Marc Darrow MD,JD

A Baker’s cyst can be a very confusing knee ailment for some patients. First, it has nothing to do with being a baker, but rather it was named for the surgeon who first described it, Dr. William Baker. Secondly, often it is not explained by the attending physician that the Baker’s cyst itself is not the cause of the patient’s knee problems, but rather a symptom of knee instability and developing osteoarthritis.

Typically a patient will call or email our office asking for help for the problems of Baker’s Cyst. Some of these patients have had the cyst drained before and it has returned. Most tell us that the orthopedist who drained the cyst the first or even second time warned them that the cyst will return and that they will need some type of knee surgery to prevent it from coming back.

One of the reasons it keeps coming back is because the person’s knee has a lot of damage. Here is an example of an email I will get:

Hello Dr Darrow. I have been having pain in my knee. I have been to several doctors and have had an MRI. The MRI says I have a torn meniscus. This is causing me a lot of pain when I walk. A few months ago, I had a cortisone injection in my knee. For a while, my knee felt great. But now that pain is back. I have been told to consider a meniscus surgery by one doctor and a  full knee replacement by another. I also has a Baker’s cyst that has now grown much larger and it causing me great discomfort. I have been told I can drain it, but it will just keep coming back.

What is a Baker’s Cyst
In the knee, between the thigh bone and the shin bone, is the synovial sac. Filled with a thick (synovial) fluid, the synovial sac acts as a shock absorber, protecting the knee from excessive wear and damage. A Baker’s cyst (also referred to as a Popliteal cyst – simply meaning “back of the knee” cyst) develops when the knee becomes weakened through meniscal (cartilage tear) or developing arthritis. As inflammation in the knee develops, fluid collects; the synovial sac expands and pushes its way into the back of the knee. The characteristic bulge of the cyst is easy to identify and depending on the discomfort or pressure a treatment is recommended. Treating the symptoms and not the cause.

In our chronic pain center we see many recurring cases of Baker’s cysts.

It is important to understand that our treatment for Baker’s cyst is to treat the problems of the knee that is causing the Baker’s cyst whether it is Meniscus tears, knee osteoarthritis, or knee instability. However, the Baker’s cyst may be a more immediate concern to the patient as it is causing discomfort and needs to be “drained.”

The typical treatment for a Baker’s cyst can range from rest to aspiration. In cases where the cyst is causing pressure on the nerves of the knee or general discomfort, aspiration is performed to drain the fluid. This is usually followed by an anti-inflammatory to bring down swelling. Ironically, it is this very treatment that causes the Cyst to return.

As pointed out, the Baker’s cyst formed as a response to damage in the knee. Aspiration, anti-inflammatories, even arthroscopy to remove portions of damaged cartilage or meniscus suspect in causing the cyst does not fix the problem. When a Baker’s cyst is recurring, that means the knee is trying, through inflammation (swelling) to stabilize the knee. When the swelling is removed, the body’s attempt at fixing the problem is removed. The very cause of the swelling – damage to the soft tissue, a bone on bone situation – is allowed to continue unimpeded. It then becomes only a matter of time before the knee is in advanced osteoarthritic distress and a total knee replacement is called for.

Ultrasound Guidance
A Baker’s Cyst is usually caused by excess fluid from the anterior portion of the knee. When there is no more room for that fluid, it will commonly be pressured to the back of the knee causing the Baker’s Cyst. We can easily remove this fluid under ultrasound guided aspiration. After aspiration of the cyst or fluid from the anterior portion of the knee, there is typically immediate relief and increase in range of motion of the knee joint.

Then we can start treating the knee with PRP or Stem Cell therapy.

PRP and stem cell therapy for knee instability

PRP treatments involve collecting a small amount of your blood and spinning it in a centrifuge to separate the platelets from the red cells. The collected platelets are then injected into the knee to stimulate healing and regeneration.

Stem cell therapy involves the use of bone marrow derived stem cells. These stem cells are also injected into to the joint to stimulate healing and regeneration.

The determination of which treatment is used is made during the initial consultation and physical examination of the knee. Afterwards we discuss with the patient the realistic healing options that these treatment can offer them.

  • PRP and stem cell therapy work similarly to repair loose damaged ligaments which allow the bones of the knee to move in abnormal ways and lead to a grinding that destroys the joint’s cartilage.
  • The treatments also work on the tendon attachments to the bones. This damage allows the muscles of the knee to hyperflex, injuring both the muscle and allowing the joint the abnormal motion that damages the cartilage.

Do you have questions? Ask Dr. Darrow


A leading provider of stem cell therapy, platelet rich plasma and prolotherapy
11645 WILSHIRE BOULEVARD SUITE 120, LOS ANGELES, CA 90025

PHONE: (800) 300-9300 or 310-231-7000

Stem cell and PRP injections for musculoskeletal conditions are not FDA approved. We do not treat disease. We do not offer IV treatments. There are no guarantees that this treatment will help you. Prior to our treatment, seek advice from your medical physician. Neither Dr. Darrow, nor any associate, offer medical advice from this transmission. This information is offered for educational purposes only. The transmission of this information does not create a physician-patient relationship between you and Dr. Darrow or any associate. We do not guarantee the accuracy, completeness, usefulness or adequacy of any resource, information, product, or process available from this transmission. We cannot be responsible for the receipt of your email since spam filters and servers often block their receipt. If you have a medical issue, please call our office. If you have a medical emergency, please call 911.

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