Peripheral nerve transfer restores hand function

From the 2012 Department of Surgery Annual Report

C6-C7 Spinal InjuryAfter surgery to restore hand function, intensive physical therapy is required to retrain the brain to communicate with new nerve connections.WASHINGTON UNIVERSITY plastic and reconstructive surgeons have restored some hand function in a quadriplegic patient with a spinal cord injury at the C7 vertebra, the lowest bone in the neck. Instead of operating on the spine itself, the surgeons rerouted working nerves in the upper arms. These nerves still “talk” to the brain because they attach to the spine above the injury.

Following the surgery, performed at Barnes-Jewish Hospital, and one year of intensive physical therapy, the patient regained some hand function,specifically the ability to bend the thumb and index finger. He can now feed himself bite-size pieces of food and write with assistance.

The case study, published online in the Journal of Neurosurgery, is, to the authors’ knowledge, the first reported case of using nerve transfers to restore the ability to flex the thumb and index finger after a spinal cord injury.

“This procedure is unusual for treating quadriplegia because we do not attempt to go back into the spinal cord where the injury is,” says plastic surgeon Ida Fox, MD. “Instead, we go out to where we know things work — in this case the elbow — so that we can borrow nerves there and reroute them to give hand function. If we can restore the ability to pinch between the thumb and index finger, it can return some very basic independence.”

The surgery was developed and performed by the study’s senior author Susan Mackinnon, MD, the Sydney M. Shoenberg Jr. and Robert H. Shoenberg Professor and chief of the Division of Plastic and Reconstructive Surgery. Specializing in injuries to peripheral nerves, she has pioneered similar surgeries to return function to injured arms and legs.

Mackinnon operated in the upper arms; she took a non-working nerve that controls the ability to pinch and plugged it into a working nerve that drives one of two muscles that flex the elbow. After the surgery, the bicep still flexes the elbow, but the nerve to the brachialis muscle, which also flexes the elbow, now bends the thumb and index finger.

Mackinnon does not anticipate a limited window of time for performing the surgery. Spinal cord injury, unlike peripheral nerve injury, allows for repair in the right circumstances even years after injury. But it will not benefit patients with higher injuries, in vertebrae C1 through C5, and it cannot restore leg or bowel/bladder function.