Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Apr 12 2022

Avascular Necrosis of the Shoulder

Images 5 avn.jpg 2 avn.jpg 3 avn.jpg mri.jpg
  • summary
    • Avascular necrosis of the shoulder is a condition characterized by interruption of blood supply to the humeral head which may lead to humeral head sclerosis and subchondral collapse. 
    • Diagnosis is made radiographically with orthogonal radiographs of the shoulder in moderate/late disease. MRI may be needed for detection of early or subclinical avascular necrosis.
    • Treatment may be observation for very early and minimally symptomatic disease. Surgical management is indicated for progressive symptoms in the setting of moderate to advanced disease.
  • Etiology
    • Pathophysiology
      • pathoanatomy
        • decreased blood supply to humeral head leading to death of cells in bony matrix.
        • bone is resorbed and remodeled, causing subchondral bone collapse and may lead to joint incongruity and arthritic changes
      • etiology similar to hip
        • Remember ASEPTIC mneumonic
          • Alcohol, AIDS
          • Steroids (most common), Sickle, SLE
          • Erlenmeyer flask (Gaucher’s)
          • Pancreatitis
          • Trauma
          • Idiopathic/ Infection
          • Caisson’s (the bends)
        • may be atraumatic
        • posttraumatic
          • four-part fracture-dislocations approach 100% AVN
          • displaced four-part fractures ~45% AVN
          • valgus impacted four-part ~11% AVN
          • three-part ~14% AVN
  • Anatomy
    • Blood supply
      • Humeral head
        • ascending branch of anterior humeral circumflex artery and arcuate artery
          • provides blood supply to humeral head
          • vessel runs parallel to lateral aspect of tendon of long head of biceps in the bicipital groove
            • beware not to injure when plating proximal humerus fractures
          • arcuate artery is the interosseous continuation of ascending branch of anterior humeral circumflex artery and penetrates the bone of the humeral head
          • provides 35% of blood supply to humeral head
        • posterior humeral circumflex artery
          • most current literature supports this as providing the main blood supply to humeral head
          • provides 65% of blood supply
  • Classification
      • Cruess Classification (stages)
      • Radiographic findings
      • Treatment
      • StageI
      • Normal x-ray, changes on MRI only
      • Core decompression
      • Stage II
      • Sclerosis (wedged, mottled) Osteopenia
      • Core decompression
      • Stage III
      • Crescent sign indicating a subchondral fracture
      • Resurfacing or hemiarthroplasty
      • Stage IV
      • Flattening and collapse
      • Resurfacing or hemiarthroplasty
      • Stage V
      • Degenerative changes extend to glenoid
      • Total shoulder arthroplasty
  • Presentation
    • Symptoms
      • insidious onset of shoulder pain
        • often without a clear inciting event
      • pain, loss of motion, crepitus, and weakness
    • Physical exam
      • limited range of motion
      • crepitus
      • weakness of the rotator cuff and deltoid muscles
  • Imaging
    • Radiographs
      • recommended views
        • five views of shoulder (shown best in neutral rotation AP)
      • findings
        • no findings on radiograph at onset of disease process
        • osteolytic lesion develops on radiograph demonstrating resorption of subchondral necrosis
          • most common initial site is superior middle portion of humeral head
        • crescent sign demonstrates subchondral collapse
        • may progress to depression of articular surface and consequent arthritic changes.
    • MRI
      • preferred imaging modality
        • ~100% sensitivity in detection
      • will demonstrate edema at the site of subchondral sclerosis
  • Treatment
    • Nonoperative
      • pain medications, activity modification, physical therapy
        • indications
          • first line of treatment
        • technique
          • physical therapy
            • restrict overhead activity and manual labor
    • Operative
      • core decompression + arthroscopy (confirm integrity of cartilage)
        • indications
          • early disease (precollapse Cruess Stage I and II)
      • humeral head resurfacing
        • indications
          • Stage III disease with focal chondral defects, and sufficient remaining epiphyseal bone stock for fixation.
      • hemiarthroplasty
        • indications
          • moderate disease (Cruess Stage III and IV)
      • total shoulder arthroplasty
        • indications
          • advance stage (Cruess V)
  • Prognosis
    • Related to stage of disease
1 of 1
1 of 6
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options