Overview of Knee Osteoarthritis

Pain in a knee
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Knee osteoarthritis is the most common type of osteoarthritis. More than 10 million Americans have knee osteoarthritis. It is also the most common cause of disability in the United States. Early diagnosis and treatment help manage knee osteoarthritis symptoms. An overview of knee osteoarthritis will help you understand symptoms, diagnosis, and treatment options.


Deterioration of articular cartilage is the main problem associated with knee osteoarthritis. The question then is what is causing this deterioration? The condition can be caused by:

  • Previous knee injury
  • Repetitive strain on the knee
  • Fractures, ligament tear, and meniscal injury which can affect the alignment of the knee and leg and promote further wear and tear
  • Genetics, which makes some people more likely to develop knee osteoarthritis
  • Obesity; being overweight or obese raises your risk of knee osteoarthritis
  • Problems with subchondral bone (the bone layer underneath the cartilage in the knee)


To make the diagnosis of knee osteoarthritis and to rule out other conditions, your physician will take your medical history, do a physical examination, and order X-rays of the knee. These X-rays are an important diagnostic procedure for osteoarthritis, allowing the doctor to see evidence of joint space narrowing and to rule out other causes of knee pain. If more detailed imaging is needed, an MRI may be ordered and performed to get a better look. Arthroscopic knee surgery is another way to view the condition of the knee.


Knee osteoarthritis typically develops gradually over a period of years. The primary symptoms associated with knee osteoarthritis include:

  • Pain in the knee, which can be mild, moderate, or severe
  • Stiffness of the knee joint
  • Limited range of motion in the knee, you can't bend it as far as is normal
  • Localized swelling of the knee

Knee osteoarthritis pain is usually worse following activity, especially overuse of the affected knee. Stiffness can worsen after sitting for prolonged periods of time. As knee osteoarthritis progresses, symptoms generally become more severe. Pain can become continuous rather than only when weight-bearing.


Knee osteoarthritis cannot be cured but there are treatments available to help manage the symptoms. Medications, starting with acetaminophen, can help manage and relieve pain. Some patients obtain better pain relief when using NSAIDs (nonsteroidal anti-inflammatory drugs) or Celebrex, the one remaining COX-2 selective inhibitor. There are opioid analgesic medications available for patients who need stronger pain relief.

Aside from medications, other treatments include:

Getting diagnosed and treated while knee osteoarthritis is still in the early stages is most beneficial. If treated early, many people can effectively manage mild to moderate knee osteoarthritis.

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Article Sources

  • A Patient's Guide to Osteoarthritis of the Knee. Center for Orthopaedics and Hip and Knee Surgery. 7/29/2007.
  • Osteoarthritis of the Knee. JAMA. February 26, 2003 - Vol. 289. No.8.