96 patients with radicular symptoms due to single-level disc herniation and/or osteophytes of the cervical spine and scheduled for anterior cervical discectomy and fusion (ACDF) were randomized to undergo the procedure with either a polyetheretherketone cage filled with autograft, or a silicon nitride spacer containing porous silicon nitride without graft material. The study was conducted in order to determine if the silicon nitride spacer with porous silicon nitride in the graft space was an effective, noninferior alternative to standard PEEK cages with autograft. Neck Disability Index, Short Form-36, visual analog scale pain, operative outcomes, fusion rates, mean rotation on flexion/extension, device subsidence, and development of adjacent level symptoms was comparable between groups.