Refining Techniques and Avoiding Problems With MIS for Bunions
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Transcript
Tyler Gonzalez, MD, MBA, FAAOS: Yeah. And so you guys have mentioned a lot of good technique, shifting a hundred percent, the metatarsal adductus, understanding the reduction. But let's, let's dive into that just a little more. One thing you mentioned, Dr. Schipper, was heat generation. You know, Dr. Loder, are there things you do to minimize, you know, people are very worried about the burr, they're worried about skin necrosis, they're worried about avascular necrosis of the bone. What has your experience been with thermal necrosis of the skin, thermal necrosis of the bone, as well as non-unions. What's kind of been your experience with that? Because I think a lot of people are concerned about this burr and causing trouble.
Brian Loder, DPM, CWS, FACFAS: Yeah, so, you know, I'm 100% burr, and so the non-union rate of a chevron or a transverse osteotomy is so small. I mean, I think I've had two in in approaching 800 procedures. It's small, very, very small. Originally, I used a tourniquet. I stopped using a tourniquet, which helps cool down a little bit. I also think that, yeah, you should be using cool saline or saline like Oliver published, especially when you are starting out because you tend to linger with the burr a little bit too long. But as you become more and more experienced, the amount of time I spend in the osteotomy is literally within seconds. It's so quick and so smooth. So just a little bit of saline and it's done. So that reduces the skin necrosis from the burr and that also reduces the necrosis at the bone.
Dr. Gonzalez: Oliver, any other tips or tricks you have for avoiding heat necrosis of the skin or the bone and your experience with non-union and actually thermal injury using the burr?
Oliver Schipper, MD: Sure, so I mean, I agree with everything Brian said if I had made a bunch of great points there, a couple small points I'd add. So when you're new to MIS, right, heat is the enemy and we use the burr initially, you'll probably generate a little more heat that you would if you were experienced, because again, you're learning how to use it. And so when we first started doing MIS, the majority of the handpieces had this very small fine spout of irrigation. Most of the time, it wasn't really even hitting the incision. Again, it was a very minimal amount of fluid that came out. For me, sometimes you'd be doing something, you start to see smoke, something like that, right? And you think, "This is crazy. This is not enough."
So a couple things to know. Number one, it's always a bulb syringe, right? And you can do this case very easily with a tech, because the whole case is typically set up on the mail ahead of time. And I've got it just to the right of me like a buffet, right? So whoever's with you assisting you, they're just irrigating whenever you're running the burr and copiously, right? So Brian mentioned chilled saline. You know, if you tell your staff to put the saline in the fridge, like maybe two or three days in a row. Typically they just do it in the future when they know you have MIS cases and you just have them pull it out right before you're about to get going with the burr. It's just again trying to cool the burr to prevent heat generation so you don't see non-union, skin necrosis, etc.
The other key points are that you want to pause every kind of two to three seconds. Just let the burr cool down for a second and a lot of times you learn to like know the pitch of the burr when it's advancing and when it's not and you'll hear a slight change in pitch when it's not advancing. And that's typically because there's so much bone debris within the flutes that it can't cut. And so you're pushing harder and there's less cutting flutes generating more heat on the burr. So you want to pull it out clean it right every time you pause and I just pull it out my assistant cleans it takes literally not even a second to do.
But those are really the keys when you're trying to reduce heat generation. Because, you know, for us who do a ton of this, I'm with Brian. I think I've got two, well, one I've revised, one I had to watch for a while at the late union, but in my career, you know, similar numbers. So it really should be a rare occurrence. If you're seeing nonunion, then, you know, it should be a sign that you got to slow down, pause more, irrigate more, because it's really not something that people who are experiencing MIS see any more than 1% of the time, I'd say.
Dr. Gonzalez: Yeah. I think you both bring up excellent points. And I equate this to somewhat anterior hip replacements. When those started, people who were starting out, some of them had femur fractures and they had these issues with getting exposure and it was a technique issue, not a—it was a surgical technique issue with the surgeon, not per se, the approach. And I think with these burrs, again, they, the Shannon burrs are very different than traditional burrs, right? So you're not supposed to generate a lot of force on them. It's all a rotational moment and, and it should generate fairly low heat. So if you're generating a lot of heat and you're not using it correctly, you can burn the bone. You can burn the skin. Like, it can happen. They're not foolproof.
But so I think for the audience, if you are thinking of this, do a course. Do training. Learn how to use the burr first on solid bones, on cadavers. Get a feel for it because, and I agree, I have two non-unions, one I've had to revise, the other one just was delayed and eventually healed. And it's very, very rare. And so I think, and again, that's in all of my MIS surveys, that's just not bunions. So I think that we've combined them thousands and thousands of MIS cases and the non-unions are rare. So I think copious irrigation technique and using the burr is key so you have to practice you can't just go into it right off the gate.
And I think one thing that I've learned is especially when working with trainees and when you're starting you can burn the skin it's like anything right and so always check your skin afterwards if there's a little burn on the skin or a little epidermolysis, just excise size it out, it's such a small incision and then that minimizes your wound complications because the infection rate and the wound complication should really be below 1% in these cases. These incisions are like arthroscopic or smaller portals. So again, if you're having that problem, really look at what you're doing because that should be minimal.
Dr. Schipper: I just had to like we are hyper focused on the burr. We're talking about this technique but it's even I have my assistant irrigate the wires the drill bits I'll never forget early on in my MIS like had this lady. She had just great bone And I'm putting in this wire at that extreme angle the wire for the 4.0 headless cannulated and screw and it got hot and she got a little skin burn kind of proximal up at the ankle, right? I mean, just don't forget about that, especially adolescent patients. They've got great bone. Everything is irrigated if I'm putting on power.
Dr. Gonzalez: Yeah. I do the same because when you're doing percutaneous, things can heat up, the drill can heat up, you're touching the leg. You just don't want to get a burn. It's easy to avoid with the copious irrigation.
