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SA Docs Using Stem Cell Injections To Target Knee Pain

Wendy Rigby
Texas Public Radio
An experimental stem cell treatment for knee pain is injected into the patients leg.

Knee pain caused by osteoarthritis is one of the most common orthopedic health problems in the country. Now, some San Antonio physicians are embarking on a clinical trial of a new approach to healing using people’s own stem cells.


Esther Salinas of San Antonio has learned to live with the bone on bone discomfort of osteoarthritis. It’s a health problem often brought on by age, overuse or obesity.

Credit Wendy Rigby / Texas Public Radio
Physicians use ultrasound to help guide the needle to the right location for injection of the regenerative cells.


"Steroid injections? It’s just a temporary fix," Salinas said. "You know, you just deal with it."

Salinas is part of a Food and Drug Administration pivotal trial to see if injections of her own stem cells into her knee will ease her pain.

The experimental procedure starts with liposuction.

Plastic and Reconstructive surgeon Jaime Garza, MD, harvests fat from the lower abdomen or the inner thigh. It takes a container of fat about the size of a stick of butter to get enough regenerative cells to inject back into the knee. They’re called adipose-derived stem cells.

Credit Wendy Rigby / Texas Public Radio
Daniel Santa Maria, MD, (left) and Jaime Garza, MD (right).


"These are the cells that live around blood vessels throughout our entire bodies," Garza explained. "These cells are in abundance in fat."

The fat tissue is injected with an enzyme to help break it down, spun down and concentrated. Then, the sample is checked under a microscope to make sure it’s viable with enough live stem cells to be effective. Millions of them.

Within 90 minutes of the sterile processing, the concentrated cells are ready to be injected back into the patient’s knee. The idea is to jumpstart the body’s own healing.

Credit Wendy Rigby / Texas Public Radio
From the time the fat is harvested to the time the regenerative cells are injected into the knee is about 90 minutes.


"We’re using them for what is called immunomodulation," Garza said. "That means affecting your immune system in a positive way. Nobody in their right mind is going to believe that these cells are going to turn into cartilage. But these cells have great signaling capacity. They can come in and scope and send out the right signals so that your body can take over and send the correct cells in to start repairing the damage."

Daniel Santa Maria, MD,  is a Board-Certified Sports Medicine Specialist injecting Salinas. "This treatment and treatments like it serve to be really a paradigm shift for our patients, something that can not only slow down the clock but possibly to an extent beat it back," Santa Maria stated.

Santa Maria uses ultrasound guidance to put the cellular therapy where it needs to go. Salinas says she feels pressure, but no real pain.

"I didn’t even know it was over with," Salinas commented. "Not so bad at all."

Credit Wendy Rigby / Texas Public Radio
Most patients describe a sense of pressure but no real pain during the injections.


Santa Maria said this study provides a scientific approach to a theoretical idea. He said they will ask questions like "How are they doing with pain? How are they doing with function? And even how do their MRIs look before and after the procedure?"

Initially, 40 people are being recruited. Some will get placebo injections, others a low dose and others a high dose of regenerative cells. Garza said early safety trials were encouraging. "It’s literally within two to three days patients just say 'Wow. I feel so much better.'"

No one knows how long the pain relief would last or even how many injections of stem cells people might need. That’s why these kinds of studies are underway.

Current treatments include anti-inflammatory pills, steroids or or injections of hyaluronic acid for lubrication. The last resort is joint replacement surgery, a major operation.

"We as physicians at some point want to say we’re not going to do surgery anymore because now we can fix that problem non-surgically," Garza asserted. "It’s really about patient safety, patient care. And giving somebody some hope for the future."

Credit Wendy Rigby / Texas Public Radio
This is the room where patients have a liposuction procedure to harvest adipose-derived stem cells.


As with any kind of therapy administered through a needle, a risk of infection or pain exists. And there’s also the risk that nothing will happen.

Garza and his colleagues plan a longer term study starting in January under the title Texas Center for Cellular Research and Therapy.