- Osteoarthritis is a complex joint disease, not just wear and tear, and it’s not an inevitable part of aging.
- Exercise is the most effective treatment for osteoarthritis, offering benefits similar to medication without side effects.
- While cartilage damage is initially painless, your osteoarthritis pain comes from surrounding joint structures.
- Osteoarthritis affects the entire joint, including bone, ligaments, and muscles, not just the cartilage itself.
Table of Contents
- What is Osteoarthritis?
- Articular Cartilage
- The Osteoarthritic Process
- Most Affected Joints
- Causes and Risk Factors
- Non-Modifiable Factors
- Modifiable Factors
- Symptoms
- Pain
- Stiffness
- Crepitus
- Swelling
- Functional Limitation
- Deformity
- Diagnosis
- Clinical Examination
- Imaging Diagnostics
- Blood Tests
- Treatment
- The Three Pillars (Recommended by ALL Guidelines)
- Medications
- Physiotherapy
- Surgery
- General Exercises for Osteoarthritis
- General Principles
- Prevention
- Frequently Asked Questions (FAQ)
- Can osteoarthritis be cured?
- Does exercise worsen osteoarthritis?
- What is the difference between osteoarthritis and arthritis?
- Do cold and humidity worsen osteoarthritis?
- Is osteoarthritis hereditary?
- When is it time for a joint replacement?
- Do joint supplements work?
- Related articles
Osteoarthritis
Osteoarthritis (OA) is the most common joint disease worldwide and the leading cause of disability in the elderly population. It affects over 300 million people globally, and its prevalence continues to rise due to an aging population and increasing obesity rates.
Osteoarthritis is characterized by the progressive deterioration of articular cartilage — the smooth, resilient tissue that covers the ends of bones within joints, allowing for friction-free movement. When cartilage wears down, bones begin to rub against each other, causing pain, stiffness, swelling, and progressive limitation of movement.
Contrary to popular belief, osteoarthritis is not an inevitable consequence of aging and is not a passive “wear and tear” disease. It is an active process in which mechanical, metabolic, and inflammatory factors interact to alter the balance between cartilage destruction and repair. This modern understanding opens the door to effective preventive and therapeutic strategies.
Exercise is the treatment with the best scientific evidence for osteoarthritis, with effects comparable to anti-inflammatory drugs but without side effects.
What is Osteoarthritis?
Articular Cartilage
Articular (or hyaline) cartilage is an avascular tissue (without blood vessels) composed of:
- Water (65-80%): provides elasticity and shock-absorbing capacity
- Type II Collagen: provides tensile strength
- Proteoglycans: retain water and resist compression
- Chondrocytes: the cells that produce and maintain the cartilage matrix
Cartilage has no blood vessels or nerve endings — which is why cartilage damage is initially painless. Osteoarthritis pain originates from surrounding structures: subchondral bone, synovial membrane, joint capsule, tendons, and muscles.
The Osteoarthritic Process
Osteoarthritis is not simply “wear and tear” of cartilage. It is a complex process involving the entire joint:
- Cartilage: thinning, fibrillation, erosion leading to bone exposure
- Subchondral bone: thickening (sclerosis) and cyst formation
- Osteophytes: formation of “bone spurs” at the joint margins — the bone’s attempt to increase the load-bearing surface
- Synovial membrane: intermittent inflammation (synovitis) with production of inflammatory mediators
- Joint capsule: thickening and retraction, contributing to stiffness
- Muscles: weakness due to reflex inhibition from pain and disuse
Most Affected Joints
| Joint | Characteristics |
|---|---|
| Knee (gonarthrosis) | Most frequent, strongly correlated with overweight |
| Hip (coxarthrosis) | Most disabling, main cause of prosthesis |
| Hands and fingers | Most hereditary, mainly affects women |
| Spine (spondyloarthrosis) | Almost universal after 60 years of age |
| Shoulder (omarthrosis) | Less frequent, often secondary to rotator cuff injuries |
| Foot (first metatarsophalangeal) | Hallux rigidus |
Causes and Risk Factors
Non-Modifiable Factors
- Age: the most important factor — prevalence progressively increases after 50 years of age
- Female sex: women are affected more frequently, especially after menopause (role of estrogens in cartilage protection)
- Genetics: a familial predisposition is documented, especially for hand osteoarthritis
- Ethnicity: differences in prevalence among different populations
Modifiable Factors
- Overweight and obesity: the most important modifiable risk factor for knee and hip. Every excess kg increases the load on the knee by 3-4 kg during walking. Obesity also contributes to hand osteoarthritis (non-weight-bearing) through metabolic mechanisms
- Joint trauma: fractures, sprains, meniscal and ligamentous injuries increase the risk of osteoarthritis by 4-6 times in the long term
- Mechanical overload: heavy labor (lifting, kneeling positions), high-impact sports
- Muscle weakness: weakness of periarticular muscles reduces cartilage protection
- Malalignment: varus, valgus, dysplasia — concentrate load on restricted portions of cartilage
- Metabolic diseases: diabetes, gout, hemochromatosis
Symptoms
Pain
- Mechanical pain: worsens with activity and improves with rest (unlike inflammatory pain of arthritis which worsens with rest)
- Start-up pain: pain in the first movements after a period of inactivity, which improves after a few minutes
- Progression: initially, pain occurs only after intense exertion, then with moderate activities, finally at rest and at night (in advanced stages)
Stiffness
- Morning stiffness: less than 30 minutes (unlike rheumatoid arthritis, where it exceeds 60 minutes)
- Stiffness after inactivity (gelling): joints “lock up” after periods of immobility
Crepitus
Cracking, crunching, and a “gritty” sensation perceived within the joint during movement.
