Surgeons at WVU Medicine have performed the state’s first target muscle reinnervation (TMR) procedure, a technique that transfers residual nerves from an amputated limb into new muscle, allowing patients to control new bioelectric prosthetics.

“TMR allows us to use muscles that no longer function due to the amputation of a limb and reconnect them with existing nerves to create a bioelectric signal to flex the arm or squeeze the hand of a prosthetic,” Jack Gelman, MD, WVU Medicine plastic surgery associate program director, said. “This makes the use of prosthetics very intuitive, because the same nerves that were used to operate the patient’s arm are being used to operate the prosthesis.”

In addition to allowing patients to use more functional prosthetics, targeted muscle reinnervation can be used to treat pain from phantom limb and neuromas, a painful formation of scar tissue at the end of a nerve. By creating a pathway for the nerves in the reinnervated muscle, it is less likely that they will develop painful scar tissue, a common problem for patients who have had amputations.

“This procedure requires a multidisciplinary approach,” Dr. Gelman said. “We are working with physical and occupational therapists, prosthetists, orthopaedic surgeons, neurosurgeons, and other specialists to make this possible for our patients.”

The procedure can be performed either during the original amputation or at a later time, in order to improve functionality and reduce pain.

“This technology is evolving and getting better,” Gelman said. “We are able to provide patients with prosthetics that look and move more like natural limbs, allowing for better grip in hands and a more natural stride when walking.”

According to Gelman, researchers are developing prosthetics that not only restore functionality but allow the patient to feel. These prosthetics will relay nerve signals either through electrodes or wireless technology.

“The field of myoelectric prosthesis control is constantly developing,” Gelman said. “Targeted muscle reinnervation can allow us to improve the quality of life for these patients, not only through the use of these new prosthetics, but by alleviating the pain they experience.”