Episode Transcript
[00:00:03] Speaker A: Welcome to your Cases on Hold, a JBJS podcast hosted by Antonia Chen and Andrew Stonefield.
[00:00:10] Speaker B: Here we discuss the science of each issue of JBJS with an additional dose of entertainment and pop culture.
[00:00:17] Speaker A: Take us with you in the gym, on the commute, or most certainly whenever your case is on.
Welcome back everyone to your Cases on hold. Episode 93, if you are listening, on the day we drop it is November 4th. For the November 5th issue of JBJS, we are enmeshed in the Countdown to 100 or episode 100, 100 episodes of your Cases on Hold.
Can't believe that we're basically finishing our fourth full year of doing these podcasts.
[00:00:56] Speaker B: It's been legit. It's been a good time.
[00:00:59] Speaker A: There have been a lot of changes that have happened, particularly in this year, and even more changes coming up. There'll be a new cover of the journal, new design for the journal starting, I believe, in the next issue.
And also the whole feel and look of the journal, including the way the table of contents is handled, will be changing as well. And as we've mentioned before, in line with that, the number of articles per issue is going to start changing as well. I think this, this article, this issue still has a fair number of articles, but it may be among the last ones that look that way.
So enjoy this and look forward to the new face of JBJS starting in the middle of November with the second issue. As always, the opinions that you hear, regardless of what the issue of the Journal looks like, are mine and Dr. Chen's and not those of the editorial board, the other editors of the other journals in the family of JBGS publications, the Editor in Chief, the Board of trustees, et cetera, et cetera, et cetera.
And this episode of youf Case on Hold is brought to you by the Miller Review Course and JBJS cme.
So while the face of the journal is changing, the high quality educational content that you have come to expect and enjoy remains unchanged. And that includes clinical classroom, that includes the subspecialty examination. So make sure you are accessing that. And that of course also includes the Miller Review course. We didn't do the introductions for our those who have been listening for all 93 episodes you already know. But for those who may be new, I'm Andrew Schoenfeld, Associate Editor, Editor for Methods, and I have with me Antonia.
[00:02:50] Speaker B: Chen, Executive Editor at gbgs.
[00:02:53] Speaker A: All right, so with those introductions out of the way and the necessary caveats said, let's get into the top of the pile. We have what's New in orthopedic rehabilitation by Nakamura permanently free. Then we have quantifying changes in 3Ds tabular morphology and normal hips based on the development of secondary ossification centers by Grewal.
We have spinal fusion in patients with GMFCs 4 or 5 cerebral palsy durable correction and lasting quality of life improvements. 5 year multicenter outcomes by Hariharan. There are three evidence based orthopedic articles in this issue.
We have Hamstring tendon versus bone patellar tendon bone autograph for ACL reconstruction with concurrent lateral extra articular procedure. A systematic review and network meta analysis of randomized controlled trials by Chung and colleagues. We have injection based therapies for the management of hip and knee osteoarthritis by Seah and colleagues. That I'm interested in that article because I don't know is that what's new and exciting in injection based therapies?
[00:04:02] Speaker B: Patients ask for it all the time and they want to know what's out there. So stay on top of things.
[00:04:07] Speaker A: Is nice Hip and Knee Arthroplasty in patients with Obesity by Ko and colleagues. Modern Alignment Strategies until Knee Arthroplasty and How to Best Achieve Them with Harris and colleagues. Are We Choosing and Training the Best Surgeons by Balach and colleagues.
A thought piece then out of left field Leadership Lessons I Didn't See Coming by Jeray that rounds out the other content in the journal will now be moved into the headlines. What's new and exciting in orthopedic research this month?
My article is the Broken Wing Sign, a new Clinical test to Detect Gluteus Medius pathology with and Without Fatty Infiltration by Sierra and colleagues. This is with an infographic and it is 30 days free.
So this is a study in which the authors wanted to introduce a new diagnostic test, clinical examination test that they call the Broken Wing sign.
This investigation normally when you have diagnostic tests, the expectation is that you have an initial study that describes the test or the clinical rationale underpinning the test, maybe with retrospective data and then you look to apply that prospectively.
