Fig. 2

Representative cervical X-ray images of Carmen and Zero-P implant treated patient. a–c Single-level male patient treated with Carmen device, the segmental Cobb angle of C5–C6 changed from 11-degree lordosis to 18-degree lordosis after the surgery, and reached 20-degree at one-year follow-up, as well as the C2–C7 Cobb angle. d, e Single-level male patient treated with Zero-P device, the segmental Cobb angle of C5–C6 changed from 7-degree lordosis to 9-degree lordosis after the surgery, and decreased to 4-degree at one-year follow-up, as well as the C2–C7 Cobb angle (15-degree preoperative, 20-degree postoperative and 15-degree at one-year follow-up)