Does the time to surgery influence outcomes for patients with a hip fracture who undergo total hip arthroplasty?

Listen to Andrew Duckworth, Luke Farrow and Nick Clement discuss the paper 'Does the time to surgery influence outcomes for patients with a hip fracture who undergo total hip arthroplasty?' published in the November 2023 issue of The Bone & Joint Journal.

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Transcript

[00:00:00] Welcome everyone to our BJJ podcast for the month of November. I'm Andrew Duckworth and a warm welcome back to you all from your team here at The Bone & Joint Journal. As always, we'd like to thank you all for your continued comments and support, as well as a big gratitude to our many authors and colleagues who take part in the series that highlights some just some of the great work published by our authors each month.

So today I have the pleasure of firstly welcoming Mr Luke Farrow who is a clinical research fellow at the University of Aberdeen and the current chair of the Scottish Hip Fracture Audit Research Committee to discuss their paper entitled Does the time to surgery influence outcomes for patients with a hip fracture who undergo total hip arthroplasty?: a nationwide study from the Scottish Hip Fracture Audit' which has been published in the November edition of the BJJ. Welcome Luke, it's great to have you with us today. Yeah thanks very much for having me. And joining Luke is his co author on the paper and my great colleague and friend here in Edinburgh Mr Nick Clement.

Nick, great to have you back with us. Thanks for the invite back. I do appreciate it. I didn't think you'd invite me back after last time. Very kind of you. Pleasure. Pleasure. So Luke, the aim of this study was in relation to patients undergoing total hip replacement for hip fracture and how they commonly experience a surgical [00:01:00] delay in order to access the surgical expertise required

to perform the surgery. And in sort of relation to this, there are known associations between delay to surgery and inferior outcomes for hip fracture patients, which we know. Whether this holds true for this patient population is, is sort of unknown. So therefore the aim of this was to sort of look at whether that surgery has an impact on key health outcomes for this patient population.

So Luke, maybe just as a background to study for our listeners, just a brief overview of the literature in this area or what we already know, or if we know anything and what caused you to actually look at it in particular. Thanks, Andrew. So, I mean, I think there's been good evidence in the past that the kind of the risks of undergoing a total hip replacement for hip fracture are generally different from those undergoing elective kind of hip replacement.

However, at the same time, we also know that the population who undergo a total hip replacement in this setting are generally fitter than their peers and do not have the same kind of risk profile as general kind of hip fracture patients. So it's really about trying to understand kind of where this group sits and [00:02:00] help clinical teams on the ground kind of making decisions about whether it was the right thing to do to potentially delay patients to get that total hip replacement, as you mentioned, or potentially to not have that happen and undergo an alternative, such as a hemiarthroplasty.

Yeah, no, absolutely. I think that's like you say, it's, it's that sort of uncertainty, isn't it, about whether that delay is actually going to have effect in these patients? No, I totally agree. And I think that's sort of, Nick, if I could come to you next, it's sort of, you know, there's been a lot of debate and continues to be a lot of debate, I think.

And actually, I think the trends potentially have changed. And when we, when do we use a total hip replacement for these hip fracture patients? And how, how do you feel that's changed over the past, or if it has changed at all over the past few years? And how does that fit with the literature? That's a great question, Andrew, and we're both trained in Edinburgh and kind of, Prof Keaton led the study, look at a randomized trial of hemis versus total hip in, in a very small percentage of patients that are fit, well able, those, those hips, those patients that you would typically see for a total hip replacement.

And we know that the functional outcomes are better for a total hip replacement in that [00:03:00] group ever since their health trials been published in 2019. And there's a systematic review last year by Xavier Griffin, which is struggling to show any functional benefit of a total hip replacement. I think now I'm a consultant and I've dealt with some complications of my own.

Yeah, I think you become a bit more wary of a total hip replacement now. And certainly by definition, this patient's fallen. It's a low energy, often a low energy mechanism. And that patient's frail by definition, they've sustained a frailty fracture, and I think you've got to really pick the patients well before I would offer a total hip replacement to certainly my patient group, but data from the National Hip Fracture Registry in England shows that the percentage of hip replacements went up gradually year on year up until about 2019 whereupon it's kind of came down again.

It's about 20 percent of eligible patients And that's probably due to the results of the the the the health trial and the recent review from Cochrane but the NICE guidelines still state that a [00:04:00] hip replacement should probably be the best procedure for the fittest patients, but it's difficult to define the fittest patients, isn't it?

No, absolutely. I think that's a really nice summary. And I can certainly, in my own practice and what we've seen in Edinburgh as well, is that sort of subtle change. And it does seem to be on being used less. And I think you're right. By the definition of these patient population, they, they have a frailty to them, which is, is, is different, isn't it?

So if we move on to the come back to you, Luke, and sort of move on to the study design, obviously this was a retrospective cohort study utilize patient data from the Scottish Hip Fracture Audit from May, 2016 to December, 2020. So fairly obviously, but just a brief overview of the inclusion exclusion criteria of the patients included.