This study skipped phase one of what you would expect and moved right into sort of phase two. So there's clearly been background work that's been done here and that the authors either present in passing or sort of they present it in a way that they're telling you the background work without showing you the background evidence. Kind of it's sort of like you're not seeing how the sausage is made, but it's clear that that work has already been done.
So really they're trying to do two things at the same time, which, from a methodology standpoint is less than ideal. You want to do the sort of ground or foundational groundwork first, and then you want to present sort of the prospective performance, and we'll talk a little bit more about the ideal ways to do that. Because the way they went about it isn't frankly, the idealized approach either.
But the purpose of this study, per them, was to introduce the broken wing sign, which they say is a novel physical examination designed to detect gluteus medius tears and associated muscle atrophy.
The way this is performed, the patient lies prone on the examination table.
The knee of the tested limb is flexed to 90 degrees. The patient is asked to actively extend the hip against gravity. And then the examiner observes the position of the lower leg in a positive broken wing sign. They say the hip falls into involuntary external rotation, resulting in the foot drifting toward the midline, basically inward.
A positive sign is greater than 10 degrees of external rotation, with greater than 30 degrees considered highly positive for them in quotes in the paper, that might indicate even more severe pathology. But see, this is exactly what I'm talking about. You know, they have these predefined criteria already, and it's just, you know, how did you come up with that? What is the evidence supporting this? 10 degrees versus 30 degrees? They've either done a lot of background work or, you know, a lot of times these types of papers grow out of someone's, like, pet physical exam observation, you know, and by pet, I mean, it's kind of like their own sort of special niche project. It's. They can become like Gollum with the ring and the Lord of the Rings, where they, like, obsess over it all the time.
[00:07:54] Speaker B: And not like the animal. Not their dog, Not.
[00:07:57] Speaker A: Not their dog, but like their. Their special interest project. So these are very specific determinations for an exam finding that is really. This is the first time it's being described. They have, like, these. So I think there's been a lot of. Somebody's been thinking about this for a very long period of time and experimenting and looking at people in the office and looking at imaging, and you're not getting a lot of that background work. It's almost like you're already seeing a finished product that you basically have to. To sort of believe them.
Right? And that's. That's not really what we want to be doing in science. We're just not taking things based on, you know, just trust us. On this. And so then they wanted to apply this in a prospective study. And this prospective study included 59 consecutive patients with 75 hips referred to a specialized hip clinic from December 2022 to February 2025 for suspected hip abductor insufficiency. And that's the first problem right there. That's a. There's a Bayesian phenomenon there, because these individuals are already being referred because they think that something's wrong.
So just the mere fact that they're being referred is going to actually increase the likelihood that there is something wrong. They're not referring these individuals randomly. And 59 patients just doesn't seem like a sufficient number to really model the performance of a novel physical exam maneuver with the depth and breadth of the possible universe of variation that can occur with this type of intrinsic hip pathology.
And so those are two very important problems that we'll touch on later. As far as the results go, the broken wing sign was positive in 49 and negative in 26, which, to me, I was kind of surprised about that, especially since all these patients are being referred to like a specialty clinic with the idea that they already have a problem.
But the MRI confirmed gluteus medius tears in 55 hips consisting of 14 partial, 13 full thickness, and 28 massive tears.
So of the 75 hips, 28 had massive tears.
That's obviously, if you just take the whole universe of patients who have hip pathology or issues with hip pain, you're not going to have 40% of them having massive tears.
And then 20 hips had no tears. And of the hips with full thickness tears, two had fatty infiltration.
And of the hips with massive tears, 20 showed severe infiltration.
So the broken wing sign had high sensitivity, basically 82% and a 92% positive predictive value for detecting any tear.
And then they report 80% specificity, and they do this diagnostic odds ratio, which I don't. I don't think is that useful. Actually, at the end of the day, you know, for diagnostic tests, you want sensitivity, specificity, predictive value. And for massive tears, it had a negative predictive value of 96.1%. So obviously, the authors are invested in really wanting the readership to use this test.
