Okay. Yeah, it's on. Okay. So we'll move down the forearm, to the forearm now and talk about the exposures for radial and ulnar shaft fractures as well as the distal radius and distal ulna fractures. The soft tissue envelope for the ulna allows easy access basically along the entire length at the ulnar subcutaneous border of the ulna. The radius has a more complicated envelope with multiple layers and multiple things in the way in the layers or in between the layers. So it's a little more complicated getting to the radius. We'll start with talking about the radius and there's two basic ways to get to it either from volarly or from dorsally. The volar approach with the eponym of the Henry's approach is on the anterior or volar aspect obviously. It's used for fractures. You have access to the entire radius through this approach, but typically, more commonly, it's used for fractures of the distal two-thirds. The landmarks for the skin incision are the radial styloid distally or maybe just a little bit ulnar to that and approximately just lateral to the biceps tendon. The interval that you're using on the superficial dissection is the ulnar border of the mobile wad or the brachialis here, which actually does extend fairly centrally across the anterior forearm. The interval approximately is this brachioradialis and the pronator teres. And as you move distally, it's the brachioradialis and the FCR. You can see on this sort of model the radial artery is right there and the radial artery is actually right in this interval for the entire length. And so obviously, that'll be at risk. As you go deeper, the interval, there's a couple different ways to get in there, but the classic approach distally is along the radial border of the radius, taking the radial artery ulnarly. And so the interval there as far as muscles are the brachioradialis and then the pronator quadratus, FPL, and the radial artery, as I said. At danger during this distal part is the radial artery, obviously, and there will be branches of that that have to be ligated or cauterized. And the superficial branch of the radial nerve, which is underneath the mobile wad, the brachioradialis. As you move approximately, you'll come across the tendon for the pronator teres, which isn't shown here, and then the supinator. And the exposure will be elevating the supinator from its more ulnar border and elevating it radially. The biggest risk during this exposure and any exposure really to the proximal part of the radius is the posterior interosseous nerve, and that's because it's hidden. It's enveloped within the supinator between two layers of the supinator, and so that's sort of the key to being safe to this exposure is watching that. Also, as you get really proximal here, the lateral anabrachial cutaneous nerve is in the more subcutaneous tissues, and we'll see that on the dissection. There's variation to this exposure, more typically used for distal radius fractures, the FCR And in the FCR approach, instead of taking the radial artery ulnarly, the interval, or you take the radial artery radially, so the interval is actually right along the FCR tendon. It's used, as I said, for the more distal fractures, distal radius fractures, because it's easier to mobilize the radial artery radial and get good exposure of the entire radius. Because it's a different interval, there's a little bit different dangers. You are more ulnar, and so the median nerve comes into play, and particularly the palmar cutaneous branch of the median nerve. That branch is quite small, up to a couple of millimeters in size. It branches off of the median nerve about three or four centimeters proximal to the wrist crease, and then runs right along the FCR sheath, and sometimes can cross the sheath to supply the skin. Transsection of that nerve doesn't cause big functional deficits, as it's just sensory, but it can cause a neuroma, and people do complain about anesthesia in that area. So the exposure for this part of the approach is right through the FCR tendon sheath. You go through the superficial sheath. The radial artery is usually pretty easy to see, and then if you stay more towards the radial side, the palmar cutaneous branch is safer. It's more difficult to see, which makes it more dangerous, but staying on the radial side keeps you further away from that, and allows access to the PQ and then the distal radius. Switching to the dorsal approach to the radius, this again allows access to the entire length of the radius from the wrist to the elbow. Most typically it is used for the proximal half or proximal third, I would say. The landmarks for the skin incision here are Lister's tubercle, and then the radial head or the lateral epicondyle. The interval for dissection superficially is the ECRB, which Dr. Mounier was talking about earlier for access to the lateral elbow joint. The ECRB and then the EDC, which are shown both retracted on this, they are touching in the predissected state. Distally, the interval is between, again, the ECRB tendon, but the EPL after it crosses over towards the radial side of the wrist. Sort of complicating this exposure, you may say, are the outcropper muscles, the APL and the EPB, which go obliquely in between EDC and ECRB. However, in a lot of ways, these sort of simplify the exposure. Really, the easiest place to find the interval between ECRB and EDC is where these muscles come across. It's pretty obvious. It's right in the middle of the forearm, and so you're usually here plating fractures, so you need exposure for a plate. So, almost any exposure, you need to sort of get to this area anyways. For both of these exposures, you