51-year-old male with right shoulder pain and functional limitation. The clinical history, duration of symptoms, trauma history, activity level, strength loss, and previous treatment are not provided.
Ultrasound examination of the shoulder demonstrates a relatively large full-thickness, partial-width tear of the supraspinatus tendon. The defect extends through the full tendon thickness but does not involve the entire tendon width. The remaining supraspinatus tendon portions show clear tendinopathic changes.
Within the subacromial-subdeltoid bursa, a hyperechoic structure is visible. This structure partially fills the supraspinatus tendon defect but does not have the typical appearance of a calcification. During ultrasound-guided active loading, the hyperechoic structure moves differently from the two remaining supraspinatus tendon portions. Therefore, it does not appear to represent intact supraspinatus tendon tissue.
Possible explanations for this hyperechoic bursal structure include organized hematoma, bursal debris, synovial or bursal thickening, reactive scar tissue, or displaced degenerative tendon or soft tissue material. Its exact nature cannot be determined with certainty on ultrasound alone.
The supraspinatus muscle shows sonographic signs of grade 2 fatty infiltration, with hyperechoic areas involving approximately half of the muscle belly. This is compatible with chronic muscle change secondary to rotator cuff pathology.
1. Final diagnosis
Relatively large full-thickness, partial-width tear of the supraspinatus tendon, with tendinopathic change of the remaining tendon portions. There is an unexplained hyperechoic structure in the subacromial-subdeltoid bursa, partly projecting into the tendon defect. The structure is not typical for calcification and does not show dynamic behavior consistent with normal supraspinatus tendon tissue. Sonographic signs of grade 2 fatty infiltration of the supraspinatus muscle are present, suggesting a more chronic rotator cuff lesion.
2. Differential diagnosis
The primary diagnosis is a chronic or subacute supraspinatus tendon tear with a full-thickness component over partial tendon width. The hyperechoic structure in the bursa or subacromial space may represent organized hematoma, bursal debris, synovial proliferation, reactive scar tissue, or displaced degenerative tendon material. Calcification is less likely based on the ultrasound appearance, but cannot be fully excluded without additional imaging. Associated subacromial bursitis or reactive bursal irritation may also be present. Additional intra-articular shoulder pathology, such as biceps pulley, labral, or chondral pathology, should be considered if symptoms are not fully explained by the rotator cuff findings.
3. Teaching points
A full-thickness, partial-width supraspinatus tear should be distinguished from a complete tear involving the entire tendon width. Dynamic ultrasound can help differentiate residual tendon tissue from mobile bursal or degenerative material within a tendon defect. Fatty infiltration of the supraspinatus muscle suggests chronicity and may influence prognosis and treatment planning. When an atypical hyperechoic structure is seen in the bursa, ultrasound can describe its morphology and dynamic behavior, but may not reliably define its exact tissue composition.
4. Injury/disease information
Supraspinatus tendon tears are part of the spectrum of rotator cuff disease and may occur after trauma, chronic overload, or progressive tendon degeneration. Larger tears may be associated with tendon retraction, muscle atrophy, and fatty infiltration. MRI can be useful to assess tear configuration, tendon quality, retraction, muscle atrophy, fatty infiltration, and the nature of atypical bursal tissue. Specialist assessment is particularly relevant when there is a large full-thickness component, functional weakness, suspected traumatic onset, or imaging signs of chronic muscle degeneration.
Marc is founder of, and trainer at, SonoSkills. SonoSkills is an organization dedicated to MSK ultrasound education. He's also an MSK Sonographer at EchoConsult in Roermond, the Netherlands.
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