When Is MIS Indicated for Bunions?
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Transcript
Tyler Gonzalez, MD, MBA, FAAOS: You know, Dr. Schipper, who are you doing these MIS bunions on, what are your indications? Who do you choose it on? Who do you not choose it on? How do you make those decisions?
Oliver Schipper, MD: So for me, I mean, again, I teach this across country, I've been doing this for so long. It really, for me, mild to severe, hallux valgus, I'm gonna do it. Patients, as Brian said, they come to us for this procedure 'cause they know we do a lot of it, we've got that reputation. And I just feel like it's, in my hands, the most reliable correction for my patients. So, I mean, for me, it's pretty much everyone who walks in the door with a hallux valgus deformity unless they have a rigid deformity. I often don't do this in them.
If they've got, I always ask patients, it's very easy when someone comes in with a hallux valgus deformity, and they say big toe pain, you assume it's from the big toe, but you always want to ask the patients about their type of pain. Typically, hallux valgus bunion pain is rubbing in shoes, right? If they're in sandals, they tend not to have pain. When they tell you they've got pain deep in the joint, in and out of shoes, usually you want to be thinking of do they have some kind of early hallux rigidus, do they have some kind of sesamoid pathology going on, just want to be careful you don't fall into the obvious. But again, for me, 100% of the time I'm doing this technique and just because again, I feel like it's so reproducible in my in my hands and my patients are happy.
I did a “What's New” in AOFS in 2023 and I mean the amount of literature supporting these techniques is pretty immense. Certainly the third generation technique and even the fourth generation and really from everything from mild to severe, we typically quote our current rate of about 7.5% and in severe bunions, certainly a little bit higher. The downside with severe bunions is there's a higher rate of residual deformity, which can be as high as 25%, but again, patients are typically happy. It's such a vast improvement compared to where they were living. You know, again, in my patient population, they've been really happy whether it's mild or severe.
Outcomes of Third- and Fourth-Generation MIS for Bunions
Dr. Gonzalez: And Dr. Loder, you recently published your outcomes on third- and fourth-generation MIS bunions. In that study, what did you find of your indications for bunions? Did you have the same experience of good outcomes in the mild to moderate to severe bunion correction for MIS? Do you do something different or you have similar indications? And what did your study show us?
Brian Loder, DPM, CWS, FACFAS: First of all, the study showed that if you're doing an 80% to 100% shift, regardless of the osteotomy type, chevron versus transverse, the correction was equal. The reason why I published that article is because a lot of individuals were claiming to me that the chevron didn't allow enough rotational shift, and that's why you needed the transverse. But once you're 80% or more, you can rotate that modified chevron, no problem.
As far as my indications, it's just like Oliver said. The indications are such that mild to moderate to severe house valgus deformity is in my wheelhouse for these, as long as there's no degenerative joint changes or stiffness. I think stiffness is your biggest thing. If you can't reduce this at all, there's gonna be too much tension on your hardware, on your osteotomy. Even getting the shift is very difficult with instrumentation, and then when you get it, it's hard to keep it there in the weight-bearing position. So I always try to, when I train individuals on the percutaneous, the first couple they do, pick an easily reducible deformity, moderate, not mild, 'cause the shift is hard and a mild to get those screws in, but pick a moderate deformity that's reducible on the clinic table that you can close it down easily so that you know you're going to have a really good outcome with this patient. Stay away from the really stiff, large, older deformities that you can't reduce because they're hard to get over and when you do get them over, they're hard to keep them there because they're so rigid.
Dr. Gonzalez: Yeah. And I think for me, it's the same thing. My indications are the same. I think the difference in traditional—so sure, if there's arthritis in the MTP joint if they're stiff, non-reducible, no bunion in the sense of an open chevron or an MIS is going to work because they're rigid and they need a fusion. However, where I think for a distal chevron or distal osteotomy, severe bunions, you couldn't get the shift open, but now with this minimally invasive technique, we're able to get such a correction of the IM angle that we can do severe bunions with good correction and I think that's where the real difference is the indications have expanded for a distal osteotomy with minimally invasive surgery, which didn't exist with open. So I think that's kind of expanded our breadth of the patients we can treat and as Dr. Shipper alluded to, some of our elderly population are patients with these awful deformities that traditionally may need a Lapidus procedure or MTP fusion I think we can give them an MIS bunion correction, obtain good correction. There might be a slightly chance of recurrence, but these patients tend to be walking immediately. They're often low demand and they're extremely happy with their outcome and a fast recovery, which I think is a big game changer.
Dr. Loder: Oliver said a good point, and that is that individuals, even if they have a large deformity and you don't get 100% correction, they're happy. Well, that's because it's on the spectrum of it didn't—wasn't hard to get there. If they underwent an osteotomy that took 6 to 9 months to heal and they couldn't get back and choose and they didn't get the result, they'd be far more upset about the outcome. But since the outcomes are so quick and easy to get to, if even if you don't get 100% result the patient is still satisfied because they weren't put out that far for it and I think that's an important point to understand.
Pointers on Hallux Valgus Revision
Dr. Schipper: Well, I mean it's great for revising a Lapidus the first TMT joint’s already fused this really is a great technique for that and then you know I think we didn't really talk about it much but just I've seen enough Lapidus. You know, again, I'm in a very affluent area where they recur like through medial intercuneiform instability. And you know, again, I feel like we're just taking a lot of slack out of the system with this technique where, you know, I don't have to watch a Lapidus recur, you know, as I might have before.
Dr. Gonzalez: Dr. Schipper, do you do this on not just revision, like Lapidus, but other, like if they have a recurrence of their distal chevron or another type of bunion, can you use this technique to revise the bunion?
Dr. Schipper: I mean, definitely. If there's a large 1 or 1–2 IMA, I mean, it's really a great technique. For any sort of revision, I just the only thing to know, if you go right through the prior osteotomy site, sometimes it's a little more sclerotic, so you gotta go a little slower with the burr 'cause you may generate more heat. That's just one technique tip for that. And there was one other, metadductus, that's the other big one. You know, they've got a large hallux valgus angle and a small 1–2 IMA, you know, just like with a Lapidus procedure, right? Ideally, you wanna correct that metadductus and we may do osteotomies down at the level of the first TMT joint, the second and third metatarsal bases. But if you leave that uncorrected, that severe, again, I don't do it on mild metadductus. I do it on severe. And typically, like I said, in that case, high hallux valgus angle, small 1–2 IMA. If you don't correct the metadductus in that situation, they will high chance of recurrence. And I tell those people too, I mean, I tell anyone flat feet or metadductus. I mean the literature says they definitely have a higher risk of recurrence in hallux valgus. It doesn't matter the technique.