don't need to use the whole exposure, obviously. You just go center it over where the fracture is and use the part that's necessary. As you extend your incision proximally from this area, the fascia and aponeurosis between the ECRB and EDC become confluent, but it is definitely possible to sort of find the septum there and follow it proximally with careful dissection. The deep dissection is between, again, the ECRB and the distal dissection. The deep dissection, the key is, again, this posterior interosseous nerve, which is shown here exiting supinator. Again, from this exposure, it's within the supinator. It's not readily apparent and visible, and it's the most at-risk structure. Also, if you get into the wrong interval or with a lot of retraction of the mobile wad, you can cause traction injury or injury to the superficial branch of the radial nerve, which is underlying these tendons up here and muscle bellies up here. If you extend this dorsal exposure distally, you have good exposure of the interarticular part of the wrist joint. This part of the exposure can be used for distal radius fractures that are interarticular. You want to get an articular reduction as well as basically any wrist procedure, proximal rocarpectomy, wrist fusions, partial fusions, ligament reconstruction. It's a very utile approach. The landmarks for this are basically the midline of the dorsal wrist. The skin is quite mobile in this area, so it's not extremely crucial exactly where your skin incision is, but it usually makes it just ulnar to lister's tubercle. The most common interval for distal radius fractures dorsally would be, for me at least, is between the EDC and EPL. Depending on what you're doing here, you can enter basically between any of the dorsal wrist compartments. Typically what I do is enter the third dorsal compartment, retract EPL radially, and then dissect beneath the fourth compartment, keeping those tendons together as far radially as ulnar as you need to go. You can go all the way around to the radial styloid and all the way around to the ulnar side of the ulna. The big nerves, and there's no real motor nerves in your dissection here, the big nerves to the skin, the main branches are very far away also, but you will cross branches of the SBRN and dorsal branches of the ulnar nerve, but if you stay in the midline, there'll be minimal dissection of those. Also, these branches are up within the fatty layer, so if you make your skin incision, get right down to retinaculum, and then elevate skin flaps both ways, these nerves are not really too much at risk. Also of note, the terminal part of the posterior interosseous nerve lies within the floor of the fourth dorsal compartment, and it's easy to see. It provides branches to the wrist capsule, and depending on what you're there for, you may want to preserve it, or you may, in a lot of cases, want to just do an erectomy to maybe give some partial pain relief if you're working there for arthritis or some other reason. We'll also show the approach to the radial styloid. This is commonly used for fractures primarily involving the radial styloid or complicated fractures where you want fixation of a fragment over there. It also can be used for first dorsal compartment release and other risk procedures like scapulonate repair or reconstruction. The landmark is the very palpable radial styloid and the tendons of the first dorsal compartment, which are aligned directly over it. The interval for your dissection is just dorsal to the first dorsal compartment between the EPB and the ECRL. Distally over the snuff box, you have EPB and EPL after it crosses the second compartment. In this small area, a lot of times you don't need much exposure here to get wires or a single screw in, but there's a lot of stuff in this area. The large branch of the superficial branch of the radial nerve has been studied in this area, and it pretty much always lies within five millimeters of the first dorsal compartment here, and so that's right where you're working. And it often branches in that area. Also, the radial artery obviously lies just volar to the radial styloid and then bends abruptly beneath the first dorsal compartment tendons at the tip of the styloid going dorsally to the sort of the first web space here. So those are all at risk with any sharp dissection in that area. And finally, as I said before, the approach to the ulna is much simpler. The ulna has a subcutaneous border for the entire length from the olecranon to the ulnar head. And really, the ulnar artery and nerve are the closest structures along the length, but there's a good soft tissue envelope between those and the shaft. The ulnar nerve does get opposed right to the bone at the elbow as was already dissected, and so if you're working on a comminuted fracture in that area, it is important to identify the nerve and protect it. And then also right at the other end, the dorsal branches of the ulnar nerve, again, lie right over the ulnar head. So if you're working on a fracture there or TFCC procedures, the dorsal branch splits off from the main trunk about six or seven millimeters proximal to the ulnar styloid, and then two or three centimeters from that, it pierces the fascia and becomes subcutaneous and runs right over the ulnar head. Okay. Any questions about sort of just the diagrams? All right. One, two, three. No. Okay. Mic working? Yeah. Okay. Okay. So, I guess we'll start with the dorsal approach. For the landmarks, again, it's basically the radial head or lateral epicondyle, which are palpable approximately. And then, Lister's tubercle, dysle, which is pretty much always