Knee Osteoarthritis: Overview
Osteoarthritis is the most common form of arthritis, and approximately 10 million people in America have osteoarthritis in the knees.
During your life, your knees go through a lot—these joints cushion your movements and help support your weight. Over time, this natural wear and tear process can lead to osteoarthritis (OA) in the knees. This is when the cartilage, which normally cushions your joints, wears away. The joints aren’t as protected as they should be then, and the bones in your knees can starts to rub on each other, leading to pain, stiffness, and swelling.
At the ends of bones, you have cartilage, which is a slippery tissue that helps bones glide over each other—it keeps the joints working smoothly. Additionally, cartilage works as a shock absorber for your movements.
If you develop osteoarthritis, the top layer of your cartilage around the joints starts to break down and erode. As it wears away, the bones can rub together, and bone-on-bone rubbing can cause pain, swelling, and less movement in your joint.
As more time passes, the joint affected by osteoarthritis may lose its normal shape. You also may develop bone spurs on the edges of the joint. You may have bits of bone and/or cartilage break off your joint; they then “float” in the joint space, and that can cause more damage and pain.
Knee Osteoarthritis Causes
Currently, researchers don’t understand the exact cause of knee osteoarthritis. Many factors can lead to the degeneration of the knee cartilage, including overuse and injury. But sometimes, knees can develop osteoarthritis without a clear cause.
Some factors that influence the development of osteoarthritis are:
- Age:The older you are, the more likely it is that you will develop osteoarthritis. We put our joints through a lot of daily stress, and over the years, this can start to wear down the cartilage. Most people affected by osteoarthritis are older than 45.
- Playing particular sports:Running, soccer, and tennis all put extra strain on the knee joint, and this can lead to the eventual development of osteoarthritis.
- Repetitive stress:This is similar to playing certain sports—it’s all about the strain you put on your knees. Certain jobs that require a lot of lifting, squatting, or kneeling may make people more prone to osteoarthritis.
- Weight:If you carry extra weight, this can put more strain on the knee joint, making it more likely to wear out.
- Gender:In people older than 45, women are more likely than men to develop osteoarthritis.
- Heredity:It is known that genetics plays a role in developing osteoarthritis. If someone in your family has or had osteoarthritis, you may be more at risk for developing it.