Dong L, et al. - Authors evaluated the overall condition of adjacent segment of cervical disk arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF). Results demonstrated that the advantages of CDA were lower adjacent segment degeneration (ASDeg), adjacent segment disease (ASDis), adjacent segment reoperation and adjacent segment motion, and higher cervical ROM, compared with ACDF. Nonetheless, between upper and lower adjacent segment ROM/ASDeg using the same surgery, no statistical difference was noted.