When you think of the wrist, there are essentially two rows of carpal bones: the proximal and the distal Capraro, and each Capraro has four bones in them. The proximal Capraro comprises the scaphoid, lunate, and triquetrum. The distal Capraro comprises the hamate, capitate, trapezoid, and trapezium.
On the Volar side of the proximal Capraro is the pisiform. Now, these are joined together by thick ligaments. Essentially, these are ropes holding the bones together. So when we think of the distal Capraro, we have the trapezoid, tropism ligament, we have the capitate, trapezoid ligament, and we have the capitate, hamate ligament. And these form robust interconnections between the bones.
WHAT TO LOOK FOR
The majority of the pathology, however, where we see ligaments are in the proximal Capraro, and the two most important proximal Capraro ligaments are the scapholunate ligament and the lunotriquetral ligament.
The surface anatomy is critical when examining the hand wrist. Just by taking your finger, using tactile motion, you can delineate pathology. Think of this as an iceberg concept. Whatever you see on the top row, you have to go deeper into, as this is where your pathology really lies.
Usually, in orthopedics, we're taught to look, feel, and move. I use the acronym Stand.
(S) stands for the Skin. Look for any scars, any lacerations, any bump for any bruises, because that can indicate where the pathology is.
(T) is the tendons, and these are the ropes that allow you to move your fingers. And it's important to specifically identify and examine each tendon.
(A) is for the arteries, which are essentially the pipes that give you the blood supply to the hand.
(N) stands for the nerves. Now we have important motor and sensory nerves that we need to examine.
(D) are the dynamic maneuvers that you need to critically look at the areas of pathology.
DORSAL HAND ANATOMY
Now, when you think of this in terms of the dorsal hand anatomy, if we've taken the skin off, you can see this nice kind of dissection by Mark Garcialis where he shows us those ropes, and those ropes are contained into six extensive compartment tendons here. They're labeled the first extensive compartment is the EPB and the APL. The second extensive compartment is the ECRL and the ECB.
The third extensive compartment tendon is the EPL, which has a curvilinear course going ulnar to bony prominence on the dorsal radial aspect of the Calista's tubercle. The fourth extensor compartment contains the EDC tendons that move the index long ring and small finger. But the index and small finger also have independent accented tendons, namely the EIP.
The fifth extensor compartment is the EDM that moves the small finger. And finally, the ECU is the sixth extensor compartment tendon, which is the only extensive tendon that runs with the ulna.
We've opened up the extensor at Nakhla, which is that lining that covers all the extensive tendons. And you can see the ECU runs with the ulna and its ECU subtree.
Now, we've removed the extensive tendons out of the way, and we've opened up the capsule, which is the lining of the joint, and we've released this from distal to proximal. As we peel this back, you can see the carpal bones and, through the live examination today, we'll show you how to independently assess and feel for these carpal bones.
It can be overwhelming when you examine the rest. There are so many structures to examine. How do you do this in a sequential, systematic method?
BEST METHOD FOR WRIST EXAMINATION
So what I like to do is divide the rest into thirds. Essentially, if I take a line and draw it along Lister’s tubercle, you have a lot of tendons and bones to the radial side of the line. And for example, the scaphoid proximal pole is the first bone that we'll examine. Now, if I draw a line along the DIUJ, you'll now have pathology, basically radial to that line. That's namely the lunate, which is the most proximal bone, and we'll show you how to do that. When you go ulnar to this line, you now have the ulnar carpal joint.
So now, if we look at the schematic, what are we looking at? Remember I told you about that dorsal structure being Lister's cubicle? That's your gateway to the wrist.
So if we come just distal and radial to Lister’s cubicle, radial to that line, you'll feel the proximal pole of the scaphoid. If you go between that Lister's cubicle line and the DIUJ, you'll have the lunateBlue Knight and just ulna to that line, you'll have the Destil on that. It's that specific. As we come distal to this, you'll see the ECU tendon, and the most dorsal ulnar structure in the wrist is called a triquetrum. That is an important structure because sometimes you can get lost. But if you can find this bone, you can feel your way around the wrist.
Now, just distal to the triquetrum is the hamate. Between the hamate and the trapezoid is the capitate, and that is collinear with the lunate. Now, radial to the capitate, is the trapezoid and then the final bone is the trapezium, which is adjacent to the thumb metacarpal. This is critical because a lot of patients come in with basal or thumb joint arthritis.
