Does anterior plating maintain cervical lordosis versus conventional fusion techniques? A retrospective analysis of patients receiving single-level fusions.

A retrospective review of medical records and radiographs of patients receiving anterior cervical discectomy and fusion (ACDF) without anterior plating and with anterior plating was performed. The objective of the study was to determine whether a difference exists in cervical lordotic alignment between subjects undergoing single-level ACDF with and without anterior cervical plating instrumentation for symptomatic cervical disc disease. Collapse or settling of grafted bone into the vertebral endplates with resulting kyphotic deformity of the cervical spine is a commonly described complication of anterior discectomy and fusion. Despite the increasing use of instrumentation for the treatment of cervical spine injuries and degenerative conditions, little is known regarding lordotic alignment of the cervical spine in patients who receive plating instrumentation compared with conventional fusion without plating. Accumulating evidence suggests that plating is superior to non-plating techniques in patients with multiple level cervical disc lesions in regard to fusion, return to work rates, and complication rates; however, little is known about maintenance of lordotic curve alignment in single- and multiple-level procedures. Neutral lateral cervical radiographs of 57 patients who underwent single-level ACDF between 1994 and 1999 with anterior screw plates (n = 26), and conventional single-level fusion without anterior screw plates (n = 21) were retrospectively assessed. Measurements were made on weight-bearing lateral cervical radiographs to assess overall sagittal spinal alignment and intersegmental sagittal alignment at the surgical site before surgery, immediately after surgery, 4 to 12 weeks after surgery, and 12+ months after surgery. The average magnitude of overall lordosis measured between C2 and C7 decreased 4.2 degrees in the non-plated group, while being preserved in the plated group. This finding did not reach statistical significance in the long-term follow-up. At the surgical site, the segmental contribution to lordosis decreased an average 2.5 degrees in the non-plated group versus an increase of 5.67 degrees in the plated group, and this finding was statistically significant between groups measured at all pre- and postoperative visits (p < 0.01). On average, the plating procedure resulted in preserving overall lordosis while increasing the magnitude of segmental lordosis at the surgical site. In comparison, the conventional method resulted in a net loss of overall lordosis and segmental lordosis at the surgical site.