05/01/2026
(OA)
Osteoarthritis is the most common form of arthritis and a chronic, degenerative joint disease characterized by the gradual breakdown of articular cartilage, changes in subchondral bone, and inflammation of surrounding joint tissues, leading to pain, stiffness, and reduced mobility.
Osteoarthritis is a progressive disorder of synovial joints in which cartilage degeneration exceeds repair, resulting in joint space narrowing, osteophyte formation, and functional impairment.
Epidemiology
Most common joint disease worldwide
Prevalence increases with age
More common in women, especially after menopause
Frequently affects weight-bearing joints
Commonly Affected Joints
Knee (most common)
Hip
Spine (cervical & lumbar)
Hands (DIP, PIP joints, thumb base)
Feet
Etiology (Causes)
Primary (Idiopathic) OA
Age-related cartilage wear
Genetic predisposition
Secondary OA
Joint trauma or fractures
Obesity
Congenital joint abnormalities
Metabolic disorders (e.g., hemochromatosis)
Repeated occupational stress
Pathophysiology
Loss of proteoglycans and collagen from cartilage
Cartilage becomes thin, cracked, and eroded
Increased friction → pain and stiffness
Subchondral bone sclerosis
Formation of osteophytes (bone spurs)
Mild synovial inflammation
Clinical Features
Symptoms
Joint pain worsens with activity, relieved by rest
Morning stiffness (< 30 minutes)
Reduced range of motion
Crepitus (grating sensation)
Joint swelling (usually mild)
Functional limitation
Signs
Bony enlargement
Joint tenderness
Restricted movement
Deformities in advanced stages
Special Hand Findings
Heberden’s nodes – DIP joints
Bouchard’s nodes – PIP joints
Diagnosis
Clinical Diagnosis
Based on symptoms and physical examination
Radiological Findings (X-ray)
Joint space narrowing
Osteophytes
Subchondral sclerosis
Subchondral cysts
(Mnemonic: LOSS)
Laboratory Tests
Usually normal
Used to rule out inflammatory arthritis
Differential Diagnosis
Rheumatoid arthritis
Gout
Pseudogout
Septic arthritis
Avascular necrosis
Management
Non-Pharmacological (First Line)
Weight reduction
Physiotherapy & exercise
Joint protection techniques
Heat/cold therapy
Walking aids if needed
Pharmacological
Paracetamol (first line)
NSAIDs (topical/oral)
COX-2 inhibitors
Intra-articular corticosteroid injections
Viscosupplementation (hyaluronic acid)
Surgical Management
Indicated in severe OA with disability
Joint replacement (e.g., total knee replacement)
Osteotomy (selected cases)
Complications
Chronic pain
Disability
Joint deformity
Reduced quality of life
Prognosis
Slowly progressive
Cannot be cured, but symptoms can be effectively controlled
Early intervention improves outcomes
Prevention
Maintain healthy weight
Regular low-impact exercise
Avoid repetitive joint stress
Early treatment of joint injuries
Osteoarthritis is a degenerative joint disease marked by cartilage loss, bone changes, and chronic joint pain leading to reduced mobility.