Swelling
Intermittent joint effusion, with swelling and warmth, especially after activity.
Functional Limitation
Progressive reduction in range of motion and functional capacity: difficulty walking, climbing stairs, dressing, grasping objects.
Deformity
In advanced stages: joint deformities (knee varus/valgus, Heberden’s nodes in the hands, subluxation of the thumb base).
Diagnosis
Clinical Examination
The diagnosis of osteoarthritis is predominantly clinical:
- Mechanical pain (worsens with activity)
- Morning stiffness < 30 minutes
- Crepitus with movement
- Limitation of mobility
- Joint deformity and/or palpable osteophytes
Imaging Diagnostics
- Weight-bearing X-ray: the first-choice examination. Highlights classic signs:
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- Joint space narrowing
- Osteophytes (bone spurs)
- Subchondral sclerosis (bone thickening)
- Subchondral cysts
- MRI: indicated to assess the condition of cartilage, menisci, and ligaments. Not necessary for osteoarthritis diagnosis but useful to rule out other pathologies
- Ultrasound: can show synovitis, effusion, osteophytes
Blood Tests
Blood tests are normal in osteoarthritis. They are only used to rule out other conditions (rheumatoid arthritis: rheumatoid factor, anti-CCP; gout: uric acid).
Treatment
The Three Pillars (Recommended by ALL Guidelines)
1. Exercise
The treatment with the best scientific evidence. Exercise:
- Reduces pain by 30-50% (effect comparable to NSAIDs)
- Improves functionality and quality of life
- Strengthens periarticular muscles that protect cartilage
- Maintains joint mobility
- Improves mood and sleep
- Has systemic anti-inflammatory effects
- Has no side effects
Recommended program:
- Muscle strengthening: 2-3 times a week (quadriceps for the knee, glutes for the hip, etc.)
- Aerobic activity: 30 minutes, 5 times a week (walking, swimming, cycling)
- Flexibility: daily stretching
- Balance and proprioception: for fall prevention
2. Weight Management
Losing 5-10% of body weight is sufficient for a clinically significant improvement. The combination of diet and exercise is the most effective strategy.
3. Education
Understanding the disease, self-management strategies, the importance of exercise, and when to seek help.
Medications
- Paracetamol (Acetaminophen): first-choice analgesic for mild pain
- Topical NSAIDs: diclofenac gel — recommended as first-line pharmacological treatment for knee and hands
- Oral NSAIDs: for flare-ups, for limited periods (gastrointestinal and cardiovascular risk)
- Corticosteroid injections: effective for flare-ups with effusion
- Hyaluronic acid injections: viscosupplementation — moderate evidence, more effective in the knee
- Duloxetine: antidepressant indicated for chronic osteoarthritic pain with a central sensitization component
Physiotherapy
- Personalized therapeutic exercises: the core of the treatment
- Manual therapy: joint mobilization
- Physical therapies: TENS, ultrasound, heat
- Therapeutic education: self-management, joint protection
- Assistive devices: canes, orthoses, insoles
Surgery
Indicated when conservative treatment fails after at least 3-6 months:
- Knee replacement: satisfaction >85%
- Hip replacement: satisfaction >95%
- Shoulder replacement: growing in popularity, good results
- Arthroscopy: limited role in osteoarthritis — evidence does not support arthroscopic “lavage”
General Exercises for Osteoarthritis
Osteoarthritis is a degenerative joint disease characterized by progressive cartilage loss, bone changes, and inflammation affecting weight-bearing and mobile joints, presenting with mechanical pain, stiffness, and functional limitation. The program should be adapted to the joint involved. For specific exercises, consult the dedicated guides: knee osteoarthritis, hip osteoarthritis, hand osteoarthritis, cervical osteoarthritis, shoulder osteoarthritis.
General Principles
Low-impact aerobic activity
[IMAGE: Three activities shown side-by-side: on the left a person walking briskly, in the center a person in a pool swimming freestyle, on the right a person on an exercise bike. All shown in profile with correct posture. The three activities represent the recommended aerobic options for osteoarthritis.]
Muscle strengthening with resistance band
[IMAGE: Person sitting on a chair performing a knee extension against the resistance of a therapeutic band tied to the chair leg and ankle. The back is straight. Side view with detail of the band and extension angle.]