A few things from my standpoint, the first thing is that physical exam tests that are done in the office before you're getting imaging, there's no point in doing them after you have the imaging. If you already know physical exam tests should be highly sensitive. They don't need to be specific. Is for confirmatory tests, negative in the absence of disease is specificity positive in the presence of disease is sensitivity. If you have high sensitivity, that's going to lead you to say, I need to get an mri. So really, screening tests, this is a screening exam. They should have high sensitivity and 82%. I mean, it's, it's good, it's not, it's not great.
And, and I think that's important. You might say, well, it's good. So yeah, but, but this is kind of an idealized population. These are patients who are already being referred for hip issues. You had about, of the, the population, yet about 40% of them had massive tears, major tears. And we've talked about this before with diagnostic test. Diagnostic studies should have three criteria that are met. One, the test of interest is performed in every possible patient to, we're talking about doing the test, like doing the work to support the test. So you have to have a large series of patients in which everyone gets the diagnostic test whether you think they need it or not.
Two, it's compared to an independent gold standard, which in this case you can say is the MRI, except it's only MRIs in patients who are symptomatic. And three, and most important, you have to have the entire representative universe in sufficient numbers of the spectrum of disease from absent all the way to fulminant. So you got to have those massive tears, but you have to have people who don't actually have the condition of interest as well, because there may be individuals who are asymptomatic and have this sign for whatever reason.
This is an idealized population. And for an idealized population, I would maintain 82% sensitivity. Actually isn't that good. And they didn't give you the 95% confidence intervals. This is only 75 hips nested in 59 patients.
As far as describing a new and potentially interesting novel test, I think that's fine.
I don't think that the research supporting its utility and its performance is actually very robust for the reasons that I outline. So I would say that there's room to do this study in a more robust way by ideally, you have a large population of patients with the full spectrum of disease and everyone gets the test in question whether they have hip symptoms or not, and everyone gets an mri. And then you'd have a better understanding about how this test performs.
And you may argue, well, that can't be done. It would be so expensive. Okay, I mean, that's fine. I, I get that, you know, there has to be some pragmatism to this, but at the end of the day, until you do something like that, you're not really going to understand how. How this test truly performs.
[00:14:03] Speaker B: Not much more I can add to that. But we should do it in everyone then.
[00:14:07] Speaker A: Well, yeah, I mean, if you're going to do a test like this and you want to have the tr, you have to do it in the way that I outlined it. There isn't a further workaround, really.
You can't shortcut. You can't shortcut it.
And if you're not going to do it, then you can't say like this test has really high sensitivity or really high specificity because the numbers are likely not going to perform this way.
You can say like it performed well in our population, and you need to look and see if it works in your population. That's probably the best you can do with the evidence that's being presented right now. So let's move into another area of controversy. Mean body mass index does not increase or decrease at 10 years after primary total hip or knee arthroplasty. By.
I would pronounce this Karchevsky or Karchevsky. So I think that's a traditional pronunciation, and we'll go with that. And this is with a commentary and an infographic.
[00:15:08] Speaker B: Do you think people know that pronunciation because of Krzyzewski and the whole Duke basketball team, or do you think people knew how to say that beforehand?
[00:15:15] Speaker A: This is not spelled. As Coach Mike Krzyzewski's last name is. His would. Would, you know, phonetically be Kurzyusk?
K, R, Y.
So, you know, I went to school in New York City in a place where there were a lot of people from Polish families that were very new immigrants to us in Greenpoint, Brooklyn. And my wife's family is also Polish, although they're several generations in the United States.
So we're just plugged into, you know, and. And it's possible that the first author on this paper doesn't pronounce their name that way. Many don't. They. They other. Other ways would be like Karzewski Karla. You know, like people pronounce their names differently. You never know. But I just went with the traditional Polish pronunciation to be safe. You can't fault me for that.
[00:16:06] Speaker B: Nope, don't fault you at all. I actually really appreciate it and like it. So well done. This is a study out of the Mayo Clinic, including, I'm not going to say the name, but also a group of individuals who are interested in weight loss, such as Mike Seward and then Dr. Bedard Dr. Berry and Dr. Abdel, but Dr. Seward has done some work in that space for some time. So it's a interesting study, although you already know the answer. So 10 years after primary total hip or knee arthroplasty, weight doesn't change as a commentary and infographic.
