Bone graft substitutes containing recombinant proteins or synthetic peptides In a safety alert issued Jan. 21, the U.S. Food and Drug Administration (FDA) warned that bone graft substitutes containing recombinant proteins or synthetic peptides, such as Medtronic Infuse, should not be used in patients younger than 18. The agency said it was aware of reports of serious injuries, such as excess bone growth, fluid accumulation, inhibited bone healing and swelling, linked to using the bone graft substitutes in patients under the age of 18.
Bone graft substitutes containing recombinant proteins or synthetic peptides such as Medtronic Infuse are used to promote bone growth in patients with a bone defect. This type of bone graft is meant as an alternative to autograph bone, where bone is harvested from another part of the patient’s body, and allograft where bone is transplanted from another individual.
The FDA never approved Medtronic Infuse for patients under the age of 18. The product is already controversial in adults, with similar adverse events reported. According to the safety alert, however, these issues are even more pressing in patients under age 18 because they tend to be smaller and their bones are not done growing. “Any product that affects bone growth could have the potential to negatively impact skeletal development by altering normal bone formation and growth, especially if implanted near open growth plates.” the alert states.
Medtronic Infuse and other similar products are classified as high-risk (Class III) medical devices. For these products, manufacturers are required to submit clinical data to show that they are safe and effective. No such protocol was implemented for patients under age 18.
The agency stated in its notification that it “recommends against routine use of these products in patients under age 18 because their safety and effectiveness has not been reviewed or approved for use in this population.” The FDA also recommends considering autograft or allograft bone as alternatives in patients younger than 18. Patients under the age of 18 who have undergone a procedure with this type of product should be closely monitored for complications, which may include problems with skeletal development, excess growth of other tissues and tissue swelling or fluid accumulation that could put pressure on nearby organs or tissues.
Medtronic Infuse has become a controversial product in general. In 2011, a group spine experts made a bold and unusual move by publicly rebuking Medtronic-funded research on Infuse. In an entire issue of the Spine Journal they criticized Medtronic-paid researchers for failing to mention a number of side effects, including male sterility. The publication prompted several investigations; later on, a Senate report found that Medtronic employees helped write and edit studies promoting Infuse. Medtronic has also been sued over allegations of off-label promotion with Infuse.