Dr. Robinson Improves Amputation Care through Targeted Muscle Reinnervation (TMR)

What is Targeted Muscle Reinnervation (TMR)?

An amputation is a devastating outcome following a severe limb injury both on and off the job site. Improvements in patient function and pain have made Targeted Muscle Reinnervation (TMR) the most promising technology in amputation medicine since the advent of the myoelectric prosthesis (MP). TMR is essentially the concept of nerve transfers to maximize the number of independently controlled muscles available to control MPs.

How Does TMR Work?

A myoelectric prosthesis (MP) uses electromyography (EMG) sensors to activate electric motor-powered motion. This offers significant advantages over body-powered devices, including more intuitive and precise control, power, comfort, and less fatigue. Because MPs are controlled by EMG signals, the number of motion patterns they can perform is a function of the number of muscles that can be activated by the patient and sensed by the device. TMR involves surgically transferring nerves severed in the amputation process to available, superficial, and redundant muscles. By working with a therapist and a prosthetist, patients can learn to activate these re-innervated muscles and control their MP device, often with greater degrees of control than without TMR.

What are the Benefits of TMR for Amputees?

An exciting secondary outcome of TMR has quickly become a primary benefit: pain relief. It is well-recognized that amputees are often troubled by neuropathic pain including phantom sensations and neuroma. Neuroma pain is one of the most significant limitations of prosthesis wear. In TMR, severed nerves are coapted to a muscle unit, so the axons are provided “something to do” and do not create painful neuroma. TMR surgery is now routinely performed as primary or secondary neuroma management in both upper and lower extremity amputations.

Improving TMR Outcomes

Collaboration between surgeons and prosthetists greatly improves outcomes. On one hand, “cross-pollination” of ideas continues to lead to advances. An example of MP device technology and the surgical technique evolving together is the “Starfish” procedure. This allows independent activation of fingers in transmetacarpal hand amputations by repositioning the deep interosseous muscles of the hand more superficially where they can be picked up by the EMG sensors. 

Another way collaboration improves outcomes is through coordination of care. Many patients with amputations have complex clinical challenges coupled with difficult social and return-to-work adjustments. There has been a trend in establishing dedicated amputee care clinics bringing surgeons, therapists, and prosthetists together face-to-face to lower logistical hurdles for the patient and allow for good communication between care team. Hopefully, this technology and continued advancement will give amputee patients the best chance at maximizing their return to independent life.

About Dr. Elliot Robinson

Dr. Elliot Robinson is one of our board-certified, fellowship-trained hand specialists at OrthoGeorgia. We are thrilled to announce that he is now offering TMR for both upper and lower extremity amputees. Along with performing this highly skilled procedure, he will also be directing monthly Amputee Care Clinics at OrthoGeorgia, which will keep patients informed about their care and help them regain independence both at home and at work. Patients who undergo targeted muscle reinnervation gain improved prosthetic control, improved pain management, and a better quality of life when they can more confidently manage their limb loss. If you have any questions about TMR or the care we provide at OrthoGeorgia, we encourage you to contact the office location nearest you today. Patients can meet with Dr. Robinson at our offices in Macon and Warner Robins.