1. Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized commercial reproduction of this slide is prohibited Supplemental PowerPoint Slides Primary Stiffness of a Modified Transforaminal Lumbar Interbody Fusion (TLIF) Cage With Integrated Screw Fixation: Cadaveric Biomechanical Study Keiler A1, Schmoelz W1, Erhart S1, Gnanalingham K2,3 1Department of Trauma Surgery, Medical University Innsbruck, Austria 2Department of Neurosurgery, Greater Manchester Neurosciences Centre, Salford Royal Foundation Trust, Manchester, UK. 3 Institute of Inflammation and Repair, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK.

2. P RIMARY STIFFNESS OF A MODIFIED TRANSFORAMINAL LUMBAR INTERBODY FUSION (TLIF) CAGE WITH INTEGRATED SCREW FIXATION – C ADAVERIC BIOMECHANICAL STUDY A biomechanical in vitro cadaver study was used to investigate the influence of an integrated screw fixation of a prototype TLIF cage on intersegmental stability.

3. The following paradigms were tested:  Intact spines  Destabilised spine (i.e. following discectomy and unilateral facetectomy)  The modified TLIF cage with and without integrated screw fixation, as a stand-alone model and with and without additional bilateral pedicle screws (PS).

4. Overall, the prototype TLIF cage with the integrated screw fixation only had very limited effect in reducing the range of motion (RoM) and providing stability. The present design of the prototype TLIF cage cannot be recommended as stand-alone implant. Modifications of the fixation screw on the cage might have a better stabilising effect.