Fig. 1. (A) 10 months postoperative lateral radiograph of a 47 years old male patient who underwent one-level ACDF (C4-5) with autograft (Bridwell fusion grade I). (B) 12 months postoperative lateral radiograph of a 54-year-old female patient who underwent two-level ACDF (C3-4, C4-5) with allograft (Bridwell fusion grade III).