Osteoarthritis (OA)

Occurs >50 years old, usually becomes symptomatic much later
  • Also called “Degenerative Joint Disease” (DJD)
Insidious onset (usually)
  • Typically:  No morning stiffness (<30 min. at most)
  • Inflammatory OA can mimic RA (acute; morning stiffness)
Joints:
  • Knees
  • Hips
  • Fingers: PIPs & DIPs, rarely MCPs
  • Hand (where 1st Metacarpal meets wrist)
  • Spine
 Secondary OA can occur in joints damaged by other diseases
  • Suspect if atypical joints (shoulder, elbow, wrist, ankle)
  • Suspect if onset at youngish age
 Diagnose by X-Ray:  Joint-space narrowing
  • No findings suggestive of Pseudogout (“CPPD”)
  • No hand erosions as in RA
Distinguish Inflammatory OA from RA in Hand by:
  • ESR / CRP usually normal in OA
  • DIPs & PIPs prominently involved (in RA: MCPs & PIPs, not DIPs)
  • No ulnar deviation as in RA
  • XR: no erosions in OA [do occur rarely in DIPs]
  • XR:  Heberden’s Nodes (DIPs) diagnostic

Heberden’s Nodes