Our next speaker will be Dr. Al Shafai, who will present insights into the past and future of atlantoaxial stabilization techniques. Thank you very much for accepting this abstract for our presentation. I must say, when I was a resident not too long ago, this session would have been a very, very boring session for me. But listening about the history really gives you a little bit of insight of who you are and how you can go forward. This paper, this is a bunch of residents and students who keep me alive and I work with and I learn from them and they learn from me. And Minoo is a student in neuroscience and she did this project, but she unfortunately can't come here from Toronto. So I'm presenting this. I love this picture because it gives you a little bit of futuristic look from the past so that we can evaluate our history, see what mistakes have been done, and try to learn from them so that we don't repeat the same experience in the same way. So it gives you a bit of insight of how to work around them and then inspires you to do better. So what we did is we just went through a retrospective literature review with no year limits and we tried our best to be comprehensive, but I'm sure we missed some nominal and amazing people who have contributed to the C1, C2 instrumentation in spine surgery. A typical patient jumping in a shallow water and having an unstable, let's say, Jefferson fracture and you're in a situation you have to stabilize this patient. So what would they have done in 1910? The first paper that I was able to find in terms of stabilizing C1, C2 posteriorly was in 1910 by Mixter and Osgood. This is Robert Osgood from Boston and basically they used the silk threads posteriorly to stabilize the C1, C2. So that was the first publication that I was able to get hold of. Heading north to Toronto, Galley published in 1939 wiring and bone grafting of the C1, C2. In fact, when I was an intern, some of my semi-retired faculty were doing the Galley fusion. So I actually did this and it's wicked. It's really, it keeps it solid and you go through two areas. Right and left and you put the bone graft. But passing that sublaminal wire was a little bit scary for an intern. Arthur Brooks, for Brooks and Jenkins in 1978, published a modification trying to improve and make it more stable by going through both sides and that's the Brooks, Galley and Brooks. In 1991, Dickman and Sontag from the Bowel Neurologic Institute tried to improve in it and tried to look for all the areas of deficiencies. So they went with smaller wires. They tried to pass it in the center under the C2 and then that's the story of wiring and bone grafting. Looks like it has been like a table tennis ball, jumping from the United States to Canada and then back to the United States. And then people started thinking, we want to avoid passing sublaminal wires. We want to reduce the risk of neural injury. Along the way, back, the ball goes back to Canada, Ren Holmes, who actually did his training in Toronto and went and became the chairman in Halifax, tried to describe the first interlaminal clamps. So hooks and clamps, you know, people started doing these things. The idea was introduced by William Tucker, but was done by Holmes and they were co-residents in the program. The problem with this method is that it actually slips before it even fuses. So it didn't work out. So it didn't really last long and people did not do it. And as things have been happening, MRI started getting popular and people started understanding these pathologies even better. Across the Atlantic, an Austrian neurosurgeon working in Canton Spital Hospital in Switzerland, the famous Migrel, published a paper talking about C1C2 transarticular screw, which is still being done until this time and it works very well. It is really good in stopping the C1C2 translation movement. I think one of the caveats of it is sometimes there is a translation and you have to align the C1C2. But other than that, I think a lot of people believe that they should do this. I have been trained in my spine fellowship to just do C1 and C2, which we will talk about. But this is really a good way. But it becomes a little bit difficult when you have a high-riding vertebral artery. 1984, in India, Atul Gule wrote a paper talking about separate C1 and C2 screws with a plate joining them posteriorly. And as the years passed by, they were a bit modified by harms going with the rods and he publicized the technique and refined it. And then more neurosurgeons came out and they started using a little bit more different entry point, notching technique, and so on. And as you can see, it moved on from Bombay to Heidelberg, back to the United States of America. Wright from St. Louis talked about C2 translaminar screws. And they're really good. Biomechanically, not as strong, but really safe. But then what about minimally invasive spine surgery? It does have a role here. People talk about, you take C2, big spinous process, which is a really good construct, and you just take it away and you eliminate it. You take the posterior tension band and the muscles. Why not avoid doing that? And we can go through all the advantages and disadvantages of MISS and all the debates that comes with it. And I think it does have a place. And a lot of pioneers recently have said that MISS has a place in C1, C2. Posteriorly, this is the first case report by Josepher, New York. I'll show you a real case. Basically, you will need to do three incisions, one in the midline for the navigation, and then bilaterally. It depends whether you want to do a parsed screw or a pedicle screw, so where your incision will be. But it's a matter of having navigation and tube systems and going in and distracting intramuscularly, dissecting through, and then with the window drilling the area where you would put your graft, and then putting your instrumentation and your implant. So it is doable. It can be done. And it is getting more popular. There are a lot of people that are talking about doing these MISS techniques posteriorly. But we never talked about the other side of the coin, anteriorly. So six years later, a description of invasive anterior transarticular screw came out from a Chinese author. So there is a place for this in an MISS technique. He goes through the same techniques that we always do. You know, you bring the fluoro, you have an entry point, you do your scopes, you put your screws, you drill your graft. But why is it not as popular? The reason is the approach is scary, and the complication rate is higher. We need to understand this approach better. And maybe this kind of approach has been handled by general surgeons, head and neck surgeons more than neurosurgeons, so we're not as familiar. And the complication rate is higher. This is the first paper published in 1966 in UCSF San Francisco for a patient with chordoma having an anterior lateral high cervical retropharyngeal approach. Tumor was completely resected. The patient died. But there has been papers coming on and off talking about this approach. It goes up and then comes down. This is quickly a paper from a Canadian group from Montreal. And well, Dr. Ivey, Max Ivey, moved to Switzerland. But basically, there are trajectories and alignments, and it can be done very well. So anterior approaches can be done openly, and there has been some techniques going on and off, and some people trying to do them in the 70s, came back in 2000, early 2000. But it's still, there's lots of questions about the safety of the method. So what's the future? Robotics and microrobotics, dexterity enhancements. The future would be using virtual reality and neuro-navigation. I think there is a lot of work that can be done in this area. And there is no question that this history can teach us not repeating our mistakes. But I think we should repeat some of the techniques that have failed because now we have new technology. And they might work with the new technology. So I think C1, C2 is exciting for the future. I think there is a lot to do with this area. Thank you very much.

atlantoaxial stabilization techniques

historical overview

silk thread stabilization

wiring and bone grafting

C1C2 transarticular screws