Migration of a Cervical Artificial Disc Core: A Case Report of a Devastating Late-Occurring Complication

Study Design: Case report. Objective: Report a devastating cervical disc replacement complication underappreciated in the literature. Summary of Background Data: As many as 3000 patients receive single-level cervical disc replacements every year in the United States. Commonly acknowledged long-term complications may burden the patient ( e.g. , revision surgeries), but the potential for severe permanent neurological harm is not widely recognized. Differences in implant design impact this potential harm. Materials and Methods: We present a case report of a 28-year-old man, who had undergone cervical artificial disc replacement five years previously, thatpresented to our emergency department with sudden onset of quadriplegia after four days of worsening neck pain. Imaging revealed the artificial disc core displaced posteriorly into the spinal canal, confirmed during emergent surgical removal followed by anterior cervical fusion. Results: Despite successful removal of the migrated implant within 24 hours of his presentation with quadriplegia and revision with solid fusion, 14 months postrevision, the patient remains wheelchair-bound with complete C6-level quadriplegia. Physical therapy has improved his hand function, core strength, and range of motion. Conclusion: Core migration may cause catastrophic complications and occur years after implantation without a traumatic cause. This risk appears more likely with postoperative kyphotic device alignment and certain disc replacement implants. We found literature reporting similar incidents for two additional patients, although they had less drastic deficits. Our case report seeks to bring awareness to surgeons and patients of this long-term complication and shows the need for investigation into potential causes and prevention. Level of Evidence: Level V.