Targeted Muscle Reinnervation (TMR) Specialist

What is a targeted muscle reinnervation?

Targeted Muscle Reinnervation (TMR) is a surgical procedure that reroutes the nerves for people who have had an arm or leg amputation. During TMR, Dr. Echo eliminates or prevents chaotic nerve growth by reconnecting severed peripheral nerves to motor nerves that enter muscles.

TMR was originally created to give patients the ability to control a prosthetic limb with their brain. However, the same procedure also relieves phantom limb pain.

What causes phantom limb pain?

After your amputation, the severed sensory nerves continue to send signals to your brain, which you may feel as phantom pain. Many patients develop a chronic type of pain due to the formation of neuromas.

Neuromas develop at the ends of the nerves as they send out small nerve fibers in search of skin or muscle with which they can communicate. When the nerve growth doesn’t have anywhere to go, it turns into a disorganized ball of nerve and scar tissue called a neuroma.

Some of these neuromas become hypersensitive. When they’re pressed or touched, they cause phantom limb pain; phantom limb sensations; or intense, electrical pain.

The pain caused by neuromas can be so debilitating that it stops you from participating in physical therapy, going to work, wearing a prosthetic limb, or simply engaging in daily activities. 

How does targeted muscle reinnervation alleviate phantom limb pain?

After conducting extensive diagnostic procedures to target the exact nerves and neuromas causing your pain, Dr. Echo performs TMR to connect the painful nerves with nearby motor nerves.

Your surgery creates a new neural circuit that sends the pain signals into the muscles. As a result, your phantom limb pain is diminished or eliminated in some cases. This procedure is very successful, but it can take up to 6 months to see the maximal benefits of the surgery.

Dr. Echo takes a multidisciplinary approach to help patients get relief from phantom limb pain. He works closely with you and your current medical team, including your prosthetists, pain management physicians, and PM&R physicians.

How does targeted muscle reinnervation lead to prosthesis control?

For patients with finger, hand, or arm amputations, the severed motor nerves can be rerouted to the remaining muscle groups in that extremity to create an electrical signal for your prosthetic. This is mainly performed on the upper extremity at this time. TMR enables brain-controlled movements such as bending your elbow, opening and closing your hand, and twisting your wrist.

When you pair an advanced myoelectric prosthesis with TMR, you can perform more sophisticated movements. Myoelectric prostheses contain sensors that read the new nerve connections created during your TMR surgery, giving you a higher level of functioning and fine motor control.

After you undergo TMR and receive a prosthetic arm, you enter rehabilitation so you can learn how to use your prosthesis, including establishing neuromuscular control and coordinating prosthetic movement.

What other procedures relieve pain or improve prosthetic outcomes?

Dr. Echo specializes in several procedures, including:

Regenerative peripheral nerve interface (RPNI)

This procedure reduces your pain by wrapping the end of a nerve with a small piece of muscle taken from a nearby site. The cut nerve attaches to receptors in the muscle, which deactivates the nerve.

Dr. Echo may perform RPNI when you get your amputation or when the stump is reopened, or he may perform RPNI together with TMR.

Neuroma transection/excision

Though the neuroma is always transected, Dr. Echo may also excise or remove the entire neuroma. He carefully weighs the benefits and risks as excising the neuroma can affect wound healing.

Stump revision

The stump may not heal properly, leading to scars, thin skin, or irregularities that make it hard to fit and use a prosthetic. During a stump revision, Dr. Echo may remove scar tissue, adjust the remaining muscles, or shorten the bone, depending on recommendations from your prosthetist.

To learn if you’re a good candidate for TMR surgery, call Anthony Echo, MD, or schedule an appointment online.