Anterior Cervical Plating Enhances Arthrodesis after Discectomy and Fusion with Cortical Allograft

Abstract

ABSTRACT OBJECTIVE Anterior plate fixation has gained widespread acceptance for the treatment of cervical spondylosis, theoretically enhancing the rate of arthrodesis. There are few studies comparing fusion rates after anterior cervical discectomy and fusion (ACDF) with and without a plate. The purpose of this study was to evaluate the efficacy of anterior cervical plating for fusion enhancement after one- and two-level ACDF with cortical allograft. METHODS A retrospective review was performed with 251 patients who underwent one- or two-level ACDF with cortical allograft and plate stabilization between 1993 and 1999. An independent surgeon reviewer determined fusion status and complications. A successful fusion was defined by the absence of lucency around the graft, evidence of bridging bone between the endplate and the graft, and the absence of movement on dynamic imaging scans. Follow-up data, ranging from 9 months to 3.6 years, were available for 233 patients. A control group of 289 patients who underwent ACDF without plating was described in a previously published report by the senior author (RWH). Therefore, a total of 540 patients were evaluated for determination of the efficacy of anterior cervical plating with cortical allograft bone. Statistical significance was determined by χ2 test. RESULTS The fusion rates for one- and two-level ACDF with anterior fixation were 96 and 91%, respectively, compared with 90 and 72% for one- and two-level ACDF without anterior fixation. The observed increases in fusion rates for both one- and two-level procedures proved to be statistically significant (P < 0.05). There were no recorded infectious, neurological, or graft-related complications among the cohort treated with anterior cervical plating. Compared with the results for the cohort treated without anterior cervical plates, there was a statistically significant decrease in the graft-related complication rate with the application of plates (P < 0.001). Two patients who received plates were noted to have adjacent-segment degenerative changes that required surgical intervention. No hardware fractures were noted; however, one patient was noted to have a single displaced screw, without clinical consequences. CONCLUSION The use of anterior cervical plating after one- and two-level ACDF with allograft cortical bone significantly enhanced arthrodesis. The improved fusion rate and negligible complication rate associated with anterior cervical plating are compelling factors justifying its use in the treatment of cervical spondylosis.