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2021 AOSSM-AANA Combined Annual Meeting Recordings
I Blew Out the Back Wall
I Blew Out the Back Wall
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Video Transcription
Thanks, Mike, and I'm going to address this a little bit. There's a young crowd compared to me, and so you haven't had to deal with over-the-top reconstructions or part of the over-the-top, over-the-back reconstructions or extra articular. I'm sitting down next to Rob Hunter there, who's my age, which is over 70, and he had an extra articular reconstruction back when he was a resident. Stable knee, and he's not getting his total knee until later this year, so that's pretty good durability. So anyway, I'll talk about it a little bit. My disclosure is nothing really pertains to this, because we take money from anybody to support our fellowship. They've got no influence. So to go back with 40-year history, I've been doing it for 40 years. We're doing extra articular reconstructions. The Macintosh II then switched to be extra articular and intraarticular, and then the Macintosh III, which is a QPOT, quadriceps patellar tendon over-the-top, non-anatomic. These were put over-the-top, no femoral drill hole. All you young guys can say, well, you can't do it there. Actually, you can. You can put them there, and you get stable knees out of them, and in fact, we know you can get stable knees out of them, because the Macintosh II evolved into the McKaylee-Coker pediatric open-fice seal procedure. It's essentially the same, and if you look at it, that still has among the best stability results for the open-fice's kids, so it still works well. It's just you have to be very careful to tension them in full extension. You can't tension them if they're in flexion, because you can make them too tight that they won't be able to get their extension back. So the evolution from the over-the-top moved into femoral drill holes. This is a Bill Clancy article from 1982. I learned how to do bone tendon bone grafts from Clancy. He put the drill hole very posterior, because he thought that you had to do that to get things appropriate for the position of the graft at that time. Things have obviously changed, and I know he's evolved over the last 40 years as to how he does it, but there was an increased risk of blowing out the back wall. And if you're doing this with a standard medial portal technique, if you blow out the back wall, in reality, 90 percent of the time, it's only the central portion towards the notch that you blow out the back wall, and if you go out to the lateral cortex, you still have a posterior cortex intact. The femoral drill holes, so the over-the-back guide, were good for us. The two-incision technique, which is what we were doing at that point, and it was originally a big open procedure, then two small incisions, you could routinely fix them, either on the lateral cortex, now you could do it with a flip button or anything else that you might want to do, or you can put an outside-in interference screw to fix the graft way out by the lateral cortex with a small second incision. So there's a number of ways to get around that partial blowout, which is what you're most likely to see. If we keep going through the history, Tom Rosenberg in 91 introduced the trans-tibial technique. That essentially did away with blowout on the back, because it's almost impossible to get far enough back with the trans-tibial technique to blow out the back wall. You have other problems, obviously. It's easier to put it in the wrong spot, but it's not out the back. It's too far forward or too high. So Freddie kind of redirected us back to independent femoral drilling, and not everybody in this room does it, but I suspect a lot of people do independent femoral drilling, either through a medial portal or an outside-in guide, because it does allow you to get a better anatomic fixation. So how do you avoid blowing out the back wall with this? Well, I put Mark Steiner's picture on this, because Mark taught me a lot about where things are, and we miss him sorely now. But anyway, what you do is you look through the medial portal. I drill them hyper-flexed, so flexed 120 degrees, and that is an over-the-back guide that that's going through, and it's actually 11 millimeters, so it puts you 5.5 millimeters in front of the over-the-back spot that's going to leave something in the bottom. You then swap that out. It's actually now a flexible nitinol wire, so I can bend it straight in the knee, I can look down over it, make sure I'm in a happy position, and then easily ream over it. But all of this is done with a knee flexed at 120 degrees, and so you can do that a number of other ways, outside-in, curved wires, there's just a bunch of places. But you can see, you get a nice posterior cortex without too much trouble. So what do you do? What data is there? There's almost no data, so I searched the last 40 years of literature, came up with one paper that actually compared posterior wall blowout to a non-posterior wall. The Chinese Journal of Traumatology, which I'm sure everybody in this room subscribes to and reads on a regular basis. So if you look at it, retrospective cohort study, they just match 10 for 10, hamstring autographs. They had partial blowouts, so if you look at the picture on the bottom right, partial blowout at that spot, they still had lateral cortex. So they did standard flip-button technique, because the lateral cortex was intact. If you look at them, no difference on their measured laxity or their clinical functional scores. But as I said, at this point, if you're going to do something, you've got to be careful of tensioning and extension. If you look at Bob LaPrade, he just had a great summary of what to do if you have issues. And the real thing is if you blow out the total tunnel, is you can go fix it on the lateral cortex. You can just go up there, you can put a screw up there. Even if you've got no cortex behind it, you can get good fallback fixation. Tension them in full extension, though. Don't over-constrain them by tensioning them in any flexion. So there are the references for you, and thank you very much for your attention.
Video Summary
In this video, the speaker discusses different techniques and advancements in knee reconstructions over the past 40 years. They mention various procedures such as extra articular and intraarticular reconstructions. The speaker also highlights the importance of careful tensioning and extension in these procedures to avoid complications. They reference studies that compare posterior wall blowout to non-posterior wall blowout and discuss the results. The speaker concludes by mentioning the importance of fixing blown-out tunnels on the lateral cortex and offers references for further reading. No credits were provided in the video.
Asset Caption
John Richmond, MD
Keywords
knee reconstructions
techniques
advancements
complications
posterior wall blowout
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