Contrast osteoarthritis with rheumatoid arthritis.

If both rheumatoid arthritis and osteoarthritis can lead to end-stage destruction of the joint, why is it important to differentiate between the two?

OA vs RA

Osteoarthritis (OA) and rheumatoid arthritis (RA) can present with very similar symptoms, especially from the perspective of the patient. They are, however, very different disease processes with unique management strategies and prognoses. The table below seeks to compare and contrast OA and RA.

Table legend of abbreviations: CMC - carpometacarpal; DIP - distal interphalangeal; MCP - metacarpophalangeal; PIP - proximal interphalangeal; MTP - metatarsophalangeal; RF - rheumatoid factor; CCP - cyclic citrullinated peptide; ESR - erythrocyte sedimentation rate; CRP - C-reactive protein

Why the distinction of OA vs RA matters

Both OA and RA can result in end-stage destruction of the involved joints, causing significant disability in affected patients. Despite this similar endpoint, it is critical to differentiate these two diseases for the following reasons:

1. Whereas the treatment of OA is palliative and targets presenting symptoms, RA treatment is truly “disease modifying;” that is, treatment may be enduringly beneficial, beyond mere symptom relief.
2. RA is a potentially systemic disorder that can affect a variety of other organs including the heart and lungs (manifesting as myocarditis or parenchymal lung disease, respectively). Treatment of RA might be initiated for the joint symptoms but may prevent systemic organ involvement.