Medtronic’s experimental spine implant was recommended for approval by the FDA advisory panel with a 6-5 vote that benefits of the Amplify device outweigh risks. Three panelists abstained.

However, the FDA's Orthopaedic and Rehabilitation Devices Advisory Panel voiced concern about cancer cases seen in some patients treated with Amplify.

Medtronic Inc. say that Amplify is superior at fusing vertebral bone compared with the current standard fusion surgery, which uses a piece of a patient’s hip bone implanted in the spine.

Amplify contains a genetically engineered form of a protein to help fuse vertebrae by promoting bone growth in patients with degenerative disc disease. Combined with a compression resistant matrix and a metallic posterior spinal instrument, the protein used in Amplify is called recombinant human bone morphogenetic protein-2, or rhBMP-2.
Similar bone-growth product made by Medtronic called Infuse, approved in 2002, is currently used for around 300,000 spine fusion surgeries performed in the United States.

Medtronic studied 463 patients randomly chosen to receive the new device Amplify or the standard fusion procedure. After two years, 60.5 percent of Amplify procedures were judged a success compared with 55.5 percent in the control group.

However, FDA reviewers saw that cancer cases appeared more in patients treated with Amplify.

Cancer rates five years after the procedure were higher for Amplify with 5 percent compared to 1.8 percent in the standard fusion group.

Panel members were split on whether the protein in the device is linked to cancers.

Medtronic said the differences were not statistically significant and they could have been due to chance without any biological reason.

Panel members voted 9-4, with one abstention, that Medtronic provided "reasonable assurance" that Amplify was safe but later cited that cancer data are too inconclusive to rule out a cancer link.

Some said their concerns were eased because the reported cancers were several different types. If the device was to blame, it is likely the cancers would be similar, they said.

"Seeing a smattering of all these different cancers ... it doesn't raise a red flag to me," said panelist Mary Kemeny, an oncologist at Queens Cancer Center in New York.

Several panel members urged more study of cancer rates after the device reaches the market.

In its decision, it is uncertain whether the FDA will follow the panel’s recommendation.