The use of implanted hardware in spinal-fusion surgeries for lower-back pain does not improve the results and carries a higher risk of complications, researchers are reporting today.
The study published in the journal Spine is the latest to cast doubt on the increasingly common use of spinal screws and cages during surgeries in which vertebrae are fused to relieve pain.
The findings “should add to our level of skepticism about benefits of the hardware and the procedure itself,” said Dr. Richard Deyo, a professor of medicine at the University of Washington who was not involved in the study.
Deyo has researched back- pain treatments, and his lab is partly supported with funds from a device maker.
More than 150,000 Americans undergo spinal fusions for lower-back pain each year.
The process involves using bone grafts with or without surgical implants to fuse two or more vertebrae.
The surgery is performed when the vertebrae or the cushioning disks between vertebrae become weakened or damaged by injury or disease.
The procedure became popular with the introduction in 1996 of spinal cages, devices that hold bone grafts in place while keeping pressure off the disc.
Recent European studies have raised questions about the benefits of spinal fusion in general. A head-to-head study in Britain last year found spinal surgery offered no clear advantages over intensive rehabilitation therapy for patients with chronic lower-back pain. This year, a Norwegian study found spinal fusion was no better than physical therapy in patients who had undergone previous back surgery.
Both studies involved the use of implants.
In the latest report, researchers from the University of Washington examined records from that state’s workers’ compensation system on 1,950 workers who had spinal-fusion surgery for chronic lower-back pain between 1994 and 2001.
Patients fell into four groups. Some received only cages; others received other devices, such as rods and screws; another group received cages plus other devices; the final group did not get implants.
Two years after surgery, about 60 percent of patients in each group remained disabled, researchers said. Patients with implants, however, had twice the risk of postsurgical complications.
Dr. Gary Franklin, medical director of the Washington Department of Labor and Industry, which funded the study, said it was clear that the devices did not benefit patients.
But he added that the high rate of long-term disability in all of the patients suggested that spinal fusion, regardless of whether hardware was used, was of little benefit.
