I hear about “stem cells.” Do they work? Can it save my knee? | Advanced Orthopaedic Specialists | Fayetteville, AR | Rogers, AR
Advanced Orthopaedic Specialists

December 10, 2018

| Christopher Arnold, MD

I hear about “stem cells.” Do they work? Can it save my knee?

The promise of stem cells isn’t necessarily new. Academics have been studying them for more than 20 years. But starting in the last decade, cell therapy pioneers have taken them out of the lab and begun to use them for various health conditions. Accumulating data suggests that stem cell injections are an effective way to treat joint pain and injury including arthritic knees, torn ACLs and rotator cuffs, and more.

As you hear more about this type of non-surgical treatment, you may have a growing list of questions. It’s good to be informed, and as a practice that has carefully studied and has performs stem cell injections on a regular basis, we want to help answer some of the most common questions.

What exactly are stem cells?

Stem cells are cells that are capable of differentiating or changing into other cells. In the knee, the hope is that these cells will develop into cartilage and improve the arthritic knee.

Are there different types of stem cells?

Yes, stem cells are currently available in the United States from three different sources, and we’d like to be clear on each:

1. Amniotic (from the placenta)

  • Commonly used by providers not familiar with cell therapy
  • Are not FDA approved for joint injections
  • Are not living cells
  • There are no studies supporting these for joint injuries
  • Advanced Orthopaedic Specialists does not use these

2. Adipose (from fat)

  • Have a high concentration of stem cells
  • Are not FDA approved for joint injections
  • Advanced Orthopaedic Specialists does not use these

3. Bone marrow aspirate

  • These have living stem cells in addition to a large concentration of growth factors
  • They are FDA approved
  • There are multiple studies supporting their use in joints
  • Advanced Orthopaedic Specialists offers these


Will stem cells grow new cartilage?

Studies show that stem cells won’t restore the cartilage to normal, nor make an arthritic knee normal. However, studies do show they can slow down the progression of arthritis and make the remaining cartilage less likely to deteriorate.

If stem cells don’t grow new cartilage, then how do they work?

Bone marrow aspirate has not only stem cells, but also a variety of growth factors that create a healthier joint. In every joint there are two types of growth factors. Some that build it up (anabolic growth factors) and some that tear it down (catabolic growth factors). A normal joint has a high concentration of anabolic, and a low concentration of catabolic growth factors. An arthritic joint has the opposite (high catabolic and low anabolic). Once a joint experiences injury, the catabolic growth factors become predominate and destruction ensues. When bone marrow aspirate is injected into the joint, the hope is to reverse this destruction and create a healthier joint.

I see so many providers advertising stem cells. How do I know who to choose?

Because this is still a fairly new treatment, it is not covered by insurance. That means patients have to pay cash for this service. Unfortunately, there are some providers out there who are taking advantage of patients for financial gain at their patients’ expense. In addition, they may be using non-FDA approved treatments on patients who are not even candidates for this service. If you elect to have stem cell injections, make sure you have them performed by a physician who uses FDA-approved injections, and confirm that you truly are a candidate before spending the money.

How do I know if I’m a candidate for stem cells?

To be a proper candidate, studies show you must:

  • Not have bone-on-bone contact on your X-ray
  • Not be obese
  • Not smoke
  • Not had any meniscus tears removed
  • Be in general good health


Are these injections better than cortisone?

There are two types of injections. One that helps with the pain, but does not improve the joint (cortisone, Toradol, and viscosupplementation). The other helps with pain, but also makes a healthier joint (PRP and bone marrow aspirate). So, while cortisone can be a great treatment to manage pain, it does not ultimately improve the joint.

What is PRP?

Platelet Rich Plasma (PRP) contains growth factors, but no stem cells. Studies show it can be better than viscosupplementation, but not as good as bone marrow.

How and where do I get a PRP?

The patient has blood drawn from the arm in the office, then the platelets are separated out with a centrifuge, then injected into the joint. Platelets have a high concentration of good growth factors that facilitate healing and decrease inflammation.

How and where do I get a bone marrow aspirate?

An orthopedic surgeon aspirates bone marrow from the patient in the office under local anesthesia (he injects the pelvis with lidocaine). Once the cells are retrieved, they are injected into the joint under ultrasound. The patient takes a pain pill and valium 30 minutes before the procedure. After the procedure they are given crutches for 3-5 days. In one week, they walk normally. No heavy impact activities for 6 weeks.

How do I learn more about this procedure?

Advanced Orthopedic Specialists offers regular, free seminars with our board-certified surgeons to provide you with medically accurate information and to help you understand your options. Sign up to get notified about our next session.

If you’d like a private consultation with one of our specialists, schedule an appointment by calling us at 479-966-4187 or contact us online.

Written by Dr. Christopher Arnold