so the last lecture I went through the radiographic workup for acetabulum fractures right so ap x-ray jeu de views CT scans 3d CT scans and dynamic stress views when necessary and that comprises most of your radiologic workup so now we're going to talk a little bit more about classification and in the very first lecture of this series I mentioned that the classification by Judean letter Annelle is by and large the main classification system that is used today so it's very important I think that you understand the column you know anterior and posterior column representation of the acetabulum the walls of the acetabulum now the classification scheme by letter n' L and G day it falls into two types of the elementary and the associated types okay and the orthopedic trauma Association has also adopted this into its overall classification scheme so the elementary patterns include part or all of one column being fractured except for one type so the the the elementary patterns include the posterior wall fractures anterior wall fractures post your column fractures intercom fractures and then they throw in transverse fractures into this quote by virtue of its purity although it really isn't that elementary it kind of traverses two columns right but we keep we'll keep it in the elementary pattern group so here are the elementary fractures and I if you have a minute you should probably pause here really take a few minutes to look this over and understand the fracture types of course are many variants not every fracture not every poster wall fracture for instance looks exactly like this or every anterior wall fracture look like this but these are fairly representative examples I think you should understand these and of course these are all shown sort of from that you know that inverted inverted Y schematic where the acetabulum is that inverted horseshoe okay and that's how all these are shown that's all the figures that were to show throughout the remainder of this lecture are going to utilize right now The Associated patterns include the include at least two elementary forms so post your call and post your wall transverse and posterior wall t-shaped fractures anterior or column poster Hemi a transverse or associated both column fractures okay so those are the five associated fracture types then that makes up our ten ten fracture types for the classification and here the here in the next five right The Associated fracture type so posterior column post your wall transverse posterior wall t-shaped anterior you sent your column answer column posterior me transverse and associated both column fracture so a lot of characteristics here though the posterior can't post your wall essentially everything is happening posterior Li so when you treat these surgically you go posterior Li transverse with posterior wall because of the posterior wall fracture you pretty much have to go posterior on these t-shaped depending on how badly displaced it is and how much the joint surfaces involved at the Dome you may have to go anterior or posterior or both or some kind of extends I'll approach a lot of the dome is involved in order to reduce both at the same time and keep in mind as opposed to the transverse fracture type if you come posterior and control this fracture this fragment is this associated from this fragment so you cannot indirectly control this fracture from here so that's why to get direct control here you may need to come anterior I'll talk about the more that later and another important point is the associated both column this is the equivalent of an a type C parry articular fracture meaning all the articular fragments are dissociated from the sciatic buttress here okay this is that sciatic buttress and when all the joint fragments are dissociated in the static buttress it's an associate both column and if you look back every other fracture type has some joint surface associated to the sciatic buttress right here it is here here it is here here it is here you know here it is here if I go back and you can see in every single example some of the joint surface at least a portion of it is contiguous with the sciatic buttress okay except for the associate both column type a little bit about roof arcs I don't think you see them used quite as much anymore although many surgeons still will refer to these and you have to understand them for test-taking purposes as well it's an angle it's like a vertical line through the center of the femoral head it'll line through the fracture site so shown very nicely here straight line down to the center of the head and then out to the fracture site shown here and then that angle is your roof arc angle and it's a it's a way to help determine if the remaining intact acetabulum is sufficient to maintain a stable and Congress relationship with the femoral head okay so you're looking to see how much of that dome is involved so for instance like a very very low fractures of the fracture line came down here you know that would mean you have all this joint surface up here to potentially articulate with the femoral head so it's measured on all three radiographic views ap the obturator oblique the iliac oblique these are some of the numbers that you need to keep in mind also keep in mind it does not roof arc measurements do not apply to both column fractures or only post your wall fractures okay here's an example roof arc measurement shown here on AP view on an operator oblique view and then the iliac oblique view and you can see this treated and operatively it goes on to have some subluxation so let's go through some examples of the fracture types okay post your wall fracture is very common type involves the separation of the posterior articular surface the majority of the poster column usually is left undisturbed and a lot of times these are what you see when you have a posterior femoral head dislocation that is like a posterior hip dislocation takes a piece of the posterior wall with it okay and here's an example of that post your wall fracture and again majority of the rest of the poster come usually isn't term isn't terribly disturbed can to some degree be fractured more extensively there may subtypes right so all of these fracture types and electrical classification have subtypes but you have a fracture combo can find below the roof a posterior superior fracture