palpable. And again, you only need to use the portion that you need for exposure for just reduction and then plate placement. For skin incision, you try to identify that interval between EDC and ECRB. So we dissected this yesterday, but as you can see, approximately, it can be a little bit hard to find. The muscle fibers just kind of run into each other, and there's this sort of striped candy appearance of the fascia overlying it. However, dysle, these muscle tendinous units become more tendinous, but also you can see these outcropper muscles, APL line right here, and that splits the interval right between those. So this is sort of what it looks like, and that's pretty easy to define. Like I said, that's very central within the forearm, and so you almost always need to be there anyway. So that's generally where I would find this interval. Dysle, you just follow the EDC, which becomes more easy to define as you follow it dysle. You can split this fascia between ECRB and the APL, and then just with an elevator, get underneath these outcroppers, and that will allow access to this distal portion of the shaft. And so you can put retractors around this, and you can actually just do a little more along this border here, and get that entire portion of the shaft there, and then if you're working more proximal, you can retract these a long ways distal too, and have this access. As you move proximally, again the muscle fibers come together, and it's a little bit harder to see your interval, but if you start distal and move proximal, you can just sort of follow this fibrous interval between, and come as far proximal as you need to, all the way to the elbow joint. Coming from distal to proximal, we got the arm in pronation here. Here is the insertion of the pronator teres, you see this is not very prominent and well opposed to bone. We supinate, you get more muscle fibers there, and if you're plating in this area, a lot of times you can just leave that insertion alone and place the plate right over the top of it. Now the key part of this exposure is for the proximal area, which is where you're most commonly using it. And the supinator muscles, pronator teres are oblique coming from proximal radial to distal ulnar, the supinator is basically 90 degrees from that, so you can see these fibers or fascial fibers here going proximal ulnar to distal radial. And once you get to the supinator, then that's where you really need to start being careful. So here's the supinator, the at-risk structure really for this is the posterior interosseous nerve. And depending on how proximal and distal you need to go, there's a couple different ways to find the posterior interosseous nerve. Let's pronate it. The most straightforward, well, the easiest way to get to it actually is at this distal part. It doesn't actually leave the supinator directly from the most distal part of the supinator, it comes out from beneath the superficial part of the supinator, they'll say a centimeter or a centimeter and a half proximal to the distal edge. And so here is the posterior interosseous nerve lying right here. And as you can see, it's actually fairly good caliber right as it comes out, but it arborizes extensively directly after. And also in the predissected state, there's a lot more fat in here, so you really kind of have to take your time. All of these fibers are motor fibers, and so it's worthwhile to save all of those if you can. And so you really got to kind of take your time dissecting through this if you're interested in actually seeing it. You do need to see this nerve if you're going to be working anywhere near this. Now if you have a more proximal fracture and you need to get your plate closer to the elbow joint, it's also often worthwhile to try to find the nerve up here proximal before you do any dissection. And so, let's see if we can get in here, on there, there's just some more fascial bands. And here, this is all supinator still. If we supinate the arm, that brings, as Dr. Mounier was talking about, it brings, for this exposure, it brings the nerve more proximal and also just more superficial to where we're working. And here is the PIN coming here into the arcate of Rosa. So I don't know if you can see that there, coming right in here. Now to be absolutely safe, people will recommend following this nerve and dissecting it just right on top of it all the way down to where it exits. If you don't need to get very proximal, and you can identify it here, a lot of times for your exposure and plate placement, you're going to elevate, the safest place, well the only place really to elevate the supinator is off this insertion at the more anterior or radial position. So you incise, I'm going to leave it for now, but you incise along here and elevate as far as you need to go. If you need to get all the way to the neck, it probably is worthwhile to dissect that PIN out, depending on how confident you are. Pronate again. People also describe that you can sort of feel it like this. I've never been very confident with that. It's not that big of a nerve, and sometimes I think I can feel it, but if I'm worried about it there, I'd rather just see it. Extend this a little bit, and supinate again. At this most proximal extent of the exposure, also, at risk is, or let's see if we can see, here is the superficial branch of the radial nerve. So you see, as you're doing your exposure, you're able to retract that quite a ways, and it's not nearly as risk as where you're putting your plate here, but over-retraction can cause injury to the superficial branch of the radial nerve, and as the more proximal you get, it comes