OA refers to the breakdown, or degeneration, of cartilage and fluid that cushions and lubricates the bones in your joints.

The degeneration leads your bones to begin to rub together, resulting in pain and further wear and tear. OA is a chronic progressive condition—which means that it gets worse over time.

OA can occur in any joint, but OA of the knee is the most common type, affecting more than 10 million Americans. (3)

Symptoms of knee OA

Look for these common signs and symptoms:

  • Joint soreness after overuse or inactivity
  • Joint stiffness after resting or in the morning
  • Pain when moving your knee
  • Pain when using stairs or getting up from a chair
  • Pain that prevents you from exercising your leg
  • Grating or catching when moving your knee
  • Joint pain that feels worse in the evening after a day’s activity
  • Deterioration of coordination due to pain and stiffness
  • Weakened thigh muscles

Causes of knee OA

Knee OA usually develops slowly and gets progressively worse over time. It’s commonly observed when people are middle-aged and older. But you can develop it at any age, following a joint injury or another disorder.

There are certain factors that increase your risk of developing knee OA:

  • Age. The older you get, the higher your risk
  • Weight. Increased body weight increases your risk. Every pound you gain puts 4 more pounds of stress on your knees (4)
  • Injury or overuse. Athletes and people with active jobs are at higher risk
  • Genetics. Recent research suggests that knee OA is partially caused by your genes (5)
  • Muscle weakness. Weakness in the muscles surrounding the knee increases your risk
  • Other diseases. Rheumatoid arthritis, hemochromatosis (having too much iron), and acromegaly (excessive growth hormone) increase your risk

Getting diagnosed with knee OA

Think you have knee OA? Don’t wait. It’s very important that you see a doctor, get a proper diagnosis, and start treatment right away.

The sooner you start treatment, the easier knee OA is to control and the less damage it can cause. Talk to your doctor or use the physician locator to find a specialist.

How is knee OA diagnosed?

There are usually 4 steps to making a diagnosis of OA:

  1. Medical history. This is your doctor’s best tool to diagnose OA. Use the tips below to talk about your symptoms, family history, and past medical conditions
  2. Physical exam. Your doctor will look for typical signs of OA, such as swelling, tenderness, and loss of motion
  3. Joint fluid sample. After applying a local anesthetic, your doctor will take a small amount of fluid from your knee joint. A lab test of this fluid can help confirm OA and rule out other conditions
  4. X-rays or MRIs. These images can show damage inside the joint. Your doctor will be looking for the deterioration of cartilage that is typical of OA

Talking to your doctor

The more you tell your doctor about your knee pain and how it affects you, the more effective your OA treatment will be.

When talking to your doctor, follow the tips below. It may help to write your thoughts down and bring them to your appointment.

  • Describe your knee pain in detail. Are there areas that hurt more than others? At certain times of the day?
  • Discuss the effects on your lifestyle. What activities (such as working, exercising, gardening, and/or golfing) cause you pain?
  • Tell your doctor about lifestyle changes you’ve tried and their results.
  • Mention any medications or treatments you have used for pain relief. What were the results? Were there any side effects?
  • Make sure you talk over the treatment plan your doctor recommends. Following the treatment plan is important—ask for it in writing and bring up any concerns you have.

Knee OA treatment options

There is no cure for knee OA; but there are treatments that can help you manage and live with the condition. (6) The goal of treatment is to decrease pain, maintain or improve joint movement, and limit functional loss so you can enjoy an active life. (6) No treatment works for everybody—so make sure you talk over the options with your doctor before starting any treatment.

According to the American College of Rheumatology (ACR), drug therapy for pain management of OA is most effective when combined with non-pharmacologic strategies. (6) In fact, non-pharmacologic measures should be maintained throughout your treatment period. (6)

knee oa

More information on knee OA

There is a wealth of information available about OA. If you want to learn more, the following websites are excellent resources:

SUPARTZ FX is indicated for treatment of pain in osteoarthritis (OA) of the knee in patients who have failed to respond adequately to conservative non-pharmacologic therapy and simple analgesics, e.g., acetaminophen. You should not use SUPARTZ FX if you have infections or skin diseases at the injection site or allergies to poultry products. SUPARTZ FX is not approved for pregnant or nursing women, or children. Risks can include general knee pain, warmth and redness or pain at the injection site. Full prescribing information can be found here or by contacting customer service at