Osteoarthritis

What osteoarthritis is

The ends of the bones inside a joint are covered with cartilage, a smooth, elastic tissue that lets the bones glide over one another and absorbs shocks. In osteoarthritis this cartilage thins, becomes rough and cracks. But the disease is not just “wear and tear”: it affects the whole joint. The bone beneath the cartilage thickens and forms osteophytes (small bony outgrowths), the joint lining becomes partly inflamed and the surrounding muscles weaken. When the disease affects the knee it is called gonarthrosis, when it affects the hip, coxarthrosis, and when it affects the hands, especially the end joints of the fingers, it forms visible thickened knuckles.

It is very common with age, but it is not an inevitable result of aging: many older people have pain-free joints. Unlike rheumatoid arthritis, osteoarthritis is not an autoimmune disease.

Symptoms

• pain that increases with use of the joint: when walking, on stairs, after standing for a long time, and eases with rest;
• stiffness after rest or in the morning, which passes within a few minutes (usually under 30 minutes);
• creaking or a “gravel” feeling in the joint with movement;
• occasional swelling, especially of the knee, from fluid in the joint;
• reduced mobility and, in advanced stages, pain even at rest or at night;
• in the hands: thickened, tender joints at the fingertips.

The course is often variable: there are better periods and others with flares, for example after an unusual load. The severity of pain does not always match the picture on an X-ray.

Risk factors

• age (it appears more often after 45–50);
• overweight, which loads the knee and hip, but also joints that do not bear weight (the hands), because fat produces inflammatory substances;
• earlier joint injuries (torn ligaments, menisci, fractures);
• work or sport with repeated load on the same joints;
• female sex and heredity;
• congenital deformities of the joint or leg axis, and other diseases such as diabetes or gout.

Diagnosis

The diagnosis is mainly clinical: the doctor suspects osteoarthritis when a person over 45 has pain that increases with use of the joint and brief morning stiffness. During the examination, movement, swelling, creaking and muscle strength are assessed. In most cases no tests are needed; they are done only to rule out other diseases (rheumatoid arthritis, gout).

X-ray shows narrowing of the joint space and osteophytes (done at an imaging center) and is not necessary in every case. Joint ultrasound shows fluid and inflammation in the joint, the state of the tendons and helps choose treatment, including injections under ultrasound guidance. Magnetic resonance imaging is recommended only when other injuries (meniscus, ligament) are suspected.

Treatment

There is no medicine that restores cartilage, but there are many effective ways to control pain and preserve function. The foundation of treatment is not drugs:

Exercise and weight. Exercises to strengthen muscles, especially the quadriceps for the knee and the hip muscles, together with regular movement (walking, cycling, swimming), are the most effective treatment, even when the joint hurts. Strong muscles share the load on the joint. Every kilogram lost markedly reduces the load on the knee while walking, so weight loss in people who are overweight is the intervention with the greatest benefit. Suitable shoes and a cane or walking aid when needed also help.

Medicines. They are used as needed and for a limited time: anti-inflammatory creams or gels on the skin, and oral anti-inflammatory drugs (NSAIDs) at the lowest effective dose and for the shortest time possible, because they can harm the stomach and kidneys and raise blood pressure or cardiovascular risk, so they must be used carefully in older people and in people with heart disease, kidney disease, ulcers or who take anticoagulants; paracetamol has a limited effect. Do not use them on your own for months without your doctor’s advice.

Intra-articular injections. A corticosteroid injected into the joint (especially when there is swelling or fluid) reduces pain for weeks to months, but is not repeated often. Hyaluronic acid is used in some knee cases; the evidence for its effect is mixed and not all guidelines recommend it, so the decision is made with the doctor case by case. The doctor can perform injections under ultrasound guidance.

Surgery. In advanced cases, when pain is severe, limits daily life and other treatment no longer helps, joint replacement (of the knee or hip) is discussed, an operation with very good results for the right patients. Supplements such as glucosamine and chondroitin have weak evidence of benefit.

Follow-up

Osteoarthritis is a chronic disease and is followed according to its course. When pain is controlled, one check every 6 months to a year is enough, or sooner when the doctor considers it reasonable: when it worsens, when you are to have an injection or when side effects of medicines appear. In practice, what changes the outcome most is consistency with exercise and weight control, not the medicines themselves.

This information is educational and does not replace a medical visit.

When to see a doctor

• pain that limits your walking or sleep;
• a swollen, warm joint, especially with fever;
• when painkillers are no longer enough or you need them every day;
• new sudden pain after a fall;
• when you want to start an exercise program and want to know what is safe for your joints.