Osteoarthritis of the knee
The knee is the part of the body most commonly affected by osteoarthritis.
Osteoarthritis of the knee can cause pain, discomfort and loss of joint movement due to the wear and tear over the years.
With osteoarthritis, the cartilage in the knee gets thinner so that it can no longer effectively stop the bones rubbing together, or act as a shock absorber.
Who gets osteoarthritis of the knee?
The National Institute for Health and Care Excellence (NICE) says around 8.5 million people in the UK are affected by joint pain from osteoarthritis. In over 45 year olds, knees are the joints most often affected by osteoarthritis and women aged 75 and over are the group with the highest prevalence of knee pain.
What causes osteoarthritis of the knee?
Osteoarthritis of the knee may happen as a result of injury or infection but often there is no obvious precipitating cause. Some of the following risk factors may play a part in the developing of osteoarthritis of the knee:
- Inherited genes. This includes the possibility of genetic mutations that might make a person more likely to develop osteoarthritis of the knee.
- Age. The ability of cartilage to heal decreases as a person gets older.
- Gender. Women who are 50 years old and over are more likely than men to develop osteoarthritis of the knee.
- Repetitive stress injuries. These are usually a result of the type of job a person has. Certain occupations that include a lot of walking (over 3.2km/2 miles per day), kneeling, squatting or lifting heavy weights (25kg/55lb or more) have higher incidences of osteoarthritis of the knee because of the constant pressure on the joint.
- Weight. Body weight increases pressure on all the joints including the knees.
- Athletics. Athletes involved in football, tennis or long-distance running are at higher risk of developing osteoarthritis of the knee.
- Other illnesses. This includes gout and certain metabolic disorders.
What are the symptoms of osteoarthritis of the knee?
Symptoms of osteoarthritis of the knee may include:
- Pain that increases when you are active, but gets a little better with rest
- Feeling of warmth in the joint
- Stiffness in the knee, especially when you have been sitting for a while
- Decrease in mobility of the knee, making it difficult to get in and out of chairs or cars, use the stairs or walk
- Crepitus, or a creaking, crackly sound that is heard when the knee moves
- Physical changes in the bone as found by X-rays or bone scans