Bone substitutes in vertebroplasty

Vertebroplasty - percutaneous cement augmentation of vertebral bodies - is an efficient procedure for the treatment of painful vertebral fractures in osteoporosis. At the present time, polymethylmethacrylate (PMMA) is the onl y available cement with reports of clinical application and experience. The material is easy to handle, the radiopacity can be adapted by adding contr ast dye, and it is mechanically efficient. Composite cements (acrylic cemen ts in conjunction with ceramics) are bioactive, highly radiopaque, and feat ure excellent mechanical properties. One such cement, Cortoss, is currently undergoing clinical trials for vertebroplasty and has so far been shown to be a potentially valuable alternative to PMMA. Several in vitro studies wi th injectable calcium phosphate (CaP) cements show their feasibility and me chanical effectiveness. Animal studies confirm their biocompatibility and o steoconductivity. However, handling problems and the limited radiopacity of these cements currently preclude their clinical use.