Phantom limb syndrome and resulting pain are very real things for many amputees. However, a relatively new procedure can ease these and other issues for patients.
Targeted muscle reinnervation (TMR) is a surgical procedure first performed in the early 2000s that was initially developed for patients with shoulder disarticulations or transhumeral amputations. The goal of this procedure was to improve intuitive control of upper-limb prostheses. After the initial procedures were completed, improved control of the upper limb prostheses was demonstrated, along with an improvement in neuroma-related pain and a decrease in phantom-limb pain (the brain’s perception of pain and discomfort seemingly originating in the absent limb) and residual limb pain. With these findings, targeted muscle reinnervation has expanded to become a surgical technique offered for both upper and lower extremity amputations.
Tricking the Brain now or Later
“TMR connects amputated nerves to nerve branches of a nearby muscle group, creating new connections and giving those previously disconnected signals somewhere to go. It tricks the brain into thinking that the amputated part is still there because the nerve that was going to that part has something to do again” (Targeted, 2022).
This surgical technique can be performed at the initial time of amputation as a preventative measure or months to years after an amputation. If the procedure is done at a later date, the patient may need to go without your prosthesis for up to six weeks, or until the surgical wounds heal. The pain from surgery will typically go away within six weeks; however, it can take three to six months for phantom limb pain and neuroma pain to decrease.
Targeted Muscle Reinnervation Proven to Reduce Pain
One study evaluated twenty-two below-knee amputees who underwent targeted muscle reinnervation as outpatients for one year. They were evaluated for symptoms of neuroma or phantom limb pain, patient satisfaction, and functionality, and all twenty-two subjects denied neuroma pain following the amputation. The majority reported phantom limb pain at one month, however, at three months all patients reported resolution of this pain (Bowen, 2019).
Multiple studies report similar findings for this procedure. While most studies use fairly small samples, the studies have collectively found similar results from this procedure. In other “blind” studies where patients were randomly selected to receive the standard-of-care versus TMR and not told which they received, 67% of the patients who received TMR, reported mild or no pain in their limbs, compared to only 27% of patients who received the standard of care. Six of the fourteen patients who received standard-of-care treatment have subsequently crossed over to receive the TMR procedure and have shown improvement in their symptoms of pain and phantoms (Dumanian, 2018).
Targeted muscle reinnervation is more commonly performed at the initial amputation procedure as a preventative measure to avoid formation of neuromas later down the road and decrease the presence of phantom limb sensations/pain long-term.
The Benefits of TMR are No Phantom
If you are an amputee experiencing complications with neuromas, residual limb and phantom limb pain, targeted muscle reinnervation may help relieve some of this discomfort. Socket fit is critical when it comes to neuromas and limb complications, so contact Tillges if you are experiencing any of these issues. Every individual is different, but we partner with a team of doctors who will determine if you are a good candidate for this procedure.
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RESOURCES
- Bowen, JB., Ruter, D., Wee, C., West, J., Valerio, IL. (2019, Jan.) Targeted Muscle Reinnervation Technique in Below-Knee Amputation. Plastic Reconstructive Surgery, 143(1), 309-312.
- Dumanian, G. (2018, Dec. 27). Neuroma/targeted Muscle Reinnervation Educational Highlight. Congressionally Directed Medical Research Programs.
- Targeted Muscle Reinnervation. (2022). Los Angeles Nerve Institute.