 Hello everyone, I am Dr. Chaitari Parekh, consultant musculoskeletal interventional radiologist after the amazing video on the MRI anatomy of the rotator cuff. Today we will be discussing MRI in rotator cuff tendinosis and tears and how to create a report that is surgically relevant. Hope you enjoy the video. This is a proton density sagittal image of the shoulder showing the four rotator cuff muscles. This is the glenoid with the coracoid process and this is the spine of the scapula. So this is anterior and this is posterior. Now between the coracoid process and the spine of the scapula is the supraspinatus fossa which contains the supraspinatus muscle. Anteriorly you have the sub scapularis muscle, posteriorly there are two muscles the superior one is infraspinatus and the inferior one is steedis minor muscle. Now when you come laterally you start to see the humeral head with the rotator cuff tendons around the humeral head and this is what the tendons look like. So approximately at 12 o'clock position you have the supraspinatus tendon and the conjoined tendon anteriorly is the sub scapularis tendon anteriorly is the biceps tendon which is abutting the humeral head posteriorly is the infraspinatus tendon and posterior inferiorly is the teres minor tendon. Now one important thing to note is that sub scapularis is a multi-pinate tendon that is it has multiple tendons and functionally it is not a single tendon rather functionally it consists of two parts that is the superior sub scapularis and the inferior sub scapularis. Now on the sagittal image you can see all the rotator cuff tendons besides that on the coronal image the supraspinatus tendon is very well visualized which is seen attaching to the greater tuberosity of the humerus whereas on the axial images you can see the sub scapularis and the infraspinatus tendons. So anteriorly you can see the entire length of the sub scapularis tendon with the biceps tendon in the bicepital groove posteriorly you can see the entire infraspinatus tendon. Now one thing to keep in mind is please have the arm of the patient in the neutral or slightly externally rotated position while performing the scan. Please do not keep the arm in internally rotated position because when you do so it is very difficult to assess the sub scapularis and the anterior supraspinatus tendons. It is important to know the parts of the tendon because you need to put them in the report while describing a tear. So in this supraspinatus tendon this is the footprint or the emphasis that is the point where the tendon attaches to the bone. This is the critical zone of the tendon which is approximately 1 to 1.5 centimetre from the emphasis and it is particularly seen and important in the supraspinatus tendon. It was hypothesized that the critical zone is hypervascular and prone for degenerative tears. However with recent research the hypervascularity of the critical zone is a topic of debate. Nevertheless it is one of the common sites for the supraspinatus tendon tear and the third one is the myotendinous junction. Usually traumatic tears happen at the myotendinous junction. Now we will discuss the pathogenesis behind tendonosis and tear and what are their MRI appearances. So this is the humeral head with the supraspinatus tendon attaching to it. Now we will concentrate only on the tendon. So tendon is made up of collagen fibres as depicted by these orange lines in the graphic presentation. Between the collagen fibres are water molecules which are nothing but these white coloured rounded structures. Normally the water molecules are so tightly bound that they cannot move around and hence it appears jet black on the MRI image. In case of tendonosis there is disorientation and degeneration of the collagen fibres and as a result of which there is some movement of the water molecules but this still cannot move freely. In case of a tear there is disruption of the collagen fibres and now the water molecules are free to move around so this is a normal MRI tendon which appears jet black in colour. This is a tendon which shows tendonosis so there is some hyper intense signal within the tendon but it is not as bright as the adjoining Bersil fluid, the subacromial Bersil fluid and in case of tear you can see that the signal is as bright as the adjoining subacromial Bersil fluid. Now whenever you are assessing rotator cuff tendons first thing you need to decide whether there is tendonosis or tear. In case of tears you need to know whether it is a partial thickness tear or a full thickness tear. The partial thickness tears can further be divided into articular sided, interstitial and Bersil sided tears. Now we will look at each of these individually. So whenever there is tendonosis you need to grade it as mild, moderate or severe. So this patient has mild tendonosis as you can see there is some hyper intense signal within the tendon while this patient has moderate tendonosis where there is increased length of the tendon involved and the signal is brighter as compared to this patient and this patient has severe tendonosis where the signal is further brighter but point to note is that the hyper intense signal within the tendon is still