Muscle stretching
[IMAGE: Person standing in front of a wall performing a calf stretch: one leg back with a straight knee and heel on the ground, the other leg forward with a bent knee. Hands are resting on the wall. Side view.]
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Balance exercise
[IMAGE: Person standing on one leg next to a chair (for safety). The other leg is slightly lifted off the floor. Arms are open for balance. Front view.]
Prevention
- Maintain a healthy weight: overweight is the most important modifiable risk factor
- Regular physical activity: keeps cartilage nourished (cartilage nourishes itself through movement — cyclic loading “squeezes” and “absorbs” nutrients like a sponge)
- Muscle strengthening: strong muscles protect joints
- Avoid trauma: adequate warm-up, correct sports technique
- Treat structural abnormalities: malalignment, dysplasia, meniscal injuries
- Do not smoke: smoking compromises cartilage repair
- Balanced diet: rich in omega-3s, vegetables, fruits — anti-inflammatory effects
Frequently Asked Questions (FAQ)
Osteoarthritis is not “curable” in the sense of being reversible: lost cartilage does not regenerate spontaneously. However, symptoms can be managed very effectively with exercise, physiotherapy, weight management, and medication. In advanced cases, joint replacement offers excellent results. The goal of treatment is to reduce pain, maintain functionality, and improve quality of life.
No, it’s the opposite. Physical exercise is the most effective treatment for osteoarthritis, with effects comparable to medications. Cartilage needs movement to nourish itself (it nourishes itself by diffusion through cyclic loading). Inactivity worsens osteoarthritis because it weakens muscles, stiffens joints, and deprives cartilage of its “nutrition.”
Osteoarthritis is a degenerative disease (cartilage wear), while arthritis is an inflammatory disease (the immune system attacks the joints). Osteoarthritis worsens with activity and improves with rest; rheumatoid arthritis worsens with rest (morning stiffness >60 minutes) and improves with movement.
Many people with osteoarthritis report worsening symptoms with cold and humidity. The mechanism is not fully understood (possible increase in synovial fluid viscosity, atmospheric pressure changes). Local heat (compresses, hot shower) is an effective remedy.
Yes, there is a genetic component, especially for hand osteoarthritis (Heberden’s nodes). However, genetics is not destiny: lifestyle (weight, exercise, trauma prevention) can significantly modify the course of the disease even in those with a family predisposition.
Joint replacement is indicated when pain and functional limitation significantly impair quality of life despite at least 3-6 months of adequate conservative treatment. There is no “mandatory” radiographic grade for surgery: the decision is based on symptoms and quality of life, not on X-rays. Some people with radiographically severe osteoarthritis have few symptoms, and vice versa.
Glucosamine and chondroitin, the most studied, have conflicting evidence. High-quality studies do not show a significant benefit superior to placebo. They are not harmful but also not proven effective. OARSI and ACR guidelines neither recommend nor advise against them. Your doctor or physical therapist will advise based on your individual situation.
Frequently Asked Questions
Can osteoarthritis be cured?
Osteoarthritis is a chronic, progressive condition for which there is currently no cure that fully reverses the joint damage. However, various treatments focus on managing symptoms, improving function, and slowing disease progression. Early intervention and consistent management strategies are crucial for maintaining quality of life.
Does exercise worsen osteoarthritis?
No, appropriate exercise is generally beneficial for osteoarthritis and does not worsen the condition. Regular physical activity, guided by a physical therapist, helps strengthen muscles, improve joint mobility, and reduce pain. It is a cornerstone of osteoarthritis management.
What is the difference between osteoarthritis and arthritis?
Arthritis is a general term encompassing over 100 different conditions that cause joint inflammation. Osteoarthritis is the most common form of arthritis, characterized by the progressive deterioration of articular cartilage and changes in the entire joint structure. Other forms of arthritis, such as rheumatoid arthritis, are autoimmune diseases with different underlying causes.
When is it time for a joint replacement?
Joint replacement surgery is typically considered when conservative treatments, such as physical therapy, medication, and lifestyle modifications, no longer effectively manage pain or improve functional limitations. The decision is made in consultation with a medical professional, weighing the severity of symptoms, impact on daily life, and overall health status.
Sources and Scientific References
- Bennell K (2013). Physiotherapy management of hip osteoarthritis. J Physiother. 59:145-57. DOI | PubMed
- Page CJ et al. (2011). Physiotherapy management of knee osteoarthritis. Int J Rheum Dis. 14:145-51. DOI | PubMed
- Tore NG et al. (2023). The quality of physiotherapy and rehabilitation program and the effect of telerehabilitation on patients with knee osteoarthritis. Clin Rheumatol. 42:903-915. DOI | PubMed
- Michael JW et al. (2010). The epidemiology, etiology, diagnosis, and treatment of osteoarthritis of the knee. Dtsch Arztebl Int. 107:152-62. DOI | PubMed
- Atalay SG et al. (2021). The Effect of Acupuncture and Physiotherapy on Patients with Knee Osteoarthritis: A Randomized Controlled Study. Pain Physician. 24:E269-E278. PubMed