Complications in cervical total disc arthroplasty

Cervical total disc arthroplasty (CTDA) is an alternative to cervical fusion when addressing single level cervical disc disease and attempts to restore normal disc height and preserve motion, theoretically decreasing rates of adjacent segment disease (ASD) and symptomatic pseudoarthrosis. Although safe and effective, CTDA has a unique complication profile particularly in regard to long-term complications. Approach related complications are similar to anterior cervical discectomy and fusion (ACDF) and include injury to surrounding vascular, digestive, and neurologic structures. To achieve anatomic positioning, CTDA requires vertebral endplate cartilage removal and osseous preparation which can lead to endplate fracture, salvage fusion, or component malpositioning. Long term complications include heterotopic ossification (HO), implant subsidence, ASD requiring surgical intervention, and implant migration or translation. Although HO reduces motion at the prosthesis site, it does not appear to worsen clinical outcomes in most cases. Evidence is still conflicting regarding ASD when comparing ACDF to CTDA, however, the most recent evidence suggests a lower rate of development with CTDA.