There are several well recognised sonographic 'signposts' for a potential supraspinatus tear. I found these extremely useful signposts to have in your mind when you are learning how to perform an ultrasound scan of the shoulder, particularly as the supraspinatus is often the site of pathology. There are several examples of supraspinatus ruptures and tears on this website, within the image gallery and shoulder case studies
This is certainly not an original piece of work, and is a topic that has previously been repeatedly covered in many texts and academic papers. It is however a very useful reference point for those new to using ultrasound, and a useful addition to the website!
It is well recognised that it is possible to have pathological findings in asymptomatic shoulders, and I am sure those of you who have scanned shoulders will agree with this point. This is particularly true of rotator cuff tears in older age groups and distended subacromial bursae. Review this article by Girish et al (2011) for more information regarding asymptomatic pathology.
I am therefore not saying that a reliance on the 'signposts' below is required, but they do provide a useful reference that should be incorporated into your clinical reasoning of a patients presentation. For example a long head of biceps effusion, in a younger patient following trauma should raise suspicions. Demonstrated in this case of greater tuberosity fracture.
Indirect signs of supraspinatus tears
Joint effusion and bursal fluid
Hollister et al (1995) found that the presence of bursal fluid and a glenohumeral joint effusion had a high positive predictive value for the presence of a rotator cuff tear. The biceps tendon sheath communicates directly with the glenohumeral joint and is therefore a useful reference point for the presence of a glenohumeral joint effusion. A longitudinal and transverse biceps sheath effusion can be seen in Figures 1 and 2. A joint effusion is often best visualised in the posterior aspect of the glenohumeral joint, particularly in the region of the spinoglenoid notch (Figure 3).
A bursal effusion is often a common sign, even in asymptomatic shoulders. A significant bursal effusion (Figure 4) is often considered when separated by greater than 2mm (Hollister et al, 1995).
Loss of tendon outline/ thininng and Deltoid indentation
Loss of normal tendon outline with possible indentation of the superior Deltoid are also suggested indicators of underlying supraspinatus pathology. A clear loss of the normal superior concavity of the tendon should raise suspicion of underlying tendon tearing. These findings can help differentiate from a degenerative tendon which will likely have a normal tendon outline, but may be thickened or have a hypoechoic echotexture. The images below ( Figure 5, Figure 6)demonstrate a transverse and longitudinal view of these signs.
When cortical irregularity is visible near to a hypoechoic region of the tendon then it is likely that a tear is present. This is clearly visible in the following images.
Cartilage Interface sign
In a normal tendon it is possible to visualise a slightly hyperechoic line as the tendon interfaces with the hyaline cartilage of the humeral head. When the adjacent supraspinatus tendon is torn, absent or hypoechoic, this is more visible (Figure , and is a indirect sign of supraspinatus pathology.