A Fracture Healing Odyssey

[00:00:02] Speaker A: Welcome to your Case Is on Hold, the JVGS podcast, hosted by Andrew Schoenfeld and Aisha Adkeen. [00:00:08] Speaker B: Here we discuss the best of what each issue of JBJS has to offer with the usual dose of entertainment and pop culture. [00:00:16] Speaker A: Take us with you in the gym, on the commute, and as ever, whenever your case is on hold. [00:00:26] Speaker B: Welcome back to another episode of youf Case Is on hold, episode number 116. If you are listening, on the day we drop, it's October 20th for the October 21st episode and it is almost Halloween, so I hope you're getting your candy stock and your scariest costumes ready. My name is Aisha Abdeen. I'm Chief of the Division of Hip and Knee Arthroplasty at Boston Medical center and Associate professor of Orthopedics at Boston University, and I have with me, as [00:00:52] Speaker A: usual, I am Andrew Schoenfeld, professor of Orthopedic Surgery and Vice Chair of Education for Harvard Medical School. [00:01:00] Speaker B: As a reminder, the opinions expressed here are exclusively our own and do not represent those of jbjs, the editorial board, the Board of Directors, nor the affiliate journals of jbjs. This episode of your Case is on hold is brought to you by the JBJS Clinical Classroom, a platform to support you in your clinical practice, lifelong learning, exam prep, and continuing education from med school to practice. So no matter what stage of your training or career you're in, there is something here for everyone that you can tailor to your own learning needs. So without any further delay, we'll get to the top of the pile on this issue of jbjs. So lots of good stuff in store for you today. What's New in Shoulder and Elbow Surgery by Rao It's Permanently free More Signal, Less Noise Enhancing the Methodological Rigor and Clinical Utility of Orthopedic Aggregated Real World Data Research by Bank Total Joint Arthroplasty during Ramadan Perioperative Implications for Patients and Surgeons by Siddiqi the Strength of the Splint A Lesson in Buddy Taping by Kadiala and It's Permanently Free Shaping Modern Practice in South Korea A Centennial Review of Orthopedics at Severance Hospital and Yonsei University College of Medicine by Jung the Role of Biologic Age in Adult Spine Deformity Surgery by Salazar Changes in the Management of Periprosthetic Joint Infection over the past 50 years by Abiti now for our headlines, we'll have Andrew start us off with A Fracture Healing Odyssey Kinematic Comparison of Unions and Non Unions in Human lower extremity long bones treated with intramedullary nailing. A retrospective cohort study by Lopez. There is a commentary, an infographic highlight, and it's permanently free. [00:02:50] Speaker A: Yes. So I actually think the premise for this study is very interesting. I don't usually love journalistic titles. I don't know if they were kind of going with the Odyssey, as in the new release of the movie the Odyssey. [00:03:06] Speaker B: That was my take. [00:03:07] Speaker A: Yeah. Which would be timely. I don't know when exactly this was submitted or accepted. It was epubbed in May, so I guess they could have been aware when it was, when that movie was coming out or when there was like a lot of hype around it. Or maybe they're just referring back to the classic Homer's Odyssey. You obviously don't need a movie to have that in your memory bank, of course, but I don't really understand how it relates to the Odyssey in and of itself. Spoiler alert. I do actually like the study. I think the study is very interesting and I think that there's a lot of novel concepts that it brings to light and things that really have tangential tendrils that infiltrate and suggest studies in other aspects of orthopedics. So I really enjoyed it on that front. But it's like if you just took away the first four words and got rid of the colon and just started with kinetic comparisons of unions and non unions in human lower extremity long bones treated with intramedullary nailing, that would have done just as well. We didn't need the a fracture healing odyssey that. I'm still not sure how it totally ties in, but the goal of the study was to evaluate whether a logistic statistical model of radiographic healing scores over time could quantify differences between fractures that healed and those that went on to non union. And that's another thing that people who have been listening to us for a while will know. I don't love backgrounds and motivational premises that rely on. We've got this new kind of statistical model that we're going to apply to this. Right? Like the. You use the statistical model that's appropriate as a tool to address the study question. But I think that's a little bit of a feature and not so much of a bug here because it really is wanting to see that there are kind of different trajectories that patients are going to take. Those who are going to successfully heal, maybe some of those that you didn't think would heal that do. Some that you thought would heal don't and where do those two populations start to diverge and why? And that's ultimately what they're trying to get at. So they had 613 fractures, 234 tibial, of which 38 were nonunion, and 379 femoral, of which 49 were nonunion. And they actually had a recent study that was looking at or pitched this logistic parametric statistical model. I feel like the introduction could have gone into this in a little bit more accessible detail. It's very technically dense, I think, but basically they want to understand the healing kinematics, just as I outlined it for you. They use de identified radiographs from four previously published cohorts, supplemented by some additional patients with rust and MRUST scores that were plotted over time for each of the fractures and a 4 parameter logistic curve to sort of identify where those divergent trajectories may start to show themselves. And then they calculate the rate of healing over time and the change in the rate of healing. And there's a lot of mathematical modeling and all sorts of algorithms that are shown and different equations that are presented. Again, probably could have been a little bit more accessible for the clinical end user than it actually comes through at the end of the day. But they had a total of about 2,055 scores across all their fractures. 