to the branch point, and here's your superficial branch here, and you can see it's close to where you're working there. Also, more superficial within this same interval, you'll often see the lateral anterbrachial cutaneous nerve. If you're coming directly into this interval, and the first nerve, there it is right there, you see this is coming superficial to the muscle here, and that's easy to get fooled that that's your superficial branch. It's not, but it's still important, and you should recognize that and protect that. Okay, before I take anything of that down, I think we'll go back to the anterior side. Any questions? Okay. So, anterior approach, the landmarks here are basically the radial styloid, or just owner to that on the boulder surface, and the lateral aspect of the biceps tendon. Distally, this is very close, but not exactly on the FCR tendon, and if you want to do a FCR approach down there, that's a good landmark as well. As I said before, this approach I would typically, more typically, use for distal two-thirds, just because it gets to be in a pretty deep hole approximately, but you can use it for the whole shaft. The interval here is between brachioradialis, which is here, and the FCR, basically along the entire length. Also along the entire length is the radial artery. In the pre-dissected state here approximately, it was just covered by the edge of the brachioradialis, and often it's just covered by it also here distally, but usually you get a little glimpse of it down here. The interval here is, again, the most easy probably to find between the further distal you get, just because you start to see more tendon. But even proximal, you can usually sort of determine the edge of this mobile wad either by just looking at it after your skin incision or even by palpation, the brachioradialis moves quite a bit and the EDC does not move too much. Okay, so let's cut this. So, after that incision of that fascia, you retract the brachioradialis radially, and here is your radial artery all the way along basically right in the middle. Now, I've taken this ulnarly, which is sort of the classic Henry approach. This is, it's good to take it ulnarly if you're working here more in the central or proximal portion, because as Dr. Mounier stated, the radial artery obviously comes from the ulnar side of the biceps tendon, and you'll need to get that retracted that way for your exposure proximally. Distally, the radial artery again goes around the radial side of the wrist and up into the first web, and so if you want full exposure here, it's a lot easier to retract that radially, and so that's when you'd use that FCR approach. Now, as you get deep to this, you size this, take this, there'll be branches of the radial artery that are feeding the brachioradialis up here that'll need to be cauterized. If you take it with the brachioradialis, there'll be some branches coming here more distally that need to be cauterized. From this side, starting from distal, you'll have the pronator quadratus, which we've left intact here. We typically elevate the brachioradialis and mobile WAD tendons off just from the radial border. You have pronator quadratus, and then you'll have FPL, and then through here, and then pronator teres. So this is pronator teres with these fibers, again, going from proximal ulnar to, in this case, proximal ulnar to distal radial. And then in the supinated state, such as we're at here, you'll come to this ridge at the proximal part of the pronator teres, which is basically bare. So perpendicular to the fibers of the pronator teres, you'll start to see the supinator. If we pronate this, you see much more of the muscle belly of the supinator. And as we talked about before, the supinator is what's hiding our at-risk structures. From this anterior approach, you don't really see the distal portion of the PIN because it's dorsal. You actually have a better exposure of the insertion of the supinator. So also, as you move proximal towards the elbow, this gets to be a deeper and deeper hole, and the other structures, such as the radial artery, those branches of vessels, the leash of Henry, also become more problematic. Also, just the shape of the bone is not as flat, so it's a little bit more difficult to get plates on here. And so I'd say it's rare that I actually go and try to find the posterior interosseous nerve entering into the supinator from the volar side. But if we pronate, you can see it here. If you are coming from this side and find yourself having to get up to the neck or head of the radius, there's a pronator, or the PIN, entering arcate of frost there. With supination, you don't really see that. But for exposure, if you incise right here along this basically bare ridge, you'll have access to the bone for plating. Now, the exposure along this side, as you see, you're looking much more at the muscle belly of the pronator teres. And so for plate placement, you will have to incise that. And typically, the supinator will be incised here along the ulnar-most margin and then elevated carefully radially, whereas the pronator teres, FPL, and PQ will be incised along the radial margin and elevated ulnarly. We'll do this down here. We'll talk about the distal radius a little bit from this side before we switch anything. So, as I said, at the distal radius, I'd say more commonly is used the FCR approach, which the main difference between that is you're entering the FCR sheath here and retracting the radial artery radially, where it has more plate. As you're more ulnar with your exposure, the median nerve comes into a little bit more danger here. So, let's go with this