Doctors Test Devices to Treat Failing Discs in Lower Spine

September 14, 2010

Two surgeons at Mercy Regional Medical Center are participants in nationwide clinical trials of devices designed to ease lower-back and leg pain resulting from a compromised lower spine.

Dr. Jim Youssef and Dr. Douglas Orndorff of Durango Orthopedic Associates/Spine Colorado described their work recently in an interview, illustrating their explanation with artificial vertebrae of the lumbar region, the lowest five joints in the spine.

As a primer, Youssef and Orndorff explained why millions of adults suffer debilitating or incapacitating lower-back and leg pain:

The spine is a delicate network of interconnected vertebrae. A disc of tough, fibrous material between vertebrae acts as a shock absorber; and wingnut-like protrusions called facet joints on either side of the rear of the spine hold vertebrae in place and give the torso flexibility.

As people age, discs lose their resiliency and can rupture, reducing the space between vertebrae and squeezing nerves. The result can be lower-back or leg pain, tingling or numbness.

Traditional nonsurgical treatment of spinal stenosis includes physical therapy, injections and chiropractic care. If surgery is needed, adjoining discs can be fused, immobilizing the spine and reducing the range of movement.

Research has led to the development of metal devices – inserted through minimally-intrusive incisions – that restore normal spine movement. One device that Youssef and Orndorff are testing replaces a degenerative disc, and the other restores the normal disc space between vertebrae, relieving pressure on nerves and spinal cord and restoring motion:

The XL TDR is a metallic replica of a disc that is inserted between vertebrae when a disc has degenerated to the point it must be replaced. The surgeon removes the degenerative disc and installs the XL TDR, which separates vertebrae in order to maintain their natural positions and normal flexibility.

Unlike similar devices that require opening the abdomen, the surgeon gets to the spine through the patient’s side. The minimally invasive procedure allows the surgeon to avoid vital organs and promotes quicker recovery.

The other device, the Superion Interspinous Spacer, is implanted in folded position, through a tube, between bones called spinous processes and is then cranked open like a vehicle jack to separate vertebrae. The spacer, inserted in the back through a hole the size of a dime, is used when the surgeon wants to relieve pressure on pinched nerves.

The Superion is being tested to rate its effectiveness compared with a similar device already on the market.

Clinical trials, which test the effectiveness of devices, procedures and drugs, are conducted in the United States only after they’ve proven safe and reliable.

Teena Augustino, a clinical-trial consultant to Vertiflex, the manufacturer of the Superion spacer, said in a telephone interview that it’s a feather in the cap of a medical office and its physicians to be selected for clinical trials.

“It’s prestigious because the Federal Drug Administration limits the number of trial sites, and the manufacturer, with a large investment, is very selective,” Augustino said. “We scour the country for sites.”

Medical facilities where successful trials have been conducted are viewed very favorably, Augustino said. Sites with proven infrastructure and staff and an adequate number of potential patients are required, she said.

Patrick O’Connor, marketing director/new technology at Vertiflex, said 28 facilities across the country, including three in Colorado, have been chosen to test the Superion spacer.