Arthritis of the knee: Causes, symptoms, and treatment
What is arthritis?
Arthritis is inflammation which can affect one or more joints, causing pain and stiffness. Rather than being one single disease, there are actually over 100 different forms of arthritis, and it is a leading cause of chronic pain and disability among Australians especially as the population ages.
Read on to find out more about the causes and pain associated with arthritis of the knee, as well as the treatment options available to aid in recovery.
What causes arthritis of the knee?
The knee is the largest and strongest joint in the body, and is made up of three bones: the lower end of the femur (thighbone), the upper end of the tibia (shinbone), and the patella (kneecap).
Where the three bones touch, they are covered with articular cartilage, which cushions the bones as the knee bends and straightens. The meniscus are two additional wedge-shaped, rubbery pieces of cartilage which provide shock absorption between the thighbone and shinbone.
The knee joint is also surrounded by the synovial membrane which is responsible for lubricating the cartilage and reducing friction.
While there are over 100 types of arthritis, the most common ones affecting the knee are:
The most common form of arthritis, Osteoarthritis is caused by wear and tear, and most commonly affects people over the age of 50.
Osteoarthritis wears away the articular cartilage (the smooth outer covering of the bone), causing the protective space between the bones to decrease. This results in the bones of the affected joint rubbing together during movement, causing pain and bone spurs to develop.
Osteoarthritis develops slowly and worsens over time.
Rheumatoid arthritis is a chronic autoimmune disease that attacks multiple joints throughout the body by causing the synovial membrane to swell, resulting in pain and stiffness.
Rheumatoid arthritis usually affects the same joint on both sides of the body.
A form of osteoarthritis, posttraumatic arthritis occurs as a result of an injury such as a fracture or dislocation.
Instability from meniscal tears and ligament injuries can cause additional wear on the knee joint, which can result in arthritis.
What are the symptoms of arthritis of the knee?
Pain and inflammation are common symptoms of arthritis of the knee, with the pain usually developing slowly over time. The pain is often worse in the morning or after periods of inactivity, and some people notice more pain with changes in the weather (particularly cold weather).
Other symptoms include stiff and swollen knee joints, difficulty bending and straightening the knee, pain during or after vigorous exercise, weakness or buckling in the knee, and the feeling of the knee “locking” and making creaking, clicking, or grinding noises (called crepitus) during movement.
How is arthritis of the knee diagnosed?
Arthritis of the knee can be diagnosed through physical examination (your doctor will look for signs of weakness, previous and current injuries, problems weight-baring and walking, and pain and tenderness among other symptoms), x-rays, and sometimes an MRI or CT scan.
Blood tests can also be useful for detecting certain types of arthritis, such as rheumatoid.
What treatment options are available for arthritis of the knee?
While there is no cure for arthritis, there are treatment options available which may help to relieve pain and keep active.
Initially, arthritis of the knee may be treated with non-surgical options such as rest, icing / heat, physiotherapy, anti-inflammatory medications, changes to activity, and steroid injections.
Switching high-impact activities such as running to lower-impact activities like swimming, as well as losing weight can help to reduce stress to the affected joints. Devices such as a cane, knee brace, bandaging, and shock-absorbing insoles may also help.
If these treatment options are unsuccessful, surgery may be necessary.