Catch up with our third session of our essential clinical anatomy revision series taught by: Mr Tambe who is a consultant T&O surgeon with specialist interest in shoulder & elbow surgery based in East Midlands covering high yield content
Session 3: Upper Limb Anatomy
Summary
This on-demand teaching session provides you with the comprehensive understanding of the anatomy and physiology of a shoulder. It covers the different structures and joints of the shoulder, the various muscles and tendons that control shoulder movement, and comprehensive scenarios on conditions like impingement syndrome and rotator cuff tears. The session will take a deep dive into how these conditions cause pain and how they can be treated, including arthroscopic repair. This session is highly recommended for healthcare professionals who want to enhance their understanding of shoulder structures and conditions, diagnostic techniques, and potential treatment procedures. It also touches on the nerve supply to the muscles of the rotator cuff and elaborates on how an injury or a cyst can affect these nerves. Get a real-life view on these topics with actual MRI pictures and detailed descriptions. This session is not only beneficial for your understanding but also a great tool to explain these situations to patients.
Description
Learning objectives
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Understand the anatomy of the shoulder joint and its various components including the sternoclavicular joint, acromioclavicular joint, subacromial compartment, and the glenohumeral joint.
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Identify and describe the connection and functional roles of different muscles within the shoulder area such as Trapezius, latissimus, rhomboides, levator, and the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, and subscapularis).
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Understand the role of the rotator cuff in stabilizing the humeral head into the glenoid and in contributing to shoulder movement.
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Recognize various shoulder conditions such as impingement syndrome, rotator cuff issues, calcific tendinopathy, and how they can impact shoulder movement and function.
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Understand the nerve supply to the different muscles of the rotator cuff and the implications of any damage to these nerves.
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Computer generated transcript
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The following transcript was generated automatically from the content and has not been checked or corrected manually.
Can you see that? Yeah, ok. Better cool. Yeah, stop there. So look in the shoulder, then a shoulder is not just one joint, right? There are various compartments to the shoulder and I always kind of look at it as going from the top of the shoulder to the bottom and the back. So at the top, you've got the sternoclavicular joint which is not seen in this picture. But that's the connection of the clavicle to the to the center of the body. And then you have the acromioclavicular joint that you can see at the top. That's where the clavicle connects to the scapula. You've then got the subacromial compartment, which is the compartment of the shoulder underneath the acromion. Acromion is the the extension of the of the spine of the scapula. And then you've got the actual joint, the glenohumeral joint, which is the joint between the ball and the socket. And most importantly, people forget this. But the other part of the shoulder joint is the joint between the scapula and the thorax. The scapulothoracic joint where a lot of shoulder movement will occur. Next, please remember there are five muscles that connect the upper limb to the vertebral column. Uh I'm not gonna start naming each of these. There are four muscles that connect the upper limb to the thoracic wall. So like the, the serratus, for example, and there are six muscles that act directly on the shoulder joint. Next one, there you go, you see each of them here. So you've got the Trapezius, latissimus, rhomboides and levator, which are connecting the upper limb to the vertebral column. Then you've got the pectoral subclavius serratus which connect the limb to the thoracic wall. And then most importantly, I think for relevance today, it's the the rotator cuff muscles, the there is major and the deltoid and I assume you all know what makes up the rotator cuff. It's the supraspinatus infraspinatus, there is minor and subscapularis. So next one and pull up the next one. So if you compare the shoulder and press one more uh Ellen. So there are two compartments. It's like a double decker bus. The glenohumeral joint is the lower compartment and click again, you've got the upper compartment, which is the subacromial compartment. And there are things that are quite unique to each compartment. And that is why I like to compartmentalize these two things. What separates the two compartments is the rotator cuff. The rotator cuff is the barrier between the subacromial space which contains the bursa and the rotator cuff will then divide the bursa and the space from the underlying shoulder joint, which is where you've got various structures which we will come to in a second. So, next one, so here's what you start seeing inside the shoulder. Ok? You've got the four muscles that make up the rotator cuff from front to back. It is the subscapularis, which is an internal rotator. You've got the supraspinatus which abducts the arm infraspinatus and teres minor, they rotate the hand externally and inside that you've got a whole host of ligaments which connect the glenoid and the humeral head. And again, we'll talk about the relevance of this in a second. Next one. And that's the bursa which sits in the subacromial space. You see how the bursa is a pad between the acromion and the rotator cuff tendon and inflammation in this bursa creates a condition called bursitis. It also contributes to a condition called the impingement type pain, which is when you're lifting the arm laterally. The bursa gets pinched between the acromion and the humeral head and that creates a painful condition called the impingement syndrome. Next one up. So here's the rotator cuff again, showing you the various elements of the rotator cuff. Remember, the muscular part is medial and the muscle bellies all coa into a single tendon which becomes like a big hood that covers the, the shoulder of the humeral head and inserts on the graded tubs and this insertion is then called the rotator cuff tendon. Ok. Next one up. Yeah. Keep going. Take a cuff are the most important muscles within our should. No, no, you can and, oh, sorry, you can go to the next one. Take