17% of the femoral fracture scores and 32% of the tibial fracture scores were recorded in the first four weeks following the index surgery. Then they make a lot of different comparisons, and except for just one of them, all the parameters were different between the healed fractures and the non unions. So relying on their previous work, which they say focused on femoral fractures, they didn't know if it would be effective for the tibia and if it can distinguish between different healing trajectories. But they're modeling healing as a continuous process and they're basically looking to find where that person is along that temporal trend. They believe this approach provides deeper insight into the kinematics of healing. They don't intend it as a predictive tool. They say they don't intend it as a predictive tool. I'm not sure how else you would really use it though. And they really find that, as is true, a lot of earlier work that has been done in this space has limited consensus because the definition of what's non union and what isn't is in and of itself kind of a moving goalpost at times. And there's a lot of application of that term to different phenotypes that therefore result in A lack of translational capacity. So they, they really believe that. And what they're trying to advocate is that they want to focus on the journey rather than the destination, they say, which I think does make sense. It isn't temporally based, it's just based on the trajectory and, and the change in terms of both the, as they call it, the velocity and the acceleration toward healing. And they believe that the data may help to contextualize early post operative radiographs when they're obtained. But again, it's not designed to define optimal post operative imaging times and they don't by themselves justify changing current follow up imaging practices. So they have quite a few caveats at the end. And their summary conclusion is that this is a proof of concept demonstrating that modeling of radiographic scores can quantify differences in healing between femoral and tibial shaft fractures treated with IM nails that will go on to union versus nonunion. So it's possible through this algorithm to identify who's on the right path and who isn't. But it isn't possible necessarily to say that what they have here with essentially 87 non unions between the tibial and femoral is translational or generalizable to other clinical contexts. I think it's a very interesting and well done technically study that is, as they say in the end, a proof of concept. I think there are lots of other things that you could look at, you know, healing of spine fusions, recovery from surgeries that use the same kind of model to identify who are the people that are really going to make it quickly or make it fully and those that would go on to other types of non union or complications or things like that. So I really like it because it is introducing a concept that I think has a lot of broad applicability in other domains. And as long as you have a sample that's robust enough with outcomes that are well defined, I think this technique could be applied in other areas. [00:10:09] Speaker B: Yeah, well put. I agree. I don't have anything to contest there. And I think this on hold or not on hold? Pretty clearly not on hold. [00:10:16] Speaker A: No, no, no, definitely not on hold. [00:10:19] Speaker B: Terrific. Let's get to my headline. I'm going to discuss a paper entitled Comparative analysis of Immune Cell Type Abundances in Periprosthetic Tissues across Arthroplasty Failure Etiologies, Use of transcriptomic deconvolution, and this is by Li and colleagues. This study was performed in the People's Republic of China. The authors investigated a contemporary technique for the diagnosis of PJI given that PJI is the most common mode of failure of total joint arthroplasty and despite diagnostic paradigms it remains difficult to differentiate septic from aseptic failure and there remains a need for methods to understand the cellular mechanisms that distinguish septic from aseptic failure in total joint arthroplasty. This study evaluated cybersort joint are at tx, which is a transcriptionomics based cellular deconvolution technique. This sounds pretty complex and the first thing I thought of in PJI is how we need more complexity in the diagnosis of this problem, but deconvolution is a simplification of a complex signal. This technique allows for the inference of immune cell composition from bulk RNA sequence data and the computational approach provides a unique opportunity to systematically profile and compare immune cell landscapes of periprosthetic tissues across different arthroplasty failure conditions. The aim of the study was to analyze transcriptomic profiles of periprosthetic