So after joint replacement we typically don't know how patients do long term. You see them, you know, one year, five years, but you don't necessarily see a study on them 10 years afterwards. So previous studies have demonstrated one third lose weight after surgery, 1/3 stay the same, and then 1/3 actually gain weight after surgery. However, these patients are older and don't follow patients again for that long timeframe. So they the purposes of this study were to analyze BMIs up to 10 years after total hip and total knees with factors associated with postoperative changes in bmi. And they hypothesized that on average patients would maintain weight postoperatively. Although some subpopulations might likely have substantial changes in bmi. Now changes can be lower and higher.
There were over almost 19,000 patients, but only ultimately included only 763 primary total joint patients.
310 underwent total hip and 453 who underwent total knees and they went underwent surgery between 2001 and 2011 to allow for the 10 year follow up and had BMIs recorded at surgery and then at 2, 5 and 10 years afterwards through this Mayo registry.
If a patient underwent a second total hip or total knee or arthoplasty for indication other than primary osteoarthritis or they undergoing revision, they were excluded. If they didn't have BMI recorded at surgery and at least one BMI after surgery, they were excluded from analyses.
They did exclude patients who had BMIs less than 15. Sorry, they didn't exclude them. They reviewed them. If you had a bmi less than 15 and greater than 70 and trust me, in Minnesota there are some patients with BMI who are greater than 70. They were reviewed to verify that the values were consistent with other recorded BMI values. If they were incorrect or couldn't be validated, that value was obviously removed. A maximum deviation and timing of one year was used at any follow up point and clinically important weight loss was considered a BMI change of greater than or less than greater than 5% in either direction. The mean patient age was 66 years, 60% of the patients were female and 99% of the patients were white. Because we're in Minnesota, BMI changes were analyzed with repeated measures analysis of variance, multinomial Logistic regression determined predictors of BMI loss of gain of greater than 5% at 10 years was done so after total hips, the mean BMI increased from 30.3 to 30.9 at 2 years and 5 years, so not much 0.6 kg per meter squared. Mean BMI was 30.6 for these patients undergoing THA at 10 years. So right in the middle of it following TKA the mean BMI increased from 32.7 to 33.1, again 0.4 difference at both 2 years and 5 years and at 10 years the mean BMI was 32.6. So actually lower than what they started off with but very similar with regards to statistical significance.
At 10 years, 27% of patients who underwent total hyperthoplasty and 30% of patients who underwent total knee arthroplasty had a BMI decrease of greater than 5%.
That said, 30% of patients who underwent total hip and 32% of patients who underwent a total knee had a BMI increase of greater than 5%.
Although the majority of patients experienced greater than 5% change in their BMI of 10 years, the analysis of change in BMI category over time revealed that most patients remained in the same BMI category post operatively and those that did change categories almost exclusively changed by only one adjacent BMI category. You weren't going from mobile obese to underweight in most of our patient cases, which is probably a healthy thing to do not to lose too much weight or gain too much weight. Changes in BMI occurred in a balanced distribution such that similar proportions of patients gained or lost weight after surgery contributing to a stable mean BMI over time. Each unit increase in BMI at the time of surgery was associated with increased odds of losing greater than 5% of their BMI by 10 years compared with no change in BMI. Female sex compared to compared to male sex had greater than 2 times higher odds of gaining greater than 5% of their BMI by 10 years. For patients who underwent total knee replacements, older patients were less likely to have a greater than 5% BMI increase. So although most patients experience a BMI change of greater than 5% at 10 years, 1/3 above 1/3 below like older studies have shown, the mean BMI did not meaningfully change at two, five or 10 years after total joint replacements. The results were similar to previous studies on this topic. Again, the 1/3, 1/3 1/3 rule. So arthroplasty is not necessarily the way that people should lose weight. Patients are like Doc, I need a knee replacement I need hip replacement so I can lose weight. But female sex and older age may predict weight changes after children, arthroplasty, females more likely to gain weight and older patients less likely to gain weight. Take it for a grain of Salt. Remember, only 793 patients.