a cuff. OK. So I can put the volume off because I think this was something I recorded previously. Oh, I'm not quite sure what to do that. Uh It's also an awful rotational movement. Sub Alaris is an internal rotator and I could see what it's saying anyway. So, OK, what does the rotator cuff do? Ok. He and leave it, we'll just go through it and go back. So the rotator cuff is not only a muscle and tendon that helps to lift the arm and move your shoulder joint. The main function of the rotator cuff is to stabilize the humeral head into the glenoid. So when the rotator cuff, which is a hood, it contracts, it brings the humeral head and centers it on the glenoid. And then of course, it does the various movement, especially the external rotation movement. It does not abduct the shoulder on its own. It requires the help of the deltoid muscle to complete the full range of movement. So the rotator cuff working in tandem with the deltoid will result in the full range of shoulder movement on its own. It can't do much next one up. And this is what I was uh talking about the impingement syndrome. You can see how there is a tight space above the rotator cuff, but underneath the acromion where you have the bursa, if there is a degenerative condition that involves the bursa, um that will then cause inflammation of the bursa and the underlying rotator cuff that will then result in a inflammatory and painful condition when lifting the arm outwards and forwards. And this is of course called the impingement syndrome. Someone said, can you click hide icon on the screen? I can't do that. Ellen, maybe you can, I don't know. What was that for? Is that OK? Ok. It's done. OK. Next slide. So some other conditions that can cause a problem with the rotator cuff on the left side, you've got that flashing green sign. Now that is a spur of bone that can grow from the acromion, that spur of bone can be seen very nicely sometimes on x-rays. It can be seen also during arthroscopy and what the spur of bone does is it catches on the tendon, the rotator cuff tendon underneath. So you can imagine someone trying to lift their arm up. That big spur of bone is going to dig into the rotator cuff tendon. It may contribute to a tear of the rotator cuff tendon or it might even produce persistent impingement symptoms. The other pathology that can sometimes inflict the rotator cuff is this calcific tendinopathy. You see that word of calcium sitting in the tendon in the subacromial space that's almost like a like a blob of gritty paste like calcium that produces pain by causing pressure within the cuff rotator cuff. And it can also produce pain, inducing chemicals. It is one of the most excruciatingly painful condition in the shoulder. So these are the two common rotator cuff issues, impingement, calcific tendinopathy that will produce a lot of pain. Next slide, what will also produce pain? A and is related to the rotator cuff is a rotator cuff tear. Now, if you see this slide, you're looking at someone's shoulder from the back, the right shoulder, you can see the spine of the scapula and the spine of the scapula is now laterally as you go laterally, it curves around into the acromion and you can see that the supraspinous and the infraspinous fossa are quite wasted. And what does that mean? That means that the muscles, the supraspinatus, which is above the spine and the infraspinatus muscle, which is underneath the spine of the scapula, they are wasted very likely because of a chronic rotator cuff tear. When the rotator cuff tears, these two muscles are now disconnected from their insertion and this results in wasting and atrophy of those two muscles. So, next slide. Now, so in this picture on the left, you can see a tear of the supraspinatus tendon on the right side. This is how that tear will look when you are looking at it with an arthroscope. So you can see the humeral head on the right hand side and with an instrument, I'm lifting up the torn rotator cuff tear. So now a rotator cuff tear will result in communication between the subacromial space and the inside of the joint. So when you've got a big tear, the two spaces become one, the two compartments become one. So the do double decker bus, imagine that part of the floor is gone. You can see from top to bottom. This is what happens when there is a big rotator cuff tear. What can you do? You can do a arthroscopic repair of the rotator cuff. Next slide. So you can clean it up, you can put little anchors in the bone and you can repair the tendon securely down to the greater tubos. This greater turo part is called the footprint of the rotator cuff. And you can repair it using various arthroscopic or even open surgical techniques. And this is one of the most common arthroscopic surgical procedures that we now do. So. Next one, then, so what supplies the, the the muscles of the rotator cuff? And when I talk about muscles, the subscapularis is supplied by the subscapular nerve. The supraspinatus is supplied by the suprascapular nerve. OK. The suprascapular nerve is a very small stubby nerve that comes off quite proximately in the brachial plexus. That nerve is originating from the C 56. It passes through a little notch called the suprascapular notch on the scapula and then it swings around the spinoglenoid notch. That's the notch that you see at the bottom. So it's swinging around with the artery and as it swings around, it is supplying nerve fibers to the supraspinatus muscle belly, which is above the spine and the infraspinatus muscle belly, which is below the spine. So imagine if there is anything that affects the nerve in the notch, it will cause also pathology of the muscles because the nerve will be knocked off. So I'll tell you how that happens. Next, slide, next slide. So yeah, any traction injury just go back one slide, traction injury to the nerve that can sometimes happen during an injury, brachial plexus injuries, typically, if the brachial plexus injury is quite proximal, that will take off the suprascapular nerve. So proximal brachial plexus injuries, you will find that the suprascapular muscles have been defunction. If there are any cysts or a tight ligament or a hypertrophied ligament, again, it will knock off the nerve. Um and sometimes instruments and arthroscopic surgery can cause injury to the suprascapular nerve. Next one, you can see again how the infraspinatus is quite wasted. And uh typically, uh uh isolated infraspinatus wasting can happen when there is a cyst that occupies the spinoglenoid notch, which is where the nerve is curving around underneath the spine of the scapula. If there is a cyst in that area, it will spare the supraspinatus, but it will catch the infraspinatus. Next one. See there as the nerve is swinging around. I've shown an MRI picture of the cyst that