EXTENSIVE COMPARTMENT TENDONS
The second extensive compartment comprises the ECRM, which inserts into the radial base of the index finger, and the ECB, which inserts into the base of the long finger. And these tendons essentially come from the radial aspect down. Now, as they come down, they are called the outcrop, and they're covered by the first also compartment tendons. So sometimes patients will come in and point to pain in this area here. And that's called intersection syndrome, where those tendons run under the first auto compartment.
And the beauty of the hand is that most patients can come and pinpoint with one finger where their pathology is. And so, if I would flex her wrist down, that would essentially cause some discomfort in this area here. Another way to examine these tendons is, as she pulls a wrist hardback, you can feel these tendons firing. And this is the ECRL and the ECLB and just relax.
The third extensor compartment is called the EPL or Extensor Pollicis Longus. The easiest way to delineate this is, if the patient touches their thumb to your finger, you can see how they extend at the IP joint, and this is where the extensor tendon runs – ulna to the Lister’s tubercle.
Now, what is Lister’s tubercle? Lister’s tubercle is a bony prominence right at the back of the wrist. And this is important because everything just radial to this is a second extensive compartment and just ulna to this is the EPL. The actual tendon runs in this sort of curvilinear manner, ulna to Lister's cubicle.
The fourth extensor compartment is essentially the extensive indices prepress and the Extensor Digitorum Communis or the EDC. Now, the index finger has to extend to tendons. Eleanore, if you make a fist and raise your index finger up, that is the EIP. So she can independently extend the index finger. Now, what I want you to do is raise up your pinky, that is the EDM, or the extensive digital M.E. of the small finger.
This also has to extend to tendons and the course of the extension to do the minimum runs literally over the deluge, which is right here. So some patients may come in with pain over the DOJ and it's important to examine the extensive tending to the small finger because they could have pathology over this as well. So now if you raise your index and your small finger together, this is the tip of the index finger, the etm of the small finger. Now, if she raises all the fingers, that's the EDC.
We've examined the IP to the index finger, the ETM, which is the first extensive compartment, and the fourth extensive compartment tendons also to these fingers. The final extensor tendon is called the X or the extensive copy honoris, which essentially runs from the lateral aspect to the elbow all the way down to insert in the base of the fifth metacarpal.
Now, this is a very important tendon because it's the only extensor tendon that independently runs with the owner. And it's important As the radius, the compass in their hand or rotate around the ulnar, and the ulnar is a fixed unit of the forearm that allows supination.
The next thing is the nerves, and there are too many nerves to examine. We have the dorsal sensory branch of the radial nerve, which you can see goes to the thumb index and long and the radio, both of the ring finger and the dorsal sensory branch of the ulnar, which is this green nerve that runs to the small finger over here.
It's important to examine this because sometimes patients will come in with pain or they have difficulty, for example, putting a watch on or putting their sleeve in their shirt because it can irritate the nerves in this region. So, when I look at Elon's hand, I'm looking for the dorsal century, varnish of the radial nerve. Do you have any tingling or pain in this area?
What I will do sometimes if I tap and that's called a Tinel sign to see where they're maximally tender. Now, if somebody, for example, has sustained a superficial laceration underneath the skin and it was close, but they have pain in this area, you worry that sometimes they may have cut that nerve. The second nerve is to look at the dorsal sentry branch, the nerve that runs from volar to dorsal giving innovation and sensation to the back of the hand on the side. And again, she has a normal sensation.
The next thing is D. D stands for the dynamic maneuvers of the hand and wrist. And this is critical because oftentimes when patients come in with pathology, it's really important that these specialized tests are performed to delineate the pathology.
So if we look at Ellen's back of the hand, essentially I'm going to divide it into thirds. So remember, I talked about Lister's tubercle. So this tubercle sits right about here. If I just draw up a longitudinal line list cubicle, I think of everything radial to this. I then draw another line along the distal, ready on a joint or the Dugway, which runs here. So now essentially I've divided the rest into thirds. I have the radial third, the central third and the ulna third.
And that is important to know because in each third runs different bones and different ligaments. So in my mind's eye, I've drawn the lines down. So now what I'll do is I'll take a rest, and I'll gently flex this at about thirty degrees of flexion because that brings all the dorsal carpal structures to the surface. So the first thing I want to feel is, the Scaphoid said. Now, I found this cubicle, and I've slightly flexed, and this brings up the proximal pole of the scaphoid right here and so I'll press right here. Any pain or discomfort in here?