Not a high percentage of patients. But then again, they're being followed. 763 patients, but they're being followed up for 10 years. So I commend the authors for doing 10 years. That's a nice thing. But there's a lot more factors to wait than, as you guys all know, than just joint replacement.
[00:21:47] Speaker A: Yeah. So, I mean, let me just pose this to you because this is your wheelhouse, this is what you do. How does this particular study change your practice? And, and I will preface that by don't say, well, we can tell patients that they won't lose weight with their total knee replacement. Because I don't actually think that that's a driving. Like patients are not having their knees replaced because they think it's going to help them lose weight.
[00:22:13] Speaker B: It's very interesting. That depends on the conversation practice. The short answer is no, not necessarily. But I will pay patients who come and says, I've gained a lot of weight because I can't exercise, because my joints. And so once I get this, I'm going to lose weight.
[00:22:27] Speaker A: Right. And then if you tell them, well, I have a research study that says that you won't. What, what does that do for them? Like what, how does that. Right.
I think at the end of the day, all clinical care is, is personal. It's not business.
[00:22:42] Speaker B: It's like, Right.
[00:22:43] Speaker A: So, so it's like, you know, the research nihilist. And I don't encourage research nihilism, but the research nihilist in me will say, every patient is unique. You don't, you cannot tell the patient in the office who says, you know, I'm really motivated, I want to exercise and I can't because of my knee pain. The indication for the surgery per, you know, backing up my previous statement, is to have the knee pain addressed.
And you cannot tell them, well, I know for a fact that you're not going to lose weight. They might be in that. You said it's a third. A third, A third. And we've had literature of this type going back to when I was in residency. There have been studies. Maybe it hasn't been in 763 patients. Maybe it hasn't been 10 years follow up. But if it was in five years follow up and they hadn't lost weight. Now we say, aha. Even double that, they're still not losing weight.
And here's the other thing. Once you get that far out, physiologically, we just know that over time, certainly in the American population, as people age, there's a period of time up to a point where they're actually going to gain weight. How much is different, but there's gonna be a point in time. And then once they get to a certain point, maybe it's around 80 or a little bit older than that, then they actually start to lose weight just as physiologic frailty sets in. So I, you know, the fact that to me, this just, it's. It's too far out to relate anything to. This is just studying patients. I mean, the. As far as I'm concerned, the hip, you know, and this could. This is the Mayo Clinic, right. You have more patients there than just patients who are having total hip and total knee arthroplasties.
[00:24:25] Speaker B: There are.
[00:24:26] Speaker A: Yeah, yeah. There are actually. Yeah, yeah. At your center, too, oddly enough, there are.
There are people who are not just. Right. You could have seen what is it like in the spine patients? What is it like?
What is it like the cardiac patients? What is it like in just the.
The unique thing about the Mayo Clinic is, and why they can do studies like this is that they have a population that's pretty invested in coming to the Mayo Clinic for care and continuing to coming for care. And that's, that's. There's not a lot of flux in, in that population. And maybe as the years go by, that that is changing. But obviously, you know, they have hands on data for individuals from 2001 to 2011.
This was not intentionally done.
This is just the registry at the Mayo Clinic. So tap into your medical records and like, actually show us what other people who don't have hip replacement are doing at the Mayo Clinic. And then maybe we could understand if there's some. But you can't do that with what's being said here. And as far as I'm concerned, it just sounds like the people with the hip and knee arthroplasties are like everybody else and it's the population.
[00:25:37] Speaker B: Right?
[00:25:38] Speaker A: Yeah. Like, I don't understand how.
Well, you know, we found that females are more. So how does that change? And if you're not going to operate on the. I don't like. And these are small numbers at the end of the day, 5%. I mean, again, it's going to depend on what your baseline BMI was. Right. But also when they have the, you know, the older age had lower odds of a greater than 5% BMI increase. But the lower odds, while significant because of the sample size, it's a 5% reduction. And I don't think that's clinically meaningful.
[00:26:11] Speaker B: It's not a lot of pounds. You know, it's there, but it's not that meaningful. As you said, they just.
[00:26:18] Speaker A: Not that much. And actually the odds of it happening is not even that much. It's a 5%.
[00:26:22] Speaker B: It's 5%.