not as bright as the fluid in the adjoining subacromial Bersil which means that this is tendonosis and not a tear. In tendonosis there is accumulation of mucoid material within the tendon and sometimes this can track along the path of least resistance as in this case it is tracking up to the myotendinous junction with formation of intratendinous cystic change. Similarly this patient has subscapularis tendonosis with formation of a ganglion cyst towards the myotendinous junction. Now just like the mucoid material can track towards the myotendinous junction similarly it can also enter into the bone with formation of intra-austrious cystic changes. Now intra-austrious cystic changes can be as tiny as these or they can be as large as this one. It is important to mention the location and size of the intra-austrious cystic change because the arthroscopic repair of a rotator cuff tendon involves placing of an anchor in the humeral head. There are sutures that come out of this anchor and these sutures are then tied to the torn tendon and the tendon is fixed back to the bone. Now if the anchor is placed in the intra-austrious cystic area like in this case the anchor will not be held firmly in the bone and as soon as the patient uses the arm the anchor will come out and result into tendon retail. This is another patient who had a large but multi-loculated intra-austrious cystic change. Along with that there was a tiny ganglion cyst at the myotendinous junction. Now sometimes the tendonosis is not just because of degeneration but there is presence of calcification and this is nothing but calcific tendonosis. Now you can see this hyper intense structure so calcium appears hyper intense on all the sequences so there is calcium at the emphasis of the supraspinitis tendon. It is also extending into the subacromial bursa resulting into the inflammation of the bursa and you can see that the bursa lining is thickened with fluid in the bursa and along with that there is deltoid edema. So actually this is a case of acute exacerbation of calcific tendonosis or rather calcific tendonitis. These patients will come to you with a classical history of sudden onset acute pain. Now we'll discuss about partial thickness tears so it can be articular sided, interstitial or bursal sided. We'll look at each of these so in articular sided tear this is what is a articular sided tear. So you can see that there is tear along the articular surface of the tendon but the bursal surface of the tendon is intact. Now it is also called as pasta. Do you think there is any correlation with the yummy Italian pasta recipe? No unfortunately not. It just stands for partial articular surface tendon evulsion. So this patient first of all you don't have to mention the term pasta in your report. What is more important is to describe the tear. So how are you going to describe this tear? So this patient has an approximately 75% thickness partial articular sided tear at the supraspinitis emphasis. So this is how you'll describe the tear. If you see there are some bursal fibers which are intact in this patient and this is what the tear appears on a sagittal image and this is the anterior posterior dimension. Now similarly you have bursal sided tears where the articular surface is intact. Now they could not put up a fancy name for this so they decided to call it anti-pasta. So this is a approximately 75% thickness bursal sided tear where you can see that the articular surface or the articular fibers are intact to some extent and there is fluid in the adjoinings of acromial bursa. Now in case of interstitial tear there is tear within the substance of the tendon. The articular surface and the bursal surface are intact. Now these tears are present in the substance of the tendon with obviously intact articular and bursal surfaces and as a result they cannot be picked up by an orthopedic surgeon on arthroscopy. Because these tears play hide and seek with the orthopedic surgeon it is very important for us radiologists to report these tears. So here you can see the bursal surface of the tendon is intact. The articular surface of the tendon is intact but there is a linear hyper intense signal within the tendon and if you appreciate the signal of this particular linear hyper intensity is same or is as bright as the adjoining fluid in the subacromial bursa. So this is nothing but a long interstitial tear in the supraspinitis tendon. Now one more important tear is a rim-rend tear which are small partial thickness articular sided tears or pasta and these tears are commonly found in the anterior most fibers of the supraspinitis tendon. Now this is one of the common site for a partial thickness tear to begin in case of a supraspinitis tendon and if missed these tears can progress into large partial thickness tears or even a full thickness tear. So this is a rim-rend tear and this is the entire bicep tendon and on the coronal image just next to the bicep tendon you can find the anterior most fibers of the supraspinitis tendon. However many a times it is difficult to pick up these tears on coronal images and therefore it is very important to keep an eye for these tears on sagittal images where you