Abstract: BACKGROUND: Plate fixation has traditionally been the method of choice in anterior cervical discectomy and fusion procedures. In recent years, the Zero-profile self-stabilizing fusion device (ROI-C, LDR, Troyes, France) has gained popularity in anterior cervical discectomy and fusion; however, its potential to replace conventional plate fixation remains a subject of debate.
OBJECTIVE: To compare the effectiveness and complications associated with single-level cervical spondylotic myelopathy treated via anterior cervical discectomy and fusion using a self-adjustable cage (ROI-C) versus traditional plate fixation.
METHODS: A retrospective analysis was conducted on 63 patients diagnosed with single-level cervical spondylosis who underwent anterior cervical discectomy and fusion at Eastern District of Qingdao Municipal Hospital between January 2019 and July 2023. Based on the type of internal fixation employed, patients were categorized into two groups: ROI-C group (22 cases utilizing ROI-C fixation) and plate group (41 cases employing traditional plate and screw fixation). Various parameters were compared between both groups, including operation time, intraoperative blood loss, Japanese Orthopaedic Association Scores, Visual Analogue Scale scores, Neck Disability Index, C2-7 cobb angle, T1 Slope, and intervertebral space height recorded preoperatively as well as immediately, 3, 6, and 12 months postoperatively. Furthermore, swallowing function outcomes and instances of adjacent segment degeneration were evaluated across both groups.
RESULTS AND CONCLUSION: (1) Compared with the plate group, the operation time was significantly shorter, and intraoperative blood loss was notably lower in the ROI-C group (P < 0.05). (2) The Japanese Orthopaedic Association Scores, C2-7 cobb angle, and intervertebral space height immediately, 3, 6, and 12 months postoperatively, and T1 Slope 3 and 6 months postoperatively were significantly increased compared with those preoperatively (P < 0.05). Visual Analogue Scale scores and Neck Disability Index were decreased immediately, 3, 6, and 12 months postoperatively (P < 0.05). In the plate group, the Japanese Orthopedic Association score, C2-7 Cobb angle, intervertebral space height, and T1 Slope immediately, 3, and 6 months after surgery were significantly increased compared with those before surgery. The visual analog scale score and Neck Disability Index immediately, 3, 6, and 12 months after surgery were significantly decreased compared with those before surgery (P < 
0.05). (3) The incidence of dysphagia in the ROI-C group (0%) was significantly lower 3 months after surgery than in the plate group (17%) (P=0.041). 12 months after surgery, the incidence of adjacent segment degeneration was 5% (1/22) in the ROI-C group and 7% (3/41) in the plate group. Both groups had significantly lower intervertebral heights of the upper and lower adjacent segments compared to the immediate postoperative period, with the plate group showing a greater decrease in intervertebral height than the ROI-C group (P < 0.05). (4) This suggests that both ROI-C and traditional plate and screw fixation for the treatment of single-segment cervical spondylosis can effectively improve neurological function, relieve pain, and enhance cervical biological parameters. However, the ROI-C group had a shorter operation time, less blood loss, and a lower incidence of postoperative dysphagia, with less impact on adjacent segment degeneration.

Key words: ">single-segment cervical spondylosis, ROI-C, anterior cervical surgery, sagittal parameter, adjacent segment degeneration, dysphagia