Electric stimulation may help with joint replacement

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Physical therapy following knee replacement surgery is time-consuming and usually very painful.

There may be an easier way for many people, based on a recent clinical trial conducted at Forbes Regional Hospital, Monroeville. Results of the yearlong study were published last week in the journal Orthopedics.

Electrical muscle stimulation is as effective as standard physical therapy in helping patients recover from joint replacement surgery, but without the pain, researchers headed by orthopedic surgeon Michael Levine found. And patients who rehab with the treatment can do it at home.

A neuromuscular stimulator sends electrical impulses to stimulate the nerves in the muscles. They mimic the normal communication between the brain and the muscles via the central nervous system, which was interrupted by injury or surgery, to "retrain" the muscle to function normally again.

EMS devices have been approved by the FDA for use in many types of muscle rehabilitation. They're also used in sport training.

For patients who have had a total knee replacement, the principal target is the quadriceps, the large muscle group on the front of the thigh that is critical for walking, running, jumping and squatting. The quadriceps can lose up to 62 percent of its strength following surgery.

The electrical impulses prompt the muscles to contract. They get worked out more efficiently than in standard physical therapy, with less risk of injury to joints and tendons, Dr. Levine said. The patient feels a tingling from the electric current, but no pain.

"Patients have to bend and straighten their knee, but there's no strength training with weights," Dr. Levine said. "The stimulator basically does everything for you."

For the trial, 35 patients in a control group received standard physical therapy in their homes three times a week for the first two weeks after surgery, followed by four weeks of outpatient physical therapy.

Patients in the study group "didn't see a therapist once they left the hospital," Dr. Levine said. They were instructed on how to use the neuromuscular stimulator and how to perform a series of range-of-motion exercises.

Patients in the electrical stimulation group exercised in the morning and the late afternoon, about 45 minutes each time.

"Based on the current, [the neuromuscular stimulator] can stimulate the muscles to get stronger, or it can stimulate the muscles to relieve pain," Dr. Levine said. "The protocol was to do strengthening exercises in the morning, pain relief in the afternoon."

Patients in both groups had essentially identical results, but those who rehabbed with electrical stimulation enjoyed the experience a lot more, Dr. Levine said.

For many, the stimulator may produce better results than standard physical therapy, because the patients in the control group actually did all the rehabilitation exercises they were supposed to do.

"The hardest part of the process is the rehab," Dr. Levine said. Many patients don't do all the exercises they are supposed to do because it hurts to do them, he said. This reluctance is what motivated him to conduct the clinical trial.

"If they're not going to do the exercises, we have to find another way," he said.

A smaller study conducted by physicians in Colorado in 2011 of patients who'd had total knee replacement surgery found "significant improvement" in the strength of the quadriceps and hamstring muscles after 3 1/2 weeks of EMS.

One of the patients in Dr. Levine's trial was Patricia Brooks, 63, of Forest Hills. She was a nurse at Forbes Regional Hospital and is now retired.

The neuromuscular stimulator caused "minor discomfort" but no real pain, she said.

"You could adjust the current if it was too much," Ms. Brooks said. "As I progressed, I increased the amount of stimulation. I was back to work in six weeks, perfectly fine."

Rehabbing with the electrical stimulator costs less, Dr. Levine said. Devices currently on the market cost about $400, but "there's a brand new one coming out that's really cheap, about $250," he said.

Dr. Levine gave stimulators to the patients in his study group. Normally, patients would have to buy their own or rent one. The cost of purchasing a machine compares favorably with the cost of physical therapy sessions. The standard Medicare reimbursement rate is about $125 per session. For three physical therapy sessions a week for six weeks, the co-payments required by most health insurance plans alone would be more than the cost of a neuromuscular stimulator. Renting one is cheaper still.

"If patients are motivated to use this device, the cost savings are incredible," Dr. Levine said.

Neuromuscular stimulation customarily is used in conjunction with more traditional methods of physical therapy. Most purchasers have been doctors, chiropractors and physical therapists. Patients must have a prescription to purchase EMS devices designed for physical therapy.

Devices used to tone muscles can be purchased without a prescription, but it's important to buy only those approved by the Food and Drug Administration. The FDA has received reports that some of the over-the-counter devices have caused shocks, burns, bruising and skin irritation. Cautions for using an EMS device remain for people with pacemakers and heart defibrillators and pregnant women.

"This isn't for everybody," Dr. Levine cautioned. "There are people who still need physical therapists."


Jack Kelly: jkelly@post-gazette.com or 412-263-1476.


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