cyst is sit is sitting at the back of the shoulder joint that will compress the suprascapular nerve as it comes around the spine and that will typically compress and defunction the infraspinatus muscle that results in a deficit of external rotation. Ok. Next one. Yeah. Next slide. Ok. So what is this? We are coming off from the rotator cuff to something different? Does this look normal or abnormal? Looks abnormal? Right? That doesn't look like the the the normal shoulder? That's a acromioclavicular joint, but the clavicle is sitting quite high in relation to the rest of the shoulder joint. So what's happened here? Next slide. There you go. That's what's happened. You can see that the clavicle is sitting very high in comparison to the acromion. That's because this chap came off a bike landed straight on the point of the sho shoulder and that resulted in a disruption of the acromioclavicular joint. So how does that happen? You've got ligaments that connect the clavicle to the acromion. These are called as acromioclavicular ligaments. You can see them in the, in the picture next to it. But more importantly, there are ligaments called the coracoclavicular ligament that connect the lateral clavicle to the cor uh to the to the coracoid. And these ligaments are the coronoid and the trapezoid ligaments. They are two fanshaped ligaments. You can see them coming off the coracoid there. So, in a severe injury, the coracoclavicular ligaments are disrupted and the acromioclavicular ligaments are disrupted and the clavicle now comes to sit underneath the skin. This is quite a severe injury and it requires then a repair and how can you repair it? You have to reconstitute the distance between the coracoid and the clavicle. And we do that by using artificial ligament that pulls the clavicle down near the coracoid. And you can see how that cor the, the ligament loops around the coracoid and then we fix it down on the clavicle. So that's a coracoclavicular ligament reconstruction. OK. Next one. So what happens in the inside of the shoulder joint? Ellen, keep clicking one by one. OK. So the biceps tendon where it sits on the top of the glenoid that's called the biceps anchor. And then you've got this big fat noodle that's coming out of the shoulder joint. That's the longer of the biceps tendon. This is one of the unique tendons in the body, the long head of the biceps that is intraarticular. OK. There is only one, another tendon in the body that is intraarticular. Anyone have a think you can put a little comment. If you, if you come up with what other tendon is intraarticular, then you've got this big ball of the shoulder joint, that's the humeral head. And then you've got the glenoid. You can immediately see the mismatch between the huge humeral head and the very tiny glenoid, which is a contrast to say the hip joint where you've got a big socket in the hip and a big uh uh a femoral head, but the shoulder joint is completely opposite, which is why it is more vulnerable to instability. You see more shoulder dislocations, but you hardly ever see a hip dislocation. That's because of this mismatch. Ok. Now, around the glenoid, you've got this wall of tissue like a ring of tissue that's called the glenoid labrum. And what it does is it creates a, a depth to the glenoid. And by increasing the depth of the glenoid, it allows the humeral head to be a little more secure. But don't forget there are some ligaments which will connect the glenoid to the humeral head. And all these ligaments become part of that labrum. So you've got various ligaments called the superior middle and the inferior glenohumeral ligaments. And each of the ligament is part of the, the condensation of the capsule. And we will look at this when we come to some of the shoulder instability problems. So, next slide, OK. That's the rotator cuff, keep clicking and that gap at the bottom. Ok. So instability typically seen during accidents but mainly also during sporting injuries when someone lands on a hyper abducted arm or when there is a a sudden force that pushes the shoulder out. There are two types of dislocations by instability. I mean a dislocation of the joint, the joint can dislocate anteriorly and inferiorly or it can dislocate posteriorly anterior dislocations are more common. 98%. Posterior posterior are quite rare when someone dislocates the shoulder, you get this squaring of effect. Compare this chap's dislocated shoulder with the opposite side. The opposite side is nice surrounded, but on the dislocated side, it's almost like a squaring of effect which is very typically seen in the dislocation next one. So this is a dislocated shoulder. You always need two views, never make a diagnosis On a single view. Always get two views to decide which side the joint is dislocated. But common things being common, anterior is more common. Next one. And here's another view. So when someone dislocates a shoulder, we are looking at the on face view of the glenoid, they will disrupt this labrum typically in the front. And when this disrupts in the front, that lesion of the labrum is called a Bangkok lesion, you can see a arthroscopic view. You can see how the labrum has pulled off from the glenoid. But I've also added a CT scan of the glenoid. This is a on face view of the glenoid. Sometimes, not only will the labrum strip off, but it will also take off a little flake of bone with it. You can see a little flake of bone on the on the CT scan. And when that happens, that's called a bony bank card. Ok. So make a distinction. You've got the soft tissue, a pure soft tissue injury. That's a soft tissue bank card. But when the bone chips, it's called a bony bank card. And immediately you can see that by having a bony bout what has happened is you've lost the surface area of the glenoid. The glenoid already is a small bit of bone. It's like a little coin. And when you chip some bone on it, you've now got even less bone for the humeral head to balance on next one. So imagine the glenoid is like the tea that's sitting the golf ball on top of it. As long as we've got a tea that is uh complete, the ball can barely balance on top of it. But the minute you lose bone or you lose the soft tissues that stabilize the humeral head to the glenoid, the ball is gonna fall off. Ok? Next slide. Ok? I'll just briefly touch upon the ligaments again. What you see here is the capsule, which is in that uh kind of blue color, but the white condensations are the middle and the inferior glenohumeral ligaments. Now, the inferior ligaments, the anterior and the posterior inferior glenohumeral ligament. They are very important. I'll show you how next slide keep going. So you see those two ligaments, they create a hammock for the humeral head, ok? The anterior and the posterior inferior glenohumeral