Magnetic resonance imaging evaluation of intervertebral test spacers: an experimental comparison of magnesium versus titanium and carbon fiber reinforced polymers as biomaterials (Retracted article. See vol. 184, pg. 263, 2015)

Introduction Intervertebral spacers are made of different materials, which can affect the postfusion magnetic resonance imaging (MRI) scans. Susceptibility artifacts, especially for metallic implants, can decrease the image quality. This study aimed to determine whether magnesium as a lightweight and biocompatible metal is suitable as a biomaterial for spinal implants based on its MRI artifacting behavior. Materials and methods To compare artifacting behaviors, we implanted into one porcine cadaveric spine different test spacers made of magnesium, titanium, and CFRP. All test spacers were scanned using two T1-TSE MRI sequences. The artifact dimensions were traced on all scans and statistically analyzed. Results The total artifact volume and median artifact area of the titanium spacers were statistically significantly larger than magnesium spacers (P < 0.001), while magnesium and CFRP spacers produced almost identical artifacting behaviors (P > 0.05). Conclusion Our results suggest that spinal implants made with magnesium alloys will behave more like CFRP devices in MRI scans.