US regulators have warned that Amplify, Medtronic's experimental spinal fusion device, does not work as well after five years as it did after two.
After two years, 61% of Amplify surgeries were successful compared with 56% for standard care, the US Food and Drug Administration (FDA) said. After five years, 44% of Amplify surgeries were successful compared with 35% for standard care.
After two years, 3.8% of Amplify patients had cancer, compared with 0.9% who had standard surgery. This increased to 5% after five years, compared with 1.8% for traditional grafts, according to the FDA report.
The company's bone growth protein, known as rhBMP-2 is combined with a ceramic device in Amplify and implanted in the spine for posterior spinal fusion through a patient's lower back.
In the two-year Medtronic's study of 463 patients, those treated with the device had shorter surgical times, less blood loss and needed fewer repeat operations compared with those who had the standard procedure.
The agency will meet its advisers to evaluate Amplify. It will look at how the overall surgical success rates for the two study groups were determined, and evaluate the greater number of serious back and leg pain side effects reported by patients in the Amplify group, according to Bloomberg.
