Targeted Muscle Reinnervation (TMR)
Overview
Those who lose a limb often have intense pain that seems to be coming from the part of the body that’s no longer there. Even with daily medicine, drugs can only mask the pain, but not cure it. Pain following amputation affects many patients. It is caused by many factors, but much of it is related to the development of neuromas (disorganized and painful nerve endings) stemming from the trauma or surgery.
When severed nerves send signals to an area that’s no longer there, common side effects can be phantom limb sensations, phantom limb pain or generalized pain in the extremity. Phantom limb pain affects a large percent of amputees.
For the nearly two million Americans who have lost a limb, relearning how to perform simple tasks with a prosthetic takes time and patience. For a lot of amputees, this can be virtually impossible due to constant pain caused by severed nerves.
Targeted Muscle Reinnervation (TMR) brings amputees relief and helps them get back to their daily lives. TMR was initially developed to work with new technology in bio-prosthetic limbs, but surgeons noticed that amputees who had TMR surgery also reported a significant reduction in both neuroma and phantom limb pain.
TMR connects amputated nerves to nerve branches of a nearby muscle group, creating new connections and giving those previously disconnected signals somewhere to go. TMR 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. When TMR was performed at the time of amputation, researchers found that a small percentage of patients reported pain six months later.
Besides reducing pain, new advancements in artificial limbs include sensors that can actually read those new nerve connections created during TMR surgery. It allows amputees to move their prosthetics with more variables.
TMR for arm amputees reassigns nerves, giving an amputee the opportunity to use a prosthesis that allows for elbow, wrist, and hand movements. The procedure is performed differently depending on the type of arm amputation. TMR is paired with extensive rehabilitation enabling the patient to learn how to use the advanced prosthesis.
The goal of TMR for the upper extremity is to achieve a higher level of function and more precise control, especially in upper extremity amputations at the elbow or higher. Coordinating motions such as elbow flexing and hand gripping are possible with TMR.
The treatment of symptomatic neuroma pain after upper or lower extremity amputation has historically been to cut out (resect) the tissues including the nerves. Targeted Muscle Reinnervation (TMR) was developed initially for improved prosthesis control but has since shown promising results in the treatment of neuromas – growths or tumors of nerve tissue. With TMR, the nerves are transferred into small nerve branches of the muscles allowing the amputated nerves the opportunity to connect into the transferred muscle.
Video examples about TMR and prosthetics:
https://newyork.cbslocal.com/2018/12/27/tmr-surgery-for-amputees/
Anatomy
Each time a movement occurs, such as bending the elbow or twisting the wrist, signals go from the brain through the nervous system to the appropriate muscle that then performs the movement. When the arm (specifically the shoulder and below) is amputated, the nerves that once controlled the hand, wrist, and elbow are lost. The nerves damaged in arm amputees include the musculocutaneous nerve (controls upper arm muscles such as the coracobrachialis, biceps and medial brachialis), median nerve (controls the forearm, wrist and hand movement), radial nerve, (controls hand open and wrist-up movements) and ulnar nerve (controls grasping motion).
There are two different types of arm amputations: everything below the shoulder is amputated (shoulder disarticulation amputation) and everything below the top of the elbow is amputated (above-elbow amputation).
Traditionally, most motorized artificial limbs have been controlled by electrical signals (electromyogram-EMG) from pairs of muscles in the amputated limb. This allows for isolated but not coordinated motion.
Description
Targeted Muscle Reinnervation (TMR) is an innovative surgical procedure developed in 2002 by Dr. Gregory Dumanian and Dr. Todd Kuiken, MD, PhD. at Northwestern University, that provides easier, more intuitive prosthesis control for individuals with above-elbow or shoulder amputations. This technology works by reassigning nerves that once controlled the arm and hand, giving an above-elbow or shoulder amputee freedom to control their prosthesis. There are so many nerves and muscles in the body that reassigning one will have little to no effect on daily functions.