Yeah, sure. So I think the first thing to say is, so this did just include those patients who are undergoing a total hip replacement for fracture. As for standard inclusion within the audit, this was only patients over the age of 50 and essentially covers any patient being admitted to a hospital across Scotland.

We didn't look specifically as to why people were getting hip replacements, but we would expect the [00:05:00] provision of hip, total hip replacement was kind of consistent with UK practice, which is typically, as we've just kind of talked about. Utilize for a displaced kind of intercapsular fracture where the individual is considered kind of fit and active enough to merit a total hip replacement.

In terms of, you know, obviously this is about a delay. How did you define that delay and non delay group and why? What sort of criteria did you use? Yeah, sure. So delay was defined as surgical management outwith 36 hours of admission. And there was the that specific cut point was chosen because that's consistent with our Scottish standards of care for hip fracture patients standard six.

And this is kind of an evidence based standard and it is largely broadly similar to the kind of accepted standard of care in many, many other countries in terms of, you know, what constitutes you know, an acceptable kind of delay or not. Yeah, absolutely. Absolutely. And in terms of the data available from the, the hip fracture audit and what, what did you, what could you collect and what sort of outcomes did you look at for this [00:06:00] as well?

Well, as, as what we've kind of described a bit above already, we also looked at kind of key demographic perioperative and outcome variables, the outcome variables being survival. So at 30 and 60 days, we looked at early mobilization, readmission, discharge, destination, and length of stay. Okay. Great. I think you kind of mentioned this a bit earlier, but it's important to recognize that this data is kind of collected by highly trained local audit coordinators.

And we typically have really good data completeness of over kind of 95 percent as well. So we're happy that, you know, this is nice, robust data that we're using. Absolutely. Absolutely. I think that's really important when you're looking at any sort of big data set like this. And before we move on to the results, Luke in terms of the analysis you carried out, what just briefly for our listeners.

Yeah, sure. So we'd actually plan to go in with a kind of propensity matching approach between these two groups. But actually, the groups are so well aligned that actually, we didn't need to use that. And therefore, we were able to use this kind of fairly standard kind of t-test for continuous variables [00:07:00] and chi square test for dichotomous outcomes.

We did just a double check the kind of robustness of our assumptions. We did also perform some adjusted analyses as well, incorporating kind of age, sex, prior residence, year of operation, and deprivation too. Yeah, absolutely. Yeah. So I think it's a very robust data set and very, very complete, I think as well.

So in, and that's very clear, the analysis performed. So in terms of the results you, there were 1, 375 patients included overall, just under a third experienced a delayed theatre of greater than 36 hours following their admission. And like you said, there was no significant difference in sort of age, sex, prior residence or deprivation between the two groups.

So what did you, you find in terms of those sort of key clinical outcome measures that you looked at between the two? Well, I think the, the key finding was that there was no significant differences in mortality between the two groups at either the 30 day point or the 60 day point. I think it's also important to note that actually within those two groups, survival overall was very high.

So even at 60 days, it was greater than [00:08:00] 99 percent in both groups, which again is, is very different than what you would see within a normal kind of hip fracture population. There was, however an impact from the kind of surgical delay in terms of a lower rate of early mobilization in the delayed group and that and also a roughly two day kind of longer acute and overall length of stay, which obviously has potential implications as well.

Absolutely. And just before we move on to the cost, we don't know why they were delayed, do we? Is that data available or not? That data is not available. We did exclude patients that had a delay for medical reasons. So we know that this is not, you know, there are obviously circumstances where that that may be applicable, again, probably more likely to impact the more general kind of hip fracture population.

But this is specifically patients that typically either had a delay because, as you mentioned at the start, they were waiting for surgical expertise or just because there was greater prioritization of other cases you know, over over this group. Absolutely. Okay. [00:09:00] And in terms of, maybe Nick, if I come to you, but in terms of costs, what, what was sort of looked at and, and, and, and what were the implications of that, particularly with relation to that length of stay?

So obviously this was registry data. So it's very difficult to do a cost analysis on using this tool, this kind of rule of thumb at best. We know just from previous audit work and cost work that's been done in Scotland for hip fracture patients. It's around £600 a day, but that's going back to about 2000 and Luke can correct me, but I'm sure it's 2014, or, 16.

It's a few years ago when that was done. So that was with the recent inflation rates has probably increased a lot. So for this cohort, I think they came out with something like a million pounds just for those two extra days. Sorry, half a million pounds, sorry, for those two extra days. But there's also, there's also the hidden costs as well, isn't there, like by definition, two extra days, those, those two extra days in that bed, certainly with our current elective problems that we've got and backlog, we could have done a joint replacement or something else in that, in that same footprint.

So there's repercussions outwith just the absolute [00:10:00] cost of, the bed per day's calculation. There's also just the expand a little bit on the cost that they were in a mobilization as well. Like why was it, why was it less on the, if these patients are so fit and so well, and they have the same mortality, why was it less?

