A Guide to Fixation Techniques for MIS for Hallux Valgus
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Any views and opinions expressed are those of the author(s) and/or participants and do not necessarily reflect the views, policy, or position of the Foot and Ankle Surgery Institute or HMP Global, their employees, and affiliates.
Transcript
Tyler Gonzalez, MD, MBA, FAAOS: Hi, everybody. My name is Tyler Gonzalez, orthopedic foot and ankle surgeon out of University of South Carolina.
Oliver Schipper, MD: Hi, my name is Oliver Schipper. I'm an orthopedic foot and ankle surgeon at the Anderson Orthopedic Clinic in Northern Virginia. I practice just outside of D.C.
Brian Loder, DPM, CWS, FACFAS: Hi everybody, my name is Brian Loder. I am a podiatric foot and ankle surgeon. I practice in outside of Detroit and Clinton Township, Michigan.
Dr. Gonzalez: Dr. Loder, you know, I think one thing I just want the to talk about for you is kind of walk us through kind of the rationale for your fixation. Do you use one screw or two? Why or why not? and then there's various other options out there and kind of next generation implants such as intramedullary implants, things like that. What are your thoughts for the fixation of these minimally invasive bunions in terms of the screw construct and why you choose one and also these kind of evolving intramedullary implants?
Dr. Loder: Yeah, my approach is usually a 2-screw approach, which both 4.0 fully threaded, non-compressive chamfered head, headless screws. That's my approach. That has been the standard for me, but that is changing. There's been some learning curve or, like I like to call, comfort curve and getting used to using that fixation, and at the beginning some of these intermediary plates just weren't the right fix to solve that for an MIS surgeon, but now there's new fixation, intermedullary plates that are coming out that could be easily the same outcomes for individuals who can't master that percutaneous approach with the screws. So I think there's a lot of optimism about the new hardware coming out to bridge the gap between surgeons who are having trouble using the percutaneous, purely percutaneous approach.
Dr. Gonzalez: What are some of these, what's kind of these newer generation plates that you mentioned kind of do? What makes them better than older generations?
Dr. Loder: Well, they allow a 100% shift or an 80% shift that just wasn't there to begin with. They are hugging more the lateral cortex and their locking mechanism creates a greater amount of strength. Some of the older plates used to call just swap off an osseous bunion for a metallic bunion and then there was irritation at the plate site but some new on the markets coming out will satisfy this and allow the 80 to 100% correction but without using the truly percutaneous approach.
Dr. Gonzalez: All right, great. And Dr. Shipper, what you use two screws as well and why not just one?
Dr. Schipper: Sure, so I think definitely these two screws, I use the same setup as Brian, both 4.0, both headless, cannulated, non-compressive. You know, the most important screw is your proximal screw. It should be placed from the base of the first metatarsal through the lateral distal first metatarsal shaft cortex. Ideally, it exits that cortex. It runs a centimeter from the osteotomy site. It's that cortical bridge is what gives stability to the standard kind of, we say, to minimally invasive, transverse, distal first metatarsal osteotomy and osteotomy construct, that's what META is. That's the fourth generation technique. But again, it exits about a centimeter from the osteotomy site and then enters the lateral first metatarsal head. That is your stability screw. That's where the majority of the strength of this construct comes from.
And then we typically add the second screw, which is really for torsional control. I have, I can think of one patient where I saw, you know, a PT too aggressive on the patient, they basically cause a rotation of the correction. You know, it's slight, it wasn't enough, I had to go back, but nonetheless, you know, it just did give me pause, think, hey, I really, two screws, I think are important for these patients, just to protect and torsional control, and there's biomechanical literature to back that up. So, you know, again, it's two screws for me, but that proximal screw is really the most important. That's the one you want to take time on.
To Brian's point, I think there really is a lot of new exciting technology coming out. The reality is, for some surgeons, maybe especially surgeons who are later in their career, they're so set in their ways, they don't really want to rock the boat too much. Learning how to use the burr maybe is daunting or not something they really want to get into because it's kind of a different skill set. It's a different tool. But again, there are options coming where you can have the same kind of correction, large intramedullary shift, or sorry, to correct the 1–2 IMA. And again, with a jigged, it's a jigged correction to make it as easy as possible. I think that's an exciting option coming up for people who maybe are, not interested in learning how to use the burr or worried about going through that kind of learning curve using the burr.
