Bioactive materials in orthopaedic surgery: overview and regulatory considerations.

Although bone graft continues to be the standard against which other skeletal substitutes are measured, orthopaedic surgeons soon will have various new tools available for skeletal reconstruction. With these tools, the distinctions between inert materials, resorbables, bioactive materials, transplantable tissues, engineered tissues, drugs, and composites become indistinct. Although almost any implanted material evokes some type of host reaction, in the context of reconstructive orthopaedic surgery, bioactive materials can be considered osteogenic, osteoconductive, osteoinductive, or a combination thereof. In the United States, the regulatory control of a new skeletal substitute material is complex, and is based in part on whether the material is considered primarily a biologic, a drug, or a medical device. Different agencies within the Food and Drug Administration have responsibility for regulatory control of different types of products. Although some new materials can be approved by a Premarket Notification (510(K)), others require a Premarket Approval Application. Regulations are being developed that affect the extent of regulatory influence over minimally manipulated tissues for transplantation.