Medical technology has advanced significantly since the days of the American Civil War, where a gunshot more often than not meant death for the soldier. Now, doctors are able to replace muscle destroyed from explosion by growing new muscle with the help of animal tissue.
Dr. Peter Rubin of the University of Pittsburgh Medical Center is leading a study, in which he is learning how to use tissue from a pig to regrow muscles on limbs. Sgt. Ron Strang, a Marine, is one of the first beneficiaries of such a procedure.
A roadside bomb ripped away part of Sgt. Strang's left thigh a couple of years ago in Afghanistan. Afterwards, he wasn't sure if he would ever be able to walk normally again.
Initially after a number of surgeries Strang — with a divot in his upper thigh — could only walk awkwardly. He was able to move his leg backward. But, because most of the quadriceps muscle was missing from his thigh, he was unable to kick the leg forward. That was about two years ago.
Last Fall Dr. Rubin removed all the scar tissue and stitched in a sheet of tissue from a pig's urinary bladder. Now Sgt. Strang is able to run and jump. He is even thinking of becoming a police officer as a post-military career.
Sgt. Strang is one of the first test cases of what will be an 80 person trial for the growth of limb muscle with the help of animal tissue. The study is financed by the Defense Department's Office of Technology Transition.
The sheet of tissue, called an extracellular matrix, consists of collagen and other proteins and provides a framework for humans to grow new muscle cells. The matrix is attached to healthy muscle and promotes an immune response strong enough to encourage new tissue growth but not so great that the matrix is rejected by the body.
After Dr. Ruben sewed the pig tissue into Sgt. Strang's remaining healthy thigh muscle, his body began to break down the matrix. As the matrix broke down into simpler compounds, the immune system signaled stem cells to come to the site where they could become muscle cells.
The divot in Strang's leg still exists, but the little amount of muscle grown makes a huge difference.
“It was amazing,” Strang told the New York Times. “Right off the bat I could do a full stride, I could bend my knee, kick it out a little bit, just enough to get that initial spring where gravity would take it the rest of the way.”