What is it?

Osteoarthritis is a degeneration of the cartilage without infection or inflammation special. This degeneration leads to destruction more or less rapid cartilage coats the ends of bones. Anatomically, this destruction is accompanied by a proliferation of bone under the cartilage.

Joint disease is the most common. The first symptoms usually appear from 40-50 years, but the disease often starts much earlier in life.

Mechanisms ?

The articular cartilage tissue is not inert: it is the seat of intense activity where production chrondrocytes (cartilage cells) precludes, at least initially, the destruction of these cells. When the phenomena of destruction outweigh the regeneration of cartilage, the cartilage thickness decreases and the joint is altered permanently.

This intense activity of producing new cells occurs at the margin of the joint by producing new growths of bone: bone spurs.

During cartilage destruction, small pieces of cartilage may break off and “float” in the pocket joints: they then trigger outbreaks inflammatory mechanisms that result in hypersecretion of fluid and swelling of the joint.

Osteoarthritis is characterized by three anatomical lesions:

• Involvement of the articular cartilage will crack and hollow ulcers (holes in the cartilage) can leave the bone exposed;
• Reaching the bone itself which decalcifies places (osteoporosis) and condenses in others, especially the part near the joint at the level of pressure zones: it is in osteosclerosis subchondral;
• Training on the edges of the joint small bone growths: osteophytes (sometimes called “parrot beaks” because of their shape radiological).

These lesions may be accompanied by synovitis, which is the inflammation of the lining of the joints.

Causes and risk factors ?

In osteoarthritis, the cartilage destruction corresponds to cracking of the surface to the depth of cartilage. This cracking is due to mechanical phenomena, but it is also favored by biochemical changes in the structure of cartilage.

Basically, we can consider that osteoarthritis is the result:

• Abnormal physical constraints on normal cartilage;
• Physical constraints on normal cartilage abnormal;
• From the combination of the two previous situations.

The main risk factors are suspected:

• General: age, weight, menopause, rheumatism other (chondrocalcinosis, hyperostosis of Forestier …);
• Genetic: the concept of family osteoarthritis is well established for arthrosis of the knee, hip and hand;
• Accommodation:

No major trauma or repeated low (hard work, violent sports, meniscus injury …);
o Abnormal joint position (scoliosis, congenital hip, …);
o Other diseases localized bone or joint pain (arthritis effects, sequelae of fractures, Paget’s disease …).

The origin of osteoarthritis involving many factors that are often poorly known. However, the genetic nature of the disorder seems predominant. There are families and arthritic disease is more frequent in women than men. For example, if certain occupations (work force) are more prone to osteoarthritis than others, all members of this profession will not osteoarthritis (partly based on their genetic predisposition).

Screening for congenital joint abnormalities, followed by a correction in childhood, is of paramount importance to prevent the onset of painful arthritis in adulthood.

Obesity (overweight or simple) is undoubtedly a factor favoring the onset of osteoarthritis in the hips and knees. However, conflicting evidence, not yet explained, are:

• The subjects with osteoarthritis of the knees are much more likely than other arthritis of the hands;
• The ankle joint, but also under strain, is almost never altered in obese patients.

Pain is, in principle, known as type “mechanical” because it has the following characteristics:

• It is triggered and aggravated by movement; It ceases or diminishes more or less completely when the joint is at rest;
• It is less important in the morning, then it increases during the day and it is maximal in the evening;
• It interferes traditionally falling asleep, but can also cause nighttime awakenings (50% of OA patients are awakened at night by their pain);
• It reappears whenever the involved joint is subjected to a force: the march for osteoarthritis of the hip, climbing stairs to the knee, lift the arm to the shoulder …

Eventually, the bony osteophytes cause deformities of joints, especially visible on the hands and knees.The patient’s general condition is still good. There was no fever or weight loss.The arthritic lesions are irreversible and result, in addition to deformation, to stiffening joints may develop into a partial impotence.

It involves the examination of painful joints. It found:

• The existence of pain induced by palpation;
• The joint deformities;
• The range of motion still possible;
• The presence of effusion fluid (knee)
• The questionnaires self-evaluation

Two types of questionnaire types are sometimes used to assess the importance of pain and disability:

• The EVA: Using a visual analogue scale (VAS) allows the patient himself to quantify the importance of pain and disability. Renewed every 3 or 6 months, analysis of EVA allows to quantify the improvement achieved by the treatment or, conversely, to see the worsening of symptoms;
• The functional indices: it is specific questionnaires for knee and hip (Lequesne index) and the main (index Dreiss). Regarding the Lequesne index, it can facilitate the surgical decision-making, but also evaluate the effectiveness or failure of the proposed treatment.

Reviews and analyzes ?

Blood tests

Osteoarthritis does not disrupt the biological results. Sedimentation rate, inflammatory proteins (CRP) are normal. Unlike arthritis, there is no inflammation.There is no biological marker for osteoarthritis. Its diagnosis can only be clinically and radiologically.

