TY - JOUR A2 - Demetriades, Andreas K. AU - Yeager, Matthew S. AU - Cook, Daniel J. AU - Cheng, Boyle C. PY - 2015 DA - 2015/08/17 TI -In VitroComparison of Dynesys, PEEK, and Titanium Constructs in the Lumbar Spine SP - 895931 VL - 2015 AB - Introduction. Pedicle based posterior dynamic stabilization systems aim to stabilize the pathologic spine while also allowing sufficient motion to mitigate adjacent level effects. Two flexible constructs that have been proposed to act in such a manner, the Dynesys Dynamic Stabilization System and PEEK rod, have yet to be directly compared in vitroto a rigid Titanium rod. Methods. Human lumbar specimens were tested in flexion extension, lateral bending, and axial torsion to evaluate the following conditions at L4-L5: Intact, Dynesys, PEEK rod, Titanium rod, and Destabilized. Intervertebral range of motion, interpedicular travel, and interpedicular displacement metrics were evaluated from 3rd-cycle data using an optoelectric tracking system. Results. Statistically significant decreases in ROM compared to Intact and Destabilized conditions were detected for the instrumented conditions during flexion extension and lateral bending. AT ROM was significantly less than Destabilized but not the Intact condition. Similar trends were found for interpedicular displacement in all modes of loading; however, interpedicular travel trends were less consistent. More importantly, no metrics under any mode of loading revealed significant differences between Dynesys, PEEK, and Titanium. Conclusion. The results of this study support previous findings that Dynesys and PEEK constructs behave similarly to a Titanium rod in vitro. SN - 2090-3464 UR - https://doi.org/10.1155/2015/895931 DO - 10.1155/2015/895931 JF - Advances in Orthopedics PB - Hindawi Publishing Corporation KW - ER -