The USF Department of Neurosurgery and Brain Repair was awarded a patent for a spine disc prosthetic device with fusion capability, helping patients with degenerative discs or scoliosis to have a shorter and less painful recovery.

The significance of the device – a pouch filled with beads that is implanted into the spine and functions as a vertebral disc – is that it can be implanted in a less invasive manner and that it allows the spine to more easily fuse to the pouch than it will to other devices currently used.

Co-inventors for the device and the method for using it are: Thomas Freeman, MD, professor of Neurosurgery and medical director of the USF Center for Aging and Brain Repair in the Department of Neurosurgery and Brain Repair, and Wesley Johnson, PhD, a biomechanics engineer who recently retired from the USF Department of Neurosurgery and Brain Repair.

Thomas Freeman, MD,  (left)  and Wesley Johnson, PhD

“The device is unique in the industry because it accommodates conversion from a motion preservation device to a spine fusion device,” Dr. Johnson said.

“It was a device inspired by the late Dr. David Cahill.”

Dr. Cahill, who passed away in 2003, was professor, chairman and founder of the Department of Neurological Surgery at USF. He was an international renowned neurosurgeon and noted for his teaching and his innovation in spinal instrumentation.

“I was hired by Dr. Cahill in the spring of 2003,” Dr. Johnson said. “During my interviews he and I shared our common frustration with the current state of the art.  I reported for my first day and he died the next day in the airplane crash.  I felt a certain sense of satisfaction when the patent was issued.”

Degenerative discs can cause significant pain.

Typically, the options for patients would include removing the problem disc and replacing it with a stiff strut or cage, which could mean additional plates, rods, and screws to stabilize the disc until it heals and the bone fuses across the disc space. But in as many as 20 percent of these procedures, fusion does not occur. In addition, screws and rods can shift, causing serious neurological complications. When fusion does occur, there is a greater likelihood that an adjacent disc then fails.

Motion preservation devices allow more range of motion of the spine than a fusion, Dr. Freeman added.  However, if a standard motion preservation device has to be converted to a fusion for any reason at a later date, this requires a major operation.  The benefit of this new patented device is that it allows for the conversion from a motion preservation device to a fusion device with a simple, quick, minimally invasive procedure that can be performed as an outpatient.

Click here for more information on the patent and device.

Story by Sarah A. Worth, USF Health Office of Communications