Add lower back pain to death and taxes on the list of inevitable afflictions for modern American life.
Four in five adult Americans will suffer significant lower back pain at some point, according to the American Academy of Orthopaedic Surgeons. And back conditions resulted in about 5.6 million visits to doctor's offices and 528,000 hospitalizations in 1994, the academy says.
Although most problems respond to a combination of medication, exercise and behavior modification, more than 100,000 people will resort to surgery each year in a desperate bid for pain relief, according to industry estimates.
Until recently, such procedures, known as surgical spinal fixation, most commonly used bone screws, plates and rods-some of which had limited marketing approval and all of which had room for improvement.
But in the past year, new implants known as spine cages received the green light from the Food and Drug Administration. The cages usually are implanted only after the cartilage disks between vertebrae have degenerated seriously. They provide a frame for bone growth to fuse the spine, steadying unstable backs and relieving pressure on nerves.
A supply of cages for a typical operation costs $2,000 to $5,000, depending on how many are needed.
Experienced surgeons say these hollow titanium screws are easier to use, resulting in shorter operations and hospital stays. One study of 75 back operations showed patients had an average hospital stay of 3.5 days after undergoing spine cage implants, compared with 5.5 days after traditional spinal fixation. The cages also promise a quicker recovery.
"They're a huge improvement over what we've had in the past," says Kevin Gill, M.D., an associate clinical professor of orthopedic surgery at University of Texas Southwestern Medicine School in Dallas.
The cages are "a revolution and a very profitable revolution," says Robin Young, an analyst at Little Rock, Ark.-based Stephens, a brokerage firm.
For now, Spine-Tech of Minneapolis and U.S. Surgical Corp. of Norwalk, Conn., have the spine cage market to themselves. In its infancy, the U.S. market could approach $500 million within a few years, Young estimates.
Sales are skyrocketing. In its second quarter ended June 30, U.S. Surgical saw sales in its spinal products division top $13 million from less than $2 million in the year-ago period. Spine-Tech reported sales of $12 million in the second quarter ended June 30, eight times larger than 1996 second-quarter sales.
And late last month Spine-Tech won FDA approval to market its cages for laparoscopic implantation. The minimally invasive approach should accelerate adoption of its cages by reducing hospital stays and recovery times even further, the company says.
Regardless of the surgical approach, pairs of these cages-which are threaded titanium metal screws-are inserted between a patient's vertebrae. Packed with bone usually harvested from the patient's femur, the cages promote fusion of the spine and relieve pain in more than 80% of patients, according to various studies.
Yet surgeons say they should be used sparingly.
"The trick on these cases is being a careful chooser," says Robert Hacker, M.D., a neurosurgeon at Sacred Heart Hospital in Eugene, Ore. "Not everyone with back pain needs a cage put in their back. You have to use this with the utmost discretion."
The relatively high cost of the inch-long screws isn't helping speed their adoption. "In my opinion, these cages are way overpriced," Hacker says.
He says that careful diagnoses, including X-ray testing that uses dye, are vital for appropriate selection of patients for the cages.
Vert Mooney, M.D., an orthopedic surgeon at the University of California-San Diego School of Medicine, also believes manufacturers are charging too much for the cages, even given development and operational costs. He says he is eager for added competition in the market.
The spine cage is "a better way of doing fusions," Mooney says, although he doesn't believe, like some boosters, that the technology will make fusion surgery more common.
Meanwhile, payers haven't jumped on the bandwagon. "On the reimbursement side there are open questions," Stephens' Young says. "HMOs are looking at the cost of all these procedures very carefully."
Hacker believes enlightened insurers will come around. In his study, patients suffered serious pain for an average of more than 22 months. Surgery resulted in good or excellent outcomes for more than two-thirds of the patients, whether vertebrae were fused conventionally or with cages.
"You make those people feel better," Hacker says, "and they think you're Oral Roberts."