Screw Insertion Damage Effects on Nitinol Corrosion Resistance in Spinal Fixation Plates

Nitinol is commonly used as a retention clip to prevent backout of fixation screws in spinal anterior cervical plates (ACP). During implantation, however, there is metallic contact between the screw and retention clip. The effects of this surface damage on corrosion resistance of the Nitinol clip have not been thoroughly investigated and may be dependent on the level of screw-clip interference in the construct design. Therefore, the goal of this study is to characterize the effects on the Nitinol corrosion resistance using varying levels of screw-clip interference in a modified ACP assembly.