Targeted Muscle Reinnervation: Ease Chronic Pain After Limb Loss

For many of the 2.1 million people in the U.S. living with an amputation, chronic pain is a part of daily living. As Dr. Aparajit Naram, a plastic surgeon at Baystate Plastic & Reconstructive Surgery, explains, “When a limb is amputated, the nerves endings at the surgical site are no longer connected to their target (hand/foot/leg/arm) which is the source of information that is sent to the brain. However, they still send information to the brain that can lead to painful medical conditions that can impact a patient’s quality of life as well as their ability to function.”

But, as Naram notes, a surgical option known as targeted muscle reinnervation, or TMR for short, has the potential to significantly reduce or eliminate amputation-related nerve pain.

Types of Pain After Amputation 

Amputation pain can arise weeks or months after a limb has been removed. Naram says, “Roughly 60 to 70% of patients experience post-amputation nerve pain in either the form of neuroma pain or phantom limb pain.” While both types of pain can be chronic and limiting, there are differences in their cause and how they are experienced.

Neroma pain

This type of pain develops when the nerve endings in the residual limb—the part remaining post-surgery—attempt to heal through regeneration. But because there’s nowhere for the nerve to to go, you often end up with a ball of nerve tissue directly under the skin referred to as a neuroma.

Naram says, “While every amputation results in the development of a neuroma, not every neuroma is painful. But in the cases where there is pain, it’s often tender to the touch and, when pressed upon either by a hand or a prosthetic, can cause shooting pains along the residual limb. For many people, the pain is severe enough to keep them from wearing their prosthetic or engaging in daily activities.

Phantom Limb Pain (PLP)

Experienced by 45-85% amputees, PLP is pain that the brain perceives is coming from the limb that is no longer there. While the exact cause of this type of pain is unclear, many experts believe it’s a result of mixed signals from the brain. Naram says, “After an amputation, the brain no longer receives signals from the missing limb. The brain recognizes something is different and can interpret it as pain.”

How TMR can help

Considered the most promising treatment for PLP and neuroma pain, TMR was originally developed to improve communications between residual limbs and prosthetics.

Naram explains how it works: “TMR involves connecting two nerves together. The nerve that lost its source of information and its function is connected to another nerve that is going into a muscle nearby. This gives the nerve somewhere to go and something to do. It can be performed at the time of the amputation, which prevents the potential creation of a neuroma, or even years later. After the procedure, nerve regrowth occurs at a rate of one incher per month starting about one month after surgery.”

He adds, “For some patients, pain relief is almost immediate while for others it can take three to nine months. Other benefits of the surgery can include a reduced dependence on medication and better experiences using robotic prosthetics. The results for individuals are variable.”

Is TMR right for you?

To learn if TMR is right for you, contact Baystate Plastic & Reconstructive Surgery to schedule an evaluation: 413-794-5363.

“Our team will assess your specific case,” says Naram, “We’ll want to be sure you’ve exhausted all non-surgical options and have ruled out other causes of pain. The evaluation is easy and regardless of the findings, we’ll do our best to reduce as much pain as possible.”