ligament. So you see the humeral head sits happily in that hammock as long as things are all going well. But the minute there is an injury and next one that hammock is disrupted and you can see how the humeral head will easily fall off. Ok. So those two ligaments are very important to maintain stability of the joint. Two ligaments, the anterior inferior gleno humeral ligament and the posterior inferior glenohumeral ligament and the capsule in between that creates the hammock. Ok. Next slide, what can you do if there is an injury to the labrum, you can repair it with a keyhole arthroscopic technique. So we put little sutures to repair the labrum back. So this is how it looks. When you're looking with the camera in the joint, you can see a repaired labrum. You can see how nicely we have created like a bumper effect. It's almost like a, a water of tissue. Now that is gonna stop the humeral head from roll, rolling out. Uh next one. But what happens when you've lost bone on the glenoid? Remember we talked about the bony bank card when you've lost bone. Normally the glenoid should look like a, it should look like a pear, it's pear shaped. But when you lose bone, it is typically called an inverted pear. When there is bone loss, you can't just do an arthroscopic repair of the labrum. Sometimes there is no labrum to repair. In that case, we do a boning procedure. Next one, this procedure is called a latter procedure. So what we do is we take off the coracoid, we turn the coracoid around, put it around the face of the glenoid and fix it there with a couple of screws. Next. Next click, see that the coracoid is now fixed to the front of the glenoid. So we are almost trying to extend that area of glenoid that has been lost due to bony injury. And this procedure was popularized by a French surgeon called Michel LA. And that's become very popular. Ok. All high end athletes contact athletes, collision sport where there has been loss of bone on the glenoid. We have moved away from trying to do an arthroscopic repair and we now do this procedure called the LA. OK? There's a question when you're repairing the labrum, does the humeral head need to be dislocated from the joint during the procedure? No, we don't need to dislocate the joint is wobbly. We know it is wobbly because the labrum is damaged. But once a shoulder has been relocated, generally, it will sit there until the next episode of dislocation happens. But we can easily un put a camera in the joint, we put some fluid to distend the joint and then we will put some more instruments and then uh then prepare the labrum for a repair and we use little little suture anchors to then repair the labrum back. OK. So the, the humeral head does not need to be dislocated during the procedure. Next one. OK. What do you guys think is happening here? This is someone both shoulders and profile right shoulder and left shoulder is something going on. Here is something abnormal. Well, I'll tell you what's happening. The left shoulder looks quite wasted, doesn't it? There is a chunk of muscle that is completely wasted away. Absolutely muscle wasting of deltoid. Matthew is on the roll, well done. Matthew, it is deltoid wasting. And why has that happened? Why may de why may deltoid waste away like that next slide? Because something's happened to the axillary nerve. The axillary nerve is the main and only nerve that brings motor supply to the deltoid. And why am I talking about the axillary nerve? Because the nerve sits in the axilla very close to the humeral head and the inferior capsule. So when someone dislocates their shoulder anteriorly, there is a risk of injury to the axillary nerve. Next slide. See there, the axillary nerve comes around through that interval right underneath uh the, the humeral head. Next slide. The next thing, yeah, it is is derived from C 56. It supplies the deltoid and the teres minor and it is prone to injury. When there are fractures of the humeral head, surgical neck. It can also be damaged when someone's using a crutch for a long time, it can be damaged when there is a dislocation. And hence, when you guys go and see someone with a dislocation, the first thing you need to check after you've done various other checks is to document if that axillary nerve is working. How do you do that? You ask for sensations in the regimental badge area, which is this patch of skin on the lateral arm. That is the only sensory area for the axillary nerve. And once you have relocated the joint, you can ask them to gently push their elbow on your hand and feel for the deltoid contraction. If the deltoid is contracting, the nerve is working. Ok. Next slide, there you go. That's the regimental badge area. And that's again, someone with deltoid atrophy. When the axillary nerve is damaged, deltoid will, will atrophy very quickly. And it's an absolute nightmare when someone's lost their deltoid because they lose their shoulder function quite badly and it it it doesn't come back easily. Next slide, this is another case, see a very severe fracture of the proximal humerus. The humeral head is dislocated and fractured. You know, injuries like this put the axillary nerve at a high risk of um uh of damage. They can also sometimes damage the blood vessels in that area. The axillary vessels can get damaged. So when you see someone like this, not only do you test the brachial plexus and the axillary nerve, you also look for perfusion in the hand, make sure that they've got a good radial pulse, make sure that the hand is warm and there is a good capillary refill. Ok. Next slide again, a displaced proximal humeral fracture, but you will see that there is a little sharp spike on the humeral shaft media. Now, that can be a problem. I'll show you how next slide see this is the blood supply to the proximal humerus. The blood supply comes from the anterior and posterior circumflex vessels that loop around the neck of the humerus just underneath the humeral head. And then ascending branches go from this little li little anastomosis and these ascending vessels will supply the humeral head. Now, what happens when there is a a dislocation or more importantly, when there is a fracture of the humeral head, just like the one you've seen, these vessels can get damaged, they can get completely disrupted and just like the femoral head. When there is disruption of these vessels, you can have avascular necrosis of the humeral head. Ok. AVN can happen in the femoral head. It can very similarly happen in the humeral head. Next slide. So this is what it looks like. Then you've got the little Diagrammatic that shows the nor normal vasculature. But in the AVN, the blood supply to the humeral head is disrupted and the segment where the blood supply is disrupted will now collapse, the articular cartilage over