[00:26:23] Speaker A: 5% odds of a 5%.
[00:26:27] Speaker B: Keeps slicing the pie more and more and more.
[00:26:30] Speaker A: Yeah, I, you know, I, I just think the, like, the whole thing is just going on hold for me. The whole, like, the whole concept. I feel like we don't need literature, evidence to tell patients that their perception of an outcome is going to be, because again, you don't know what that individual's, you know, particular motivation, especially nowadays with weight loss with, with the GLP one.
Right.
It's a whole brand new world. And certainly that calls into question when you're studying things from 2001 patients who had surgery from 2001 to 2011. That's not necessarily indicative of what's going on in 2025.
I don't think this provides a nice clinical, historical retrospective of things that happen at the Mayo Clinic.
I don't think it's reflective of anything that I, I don't think it should be used to be informed. Care is, you know, the long and the short of it.
[00:27:26] Speaker B: I think further studies are needed.
[00:27:29] Speaker A: No, no.
Unless there's some kind of clinical ramification. I mean, like, I think there are very few studies in the orthopedic space that support that any of them actually lead to, like, meaningful weight loss, sustained weight loss in patients, because it has nothing to do with, with the, the patient is, is trying to help you help them get a surgery.
You know what I'm saying?
[00:27:55] Speaker B: I do.
[00:27:56] Speaker A: And so if they're having pain and they feel like it's a narrative that's going to help you get them to surgery, then they're going to tell you. Well, I, Yeah. And I don't think that they're lying. I think it's, it's. They're, they're invested in that. And a third.
[00:28:14] Speaker B: A third.
[00:28:14] Speaker A: A third is not. It's not going to happen.
[00:28:17] Speaker B: It's not. I agree. So I agree.
[00:28:21] Speaker A: All right.
So that went on hold, I think, and now we'll see if this is going to go on hold in the actual. Your case is on hold featurette you might have thought we just did it, but no, there's one more to come. So, prophylaxis against complex regional pain syndrome, recurrence with vitamin C and total knee arthroplasty. A propensity score matched analysis of 960, 60 cases. This is by Hernagou and colleagues. This study was looking to see if the use of vitamin C in patients can prevent the development of complex regional pain syndrome after total knee replacement.
So this is a study that was obviously retrospective and it was included patients who had surgery from January 2017 to December 2021.
Now, the authors state, drawing from our clinical observations, we began prescribing oral vitamin C at a dosage of 1 gram daily for a period of 40 days following surgery starting in 2018 for, I guess, select patients, as they said from our clinical observations. And they cite three studies, references 6, 7, and 11.
And this is, this is one of, like, my, you know, recommendations to people who are learning how to craft literature and learning how to write literature. And I think it, you know, I mean, it's for people who are learning, but it's for seasoned people as well.
That's something that you should actually, like, spell it out. Like, you should spell out your educations. Don't make people go look up an article or three articles to figure out what it is that you're talking about. And they might read the article and, and still not have, you know, maybe it says plain as day, there are three articles there. So I don't know if it says the same thing in all three articles. But why couldn't you just write like, these were our indications for using vitamin C, then we wouldn't have to. You could still cite the literature, like, cite the literature that supports what you're saying, but don't make someone do extra work to figure out what it is that you're doing.
And then also don't leave any ambiguity in. Because I could read those articles and maybe think I know, but I'm not even sure because you, you could just.
[00:30:32] Speaker B: Tell me how many people think actually look it up.
[00:30:34] Speaker A: I, I don't know. I don't know how many people actually look it up. I mean, to understand this, to understand the study truly, I think you have to look it up.
[00:30:42] Speaker B: No, I said you mean. Yep, that's true if you want to really understand the study. True.
[00:30:46] Speaker A: And, but maybe you won't. Even if you do look it up, maybe you think you, you do understand, but maybe those aren't completely spelled out or one thing says one thing and the other thing says something else, so you still might not know. But essentially this is a causal inference investigation. And they want to use propensity score matching because there was a confounding by indication, that much is clear. They have certain patients that are getting vitamin C and that's somewhat intentional as compared to others who weren't. And we're at a little bit of an unknown about who has it and who doesn't.
