Orthopaedic foot and ankle surgeon, Amiethab Aiyer, discusses a study on minimally invasive hallux valgus correction. Watch to learn more about his findings on transverse versus chevron osteotomies.
Hello everyone. My name is Amanda buyer and I'm the chief of the foot and ankle service on the department of orthopedics at johns Hopkins University School of Medicine and today we'll be discussing minimally invasive Alex vargas correction and a study that was done recently by myself and my colleagues back in florida. Actually here are some disclosures of mine, you know, helps Bagosora bunion as it's commonly called is pretty common in the front of the foot and it's actually, it's prevalence that you know, increases with age and it's more common in females. Many patients may complain of shoe wear issues, particularly with pain, pain with shoe wear specifically. And when conservative measures as described here fail. Um surgery surgery is often indicated for these patients, there's multiple surgeries. So if you type in, you know, bunion correction into DR google, you'll find that there's a zillion ways to skin a cat, so to speak. And that involves phony correction, soft tissue correction. Just a handful of ways to actually address this. And as you, as the deformity gets more severe, we usually have to kind of move towards the mid portion of the back of the foot in order to address how severe the deformity is in actuality. And so with this in mind and because you know, more severe deformities may require bigger incisions and the like, you know, the there has been the advent of the minimally invasive techniques that have sort of spanned three different generational ideas. The first of which being, hey, let's just cut the cut. The metatarsal head is seen here where the arrow is kind of delineating and let's just you know try to shift ahead and not put any sort of fixation in there. The second generation is when you know we cut and shift ahead and you know interestingly enough we go ahead and just put a pin into place. And then the third generation probably the more common um the more common and current generation is where we actually cut and shift the head using special tools in the operating room and then actually use screws as you can see here usually 12 and three in order to hold the great toe and an improved position if you will improve alignment both clinically and radiographic Lior on X ray. So there have been you know, multiple studies across the globe trying to better understand what is the clinical significance of doing either minimally invasive versus open procedures. And even in the last in the last year or so. Um including some of my you know, dear friends and colleagues from around the country, you know, the minimally invasive procedures have have been shown to have low complication complication rates decrease in opioid consumption post operatively and overall, you know, pretty good function as a result. And so the what's been studied and the overall results just demonstrate that there's improved postoperative pain, especially in the first week reduced operating room time, blood loss wound healing complications. And this leads to the ability to rehabilitate these patients a little more aggressively, greater patient satisfaction overall and decreased narcotic use. And of course this is sort of a, you know, kind of over not every patient is, you know, every patient is different and that's something you have to be able to discuss with your patients beyond, you know, applying these techniques to them. So the techniques have really been, hey, let's cut the bone either in a vertical fashion or let's actually cut the bone in sort of a V shaped or chevron fashion and doesn't make a difference whether you do a particular type of cut. And that was the basis of our study that we completed. And so we use multiple, you know, categoric specimens and we said that, hey, we're either going to cut it in a straight line as you know, marked out here or we're gonna cut in that V shape and the specimens were thought before we actually completed the relative surgeries on them and they were performed by, they were performed by myself and another foot angle fellowship trained orthopedic surgeon and the techniques and instrumentation were standardized between the two groups. We also looked at how much the head could actually be translated or shifted over if you will. And once that was actually done, the metatarsal base as shown here, was actually kind of potted or locked into place to complete the actual biomechanical testing and failure was defined as whether, you know, we did this kind of loading until failure occurred and that was defined as whether you fractured at the metatarsal head or the activity Osti autumn, the level where the bone was cut or whether or at the level where the screw was actually placed. And all these different biomechanical parameters were as described here were evaluated subsequently. So we had all male cadavers. Uh and the amount of actual shift of the metatarsal head was not statistically significant between the two groups. Either the transverse osteo to me or the chevron or V shaped astronomy group and the way in which they failed didn't differ between the two groups either. Okay. And the biomechanical testing did not show any differences between the two groups either, although when it came to the sort of amount of a maximal both, you know, kind of the amount of load. Um There was some trend, as you can see in both graphs from here to here, there was some trend towards, you know, greater resistance in the transverse group, interestingly enough, two loads to failure with regards to stiffness. This was not statistically significantly different either. And so in conclusion there was no major biomechanical different differences between the two groups. And there was a trend towards an increase your load and the transverse frosty autumn E group, but this was not statistically significant. And so certainly, you know, we might have seen greater values in the transverse cohort as demonstrating the schematics here. In part because of, you know, just the way because of how much bone was being preserved. Um and the fact that we were not able to move the head over nearly as much and so we may have that may have contributed to the relative, you know, differences in biomechanical stability. The you know, the although the transverse Asiata me is typically unstable, it definitely gives you the ability to control for rotation a little bit more easily. Um But the fact that the fact that the amount of cortex that was overlapping in the V. Shaped or chevron group may have actually rendered it weaker because of that reduction in cortical overlap. So certainly there's limitations with any study and a small sample size. Um the specimens did not have a bunion at baseline. And you know, again, a cadaver study may not translate to what we see in the clinical setting. So these are all important considerations, you know, furthermore, because of the nuances just described. You know, it's hard to get the screws to be by cortical fixation, particularly the screw that's closer towards the outside of the more laterally based crew and furthermore tissues that were contracted may have limited our ability to actually translate the metatarsal head interestingly enough. So in conclusion, while minimally invasive surgery is definitely become becoming increasingly popular um it's not without its own sort of risk for complications if you will. And certainly when you're deciding on the type of Asiata me to consider particularly in Alex Valdez correction scenario, uh, you have your choice between either transverse or chevron, but at least in our study, we found that there was no statistically significant differences biomechanically, anyway, between the two Ost Iata me types and certainly should be considered with regards to use in your clinical practice. Here's some references and thank you so very much for your time and your attention.