Introduction
Arthritis of the knee can take many forms, in fact there are over one hundred different types of arthritis, although the most common forms affecting the knees are osteoarthritis ('OA') and rheumatoid arthritis. Although much more common in adults (and increasingly common with age) there are some forms of arthritis that can affect younger people and children.
In general terms, arthritis is where a joint in the body becomes inflamed. The knee is one of the commonest joints to be affected by the condition. Unfortunately, there is no cure as such for arthritis, however there are a number or treatments which can alleviate the symptoms.
Causes
The causes of knee arthritis depend on which form of arthritis is present. The main types of the condition that affect the knee are...
Osteoarthritis
This type of arthritis of the knee is caused by the wearing away of the cartilage between the bones. This is a degenerative disease and so affects older people more than younger people. It generally impacts people from the age of fifty. Malalignment of the joint can predispose to Osteoarthritis.
Rheumatoid arthritis
This type of arthritis is a form of auto-immune disease, where the body's own immune system attacks its own tissue, in the knee affecting the bone, the cartilage and the ligaments as well as the synovial membrane, which surrounds the knee joint. It tends to impact more than one joint and is 'symmetrical' that is it tends to affect the joints on one side of the body only.
Post traumatic arthritis
This term refers to arthritis that develops after injury to the knee. The injuries can be to the cartilage (meniscus), the ligaments or the bone or a combination of these, and symptoms of arthritis can take a long time to appear, or progress rapidly after injury.
Symptoms
Symptoms of knee arthritis include...
- Pain or stiffness of the affected knee, particularly noticeable...
- First thing in the morning.
- After long periods of being seated.
- Going up or down stairs.
- When walking.
- When kneeling down.
- Swelling of the knee.
- Instability of the knee i.e. where the knee feels as it might give way.
- Inability to either straighten or bend the knee.
- Locking of the knee.
- Noticeable noises, such as a clicking, creaking or popping noise, or a grinding sound (referred to as 'crepitus').
In most cases, symptoms appear gradually over time and get worse, although sudden onset of symptoms can happen. The weather can also impact symptoms, getting worse often during damp weather. In almost all cases of knee arthritis, being overweight makes symptoms worse and simply reducing weight will generally improve them.
Tests / Diagnosis
A physical examination and review of medical history will allow an initial diagnosis. Further tests may be needed to confirm a diagnosis. These may include...
X-rays
X-rays will show any changes to bone structure, such as bone spurs (called 'osteophytes') and will indicate which type of arthritis is present
MRI / CT scans
These may be necessary to visualise bone density and to analyse soft tissues in the knee joint
Blood tests
These also help to determine the type of arthritis present.
Non-operative Treatment
Knee arthritis can often be managed with a combination of non-surgical treatments. Your General Practitioner will be able to help with the implementation of these. Some options include.
- Gait aids such as walking sticks or frames.
- Other aids to help with tasks such as getting out of chairs or picking up objects from the ground.
- Physio or hydrotherapy, exercise programs designed to keep you mobile.
- Paracetamol or Non-Steroidal anti-inflammatory medications.
- Supplements such as fish oil, turmeric extract, or a specific anti-inflammatory diet.
- Losing weight if you are overweight.
Excellent information is available at Arthritis Australia.
Related Information
Anatomy of the Knee
Total Knee Replacement (TKR)
Arthritis of the Knee