Long-term Follow-Up Results of Dynamic Cervical Implant in Patients with Cervical Disk Diseases: Compared with Arthroplasty

Background Arthroplasty has been proven to be a safe and effective treatment for patients with cervical degenerative disk disease (DDD). Dynamic Cervical Implant (DCI) has emerged as a novel implantation device for cervical DDD. This study aimed to compare the outcomes of these procedures after 5 years of follow-up in the DCI and arthroplasty groups. Methods This study retrospectively enrolled 79 consecutive cervical DDD patients with 41 DCI and 47 prostheses implanted. Radiographs were analyzed for intervertebral height and range of motion (ROM). Neural function of the patients was assessed using the Neck Disability Index score, visual analog scale, Japanese Orthopaedic Association score and 36-Item Short Form Survey. Results The DCI group had statistically lesser flexion/extension and bilateral bending ROM than the arthroplasty group at the operated level(s) ( p < 0.05). The DCI group but not the orthoplast group showed improved lordotic alignment of C2–C7 and operated functional spinal unit ( p < 0.05). No statistical difference was observed in the neural function of the two groups. Heterotopic ossification was found in 7 and 14 patients in the DCI and arthroplasty groups, respectively. Conclusion The 5-year follow-up results were comparable between the two groups. We believe that DCI implantation is a safe and effective procedure and could possibly become an alternative treatment for cervical DDD.