Understanding Osteoarthritis of the Knee

Front view of knee showing osteoarthritis.A joint is a place where two bones meet. The knee is called a hinge joint. This joint is formed where the thighbone (femur) meets the shinbone (tibia). A healthy knee joint bends freely. Knee osteoarthritis is a condition where parts of the knee joint wear out. This can lead to pain, stiffness, and limited movement. 

What is osteoarthritis?

Every joint contains a smooth tissue called cartilage. Cartilage cushions the ends of bones and helps bones in a joint glide smoothly against each other. Knee osteoarthritis occurs when cartilage in the knee joint begins to break down and wear away. Bones may become exposed and rub together. The cartilage may become irritated and rough. This prevents smooth movement of the joint and can lead to pain.

Causes of osteoarthritis of the knee

Causes can include:

  • Wear and tear from normal use over time

  • Overuse of the knee during sports or work activities

  • Being overweight. This increases stress on the knee joint.

  • Misalignment of the knee joint

  • Injury to the knee

Symptoms of osteoarthritis of the knee

Common symptoms include:

  • Pain and swelling around the joint. The pain and swelling get worse with activity and better with rest.

  • Grinding sound when moving the knee

  • Reduced knee movement

  • Knee stiffness. This is often worse first thing in the morning.

Treating osteoarthritis of the knee

Osteoarthritis is a long-term condition. Treatment usually focuses on managing symptoms. Treatment may include:

  • Over-the-counter or prescription medicines taken by mouth to help relieve pain and swelling

  • Injections of medicine into the joint to help relieve symptoms for a time

  • A weight-loss plan for people who are overweight

  • A plan of physical therapy and exercises to improve the strength and flexibility of the muscles around the knee

  • Heat or cold therapy to help relieve pain and stiffness

  • Assistive devices that help with movement, such as a cane or a walker

  • Assistive devices that make activities of daily life easier, such as raised toilet seats or shower bars

If other treatments don’t do enough to relieve symptoms, you may need surgery to replace the joint. During this surgery, the damaged joint is removed. An artificial knee joint is then put into place. This can help relieve pain and stiffness and restore movement of the knee.


When to call your healthcare provider

Call your healthcare provider right away if you have any of these:

  • Fever of 100.4°F (38°C) or higher, or as directed

  • Symptoms that don’t get better with prescribed medicines or get worse

  • New symptoms