Osteoarthritis of the knee: an overview and more

The knees are the joints most commonly affected by osteoarthritis (OA). Knee arthritis occurs when the cartilage in the knee breaks, which can occur due to aging, being overweight, or injury, among other things. The disease begins before symptoms are noticed: pain, stiffness, and limited movement. Because of this, and because knee osteoarthritis is a progressive disease, getting a diagnosis and receiving the appropriate treatment as soon as possible is key.

More than 14 million Americans have knee osteoarthritis. It is the most common cause of musculoskeletal disability in the United States. About 13% of women and 10% of men age 60 and older have symptomatic osteoarthritis of the knee joint.

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Knee osteoarthritis develops gradually over a period of time and usually goes unnoticed until it becomes symptomatic, often causing:

As knee osteoarthritis progresses, symptoms often become more severe. The pain can become permanent and does not only occur when you are standing, walking, or doing physical activity.

In the later stages of OA, the crepitus (a grinding sensation) can become noticeable. There may also be a visible deformity of the joint or a feeling that the knee is about to " give out."

Usually one knee is more affected than the other, but both can be affected, often at different times. The most commonly affected patellofemoral joint (front of the knee) and the medial tibiofemoral joint (inside of the knee). The lateral tibiofemoral joint (outside the knee) is less common.


Osteoarthritis of the knee is caused by the destruction of cartilage , the protective tissue that allows the bones that make up the joint to slide smoothly over each other. After all, the cartilage loss can be so severe that virtually no debris is left to cover the ends of the bones in the knee joint (this is called a bone- on-bone abnormality). Loose bodies in the joint space can also contribute to pain and stiffness.

Cartilage loss in knee joint osteoarthritis can be caused by:

  • Aging
  • Previous knee injury, such as a fracture, torn ligament, or meniscus injury, which can affect knee and leg alignment, further contributing to wear and tear.
  • Constant strain on the knee.
  • Genetic predisposition to cartilage abnormalities and knee osteoarthritis.
  • Obesity and overweight, which increase stress on the affected joint and increase pro-inflammatory cytokines .
  • Subchondral bone problems (the layer of bone under the knee cartilage)


As with any type of suspected arthritis, the first consultation with your healthcare provider begins with a discussion of your symptoms. The location of the pain and the time of its appearance will help in the diagnosis of osteoarthritis of the knee joint:

  • Pain in the front of the knee (patellofemoral joint) is often worse when sitting for a long time, getting up from a low chair, going up stairs, or going down a hill.
  • There is usually no pain below the knee, unless it is associated with a Baker's cyst .
  • Knee pain can interrupt your sleep (in advanced cases).

This is followed by a review of your medical history and a physical exam. Your treating physician:

  • Examine the affected knee for swelling, warmth, and deformity, which may indicate osteoarthritis or other conditions.
  • Passively and actively assess range of motion.
  • See if there is tenderness to the touch.
  • Watch your gait for changes in gait and signs of increased pain when weight is applied.

You should also wait for blood tests to rule out other types of arthritis and imaging tests to look for evidence of structural changes consistent with osteoarthritis and for differential diagnosis.

X-rays are ordered first, and if a more detailed image is required, you can order an MRI or computed tomography (CT) scan. The condition of the knee can also be observed during arthroscopic knee surgery .

The exam and pictures will show which component of the knee is affected.

Watch out

OA of the knee cannot be cured, but there are treatments that can help control symptoms. In 2019, the American College of Rheumatology and the Arthritis Foundation updated their guidelines for the treatment and management of knee osteoarthritis. 'Strongly recommended' treatments have more evidence of benefit than 'conditionally recommended' treatments.

Knee replacement surgery is used as a last resort after conservative treatment has failed.

Note that there are several treatments that ACR / AF strongly advises against for knee osteoarthritis: glucosamine, chondroitin, bisphosphonates, hydroxychloroquine, biologics, stem cell injections, hyaluronic acid injections, platelet rich plasma, and transcutaneous electrical stimulation (TENS). ) …

The guidelines also temporarily discourage other treatments. Ultimately, you and your healthcare provider will consider the pros and cons of each option to determine which one might be safe and effective for you.

Get the word of drug information

To control knee osteoarthritis, it is necessary to recognize the early symptoms and consult a doctor for an accurate diagnosis. Once diagnosed, adhere to a regimen of proven and effective treatment options. Protect your joints by paying special attention to modifiable factors that can affect disease progression.

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