111 patients with degenerative cervical disc disease were randomized to surgery through either cervical disc arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF). The purpose of this study was to compare clinical efficacy and cervical spine range of motion (ROM) at a minimum of 48 months after surgery. The results indicated no significant differences between groups in clinical outcome scores, although favourable spinal motion with CDA. In particular, cervical-spine ROM and ROM of the index, superior, and inferior spinal levels was better restored with CDA. Additionally, 4 patients of the ACDF group underwent adjacent segment-related reoperation. Heterotopic ossification was observed in 18 patients of the CDA group.