for now. This typically lies underneath the index and middle finger FDS tendons and actually becomes superficial to them as you get closer to the wrist. So, with incision of the FCR tendon sheath and then retraction, often we'll see the median nerve like this. I've dissected it out more than typical. Also, I don't know if this will show well, but that homer cutaneous branch, as I stated, exits the nerve. You can look for that approximately three or four centimeters proximal to the wrist crease. And we found a branch here, which in the pre-dissected state was laying basically on the very edge of this FCR tendon sheath coming across. And we can find it all the way out here. And it goes into its own tunnel separate from the carpal tunnel at the wrist crease and it supplies the skin there. So, that's definitely at risk with this exposure, both from proximity and also because of just how small it is. So, we incise this sheath more towards the radial side, identify the artery, which we have not separated from it here, but you can. like that. You can enter this sheath and take it this way, and then that retracts quite a ways away. Deep to that here we see a FPL tendon, and deep to that the pronator quadratus, which you would elevate off sort of this radial insertion. Take it all the way out to the styloid and around the styloid to get your exposure there with elevation of this all this way. Okay, let's go. Any questions about that? Go back and elevate this supinator off from the dorsal approach just because there's more to see from that side. So once you identify your PIN here and you decide you need full exposure of this, as I stated you see it here, and as I also stated there's a lot of fibers already going into EDC and the other extensor muscles, so traction here definitely can cause injury to that nerve. Once you identify it there and then supinate, you can see the proximal PIN entering there, and then your exposure here will be along this more anterior border, and if you see the PIN you can be confident coming very proximal. Elevate this. Now the PIN will come down and touch bone in about 25% of people, so you have to be careful with the elevation. You can't just incise and feel like you have it all the way up. You have to make sure you're right on bone with elevating this. That basically will allow your exposure all the way from the neck down to the wrist. up there, and PIN is within the supinator there. Okay, Pedro, did you have dissection for the ulnar, for the radial silent? Actually we can do the ulnar dissection real fast. So ulnar dissection is much less complicated. You have this ulnar border, especially a nice thin arm like this. You're basically through skin and right on to periosteum for the majority of the exposure. Approximately there may be some muscle fibers that are crossing the ECU and FCU fibers sort of come into a septum up there that requires that you divide a few muscle fibers to get to bone. But other than that, you have incision and right down to bone. You can do that all the way from the olecranon. So you see I've just done skin and basically there's nothing there besides bone. The most proximal portion, if you're working on a comminuted fracture, especially around the olecranon, the ulnar nerve will be sort of in the working area. And so it's worthwhile to find that. Once you get just a couple centimeters distal, it gets into the FCU and starts to leave the bone. And so it becomes much less at risk. But from this dorsal exposure here, you can find it. And if your plate's just going to be distal and you don't need to do any kind of reduction on this ulnar side, you can find it just by palpation and leave it there. But if you want to get a reduction perfect over there, it's worthwhile to split this fascia and see it. And there we have a little view. Here's ulnar nerve. I don't know if you can see that yellow band. Right there. So it is opposed to bone at the elbow joint, but then it's already going into the FCU and there's much more of a sheath, even just a couple centimeters distal. Now at the wrist, actually the nerve branches are more at risk. Stated there are nerve branches that come off about six or seven centimeters proximal to the ulnar styloid from the ulnar nerve. See if we can find anything. You can see one right there. I've got one right here, right in there, a sharper, here we go. Yeah, there's a branch right there. I don't know if this shows up very well, but there's a branch coming from Bowler near the nerve there, right up over the owner head, which there almost, pretty much always is, right across superficial. The main trunk of the ulnar nerve is actually a ways away, and so subperiosteal dissection keeps that pretty safe. Way over here, right in there, right there. Okay, so that's pretty straightforward. Yeah, so on the distal ulna you have choices, and I'd say typically if I'm doing a distal ulnar fracture, I like to get coverage of the plate because it's very prominent here, there's not much soft tissue coverage. So I will typically go bowler, and I say that you can just do a dissection here, elevate subperiosteally. Again, the sort of part of the dissection you have to be careful with is out here as you get distal, and place the plate here, just because I have more coverage typically. If there's a styloid fragment that I really want to get purchased on, sometimes you really sort of have to put that more ulnarly, which is very accessible also, but I think those plates are a little bit more more prominent. Then your ulnar artery can be at risk, yeah, and so for that reason, those plates are also more prominent typically, and also