To mark Rheumatoid Arthritis awareness week, we are looking at this painful condition and how it can affect the knee joint, as well as other parts of the body.
What is Rheumatoid Arthritis?
Rheumatoid arthritis (RA) is a chronic inflammatory disorder. Unlike osteoarthritis, this form of arthritis affects more than just your joints. It is an autoimmune condition that causes your immune system to mistakenly attack your body’s own tissues. For some people this can result in damage to the heart, lungs, eyes, skin and blood vessels, alongside joint damage.
Rheumatoid arthritis damages the lining of your joints, causing painful swelling. Inflammation resulting from the condition spreads to other parts of the body and can cause joint deformity and bone erosion. The condition often affects smaller joints first, such as fingers and toes, before spreading to larger joints.
Rheumatoid Arthritis of the knee
Whereas osteoarthritis of the knee is due to wear and tear and so may affect only one knee joint, rheumatoid arthritis normally affects both.
The condition causes the synovial membrane surrounding the knee joint to swell, resulting in knee pain and stiffness. The immune system attacks the cartilage and ligaments, and softens the bone.
Symptoms of knee Rheumatoid Arthritis
Symptoms of rheumatoid arthritis in the knee include:
- Tender, swollen knee joints that feel hot to the touch
- Joint stiffness that is worse when you wake or after inactivity
- Loss of appetite
Around 40% of people with the condition will also experience symptoms in other parts of the body, including the major organs (heart, lungs, kidneys), eyes, skin, nerves, blood vessels and bone marrow. You are also at greater risk of developing other problems such as osteoporosis, lymphoma, carpal tunnel syndrome, infections and rheumatoid nodules.
Symptoms may vary in severity and you may experience some periods of remission. Over time, however, joints are likely to become degenerate and deformed.
Causes of RA in the knee
Rheumatoid arthritis of the knee occurs when your immune system attacks the synovium which is the membrane that surrounds your joints. Inflammation causes the synovium to thicken and may eventually destroy cartilage and bone in your knee. Tendons and ligaments weaken and stretch, causing the knee joint to become unstable and slip out of alignment.
Doctors are unsure precisely what triggers rheumatoid arthritis but genetics are believed to make people more susceptible and certain environmental factors, such as bacteria and viruses, may trigger the disease. Factors that increase your likelihood of developing rheumatoid arthritis include:
- Family history – if someone in your family has the condition you are at increased risk.
- Smoking increases your risk particularly if you are already genetically predisposed to the disease. It also increases the severity of the disease.
- Obesity, particularly in women.
- Exposure to certain materials such as asbestos and silica.
- Being female.
- Age – the condition develops most commonly in middle age, although it can occur at any age.
Treatment of RA
Whilst there is no cure for rheumatoid arthritis, there is a range of treatments that can help you to manage the symptoms. These include:
- Medication – anti-inflammatories can reduce inflammation and so can steroids, which may also slow joint damage. Disease-modifying antirheumatic drugs (DMARDs) can slow the progress of the disease and may prevent damage to other joints and tissues. However, there are potentially serious side-effects so they will not be prescribed in every case. Biologic agents are the latest generation DMARDs, developed to target the parts of the immune system that trigger inflammation which causes tissue damage. Often, they are prescribed in conjunction with a nonbiologic DMARD.
- Therapy – a physiotherapist or occupational therapist can recommend exercises to maintain joint flexibility and may be able to advise on ways of performing day-to-day tasks that prevent excessive strain on your joints. They may also be able to signpost you to assistive devices to help with everyday living.
- Surgery – if medications fail to prevent joint damage, there is a range of surgical options to repair or replace damaged joints. These can include arthroscopic (keyhole) knee surgery through to actual joint replacement surgeries when the damage is severe.
For more advice about living with rheumatoid arthritis, contact us.