(Fortune Magazine) -- On a recent July morning at Plano Presbyterian Center for Diagnostics and Surgery, Ron Cady, a 53-year-old truck driver, waits to be wheeled into the operating room to receive two Charité artificial spinal disks from Texas Back Institute surgeon Scott Blumenthal.

Cady's wife, DiAnna, sits nearby, nervously tapping her foot. Half-an-hour later, to the soothing melodies of Simon and Garfunkel, Blumenthal - who performed the first Charité surgery in the U.S. - removes Cady's diseased disks with a scary forceps-like tool called a rongeur, spreads Cady's spinal vertebrae apart with a metal retractor, and then pounds on Cady's vertebrae with a metal mallet to make the disks fit.

About an hour later, Blumenthal is done. "It was smooth - like butter," he says, as another doctor stitches Cady up. Made by DePuy Spine, a unit of Johnson & Johnson, the Charité devices Cady received consist of a hard plastic disk that floats between two metal plates.

Available in Europe since 1988, it wasn't approved by the FDA until 2004. In Charité's FDA trial, J&J needed to prove only that it was no worse than getting a spinal fusion, a common procedure where spinal vertebrae are fused. Because Charité surgery is new to these shores, there is a paucity of long-term patient data on its effectiveness or durability. U.S. insurers are not persuaded by European studies.

For those reasons, and others, only two national insurers, Aetna and Kaiser, cover the surgery, which at TBI costs $18,000 per disk. (Cady was covered by his workers' comp insurance.) TBI was closely involved in the Charité FDA trials, and it is also researching a competing disk called ProDisc, made by Switzerland-based Synthes, which gained FDA approval in August. Banc of America Securities analyst Steven Lichtman projects that this market could reach $1 billion by 2010. "This is the future of spine," says Blumenthal.

Reporter associate Joan L. Levinstein contributed to this article.