tissues using this technology. It was a single center retrospective study performed between February 2023 and May 2024. Surgeries were revision and DARE procedures performed by a single surgeon in 185 cases, including 135 PJI cases and 50 what they called aseptic failures. Periprosthetic tissues demonstrated the most characteristic inflammatory features were collected from three distinct anatomical sites, immediately snap frozen in liquid nitrogen and subsequently stored at -80 degrees Celsius. All periprosthetic tissues of each patient were pooled together prior to RNA extraction and sequencing. Synovial fluid, periprosthetic tissue and fluid from the sonication of the prosthesis were used to diagnose pji. The samples underwent a process called cellular deconvolution whereby RNA extraction and sequencing was performed and raw gene level count data from RNA sequencing was filtered to remove low abundance artifacts. The data was then converted to transcripts per million and exported for deconvolution. This was performed with non log transformed TPM values using the Cybersort TX web application. The correction was enabled and absolute abundance was estimated using 500 permutations and for each sample. The predicted relative abundance of each cell fraction was calculated by dividing its deconvolution global p value. P value of you know more than 0.05 was excluded leaving 185 samples for downstream analysis. The diagnostic performance was calculated was evaluated using receiver operated operating characteristic or ROC curves and area under the curve SO aucs and the fractional cellular abundances in the cellularity profiles differed between PJI and AF cases so six of the 22 evaluated immune cell types including plasma cells, resting memory, CD4T cells, CD8T cells, activated mast cells, monocytes and M1 macrophages were all elevated in PGI cases after controlling for the false discovery rate using what's called the Benjamin Hochberg, which was new to me procedure. Five of these plasma cells, resting memory, CD4T cells, CD8T cells, activated mast cells and M1 macrophages remain significant in the aseptic failure samples. Only one combined immune cell population, the total macrophages and monocytes, was elevated both before and after the BH correction. So Kaplan Meier analysis for all patients with PJI revealed a mean two year survivorship free from infection recurrence in 88.8% of patients with a CD8 Treg ratio above the median and had a significantly better infection free survivorship than those below the median. So the CD8 Treg ratio, it's something that compares the amount of killer T cells or the CD8 cells to suppress the regulatory T cells or the Tregs in a tissue. And a higher ratio often points to a stronger immune system that basically checked out that that was predictive of better survival. For the case with pji, Kaplan Meier analyses for all other individual immune cell types combined populations, immune cell ratios showed no significant association with infection recurrence. So, you know, I thought the study was well conducted. However, there were, you know, very limited aseptic failure samples, only 50 samples in comparison to the PGI failures of which there were 135. And aseptic failure can be better, very heterogeneous. And they didn't sort of characterize, you know, the aseptic failures. It could be from loosening, in which case there would be macrophage responses. It could be from stiffness, in which case the immune profile might be very different. Could also be from dislocation, other mechanical problems. So to lump all of those together may cause some variation and some bias. And additionally the PGI groups were not distinguished based upon pathogen, which may also affect the type of immune cell response. So I think a broader sample and longer term survival would be needed to sort of really determine the effect particularly of the CD8 Treg ratio on infection free survival because they had short term follow up at two years. The other issue is we don't know much about the patients. What were the demographics? They said it was all arthroplasty, so DARE procedures and revisions, but they didn't specify whether it was hip or knee or even shoulder were included. It wasn't clear to me what prostheses were included or excluded. And we know that different implants have different infection profiles, particularly shoulder might have P acnes and less sort of virulent organisms that may not sort of elicit the same type of immune profile and responses. So those are just some questions I had. But you know, all in all I thought this was a really interesting topic and very novel. So not on hold for me. But interested in hearing your thoughts. [00:16:46] Speaker A: Yes, definitely not on hold. I agree with all the points that you raised. Very interesting from a novelty and potential impact as their clinical relevance statement highlights. It is hypothesis generating for all the reasons that you said. I do think the CD8 Treg ratio is an interesting finding that bears further testing. My biggest concern was as you articulated in and with respect to the clinical variation extant in their 50 aseptic failures of which there probably is not very much, and then even within the 185 PG or 135 PJI samples for diagnostic study performance you really want an ideal spectrum from low virulence to fulminant, different bacteria types, different clinical presentations and maybe admittedly as a basic science study, this particular investigation wasn't set up to do that. But that is a necessary and probably next immediate