209 patients with one-level symptomatic cervical disc disease were randomized to undergo cervical artificial disc replacement (C-ADR) or anterior cervical discectomy and fusion (ACDF) for the purpose of determining whether C-ADR was associated with a reduction in radiographic adjacent level degeneration (ALD) and superior disc range of motion (two postoperative complications commonly associated with standard ACDF). Significantly lower progression of ALD was found in C-ADR patients when compared ACDF patients, and severity of ALD in C-ADR patients was found to have significant inverse relations to index disc range of motion when assessed at final follow-up.