involving the roof that goes way up that you may need more extensive exposure to get to a post your inferior fracture involving a subhadda lloyd groove I should say and fractures associated with marginal impaction very important concept for you to understand so the AP x-ray you might see disruption of the posterior Ram femoral head dislocation so there's an AP radiograph here you can see this some disruption of the posterior Ram but you really don't see it as well until you get judez views right so obturator oblique is your key view for looking at that posterior wall fracture displacement and then iliac oblique you're gonna recognize that you know that poster calm is not completely disrupted is it and you'll get to look at the answer wall so here's your same patient obturator oblique x-ray now you can see here's that posterior wall fracture and then you get your iliac oblique and you notice that no there's no fracture the OE area line is intact no fracture through there posterior column and answer our walls intact so let's look at this again and a lot of times when the femoral head dislocates it causes this fracture to come up here and you may have instead of the fracture being down here the fracture may be up here alright looking like this and then you have the so-called Gulf Sun Gulf sign is you know we have the arc of the source heal and then you have the posterior wall it looks like sort of like seagulls in the sky right the gull sign now very very important concept here I've referred to this about three times now marginal impaction right so CT scans will show you if there's a loose body so imagine this was a femoral head that dislocated re reduced small piece of the femoral of the femoral head or a poster wall or whatever is floated into the joint if you also see marginal impaction here right so let's take it a look at this so compare that to this side right here you can see the joint surface you know it was nice and congruent to the femoral head right here take a look here the femoral head oops the femoral head is here but the joint surface is here and why is that well because it's been impacted it's kind of like you know so when the head comes out this way it jams up against here and rather than snapping the piece off it impacts at this whoops it impacts it this way all right so let's just draw that out a little bit a little bit larger right so you have this right so this needs to be reduced out this way meaning you have to disinfect it you won't want it's almost like if you're doing a tibial plateau fracture you tamp it up you literally have to you have to get in here open free this up and then bring it out this way all right so this if you just take this posterior wall here and fix it back down you're still gonna have this big void right and this is not congruent and you're allowing this head to come back out again so you have to get in here or you have to get in here you have to bring this back up so that you end up with something that looks like this again okay as opposed to this being down here you bring it back up so you bring this surface back up and then you can bone graft behind it and very important markup accent you can also get it in the dome of the acetabulum with certain anterior column types and you will completely miss that on x-ray so that's where you really need to get CT scans to see that better what about poster column fractures he's actually a pretty uncommon Inlet Rennell series would to just have an isolated posterior column it's a disruption of the ischium and I'll show you some examples of where the fracture occurs there's medial displacement of the femoral head so here's kind of that fracture line this is a posterior column fracture so you know a lot of times patients have a post your wall fracture and it extends a little further down but it's not a true posterior column fracture right this is really a true posterior column fracture breaking the ilio issue line fracture through the joint surface and then this can exit down here it can you know have a little bit of a variable course but it looks something like that the EP alias reliance disrupted post your column is displaced medially typically put Illya pectin aligns intact right so look at this you look at this initially you think well maybe it's transverse fracture you know one of the more common fracture types you can see the femoral head does not look congruent it's traveling medially a little bit right right you can look at this and look at this that's that's not congruent compared to this side right you see this inferior segment it's displaced immediately right along with the head right so what do you go to your obturator oblique and your iliac oblique views right your judez views now very important here I'm gonna go back now if you look at this little pectin EO line is intact now again I said you may first look at this at first glance head it's going medial you see something going on here you initially start to think of something more common like a transverse fracture but that Elio pectin a-line is stone-cold intact right nothing going on there let's look at it again now you have an operator oblique view and it confirms your findings I mean look there's something going on here but this line is completely intact supposed to the posterior column showing on the iliac oblique view which is it's widely displaced so that's a posterior column fracture okay CT scan medialization of the femoral head post your column fracture all right anterior wall fractures where you have a disruption of the small portion of the answer roof in acetabulum usually the rest of the answer column is relatively undisturbed so you have something like this now interestingly if you think about it this is not the equivalent of the posterior wall fracture right puts your wall fracture typically you have just you know like excuse me sorry but that you have like something like you know a portion of the post your wall that's off here you're talking about something that really disrupts the entire answer column just to some degree right it's not like that little wall fracture like you get with a posterior but an anterior wall fracture usually looks more like this and you often involve the quadrilateral plate the Ilia pecking a line is broken at two points typically the anterior room of the astra where a stab wound was