A novel device with pedicular anchorage provides better biomechanical properties than balloon kyphoplasty for the treatment of vertebral compression fractures

Abstract

Purpose To compare the biomechanical behavior of vertebrae with vertebral compression fractures (VCF) treated by a novel system with pedicular anchorage (dowelplasty) versus balloon kyphoplasty. Methods Four cadaveric spines (T12-L5) were harvested, cleaned from soft tissues, and separated into vertebrae. Axial compressive loads were applied to each vertebra until a VCF was generated. Half of the vertebrae (n = 11) were instrumented using the “dowelplasty” system, consisting of a hollow titanium dowel anchored into the pedicle, through which a cannulated titanium nail is inserted and locked and through which cement is injected. The other half (n = 11) were instrumented using balloon kyphoplasty. Axial compressive loads were re-applied to each vertebra until fracture. Fracture load and fracture energy were calculated from load–displacement data for the pre- and post-treatment states. Results Compared to balloon kyphoplasty, dowelplasty granted greater net change in fracture load (373N; 95%CI,-331–1076N) and fracture energy (755Nmm; 95%CI,-563–2072Nmm). A sensitivity analysis was performed without L4 and L5 vertebrae from the dowelplasty group, since the length of the cannulated nails was too short for these vertebrae: compared to balloon kyphoplasty, dowelplasty granted an even greater net change in fracture load (680N; 95%CI,-96–1457N) and fracture energy (1274Nmm; 95%CI,-233–2781Nmm). Conclusion Treating VCFs with dowelplasty grants increased fracture load and fracture energy compared to the pre-treatment state. Furthermore, dowelplasty grants greater improvement in fracture load and fracture energy compared to balloon kyphoplasty, which suggests that dowelplasty may be a good alternative for the treatment of VCF. Level of evidence level IV.