can see the subscapularis tendon the bicep tendon and just next to the bicep tendon you can see the tear. So this is the rim-rend tear. Now we'll discuss full thickness tears. So this patient if you'll see the emphasis is intact but there is a full thickness tear in the critical zone of the supraspinitis tendon and the tear is not much retracted. This is the anterior posterior dimension of the tear on the sagittal image. Against this this patient has a full thickness tear from the emphasis and the tendon is almost retracted up to the glenohumeral joint and when you see on the sagittal image you can see that the entire supraspinitis and infraspinitis tendon is not visualized what you can see is the pterisminal tendon. So now it is important to mention the anterior posterior dimension of the tear which is this much in this particular case whereas in this case the anterior posterior dimension is a long one okay so it is a sum of these two deaths. Now it is important to give these anterior posterior dimension to the orthopedic surgeons because when the tear is small as in this case the repair is done with visually one or two anchors but when the tear is large the surgeon will require more anchors so he may actually use three anchors to repair these deaths. So if the surgeon knows the anterior posterior dimension before the surgery he can accordingly prepare for the surgery and also just remember more the anchors more is the costing of the surgery and so accordingly he can also inform the patients. Now next is to mention the exact retraction of the tone tendon in centimeters from the emphasis and also the level to which the tone tendon is retracted now what do I mean by the level so first let me just tell you how to measure the retraction of the tendon in centimeters so you just take from the greater tuberosity and you go up to the retracted tendon margin so this is what is the retraction in terms of centimeters by level I mean this tendon is retracted up to the mid-humeral head level this is retracted up to the glenohumeral joint line and this is retracted nearly medial to the glenoid. Next is a full thickness delaminating tear now it is important to identify these tears delaminating tear is nothing but a horizontal tear that divides or that is present within the tendon substance that will divide the tendon into superficial and deep fibers or as in this case bursal and articular fibers so you have to identify these tears and also mention the retraction of each of the fibers so this is what the superficial fibers is retracted up to whereas the deeper fibers are retracted further medially it is important to mention the presence of the delaminating tear as well as the level to which the superficial and deep fibers have been retracted because if the orthopod is not aware that the deeper fibers have been retracted further medially he will land up repairing only the superficial fibers and in fact most of the strength of the supraspinatus comes from the deeper fibers so eventually when the patient will start using his arm there are high chances that he will develop a re-tear in the repaired tendon. Now this is a full thickness myotendinous junction tear as you can see over here and these tears are usually they tend to be traumatic now we'll discuss subscapularis tears there are some things in subscapularis tears which are different as compared to a supraspinatus or an infraspinatus tear so this is a normal subscapularis tendon which goes and attaches to the lesser tuberosity this is the bicep's tendon in the bicepital groove but there is a school of thought which says that one of the tendon slip from the superior subscapularis tendon goes underneath or deep to the bicep's tendon in the bicepital groove and attaches to the greater tuberosity now this provides medial stability to the bicep's tendon and prevents its medial dislocation or subluxation so whenever there is a tear of the superior subscapularis tendon the bicep's tendon tends to dislocate medially towards the glenohumeral joint so in this patient if you see the bicep the bicepital groove is empty in fact the tendon is dislocated medially close to the glenohumeral joint and what you notice is there is a full thickness subscapularis tear now this doesn't mean that all patients with a subscapularis tear will have a dislocated bicep's tendon as in this case you can see that the patient has intact superficial fibres but the deep fibres are toned yet the bicep's tendon is not dislocated medially instead it is just mildly subluxed in fact it is purged on the medial lip of the bicepital groove just keep in mind that mild medial subluxation of the bicep's tendon can also occur with moderate to severe subscapularis tendinosis now this is an interstitial subscapularis tear and here you can see that this is a delaminating subscapularis tear where the bicep's tendon is actually dislocating in the substance of the subscapularis tendon next point to report is the muscle atrophy which is decided by the line joining the coracoid process to the spine of the scapula for this supraspinatus muscle and line joining the spine of the scapula to the inferior tip of the scapula for the infraspinatus