Targeted Muscle Reinnervation After Amputation

TMR was first developed in 2002 to help those with above-elbow or shoulder amputations better control their myoprosthetic limbs. Doctors soon noticed their patients who had TMR surgery reported less phantom limb sensation and suffered fewer neuromas.

How it works: TMR uses microsurgery to reroute the severed nerves from an amputated limb to the nerve branches of a remaining muscle that is no longer needed as a result of the amputation.  By reconnecting the cut nerve to a nerve going to a muscle, the cut nerve is able to regenerate in a more organized way. By giving the nerve “somewhere to go and something to do,” development of a neuroma can be avoided, thus preventing the signaling pain back to the brain. TMR reconnection reduces the chance of a neuroma forming and phantom limb pain developing.

When it is used: This advanced technique is available at Orlando Health Jewett Orthopedic Institute for both upper- and lower-extremity limb loss and can be performed at the time of amputation to prevent phantom pain or can be done to treat chronic pain which has already developed due to a previous amputation.  By restoring continuity to the nerve, TMR reduces the chances of developing PLP, making it easier for amputees to use prosthetics and return to the activities they enjoy.

When performed as part of an amputation, a microsurgeon joins the team, working in tandem to reconnect the severed nerves during one procedure.

Who it helps: More than 185,000 amputations are performed annually in the United States as treatment for an injury, disease or infection. Complications from vascular disease, diabetes and peripheral arterial disease (PAD) account for more than half of all surgical amputations. Another 45 percent are due to trauma.

Candidates for TMR include patients suffering chronic nerve pain post amputation or those slated for amputation who want to prevent phantom limb pain. TMR can be considered for any patient with prior upper- or lower-extremity amputation who experiences phantom limb pain or residual nerve pain, even several years after surgery.

TMR also may allow improved control of an advanced prosthesis called a myoelectric prosthesis. By reassigning the nerves that once controlled the arm and hand, or leg and foot, to a different muscle, TMR surgery provides more opportunity for a myoelectric prosthesis to detect the electrical signal being generated by the patient’s nerves and thus for improved control of their prosthesis with increased movements and intuitive control.