that segment will collapse and this will lead to arthritis. Ok. Again, it's a nightmare to treat this. And more often than not these patients end up requiring a shoulder replacement. So that is AVN, you're looking at the X ray of the V of AVN, ok. Uh while we are in the area of the axilla, I think you guys, all of you need to know all these spaces, you know, the triangular and quadrangular spaces. They often come up in various exams and examiners are absolutely fond of asking you about these triangles and rectangles. OK. Next uh next click Ellen. So these are the spaces I'm not gonna go into detail but have a read up the quadrangular space, the triangular, upper and lower triangular spaces and make sure you know the boundaries of these quadrangles and triangles. OK. Not only the the boundaries, you also need to know what runs through these spaces. So, next slide. So these are the the the two triangular and quadrangular spaces, but there are blood vessels and nerves that run through each of these. Next click. Next click, no, come back. So there in the quadri in the quadrangular or the quadrilateral space, you've got the axillary nerve and the posterior circumflex humeral artery. In the triangular space between the Teres major and Teres minor, you've got the scapular circumflex vessels and in the lower triangle, you've got the radial nerve and the profunda brachial artery which goes with the radial nerve and travel, travels across underneath the triceps. We will look at it when we talk about humeral fractures. Ok? Ok. Take a second. Give me a heads up or a thumbs up if we are going at OK. Space. And if this is what you want to listen or if you want me to change Tack Ellen? Is this correct? Is this perfect? Thank you. Yeah. Anyone else Francis? Are we going? Ok. Are you absorbing things? Absorbing things? Matthew, I think Matthew is the only one listening? Great. Excellent. Ok, good. So what are we looking at now? Is this a tumor on the shoulder, on the back of the shoulder looks horrendous. No, it's not a tumor. It's someone who's got a horrible scapular winging. Yeah, scapular winging, massive winging. And why might someone wing their scapula like that? What causes winging? Next? Slide? It's a problem with the long thoracic nerve. That's the most common thing that will cause ringing. The long thoracic nerve click again, travels down the chest wall. It comes off the brachial plexus quite proximately. It's, it's a long, thin, slender nerve, very prone to injury and it goes down along the chest wall and it supplies the serratus anterior muscle, which is a big muscle that connects the rib cage to the scapula. And if that muscle is paralyzed because of a long thoracic problem, long thoracic nerve problem, then the minute someone tries to lift their arm up, the entire scapula will lift off. Ok. And that is scapular winging, you can get scapular winging. Also, if someone has got a Trapezius, palsy, trapezius muscle problem, which is because of a spinal accessory nerve palsy, or if someone has a longstanding rotator cuff, then the entire dynamics of how the scapulothoracic movements happen is disrupted. So the scapula is now being randomly pulled by the other muscles around the scapula that are trying hard to compensate for a long term painful problem. And that can also cause some mild winging of the scapula. Ok. So remember it's not just the long thoracic nerve and serratus anterior that will result in winging, it can also be just a kind of loss of conditioning around the shoulder or it can be the the trapezius that can result in winging. OK. Next slide. So uh this is a few details about the long thoracic nerve. I'll let you guys read this for a couple of seconds. Move on please. And yeah, paralysis of serratus due to long thoracic will result in winging as you can see here. Next slide. OK. Moving on from Serratus do something in the arm. What's going on here? I've actually given you a clue by putting a picture next to it. Little cartoon, I guess biceps rupture, correct. So that's the classic Popeye. OK. Popeye biceps. Now then remember biceps muscle is connected proximally and distally by long tendons. OK. Next slide, what you're looking at here, that clinical picture you just saw was a Popeye because of a rupture of the long head of the biceps, which is the proximal part of the biceps. OK. So approximately you've got the long head of biceps and the short head of biceps, the long head of the biceps is this long fat noodle that starts from inside the joint, the supraglenoid tubercle and then it comes out from the joint between the supraspinatus and subcapillaris tendons. And then it comes outside the joint going in the intertubercular sulcus. You can see that in that picture where it is held by the intertubercular ligament which creates uh uh like uh it's, it creates a tunnel for the tendon to pass through. So the bicep muscle essentially has the long head and the short head. What ruptures most often is the long head? And why does it rupture because it is prone to degeneration. That tendon also has a zone of poor blood supply. And with ongoing degenerative change in the tendon, it can undergo mucinoid degeneration and sometimes just lifting something innocuous, the tendon will pop, the patient will come and tell you I was maybe lifting a box and something just went pop. I had a twinge of pain and then the pain has settled. But my arm has come out with this weird Popeye for some people. It creates no problem whatsoever. And generally 99% of the time we will treat this non surgically, we just have to tell people to get on with it. But we assure them that apart from the cosmetic Popeye, it is not going to stop them from doing their job or doing what they need to do day to day. However, I also typically see a lot of people who are kind of doing gym work and imagine someone's in a gym. They've got a big bulging bicep, uh Popeye in one side and on the other side it's, it's a nice bicep that they've been building over years. And th this, this typical category gets very fixated on the cosmetic appearance of the bicep. Ok. And some of them will keep hounding you until you do something about it. Can you do something about it? Yes, you can, you can trim the biceps, the longer biceps tendon and you fix that biceps tendon into the humeral shaft with some suture anchors. This procedure is called tenodesis. But you need to tell those people that whatever you do, they will not get a normal biceps contoured how much they work on it. There is always gonna be some asymmetry between the two biceps. OK. So they need counseling because they expect quite a lot from this operation. Thinking now they're gonna have a biceps that's going to look absolutely equal to their opposite side. Doesn't always happen. OK. So this is the long