Is it because they're having a complication? Is it because they're needing something else? Are they developing a chest infection? I think we alluded to that in the discussion, but, but if they're having some other complications that's stopping them from mobilizing and are we having to spend money, healthcare resources to address them because it delayed time to

and theater. Yeah, absolutely. And that's sort of frames that, that finding really nicely actually. And so if we move on to sort of the implication that sort of leads us nicely into that, you know, I would say this, you know, the strengths and the importance of the study are very clear, you know, it's a very large national audit data study, robust and complete data collection, as we said, carried out by highly trained auditors, along with the sound analysis performed in the paper.

It really highlights that, you know, the operative does not appear to be associated with increased mortality for this, this patient population, but is associated with a longer length of stay and has financial [00:11:00] consequences associated with it. So Nick, maybe stick with you. What, how do you so interpret these findings?

I suppose also, is it what you expected to find? I suppose it is, it was, this was all Luke's work and it was, he's involved me which I'm highly grateful for, but certainly it's, it's a question that never, never really dawned on me, if this fit patient group and whether delay of this group influences mortality.

I, I, I would hate for this paper to be misinterpreted, that patients can just wait for as long as I like for a total hip replacement, because I don't really think that's what, even though that's what it probably suggests from a mortality point of view, we haven't looked at functional outcome, the delay in postoperative mobilization.

We know that in elective patients that leads to poorer outcomes down the line. So, so certainly from that side of things, I'd hate for the pivot to be interpreted along those lines, but I suppose in units whereby there is a delay or, or the service for a total hip replacement might be not as good as in some units.

I suppose this does lend a bit of evidence that we could hang on for a short period of time beyond the 36 hours from admission, [00:12:00] for the correct operation for the correct patient at the correct time. Yeah, absolutely. But it's a difficult question though, isn't it? Even with a functional outcome, stuff that we know, hemiarthroplasty versus a total hip, kind of is.

And then we have to balance. Is it, is it worth a patient waiting over 36 hours to get a total hip replacement when they could have had a hemiarthroplasty? Maybe it's even within 24 hours and they could be open, mobilized and, and that might have benefits that we might miss with a total hip replacement.

I don't know. No, I think that's very true. I think you sort of discussed that nicely in the discussion about, you know, it does raise an important sort of debate about theatre provision and whether you, you know, can you wait for these patients, but then there's the ethical dilemma, you know, they're in pain, there's all the costs.

It's a difficult balance. No, I totally agree. And as you say, with the hemiarthroplasty and the differences between the two, it's, it's debatable. Sort of, Luke, I've come back to you and sort of Nick's alluded to it, but, you know, you know, we've mentioned the clear strengths of the study, but I suppose there any sort of limitations or in hindsight, you know, things you would have done differently with the paper that you want our listeners to know about?

[00:13:00] Yeah, so I think, I think always one of the key things is, as I kind of mentioned earlier, because the survival particularly is so high for this group, obviously teasing out any Differences between the two groups statistically becomes very difficult. I think that was one of the reasons why the kind of confidence interval for the mortality outcomes were quite large.

I think as Nick's mentioned, you know, there are other things that are important within this discussion that we definitely need to be including. And obviously we would have loved to be able to include within the study, but we're just limited by the data that's available within the audit. And I think finally, you know, it is important to remember that, you know, the same as with any observational studies, you know, these findings are association and not causation.

And that obviously, again, has to be taken into account you know, when interpreting the results. Absolutely. I think that's very well put, Luke. And sort of just to finish up, you know, what, what do you think is next here? What, where would you say the future work in this area needs to look at? Yeah. So, I mean, I think, you know, we've already talked, haven't we, about the you know, the current [00:14:00] ongoing debates about the role of kind of total hip replacement for these patients.

I think for me, you know, a lot of the kind of current work has focused on kind of short term kind of outcomes. So I think it'd be really nice to be able to see some longer term kind of outcome data, especially, especially when within this cohort, you know, we're, we're hoping, and we're expecting that, you know, patient's going to live for five, ten years, maybe even longer.

I think also, you know, given the potential kind of rising tide of kind of frailty trauma, I think that it's also important. We continue to really look at this kind of service delivery kind of aspect of things, you know, as this kind of piece of work alludes to, especially when we're working within a financially constrained health service, such as the NHS, because that cost effectiveness of our interventions and understanding each part of the kind of care path.

We, I think again, is, is really important. No, I think that's very well put Luke. I totally agree. Well, both you know, congratulations on an excellent study. I think it's a great addition to the literature in that area. And like Nick's alluded to, I think it's a [00:15:00] question that you maybe not, not everybody always thinks about, but actually is, is, is, has been very nicely answered, I think.

And by the, by the data and thank you so much to both of you for taking the time to join us, it was great to have you with us and to our listeners. We do hope you've enjoyed joining us and we encourage you to share your thoughts and comments through social media, like about what you've listened to today.

And take care, everyone.