Aneurysmal bone cysts
- Can occur at any age. Commonest in 10–30 year olds with the majority arising prior to epiphyseal fusion.
- Any bone may be affected but most commonly occur in long-bone metaphyses, especially the lower limb.
- Aetiology unknown.
- Pain associated with expansile lesions.
- Pathological fractures may occur.
- May be visible or palpable if sufficiently large.
- Well-defined radiolucent cyst, often eccentric within bone. Marked ‘soap-bubble’ expansion may be seen.
- Usually trabeculated with a thin intact cortex (narrow transition zone).
- No periosteal reaction (except when fractured).
- Within the spine, posterior elements are more commonly involved.
- May be mistaken for other cyst-like lesions – see Bone cysts.
- MRI/CT – fluid levels within cyst due to blood sedimentation (in up to 35%).
- Curettage and bone grafting, or substitute grafting.
- If the ABC recurs, then consider bone cement rather than bone graft in the revision procedure.
James R. D. M., Erskine J. H., Rakesh R. M. (2008). Musculoskeletal Radiology. A-Z Musculoskeletal and Trauma Radiology, 1st edition, Cambridge University Press, Cambridge, 1, 1-176.