• See Also
  1. Musculoskeletal Ultrasound
  2. Median Nerve Block at Elbow
  3. Radial Nerve Block at Elbow
  4. Ulnar Nerve Block at Elbow
  • Images
  1. neuroPeripheralArm.jpg
  2. usElbow_antTransAntecub.png
  3. usElbow_antTransAntecubCaudal.png
  4. usElbow_LatEpiconLong.png
  5. usElbow_MedEpiconLong.png
  6. usElbow_PostMedialTransverse.png
  7. usElbow_PostMidLongTricepsInsert.png
  • Technique
  • Anterior Elbow
  1. Positioning
    1. Patient lies supine with arm resting at side
    2. Elbow slightly flexed and wrist supinated (consider towel roll under wrist)
  2. View 1: Antecubital space (probe transverse or short axis, SAX)
    1. Landmarks
      1. Humerus capitulum and trochlea form dual parallel lines with posterior shadowing
    2. Mnemonic: Pyramid
      1. Bicipital tendon sits atop the pyramid centrally
      2. "Pyramid walls" contain the brachialis Muscle
        1. Draw a lateral pyramid wall between bicipital tendon to the radial head (or humeral capitulum)
        2. Draw a medial pyramid wall between bicipital tendon to the ulnar notch
      3. Brachialis Muscle pyramid is flanked by the brachioradialis Muscle laterally (radial aspect)
        1. Radial Nerve sits between the Brachialis Muscle and the brachioradialis Muscle
      4. Brachialis Muscle pyramid is flanked by the pronator teres medially (ulnar aspect)
        1. Brachial artery and Median Nerve are located in this region
    3. Images
      1. usElbow_antTransAntecub.png
    4. Components
      1. Lateral (radial aspect of volar arm)
        1. Brachioradialis Muscle
        2. Radial Nerve (embedded in fascia)
      2. Mid
        1. Bicipital tendon (small, most superficial)
        2. Brachialis Muscle
        3. Capitellum of Humerus (articulates with radial head)
      3. Medial (ulnar aspect of volar arm)
        1. Brachial artery (most superficial)
        2. Pronator teres
        3. Median Nerve (embedded in fascia, just medial and deep to the brachial artery)
        4. Trochlea of Humerus (articulates with ulnar coronoid anteriorly and olecranon posteriorly)
    5. Structures that may be followed distally (rotate to long access)
      1. Bicipital tendon (to its distal two part insertion)
      2. Radial Nerve (into two branches)
      3. Median Nerve
  3. View 2: Antecubital Space short axis (SAX) tilted slightly cephalad from view 1
    1. Positioning
      1. Patient flexes elbow to 90 degrees
    2. Images
      1. usElbow_antTransAntecubCaudal.png
    3. Landmarks
      1. Brachial artery (superficial)
      2. Anterior fat pad
      3. Humeral coronoid fossa
    4. Significance
      1. Anterior fat pad displacement (Fracture) is more prominent on Ultrasound than Sail Sign on xray
  • Technique
  • Bicipital tendon visualization
  1. View 1: Anterior long axis
    1. Follow bicipital tendon from distal Humerus region and antecubital space to dual proximal radius insertion sites
  2. View 2: Medial long axis or Pronator Window (most reliable)
    1. Position elbow flexed to 90 degrees
    2. Start distal to medial epicondyle in long axis
    3. Gradually slide the probe anteriorly until brachial artery is visible in long axis
    4. Bicipital tendon will run in parallel, immediately deep to the brachial artery
  3. View 3: Lateral long axis
    1. Position elbow flexed to 90 degrees
  4. View 4: Posterior long axis (dorsal approach)
    1. Best for distal bicipital tendon visualization (last 1-2 cm) and injection
    2. Position elbow flexed to 90 degrees
    3. Pronate the Forearm to expose the bicipital tendon
  • Technique
  • Medial View
  1. Patient Positioning
    1. Elbow extended and Forearm supinated (thumb lateral)
    2. Ultrasound probe indicator toward Shoulder (left image is proximal, toward Shoulder)
  2. Medial Elbow Image (Medial Epicondyle)
    1. usElbow_MedEpiconLong.png
  3. View: Long Axis (LAX) of medial elbow
    1. Superficial structures
      1. Common flexor tendon (attaches to Humerus)
      2. Flexor tendon Muscle
        1. Flexor digitorum superficialis (FDS, contiguous with tendon, and superficial)
        2. Flexor carpi radialis (deep to flexor tendon and FDS, superficial to ulnar collateral ligament)
    2. Deep structures
      1. Distal Humerus (medial epicondyle proximal to trochlea)
      2. Ulnar collateral ligament (triangular)
        1. May require increased downward probe pressure and probe rotation for better visualization
      3. Joint line (gap between trochlea and ulna)
      4. Proximal ulna (deeper)
  • Technique
  • Lateral View
  1. Patient Positioning
    1. Patient sitting or lying, elbow flexed 60-90 degrees and Forearm pronated (palm down, thumb medial)
    2. Ultrasound probe indicator toward Shoulder (left image is proximal, toward Shoulder)
      1. Scan plane should be lateral to medial (parallel to floor, aiming towards medial epicondyle)
  2. Lateral Elbow Image (Lateral Epicondyle)
    1. usElbow_LatEpiconLong.png
  3. View: Long Axis (LAX) of lateral elbow
    1. Humerus (lateral epicondyle, capitellum)
    2. Common extensor tendon (superficial, inserts on lateral epicondyle)
    3. Joint space
    4. Radius (radial head)
      1. Rotation visible on supination and pronation dynamic maneuvers
  • Technique
  • Posterior View
  1. Patient Positioning
    1. Patient sitting with hand pronated, palm on hip (thumb medial) and elbow flexed posteriorly (crab position) OR
    2. Patient lying with elbow flexed and propped on pillow
  2. View 1: Short Axis (SAX) of Ulnar Nerve in ulnar groove (posterior-medial elbow)
    1. usElbow_PostMedialTransverse.png
    2. Humerus (Medial Epicondyle)
    3. Ulnar groove
      1. Ulnar Nerve (normal cross sectional area: 7mm)
      2. Nerve may be tracked in short axis
    4. Ulna (Olecranon)
  3. View 2: Long Axis (LAX) of Triceps Muscle, tendon and insertion at ulna (medial olecranon)
    1. usElbow_PostMidLongTricepsInsert.png
    2. Superficial structures
      1. Triceps tendon
      2. Ulna (Olecranon) with tendon insertion
    3. Deeper structures
      1. Humerus
      2. Ulnar groove (with fat pad)
      3. Triceps Muscle (deep to triceps tendon)
        1. May appear hypoechoic (do not mistake for joint or bursal fluid)
  4. View 3: Short Axis (SAX) of Posterior Fat Pad (and triceps tendon)
    1. Triceps tendon (superficial)
    2. Triceps Muscle (hypoechoic, deeper)
    3. Olecranon fossa with posterior fat pad
  • References
  1. Jacobson (2013) Musculoskeletal Ultrasound, Elsevier, Philadelphia, p. 72-109
  2. Moore (2013) Upper Extremity Ultrasound Video, GCUS
  3. Moore (2015) Sonography of the Extremities, 4th ed, p. 25-34
  4. Lento (2016) Elbow, GCUS Musculoskeletal Ultrasound Course, St Pete's Beach, attended 1/25/2016