Increased fusion rates with cervical plating for two-level anterior cervical discectomy and fusion

Study Design. A retrospective review of all patients surgically treated wit h a two-level anterior cervical discectomy and fusion with and without ante rior plate fixation by a single surgeon. Objectives, To compare the clinical and radiographic success of two-level d iscectomy and the effect of anterior cervical plate fixation. Summary of Background Data. Prior studies of multisegment fusions have show n decreased fusion rates correlating with the number of increased levels. T he use of anterior plates for single-level cervical fusions is controversia l. However, their use in multilevel fusions may be warranted because of the increased pseudarthrosis rates. Methods. Over a g-year period, 60 patients were treated surgically with a t wo-level anterior cervical discectomy and fusion by the senior author. Thir ty-two patients had cervical plates, and 28 underwent fusions without plate s, These patients were followed for an average of 2.7 years. Clinical and r adiographic follow-up evaluations were performed. Results. Of the 60 patients, 7 had a pseudarthrosis. The pseudarthrosis rat es were 0% for patients with plating and 25% for those with no plating. Thi s difference was statistically significant (P = 0.003). No correlation of p seudarthrosis with gender, age, level of surgery, history of tobacco use, o r the presence of prior anterior surgery was found. There was significantly less graft collapse (P = 0.0001) in the patients without plates in whom ps eudarthrosis developed (1.4 mm) than in those who had fusions with plates ( 0.3 mm). The amount of kyphotic deformity of the fused segment was 0.4 degr ees in patients with plating compared with 4.9 degrees in those without pla ting who developed a pseudarthrosis (P = 0.0001). Conclusions. The addition of plate fixation for two-level anterior cervical discectomy and fusion is a safe procedure with no significant increase in complication rates. The pseudarthrosis rates are significantly higher in pa tients treated without plate fixation. No nonunions occurred in the patient s treated with plate fixation, There was significantly less disc space coll apse and kyphotic deformity with the plated fusions than with the nonplated fusions, in which a pseudarthrosis developed. The complication rates for p lated fusions are extremely low and do not differ from those for nonplated fusions.