you're not seeing the ulnar artery or protecting it. If you're working vulnerally and drilling dorsally, that's something else that you've got the artery out of the way, and it's not really at risk so much. Okay, I guess should I get your arm out? Okay, there's a... Finally, the radial styloid. For exposure here, as I stated for, which you do for fractures involving the styloid, or for example, a screw between the screw or K-wires between the lunate and scaphoid, you typically don't need a big exposure, but there's a lot of stuff in this area that's good enough. So here my finger or my pointer is on the tip of the radial styloid, which is very palpable and easy to define. The first dorsal compartment tendons are here, you know, the tip of the styloid is there, and there's the tendons right directly over the tip. As stated, there is basically always a fairly good-sized branch of the superficial branch of the radial nerve that lies directly over that first dorsal compartment right at the tip of the styloid. So if you're putting a K-wire in the styloid or a plate, I would say it's always recommended to make a small incision and spread. Now you may not have to actually look for this nerve, but if you can spread and get down to bone or the tendon sheath and be sure that there's nothing in the way, then you can have your access. Now if you're putting a plate along the radial styloid, then obviously you need a little bit bigger exposure. And for that, typically, we'll do our exposure just dorsal to the first dorsal compartment, so sort of here. Here's another branch. As you can see, this has multiple branches, and if you dissect those out, they can be retracted bolarly or dorsally, just depending on where exactly they lie and what you're doing there. Enter this first dorsal compartment dorsally. Those tendons can be retracted, and you have access to bone or plate placement. The radial artery is here. Just bolar to your radial styloid. There you are, right there. So here's the tip of the styloid right beneath the first dorsal compartment, and here is the radial artery directly opposed to it and traveling beneath the compartment. And here, I don't know if you can see that very well, right here. So when you work in the snuff box, such as for pin placement across the scapulae, joint, or screw placement there, that's definitely at risk. And as I said, a small incision is what I would do to get there. Okay. Okay. Questions? Yes, sir. For a site for a fragment-specific fixation, such as Madoff's technique, when you're trying to put on a radial styloid plate, you're going to be exposing your first dorsal compartment for the most part. From your experience, have you had to basically dissect that off the bone, basically sub-periosteally elevate that to get your plate on, you know, fairly securely? I struggle sometimes trying to get my proximal screws in. Yeah. So, yeah, typically I do. I think I used to struggle more, and you can sort of put that at an angle following, but I'm typically not satisfied with that, and so I'll elevate the first dorsal compartment. I haven't done it often enough to speak from experience, but are you having trouble with people post operatively with those since you're elevating your first compartment off the bone, you know, where it could possibly sublux? Yeah, I haven't really noted that, no. I use the fragment-specific, such as you're talking about, more typically for more difficult fractures, and so I would say those patients don't do as well as a simple fracture in general, but I haven't really had that complaint that I can remember. Do you ever feel the urge to release the compartment? Yeah. Okay. Yeah, I don't really hesitate on that too much. Can you show us in your proximal dissection some, at least on the listserv, there have been some cases reported of PIN entrapment with endobutton repair of a biceps tendon? So, let's see if we can... Ours is probably good. I'm more used to where everything is. So, we can identify here, where you dissect out a little bit more to our biceps insertion. So, here's biceps coming down, supinate, to the tuberosity. So, for the dissection, just to get to the tuberosity, yeah, it's hard to hold that a little bit. The PIN is a ways away from that, and so that's not really where it's at risk. The at-risk is when you come from this side and you're drilling through through the tuberosity to the other side. So, now pronate. PIN, you can see the distal part of that, supinator, is here. So, biceps is here, PIN. So, it's really at risk on the opposite side where the endobutton fits. So, here's PIN. You can see that I've got it here in my forceps coming like this. The at-risk is basically from the drill and then the placement of the button. This is all blind when you're using a one-incision endobutton technique. You're not seeing any of this over here. So, with the arm, it's in a supinated position so that you have access to this. PIN comes across the anterior compartment and then goes to the posterior compartment, and then as it goes around, as it goes distal, it'll come more central and back sort of towards the center area. If you do your drill hole proximal and keep it ulnar, that minimizes the proximity to the PIN, and if you aim too distal, you also get closer to the branches. So, it's at risk. I forget the number on how close it's been looked at in anatomy how close it is typically from that, but keeping ulnar and not going too distal would be the thing that would keep you further away from the PIN. Okay.

forearm

wrist

fractures

ulnar exposure

radial exposure

volar approach

dorsal approach

distal radius

distal ulna