Fig. 2.

 A 48-year-old female patient underwent single-level ACDF due to C4/5 disc herniation. A mixture of bone dust and morselized bone was used as an n-HA/PA66 cage-filling material during the operation. A Preoperative lateral radiograph of the cervical spine showing narrowing of the C4/5 disc space. B Postoperative lateral radiograph showing that the n-HA/PA66 cage increased the FSH, SSA, and C2–7 lordotic angle. C, D Flexion-extension lateral radiographs showing fusion at the 3-month and 6-month follow-ups. E, F Lateral radiographs showing mild cage subsidence at the 1-year and final follow-ups; the FSH, SSA, and C2–7 lordotic angle remained stable. G Three-dimensional CT at the 28-month follow-up time showing grade 5 fusion