Principles of Nonunion Management: State of the Art.

A substantial proportion of fractures can present with nonunion, and the management of nonunion continues to present a challenge for orthopaedic surgeons. A variety of biological, mechanical, patient, and injury factors can contribute to the occurrence of nonunion, and often the cause of nonunion may be multifactorial. Successful management often requires assessment and treatment of more than one of these factors. This article reviews common factors that may contribute to nonunion including infection, impaired biology, and metabolic disorders. In addition, new and evolving strategies for diagnosing the cause and effectively treating nonunion including the diagnosis of infection, metabolic workup, bone grafting, cell-based therapies, and biological adjuvants are reviewed and discussed.