Computer generated transcript

Warning!
The following transcript was generated automatically from the content and has not been checked or corrected manually.

A few small things here and there. Ok. So today's talk is about the hand and wrist and what we will be covering in today's talk is uh we will recap the anatomy of the hand and the wrist and this includes talking about the bones, muscles, nerves. Um Following on to that, we will briefly talk about some X ray imaging of the hand, which is something that uh I'm sure many of us run into quite commonly both in A&E and um wh doing work on the wards and of course in theaters. So we will look at some normal hand x-rays and talk about the key things to look out for on the imaging. Following on from that, we will talk about um specific examinations of the hand and um that will include some special tests as well. Ok. So to start us off nice and simple, um let's recap the anatomy of the hand. Um We will begin with the bony anatomy as we can see over here. Um This diagram kind of talks you through the main bones of the hand and wrist. Um There is essentially several parts to this. You have the forearm section which is just located low down here. And you can see that it's obviously made up of the ulnar and the radius bones which come to which form a part of the wrist joint with the carpus, which contains all of your carpal bones just over here. Um Yeah, these then articulate with the metacarpal joints, uh which altogether make up what's called the metacarpus. And lastly, you have the phalanxes, um which are all quite consistent from the second to the fourth um metacarpal joints. Um So the uh index to the pinky finger, um all of these have three pharynxes, the proximal, middle and distal pharynx and your thumb only has two which is the um proximal and the distal. So all nice and simple things um counting metacarpals as well. Um starting from the thumb, which is just over here, you go from 12345 and you have of course, the um carpal bones there. So, looking at them in a little bit more detail, um the carpal bones themselves form broadly speaking, two rows. Um and you have a proximal and a distal row each containing four bones here. Um starting uh er most medially and then moving lateral er sorry, starting most laterally and moving more medially. You start off with the scaphoid, the lunate, the trl and the pisiform in the first row. And again, same direction we go from the trapezium, the trapezoid, um the capitate and the hamate with its little hook. Um in normal kind of people and anatomy, you can palpate the um the hook of the hamate by um just pressing just above where your palm meets your wrist and you can actually feel that little burning prominence there. Um Essentially the reason why these bones are important is because they form um a gully or a canal. And this, you can see in this image here, um this canal or well carpal tunnel um is formed by a fibrous sheath um which uh covers uh which forms a roof of the um canal essentially. And that is called the flexor retinaculum um there. So beneath it, you have the tendons and namely, you have the uh flexor digitorum superficialis and um flexor digitorum profundus tendons over here. And of course, very importantly, you have the median nerve which just sits nicely in that canal there. Um Fine moving on. Um We have a little bit more of a detailed diagram and this again just helps to, to visualize the flexor digitorum superficialis which sits superficially compared to the flexor digitorum profundus, the deep flexor digitorum tendon. Um And these pass through into the palm of the hand now because they don't originate within the hand. They are not considered an intrinsic part of the hand there. The other important structures that are worth noting uh within the wrist. Um We have the radial artery which passes um on the lateral or the radial side of the carpus and proceeds dorsally into the hand as you can see on this diagram here and illustrate it just over here as it passes posterior laterally to the trapezium. Here. On the medial ulnar side, you obviously have the um ulnar nerve and the ulnar arteries. Um they are passing superficial to the flexor retinaculum, which you can see here is this layer over here and um they pass through a structure known as Gus can canal. Now, um you also have the um Palmaris Longus tendon which er passes through er passes superficially to the flexor retinaculum. It goes on to form a part of the palmar aponeurosis, which is not fully seen in this diagram here, but you can appreciate the, the tendon just over here. Um This uh the, this is of interest uh in some pathologies later on. Now, the other importance of the palmaris longus tendon is it's one of the most commonly harvest tendons um as it's um quite a useful tendon um to based on its length, its strength and other factors. Um The other thing about this tendon is that it's missing in approximately one quarter of all people with some variation based on ethnicities. Um its absence or its removal does not actually confer any reduced grip strength um but can reduce pinch grip strength in the 4th and 5th digits. Um hence its use for um harvest and other procedures. Now, um what we're going to do is we'll briefly look at the fingers and we will talk about the insertion of the flexor digitalis superficialis and Profundus tendons onto the uh phalangeal joints of the fingers. So here, I hope you can appreciate um that um both the F DS and the FDP, the flexor digitorum superficialis and the flexor digitorum profundus pass through some structures which are highlighted just in, in blue and uh red over here. Um F DS uh passes as a single continuous structure but you can see it bifurcates as it reaches the uh