About Osteoarthritis

What is Osteoarthritis?

Osteoarthritis (OA) is the most common type of arthritis, also known as degenerative joint disease, for which there is no cure. It is a common, chronic, progressive musculoskeletal disorder.

In an osteoarthritic joint, the surface layer of cartilage gradually breaks down and wears away. The bones in the joint that are now exposed rub together, causing pain, swelling, and loss of motion. Over time, the joint may lose its normal shape. In addition, small deposits of bone, called bone spurs, may grow on the edges of the joint. These can break off and float inside the joint space, causing even more pain and damage.

More than 80% of individuals over 50 years old have some radiographic evidence of osteoarthritis.1 Patients suffering from OA often face chronic pain that worsens over time. Most commonly affecting middle-aged and older people, OA can range from very mild to very severe. There are certain factors that can increase a person’s risk for developing osteoarthritis.


  • Aging: as a person gets older, the body’s ability to heal damaged or lost cartilage decreases
  • Joint injury: younger people can also develop OA due to joint injury, for example, athletes who have suffered from a sports-related knee injury
  • Heredity: if there is a family history of OA, the risk for developing the disease increases
  • Repeated joint stress: excess weight or overuse of the joint causes stress or increased wear and tear on the joint
  • Muscle weakness: if the muscles that surround the joint are weak, added stress is placed on the joint
  • Joint disorder: if there is a joint malformation or a genetic defect in the joint cartilage


Osteoarthritis is the most prevalent joint disorder worldwide and is associated with significant pain and disability.2 It is a progressive disease that can affect any joint but most often involves the weight bearing joints.

Joints that can be affected include:

  • Knees
  • Hips
  • Ankles
  • Spine – neck and lower back
  • Hands – fingers and thumbs
  • Shoulders

Knee OsteoarthritisGreater than 5% of the world’s population is afflicted by OA of the knee. Because of the high prevalence of knee OA, this disease ranks as either the top or second leading cause of disability.3


  • Pain
  • Swelling
  • Stiffness
  • Loss of physical function
  • Loss of motion in the joint
  • A crackling sound when moving the joint


Hyaluronic acid (HA) is a naturally occurring biocompatible molecule found throughout the body that is a vital component of healthy joint and tissue function. HA is naturally found in high concentrations in the synovial fluid that bathes the knee joint and other joints. Synovial fluid dramatically reduces friction and helps lubricate and cushion the knee, allowing the bones to glide smoothly against each other and absorbing the shock from physical movement.

Osteoarthritis causes the natural hyaluronic acid to break down leaving lower concentrations of HA in the synovial fluid surrounding the knee joint. As a result, the synovial fluid becomes thinner and less effective at cushioning, lubricating and protecting the knee.

It is vital to replace some of the lost hyaluronic acid (HA) in order to help restore healthy joint function.


Living with osteoarthritis can not only be painful, but can be discouraging. Osteoarthritis is the most common cause of knee pain. Patients who think they may have OA should talk to their doctor. Although there is no cure for the disease, the sooner patients start treatment, the more manageable their OA may become, and the longer they may be able to delay surgery or total knee replacement.


1. Loeser, R., MD. Age-Related Changes in the Musculoskeletal System and the Development of Osteoarthritis. Clin Geriatr Med. 2010 Aug; 26(3): 371–386. doi: 10.1016/j.cger.2010.03.002.

2. Markenson, J., MD. An In-Depth Overview of Osteoarthritis. Hospital for Special Surgery. Web: https://www.hss.edu/conditions_an-in-depth-overview-of-osteoarthritis.asp

3. Guccione, A.A., et al., The effects of specific medical conditions on the functional limitations of elders in the Framingham Study. American journal of public health, 1994. 84(3): p. 351-8.

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