Comparison between plate cage system and stand-alone cage in the treatment of cervical spondylotic myelopathy patients with cervical kyphosis: clinical and radiographic outcomes.

BACKGROUND

To compare mid-term outcomes of plate cage systems (PC) vs. stand-alone cages (SA) in two-level ACDF for cervical spondylotic myelopathy (CSM) with cervical kyphosis, and to assess the influence of preoperative segmental kyphosis reducibility on sagittal alignment maintenance.

METHODS

This retrospective cohort analyzed 130 patients (SA = 64, PC = 66) with ≥24-month follow-up. Radiographic parameters (cervical lordosis [CL], fusion segmental lordosis [FSL], disc wedge, C2 SVA) and clinical outcomes (NDI, VAS, JOA, EQ-5D, dysphagia) were assessed preoperatively, postoperatively, and at final follow-up. Patients were stratified based on preoperative reducibility of segmental kyphosis.

RESULTS

Both groups showed comparable clinical improvement (p < 0.05) and fusion rates (93.8% SA vs. 95.4% PC, p = 0.667). SA had shorter operation time (78.0 ± 11.5 vs. 86.6 ± 12.5 min, p < 0.001), less blood loss (193.0 ± 85.6 vs. 256.7 ± 110.3 mL, p < 0.001), and lower dysphagia incidence (12.5% vs. 20.3%, p = 0.014). However, the PC group demonstrated superior maintenance of cervical sagittal alignment in CL (13.6° ± 0.9° vs. 12.3° ± 2.4°, p < 0.001), FSL (13.2° ± 1.2° vs. 11.9° ± 2.9°, p = 0.001), and disc wedge (10.2° ± 1.3° vs. 8.9° ± 2.6°, p < 0.001) at follow-up, particularly in patients with non-reducible kyphosis (p < 0.05).

CONCLUSION

SA offers operative efficiency advantages, while PC is more effective in maintaining sagittal alignment, especially in rigid kyphosis. PC is recommended for patients with non-reducible cervical kyphosis.