What is osteoarthritis of the knee?
Osteoarthritis of the knee happens when the cartilage in your knee joint breaks down, enabling the bones to rub together. The friction makes your knees hurt, become stiff and sometimes swell. While osteoarthritis in the knee can’t be cured, there are many treatments to slow its progress and ease your symptoms. Surgery is an option for more severe forms of osteoarthritis.
How common is osteoarthritis of the knee?
Osteoarthritis of the knee is very common. Approximately 46% of people will develop it during their lifetimes.
Who is affected by osteoarthritis of the knee?
Women are more likely than men to develop osteoarthritis of the knee. Most people develop this condition after age 40. But other factors such as injury or genetics can cause it to happen earlier.
How does osteoarthritis in the knee affect my body?
Knee pain is the most common symptom of osteoarthritis in the knee, making it painful for you to jog, run, climb stairs or kneel. It can also make your knees feel stiff or swollen. Over time, osteoarthritis of the knee can change the shape of your knee joint, making your joint feel unstable or wobbly.
Symptoms and Causes
What causes osteoarthritis of the knee?
Osteoarthritis of the knee happens when your knee joint cartilage wears out or is damaged. Articular cartilage is tough, rubbery tissue on the ends of your bones that lets you bend and move. Meniscal cartilage absorbs shock from pressure on your knee.
Your cartilage is like your car’s shock absorber, protecting your car from bumps and jolts. Drive on lots of rough roads, your shocks wear out fast. Drive on easy streets, your shocks last longer. You can wear out or damage your knee joint cartilage if:
You’re overweight. If your body mass index (BMI) is 30 or more, you’re seven times more likely to develop osteoarthritis in your knee than someone with a lower BMI.
You injure your knee or have an old knee injury.
You frequently put stress on your knee at your job or playing sports.
You inherited a tendency to develop osteoarthritis of the knee.
You have crooked bones or joints, such as having knocked knees.
What are the symptoms of osteoarthritis in the knee?
Pain is the most common symptom of osteoarthritis in the knee. Your knee might hurt when you move it, or even when you are just sitting still. Other symptoms are:
Your knee feels stiff, particularly when you first get up or when you’ve been sitting for a long time.
Your knee looks swollen or feels puffy.
You hear a cracking or grinding noise when you move your knee.
Your knee feels wobbly, as if it could buckle or “give out.”
Your knee might lock up, or feel as if it is stuck.
Diagnosis and Tests
How is osteoarthritis of the knee diagnosed?
Your healthcare provider will do a physical examination and ask about your medical history. The physical examination might include checks to see:
If your knee joint area is red or sore.
If there’s a sign you injured your knee.
How much you can move your knee. This is called your range of motion.
If your knee feels “loose,” which can mean your joint isn’t stable.
The way you walk, in case you have gait problems that affect your knee. A gait problem is when you don’t walk as you would normally.