So they want to use propensity score matching ostensibly to control for that confounding bite indication.
So they had 488 patients with vitamin C prophylaxis and 550 without it. And in that group they have 49 patients who had a history of complex regional pain syndrome before the surgery.
Now electively, I don't indicate patients for surgery if they have complex regional pain syndrome. Now I work in spine obviously, but.
[00:31:55] Speaker B: I would think that everyone has complex regional pain syndrome.
[00:32:00] Speaker A: What, in spine?
[00:32:02] Speaker B: I'm just joking.
[00:32:05] Speaker A: But you know, I mean patients with complex regional pain syndrome, the likelihood of them having issues after an elective surgery is actually really quite high.
But obviously, you know, There are only 49 patients with diagnosed CRPS prior to their knee surgeries. And they were, they gave an order of magnitude more patients the vitamin C anyway. So there were other people that they thought were potentially at high risk.
And so 37% of the 49 patients with a history of CRPS actually also then had CRPS again.
And that's another thing that I can't really is like CRPS is not something that like you don't get cured from it, like you manage it. So you know, maybe they had a flare up afterwards, but it's not like they got it again. You know, it's not like Covid like you, you got covet again or you got strep throat again. It's like if you have CRPs, you.
[00:33:00] Speaker B: Have it, you have it, it does not go anywhere else.
[00:33:02] Speaker A: Right.
And so then there were 101 new patients in the cohort, 10.2% of the cohort that didn't previously have CRPS that then developed it, which seems like super high. 10% of patients undergoing knee arthroplasty develop CRPS.
Does that like, does that ring true to you? Like, do you have 10% of your patients who are developing CRPS after knee replacement?
[00:33:30] Speaker B: I don't think so, but I'm going to be honest. Right, the formal diet.
[00:33:36] Speaker A: 10 out of every 100, that's a lot.
[00:33:38] Speaker B: That would be a very painful post operative clinic for Me to see patients like that?
[00:33:43] Speaker A: Yeah, I mean, that's like basically, you know, one out of every 10 post ops. No, I, I can't. And this is CRPS diagnosed by the Budapest criteria. So there are specific outline parameters for these patients to develop complex regional pain syndrome.
And the issue there is that this is not just like somebody who has like a lot of pain after their knee replacement. They met criteria, they met the changes in the hair and the vascular sort of phenomena or combinations thereof.
So these are not just fly by night, like, oh, they had chronic pain. We'll say they have CRPs, or we're not really sure what's going on with them, we'll just call it crps.
And I'm not saying that to indicate that there is something wrong with their diagnostic approach.
I'm saying that because my contention is that this is a high risk population at baseline and that's why they have this cohort of patients that is getting the vitamin C, because they were already suspicious that this population was at a higher risk.
And that's part of the issue at hand.
So based on whether they got vitamin C or not, they had 7% CRPs in the vitamin C group and 11% in the non vitamin C group.
And they want to study this further by doing the propensity score matching.
So ideally, a causal inference test or causal inference study is supposed to replicate the randomized controlled trial, in which case you have the patients who are randomized to vitamin C and those who are not Vitamin C doesn't seem to me to be a high risk intervention. I think this study is probably best done as a randomized trial.
Use propensity score matching. When you say, like, you know, the outcome is too rare or the risks are too high or there's not clinical equipoise, there are all sorts of reasons to do propensity score matching and to replicate the environment of an RCT when an RCT is not possible. But I think an RCT is possible in this context.
But if you just. Coming back to the propensity score matching, if you're going to do it, you want to do it by using the adjudication of how did you define like, you want to find the same characteristics in the patients who didn't get vitamin C.
And I don't think that they did that they developed a propensity score based on sex, age, bmi, presence of diabetes, hypertension, use of tobacco and alcohol, anesthesia, modality, tourniquet use, anxiety and depression. Now, while some of those like anxiety and depression and maybe Tobacco, alcohol use or certain, you know, maybe some of those parameters do play into, oh, we think this patient may be at higher risk for CRPs. I don't think that anesthesia modality plays into it, probably, or tourniquet use necessarily, but you should have a proof, like you should study the factors or include the factors. You should show those factors as being associated with the decision for vitamins. And, and then that's how you build your propensity score. And then the expectation is that the propensity score should have a caliper that's conservative at 0.1, not 0.2, which is what they use, which is a very permissive caliper. And then on top of that they're layering logistic regression analyses, which is not a best practice. So there's some methodologic concerns here as well.
