look at whether or not return to sport currency, I suppose, decreased over time,

[00:11:09] which it did for both groups. And it also allowed us to look at and demonstrate that throughout that time period as well, women were offset to lower levels of return to sport. But I'm going to say, for me, with a maths brain, it's hard for me to explain it on a podcast without drawing a picture at the same time. But fundamentally, meta-analysis compares two groups, whereas a meta-aggression allows for us to look at change over time

[00:11:38] and the influence of sex, gender, and other factors at the same time. It gives you that capacity to add more variation and account for more variables, as you say, like time into the analysis. So it's a more sophisticated, higher-level meta-analysis is maybe a way for our listeners to think about it. I like that. Also, I'm a fan of a good-looking graph, and it also produces some good-looking graphs. It really does.

[00:12:07] It's another plug for the paper. And while we're back on the paper and the results of the meta-analysis and meta-regression, we better give the high level what were the return to sport rates so that we're setting the scene for people when they're going out into the clinic and sharing these numbers with patients. So looking at, I suppose, currency, whether someone's currently returning to sport,

[00:12:31] at six months post-surgery, around 82% of women will return to sport and 88% of men will return to sport. And that progressively drops off as time goes on. So we take things out to two years at 24 months. It's 78% of women and 85% of men. And then 48 months, so four years, you'll hit 70% of women and 80% of men. So it titrates down as time goes on.

[00:12:59] And then if we look at the same level or higher, these rates are lower. So two years for women, it's around 73% and 81% for men. And then four years post-surgery, it's 61% of women and 71% of men. Hip arthroscopy is used to treat a range of different hip problems, as you know.

[00:13:24] Were the return to sport outcomes very different depending on what the arthroscopy was used for? Something that we wanted to tease out, but the long and short of it is 90% of the papers in the review are all for femoral acetylal impingement syndrome, so FAI. There were only four papers in the review that looked at other diagnoses. And these were borderline dysplasia, the presence of intra-articular pathology.

[00:13:51] Another paper just had a variety of different diagnoses, which included FAI. And then another paper with not borderline dysplasia, but full dysplasia. So the results of the review are very much geared towards FAI and outcomes associated with FAI. And that's a good thing for our listeners to keep in mind. And so if you're working with people, with athletes, and athletes of all ages, I think

[00:14:17] this was not simply focused on elite athletes or professional athletes. This is athletes broadly with femoral acetabular impingement or FAI. These numbers are probably fairly ballpark. Whereas if you're working with someone who's had an arthroscopy to treat a labral tear, for example, you might need to take these numbers with a bit of a grain of salt. Correct. Yeah, 100%. That leads us nicely into my next question, which is how do you want to encourage clinicians

[00:14:45] listening to us today to use this information? So clinicians who are working with athletes who have had a hip arthroscopy, how would you like people to use and interpret and apply the information that's come out of your systematic review? Quite simply, I would say as an education tool. So returning sport is very important for athletes, and this is often how they judge treatment success,

[00:15:10] especially if their presentation or their hip pain and their hip condition has resulted in them not playing sport. So understanding return to sport outcomes and how they may change over time can facilitate really clear expectation settings pre-op, which can have benefits on improving post-operative outcome and post-operative interpretation of surgical success.

[00:15:36] I think it's really important for people to have real realistic and frank conversations pre-operatively with patients with regards to their return to sport outcomes. Because the fact of the matter is, is not every single person who has a scope for FAI will return to sport, and I think the default for some positions, some people in this position is to answer the question with will I return to sport? And the answer to default is yes, which unfortunately is not true.

[00:16:04] So using this data and this information to educate patients on what the outcomes actually look like can be quite helpful. So questions around will I be playing sport two years after surgery? The review basically demonstrates that for three out of four women, the answer is yes for any sport, but it's slightly higher for men. It's four out of five men, the answer is yes.

[00:16:28] And if participating in a higher level, in the same level or higher, the numbers are a little bit worse for women. So it's approximately two out of three. Two out of three women will be playing at the same level or higher at two years. But for men, it's just under four out of five. So setting these realistic expectations and educating patients on the outcomes of surgery so they can make an informed choice on how they rest. I like that.

[00:16:58] And I think it helps you as a clinician have a sense of what to expect and equally help the athlete or the patient in front of you get a sense of what to expect. I guess the other thing to point out here is like all research, we're talking about on a population group level as opposed to the individual in front of you. So just because the numbers say two out of three women are going to play sport doesn't mean that the person in front of you is going to play sport or is not going to play sport.

[00:17:26] So that's, I think, the challenge in clinical practice is trying to apply group level information to the individual. I agree. I have my little graphs printed out on a piece of paper that's laminated and that comes out when it comes out when I'm seeing people preoperatively or about to go into or contemplating surgery. So Matt, last question. Where does this research go from here? What's on your radar?

[00:17:53] What do you see as the next steps in trying to better support athletes to return to sport if that's what they choose to do after hip arthroscopy? Great question. And so many ideas and so many thoughts. So I'll keep it quite succinct. One of the things that really came out from this review from a research perspective is, I suppose, unlike knee and return to sport from ACL, a lot of this data is just pulled

[00:18:17] from retrospective chart reviews and retrospective analyses from large volume surgical departments and orthopedic departments. So the fundamental, there's two things that we're currently in the process of setting up. Well, it's one thing that'll cover two aspects. One is setting up a prospective return to sport study to look at individuals who are having

[00:18:41] surgery for FAI, getting their goals preoperatively, and then subsequently tracking them prospectively to evaluate their return to sport outcomes. And in doing that, also including exploring individuals' social and structural determinants of health. So we can start to unpack some of those factors in and around employment. How much does employment play a role or change in jobs or change in education?

[00:19:07] What effect does caregiving have, whether it be starting a family or caring for other family members with regards to their access to rehab and their return to sport outcomes? So that's the big pie in the sky that we're working on in the background here. Matt, that's really great to hear. Thank you to you and the team for putting the work into better understanding how we support athletes to return to sport, better understanding what it is that athletes want to do after they

[00:19:35] have a hip arthroscopy and particularly, as you say, after FAI, after surgery for FAI. It's been really wonderful hearing about where the world of return to sport outcomes after hip surgery or hip arthroscopy is at today. So Dr. Matt King, thanks for joining me on JOSPT Insights. Thanks for having me, Claire. Thanks for listening to this episode of JOSPT Insights.

[00:20:02] For more discussion of the issues in musculoskeletal rehabilitation that are relevant to your practice, subscribe to JOSPT Insights on Apple Podcasts, Spotify, TuneIn, Stitcher, Google or your favourite podcast app. If you like JOSPT Insights, help others find us. Tell your friends and colleagues and rate and review us. To keep up to date with all the latest JOSPT content, be sure to follow us on Twitter, we're at JOSPT, and Facebook, we're JOSPTOfficial.

[00:20:31] Talk with you next time.