step in the process to really define the clinical utility and applicability of this new test. [00:18:06] Speaker B: So now for our your case is on hold featurette. So this paper is entitled Long term outcomes after Arthroscopically Assisted Latissimus Dorsi Tendon Transfer for Irreparable Posterior Superior Rotator Cuff Tears Assessment and a minimum of 10 year follow up by Beck. There's a commentary. It's the lead article and it is 30 days free. Essentially Arthroscopic assisted LAT Dorsi transfer. It offers a joint preserving option. The authors essentially looked at their 10 year follow up to determine what the longer term outcomes would be for this minimally invasive technique for a very difficult problem which is massive rotator cuff tears. They cite that the data for open repair as it was originally described by Gerber and Associates in 1988 which is indicated for irreparable tears of the supraspinatus and infraspinatus with an intact or repairable subscap. So the transfer of the LAT dorsi to the greater tuberosity, restores external rotation and humeral head stabilization and in shoulders with minimal arthritis and adequate muscle quality led to excellent short term outcomes. Gerber's group found that at mean of 12 year follow up patients with mild osteoarthritis progression had very good outcomes and there was a low progression to osteoarthritis in this cohort. This group retrospectively analyzed 33 shoulders and 33 patients. The mean age was 62 years, slight majority of male patients, all ethnic Korean patients and they had arthroscopically assisted Lat Dorsi transfers. The clinical assessment showed a range of motion and constant merly the American shoulder and elbow surgeons or the ASES score and VAS pain scores and they looked at osteoarthritis progression which was assessed radiographically using the Hemato classification. They looked at their outcomes, specifically complications, reoperations, specifically looking at the reverse total shoulder arthroplasty or patients that had gone on to a reverse shoulder and they noted that there was a significant improvement in the functional outcome scores. So the constant Merli score increased from 48.2 to 62.7 and the ASES scores also increased for elevation increased and the mean hemata grade increased from 1.2 to 2.4. So the inclusion criteria were hemata grade 1 and 2. So they didn't include patients with more advanced arthritis from the outset and they only had progression in a small portion to grade three or higher. On Mr. Imaging final follow up they found that 58% of the transfers remained intact and 42% had a full thickness retear. They found that the outcomes were similar between patients with and without arthritis progression, but patients with an intact transfer had better forward elevation external rotation. In addition, late subscap tears occurred in 30% of patients which were 10 shoulders and were associated with preoperative grade 2 fatty infiltration. In summary, the authors conclude that this is a technique that does relieve pain and function for patients with massive irreparable posterior rotator cuff tears. Despite the fact that there is radiographic progression, the clinical outcomes remained favorable and they do recommend this, particularly in younger patients with minimal arthritis. At the outset I thought this was interesting. They give some very good detailed technique instructions of how they perform the operation and I think that's very helpful. They also I think they could have given a little bit more of a broader explanation of other types of reconstruction in their introduction and their discussion. So it made it sound as though this is a very unique patient population. It seems like this operation is done pretty widespread, but there are other techniques for these irreparable tears including superior capsular reconstructions. And so I think they could have included a little bit more in their discussion of how this technique compares to other options. But overall it's a long follow up of a body of literature that's sometimes hard to get follow up as we saw from the previous episode or issue this month, that to get long term follow up on shoulder surgeries past two years can be difficult. And so they did have a large body of follow up at 10 years and were able to capture the patient reported outcomes in a very robust manner. So I think overall a very well designed study and it gives us information on this particular technique for a very difficult problem. And so I'd be interested in hearing your take on this. [00:22:56] Speaker A: Yes, I agree again with all the points that you raised. Very difficult and a rare procedure that we're getting this natural history in the context of their rote clinical retrospective for patients who had minimum tenure follow up which is outstanding. It is just 33 patients. So there is a restricted clinical variation on that front that is unlikely to hold up in other contexts or across other samples. I just illustrate this with the findings that they had event rates and certain secondary outcomes. There were no nerve related complications. So do this enough, there'll probably be one just sort of due to chance. What I would encourage authors who in the future and what wasn't done here, but what I would like to see, if you're going to give us your rote clinical retrospective over 10 years, 15 years, 20 years, do the 95% confidence intervals around the point estimates because that will help sort of give a better range in terms of what someone might expect. You know, for example, they say