[Stabilization of the osteoporotic spine from a biomechanical viewpoint]

Abstract

The altered trabecular structure of the osteoporotic spine leads to an increased vulnerability of its biomechanical characteristics and reduction of load resistance. Therefore, any surgical procedure must account for these circumstances. In cement-augmented vertebrae, both the overall stability and load transfer to the adjacent structures are influenced by a variety of factors. This has been demonstrated by different findings regarding volume, special characteristics, choice of approach and application, as well as distribution of the cement within the vertebral body. Independent of the well-known good clinical results, these features leave the discussion regarding the most appropriate form of cement-augmenting technique open. In cases where implants are required, there are increasing data to allow for an appropriate choice of stabilizing devices to fit the biomechanical demands in poor bone quality. Thereby, multilevel instrumentation, additive stabilization techniques, cement-augmented pedicle screws and adapted implant designs ensure and increase patient safety. However, regardless of the procedure chosen to stabilize the osteoporotic spine, reconstruction of the column profile appears to be of pre-eminent importance.