muscle so in case of a normal muscle you can see that the muscle extends above this line in case of mild atrophy the muscle extends up to the line in case of moderate atrophy the upper margin of the muscle is below the line and in case of severe atrophy the muscle is actually situated in a corner of the supraspinatus fossa now next important thing to mention is fatty infiltration of the muscles which is classically graded as per the Gottelier's classification so again we look at the supraspinatus muscle and there is no fat so this is grade zero or normal few fatty streaks indicate grade one more fat as compared to grade one but the fat is still less than the muscle that's grade two the amount of fat and the amount of muscle is equal that's grade three and the fat is more than the muscle that is grade four fatty infiltration and muscle atrophies are important prognostic indicators with fatty infiltration being a more important prognostic indicator because following arthroscopic repair the muscle bulk and strength can be increased with postoperative rehabilitation and physiotherapy however fatty infiltration is usually irreversible so patients with higher grades of fatty infiltration have poor prognosis as in these two cases and they need longer periods of postoperative rehabilitation sometimes besides the rotator cuff tear biceps tendinosis can be a cause of pain so whenever you're reporting a patient with rotator cuff tear you need to mention the status of the bicep tendon as well because if it is tendinosed the surgeon prefers to do a tnotomy or a tnordesis of the bicep tendon so this is a normal bicep tendon here there is intrasubstant split and this tendon shows moderate to severe tendinosis again you can see that the intraarticular bicep tendon shows moderate to severe tendinosis now what are massive tears by definition it involves two or more tendons and it is more than 5 centimeter in any dimension but there are other criterias as well which are considered by the orthopedic surgeons which include marked muscle atrophy grade three or four fatty infiltration severe medial lateral retraction which is either up to or medial to the glenohumeral joint line reduced acromio-humeral distance that is distance between the acromion and humerus normally it is 7 to 14 millimeter whenever it is equal to or less than 6 millimeters it is reduced there is no fixed protocol for the treatment of massive tears some orthopods offer to operate on these tears some do not depending upon the clinical symptoms and the presence and absence of muscle atrophy and fatty infiltration however it is important to mention all these points in the report because massive tears are usually associated with poorer prognosis now the last topic to discuss is rotator cuff arthropathy which occurs in massive rotator cuff tears there is superior humeral head migration as a result of which there is reduced acromio-humeral distance this usually occurs because following massive rotator cuff tear there is unopposed action of the deltoid on the humerus which causes the superior humeral head migration there are degenerative changes in the superior aspect of the glenohumeral joint and there is femoralization of the humeral head and acetabularization of the under surface of acromion so now let's look at each of these findings so this is a normal supraspinatus tendon with a normal acromio-humeral distance which is 8.3 millimeters in this patient there is reduced acromio-humeral distance which is 5.1 millimeter plus as you can see you can identify the greater tuberosity very nicely in the normal patient whereas here there is flattening of the greater tuberosity which is called as femoralization of the humeral head and also there is pseudo-articular surface formation on the under surface of acromion this is known as acetabularization of the acromion and in this patient besides reduced acromio-humeral distance also there is conural loss in the superior humeral head and superior glenoid the inferior cartilage is still well seen so patients who develop osteoarthrosis secondary to massive rotator cuff tear they can undergo reverse shoulder arthroplasty as a treatment now confused what to report we have discussed a lot many things okay so now let's make things simpler so whenever you do an MRI for rotator cuff tendons you need to look whether there is tendinosis or tear in case of tendinosis see if it is mild moderate or severe in case of tear you need to see if it's a partial thickness tear or a full thickness tear in case of partial thickness tear you have to mention the percentage of the thickness or the percentage thickness of the tendon that is torn and you need to mention whether the partial thickness tear is articular sided bursal sided or interstitial and this is the checklist for the reporting of a tear so you need to mention all these points while describing a tear hi hope you've liked the video i hope this reporting pattern and lexicon helps you to make appropriate reports in your day-to-day practice if you have any queries regarding this topic you can type them in the comment section below and we will get back to you stay tuned for more such knowledge pack videos thank you