Mega os trigonum in progressive pseudorheumatoid dysplasia

Pediatr Radiol. 2002 Jan;32(1):46-8. doi: 10.1007/s00247-001-0576-4. Epub 2001 Nov 8.


Background: Progressive pseudorheumatoid dysplasia (PPRD), a noninflammatory condition, needs to be differentiated diagnostically from juvenile rheumatoid arthritis (JRA).

Objective: Demonstration of an unusually large and often early-appearing os trigonum helps distinguish PPRD from JRA.

Materials and methods: Ankle images in four children with PPRD were reviewed.

Results: The os trigonum was abnormally enlarged in all PPRD subjects and was shown to have appeared or fused earlier than normal in two subjects.

Conclusion: A large and early os trigonum ossification helps differentiate PPRD from JRA.

MeSH terms

  • Arthritis, Juvenile / diagnostic imaging*
  • Child
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Osteochondrodysplasias / diagnostic imaging*
  • Radiography
  • Talus / diagnostic imaging*
  • Talus / pathology*