Success Story: Targeted Muscle Reinnervation TMR

TMR Surgery, Therapy and Prosthetics: Synchronizing Success
By Miki Fairley

Content provided by The O&P EDGE

On October 2, 2008, Hank Esmond of Bluffton, Indiana, an electrical lineman for Bluffton Utilities, was atop a utility pole when a surge of 7,200 volts of electricity shot through his body, causing extensive burns that resulted in 17 surgeries and the loss of both arms. Esmond, determined to regain his independence, was fiercely dedicated to his rehabilitation process, which included pioneering surgery, as well as advanced occupational therapy techniques and prosthetic technology.

Esmond was flown to the St. Joseph Hospital Burn Center in Ft. Wayne, where he spent about a month and a half. During most of that time, he was in a medically induced coma, according to a September, 2009, article in Ft. Wayne-based Business People. Mercifully, Esmond has no recollection of the accident.

“In addition to fatalities, major high-voltage electrical trauma can produce devastating physical injuries,” notes a health-and-safety fact sheet from the Energy Recovery Council. “Repeated removal of tissue, amputations and extensive rehabilitation are common…. It is not unusual for treatment to require tissue removal over several days, and frequently the damage becomes significant enough to warrant amputation.” Once the outer layer of skin is destroyed, large currents can pass through it and produce tissue damage, especially to skeletal muscle and nerves; healthy skin and fat often conceal injured muscles, nerves, and bone as well. “Thus, it is very difficult to accurately diagnose and localize tissue damage scattered throughout the current path before irreversible cell damage has occurred,” the fact sheet says. It adds that it typically takes one to three days before the true extent of the damage can be recognized. This accurately describes what happened to Esmond. After a series of surgeries, Esmond ended up with a left shoulder disarticulation and a right transhumeral amputation.

Leading-edge techniques and technologies have converged in Esmond’s rehabilitation care, including targeted muscle reinnervation (TMR) surgery, Otto Bock’s DynamicArm TMR thought-controlled prosthesis, innovative occupational therapy and new prosthetic-fitting techniques.

Esmond’s groundbreaking team and the challenges they are meeting provide a dramatic picture of the new wave of rehabilitation care for persons with amputations. However, a key to successful rehabilitation is the patient—and Esmond’s strong motivation and ability to learn quickly have won the admiration of his rehab team. Brooke O’Steen, OTR/L, has worked with Esmond since the beginning of his recovery and rehabilitation journey. In describing Esmond, O’Steen simply says, “He’s awesome!”

Pat Prigge, CP, recalls a story that epitomizes Esmond’s determination and intelligence. Prigge, who is the clinical upper-extremity specialist at Advanced Arm Dynamics (AAD) of the Midwest, Waterloo, Iowa, has been working with Sam Santa-Rita, CP, LP, owner of Superior Rehabilitation Techniques (SRT), based in Ft. Wayne, on Esmond’s prosthetic care. “When we were teaching him how to operate his prosthesis for his transhumeral side, we told him it would take a little time to learn since we needed to use a very complicated control method to make it work. I told him, ‘Don’t expect to be able to pick up a paper cup today—that’s going to come in time.’ Well, while I was talking to his therapist, Hank comes back over and hands me a paper cup!”

As part of field trials, Esmond was fitted with the beta version of Otto Bock’s DynamicArm TMR on his shoulder-disarticulation side. The prosthesis, especially designed to take advantage of the more intuitive control options provided by TMR surgery, can handle up to eight myoelectric inputs. Esmond uses a conventional myoelectric prosthesis on his transhumeral side. In February, he was fitted with one of the first two commercial models of the prosthesis. The control programs are totally different for his left and right sides, O’Steen notes. “He’s had to learn to operate them simultaneously for bimanual tasks, and he’s done amazingly well.”

“He’s doing something [with his right-side prosthesis] that most patients probably wouldn’t tolerate,” Prigge says. “He’s running a full electric system with a single electrode, a second input site and a linear transducer. That’s complicated in itself, but he’s doing really well.” Prigge adds, “The reinnervation surgery and the more intuitive control pattern with his shoulder disarticulation side should help him better supplement what he is already doing with the right side.” The fact that Esmond is almost ambidextrous—he eats and writes with his left hand, but plays sports right-handed—may also contribute to his unusual success in using bilateral prostheses.

The DynamicArm TMR can utilize up to eight myoelectric inputs; Esmond’s recently fit prosthesis is currently programmed to access four sites, and as he gains more accurate control of other muscle sites, a fifth and then a sixth site will be added into the program.

“The four-site system is a stepping stone to where we want to go,” Prigge explains. “He’s got strong, successful reinnervated sites, but it takes time to learn how to access those muscles.” The six essential movements are elbow flexion/extension; wrist supination/pronation, and hand open/close. By merely thinking about it, Esmond can now flex or extend his elbow while opening or closing his hand. He also can control wrist pronation/supination by utilizing a switch over the top of his shoulder—movements that will be controlled simply by thought once he is able to fully use his fifth and sixth myoelectric input sites.

Prigge likens these cutting-edge rehabilitation advances to a cascade, rather than a convergence. “The TMR surgery seems to have been first, then manufacturers stepped up and created new products to utilize the new signal sites. Now fitting techniques need to be modified to adapt to the new technology. It’s a whole cascade of things building up into something new and unique, with a whole slew of new challenges. We’ve got to do things we’ve never done before.”