In trauma surgery, as a rule when you are negotiating with someone, you need to take into account how invested they are in the long term functioning of the system. If that person could get a dozen jobs in the city by next week, they are likely not seeing things the same way.

RT @TSACO_AAST: In India, 19 people die every hour from road traffic accidents, and 35% of traffic accidents are fatal. But in some areas,….

The merits of 2-handed (versus 1-handed) knots are also controversial. People have strong preferences. As for me, most (> 75%) of my knots are tied 2-handed. I have also done 🧵on both 1-handed knots and instrument tying. we will look at these again later this month. ⬛️

One thing that *constantly* happens is that before you can finish your 2nd throw, the 1st throw has become loose. If you tie this, you'll get an air knot. There are various techniques to deal with this: surgeon's knots, slip knots, etc. These are covered in other 🧵.

Here you can see that in order to get the strings uncrossed, I have to cross my hands. The knot will now come down as a true 'square' knot. Surgeons vary in their opinions about whether or not it is important to 'square' each and every one of the throws in a knot.

What makes the 2nd throw different is that the threads are now *crossed*. You can't simply tie these down right now, unless you're willing to accept that it won't be a square knot. In order to uncross the strings and make it a square knot, you will have to cross *your hands*.

Here's a video of the 2nd throw. Once again:. -make the 'X'/loop.- pinch.- move pinched fingers through the loop.- grab the string.- go back through the loop. Though the steps are the same, there *is* one major difference at the end. We'll see this next.

We'll move more quickly now because the remaining steps of the 2nd throw are basically the same as for the 1st throw:. -make X/loop.- pinch.- move pinched fingers through the loop.- grab the string.- go back through the loop.Note that I had to briefly let go of the string again.

The process for making the 2nd X/loop was probably not obvious on the last slide, so here it is in video form. You can see that after setting the 1st throw down, I am now lifting up the R string with the back of my thumb. I can now make the 'X'.

Now we begin the 2nd throw. It will be very similar to the 1st. in fact the steps are basically the same. The difference is that when you make the 'X'/loop, you will instead be using your *thumb* to lift up the string (remember in the 1st throw, you used your index finger).

Here's the 1st throw, all at once. We have taken a long time to get here. But the 2nd throw will be very similar. In both cases you will:. - lift up the R string.- make the 'X' and loop.- pinch fingers.- go through the loop.- grab the string.- bring it back through the loop

Now we are finishing the first throw. Sometimes you can just pull on the strings (L picture). However, sometimes it's better to push on one of the strings to 'set down' the throw. If tying deep in a cavity, you are usually forced to do this. More on this in another 🧵.

Here's a short video of going back through the loop. Again, note that I had to let go of the string with my left hand. I then picked it back up again afterward. Now that I've done this, the first 'throw' is basically complete, and all I have to do is 'set' it down.

Now that I've grabbed this string with my pinched fingers, I'll bring the string back through the loop in the opposite direction (L photo). You'll find that in order to get the string to pass through the loop, you'll have to briefly let go of it with your L hand.

Now that I've grabbed this string with my pinched fingers, I'll bring the string back through the loop in the opposite direction.

The next thing is to pick up the string that's in my L hand (the one I've been marking with a yellow line). You will have to briefly open up your pinched fingers a little bit to be able to grab the string.

Keeping my fingers pinched together, I will then move them *through* the loop (orange arrow). My pinched fingers are now on the *opposite side* of the loop (R picture).

Now that we have made the 'X', and by doing so, also made the 'loop', the first step is to simply pinch your finger and thumb together.

By making this X with the strings, we have created:. - a 'loop' (red dashed line). - a segment of string outside the loop (yellow line). Most of the activity in tying a 2-handed knot has to do with manipulating these two things.

Shown here is a short video of *just these first steps*. We now have created both the 'X' and the 'loop'. We will need to use the 'loop' concept over and over again as we tie the knot, so it's important to understand it. ( See the diagram on the next tweet).