OK, so that's how Scaphoid is now. Remember, I talked about that line that this is tubercle. If I come straight down this line, there is the Fallon ligament and that is a critical structure to appreciate. This is a structure that's commonly injured when somebody has a wrist sprain and the x rays are negative and yet they continue to have pain in the wrist. And this is a scaffolding ligament injury, which would be in this area.
So now we're going to examine the trapezius. So if I take her thumb and wiggle this up and down, this is essentially the thumb metacarpal. And when I press right here, that is a tropism. And this can be very, very tender for patients of Basilar thumb joint arthritis, because usually what happens is that the thumb metacarpal subluxation docility, and by pushing down here, you are essentially reducing that arthritic joint which causes pain.
The next thing I want to explain is the scapegoat shift. Now, what is this? Now, when you have scaffolder ligament pathology, this is essentially a nice test to delineate Skaife Allouni problems. Now, normally what happens when you only deviate the wrist, the scaphoid is extended, and when you really deviate, it goes into flexion.
Now, when the Kefalonia ligament is injured, when you go into radial deviation, and if you put your thumb on the distal pole to the scaphoid, it will prevent the flexion of the scaphoid. And a result, you can drive the scapegoat out of the back of the wrist, which causes pain and clunking.
Now, this can be a painful test and the patient with Kefalonia ligament pathology. So this is probably one of the last tests that you want to do when finishing the exam.
So my thumb is on the distal pole of the scaphoid. My index finger is on the back of the scaphoid. Now, in unlar deviation, the scaphoid is extended when I go into radial deviation at flexes. So, for Eleanor, who doesn't have any pathology, this will be a normal examination. However, with pathology, patients will have pain and clunking at the back.
So what I do is take the risk from unlar deviation to radial deviation and my thumb feels scaphoid flexing. Now with a ligament injury, my thumb would block the scaffold from flexing and it would cause pain and clunking at the back of the wrist.
The next structure to examine is a ligament, and this is an important ligament on the other side of the wrist. And essentially there are three key tests to delineate this. The first is the compression test described by Dr. Lynch. And essentially what you're doing is compressing the creature into the loonie and seeing if that's causing any pain or pathology.
Essentially, what you're doing is stressing the joint in different planes. So one of the tests is called the linch compression test. And what we're doing here is that you can take your thumb and basically push the triquetrum from next to eliminate trying to cause pain in that direction. So is there any pain in that when I'm doing that?
OK, the second test is the Shiatsus described by Dr. Kleinman. And what you're doing here is taking your thumbs, trying to rock that lunar structure joint back and forth, and see if you're causing pain by the inflammation within the joint.
And the easiest way to do this is you take your thumb on the palms side and your thumb on the opposite side. And essentially you're sharing the Lety and seeing if that causes it. Any pain and in her, she has no pathology and that causes no pain.
And the third test described by Dr. Regan is a shock test. Essentially what you're doing is that you're holding the rest of the campus together with one hand and you're moving the joint back and forth. And again, that shear is trying to elicit joint pathology.
So I basically stabilized the whole wrist with my right hand. So the radius and the corpus in the hand are secure. Now I take my thumb and my index finger of my left hand and there, on the piece of foam and then try and remember, the triquetrum is the most docile, almost dropped from the side of the wrist, opposed to the distal owner. And I'm basically sharing it back and forth. And this is called the shock test.
NEUTRAL SUPINATION AND PRONATION
So, we look at this neutral supination and pronation, and it is critical that you examine the contralateral normal side and then examine the injured side because you can pick up subtle instabilities in that way.
And usually this is the last thing that I will do, because most patients with all the pain, they hurt in the region. So this will be the last exam that we will do. So just relax for me. So what I've done is I'll just take the dog, and I'll rock it forward in back and forth in neutral. So this has had a normal state.
Now, what I've done is I rotated, arrested in supination, and essentially with my left hand. I've got the coppice and the radius ulna. So the only thing that can move in this area is the DOJ. So we examine the DOJ neutral now in full supination, I rocket back and forth.
You can see how stable that is. And then, finally, I'll test it in pronation. So in full pronation.
Now I'll move the distal ready on a joint back and forth and you can actually see how it's a little bit more unstable and pronation and neutral and tightens up and supination. The last headset I like to do is call the owner impaction test now sometimes in full pronation. The owner is relatively longer than the radius and some patients will come in with only pain, complaining of pain right here when they forcefully grip.
