48-year-old patient presenting with shoulder pain during abduction and overhead activity. Symptoms likely progressive and activity-related. Further clinical details not provided.
Ultrasound examination of the shoulder demonstrates findings consistent with subacromial pain syndrome (SAPS).
There is a moderate full-thickness tear involving the anterior portion of the supraspinatus tendon, limited in width (partial-width). The tendon shows marked degenerative changes with significant thickening and loss of the normal fibrillar architecture, consistent with advanced tendinopathy.
The subacromial-subdeltoid (SASD) bursa is mildly to moderately thickened and demonstrates synovial proliferation, indicating reactive bursitis.
The combined thickening of the supraspinatus tendon and SASD bursa results in narrowing of the subacromial space. During dynamic ultrasound with guided active abduction, there is clear primary subacromial impingement, with mechanical conflict between the supraspinatus–bursa complex and the undersurface of the acromial arch (fornix humeri).
Additionally, there is fluid distension of the biceps tendon sheath. This is likely secondary to intra-articular joint effusion and may be associated with the supraspinatus tendon tear.
1. Final diagnosis
Subacromial pain syndrome due to an anterior partial-width full-thickness tear of the supraspinatus tendon, with advanced degenerative tendinopathy and associated SASD bursitis with synovial proliferation, resulting in dynamic primary impingement. Associated biceps tendon sheath effusion likely reflecting intra-articular pathology.
2. Differential diagnosis
Consider high-grade partial-thickness tear versus full-thickness tear if tendon continuity is difficult to assess. Isolated bursitis or primary biceps tenosynovitis may also be considered, though less likely given the associated cuff tear.
3. Teaching points
Partial-width full-thickness tears may be subtle but clinically significant. Advanced tendinopathy contributes to tendon thickening and impingement. Dynamic ultrasound is essential to demonstrate functional subacromial impingement. Fluid in the biceps sheath often reflects intra-articular pathology rather than isolated biceps disease.
4. Injury/disease information
Subacromial pain syndrome is a multifactorial condition involving rotator cuff pathology, bursitis, and mechanical impingement. Degenerative changes in the supraspinatus tendon can progress to tearing, which may lead to altered shoulder biomechanics and secondary inflammatory changes, including bursal thickening and joint effusion.
Marc is founder of, and trainer at, SonoSkills. SonoSkills is an organization dedicated to MSK ultrasound education. He's also an MSK Sonographer at the Laurentius Hospital in Roermond, the Netherlands.
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