Researchers Paid by Medical Company Missed Flaws in Its Spine Implant, Study Finds

June 29, 2011

Researchers paid by the maker of a spinal bone-graft implant conducted a total of 13 medical trials involving hundreds of patients without reporting any evidence of problems now known to exist with the product, a study has concluded.

The researchers, about half of whom had university affiliations, were paid a total of at least $60-million to $70-million by the company, Medtronic Inc., with not all of it disclosed by the researchers in their published findings, said an author of the study, Alexander J. Ghanayem, chief of spine surgery at Loyola University Medical Center.

Results of the study by Dr. Ghanayem and his colleagues were published in the June issue of The Spine Journal with accompanying commentary articles citing it as yet more evidence of the harm caused by unacknowledged financial conflicts of interest in medicine.

Dr. Ghanayem said he didn't have evidence to demonstrate any fraud, and instead criticized the researchers' lack of full financial disclosure. "If the people that publish those studies believe that's what they saw, fine," he said in an interview. "But at least disclose your relationship, and let us make the final decision as to whether or not we want to embrace that scientific finding. That's all."

Dr. Ghanayem prepared the study along with Eugene J. Carragee, a professor of orthopedic surgery at Stanford University; Bradley K. Weiner, a professor and vice chairman of orthopedics at Weill Cornell Medical College; Christopher M. Bono, an assistant professor at Harvard Medical School and chief of spine service at Brigham and Women's Hospital; and David J. Rothman, president of the Institute on Medicine as a Profession, a watchdog group based at Columbia University.

Their study concerned Medtronic's "Infuse" bone graft. The product is designed to let doctors perform certain types of spinal-fusion surgeries without harvesting bone from the hip. But an estimated 85 percent of the product's sales involve uses other than the specific type of surgery approved by the U.S. Food and Drug Administration for Infuse, often at the recommendation of doctors influenced by published medical trials. Medtronic has reported more than $700-million annual sales of Infuse.

The 13 medical trials conducted by researchers who received Medtronic payments involved 780 patients, without any physicians reporting a single adverse event attributed to Infuse, the study by Dr. Ghanayem and colleagues found. Other medical studies, however, have found serious complications, including inflammatory reactions, cancer, infection, and implant dislodgement, Dr. Ghanayem and his colleagues reported.

The 13 trials were conducted by a total of 20 to 25 researchers, among them Thomas A. Zdeblick, chairman of orthopedics at the University of Wisconsin at Madison; Scott D. Boden, a professor of orthopedic surgery at Emory University; and Harvinder S. Sandhu, an associate professor of orthopedic surgery at Weill.

In some situations, the 20 to 25 researchers—including Drs. Zdeblick, Boden and Sandhu—did disclose at least some type of financial relationship with Medtronic. Some, however, disclosed nothing of the financial relationship, and others did so in a manner that did not appear clear or complete, the authors said.

The newly appointed chief executive of Medtronic, Omar S. Ishrak, issued a written statement saying The Spine Journal reports "raise questions" about the conclusions in the published studies, and promising to investigate the matter internally.

Dr. Ghanayem said his findings are causing him worry about the overall state of medical research. "In the spine world," he said, "I know exactly what's going on because I'm in it. What I worry about is, What's happening with the drug I'm using for my cholesterol, or the drug that my dad takes for hypertension? I have no idea what's going on. I might as well be the average guy on the street when it comes to those issues. This bone-graft issue is not the issue. It's a bigger issue involving all of medical devices and medical drugs."