What bone substitutes for what bone loss

Bone loss is a common situation in orthopedic and trauma surgery which may be due to many different etiologies. Many options are available for surgeons to fill the bone loss. Bone substitutes are now commonly used, which can belong to different families, in most cases of synthetic origin. The choice for filling bone loss is depending upon many factors: etiology, volume to be filled, age of the patient...Advantages and disadvantages of the type of bone substitute are also to be considered. Ceramics of calcium phosphate are the main family of bone substitutes. They have different shape and size (granules, geometric shapes...). Their most important property is the bioactivity that is to say the ability to have exchanges with surrounding cells, tissues and fluids. They have a macroporosity which favors cell and bone invading. Phosphocalcic cements have the advantage to be injected percutaneously or by a minimal approach. Hardening happens in situ in a couple of minutes. Synthetic nanocrystalline hydroxyapatite hydrogels include nanocrystals identical to those of the bone and have a particular bioactivity. Bone allografts which have underwent treatments for microbiological safety avoid risk of infectious contamination while keeping the microporous structure of cancellous bone. They are now more used than cryopreserved allografts. Surgeons should be fully aware of properties, advantages and disadvantages of each type of bone substitute and should analyze the kind of bone loss before filling it. A personal series of 28 cases will illustrate this update on bone substitutes.