The effect of cage type on local and total cervical lordosis restoration and global spine alignment in single-level anterior cervical discectomy and fusion based on EOS® imaging: A comparison between standalone conventional interbody polyether ether ketone cage and integrated cage and plate (Perfect-C®)

Background: There is a small level of evidence regarding the alterations in global spine alignment following the restoration of cervical lordosis using anterior cervical discectomy and fusion (ACDF). Different cage types are available to restore cervical lordosis through ACDF. In this study, we evaluate the impact of two types of these cages on local and global spine alignments. Patients and Methods: Thirty-two patients with a mean age of 46 ± 10 who underwent ACDF for cervical disc herniation were included in this retrospective study. Patients were divided according to their cage type into two groups, 17 patients with standalone conventional polyether ether ketone cages and 15 patients with integrated cage and plate (ICP) (Perfect-C®). Cervical alignment and global spine alignment were evaluated on the pre- and post-operative EOS® images. Results: Three months after the ACDF, total cervical lordosis correction was higher in patients with ICP (P = 0.001), while the local cervical lordosis correction was not significantly different between conventional cages and prefect-C cages (P = 0.067). Lumbar lordosis and pelvic tilt change were significantly higher among patients with Perfect-c cages (P = 0.043). Conclusion: In patients undergoing ACDF, alignment of the global spine changes along with the restoration of the cervical spine. Cage type affects this association, mainly through the compensatory alteration of pelvic tilt.