Share This Page

Pitt makes strides in muscle regeneration

| Wednesday, April 30, 2014, 2:46 p.m.
Sean Stipp | Tribune-Review
Physical Therapist Frank Mechling (left) works with Nick Clark, 34, on his balance during a physical therapy session at Oak View Physical Therapy, LLC in Unity on April 30, 2014. Clark is one of five patients who participated in a clinical trial at the University of Pittsburgh. Doctors surgically implanted an extracellular matrix derived from pig bladder. Muscles in his left leg, damaged in a 2005 skiing accident, grew stronger after the procedure. At one point, Clark thought he was never going to walk but now can walk without the help of a cane.
Sean Stipp | Tribune-Review
Nick Clark, 34, works out on a treadmill during a physical therapy session at Oak View Physical Therapy, LLC in Unity on April 30, 2014. Clark is one of five patients who participated in a clinical trial at the University of Pittsburgh. Doctors surgically implanted an extracellular matrix derived from pig bladder. Muscles in his left leg, damaged in a 2005 skiing accident, grew stronger after the procedure. At one point, Clark thought he was never going to walk but now can walk without the help of a cane.
Sean Stipp | Tribune-Review
Nick Clark, 34, stretches his muscles during a physical therapy session with Physical Therapist Frank Mechling at Oak View Physical Therapy, LLC in Unity on April 30, 2014. Clark is one of five patients who participated in a clinical trial at the University of Pittsburgh. Doctors surgically implanted an extracellular matrix derived from pig bladder. Muscles in his left leg, damaged in a 2005 skiing accident, grew stronger after the procedure. At one point, he thought he was never going to walk but now can walk without the help of a cane.
Sean Stipp | Tribune-Review
Nick Clark, 34, works out during a physical therapy session at Oak View Physical Therapy, LLC in Unity on April 30, 2014. Clark is one of five patients who participated in a clinical trial at the University of Pittsburgh. Doctors surgically implanted an extracellular matrix derived from pig bladder. Muscles in his left leg, damaged in a 2005 skiing accident, grew stronger after the procedure. At one point, he thought he was never going to walk but now can walk without the help of a cane.
Sean Stipp | Tribune-Review
Nick Clark, 34, shows his scar where doctors surgically implanted an extracellular matrix derived from pig bladder. Muscles in his left leg, damaged in a 2005 skiing accident, grew stronger after the procedure. At one point, Clark thought he was never going to walk but now can walk without the help of a cane.

In the months after he broke his left leg while skiing, Nick Clark thought he'd never walk again.

His leg twisted as he turned sharply, and Clark lost nearly all the nerves and muscle tissue on one side of his leg.

“It was pretty brutal. I was bed-ridden for a while. I couldn't even roll over in bed,” Clark, 34, said of the 2005 accident at Seven Springs Mountain Resort.

In 2012, Clark enrolled in a clinical trial at the University of Pittsburgh to test an unheard-of approach to regenerate muscle. Doctors implanted in his leg a biological scaffold made from pig bladders to try to stimulate his stem cells to grow into strong, healthy tissue.

It worked.

“It's been a pretty dramatic change. I don't have to use a cane to walk anymore. It's been a big improvement,” said Clark of Greensburg, an applications engineer at Powerex Inc. in Youngwood.

Researchers at Pitt and the McGowan Institute for Regenerative Medicine on Wednesday published preliminary results from the trial involving five patients, including Clark. Doctors said the approach, using a so-called extracellular matrix, dramatically restored function for patients who lost nearly all muscle in parts of their legs.

“The things that you and I take for granted — getting out of a chair, taking steps, stepping off a curb, getting out of a car — these are the types of deficits that these individuals had,” said senior investigator Stephen Badylak, professor of surgery at Pitt and deputy director of the McGowan Institute.

“It's nice to conduct a study where we can show nice, pretty pictures of stem cells, but if it doesn't make a difference for the patients at the end of the day, it's nothing really other than a study. ... These patients got better.”

Three of the five who received the biological scaffold experienced dramatic improvement, growing stronger by 20 percent or more six months later. The two other patients had some improvement and felt better, the researchers report in the journal Science Translational Medicine.

The researchers said the extracellular matrix is not a medical device and cautioned that using it involves a complex process that includes removing scar tissue and placing the material adjacent to healthy tissue so that it can recruit the patient's stem and progenitor cells.

Patients in the study underwent often grueling post-surgery rehabilitation that required them to start physical therapy on the day after the procedure. Doctors designed it that way so that the stem cells would begin to adapt immediately, Badylak said. The therapy lasted up to six months.

Clark, who experienced the most muscle loss among participants, showed remarkable improvement in two tests conducted in the months after the procedure, said Dr. Elke Brown, a clinical researcher in Pitt's department of physical medicine and rehabilitation.

He was able to jump 34.5 inches on his injured leg six months after surgery, compared with 3 inches before the procedure. In addition, he was able to stand on his leg with his eyes closed for 18.5 seconds six months after the surgery, compared with 10 seconds on the day before surgery, Brown said.

“I had extensive nerve damage, so I still have issues,” said Clark, who cannot run and won't ski again.

Doctors for years have used the pig-derived material to repair hernias and help reconstruct breasts after cancer removal. To ensure patient safety, researchers selected patients whose tissue healed to avoid the potential for infection. They purposely picked people who tried and failed at other treatments.

Researchers say the technique could be beneficial not only for thousands of soldiers injured in combat, but for people with severe trauma from car or motorcycle accidents. Three patients in the study had lower leg injuries; two had injuries in the upper leg. All lost between 60 percent and 90 percent of their injured muscle.

People who experience such severe injuries have limited treatment options, said Dr. Peter Rubin, the study's co-investigator and chair of plastic surgery at Pitt. In the past, doctors tried to reroute tendons or move muscle from another part of the body, but those techniques were not always successful, he said.

“While the number of patients was small, we are very encouraged by the data,” Rubin said.

Researchers are recruiting more patients for the trial, which is partly funded with $3 million from the Department of Defense. Other grants came from the Department of the Interior and National Institutes of Health.

Luis Fábregas is Trib Total Media's medical editor. Reach him at 412-320-7998 or lfabregas@tribweb.com.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.