Avascular Necrosis of the Humeral Head

Question 1

What are common causes of atraumatic AVN of the humeral head?

Answer 1

ASEPTIC
Alcohol, AIDS
Steroids (most common), Sickle, SLE
Erlenmeyer flask (Gaucher’s)
Pancreatitis
Trauma
Idiopathic/ Infection
Caisson’s (the bends)

Question 2

What is the rate of AVN for 3- and 4-part proximal humerus fractures?

Answer 2

1) four-part fracture-dislocations approach 100% AVN
2) displaced four-part fractures ~45% AVN
3) valgus impacted four-part ~11% AVN
4) three-part ~14% AVN

Question 3

What is the classification for humeral head AVN? Treatment?

Answer 3

Cruess
Stage I: normal x-ray, MRI abnormal 
Stage II: sclerosis, mottled, osteopenia
Stage III: crescent sign, subchondral fx
Stage IV: collapse and flattening
Stage V: degenerative changes extend to glenoid

Stages I and II- core decompression
Stage III- resurfacing or hemiarthroplasty
Stage IV- hemiarthroplasty
Stage V- total shoulder arthroplasty