Review Question - QID 211518

Of the above materials, only bone morphogenic protein (BMP) exhibits solely osteoinductive properties.

BMPs, along with other growth factors such as PDGF, IGF, FGF, TGF-beta, and interleukins influence bone formation through intramembranous ossification by osteoblasts, while chondroblasts begin a process of cartilage formation at the fracture site (soft callus) that is
eventually replaced by bone through enchondral ossification. Furthermore, BMPs are capable of stimulating angiogenic factor production in local cells (such as osteoblasts) and this is critical for its osteoinductive properites especially in the case of an atrophic nonunion.

Sen et al. investigated reviewed the use of iliac crest bone graft still as the gold standard for treating nonunions. They reported that nonunion treatment has traditionally included iliac crest autograft to augment biology. They however noted the associated morbidity with harvesting of the graft, and highlighted alternatives such as bone marrow aspirate, platelet-rich plasma, and allograft.

Mahendra et al. reviewed available biological treatments for complex nonunions. They reported that most cases of aseptic nonunions require some degree of biological augmentation, of which autologous iliac crest bone graft remains the gold standard. They highlighted that various scaffolds,
demineralized bone matrices (DBM) and BMPs are commercially available but
need further refining and that stem cell and gene therapy are evolving and likely to impact significantly in the next few decades.

Incorrect Answers:
Answer 1: Cancellous allograft is predominantly osteoconductive.
Answer 3: Distal tibial autograft exhibits both osteoinductive AND osteoconductive properties.
Answer 3: Calcium hydroxyapatite is not osteoinductive.
Answer 5: PMMA has no osteoinductive properties.