So what we've done now is maybe only. Relatively longer than the radius, and what I'll do is essentially shift the only carpal joint into the distal, only seeing if that causes any pain. That's called the ulnar impaction shiatsus that I'm pushing against here.
OK, so now let's look at the palm side of the head. Now, you can see with this hand model next to Alan's hand, you can see once we've taken the skin off, there are numerous structures here. And all of these need to be carefully examined.
You can see in this model here, the yellow nerve is called the median nerve. The green nerve is called the only nerve. You can see this restructure. This is called the regulatory that goes and that the accompanying ulnar artery, which feeds into the superficial arch, which gives blood vessels to the fingers underlying these structures, you will see these blue structures.
And these are the ropes. These are the tendons that allow you to move your fingers. So now we're sequentially going to examine these structures to rule out any pathology.
So when we look at these common landmarks, we've taken the skin away. You'll see the most proximal aspect of the underside of the wrist is powerful. And then if you go just distal and radial to this, or if you take your thumb and put it on the form and press aiming to the index finger joint where your thumb tip rests, that's on the hook of the Hamate. And then we'll go radial and then you'll feel the distal pull to the scaphoid and just distal and radial to the scaphoid you'll feel the trapezius.
And that is an important landmark, especially with patients like Basilar thumb joint arthritis. Again, let's go back to the acronym of Stand. We want to look for the skin, see if there's any pathology. We're going to sequentially examine the wrist flexes and the finger flexes.
PATENCY OF RADIAL ARTERIES
We're also going to test the patency of the radial arteries. We're going to examine the nerves, the critical nerve to examine the median and all the nerves. And then finally, we're going to do dynamic tests.
So when I look at the skin, I'm looking for any scars, any swelling, any bruising, any lacerations. Clearly, she doesn't have anything that I'm going to examine the tendons. And I think it's important to sequentially do the wrist tendons and then the finger tendons. So when I look at the wrist tendons, there are essentially three tendons. We have the F.C., your tendon or extensive copy honoris. We have the Palmeiras longus tendon or the pull in some patients that are absent. And finally, we look at the flex – a copy radiology or the FCA. So what I want you to do is make a fist and pull your wrist back as hard as you can. Pull it up, up, up, up. So you can see here is her. I can palpate her for you.
And this is important to palpate because as you can distally remember, the form actually inserts within the few tendons. So sometimes patients can have patriarchal arthritis or F.C. tendinitis and just relax. Now, what I wanted to do is to pull your thumb, your small finger, and pull your wrist back again. Here you can see how Palmeiras longus tendon essentially has minimal functional relevance.
We tend to use this actually if we need a tendon, graft, the surgery and just relax and I'll make a fist and pull your wrist up and to the side over here and here you can feel this is her FCI tendon. Her tendon is immediately radial to the Palmeiras longus tendon, inserting into the base of the index finger metacarpal. And just relax.
Now, one of the common pathologies in hand clinics is something called trigger finger, and trigger finger is where the finger gets locked. Now, the tendons, which are the ropes that help you bend your finger, essentially glide through little structures called pulleys. They're essentially rings around the tendons. And one of these police called the A one pulley can get inflamed where the finger catches and the patients can extend.
Now, in terms of the surface anatomy of these one pulleys, it's essentially ulna to the MCP joint. So, what I simply do is find the MCP joint of the affected digit so you can see the index finger and press right here. And usually, the patients are very tender and sometimes they will catch or sometimes they won't.
Then I'll ask the patient to make a fist and sometimes you can feel that catching. So that's an easy way to determine the trigger finger. The final tendon to examine is the FPL or the flexor policies longest on the thumb. And essentially what I do here is take the thumb and bend it down for me. Strong, good, and relaxed.
This is an important tendon to examine, especially if a patient is at the previous risk of fracture and had a plate that it was placed because sometimes the plates could be proud and the first tendons will be irritated by the tendon of the thumb.
And so if a patient, for example, had previous wrist fracture surgery, had a scar here, what I would do is put my fingers over and ask the patient to bend the thumb. And if I fail Carapetis of that tendon, then immediately I'd be thinking about maybe this tendon is threatened by that plate.
The next thing that we're going to examine is the arteries. So remember, we have the radial artery, and we have the honor artery giving perfusion to the hand. Now, in most patients, they form a complete arch, which means that they're linked. But sometimes you have an incomplete arch whereby the hand blood supply is separated by the two arteries.
