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(SACRAMENTO, Calif.) -- UC Davis Medical Center is among a small number of hospitals in the nation implanting artificial cervical discs in patients with degenerative disc disease.
"We are seeing an evolution in spine surgery," said Kee Kim, assistant professor and chief of spinal neurosurgery. "The current standard of treatment is rather crude in that it changes the mechanics of the spine and may cause stiffness in the neck. The artificial implant is designed to preserve motion, and could potentially eliminate complications with fusion."
This is the first time artificial cervical discs have been implanted in patients in Sacramento. Patients with degenerative disc disease are participating in a randomized clinical trial comparing the current standard of treatment -- replacement bone and spinal fusion -- with an artificial cervical disc, an all-metal prosthesis intended to maintain motion. The trial is being conducted at 35 clinical sites around the country. Nationwide, 550 patients will be enrolled in the study over a period of two years.
During the past three weeks, three patients received artificial implants at UC Davis Medical Center, including Sacramento resident Kathy Cregan.
"The patients who received the artificial cervical discs had very disabling neck pain that caused headaches and tingling and numbness in the arms. Sometimes pain or tingling even extended into hands. All of the patients had tried non-surgical treatment without success," said Kim, principal investigator of the study.
Spinal discs are gel-like cushions that act as shock absorbers between the vertebrae in the spine. Herniation, which results from disc degeneration, injury or heavy lifting, can cause a portion of the cervical disc to be pushed out of place and press on adjacent nerve endings connected to the arm.
Patients who meet the criteria for the study are being randomized to either spinal fusion or artificial cervical spine surgery.
"We follow the two groups to assess the outcome, evaluating pain and level of function to determine if the new procedure is equal to the standard of treatment or better," said Kim.
The new procedure is similar to spinal fusion -- an incision is made in the neck, tissue is dissected lateral to the airway, and damaged discs are removed. Instead of inserting replacement bone and screws, the surgeon implants a metal prosthesis, consisting of two metallic components designed to pivot. The implant is secured to the vertebrae with screws.
"In terms of pain relief, it can be quite dramatic. Some patients even notice it in the recovery room, but usually it takes a little bit of time because they are using medication. When we see them for follow-up, they report significant improvement."
Many types of artificial cervical discs have been developed and studied over the past 40 years, but the FDA has approved none. Currently, a few clinical trials are under way using devices from various manufacturers.
Kim said patients with degenerative discs are very interested in artificial cervical discs and are pushing the development of this surgery.
"I do believe this will be a very important part of the future of spinal surgery, and we are just at the preliminary stage here in the United States in terms of trying to figure out if this is better than the current standard of treatment," he said.
Spine patients interested in participating in the study should be over age 18, not pregnant, diagnosed with cervical degenerative disc disease, unresponsive to non-surgical intervention and show signs of progressive nerve root or spinal cord compression.
For more information about the study, contact the recruitment coordinator, Martha Robinson, at 916-734-3660.