Osteoarthritis
Osteoarthritis is a chronic progressive joint disorder of cartilage and subchondral bone degradation with low-grade synovitis, diagnosed clinically from age, activity-related pain, and exam findings, and managed with exercise, weight loss, topical or oral NSAIDs, and joint replacement for refractory disease.
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What this article covers
- Overview
Chronic progressive joint disease of maladaptive repair: osteoarthritis (OA) is a disorder of cartilage and meniscal degradation, subchondral bone change (bone marrow lesions, sclerosis), and…
- Epidemiology
Affects approximately 30 million US adults and is the most common form of arthritis worldwide.
- Risk factors
Obesity, the single most important modifiable risk factor, especially for knee OA; increased body mass also raises hand OA risk, suggesting a systemic metabolic/inflammatory contribution beyond mechanical load.
- Pathophysiology
Imbalanced anabolic and catabolic joint tissue signaling produces aberrant chondrocyte repair responses rather than passive mechanical wear.
- Clinical features
Insidious-onset joint pain exacerbated by activity and relieved by rest, the most common and hallmark symptom, becoming more persistent and severe over years.
- Differential diagnosis
Rheumatoid arthritis: symmetric small-joint synovitis, morning stiffness over 1 hour, spares the DIP joints, elevated inflammatory markers, and rheumatoid factor/anti-cyclic citrullinated peptide…
- Diagnosis
OA is a clinical diagnosis established from the combination of age older than 50-55 years, activity-related pain relieved by rest, morning stiffness under 30 minutes, and exam findings of joint-line…
- Management
First, start nonpharmacologic therapy for every patient regardless of joint involved: patient education, a supervised exercise program (walking, strengthening, neuromuscular training, or aquatic…
- Complications
Progressive functional impairment and disability, including reduced mobility, work limitation, and psychosocial isolation.
- Prognosis
Symptoms correlate poorly with radiographic severity: some patients with advanced radiographic change have minimal symptoms and vice versa.
- Prevention
Maintain a healthy body weight: a 5-10% reduction in body weight produces meaningful improvement in knee OA symptoms, with greater benefit at higher percentage loss, since obesity is the single most important modifiable risk factor.
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