BackgroundThe purpose of this study was to investigate the clinical outcomes of anterior cervical discectomy and fusion (ACDF) or anterior cervical corpectomy and fusion (ACCF) as a revision surgery for adjacent segment disease (ASD) after primary surgery.MethodsThere were 35 patients who underwent anterior cervical spine surgery for symptomatic recurrent radicular or myelopathic symptoms from ASD. According to the ASD involved levels superior or inferior to the previous operated level, patients were divided into two groups: superior and inferior groups. The patients were also grouped into ACDF and ACCF groups by who received ACDF or ACCF as revision surgery for ASD. Clinical evaluations were performed preoperatively and repeated at 2 years after operation.ResultsIn this study, a total of 35 patients with a minimum of 2 years of follow-up data were available for analysis. There were 20 patients in the superior group and 15 patients in the inferior group according to the ASD developed at levels. Of these 35 patients, according to the treatment method, 12 patients were in the ACCF group and 23 patients were in the ACDF group. The Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and visual analogue scale (VAS) on arm pain and neck pain scores demonstrated significant improvement compared to the preoperative scores in both groups (superior and inferior groups or ACDF and ACCF groups) (P < 0.05). However, there was no difference between the two groups (superior and inferior groups or ACDF and ACCF groups) (P > 0.05).ConclusionsAccording to our study, both superior and inferior adjacent-level groups together with ACDF and ACCF groups maintained favorable clinical results on patients who underwent one-level ACDF for symptomatic new radicular or myelopathic symptoms.