Biomechanical Comparison of Augmentation Techniques for Insufficiency Fractures

Abstract

Biomechanical laboratory research. To compare 4 techniques for vertebral body insufficiency fracture repair by analyzing restoration of height, strength, and stiffness, and quantifying cement leakage. Current techniques for insufficiency fracture repair, restore prefracture strength, and all potentially have the complication of cement extrusion. To our knowledge, there is no information directly comparing different augmentation techniques. There were 4 osteoporotic/osteopenic fresh cadaveric spines' (T6-L5) vertebral bodies divided into the 4 groups and by levels (thoracic, thoracolumbar, lumbar). They were compressed to 25% of their initial height to simulate insufficiency fractures. Fixation techniques were vertebroplasty, osteoplasty (Interpore Cross Int., Irvine, CA), the Cavity Creation System (Synthes, Paoli, PA), and kyphoplasty (Kyphon, Sunnyvale, CA). Fractures were fixed using 3 cc of bone cement and recompressed. No significant difference was found in strength, height restoration, or stiffness among techniques (P < 0.05). Stiffness was significantly different in the lumbar levels between initial and post-fixation measurements (P < 0.05). Cement extrusion of 1 mL was seen in 1 vertebroplasty specimen. The 4 techniques equally restored strength and stiffness. No difference was seen in height restoration. Cement extrusion was significant in only 1 vertebral body, which may be attributable to the cement quantity.