Skeletal fluorosis is a chronic metabolic bone disease caused by ingestion of large amounts of fluoride through either water or food in geographic areas where high levels of fluoride occur naturally.
Described features include:
- increased bone density: osteosclerosis
- osteopaenia/osteoporosis 4,6
- trabecular blurring or haziness
- compact bone thickening
- periosteal bone formation and
- ossification of the attachments of tendons, ligaments, and muscles
- interosseous membrane calcification 1
- ossification of the posterior longitudinal ligament 2
Involvement of the axial skeleton is characteristic, and changes are most marked in the spine, pelvis and ribs.
In early fluorosis, the first changes are bone deposition and thickening at the junctions of trabeculae. This is seen as sandlike, granular, or particle like bone structure on radiographs.
In more advanced fluorosis, the trabeculae are more generally thickened because of new bone formation on the trabecular surface. At this stage, radiographs show thickening and condensation of trabeculae, with coarse reticulam or woven bone striations.
If the trabeculae are fused, focal round densities are seen in the medullary bone.
Osteopaenia (less common) also may occur in fluorosis, especially in younger patients at an earlier stage 6.
Calcification of the sacrotuberous ligament is considered a characteristic feature.
For diffuse skeletal sclerosis on imaging, consider:
Metabolic bone disease
- bone mineralisation
- pituitary gland-related
- thyroid gland-related
- osteosclerosis (differential diagnosis | mnemonic)
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- 6. Lian ZC, Wu EH. Osteoporosis-an early radiographic sign of endemic fluorosis. Skeletal Radiol. 1986;15 (5): 350-3. Pubmed citation