OrthoNet

Fibrous Dysplasia

- dysplastic disorder of bone characterized by presence of trabeculae of immature bone at 1 or many sites
- represents disordered bone maturation & often results in progressive bony deformity that may be associated with pathological #
- presents in 2nd or 3rd decade
- Albright’s syndrome - polyostotic variant associated with precocious puberty & café-au-lait spots

Signs & Symptoms:
- pain with tenderness & swelling at the site of the lesion (monostotic vs polyostotic)

Xrays:
- ‘ground glass’ appearance
- well-defined marginated lesion with rim of sclerotic bone
- expansion, endosteal scalloping & deformity of affected bone
- ‘shepherd’s crook’ - classic deformity of prox. femur arising from bowing of bone & many pathologic #s

Histology:
- collagenous matrix containing proliferating fibroblasts in haphazard pattern
- paucity of osteoblasts surrounding bony trabeculae à distinguishes it from osteofibrous dysplasia

Treatment:
- non-weightbearing skeleton - observation
- weightbearing skeleton - internal fixation & bone grafting
- sarcomatous transformation - occ in polyostotic form