Cutting edge: Surgeon uses stem cell surgery on stem cell researcher Neil Riordan PhD

Wise County Messenger
By Bob Buckel | Published Wednesday, July 31, 2013

A middle-aged man named Neil got his knee “scoped” in a Decatur operating room recently.

That’s not unusual. Wise Regional Health System’s OR is a busy place, and arthroscopic knee surgery is a common procedure.

But this particular knee had an interesting twist.

Wade McKenna MD and Neil Riordan PhD in OR

IN THE OR – Dr. Wade McKenna performs stem cell surgery on stem cell researcher Neil Riordan PhD.

The physician doing the surgery, Dr. Wade McKenna, met his patient when they shared a podium at a medical conference in February. The patient, Neil Riordan, has a Ph.D. in molecular biology and is one of the leading stem cell researchers in the world.

Riordan’s surgery, a fairly routine cleanout, ended with the insertion of a concentrate of his own stem cells back into the knee, to promote healing, foster cartilage regeneration, and reduce inflammation and the possibility of infection.

It’s a procedure Dr. McKenna has done more than 1,500 times, right here in Decatur, for a variety of fractures, cartilage and tendon injuries. Last year he operated on patients from four countries.

“It’s been mostly in the last three years, and really, the bulk of those in the last year,” he said. “It’s not like I have a newspaper ad that says ‘Stem Cell Surgeon.’ It’s just, you do a patient whose doctor calls you, and that doctor has a family member that he calls you about. Almost all these patients know someone I’ve already taken care of.”

He cited a doctor in Oklahoma who flew his wife down for knee surgery, and a radiologist who reviewed before and after MRIs of one of his procedures and saw actual cartilage growth.

“He calls me on the phone and says, “How did you do that? I’ve never seen condromilatia going the other direction. I’ve only seen it get worse.’” McKenna said. “He ends up sending his father-in-law, who’s from Canada, down to have the surgery. And that guy from Canada goes back and tells… so that’s how it’s happened.”

The surgeries are mostly routine – but the addition of bone marrow-derived stem cells afterward is a game-changer.

“Stem cells change the environment for healing in the joint,” Dr. McKenna said. “It’s like finding the light switch in a dark room. It looks like stem cells are the sentinel cells, the messenger cell – the light switch.

“It makes a substantial difference,” he added.

The journey that brought Neil Riordan to an operating table in Decatur started in Florida.

In February, at the International Stem Cell Society Conference in Fort Lauderdale, he spoke about research he’s doing in Panama that involves taking stem cells from a patient’s own fat, drying them, multiplying them and re-injecting them into the patient to promote healing.

McKenna spoke later about the technique he’s using. His method caught the researcher’s interest in part because it’s one of the few stem cell applications that’s legal in the U.S.

After he presented his results – broken clavicles to ankles to shoulders to arthritic knees – Riordan was interested enough to invite McKenna to dinner.

“He said he wanted to talk to me about some of the clinical experience I’ve had,” McKenna said. “He had not, to that point, been exposed to anyone who had that much experience with bone marrow-derived stem cells.”

Since then, they’ve gotten together several times – Riordan lives in Dallas and has a lab in Farmer’s Branch – and have “gone through a lot of research together,” McKenna said.

And somewhere in there, Riordan decided he might be a candidate for McKenna’s procedure.


“Neil saw all these films I’d taken and thought, ‘I’m ignoring a bunch of loose stuff floating around in my knee.’” McKenna said.

“It was only a couple of weeks ago – we’d been looking at a lot of cell cultures, and spending a lot of time in the lab in Dallas, and he finally just said, ‘Examine me. Put your hand here.’”

It was quickly obvious to the experienced surgeon that his research partner needed some work.

“I thought, ‘What are you doing?’” McKenna said. “He’s got locking, catching, giving way. I tell people all the time, you can ignore pain and swelling, but you can’t ignore mechanical symptoms. If something’s getting caught in your knee, it makes pretty intuitive sense to take that out, and your knee will feel better.”

To that point, Riordan’s focus had been simply on the application of stem cells – not combining it with surgery to clean out the joint and improve its mechanical function. Visiting with the surgeon, it made sense to combine the procedures.

Riordan himself explained it in an interview prior to his surgery.

“I still have stem cells in my bone marrow,” he said. “He’s going to pull some of those out and put them in the knee, the place where they’re needed.”

Riordan said the idea is to help the knee heal like it would have when he was much younger.

“When you’re young, you have a whole bunch of stem cells,” he said. “All we’re doing is just putting more of them in the right place at the right time to help people get over stuff. That’s what it boils down to.”

Riordan’s torn ACL, meniscus damage, adhesions and other knee problems were the result of an injury in 2002 where his knee swelled up, then “kind of” got better, McKenna said.

In surgery, to the constant beeping of the heart monitor and the ree-ree-ree of the pedal-operated instrument shaving off debris and vacuuming it out, the surgeon narrated while he operated.

