Success of junctional anterior cervical discectomy and fusion.

Abstract Background context Junctional breakdown has long been a consideration for surgeons when performing an arthrodesis in the cervical spine. Numerous authors have reported symptomatic junctional disease after fusion with varying degrees of reoperation. To our knowledge, there are no large series recording the fusion rate using instrumentation as an adjuvant to bone grafting. Purpose To determine the fusion rate when arthrodesis is performed in the setting of junctional stenosis using iliac crest autograft and instrumentation. Study design/setting This is a retrospective review performed on patients at the senior author's institution. Patient sample The patient population consisted of a consecutive series of patients undergoing an elective anterior-only cervical arthrodesis for junctional stenosis. Outcome measures The primary outcome is a physiologic measure from dynamic radiographs. Fusion was assessed by the absence of motion and radiolucent lines at the bone graft interface. Methods During the study period, a total of 56 consecutive patients underwent anterior treatment for junctional cervical stenosis. Forty-nine of these patients were treated with an anterior discectomy and instrumented arthrodesis using iliac crest autograft, and seven underwent a corpectomy. We retrospectively reviewed the patients' charts and radiographs to determine the fusion rate. Results A solid fusion was obtained in 81.6% of patients in the study group. In patients undergoing a single-level arthrodesis adjacent to a one-level fusion, the fusion rate was 95.2%. The fusion rate significantly dropped in patients with longer preexisting fusion segments. In patients with a two- or three-level fusions preoperatively, the union rate was 81.3% and 57.1%, respectively. Conclusions Anterior cervical discectomy and arthrodesis yields a high fusion rate for cervical stenosis adjacent to a single-level fusion. A multilevel preexisting fusion segment leads to a significant decline in successfully achieving a solid adjacent fusion despite using iliac crest autograft and instrumentation.