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+®) 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®). 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° preop to 3.0° 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+® 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.