Comparison of plate-cage construct and stand-alone anchored spacer in the surgical treatment of three-level cervical spondylotic myelopathy: a preliminary clinical study

Although stand-alone cages were advocated to be superior to plate-cage construct (PCC) because of comparable clinical outcomes and fewer plate-related complications, cage dislocation and subsidence were frequently mentioned in multilevel fusion. There are some concerns about whether these issues can be effectively prevented in multilevel anterior cervical discectomy and fusion (ACDF) by stand-alone anchored spacer (SAAS).The aim was to compare clinical outcomes, radiologic parameters, and complications of PCC and SAAS in the treatment of three-level cervical spondylotic myelopathy (CSM).This was a retrospective comparative study.A total of 38 consecutive patients with three-level CSM (ACDF with PCC, 20 patients; ACDF with SAAS, 18 patients) were reviewed.Clinical outcomes were assessed using Japanese Orthopaedic Association and Neck Disability Index. The radiologic evaluations included cervical alignment (CA), segmental angle (SA), postoperative curvature loss (PCL), and incidence of subsidence.All the aforementioned parameters were compared before and after surgery between two groups. Besides, the aforementioned results were also compared between the two groups. The complications were also recorded.The mean follow-up period was 30.3 months. No significant differences were observed in clinical outcomes between the two groups (p>.05). Additionally, no significant differences existed in fusion rate between the two groups. There were significant differences in PCL of SA and CA and correction of SA between the two groups (p<.05). Besides, the incidence of subsidence (9 of 54 levels, 16.7%) was recorded in the SAAS group, and the potential of SAAS to reduce the incidence of postoperative dysphagia was not proven. No other complications were observed in this study.In the surgical treatment of three-level CSM, PCC is superior to SAAS in correction and maintenance of SA and avoiding cage subsidence, although the technique of ACDF with SAAS yielded encouraging clinical outcomes and high fusion rate.