“Just getting all the junk out of your knee, while it doesn’t give you a new knee, it certainly turns back the hands of time a little bit,” McKenna said. “He was just walking around, doing everything on this without seeking treatment.”

Fluid circulated through the knee and everyone watched the instruments on multiple big-screen television monitors in the OR.

“It didn’t make a lot of sense to start squirting stem cells into his knee until you clean it out a little bit,” McKenna said. “Even with the greatest stem cells in the world, if you just squirt it into that crummy knee with all that loose junk – none of that was going away.

“At least now, you see the difference in the joint. This has a chance of healing.”

After trimming for over an hour, removing frayed cartilage, bone spurs and adhesions, McKenna was ready to inject the bone-marrow aspirate that had been spinning just a few feet away.


Prior to going into the knee, McKenna harvested bone marrow from Riordan’s left hip-bone and delivered it to a technician who put it into a specially-designed centrifuge.

Using the patient’s own stem cells makes the surgery legal in the U.S. Concentrating the bone marrow with a centrifuge makes it much more effective, based on the results McKenna has observed.

“A lot of doctors, when I say we’re doing bone marrow draws, they say there’s no stem cells in an adult,” he said. “That’s just not true. We’ve done the cell counts. I get over a million cells out of this harvest.”

He said the injection of stem cells accomplishes the same thing as microfracture – cracking the joint surface to bring bone marrow to the surface. It just does it better.

“In my mind, it’s not a big leap of faith to think that if a couple of drops of bone marrow from a worn-out knee help it heal, what would the equivalent of 110 ccs of spun-down, concentrated bone marrow with only the best parts do?

“That’s how we invented this surgery. No one had ever done microfracture surgery with bone marrow spread, and we did that in Decatur about five years ago.”

McKenna said the bone marrow from the ileac crest – the hip-bone – has more stem cells and growth factors than what’s in the knee – or on the market.

“There’s a patch that has about 60,000 donor stem cells and you can use that to help tendons heal,” he said. “But would you rather have 60,000 donor stem cells from someone else, that only have a viability of about 75 to 80 percent, or would you rather have 1 to 2 or 3 million of your own stem cells, with a viability of over 90 percent, that were taken at the time?

“They haven’t been freeze-dried, they haven’t been processed, they’re not from someone else – they’re yours. It’s a no brainer.”

“And the stem cells are delivered in a ‘slurry’ of concentrated growth factor,” he said.

“Now we’re on the right track, because the trophic factors are how you heal anyway. It’s how tendon heals, muscle heals, it’s how the body grows cartilage, grows tissue. It’s what stimulates growth and healing.

“We’re not doing anything abnormal,” he added. “This is the body’s normal physiology and reaction to disease. All we’re doing is adding a little gas to the engine.”


Riordan, who has written more than 60 articles and chapters in two textbooks, speaks all over the world about stem cell therapy.

His research in Panama focuses on amniotic stem cells, taken from the “afterbirth” – the umbilical cord and amniotic sac – which would normally be disposed of after a baby is born.

“The amniotic membrane is actually what covers the baby in the womb, and that is what we use,” Riordan said. “There are 120-200 million stem cells inside of an amniotic membrane. They help in healing, decrease inflammation, decreasing adhesion formations, which is a real problem in surgery, particularly spine surgery. They promote and stimulate regeneration.”

Riordan’s clinic, Medistem Panama, is in an area just outside of Panama City called the City of Knowledge. Several major universities and research labs have located facilities there because of tax incentives and relaxed regulation.

Both stressed that the research in Panama uses amniotic tissue – not fetal tissue. Most stem-cell researchers reject the use of fetal tissue both for ethical reasons and because they’re simply not needed.

“The big political uproar about stem cell research is misguided,” he said. “Nobody is using fetal tissue. The only tissue that’s used is either the patient’s own tissue, or, better, amniotic tissue. That amniotic membrane is a very rich source of mesenchymal stem cells. That’s where a lot of Neil’s research is now.”

Riordan believes the FDA’s regulation of stem cells is misguided.

Speaking at a conference last July in Arizona, he said the FDA needs to view stem cells as what they are – human tissue – not a drug. He pointed out that hearts, lungs, kidneys, corneas, skin and other organs are transplanted in the U.S. every day, all without FDA approval.

“The drugs that suppress your immune system so you can receive that heart and survive – those are FDA approved, but the transplant isn’t,” he said. “It’s a procedure. It’s exempt.”

“I think ultimately these (stem cells) should be exempt as well, and should fall under the practice of medicine. That’s my opinion.”

For now, McKenna’s groundbreaking use of stem cells continues to pile up impressive results, providing clinical backup for the research done by people like Riordan.

And every day, it becomes more obvious that the use of stem cells holds the potential for healing across the entire spectrum of human suffering.

“Now, it’s not only about keeping your cartilage from wearing out, it’s about, ‘Can we grow cartilage and help you heal the joint?’” McKenna said. “The answer to that right now is yes-ish. In the not-too-distant future, the answer is yes.”

“It’s an exciting field,” Riordan said.