head biceps rupture that creates a Popeye next sign, next line. Well, hang on. There is another Popeye here, but you will see how the biceps is now moved proximately. OK? And there is a lot of bruising distally. Why has that happened? That's happened because the distal biceps tendon has ruptured. Now, the distal biceps tendon ruptures generally because of something traumatic and usually that's when someone's been doing a heavy job and something gives like something slipped from their hand and they were trying to catch it. And there's this sudden force on the distal biceps tendon and the distal biceps tendon then ruptures. What does the normal biceps tendon look like distally? Well, distally, the biceps tendon inserts on the tubos of the, the radius, the radial tubos. So part of it swings around to the radial tubos, but the rest of it is called the, the lacertus fibrosis. The lacertus swings medially and covers the, the common flexor. But when there is a rupture, it's actually the tendon that's come off completely from the radial tubos. These people can get a lot of pain. They also get cramping of the biceps when pronating and supinating the forearm and they actually lose some strength. And typically these are young people doing heavy jobs and the tendency is to repair this back to the radial tuberosity with some suture anchors. Ok. Now, what is the preliminary or the main function of the biceps most often, you will think that the main function is flexion of the elbow. If you think it is flexion, it is incorrect. The main function of the biceps is supination. Biceps is a prime supinator, the muscle underneath it, the brachialis is the prime flexor. So someone who has a distal biceps injury, they don't lose a lot of flexion strength. What they lose is the ability to rotate the forearm, they lose supination and pronation strength. So if you've got someone who's uh electrician or a plumber where they have to constantly rotate their forearm. They are, you know, doing manual work, putting in screws, tightening screws, typically they get a lot of weakness uh um in pronation and supination. So you need to counsel these people correctly and you need to tell them, well, look, you're not going to lose your flexion strength. It's your supination strength. That's gonna be the problem. OK. So remember this distinction between approximal biceps tendon, which is generally treated non surgically versus a distal biceps tendon. Both of them create a Popeye, but a different type of a Popeye. When it's the distal biceps tendon, the tendency is to repair, not repair for everyone. You have to, to select your the the patients. It's generally the people who are working, doing manual jobs. That's where you repair them. Next slide. What's happened to this chap? Why is he holding his hand like this? What you're looking at guys is someone who is unable to extend their fingers at their MTP joint? OK. And when you start thinking of this deformity of the fingers in relation to what we have just discussed, which is distal biceps tendon, rupture and surgery in that area of the elbow. Is there something in that area that you can prank and create this deformity? There certainly is. Next click, the posterior interosseous nerve, the pin OK. Dude, it's not the ulnar nerve, it's the pin, posterior interosseous nerve. This is a branch of the radial nerve. OK. And uh pin, as you can see in the picture travels very close to the biceps and it is very close to the insertion of the biceps on the radial tubos. So when we are doing a repair of the distal biceps and working quite close to that area, the posterior intraosseous nerve, which has again, two divisions, the superficial division and the deep division. And you will see the various muscles that it innervates, it innervates the extensors of the forearm. Uh injury to the P I will result in weakness of extension at the metacarpophalangeal joint. It will not result in a wrist drop. Why? Because the wrist extensors are supplied by the radial nerve much approximately. So if you've got someone with a wrist drop, the problem is with the radial nerve. If you've got someone with reasonable wrist extension, but poor extension of their digits, then that is a pin or posterior intraosseous nerve injury. And that can happen surgically because of the surgery. I've just explained it to you. That's one of the common kind of uh injury, uh uh zones, but also next click. Oh That's again another picture showing the, the course of the radial nerve and how it branches into the posterior intraosseous nerve. You can see how close it is to the dis to the proximal radius. And this posterior intraosseous nerve will pierce the supinator muscle right at the top. And that's where it's quite a tethered and prone to injury. Next click, please. Ellen. This is a another injury which we often see and this injury is called the Montia fracture dislocation of the elbow. You will see that there is a fracture of the proximal ulnar with a dislocation of the radial head. Ok. When the radial head dislocates with force, it can prank the posterior intraosseous nerve. And it can again result in a extension deficit at the metacarpophalangeal joint. Ok. So it can be a fracture or it can be something surgical that can result in pi and injury. So someone who's had this elbow injury or someone who's had elbow surgery, always check their radial nerve function, always check their pin function. What did we do to this fracture? We plated the ulnar. Once you plate the ulnar and you align the ulnar and make it straight, the radial head pins back very nicely. You don't need to operate on the radial head, the radial head will become stable once you have corrected the ulnar. Ok. This injury is the montage fracture dislocation. All right. Next slide. And what's happening here? This is a very common location for a humerus fracture. This is the humerus shaft. It's fractured at the middle third, distal one third kind of junction and that spike of bone that you're seeing there. Yeah, spinal fracture is correct, but this fracture is very prone in causing an injury to another nerve. Any idea which nerve goes around that area? It's the radial nerve. OK. Click up, please, Ellen. So this is another fraction configuration. Uh click again. So you see the radial nerve comes on the back of the humerus. It runs in the spiral groove at the back of the humerus, descending from medial to lateral where it is in the spiral groove. It is very closely attached or related to the bone. And then it swings around on the lateral side and on the lateral side, it is tethered to the humerus by the lateral intermuscular septum. Now, this septum there is no give in the septum. So when there is a fracture, the nerve is tethered to bone by the septum. So it cannot move. But the bony