gms | German Medical Science

Objective: Anterior cervical discectomy and fusion (ACDF) with a cervical plate allows for decompression of neural structures and maintenance or correction of cervical alignment. Cervical lordosis has been correlated with good clinical outcomes and it is clear that segmental kyphosis is detrimental to clinical outcome and predisposes patients to adjacent segment degeneration. The radiographic change in cervical alignment using lordotic and non-lordotic grafts for ACDF has already been reported. The role of the anterior cervical plating on these postoperative radiographic paramaters has yet to be assessed.

Methods: A retrospective review of 59 consecutive patients were separated into two groups depending on the allograft and the cervical plating system that was used. All patients underwent a 1,2 or 3 level ACDF for cervical spondylosis using either a translational plating system with a 2-3° lordotic allograft or a rotational plating system with a 6° lordotic allograft. Plain neutral radiographs were assessed preoperatively, immediately after surgery and at the most recent follow-up. The measured radiographic parameters included C2-7 lordosis, segmental sagittal alignment (SSA), sagittal vertical alignment (SVA), adjacent SSA, disc height, adjacent segment ossification, plate to disc space distance (PDSD), height of fusion, fusion rate and implant migration.

Results: There were thirty patients in group 1 and twenty-nine patients in group 2. A 1-level ACDF was performed in 10 and 9 patients respectively, a 2-level ACDF was performed in 14 and 15 patients respectively, and 3-level ACDF was performed in 6 and 5 patients respectively. The mean follow-up was 14.8 and 13.1 month, respectively. The immediate postoperative and most recent follow-up radiographs revealed improvement of C2-7 lordosis, SSA, and adjacent SSA in both groups. Further, a worsening of the SVA, a decrease in fusion height, an increase in adjacent segment ossification, and a loss of PDSD were seen in both groups. After initial improvement on the first postoperative radiograph, the trend favored deterioration on the most recent radiograph in both groups. There was no significant difference in the improvement or worsening of these radiographic parameters between both groups. A higher rate of screw pull out was seen using a rotational construct. The fusion rate was 98.2% and 92.6%, respectively.

Conclusion: Performing an ACDF with allograft and either a dynamic translational or rotational plating systems provides adequate correction of cervical alignment. There is no significant difference in improvement or worsening of radiographic parameters in either group. In both groups, these parameters worsened at the time of the second postoperative radiograph; however, these changes were still an improvement from the preoperative radiographs.