DDx-MSK

Question 1

DDx of the underlying etiologies?

Answer 1

AVN: irregular subchondral sclerosis w/subchondral low signal w/patchy surrounding hypodensity, consistent w/edema.

DDx:

• Chronic steroid use: the most common non-traumatic cause!
• EtOH
• Radiation
• Trauma
• Sickle cell

Question 2

DDx?

Answer 2

DDx rugger jersey spine:

1. Renal osteodystrophy: smudgy/fuzzier demarcation w/in the vertebral bodies; look for extraskeletal evidence of chronic renal failure, e.g., nephrectomy, renal xplant or dialysis catheters in the chest.
2. Osteopetrosis: more sharply defined borders w/in the vertebral bodies (see below).
3. Pagets: “picture frame” vertebral body.