two shoulders, 6%. Well, that 6% is going to be centered on a range that might be 1 to 25% or something like that. So that can give some people a better understanding. It's unlikely to be 6% after 6%. After 6% in every context there's going to be a range and those figures just based on the number are not going to be especially precise. I also, you know, when reading these types of studies I'm reminded of like the infomercials where they'll like show you like the individuals, you know, oh, I'm, you know, I've got this great experience and then it'll stay at the bottom in like tiny fine print. Like results not typical. Like there's, there's no need to qualify the things. I think it's like give us the results. Don't, don't give us a quality opinion. So they say shoulders with progression. And there was a lot of progression. There were 12 patients out of 33. They showed similar scores in range of motion. They had acceptable, what do they Call it. They say despite frequent radiographic osteoarthritis progression, clinical outcomes remained favorable. What is favorable? Favorable is a quality like that is a term. [00:25:36] Speaker B: Yes. Right. [00:25:38] Speaker A: And then just, just tell us that for those who had osteoarthritis the HD values were 8. For the others it was 4. And that was statistically significantly different. Like. [00:25:48] Speaker B: Right, don't editorialize. [00:25:50] Speaker A: Right. [00:25:50] Speaker B: The data. [00:25:51] Speaker A: Yeah, [00:25:55] Speaker B: I agree. [00:25:56] Speaker A: That's about what I have on on this one. [00:25:59] Speaker B: Very good. Okay. And now we will get to our honorable mentions. So first we have pyrotitin pyrocarbon shoulder hemiarthroplasty clinical and radiographic outcomes with medium term follow up by Hoy and colleagues. There is a commentary and it is permanently free. So pyrocarbon hemiarthoplasty or HA is a recent option for younger patients with end stage feno humeral arthritis. The aim of this study was to evaluate medium term clinical and radiographic outcomes following Pyrotitan Pyrocarbon HA. The authors included 119 shoulders with glenohumeral joint arthritis in 115 patients. The mean age was 50 56.5 years old and the patients underwent the Pyrotitan Pyrocarbon HA. Primary patient reported outcomes or the PROMS included the Western Ontario Osteoarthritis of the Shoulder Index and the American Shoulder and Elbow Surgeon Score. Clinical assessed shoulder range of motion. Abductor strength was also included. PROMS and clinical evaluations were recorded preoperatively and at 6, 12, 24 months and 5 years post op. Post op complications were recorded. The authors found that there was significant improvement in all PROMS and range of motion at 6, 12 and 24 months and at 5 years postoperatively abduction strength was significantly improved. At 24 months there were 5.9% of patients had complications. In 7 patients there were ongoing pain in 2, stiffness in 2, pain and stiffness in 2 more patients and an implant fracture in 1. There were 3 revisions and a 97.55 year survival rate. Glenoid erosion increased slightly but not significantly over time and the authors conclude that the findings support the use of the pyrotitan HA implant as a viable option glenohumeral joint arthritis across a broad age range including younger patients. Our next honorable mention is entitled Radiographic Measurement of Psoas Muscle Width A Simple and Reliable Screening Tool for Sarcopenia by Katoka. There's a commentary, a highlight, a visual summary and it is 30 days free sarcopenia, which is the Progressive loss of skeletal muscle and mass is associated with adverse outcomes including increased post op complications in patients with orthopedic conditions. Connecticut and magnetic resonance imaging remain the gold standard modalities for assessing sarcopenia, but cost, radiation exposure and limited availability restrict widespread screening. This particular study investigated the potential of lumbar spine radiographs as a practical alternative for sarcopenia screening. They retrospectively reviewed data of patients who underwent surgery for degenerative lumbar spine diseases and had both preoperative standing and lumbar spine radiographs and supine CT scans. The sarcopenia was defined on the basis of previously established psoas muscle index thresholds and inter observer reliability was assessed with the interclass correlation coefficient or the ICC. They had 305 patients with a median age of 71.7 years. The patients were classified as having sarcopenia in 114 patients or 37.4% and radiographic psoas muscle width demonstrated excellent inter observer reliability and strongly correlated with the CT measured psoas muscle area. Multivariable analysis identified the psoas width as a significant predictor of the psoas muscle area. So in conclusion, the authors found that radiographic psoas muscle width measurement is a simple and reliable method for sarcopenia screening that may facilitate early sarcopenia identification, enabling timely intervention and improving surgical outcome predictions. Lumbar spine radiographs hold potential as a novel screening tool for sarcopenia beyond their conventional diagnostic role. So there you have it, all of the spooky data for this October issue of jbjs. Hopefully by now your anesthesia team is ready to go and your case is no longer on hold. We hope you like what you heard and if you did, please drop us a five star review on Apple or Spotify or wherever you get your podcast. Take care everyone. [00:30:13] Speaker A: Sam.