II. Indications

III. Advantages

  1. Much less expensive than MRI
  2. Much better tolerated than MRI
  3. High accuracy compared with MRI for larger Rotator Cuff Tear diagnosis

IV. Disadvantages

  1. Does not assess other Shoulder structures (e.g. Shoulder labrum)
  2. Not yet widely accepted for rotator cuff evaluation

V. Efficacy

  1. Accuracy is dependent on technician experience
  2. As good or greater accuracy than MRI for large partial and full thickness Rotator Cuff Tears (MRA is most accurate)
    1. Test Sensitivity: 67% for partial thickness and 97% for full thickness tears
    2. Test Specificity: >93%

VII. Preparation

  1. Ultrasound Probe
    1. High frequency linear probe
  2. Patient position: Sitting
    1. Patient sits with arm flexed at elbow, resting at side
    2. Wrist supinated (palm up, thumb laterally)
    3. Patient sits facing the Ultrasound screen
    4. Examiner stands facing the Ultrasound screen, behind the patient

VIII. Technique: Anterior Humerus - Bicipital tendon (home position and external rotation)

  1. View 1: Anterior Humerus - transverse probe or 9:00 (home view, short axis or SAX for bicipital tendon)
    1. usShoulder_AntSaxHome.png
    2. ShoulderAnteriorBiceps.jpg
    3. Humerus greater tuberosity
      1. Subscapularis insertion attaches here
    4. Bicipital groove (lateral)
      1. Contains Bicipital tendon (hyperechoic)
      2. Transverse ligament crosses over the groove and offers meager support to hold the biceps tendon in place
      3. Shallow groove <3mm may predispose bicipital tendon to sublux from groove
      4. Bicipital groove also contains anterior circumflex artery
      5. Follow bicipital tendon inferiorly or distally down the anterior Humerus in short axis
        1. Ultimately disappears at pectoralis major insertion
    5. Humerus lesser tuberosity (medial)
  2. View 2: External Rotation
    1. Observe biceps tendon in SAX while externally rotating arm
    2. Biceps tendon may sublux with external rotation or may be persistently dislocated medially
  3. View 2: Anterior Humerus - longitudinal probe or 12:00 (long axis or LAX for bicipital tendon)
    1. usShoulder_AntLaxBiceps.png
    2. Follow bicipital tendon down the anterior Humerus in long axis

IX. Technique: Anterior Humerus - Subscapularis (external rotation)

  1. Positioning
    1. Arm in external rotation and slight abduction
    2. Contrast with arm at rest position (as above) which demonstrates bicipital tendon
  2. View 1: Anterior Humerus - transverse probe or 9:00 (long axis or LAX for subscapularis)
    1. usShoulder_AntSaxSubscap.png
    2. Deltoid Muscle (most superficial)
    3. Subscapularis Muscle
      1. Subscapularis Muscle insertion at Humerus medial to bicipital tendon
      2. Movement (and impingement) may be observed dynamically with active external rotation
    4. Humerus (deep)
  3. View 2: Anterior Humerus - Longitudinal probe or 12:00 (short axis or SAX for subscapularis)
    1. Deltoid Muscle (most superficial)
    2. Subscapularis Muscle
      1. Muscle body with appear as a dotted line of three interspersed tendons (SAX view)
      2. Observe for defect or tear in subscapularis Muscle
      3. Confirm defects in 2 views and with probe adjustment as artifact or anisotropy may appear as defect
    3. Humerus (deep)

X. Technique: Superior Humerus - AC Joint and Supraspinatus (arm abduction)

  1. Images
    1. usShoulder_TopAc.png
    2. usShoulder_TopLaxInfraspinatus.png
    3. orthoShoulderSuperior.png
  2. View 1: Superior Humerus - transverse probe or 9:00 directed down to AC (long axis or LAX for AC Joint)
    1. Clavicle
    2. AC Joint
      1. Observe for osteophytes and defects
    3. Subacromial space
      1. Supraspinatus tendon may be be visualized descending under AC joint on Shoulder Abduction
      2. Supraspinatus tendon should be 6mm or less in width
      3. Observe tendon for "bunching up" or catching as it passes under AC Joint
    4. Acromion

XI. Technique: Anterior Humerus - Supraspinatus (Crass Position)

  1. Positioning
    1. Arm internally rotated with hand resting across the low back (Crass Position)
      1. Modified Crass: Patients palm against their ipsilateral low back over iliac
    2. Probe position will require fine adjustment
  2. View 1: Anterior Humerus - 10:00 to 11:00 (long axis or LAX for supraspinatus)
    1. usShoulder_AntLaxSupraspinatus.png
    2. ShoulderAnteriorRotatorCuff.jpg
    3. Supraspinatus insertion at Humerus has a characteristic appearance
      1. Inserts into a flat slope (foot print) at the top of the Humerus (superior facet)
      2. Insertion region (within 1 cm) accounts for 90% of rotator cuff pathology
    4. Any observed defect should be confirmed in 2 views and by adjusting the probe (rotation, tilt, heel-toe)
      1. Defects will be articular sided (deep), intrasubstance or bursa sided (superficial)
  3. View 2: Anterior Humerus - 8:00 (short axis or SAX for supraspinatus)
    1. usShoulder_AntSaxSupraspinatus.png
    2. Supraspinatus tendon overlies Humerus appearing similar to a tire on rim (Humerus)

XII. Technique: Anterior Humerus - Rotator Cuff Interval

  1. Positioning
    1. Arm internally rotated with hand resting across the low back (Crass Position)
  2. View 1: Anterior Humerus - Transverse Probe or 9:00 (bicipital groove)
    1. Subscapularis insertion
      1. Most medial
    2. Bicipital groove (between the subscapularis and the supraspinatus, 3 structures)
      1. Bicipital tendon (long head)
      2. Coracohumeral ligament
      3. Superior glenohumeral ligament
    3. Supraspinatus insertion
      1. Inserts at superior facet of greater tuberosity
      2. Also shares one third of middle facet with infraspinatus
    4. Infraspinatus insertion
      1. Inserts at middle facet of greater tuberosity
    5. Teres Minor (rarely Clinically Significant)
      1. Inserts at inferior facet

XIII. Technique: Posterior Shoulder (posterior glenohumeral joint)

  1. Positioning
    1. Patient positions arm across their chest or in their lap
  2. View 1: Transverse probe (long axis for infraspinatus)
    1. Infraspinatus tendon and insertion at Humerus
      1. Spinoglenoid fossa (Suprascapular artery, Suprascapular nerve)
    2. Follow tendon down postero-lateral Shoulder
    3. Rotate probe to transverse at lateral Shoulder
      1. Visualize humeral surface beneath infraspinatus (hill-sacks deformity appears as divot)
  3. View 2: Supraspinatus Impingement
    1. Using the same probe position as above
    2. Patient repositions their arm at side
    3. Supraspinatus is now visualized in the same position infraspinatus was in view 1
    4. Allows for dynamic testing for supraspinatus impingement
      1. Passively abduct (and extend the arm) while observing the supraspinatus move on Ultrasound

XIV. References

  1. Chappell (2016) Musculoskeletal Ultrasound Course, , Gulf Coast Ultrasound, St. Pete's Beach, FL
  2. Moore (2013) Upper Extremity Ultrasound Video, Gulf Coast Ultrasound
  3. Burbank (2008) Am Fam Physician 77:453-60 [PubMed]
  4. Dinnes (2003) Health Technol Assess 7:1-166 [PubMed]

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