What are the key clinical features that differentiate osteoarthritis f

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Key clinical features differentiating osteoarthritis (OA) from rheumatoid arthritis (RA) in primary care:

Age of onset: OA typically affects people aged 45 years and over, whereas RA can occur from age 16 onwards.
Joint involvement pattern: OA usually involves larger weight-bearing joints such as hips, knees, and shoulders, and is often localized to a few joints. RA commonly affects multiple joints, especially the small joints of the hands and feet, with symmetrical involvement.
Morning stiffness: OA presents with either no morning stiffness or stiffness lasting less than 30 minutes. RA is characterized by prolonged morning stiffness lasting more than 30 minutes.
Inflammatory signs: RA shows signs of persistent synovitis, joint swelling, tenderness, and loss of function, often with systemic symptoms like fatigue. OA typically lacks significant inflammatory signs and systemic symptoms.
Progression and deformity: RA can cause progressive joint deformity and erosions visible on X-ray, while OA leads to joint space narrowing and osteophyte formation without erosions.
Response to treatment: RA requires early specialist referral and disease-modifying treatments, whereas OA management focuses on symptom relief, exercise, and weight management.

These clinical distinctions guide diagnosis and management in primary care settings.

References: ,,

What are the key clinical features that differentiate osteoarthritis from rheumatoid arthritis in a primary care setting?