Radiological analysis of 37 segments in cervical spine implanted with a peek stand-alone device, with at least one year follow-up

Background. High incidence of subsidence in cervical stand-alone cages was reported in the literature. Purpose. The goal of this study was to assess the radiological outcomes of a PEEK anchored stand-alone cage (MC+(R)) with a minimum of 1 year follow-up. Study design. A retrospective radiological evaluation. Patient sample. The study was conducted in 4 hospitals and involved 28 patients (37 levels) treated by ACDF (Anterior Cervical Discectomy and Fusion) for spondylotic radiculopathy and/or myelopathy. Outcome measures. We analyzed fusion, disc height, cage or anchor micro plate migration, discal and segmental lordosis and subsidence. Methods. All the patients were controlled at least one year after surgery with an average of 31 months. Antero-posterior and lateral X-rays were performed pre-operatively, immediate post-operatively, and at final follow up. The different radiographic measurements were performed with the assistance of software (SpineView (R)). CT-scans were performed for each case at final follow-up to assess the fusion. Results. No migration or breakage was reported for either the cage or the anchor micro plate. The fusion rate was 94.1% at the final follow-up. No subsidence was observed. The disc height increased between preop and final follow-up from 23.3% to 44.3%, from 22.1% to 35.1% and from 38.3% to 51.5% for anterior, posterior and midline disc height respectively. Mean Functional Spinal Unit Lordosis increased from 0.9 degrees preop to 3.0 degrees at final follow-up. No new kyphotic situation could be noticed. At the final follow-up, 96% of the patients stated they would undergo the procedure again. Conclusion. With a high rate of proven fusion, restoration of disc height and spinal alignment in most cases, and absence of subsidence or migration, our radiological results with MC+(R) at more than 1 year of follow-up show the implanted device to be safe and effective for use in treating degenerative conditions of the cervical spine.