Shoulder Musculoskeletal Ultrasound

High-resolution ultrasound is an accurate, dynamic and inexpensive first-line tool for evaluating the rotator cuff and periarticular soft tissues. It depicts the supraspinatus, infraspinatus, subscapularis and long head of biceps tendons, the subacromial-subdeltoid bursa and dynamic impingement, with diagnostic accuracy for full-thickness cuff tears approaching that of MRI in experienced hands.

Indications

Suspected rotator cuff tendinopathy or partial/full-thickness tear
Subacromial impingement and painful arc
Long head of biceps tendinopathy, subluxation or dislocation
Subacromial-subdeltoid bursitis and calcific tendinopathy
Suspected joint or bursal effusion and guided injection/aspiration
Postoperative cuff assessment and dynamic instability evaluation

Contraindications & Cautions

No absolute contraindications; ultrasound is safe and non-ionising
Limited utility for intra-articular labral and bony pathology, which requires MRI/MR arthrography or CT
Restricted shoulder movement may limit standardised positioning and dynamic testing
Large body habitus and deep structures reduce resolution

Patient Preparation

No specific preparation required
Patient seated on a rotating stool with the arm accessible for positioning
Explain the standardised positions and dynamic manoeuvres that will be requested
Compare with the asymptomatic contralateral shoulder when findings are equivocal
For guided injection, prepare a sterile field and consent

Technique & Parameters

High-frequency linear array 9-18 MHz; a smaller footprint helps in the biceps groove and rotator interval
Long head of biceps in transverse and longitudinal planes within the bicipital groove
Subscapularis with the arm in external rotation; supraspinatus in the modified Crass position (hand on ipsilateral back pocket)
Infraspinatus and teres minor over the posterior shoulder; assess bursa and greater tuberosity cortex
Keep the beam perpendicular to the tendon to avoid anisotropy that mimics a tear
Dynamic imaging: internal/external rotation and abduction to assess impingement and cuff excursion

Systematic Review

Long head of biceps tendon position, echotexture and fluid in the sheath
Subscapularis tendon integrity and continuity in external rotation
Supraspinatus footprint for thickness, hypoechoic/anechoic clefts and cortical irregularity
Infraspinatus and teres minor for tears and atrophy
Subacromial-subdeltoid bursa for thickening or fluid and dynamic bunching on abduction
Acromioclavicular joint and greater tuberosity cortex for degeneration and enthesopathy

Key Findings & Significance

Full-thickness tear: focal anechoic/hypoechoic defect spanning bursal to articular surface, non-visualisation of tendon, cartilage interface sign
Partial-thickness tear: hypoechoic or anechoic defect on the articular or bursal surface not spanning the full thickness
Tendinosis: thickened hypoechoic tendon with loss of fibrillar pattern and no discrete cleft
Calcific tendinopathy: echogenic focus with or without posterior shadowing within the tendon
Subacromial-subdeltoid bursitis: bursal thickening or fluid >2 mm with dynamic bunching indicating impingement
Biceps pathology: sheath fluid, tendon subluxation/dislocation from the groove or empty groove

Differential Considerations

Focal cuff defect: full- vs partial-thickness tear vs anisotropy artifact vs intrasubstance tendinosis
Shoulder pain with fluid: bursitis vs joint effusion vs biceps tenosynovitis
Echogenic tendon focus: calcific tendinopathy vs intratendinous gas vs surgical anchor
Impingement: subacromial (external) vs internal impingement vs adhesive capsulitis
Cuff atrophy: chronic tear vs suprascapular neuropathy vs disuse

Pearls & Pitfalls

Anisotropy is the commonest pitfall; rock the probe to keep the beam perpendicular before calling a hypoechoic tear
The cartilage interface sign and joint/bursal fluid tracking through a defect support a full-thickness tear
Dynamic imaging uniquely demonstrates impingement and reducible biceps subluxation that static imaging misses
Measure tear width and retraction and note fatty muscle atrophy to guide surgical planning
Ultrasound is insensitive to labral and articular pathology; escalate to MRI when instability is suspected

Structured Report

State transducer, positions used and whether dynamic and comparison imaging were performed
Report each tendon (supraspinatus, infraspinatus, teres minor, subscapularis, biceps) individually
Describe tears by surface, thickness, dimensions and retraction; note muscle atrophy
Report bursal fluid/thickening, calcifications and dynamic impingement
Give an impression and recommend MRI or orthopaedic referral where indicated

References

ACR-AIUM-SPR-SRU Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination
European Society of Musculoskeletal Radiology (ESSR) Ultrasound Guidelines: Shoulder
Jacobson JA. Fundamentals of Musculoskeletal Ultrasound, Elsevier
Beggs I et al. Shoulder Ultrasound. Radiographics reviews of rotator cuff sonography

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

Shoulder Musculoskeletal Ultrasound

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References