Ultimately, they did find that even after adjusting for everything, that vitamin C prophylaxis may be appropriate for preventing CRPs.
At the end of the day, I think they could have done this study without the PSM and the conclusions would probably be the same.
You don't have, there's not added value or added validity from the PSM approach here. It's basically just replacing a logistic regression analysis. I think that this concept holds promise potentially, but needs to be studied in, in a more robust way. You're going to start giving patients vitamin C before. I mean, like, it's such a, it's such a low risk intervention. Just, you know, it's a water soluble vitamin. Just give everybody vitamin C before maybe, period.
[00:38:02] Speaker B: Right. That's the benefit of it. It is so benign in its treatment that it's not a bad thing per se. But I would love to develop some real algorithms as to who would get it, who wouldn't, and if it would really make a big difference. It just adds to the controversy of the vitamin C literature. I would say some literature supports this, some literature doesn't support it. It's kind of all over the place. But to your point, this is where a prospective randomized controlled trial is actually very helpful. And that can really discern whether or not you're doing this in a biased patient population as opposed to a, you know, less biased patient population.
[00:38:33] Speaker A: And you don't have to take our word for it, it is 30 days free, so check it out yourself within the next 30 days.
All right, so moving into the honorable mentions, we have psychometric properties and feasibility of PROMIS computerized adaptive tests compared with disease specific measures and knee arthroplasty by Dollender and colleagues with a visual summary and also permanently free.
This study included 193 patients who looked at precision and percentage of the scale range, responsiveness, floor and ceiling effects of Promise Picat and Promise pfcat along with other measures. It's almost like a litany of word letter soup here. Kuz Womack scales and the Koo's P.S.
koos Jr. Of course makes an appearance.
Couldn't have a study without Cruise Jr.
Essentially they're saying that promiscats effectively assess health outcomes in knee arthroplasty patients showing strong psychometric properties and favorable feasibility supporting their role in value based health care. This is a Level 2 study per the authors.
Next we have a novel easy to measure radiographic parameter to assess spinal pelvic malalignment, the pelvic inclination angle by park and colleagues. This study studied this pelvic inclination angle in 162 patients with a mean age of 71.1.
They indicate that this angle reflects symptom severity and had a normal value independent of the pelvic incidence.
As an alternative to pelvic tilt, this study can be a clinically useful parameter given that it's independent of PI. It's more useful in differentiating between between patients with normal spinal pelvic alignment and those with misalignment or malalignment in reflecting clinical symptoms. In addition, they do provide a cutoff value. I'm not sure how valid that's really going to be or how robust it will be given that they only have, you know, they have less. They have about 150 patients then we have congenital cervical scoliosis at the cranial vertebral junction. Clinical characteristics and surgical strategies in 27 patients with midterm 5 follow up by Ty and colleagues Obviously this is just a rote clinical retrospective of the author's experience with 27 patients in this very unusual clinical condition. Congenital cervical scoliosis at the craniocervical vertebral junction and this is a complex deformity, severely impacts coronal alignment and they are showing what their tailored surgical strategies and experiences are. Obviously there's huge concern for expertise bias in this context, but interesting information.
Very limited series, but it's not an especially common condition. Of course that is about it for us in this episode. We are about out of time. We'll try to do better next time. Thank you for those who stuck with us the full way. If you like what you heard, like and subscribe, share with others, you can find us on Casto Stitcher Apple, Spotify, Amazon, or short of that, go to JB J. S I think on YouTube as well. If you didn't like what you heard, then come back. Next time listen to what Dr. Chen says. As we get even closer to the 100th episode of your cases on hold, hopefully where you are, your cases are ready to go.
But here, as I think was the case for all three main articles we covered, those cases are still on hold.
Nothing going to the OR today.
[00:42:29] Speaker B: No surgery for you.
