rheumatoid arthritis - joint manifestations CHORUS

Description: * early signs:
* fusiform periarticular soft tissue swelling (result of effusion)
* regional osteoporosis (disuse and local hyperemia)
* widened joint space
* marginal + central bone erosion (base of 4th proximal phalanx most common)
* change in ulnar styloid and distal radioulnar joint
* atlantoaxial dislocation
* giant synovial cysts
* late signs:
* flexion/extension contractures with ulnar subluxation/dislocation
* destruction/fusion of joints
* elevation of humeral heads (tear/atrophy of rotator cuff)
* resorption of distal clavicle
* erosion of superior margins of posterior portions of 3-5th ribs
* destruction/narrowing of disc spaces
* destruction of zygapophyseal joints without osteophyte formation
* resorption of spinous process
* protrusio acetabuli (from osteoporosis)