Radiology

Plain radiography without preparation, is sufficient to diagnose the disease osteoarthritis.
Four radiographic features are:

• The narrowing of the joint by cartilage destruction (decrease of cartilage thickness);
• A condensation bone under the cartilage;
• The presence of bony outgrowths or osteophytes;
• The presence of geodes (holes in the punch) in the bone around the joint.

There is no parallelism between the degree of radiographic signs and symptoms experienced: significant osteoarthritis on radiography may remain asymptomatic. Conversely, a very painful osteoarthritis may show only modest radiological alterations.

The joint aspiration

It is performed only if there is a large pleural effusion, especially in the knee.
The formula of the liquid collected is type “mechanical” (protein <30 g / L, WBC <1 000 / mm3, neutrophils <50%).
Bone scan, Magnetic Resonance Imaging, arthrogram
All these tests are unnecessary for the diagnosis of osteoarthritis.

They are useful for bone or joint disorders difficult to see on the radiograph. For example, a hip or knee pain with radiographic quasi-normal can sometimes justify the use of one or more of these exams.

Evolution of the disease ?

Some arthritis are rapidly evolving, while others grow only very slowly. The scalability of osteoarthritis is judged solely on the rate of reduction of joint space at radiography. No biological analysis can not assess the development of osteoarthritis.

The evolution of the degenerative disease is to the progressive worsening and locking joints. The appearance of the limitation of movement (ankylosis) and deformation is the major component of surveillance.

The arthritic lesions are irreversible and result, in addition to deformation, to stiffening joints may develop into a partial impotence.

Do not confuse with …

The differential diagnosis of osteoarthritis are all other chronic joint diseases: rheumatoid arthritis, psoriatic arthritis, osteonecrosis, bone tuberculosis, etc..

But we must also eliminate a number of conditions outside of the joint tendinitis, reflex sympathetic dystrophy, etc.. In general, the radiological appearance of the joint and biology make the difference.

Treatment

Lifestyle and dietary measures

Putting to rest the painful joint is essential for painful periods.

The equipment (orthotics) can prevent deformities and to support the joint to avoid pain. It is used especially for resting the joint in the rhizarthrosis (osteoarthritis of the thumb)

It should, however, that this rest is too long, because it is then more difficult to re-engage the joint in question.

Apart from very painful periods, moderate exercise is recommended: for osteoarthritis of the hip, we recommend cycling rather than walking because this sport keeps muscles by using less cartilage of the hip is unloaded weight of the body . For osteoarthritis of the lumbar spine, some calisthenics-cons are listed.

The weight loss greatly increases patient comfort. It is shown that weight loss for overweight patients with osteoarthritis delays progression of the disease.

Medications

The drugs most used in the treatment of osteoarthritis are:

• Simple analgesics: paracetamol
• The anti-inflammatory drugs (NSAIDs) aspirin, diclofenac, etc..
• The anti-inflammatory drugs (corticosteroids) used mostly in intra-articular infiltration.

NSAIDs and corticosteroids have been shown to slow the progression of osteoarthritis to ankylosis.

A number of molecules are proposed as chondroprotective (cartilage protectors) antiarthrosiques yet known. They have not shown they were “pushing” the cartilage destruction, but they slow down the disease progression.

By its action on superoxide dismutase (an enzyme that inactivates free radicals), copper has shown efficacy in OA include pain.

Recently, there appeared a new subclass of NSAIDs indicated for the treatment of osteoarthritis: the coxibs. By their mechanism of action than selective, these drugs are better tolerated than traditional NSAIDs, including gastric level.

Physiotherapy

It is often essential because it helps to push far beyond the onset of joint stiffness. It is also essential to relieve arthritic joints, strengthen the surrounding muscles.

Various other therapeutic

The physical therapy are used: physiotherapy, massages, hydromineral, acupuncture, electrotherapy … Effective on pain, they have not demonstrated their effectiveness on disease progression.

The heat in all its forms (hot packs, hot baths …) relieves pain.

Spa treatments are useful: the life and well-regulated tissue that conducts the therapy client puts to rest his joints, while massage and physical therapy toning his muscles. Some spas offer sulphurous waters, warm and slightly radioactive, other water containing sodium chloride, and others sludge. The waters are used in jet shower, in shower massage, underwater showers, baths in very warm pool for rehabilitation. The pool is particularly favorable to labor reeducation because the joint is relieved of body weight.

Surgery

Preventive surgery can restore the correct mechanical conditions in case of abnormality of the joint: congenital hip dislocation, genu varum, scoliosis …

Conservative surgery (osteotomy, muscle sections …) is sometimes useful in the hip and knee.

In advanced cases the most disabling, articular resection, arthrodesis (blocking definitive articulation), a total joint replacement (hip, knee, finger) may be proposed to the patient.