proximal phalanx and splits into two sections which both um go outwards and then insert onto the mi middle phalanx. Um FDP passes uh deep to F DS and then it actually penetrates through this gap that is formed and goes all the way to the distal fallings where it ultimately inserts. Um these structures that both of these tendons pass through are a set of pulleys. Um The annular pulleys highlighted in blue and hence labeled a one through a five going from proximal to distal and uh the cruciate pulleys which are the little cross shaped pully labeled C one to C four. Um Putting this together, it means that the main flexor of your distal phalanx is the FDP. Um uh and the F DS uh produces more flexion at the proximal interphalangeal joint. Um Yeah. The importance of this is for conditions such as trigger finger um where localized inflammation and swelling of the flexor tendon means it cannot smoothly pass through these pulley systems and cause catch it and causes the tendon to catch effectively, creating a kind of fixed flexion deformity, depending on which tendon is affected, you can see it in different portions of the finger. So moving on, we will then talk about um the intrinsic muscles of the hand. So these are broadly speaking, split into three main categories or three main groups. You have the thenar muscles which are grouped around the thumb just over here. And these include abductor, pollicis, brevis, flexor pollicis, Brevis and Opponens pollicis. We then go into the hypothenar group, which is this group over here on the ulnar side of the palm. And those include the adap to digiti minimi and the flexor digiti minimi and opponents digiti minimi. Um All quite intrinsically linked with the mini or the little finger there as a helpful memory aid, metacarpal group which sit around the metacarpal area. Just here, you have the lumbrical muscles which you can see labeled here. Just the little muscles all here inserting onto the phalanges here. Um The palmar interossei, which you can't quite appreciate on this diagram here, but you will see a little bit of a better picture later um and the dorsal interossei as well. So um here, the main thing for me to say is that all of the intrinsic muscles of the hand are innervated by a single nerve. Now, does anybody know which, uh, well, all except a certain group. Oh, sorry guys, I just realized that the slides are not changing. Um, are they still not changing or are they? Ok. One second. Sorry guys. Can you see the sls changing now? Ok. Sorry about that. My bad. Um, basically, where were we? Apologies for that? Um, I'm not as good at computers as I thought. Um, so, uh, talking about bony anatomy, uh, we'll, I'll just quickly run through those same slides. So, um this was just the things that we were talking about with regards to the anatomy of the bones of the hand. I'm sure this is uh something that is familiar to just about everybody. Um Here again, talking a little bit more in depth about the kind of rows of the um carpal bones here and looking a bit more in detail at the um canal hand tendon missing, you're saying? Um So here we're looking at the um finger tendons, the F DS and FDP over here and the next one is looking just over here. So, um this just talks about the um muscles of the hand. So if we go back to uh talking about the, the different muscles, um pretty much most of the muscles are innervated by one singular nerve and that nerve is the ulnar nerve. Now, there is four muscles um that are not innervated by the, by the ulnar nerve. Um Does anybody know which muscles those are if you can pop a quick message into the chat. Yep. So I'm seeing some responses. So the loaf muscles um and the interossei um interesting. Yes. Good, good, good choices, good choices. So, um who, whoever said loaf well done? Um I uh they are indeed the loaf muscles. And uh do you want to? Um Yes, here we go. We've got the breakdown of them. So we have the lateral lumbrical and specifically, that means the outer two lumbrical. So the ones on the radial side here. Yep. Um We've got the opponent's pollicis, um the big muscle over here and um the adductor puls brevis as well. Um just coming in here and the flexor pulses, brevis there, good. Um Basically, you can see that all of these muscles uh pretty much sit within the uh thenar group grouping. And um the main reason for this is because they are innervated by the median nerve, which if you remember from the previous diagram comes through on the radial side of the carpal tunnel and innervates the 1st 2.5 digits, um both sensory and musculature wise. So, moving on, we have now the dorsum of the hand. Um And here, the anatomy is a bit simpler. Um The only intrinsic muscles present here are the dorsal interossei, which you can see just sitting over here and the um adductor digiti minimi just over here, which you could also see at the uh palmar aspect but is a bit more pronounced on the dorsum. And uh those are the only intrinsic muscles. So, muscles that originate within the hand and act within the hand. Um The rest of them um actually originate in the forearm, as you can see here and connect via long tendons um uh to produce their extensor effect. Um Fine, we won't dwell too long on this. Um And just, we'll quickly talk about a brief overview of the nerves of the hand here and here. Uh We're talking about median nerve which as we mentioned, innervates the thenar muscles and the lumber, the lateral lumbrical, the 1st and 2nd 1, cutaneously innervates the lateral two thirds of the palm palmar surface and dorsal uh distal aspect of the third of lateral 3.5 digits. OK. Um A bit of a confusing thing but I uh we, we but essentially um just covers small portion of the dorsal side of the er digits there. Um The