Previously, the anatomy and morphology of the thoracic vertebra and the pedicle in particular have been investigated in order to define a safer and reliable insertion technique. All but one study evaluated an intrapedicular pathway. In the one study on extrapedicular screws, it was concluded that the anatomy of posterior elements is too variable to allow for a standardized technique. In a previous study by the principle investigator, landmarks were defined in order to facilitate extrapedicular screw insertion. The advantage of this technique is the possibility to utilize screws with increased length and diameter.
Insertion is safer due to an increased distance to the spinal canal.
The range of motion between the noninstrumented and the instrumented construct will be measured and compared before and after fatigue testing. It is expected that the decrease of flexibility of the extrapedicular group is equal or higher than the intrapedicular group. P.F. Vertebroplasty, the percutaneous injection of bone cement into vertebral bodies, has recently been used to treat painful osteoporotic compression fractures. Early clinical results are encouraging, as pain relief is immediate and reliable, and the complication rate is low. Therefore, vertebroplasty is gaining increasing popularity for the treatment of osteoporotic spine patients.