disrupted the femoral head rotates anteriorly externally rotates the ilium ischium line is intact okay so there's a lot going on but the only issue aligns intact and you may not completely understand that by looking at this x-ray but clearly the yo-yo pecked any line is disrupted hard to see the only airline but econo seems like it may be intact right there head is dislocated medially alright so this is a very typical fracture pattern you may see in a geriatric fracture pattern judez views you're gonna get a fracture of the anterior wall on the opportunity oblique but on the iliac oblique you can see the poster columns intact right so big time disruption here dislocated completely not congruent with the dome at all but on the iliac oblique view that shit'll line is relatively intact right or that that post your column line right it does not look there's anything going on what you have here is the quadrilateral plate here being pushed medially along with the femoral head and here you can see that right you have that so-called saloon door or you know yet the femoral head sort of barging its way through pushing the quadrilateral plate this way in the anterior wall this way and that's a very common common fracture type I guess that you'll see in a lot of geriatric fracture patterns now and your whole interval fracture variant is basically this the equivalent of the posterior wall but this actually is very uncommon it's a pretty rare fracture type you may see it with a front with an anterior hip dislocation so if you think about how often you see those that's about how often you'll see these compared to posterior walls so you're not gonna see me I might look something a little bit like this okay answer column fractures there are a lot of fractured subtypes because of all that iliac wing that you have that is included in the anterior column so the fracture line can exit at so many different places you've got a very low fracture type a low fracture type intermediate fractures up high fracture type so these are all those you know sort of variable locations for the for the fracture line that goes through the iliac wing but these are all if you think about it all ant your column fractures right just like the posterior column fractures come this way all right or or this way or something the answer column fractures come this way right so there's one type here here's a higher fracture type here and then as a really high one where it goes all the way splits the iliac wing comes down but it's really you know the poster Calmes intact right it's the answer column that's involved okay this rock disruption of the opec Tennille wine fracture of the issue pubic ramus so here you can see on the right-hand side something going on Ilia pectin ii online doesn't quite look right okay it seems like the Ilia issue oh I might be okay right Ilya pectin you line comes here and then it kind of goes here so something's not quite right obturator oblique will clearly show this to you we can answer column displacement of the femoral head the iliac oblique post recombinant tactics of you may see some associate quadrilateral plate fracture so here's that anterior column on the right hand side so you have a little bit of Russian on this particular x-ray shown here you'll see the fracture line extending sometimes through the iliac wing but the posterior column is relatively intact and here you can see you know hi answer column fracture coming through the iliac wing and down through the answer column with the acetabulum and the last of the elementary types is the transverse fracture the so-called included by virtue of purity right but nevertheless it involves both columns answer and post your call its sub classified based on the level of the factor through the acetabulum that is where it is relation to the dome so you have some sorry so you have the fracture essentially these transverse right so you have your you know your again you have your inverted Y picture the horseshoe sort of sits like this and the transverse fracture basically comes right across right so and depending on whether it comes across up here or down here or somewhere here that's where you have these subtypes right Transtech tells a fracture through the roof very critical they get it reduced nicely juxta tectal is through the highest point of the colloid fossa and infra tectal is through the cauda lloyd fossa okay so Transtech told much more important that you get a perfect reduction and protect a less critical okay and then here it's kind of shown again all right on the AP radiograph both lines are disrupted right where both columns are fractured illya packed in a lily is real wine the anteroom and poster rooms are disrupted here you have a minimally displaced but there's a transverse acetabulum fractured you can kind of get the impression looks like both lines are disrupted judez views are gonna show you the fracture orientation very nicely it should as opposed to a t-shaped should confirm that does an uninjured obturator ring okay that distinguishes it from the t-shaped fracture and the iliac oblique you're gonna see potentially fracture the quadrilateral now surface are where it goes through so here you see opt aerator oblique you have the fracture line visible right about here iliac oblique you can see the fracture line visible right there coming through right and you have the fracture demonstrated here right kind of running running from front to back anterior to posterior well the CT scan you should be able to pick up on that transfer as fracture pattern and just make sure you don't get fooled like I said in one of the earlier slides 2d axial CT scans can be very confusing unless you're really comfortable tracking them up and down okay and you really got also rely on your radiographs and a 3d recon I think to make sure you don't mistake this for like you look over here if you just look at this that this one image you you may think there's a posterior wall fracture but you really have to track it up and down see where the rest of that fracture line is and then put it all together okay so if you put it all together you here you can see it's a transverse fracture alright so I'm going to stop there we'll get into the Associated fracture types and finish out this lecture on acetabulum Anatomy classification in the next set of slides Thanks