The Evidence Basis and Regulatory Framework for Biologic Augmentation of Foot and Ankle Surgeries.

Biologic augmentation, using substances like bone marrow aspirate concentrate (BMAC) and platelet-rich plasma (PRP), shows promise for improving outcomes in foot and ankle surgery, particularly in high-risk patients. Historically, autologous bone graft is the benchmark due to its trifecta of osteogenic, osteoinductive, and osteoconductive properties, despite its associated donor site morbidity. Current evidence supporting orthobiologics remains fragmented and inconclusive, with a lack of high-level randomized controlled trials (RCTs). BMAC shows fusion rates comparable to autograft in some foot and ankle applications, but PRP evidence is often conflicting due to a lack of preparation standardization. The regulatory environment is complex. The Food and Drug Administration (FDA) oversees human cells and tissues (HCT/Ps) through a tiered system: high-risk §351 products (eg, cultured stem cells) require rigorous premarket approval, whereas §361 products (eg, allograft bone) have minimal oversight. BMAC and PRP often bypass this through the Same Surgical Procedure Exemption or are regulated through their processing devices, meaning the biologics themselves are not FDA-approved therapeutics. This regulatory gap and direct-to-consumer marketing necessitate meticulous informed consent, transparently discussing the lack of specific FDA approval, limited evidence, and high out-of-pocket costs. Future success depends on standardized, prospective RCTs and a collaborative "middle-ground pathway" for regulatory approval.