Targeted Muscle Reinnervation
Targeted muscle reinnervation, or TMR, is a nerve surgery technique that helps to decrease or eliminate nerve and phantom limb pain associated with nerve injuries and amputation. It helps by rerouting injured or amputated nerves to new targets to interrupt the cycle of misguided nerve regeneration. This helps give the nerves a fresh start to hopefully break the cycle of pain and prevent it from starting. The result can be significant pain relief and better prosthetic control. TMR can also be a treatment option for individuals who have nerve pain from other sources besides amputation.
What is targeted muscle reinnervation?
The peripheral nerves in our body have the ability to regenerate. If a nerve is injured, like in the instance of a limb amputation, it will try to grow back. But the nerve is looking for a target that no longer exists. This can create a painful sensation of the nerve trying to find the limb and failing. This is called phantom pain.
Additionally, the attempts of regrowing and failing cause swelling at the end of the nerve, called a neuroma. Neuromas can develop following an amputation as well as other types of injuries. Neuromas cause significant pain. For amputees, neuromas can cause considerable pain when wearing a prosthetic device.
With TMR, surgeons identify the nerve that has been trying to regenerate and create a new connection with a nerve in the area. This gives the misfiring nerve a new purpose and hopefully breaks the painful cycle.
Who can have targeted muscle reinnervation?
TMR is a treatment option for people with phantom limb pain, residual limb pain or pain from a nerve injury that can’t be repaired.
It is generally more effective when done sooner. TMR can be performed at the time of a limb amputation. However, it may also be an option for people who have had chronic pain for years.
What happens during targeted muscle reinnervation surgery?
See Jacob Brubacher, MD, explain the TMR procedure. Warning: Images of surgery are included in this video.
Right now we're seeing on screen, one of my partners, Dr. Brent Wise, who does orthopedic trauma here at KU and you know, this is one of the wonderful things about being at the University of Kansas, where we have such multidisciplinary approach, just as what we find in most patients, sometimes it's not just one thing. So JD was having significant issues with nerve symptoms, but he also had an unstable terminal end of his stump that was causing a lot of mechanical symptoms. So, this is where a team approach with somebody who specializes with microsurgery and nerves, such as myself, and somebody like Dr. Wise, who does a lot of amputee care as well, can really be beneficial. So, you know, this part of the surgery, once Dr. Wise has finished revising the amputation and stabilizing the stump, we're able to find the nerve, and this is pulling out his sciatic nerve, and you see the large bulbous end to the to the nerve, and more normal nerve up above. And that's what we're trying to get back, is to the normal, healthy nerve, because we know the end of the nerve has been trying to regenerate, and it's just full of all these nerve fibers that are really quite confused, trying to find JD’s foot again. But what we do is then transect the nerve higher up away from the site where the prosthetic is going to be, and then we give that a new target. So, we find motor nerves and allow that sciatic nerve to grow into the motor branch of these nerves. And what that does is the sciatic nerve then says, “Ok, this is my new job. I'm no longer going to try to try to find the foot. I'm going to I'm going to innervate the hamstrings musculature.” So, as it starts to grow, then the brain and then through the loop with the spinal cord realize, OK, this is my new job. So, I'm no longer going to continue try to grow back and find the foot, because I have a new task. So that's the concept behind targeted muscle reinnervation.
Benefits and risks of targeted muscle reinnervation
This is a procedure that has shown excellent results in clinical studies and in our patients. All surgical procedures carry risks and will need to be discussed with your surgeon. These procedures are sometimes performed concurrently with an amputation or can be done after the amputation is completed. Additionally, The University of Kansas Health System offers mirror therapy, diagnostic injections, medication management and physical therapy to help treat nerve pain.
Why choose us
Our team includes peripheral nerve microsurgeons, orthopedic trauma specialists, prosthetists and therapists collaborating on a personalized care plan for each patient.
The University of Kansas Health System offers some of the nation’s leading experts in complex surgical procedures. As the region’s premier academic medical center, our dedicated surgeons and staff will ensure you experience the highest quality care possible. Specialty-trained and experienced surgeons use the latest techniques in state-of-the-art facilities to perform complex procedures time and again.