Biomechanics of an Expandable Lumbar Interbody Fusion Cage Deployed Through Transforaminal Approach

• Published in: International journal of spine surgery 2017-01, Vol.11 (4), p.24-24
• Main Authors: Mica, Michael Conti, Voronov, Leonard I, Carandang, Gerard, Havey, Robert M, Wojewnik, Bartosz, Patwardhan, Avinash G
• Format: Article
• Language: English
• ISSN: 2211-4599; 2211-4599
• DOI: 10.14444/4024

A novel expandable lumbar interbody fusion cage has been developed which allows for a broad endplate footprint similar to an anterior lumbar interbody fusion (ALIF); however, it is deployed from a minimally invasive transforaminal unilateral approach. The perceived benefit is a stable circumferential fusion from a single approach that maintains the anterior tension band of the anterior longitudinal ligament.The purpose of this biomechanics laboratory study was to evaluate the biomechanical stability of an expandable lumbar interbody cage inserted using a transforaminal approach and deployed in situ compared to a traditional lumbar interbody cage inserted using an anterior approach (control device). Twelve cadaveric spine specimens (L1-L5) were tested intact and after implantation of both the control and experimental devices in two (L2-L3 and L3-L4) segments of each specimen; the assignments of the control and experimental devices to these segments were alternated. Effect of supplemental pedicle screw-rod stabilization was also assessed. Moments were applied to the specimens in flexion-extension (FE), lateral bending (LB), and axial rotation (AR). The effect of physiologic preload on construct stability was evaluated in FE. Segmental motions were measured using an optoelectronic motion measurement system. The deployable expendable TLIF cage and control devices significantly reduced FE motion with and without compressive preload when compared to the intact condition (p