What is osteoarthritis?
Osteoarthritis is a degenerative joint disease resulting from the progressive wear and tear of cartilage, the protective tissue covering the ends of bones in joints. It is the most common joint disease, primarily affecting people over 50. 
Contrary to popular belief, osteoarthritis does not only affect cartilage; it involves all the structures of the joint, including the underlying bone, ligaments, synovial membrane, and surrounding muscles.
The most frequently affected joints are:
- Knees (gonarthrosis)
- Hips (coxarthrosis)
- Hands and fingers
- Spine (rachis)
- Shoulders
Osteoarthritis is favored by several factors: age, repeated efforts, joint trauma, overweight, genetic predispositions, and certain anatomical abnormalities.
What are the first signs? And eventually, the symptoms?
The first signs of osteoarthritis:
Symptoms generally begin gradually and insidiously:
1. Mechanical pain
- This is the most characteristic symptom
- Pain appears or worsens when using the joint (walking, standing, climbing stairs, carrying loads)
- Relieved by rest
- Absent or minimal at rest and at night (unlike arthritis)
2. Morning stiffness
- Sensation of "rustiness" upon waking or after a period of immobility
- This stiffness is usually short-lived (less than 30 minutes)
- Gradually decreases with movement
3. Joint creaking
- Joint noises during movements (crepitations)
- Sensation of rubbing or "grinding"
Long-term symptoms (advanced osteoarthritis):
As osteoarthritis progresses, symptoms intensify:
1. More frequent and intense pain
- Pain present even at rest in advanced stages
- Night pain that can disrupt sleep
- Pain becoming chronic
2. Progressive limitation of movement
- Decreased joint range of motion
- Difficulty performing certain daily gestures
- Loss of flexibility
3. Joint deformity
- Appearance of nodules (bone growths called osteophytes)
- Joint swelling
- Visible deformity, especially in the fingers
4. Impact on quality of life
- Significant functional impairment
- Difficulties in daily activities
- Risk of loss of autonomy in severe cases
What is the difference between osteoarthritis and arthritis?
Although these two conditions affect the joints and cause pain, they are fundamentally different:
| Criterion | Osteoarthritis | Arthritis |
|---|---|---|
| Nature | Degenerative disease (mechanical wear) | Inflammatory disease |
| Origin | Cartilage wear related to age, trauma, or repeated efforts | Inflammatory reaction often of autoimmune or infectious origin |
| Type of pain | Mechanical pain: appears with effort, relieved by rest | Inflammatory pain: present at rest, often at night |
| Morning stiffness | Short duration (< 30 minutes) | Prolonged (> 30 minutes, sometimes several hours) |
| Swelling | Infrequent, moderate | Frequent, with local heat and redness |
| Age of onset | Generally after 50 years old | Can occur at any age, even in young adults |
| Affected joints | Often begins in a single joint, asymmetrically | Often affects several joints symmetrically |
| Evolution | Progressive and slow | Can evolve in inflammatory flares |
Key points to remember:
- Osteoarthritis is "wear and tear" of the cartilage, like tire wear.
- Arthritis is an active inflammation of the joint, often due to an immune system imbalance.
- Osteoarthritis can nevertheless present occasional inflammatory phases.
- It is possible to suffer from both pathologies simultaneously.
