Anterior cervical dynamic implants led to long-term decreases in motion preservation, according to a study in the February 2025 issue of The Spine Journal.
Researchers assessed patients with degenerative cervical disorders who had an anterior cervical discectomy and dynamic cervical implant implantation between May 2012 and August 2020. They measured clinical outcomes with the modified Japanese Orthopedic Association, visual analog scale scores and patient-reported satisfaction rates.
Ninety-two patients were included. Revision surgery was not required for instrumentation failure or adjacent segment disease for any of the patients in the follow-up period. But at the one-month follow up period, segmental range of motion saw a decrease postoperatively, along with more decrease at the final follow-up.
The study concluded that "At the long-term follow-up, a high incidence of heterotopic ossification, along with varying degrees of subsidence and migration of the prosthesis, were observed in most patients. As the motion preservation capability of the ACDI gradually diminishes, delayed intervertebral autofusion becomes a more likely outcome compared to motion sparing."