So usually what I would do is, first of all, palpate the radial artery, which in most patients you can palpate the honorary is a little bit harder to palpate. And then what I would do is an Allen's test. So what is the balance test?
So, essentially, what I'll do is occlude the arteries and then squeeze your hand as hard as you can. Open and close, keep going and you can see how white her fingers are and just relax. And now with all the fingers out straight now, I'll release the radial artery and you can see how it immediately things up. So that tells me that she has a complete arch to the radial artery, which goes all the way to the other side.
And again, so now I've occluded both. And now I want to look at the overall artery, and I'm looking at the radial digits to see if they pick. So finger straight. And as I relax, you can see how the radial side of digits also picks up so she has a complete arch.
In terms of nerves, the most common nerve to assess on a homicide is the median. And this is the carpal tunnel. This is where a patient, for example, will come in and say that they can't sleep at night. They have to shake their hand to wake it up. Or if they're driving, they have to change hands or the fingers are becoming more clumsy.
THE MEDIAN NERVE
So the median nerve essentially innervates the thumb, the index long ring finger on the radio side of the ring finger, the small finger, and the only side of the small finger is innervated by the ulna. Now, the median nerve gives a motor supply to the abductor pollicis brevis, which is this nice thick muscle in the thumb. So the easiest way to test this is to ask the patient and just touch my thumb, lift it up and you can see I'm testing the strength. Now some patients will cheat. What they will do is that they'll rotate their hand a pronate.
And as a pronated, you think to yourself that they're firing the muscle. So what I'll classically do is hold a hand down and pull supination. The next thing that I'll do is do that Tinel sign where I'm tapping the nerve. So essentially I'm tapping the nerve. And in somebody with a carpal tunnel, they'll complain of tingling in the fingers.
Now, in terms of irritating the nerve and compressing the nerve, you can do the compression test where I simply press on here and see if that causes numbness and tingling or you can do a felon's test. So with the Feagin test, essentially by flexing the wrist, what you're doing is you're putting pressure on that yellow carpal tunnel nerve. And this is why night sweats work, because night splints prevent you from flexing your wrist.
So now if a patient complains of tingling in the thumb index along with the radio bow to the ring finger, that would tell you that the medium is decompressed. We mentioned that the other nerve to examine is also the only nerve that runs along the medial aspect to the forearm, and it runs between the platform and the hook of the Hamate.
So it comes through in this area and usually when patients have numbness and tingling in the ring and small finger, it's invariably at the level of the elbow called the pubertal tunnel. But sometimes it can be compressed in this region. And this is called GILD's Canal. And so what I would do again is elicit the Tinel. And also, I would press on Yield's Canal to see if that causes any numbness or tingling.
Now, one of the ways to determine if the level of compression is either distal or proximal is if patients have normal feeling to the finger on the bat because the dorsal central branch, the ulnar remember, comes off proximally from volar to dorsal. And so if patients have numbness of the back of their fingers, that will tell you that the pathology is actually coming from the elbow and not at Deon's canal.
SURFACE LANDMARKS OF PALMS
And then finally are the surface landmarks of the Palm. Now, in terms of the bones, the majority of the bones can be examined from the back. There's less tissue, there's less structure at the back of the wrist. But on the palm side, there are essentially full bones that you can examine.
The first of them is the piece of foam. So this is the most proximal ulnar aspect here. Now, if you aim a line from your piece of foam aiming to your index finger MCP joint, or if you take your thumb and press your thumb, i.p joint, and press here, that will land onto a bone here called the hook of the Hemming's. And this is a very important bone, for example, in patients who are playing baseball or gofers a short fat and have a sudden onset of pain in this area.
You can get a hook of a hammock fracture. And this is a very important clinical puzzle because if you get standard AP and lateral x-rays, you will miss this diagnosis. On the radio side, the two bones to examine. Here are the trapezius and the tropism. You can feel a trapezius ridge right here.
Hopefully, you found some useful puzzles in how to examine the wrist. There are many structures here. And the critical part of this is having a good understanding of surface anatomy and also the specific tests that we've delineated today.
Remember the acronym of STAND: look at the skin, examine the tendons, examine the arteries, the nerves, and the dynamic tests. Because if you miss those out and you're not sequential in your thought processes, you will misdiagnose.
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