Comparing the Relative Stability of Posterior Fusion Constructs

Biomechanical testing was performed at the Barrow Neurological Institute evaluating the stability of various posterior constructs utilizing the Aspen Spinous Process Fixation System, Concero Facet Screws and/or pedicle screws. The testing occurred on seven human cadaveric L3-S1 specimens with a mean age 47 years with mean bone density 0.884 g/cm2. Pure moments (±7.5 Nm) were applied in each plane while recording angular motion optoelectronically. Each specimen was tested using an intact specimen followed by five different constructs.

Considerations for Posterior Surgery

• Within the results of this study, the Aspen device coupled with Concero facet screws, demonstrated range of motion comparable to more invasive bilateral pedicle screws-rods
• Due to comparable relative stability to bilateral pedicle screws-rods, the Aspen device, coupled with Concero facet screws may be a viable option for posterior fusion surgery
• Allowing comparable ROM to bilateral pedicle screws, the Aspen implant and Concero facet screws may offer a less invasive alternative fixation method

Study Results

• Each construct was demonstrated to be effective at reducing angular range of motion (ROM)
• The Aspen implant with bilateral Concero facet screw provided overall stability that was equivalent to bilateral pedicle screw (p>0.99, RM-ANOVA/Holm-Sidak)

To learn more about the biomechanical testing results, please contact your local Lanx representative.