Stanford Medicine Newsletter Updates For the Local Community


Possible alternative to knee replacement

Study looks at using a patient's own stem cells

Jason Dragoo, MD, is conducting a study to see if using a patient's own stem cells to treat osteoarthritis can avoid knee replacement surgery.


Millions of people worldwide suffer from knee pain due to osteoarthritis, and 62-year-old Al Perez is one of them. He did not want to undergo a knee replacement, as he likes to stay active, and a knee replacement could keep him from participating in sports.

“I started doing some research and learned that Stanford was investigating a cutting-edge approach to treating knee injuries using stem cells,” Perez said. He continued to ask around for an alternative to knee replacement, and “that’s when I heard about Dr. Dragoo.”

Jason L. Dragoo, MD, associate professor of orthopaedic surgery at Stanford Medicine, is treating patients in a study that aims to reestablish cartilage, decrease chronic inflammation caused by knee osteoarthritis or both. “After 15 years of laboratory research, we have optimized our ability to harvest stem cells from the body and can unleash their potential to improve patients with conditions such as osteoarthritis. After all of this time in the laboratory, we are finally ready for human clinical trials to begin,” Dragoo said with a smile.

The treatment is truly groundbreaking: It uses the patient’s own stem cells harvested from the osteoarthritic knee at the time of surgery. The cells are processed in the operating room and injected back into the knee after the joint is prepared, allowing for repair of the damaged tissue. “We believe this technique will yield more positive results than standard arthroscopy because we are using cell therapy to help the body heal itself,” Dragoo said. “We hope this may save many patients from having to undergo knee replacement.”

Perez signed up for the clinical trial, and in December 2016 he underwent a 90-minute outpatient surgery. Dragoo first removed some fat from the knee using minimally invasive arthroscopic surgery, then performed standard removal of debris from the knee, and finally processed the fat in the operating room to concentrate the stem cells. The cells were injected back into the patient’s knee, and the patient was sent home, able to move the joint immediately. He started physical therapy the next day.

Perez is one of 100 patients who are expected to undergo the procedure. The trial surgeries started at Stanford in the summer of 2016 and are being performed at other national medical centers such as Harvard University, Rush University in Chicago and Ohio State University. After 100 patients have completed the procedure, the researchers will start evaluating whether those who received the stem cell treatments are better off than those who received the standard treatments. “Although extensive laboratory research shows the procedure works, human clinical trials must prove its efficacy,” Dragoo said.

The results of the study are expected to become available in late 2018, and Dragoo is optimistic that stem cell procedures will be routinely used by 2020.

Perez said he was happy with the result. “My knee is feeling great,” he said. “I’m water skiing and playing 18 holes of golf. So far, so good.” Dragoo added, “Overall, patients have been doing really well and appear to be progressing back to a higher level of exercise with less pain.”

The trial is open to people ages 35 to 70 who have osteoarthritis and have experienced knee pain for less than six months. For more information, contact study coordinator Michelle Backer at Additional information on Dragoo’s stem cell trials is available at

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