LEIPZIG – A review of the first 40 patients who underwent
targeted muscle reinnervation (TMR) shows a 96% success rate,
according to Laura Miller, PhD, CP, of the Rehabilitation Institute of Chicago
and O&P Business News Practitioner Advisory Council member.
She presented her research group’s findings at the 13th ISPO World
Congress.
A total of 98 nerve transfers have been performed.
“In terms of surgical outcomes, of the 98 transfers there are four
that are documented as failures. Two of those were in an individual with a
transhumeral amputation. At the time of surgery, they noted he had radial nerve
atrophy and it was likely an undiagnosed brachial plexopathy. Because of that,
neither medial nor distal radial nerve transfer was successful,” Miller
explained in her presentation.
Another failure was recorded in the first patient ever to receive TMR.
The additional patient with a recorded failure has a small but unusable EMG
signal.
“Approximately 94 of the 98 known transfers that we’ve been
able to document at this time have been successful in producing reportable
EMG,” Miller said, “That is a 96% success rate.”
Miller said that number should not be too surprising due to
hyper-reinneravation.
“Hyper-reinneravation is when you have a large nerve and you
connect it to a small muscle nerve,” she said. “As the nerve you are
connecting to the muscle gets bigger, relative to the size of the muscle
itself, your success rate improves.”
Miller’s research team also recorded an increase or recurrence of
phantom limb pain as a result of re-amputating nerves, though generally not as
bad as initial levels and usually returning to baseline in 3 to 6 weeks.
— by Jennifer Hoydicz
