Translating versus nontranslating cervical plates

Abstract

Several anterior cervical plating systems recently have been designed to allow for controlled movement between fused vertebrae to increase load sharing across an interbody graft. The purpose of this study was to determine whether dynamic translating cervical plates are associated with improved radiographic outcomes as compared with variable-angle screw plates in patients undergoing anterior cervical discectomy and fusion (ACDF). We retrospectively reviewed medical records and postoperative radiographic films (3, 6, and 12 months) of patients who underwent single and multilevel ACDF using either dynamic translating or variable-angle plates. Data were analyzed relative to mean displacement of vertebrae, number of vertebrae fused, fusion status, and Cobb angle. Of the 50 patients in this study, 24 received translating plates and 26 received variable-angle plates. Radiographic outcomes were similar between the two groups when looking at mean displacement of vertebrae, number of vertebrae fused, and fusion status. We observed a higher rate of Cobb angle change greater than 3° with translating plates. Additionally, we observed a trend toward loss of lordosis in the translating group and increased lordosis in the variable-angle group. Our study failed to confirm our hypothesis that translating plates are associated with higher fusion rates than variable-angle plates. A higher rate of Cobb angle change along with a decrease in mean Cobb angle was observed in the translating group. Loss of lordosis in the translating group may suggest a negative impact with these plates, including less ideal alignment of the spine.