With TMR, there are more movements the prosthesis can do: elbow up, elbow down, hand open, hand close, and twist wrist. All these movements are controlled by the brain, thanks to the relocated nerves. In the past, above-elbow and shoulder amputees had significantly less control over their prosthetics and could at most move their elbow up and down. Being fitted with a TMR prosthesis completely changes their lives by giving them more control over their prosthesis and increases their independence.
TMR is best suited for above-elbow and shoulder amputees because they have completely lost all nerves and muscles that control the arm and hand. In the case of below-elbow amputees, they still have some of the muscles and nerves left in their forearm which fire when the brain signals their hand to open or close. These signals enable the prosthetic device to operate with normal brain thoughts.
Besides prosthesis control, TMR is also used to reduce, and sometimes eliminate, pain in patients.

Diagnosis
The diagnostic examination of post-amputation pain can involve a local anesthetic injection to determine the cause of the pain and whether it is neuropathic (nerve-related).
TMR is available for any patient with prior upper or lower extremity amputation.
Rehabilitation
After TMR, the patient can get fitted for a myoelectric-controlled prosthesis – an externally powered artificial limb controlled with the electrical signals generated naturally by your own muscles. Until the prosthesis is ready, the patient can wear their regular prosthesis. To use the prosthesis, the patient will have to go through focused rehabilitation that involves coordinative and neuromuscular training. Rehabilitation teaches patients how to use the prosthesis as well as helps with the healing process.
Next Steps
Surgeons at Florida Orthopaedic Institute are fully trained and skilled in TMR. If you, or someone you know, is a potential candidate for TMR surgery, please make an appointment for a consultation.
Areas of Focus
- Hand & Wrist
- Basal Joint Surgery
- Carpal Tunnel Syndrome
- Colles’ Fractures (Broken Wrist)
- De Quervain's Tenosynovitis
- Dupuytren’s Disease
- Finger Dislocation
- Flexor Tendonitis
- Functional Nerve Transfers of The Hand
- Ganglion Cysts
- Hand & Finger Replantation
- Hand Nerve Decompression
- Hand Skin Grafts
- Nerve Pain
- Peripheral Nerve Surgery (Hand) Revision
- Revascularization of the Hand
- Rheumatoid Arthritis Of The Hand
- Sudden (Acute) Finger, Hand & Wrist Injuries
- Targeted Muscle Reinnervation (TMR)
- Tendon Transfers of The Hand
- Trigger Finger
- Ulnar Neuritis
- WALANT (Wide Awake Local Anesthesia No Tourniquet)
- Wrist Arthroscopy
- Wrist Fractures
- Wrist Sprains
- Wrist Tendonitis
The following Florida Orthopaedic Institute physicians specialize in TMR (Targeted Muscle Reinnervation):
Specialties
- Achilles Tendinitis - Achilles Insertional Calcific Tendinopathy (ACIT)
- Achilles Tendon Rupture
- Achilles Tendonitis
- ACL Injuries
- ALIF: Anterior Lumbar Interbody Fusion Surgery
- Ankle Fracture Surgery
- Ankle Fractures (Broken Ankle)
- Ankle Fusion
- Arthritis & Adult Reconstruction Surgery
- Arthroscopic Chondroplasty
- Arthroscopic Debridement of the Elbow
- Arthroscopic Rotator Cuff Repair
- Artificial Disc Replacement (ADR)
- Aspiration of the Olecranon Bursa
- Avascular Necrosis (Osteonecrosis)
- Back Surgery Types
- Bankart Repair
- Basal Joint Surgery
- Bicep Tendon Tear
- Bicep Tenodesis
