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Subacromial Bursa Injection

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Other Names

  • Subacromial Bursa Injection
  • Subdeltoid Bursa injection
  • Subacromial-Subeltoid Bursa Injection

Illustration of the subacromial bursa anatomy[1]


  • This page reviews the subacromial bursa injection, sometimes called the subdeltoid bursa

Key Points

  • This is generally considered a very safe injection as there is no major neurovascular structure nearby
  • Can be performed with palpation or ultrasound guidance


  • Subacromial Bursa
    • Large synovial space that covers the whole rotator cuff like a cap
    • Lies in the subacromial region, between the superior aspect of the supraspinatus tendon, inferior surface of the acromion
    • Function: reduces friction, facilitates movement between the supraspinatus and acromion during abduction
    • Does not communicate with the glenohumeral joint when tendon is intact

Palpation vs Ultrasound Guidance

  • One study of palpation guidance found only 49% of injections filled the bursa, 87% infiltrated regional structures[2]
  • There are no studies looking at ultrasound guidance or comparing the two techniques

Bursal fluid is noted in this sagittal plane sonogram[3]



  • Absolute
    • Anaphylaxis to injectates
    • Overlying cellulitis, skin lesion or systemic infection
    • Septic Bursitis
    • History of Total Shoulder Arthroplasty
  • Relative
    • Can be treated with less invasive means
    • Tendon tear or rupture
    • Hyperglycemia or poorly controlled diabetes
    • Lack of symptom improvement with previous injection


Subacromial bursa injection using the posterior approach[4]
a) Scheme and (b) ultrasound image of subacromial bursa injection. The needle (arrows) is inserted within the bursa, filled with hyperechoic material (arrowheads) representing steroid solution. A, acromion; H, humerus; S, supraspinatus tendon.[5]
Normal subacrommial space and bursa in long axis.
Probe position in coronal plane for long-axis, in-plane approach[6]
Ultrasound showing long-axis, in-plane approach with needle in the distended subacromial bursa[6]


  • Sterile including chloraprep, chlorhexadine, iodine
  • Gloves
  • Needle: typically 21-25 gauge, 1.5 inch
  • Syringe: 5-10 mL
  • Gauze
  • Ethyl Chloride
  • Bandage
  • Injectate
    • Local anesthetic
    • Corticosteroid

Palpation Guided: Posterior Approach

  • Preferred technique by most physicians
  • Patient Position
    • The patient seated, hands placed in the lap with elbows flexed
  • Landmarks
    • Palpate the lateral and posterior aspects of the acromion, identifying the posterolateral corner
    • Measure approximately 1 cm below the corner as your point of entry, marking the skin
  • Needle Approach
    • Lateral to Medial
    • Insert the needle with needle tip directed towards coracoid process or opposite nipple
  • Pearls and Pitfalls
    • If a bony stucture is hit, pull needle out and redirect cranially or caudally
    • Injectate should flow freely

Palpation Guided: Lateral Approach

  • Favored by some as it is less likely to inject into the rotator cuff tendon
  • Patient Position
    • The patient seated, hands placed in the lap with elbows flexed
  • Landmarks
    • Identify lateral edge of the acromion is located, mark midpoint marked
    • Injection point of entry is 1 to 1.5 inches (about 2.5 to 4 cm) below the marked midpoint
    • Angle of entry: parallel the patient's own acromial angle (averaging 50 to 65 degrees)
    • Depth varies between 1.5 inches and 3.5 inches, depending on body habitus.
  • Needle Approach
    • Lateral to medial
    • Advanced needle through the subcutaneous tissue, deltoid muscle until the subtle resistance of the deep deltoid fascia is encountered
    • If firm or hard tissue resistance is encountered, withdrawn needle about 0.5 inch, redirected 5 to 10 degrees either up or down
    • May feel "popping" sensation when the subacromial bursa is entered.
    • The injectate should flow freely with little effort placed on the syringe

Pearls and Pitfalls

    • Pearl: apply traction to the flexed elbow to open the subacromial space
    • If high injection pressure is encountered, first try rotating the syringe 180 degrees.

Ultrasound Findings

  • General
    • Use high resolution linear array transducer
  • Bursa
    • Normally thin, hypoechoic structure approximately 1 mm in thickness
    • Located between subdeltoid fat plane and superficial to the rotator cuff
    • Normal: bursa is collapsed barely visible
    • Bursitis: hypoechoic fluid collection distening the bursal walls
    • Chronic bursopathy: thickened, hypoechoic bursal wall with or without effusion
  • Common ultrasound findings
    • Enlargement or distension of the bursa
    • Thickened, filled with soft tissue material
    • Inflamed synovium
    • Hyperemia with power doppler
  • Can evaluate dynamically as well

Ultrasound Guided: Long Axis, In Plane

  • Patient Position
    • Seated, lateral decubitus or supine
    • Arm resting at side
  • Transducer Position
    • Coronal oblique or sagittal plane, optimizing bursal view
    • Identify the subacromial bursa in long axis
  • Needle Approach
    • In Plane
    • Lateral to Medial
  • Pearls and Pitfalls
    • Normal bursa is thin, nearly impercetible
    • Injectate may flow quickly into the dependent aspect of the bursa
    • avoid piercing the bursa more than once so that steroid does not leak out of the bursa


  • No major restrictions in most cases
  • Can augment with ice, NSAIDS


  • Skin: Subcutaneus fat atrophy, skin atrophy, skin depigmentation
  • Painful local reaction
  • Infection
  • Hyperglycmia
  • Tendon, nerve or blood vessel injury

See Also


  1. Image courtesy of www.sportsinjurybulletin.com, "Subacromial-subdeltoid bursitis: Shoulder pain isn’t always the rotator cuff"
  2. Park, Jin-Young, et al. "Blind subacromial injection from the anterolateral approach: the ballooning sign." Journal of shoulder and elbow surgery 19.7 (2010): 1070-1075.
  3. Case courtesy of Maulik S Patel, Radiopaedia.org, rID: 23074
  4. Image courtesy of emrap.org, "Subacromial Bursa Injection for Impingement Syndrome"
  5. Messina, Carmelo, et al. "Ultrasound-guided interventional procedures around the shoulder." The British journal of radiology 89.1057 (2016): 20150372.
  6. 6.0 6.1 Malanga, Gerard, and Kenneth Mautner. Atlas of ultrasound-guided musculoskeletal injections. McGraw-Hill, 2014.
Created by:
Jesse Fodero on 10 July 2019 19:07:10
Last edited:
23 March 2023 10:27:48