Clinicians should avoid routine off-label use of certain bone graft substitutes in patients younger than 18 years of age with bone disorders because of the risk for serious injury, the US Food and Drug Administration (FDA) announced today.

The bone graft substitutes in question contain recombinant proteins or synthetic peptides that mimic natural bone-growth substances. Combined with a carrier or scaffold, these ingredients are implanted in someone to replace or heal an existing bone or to promote new bone growth.

The FDA has approved such bone graft substitutes for orthopedic and dental use in patients 18 years of age and older whose bones have stopped growing. However, the bone graft substitutes have never been approved for a younger population whose skeletons are still developing, the FDA said in a news release, because the extra stimulation for bone growth can lead to serious injuries. The agency noted that it has not reviewed the safety and effectiveness of these bone graft substitutes in patients younger than 18 years.

Despite the FDA's previous regulatory decisions, clinicians use bone graft substitutes incorporating recombinant proteins and synthetic peptides on an off-label basis for patients younger than 18 years. The agency said it has received reports of excess bone growth, fluid accumulation, inhibited bone healing, swelling, and other adverse events in this juvenile population.

These problems occur in older patients, but pose more of a threat to younger ones because of their ongoing bone growth and overall smaller size. For example, the excess bone growth and fluid accumulation that can result from using one of these products in the spine can more easily lead to spinal cord damage in a younger patient than an older one. That is because there is less space between the spinal cord and the surrounding bones in younger patients. Similar adverse events can put harmful pressure on other adjacent tissues and organs.

Before resorting to bone graft substitutes containing recombinant proteins or synthetic peptides in a juvenile patient, the FDA said, clinicians should first consider three other options:

· autograft bone, which is harvested from another part of the patient's body;

· allograft bone, which is transplanted from another person's body; and

· FDA-approved bone graft substitutes that do not contain recombinant proteins or synthetic peptides.

More information on today's announcement is available on the FDA website.

Source: Medscape