Zero-Profile Anchored Spacer (ROI-C) in the Treatment of Cervical Adjacent Segment Disease.

 Self-locking stand-alone cages have increasingly been used in anterior cervical discectomy and fusion (ACDF) cervical degenerative disc disease. We studied clinical and radiological outcomes of patients who underwent zero-profile anchored spacer (ROI-C)-assisted ACDF without anterior plate fixation in cervical adjacent segment disease.  Fifteen patients suffering from cervical adjacent segment disease with various symptoms, such as radiculopathy, myelopathy, or both, were retrospectively evaluated. The cervical adjacent segment disease was confirmed by plain radiographs and magnetic resonance imaging. The patients underwent radiological evaluation to assess cervical curvature, intervertebral height, fusion, and subsidence. Clinical assessment was graded using a visual analog scale, Modified Japanese Orthopedic Association score, and the Neck Disability Index.  There were 19 levels of operation. Single-level ACDF was performed in 11 patients and two level in 4 patients. In the postoperative period, our study revealed significant improvement in the clinical outcome. The cervical curvature and intervertebral height were significantly improved at 12-months follow-up (  < 0.05). The fusion rate was 100%, whereas subsidence occurred in 5.3% but produced no symptoms. Of the 19 operated segment, 2 (5.3%) from 38 VerteBRIDGE plates had breakage. There was only one case of mild dysphagia, which resolved in less than 2 weeks.  This study indicates that zero-profile anchored spacer (ROI-C) in the treatment of cervical adjacent segment disease provides improvement of clinical outcomes, restoration of lordosis, high fusion rate, and low incidence of dysphagia. However, subsidence and breakage of VerteBRIDGE plate occurred in 5.3% cases, but did not cause clinical symptoms.