P129. Clinical outcomes following anterior cervical discectomy and fusion for patients with central versus foraminal stenosis

BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) is an effective surgical option for the treatment of cervical stenosis. However, the adequacy of decompression and stabilization for patients with central stenosis versus foraminal stenosis has been debated. Many advocate for the use or addition of a posterior cervical approach to the neural foramen to ensure adequacy of decompression. However, this may be associated with a number of adverse effects, including inadequacy of central or anterior decompression, when indicated, and persistent postoperative neck pain. PURPOSE The aim of this study was to assess the effectiveness of ACDF alone across a number of postoperative clinical outcome measures for patients with central stenosis, foraminal stenosis or both. STUDY DESIGN/SETTING Retrospective cohort analysis. PATIENT SAMPLE Analysis was conducted of patients who underwent ACDF for cervical radiculopathy or myelopathy between 2008 and 2015 by one of two senior spine surgeons at our institution. Patients were excluded from analysis if they were under 18 years of age, had a previous operation to the cervical spine, or did not meet a minimum of six months follow-up. OUTCOME MEASURES Preoperative magnetic resonance imaging (MRI) was assessed to determine the location of neural stenosis and compression. Stenosis that occurred medial to the facet or uncovertebral joint in the axial plane was identified as central, whereas stenosis that occurred at, or lateral to, the facet and uncovertebral joints was identified as foraminal. Sagittal measures on plain films were also measured and analyzed, including cervical lordosis, sagittal vertical axis, fusion and T1 angles. Patient reported outcome measures included visual analogue scale (VAS) neck, VAS-arm and neck disability index (NDI). Objective outcome measures included the incidence of adjacent segment disease (ASD), fusion, subsidence and reoperation rate. METHODS Anteroposterior (AP) and lateral cervical radiographs were obtained during the preoperative, immediate postoperative (2-week postoperative follow-up appointment), and final follow-up period along with patient reported outcomes. Bivariate and multivariate analyses were performed to account for baseline differences in patient factors. RESULTS In total, 381 patients met our inclusion criteria. Of these, 126 had central stenosis, 96 had foraminal stenosis, and 159 had both. Average length of follow-up was 28.2 (range 6-101) months. The central stenosis-only and foraminal stenosis-only cohorts had a significantly greater percentage of females compared to the cohort with both central and foraminal stenosis (56.35% and 54.74% versus 40.25%, respectively), with no additional baseline differences between groups. There were no significant differences in the amount of change in the sagittal plane from preoperative to postoperative between cohorts on multivariate analysis. Each cohort experienced considerable improvements in patient reported outcome measures, however, there were no significant differences in preoperative or postoperative VAS-neck, VAS-arm, or NDI scores between groups. Similarly, there were no significant differences in the incidence of ASD, fusion, subsidence, or reoperation rate between groups. CONCLUSIONS Our findings suggest that ACDF offers adequate decompression and stabilization for patients with cervical stenosis, regardless of the location of neural compression as central, foraminal or a combination of both. These data may help to better guide preoperative planning and consideration of surgical approach to the affected level(s). FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.