Targeted Muscle Reinnervation for the Treatment of Postamputation Pain

To begin, evaluate the flexibility of the soft tissue surrounding the nerve of the neuroma. Plan skin incisions based on the findings from the physical assessment and EMG evaluation. Perform the skin incision with the scalpel at the location of the painful neuroma.

Identify the donor nerve through blunt dissection, then isolate the donor nerve along with the neuroma using loop magnification and microsurgical instruments. Mobilize the donor nerve as needed to reach the recipient site. Transect the neuroma using a commercial nerve cutting set and repeat for each nerve with an identified painful neuroma in the current exposed area.

Next, perform a blunt dissection to identify all motor nerve branches to the target muscle. Set the handheld nerve stimulator between 0.5 to one milliamperes, and put it in contact with each of the nerve branches to stimulate them. Identify the nerve causing the largest muscle contraction to be the recipient nerve.

Denervate the target muscle completely when possible. Once active contraction is confirmed, use straight micro scissors to transect the nerve without tension near its entry point, aiming for less than one centimeter. Transpose the proximal stump of the transected donor nerve proximally away from the coaptation site without specific management.

Next, perform nerve to nerve coaptation by suturing the donor nerve to the recipient residual or target motor nerve with an 8-0 non-resorbable monofilament suture. Place the stitch in the center of the donor nerve. Reinforce the suture with additional stitches to secure the donor nerve epineurium to the surrounding fascia and epimysium of the recipient nerve.

Ensure the coaptation is tension-free and without excess redundancy.