fragments are not mobile and the movement of the bony fragments with a relatively tethered radial nerve results in radial nerve injury. Ok. Everyone who has a humeral shaft fracture, you have got to be absolutely 100% documenting their radial nerve function. So I've got a couple of operative pictures. You can see the, the humeral shaft that I've caught, I'm, I'm holding the radial uh the the humeral shaft in uh in like a bone holding clamp. But you can see how the radial nerve is crossing it. Yeah, very closely applied and the fracture is right underneath it. But further down the radial nerve runs parallel to the lateral part of the, of the distal humerus. And that's another zone where it can be injured. So, radial nerve is a very sensitive nerve and very easily prone to injury. And hence, you've got to document the function of the radial nerve. If there is a deficit in the radial nerve, you will see a wrist drop. Ok. Next slide or next click. So this fracture, this is what we did. We fixed it with a long plate. When you're putting a long plate like this, you've got again to be careful of that radial nerve, which is that little yellow line I've put there because what you don't want to do is to trap the radial nerve underneath the plate. It has happened. It's very easily done. If you don't carefully look for the radial nerve dissect it out of the way, there have been medical negligence cases where the surgeon has put a plate. Then there is a radial nerve palsy. That's either because the nerve has been handled roughly during surgery or the nerve is trapped underneath the plate. And if you have squashed it underneath the plate, the nerve is dead, it is not gonna wake up. It is going to need tendon transfer surgery or major nerve repair surgery. Ok. So be very, very careful if you're around the radial nerve. And as a junior doctor, you might be assisting someone who's doing a uh an operation on the humerus and you might be holding a retractor in your hand. If you are close to the radial nerve, do not retract, forcefully, forceful, retraction will cause traction injury to the radial nerve. You gotta be very, very careful. Ok. Next slide and again, these are some uh locations where the radial nerve can be visualized, but I think we have talked about it already. So next one um and I've just said um if there is a radial nerve injury along with the humeral shaft fracture, most of them will resolve on its own, meaning that it is a neuropraxia. But of course, then there can be higher grades of injury, sis and neurotmesis recovery can be seen by eight weeks, but sometimes the nerve can continue to recover, taking up to a year to recover. Um And this is more surgical, I think I'm gonna skip the more surgical aspects. Next one next slide. Now, then this is another bad fracture. Ok. A completely busted distal humerus fracture involving the elbow joint. Ok. The elbow joint is now fractured, meaning it is an intraarticular fracture. You can see the middle picture is a traction film showing the extent of the injury. And then you've got some pictures during surgery, there are so many fragments that you've got to hold all those fragments with little K wires. Ok? Little wires that hold the fragments together and it's almost like putting a jigsaw together and then you see a yellow tape you see that little yellow tape around the structure. What nerve might be in that area that tape is protecting something that tape guys is protecting the ulnar nerve, which is very, very, yeah, correct Matthew that is very close to the fractures, two nerves which are uh potentially very close to these fractures of the elbow, mainly the ulnar nerve, but also the median nerve. Ulnar nerve is quite superficial. You can feel it on the medial aspect of your elbow. You cannot palpate the ulnar nerve next slide. So there's the ulnar nerve. Um You can see the yellow sling, it sits on the medial aspect of the tricep. You shouldn't be pulling on that uh on that uh little elastic cord. Uh again, pulling on that cord may cause ulnar nerve injury. The ulnar nerve travels on the back of the elbow, very superficial going around the cubital tunnel, which is behind the medial epicondyle, which is why if you hit your medial part of the elbow, um say if you knock it on the table, you suddenly get this sharp, shocklike sensation like uh uh electric shock sensation going down the hand. That's why it's also called the funny bone that, that part of the, the electron and the ulnar nerve then goes deep as it starts going below the elbow. It goes between the two heads of the flexor carpi ulnaris, that red line there. So that's where it disappears deep. And once it goes once it has gone into the FCU, then it's less prone to injury. But most of the injuries happen very close to that medial epi candy. Next slide. Yeah, injury around shoulder is not common but around the the elbow is more common. Next slide. So this just shows you the the sensory areas of the ulnar nerve. The ulnar 1.5 digits is the ulnar nerve and the radial 3.5 is the median nerve. How do you do a motor test where you're testing for intrinsic muscles? Next slide. So the ulnar nerve supplies the all the intrinsic muscles of the hand. It supplies the hypothenar muscles in the hand and it also supplies two or three long deep muscles in the forearm. Now, this is something you might want to look up. This is called the ulnar paradox. Ok. The more proximal the injury in the ulnar nerve, the less the deformity in the hand. Ok. If there is a ulnar injury or ulnar nerve injury, it results in a ulnar clot. This is called clawing of the, of the, of the fingers. But if the nerve injury is quite distal, it results in a more severe clot compared to the proximal level. And that is because when the lesion is higher, the long flexors to these fingers are also paralyzed, meaning you don't have the long flexors pulling them into a a clock. Ok. So this is an interesting phenomenon. This is called the ulnar paradox. Read it up because there it's quite a bit of explanation, but I just wanted to highlight this to you. So you clearly understand that uh lower ulnar nerve injury results paradoxically in a more prominent deformity than a proximal nerve injury. Ok. That's counterintuitive because you would think the more proximal the injury, it should be more bad, but no, it looks less bad if the injury is more proximal next slide. And that's the fracture, the fracture you saw the completely busted joint. This is what we did, put plates and screws and it's like a jigsaw guys. You've gotta put it together and then can you guarantee full movements? Well, if not really, once you shatter the elbow to the extent that this guy had, you can put it back, but you can't really guarantee full function. They generally are left with some