In recent years, stem cell therapy has been hailed as a miracle cure for many conditions, from wrinkles to spinal repair. In animal studies, stem cell treatments have shown promise for various diseases, including heart disease, Parkinson’s disease and muscular dystrophy.

Stem cell therapy could also potentially treat osteoarthritis (OA) of the knee. In OA, the cartilage covering the ends of the bones starts to deteriorate and wear away. As the bones lose this protective covering, they start to rub against one another. This leads to pain, swelling, and stiffness — and, ultimately, loss of function and mobility.

Millions of people in the United States live with OA of the knee. Many manage their symptoms through exercise, weight loss, medical treatments, and lifestyle modification.

If symptoms become severe, total knee replacement is an option. Over 600,000 people a year undergo this operation in the United States alone. Yet stem cell therapy can be an alternative to surgery.

The human body is constantly manufacturing stem cells in the bone marrow. Based on certain conditions and signals in the body, stem cells are directed to where they are needed.

A stem cell is an immature, basic cell that has not yet developed to become, say, a skin cell or a muscle cell or a nerve cell. There are different types of stem cells that the body can use for different purposes.

There is evidence that stem cell treatments work by triggering damaged tissues in the body to repair themselves. This is often referred to as “regenerative” therapy.

However, research into stem cell treatment for OA of the knee is somewhat limited, and the results of studies are mixed.

The American College of Rheumatology and the Arthritis Foundation (ACR/AF) do not currently recommend stem cell treatment for OA of the knee, for the following reasons:

  • There is not yet a standard procedure for preparing the injection.
  • There is not enough evidence to prove that it works or is safe.

Currently, the Food & Drug Administration (FDA) considers stem cell treatment “investigational”. Until additional studies can demonstrate a clear benefit from stem cell injections, people who opt for this treatment must pay for them on their own and must understand that the treatment may not work.

That said, as researchers learn more about this type of treatment, it could one day become a viable option for the treatment of OA.

The cartilage covering the ends of the bones enables the bones to glide smoothly against one another with only slight friction. OA causes damage to the cartilage and leads to increased friction — resulting in pain, inflammation, and ultimately, a loss of mobility and function.

In theory, stem cell therapy uses the body’s own healing mechanisms to help repair and slow the deterioration of body tissues, such as cartilage.

Stem cell therapy for knees aims to:

  • slow and repair damaged cartilage
  • decrease inflammation and reduce pain
  • possibly delay or prevent the need for knee replacement surgery

In simple terms, treatment involves:

  • taking a small amount of blood, usually from the arm
  • concentrating the stem cells together
  • injecting the stem cells back into the knee

Several studies have concluded that stem cell therapy improves arthritis symptoms of the knee. While overall results are promising, more research is needed to discover:

  • how it works
  • correct dosage
  • how long the results will last
  • how often you’ll need the treatment

Stem cell treatment for knees is noninvasive, and studies suggest that side effects are minimal.

After the procedure, some people may experience temporary increased pain and swelling. However, the overwhelming majority of people who get stem cell injections have no adverse side effects.

The procedure uses stem cells that come from your own body. In theory, this dramatically reduces the risk of any serious side effects. However, there are various ways of harvesting and processing the stem cells, which likely affects the various success rates of the published studies.

Before receiving any treatment, it’s best to:

  • learn as much as you can about the procedure and how it works
  • ask your doctor for advice

Despite conflicting evidence about whether stem cell injections work, many clinics offer them as an option for the treatment of arthritic knee pain.

Since stem cell treatment for arthritic knee pain is still considered “investigational” by the FDA, the treatment is not yet standardized and there is no limit to what doctors and clinics can charge.

The cost can be several thousands of dollars per knee and most insurance companies do not cover the treatment.

If OA is causing knee pain or affecting your mobility, the ACR/AF recommend the following options:

  • exercise and stretching
  • weight management
  • over-the-counter anti-inflammatory medication
  • steroid injections into the joint
  • heat and cold pads
  • alternative therapies, such as acupuncture and yoga

If these don’t work or become ineffective, a total knee replacement surgery may be an option. Knee replacement surgery is a very common operation that can greatly improve mobility, decrease pain, and significantly improve quality of life.

Research into stem cell therapy for treatment of osteoarthritic knee pain is ongoing. Some research has shown promising results and it may one day become an accepted treatment option. For now, it remains costly and experts remain cautiously optimistic.