Comparative biomechanical study of a new transpedicular vertebral device and vertebroplasty for the treatment or prevention of vertebral compression fractures.

BACKGROUND: A comparative study was performed between a novel transpedicular implant (V-STRUT©, Hyprevention, France) and vertebroplasty. This study aims to assess the biomechanical efficacy of this implant in resurrecting and fortifying the osteoporotic vertebra following a vertebral body fracture.
METHODS: A total of 17 vertebrae from 3 human osteoporotic spine segments (T9-L5) were selected. Vertebral compression fractures were generated by eccentric compressive loading until a height reduction of 25%. Then the vertebrae were either fixed using vertebroplasty technique (control group; n = 8) or implanted with V-STRUT© implant combined with bone cement (device group; n = 9). A new compressive loading was performed in the same conditions. Maximal load and stiffness, as well as total energy to fracture were measured.
FINDINGS: Fracture force and energy to fracture were both increased either after V-STRUT© implantation or vertebroplasty compared to when the initial fracture was generated. Mean increase percentage between the initial value and the post-treatment value for each parameter were +77% vs +39% regarding fracture load and +126% vs +99% for energy to fracture, for the device group vs vertebroplasty group respectively. No pedicle fractures were observed in both groups, nor implant breaking or bending in the device group.
INTERPRETATION: These results show the ability of V-STRUT© combined with bone cement to reinforce the vertebral body strength, with an at least equivalent biomechanical performance as vertebroplasty. Further clinical investigation needs to be undertaken to demonstrate any clinical superiority of V-STRUT© over vertebroplasty.