From the case:
Rheumatoid arthritis
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Hitchhiker's thumb and swan-neck deformities of multiple fingers. Subluxation of the metacarpophalangeal joints with telescoping of some digits especially the middle finger. Advanced degeneration of the carpus.
Case Discussion
Radiographic features of rheumatoid arthritis of the hand include:
- periarticular osteoporosis, subluxation, dislocation and erosions
- metacarpophalangeal ulnar deviation
- Boutonniere deformity: hyperextension of DIP, flexion of PIP
- swan-neck deformity: hyperextension of PIP, flexion of DIP
- hitchhiker's thumb
- telescope fingers: shortening of phalanges due to dislocations
- ulnar and radial styloid erosions are common
- wrist instability: ulnar translocation, scapholunate dissociation