deficit in their movement. Next slide, median nerve root values, it supplies the thinner eminence and the, the, the movement of the thumb across the fingers is what the median nerve does. It also supplies flexor muscles in the forearm. Next slide. So it's again, not commonly injured, but it may be injured around the wrist area when someone, um gets a bad injury around the wrist like uh uh a stab injury or uh a glass, someone slashed their wrist with a glass or whatever. That's when you get a bad um uh median nerve injuries. Next slide, we have seen this the sensory distribution of the median nerve relative to the ulnar nerve. What's the best way to test the, the motor part of the median nerve when you look for the, the thinner eminence, and you look for action of the abductal poly brevis that is ability to lift the thumb out of the palm upwards in this fashion. Ok, not laterally but upwards. See that you should see the thinner muscles activate. So that's the median nerve next one. So median nerve can also be injured in high. Uh uh there can be a high injury and if there is a high injury, then you look for flexion of the wrist. The ulnar nerve supplies the flexor carpi radialis. That's a big forearm muscle that flexes the wrist. So you're looking for wrist flexion and ability to pronate the the the the arm. Next one. Ok. Look guys, there's a lot of other traumatic things that are the more common situations, but there are things and situations in the upper limb when you need to worry about and seek advice. If you look at a big swollen joint, it's red, likely infected but could also be something like a tumor, you know. So tumor pathological fractures, nasty fracture, dislocations, infections and vascular injuries to the hand. All these things are bad things. When they happen in the upper limb, you risk losing part of the arm or the entire arm. If these are not picked up in time. Ok. So be careful in documenting and assessing neurological and vascular status. Um If there is a bad injury, if there is a swelling that looks abnormal, there are dilated veins, something looks red, angry, thick tumor, think infection. Ok. Next slide, I just wanted to quickly touch upon um shoulder x rays. OK? When someone is being sent for an X ray, just doing a single view is of no use. There are various views that we commonly do in the shoulder. But the most common view is uh AP and Axillary review. So that's uh picture A and picture FF is a review and A is the AP view. Uh Some other views are uh also uh also done. Uh the, the picture E is also a nice axillary view. It's taken from above to bottom and you can see the humeral head and profile. You can see the glenoid in profile. You can see the coracoid which is the hook in the front picture. D is what is called an outlet view. OK. You can see the, the humeral head outlined on the spine of the scapula. It's called the Mercedes Benz of the scapula and the humeral head is uh is superimposed on it. So, remember two views for shoulder injuries, um and most conditions in the shoulder. Next slide. What are the other common investigations when we are looking at shoulder conditions? We use a lot of ultrasound scanning. Ok. Ultrasound is a good dynamic assessment of the shoulder. It gives you a good assessment of the rotator cuff tendon. It will show you subacromial fluid. It will also show if there is calcium in the rotator cuff, it will tell you if there is a rotator cuff tear. It will tell you the nature of the tear. Is it a full thickness tear or a partial thickness tear? It will give you the dimensions of the tear. How big is it? But it is quite operator dependent. Sorry, my dog is snoring. Better stop snoring. It is also quite operator dependent. Ok. You need a good ology consultant or a technician who can do a good scan and interpret that scan. OK. We also routinely do a lot of shoulder injections using ultrasound scan. Next slide Ellen, next to it. We've got the MRI scan. Do you know? I see a uh I'm increasingly seeing a lot of MRI scans being organized in primary care for things that we don't really need an MRI scan for. Ok. If there is a rotator cuff problem, I would rather I see them with the X ray. Yeah, that's good if you organize the X ray, but a lot of these things can be sorted with the ultrasound scan. MRI is an expensive investigation. It is a time consuming investigation and it is not a comfortable investigation for the patient. They have to position the arm in a certain manner and they have to stay in the MRI tube for up to 40 minutes, people get claustrophobic and they find it difficult to keep their arm in the MRI scanner. Ok. It's not the best of the investigations. So don't rush into high level tests when there are simpler things that will give you similar information. But MRI is very good. Of course to, uh, look at soft tissue problems of the shoulder. It can show you problems with the labrum with the rotator cuff. If there are cysts around the shoulder, MRI will show it quite nicely. It will allow you to quantify muscle atrophy tumors around the shoulder. It is also quite good for preoperative planning when there are big tendon tears. Uh So if I'm operating on a big tendon tear, I'll sometimes do MRI scan. Ok. Next slide. CT scans are mainly reserved for bones for fractures or when I'm suspecting bone loss in the shoulder. So when I'm planning shoulder replacements or tumor reconstruction. So that's when CT scan comes into play. Next slide and then nerve conduction tests. The brachial plexus is very close to the shoulder. All right, it's just on the medial side of the coracoid. So everything on the lateral side of the coracoid is called the safe side. And on the medial side of the coracoid for a shoulder surgeon is suicide because if I, if I accidentally start working on the medial side or if I don't have a clean view, there is bleeding and I accidentally veered off medial to the coracoid. That's not good. I'm going to prank the brachial plexus. I'm going to have some kind of arterial injury. But the most common things that we do for nerves around the shoulder is to do a nerve conduction study or an EMG study, typically done six weeks after an injury. Because if you do a nerve conduction study immediately after the injury to the nerve, it's not gonna give you information because the wallerian degeneration has not fully happened. It takes a good four weeks for that to happen for the nerve test, then to pick up a problem. Ok. So if you see someone with a nerve injury that's happened yesterday, don't start booking them for a nerve conduction study. It ain't gonna tell you much. Give them four weeks, then book them in. It also gives you time because in that four weeks, if it's a neuropraxia, it might start waking up. So give it a few weeks next slide. That's it.