- The best way to identify tears of the Subscapularis tendon is to look at the Sagittal PDFS first.
- Start at the bicipital groove and the immediate next slice medially will be subscap insertion ( Pink arrows) on the lesser tuberosity ( Yellow arrows look for flattening of the humeral head and oblique appearance of facet).
- The subscapularis tendon insertion is quite wide so you should see tendon attached to bone on 3- 4 slices. .
- There should be NO fluid in the tendon or between tendon and bone on any of these slices.
- Most tears occur at the superior portion of the tendon.
- Once the subscap insertion on the lesser tuberosity is over ( 3-4 slices) then you will see fluid ( Orange Arrows) between subscap and bone which is joint fluid and normal.
Image Above: Focal Partial tear at insertion ( Orange Arrow). Note shape of humeral head ( lesser tuberosity) which is flattened and oblique at the subscapularis insertion. Pink arrows demonstrate normal Subscap tendon with no high signal in tendon or at interface with bone.
Image Above: Orange arrows multiple tears in subscapularis tendon. Easier to appreciate this on the sagittal scans.
Image Above: Complete full thickness tear ( Orange arrows). No fibres seen inserting onto lesser tuberosity ( bald man appearance). Compare with normal.