ulnar nerve mainly uh innervates the hypothenar intraosteal muscles and lumbrical. So pretty much all the um more or less uh intrinsic muscles of the hand there and cutaneous innervation as you can see here um covers the medial third of the palm, um the palmar and dorsal surfaces of the 1st 1.5 digits of the medial 1.5 digits. OK? And lastly, you have the radial nerve um which largely innervates the extensor compartment of the hand as well as a part of the abductor pollicis Longus. OK. Fine. Let's move on now to the imaging. Um So here uh we have a x-ray radiograph of the hand. Now, um does anyone wanna offer any comments on to whether or not at brief glance this looks normal or abnormal? Ok. It doesn't look like we have any takers, but that's fine. Essentially. Um X rays. Uh In this case, this is a completely normal radiograph of the hand and you can see it's the right hand here. Um abnormal scaphoid, uh fair enough. Um in this situation, uh it is actually normal although there is a little enhancement over here. Um That is, I think just a bit of um shadowing there that appears. Um but actually, uh otherwise it is completely normal. Um Basically the main thing to look for this thing uh on x-rays is check for alignment, make sure that all of the um uh phalanges are aligning with each other, aligning with their metacarpal um counterparts. Um And everybody has a slightly different structure for this. Um But in general, um yeah, it's, it's about looking at the alignment here, uh alignment in each individual finger and then trying to appreciate the different anatomy within all of the different bones. Um important to note uh of the four bones here. Um the uh trichy TRM and the pisiform will be superimposed over one another. So it is a little bit difficult to appreciate each individual one there. Um Yeah, looking at a slightly more oblique view. Um oblique views are important because they give you a slightly different view of the fingers and can help you appreciate any kind of deformities that might not be visible on a plain AP film. Um Essentially uh the main thing to look out for here is that the midshaft of the third to the fifth metacarpals should not overlap. And if they do that may uh indicate a dislocation or some kind of other deformity there, um there is some overlap of the distal heads of the third to fifth metacarpals, but you should still be able to appreciate some of the anatomy there and there should be no overlap of the first and the second head uh of the 2nd and 3rd, that's carpal heads. Um OK, looking at the um carpus once again. Um this is just looking at the er bones in a bit more detail and you can see here, number one is where you would expect the scaphoid to um lunate, um trich and pif form over here. You can see the uh triet just posterior here and the PS form super ID over the top of it, um moving on to the others as well. Um the uh trapezoid and the trapezium, uh the capitate and the hamate with its little hook protruding outwards. Um Those are the main things whenever you see the scaphoid, you might see this little enhancement here. Um And it's very hard to appreciate uh scaphoid fractures on just plain radiographs, which is why there is guidance now that if there is strong clinical suspicion, then that should be um the most appropriate thing to do in that case is probably go to CT rather than doing serial radiographs. Um Hi, you. Ok. So um looking at this x-ray, does anybody wanna tell me what they think? Um they can see here and we will flash a um a lateral view as well a little bit later. Yeah, so I'm seeing fifth finger um comments come up good. Yeah, so you can see that there appears to be some disruption around the uh fifth uh proximal phalanx just over here. Um doesn't look very normal there. You can see some cortical disruptions. So if we bring up the lateral view, uh you can see uh there is also yes, degenerative changes, you can see some uh degeneration there um For sure, very good. Um But talking about the uh biggest abnormality there. Now, on the lateral view, you can appreciate that there is a small course called break here with some minimal displacement of the um fifth um proximal phalanx over here on the uh on the on the fifth digit. Um Now, within our faith, I hope you can also see that there is a little deformity here of the distal phalanx, particularly at the intraarticular surface where there seems to be a little disruption just over there. Um And that is a little avulsion fracture as well. All this goes to show that basically with hand x rays, um, it's important to really just systematically go through all of the joints um in multiple um, views. Uh because it's the changes can be quite subtle and uh quite hard to um locate sometimes fine moving on from the imaging section. Um We will briefly look at uh the examination of the hand and wrist and essentially like all the examinations, they follow a pretty predictable pattern. Um where we look feel and move the joint, we examine the joint above and usually below. Uh we don't have a joint below in this situation. And uh we do any other special tests that are necessary. So when we look at the hands, obviously, we want to inspect both hands even if only one of them is affected. Uh because that can sometimes give us clues to um asymmetry um and things like that. Uh Yeah. Um Then the other thing as well is we are looking for things like swelling, deformity, any evidence of muscle wasting, um any changes to the nails in particular and also something I didn't mention here, but any skin changes of the hand as well because um skin diseases can sometimes um manifest with um arthropathy involvement particularly in the hands. Um And obviously you want to inspect the elbows and the forearms as