- Bioinductive Implant
- Broken Collarbone
- Bunions
- Bursitis of the Shoulder (Subacromial Bursitis)
- Calcific Tendinitis of the Shoulder
- Carpal Tunnel Syndrome
- CARTIVA® Implant For Big Toe Joint Arthritis
- Charcot Joint
- Chiropractic
- Colles’ Fractures (Broken Wrist)
- Community Outreach
- ConforMIS Knee Replacement
- Cubital Tunnel Syndrome
- De Quervain's Tenosynovitis
- Degenerative Disc Disease
- Diffuse Idiopathic Skeletal Hyperostosis (DISH)
- Discitis
- Dislocated Shoulder
- Dupuytren’s Disease
- Elbow
- Elbow Bursitis
- Elbow Injuries in Throwing Athletes
- Epidural Injections for Spinal Pain
- Finger Dislocation
- Flexor Tendonitis
- Foot, Ankle & Lower Leg
- Fractures Of The Shoulder Blade (Scapula)
- Fractures Of The Tibial Spine
- Functional Nerve Transfers of The Hand
- Ganglion Cysts
- General Orthopedics
- Glenoid Labrum Tear
- Golfer's Elbow
- Growth Plate Injuries Of The Elbow
- Hallux Rigidus - Cheilectomy
- Hand & Finger Replantation
- Hand & Upper Extremity
- Hand & Wrist
- Hand Nerve Decompression
- Hand Skin Grafts
- Hip & Thigh
- Hip Arthroscopy
- Hip Dislocation
- Hip Flexor Strains
- Hip Fractures
- Hip Hemiarthroplasty
- Hip Muscle Strains
- Hyperextension Injury of the Elbow
- Iliotibial Band Syndrome
- Interventional Pain Management
- Interventional Spine
- Intraarticular Calcaneal Fracture
- Knee & Leg
- Kyphosis
- Labral Tears Of The Hip (Acetabular Labrum Tears)
- Lateral Collateral Ligament (LCL) Injuries
- Lisfranc Injuries
- LITTLE LEAGUER'S ELBOW (MEDIAL APOPHYSITIS)
- MACI
- MAKO Knee Replacement Surgery
- MAKO Total Hip Replacement
- Mallet, Hammer & Claw Toes
- Medial Collateral Ligament Injuries
- Meniscus Tears
- Metatarsalgia
- Minimally Invasive Spine Surgery
- Morton’s Neuroma
- Muscle Spasms
- NAVIO Surgical System
- Nerve Pain
- Neuromas (Foot)
- Olecranon Stress Fractures
- Orthopaedic Total Wellness
- Orthopedic Trauma
- Osteoarthritis of the Hip
- Osteoporosis
- Outpatient Spine Surgery
- Partial Knee Replacement
- Patellar Fracture
- Pelvic Ring Fractures
- Peripheral Nerve Surgery (Hand) Revision
- Pinched Nerve
- Plantar Fasciitis
- Podiatrist or Orthopaedic Physician?
- Primary Care Orthopedics Sports Medicine
- PROstep™ Minimally Invasive Surgery for Bunions
- Quadriceps Tendon Tear
- Revascularization of the Hand
- Reverse Total Shoulder Replacement
- Revision Knee Surgery
- Rheumatoid Arthritis (RA) of the Shoulder
- Rheumatoid Arthritis Of The Hand
- Robotics
- ROSA® Knee Robotic Surgical Assistant
- Sciatica
- Scoliosis
- Senior Strong
- Shin Splints
- Shoulder
- Shoulder Arthritis
- Shoulder Arthroscopy
- Shoulder Replacement
- Shoulder Socket Fracture (Glenoid Fracture)
- SLAP Tears & Repairs
- Spinal Fusion
- Spine
- Spondylolisthesis and Spondylolysis
- Sports Hernias (Athletic Pubalgia)
- Sports Medicine
- Sprained Ankle
- Sudden (Acute) Finger, Hand & Wrist Injuries
- Targeted Muscle Reinnervation (TMR)
- Tendon Transfers of The Hand
- Tennis Elbow
- Thigh Fractures
- Thigh Muscle Strains
- Total Ankle Replacement
- Total Hip Arthroplasty
- Total Hip Replacement - Anterior Approach
- Total Knee Replacement
- Triceps Tendonitis
- Trigger Finger
- UCL (Ulnar Collateral Ligament) Injuries
- Ulnar Neuritis
- Valgus Extension Overload
- Verilast
- Vertebroplasty
- WALANT (Wide Awake Local Anesthesia No Tourniquet)
- Whiplash and Whiplash Associated Disorder (WAD)
- Wrist Arthroscopy
- Wrist Fractures
- Wrist Sprains
- Wrist Tendonitis