DDx
1. Congenital
Rare
- anterior or posterior
- lateral uncommon
2. Acquired
- unrecognised Monteggia
- osteochondroma
- enchondroma
3. Skeletal Dysplasia
- OI - ulna deformity
- Achondroplasia
- Down's Syndrome
- Nail-Patella
- Klinefelter's
- Marfan's
- Hereditary Multiple Exostosis
- Ehlers Danlos
- Larsens
Congenital
History
Familial
Other congenital problems
Xray
Convex radial head
Hypoplastic capitellum
Long radius compared with ulna
Management
No treatment (reconstructions fail)
- most congenital dislocations are asymptomatic
- good function and ROM
- excise radial head as adult if painful