well. Um Again, looking for any skin changes, looking for any obvious deformities there. Um feel uh you want to perform a detailed examination of the joints. Um, people have different uh strategies for this but one common uh thing is to almost use a couple of your fingers as a little s to form a little C and then palpate all the individual um, smaller, er, p er in interphalangeal and uh metacarpophalangeal joint of the hand. Um, you can palpate the scaphoid through the anatomical snuffbox, which I which it can be appreciated by just extending your thumb into a thumbs up position and feeling the little groove that is formed by the um abductor tendons and the extensor tendons um of the thumb. Um you want to feel for any heat, you wanna look for any um swellings within the hand, any tenderness and obviously palpating for pulses and assessing light touch sensation. Um And lastly, you want to move the hands. Now, wrist uh is quite, quite a simple joint in the sense that it's uh mo i in in terms of its movement, it does flexion to 90 degrees, it does extension to roughly 90 degrees and it can do a little bit of abduction and abduction or um ulnar deviation and radial deviation. Um Those movements are quite straightforward. Um Similarly, with the finger movements, we all know about flexion extension, abduction and abduction. The thumb is where it gets a little bit more complicated where thumb abduction is movement of the thumb away from the plane of the hand. So if you hold your hand out in front of you, um and you hold it flat on, on a moving the thumb out of that plane so upwards and that is um abduction and again, moving the thumb back towards the palm that is abduction, whereas flexion and extension is essentially moving in the plane of the hand. So doing your thumbs up is a extension motion of the thumb. And lastly, you wanna check for opposition. Um So it is the patient able to oppose all the digits to the thumb and likewise test the pinch grip strength, talking a little bit about special tests. There's a few that we can talk about and they're all used for slightly different contexts. Um namely um looking for carpal tunnel, looking for teen sinusitis, looking for inf signs of infection. And these are the ones that I've chosen to cover in this topic. There are of course some other tests that you, you can perform depending on the um pathology that you see at hand and the um suspicions there. Um But these are the kind of main ones that are probably most common to use. So Tinel's test um basically is a test for carpal tunnel. The idea is that you locate the distal wrist crease. So one that you can just see over here and just above where it makes its little um bump, which should be quite um quite central in the palm if you tap just above that area for a few seconds. Um If the patient suffers from carpal tunnel, it should reproduce the pain that they are usually felt. Uh And that would be considered a positive finding. So that is Tinel's test. Um quite good for um for diagnosing um carpal tunnel, however, not always perfect. So for that reason, you also have falls test, which tests very similar things uh test again for carpal tunnel. And you've got the, it's also called the reverse prayer sign. So with both of the wrists in full, uh 90 degrees of flexion held together as you can see just over here, um you hold that for about 30 to 60 seconds and any reproduction of the pain is again a positive finding. Now we're gonna go on to a slightly more in depth test, Finkelsteins test. Um And this one is looking specifically for Decor's uh 10 Synovitis. Basically, the idea here is you hold the wrist in a fairly neutral position um in a uh in not a fully er pronated manner, but a kind of su half supernate, half pro neutral position. Um And ideally, you can suspend it over the side of a bed or a table. And the classical test is for the examiner to just grab the thumb and pull downwards. This kind of stretching motion will uh stretch um the uh tendons just over here and reproduce pain particularly in the acute phase of the disease. Usually. Um this will then um this elicitation of pain suggests that there is a possibility of some Tinti there. Now, um you can also do this uh by asking the patient to uh by either just holding the hand and pointing it again into an ulnar deviated fashion or by asking the patient themselves to uh grab the thumb and ulna deviate. Um they're all equally as likely to elicit the same response. And lastly, um we have canel sign. Now, this is more of a um sign that you see in acute hand infections. And it's quite important to uh use to distinguish from upper limb cellulitis because this, these signs and these cardinal four components of the sign would then indicate that there is a flexor tendon sheath infection. Um This is uh much more serious than just a simple cellulitis and may require sort of immediate washout and debridement and such so important to look out for these. And usually the, well, the, the the hallmarks of can sign the four components. Um affected finger is held in slight flexion as you can see here. It's just a very slight flexion there, there's fusiform swelling over the affected tendon. So you can see it's, it's ballooned up and looks almost like a little sausage. Um There is definitely going to be a lot of tenderness over the affected tendon feeling all the way down up to the carpal tunnel sometimes and there will be quite a lot of pain and passive extension of the finger. So these are the kind of main signs there. Now, um that was a whistle stop tour. So, uh I'm sorry if that went a little bit quick. However, um that is all for me today. Um Let me know if you have any questions. Thank you everyone and I hope you have a nice rest of your day.