The use of biological augments in fracture healing: where is the evidence?

Fracture non-union results in serious morbidity for patients and a financial burden on healthcare services. Fracture healing is a complex process that involves many chemical signalling molecules and cells. This complexity means there are many stages at which the healing pathway can theoretically be influenced by biologic adjuvants. Biologic adjuvants can be either osteoconductive, osteoinductive or osteogenic. Many laboratory studies have shown success in manipulating the signalling pathways involved in fracture healing. The majority of biologics serve to increase the presence of certain cytokines to stimulate bone forming cells; some agents involve effecting the delivery of early progenitor cells. There have been clinical trials involving multiple biologics, usually in the treatment of tibial non-unions. The clinical trials have shown very limited evidence to support the use of adjuvants in clinical practice. There is a consistent problem translating encouraging laboratory results into similar clinical results with the majority of agents, therefore there remains a lack of clinical evidence to support their use in everyday trauma practice. [ABSTRACT FROM AUTHOR]