Comparative Study of Clinical and Radiological Outcomes of a Zero-Profile Device Concerning Reduced Postoperative Dysphagia after Single Level Anterior Cervical Discectomy and Fusion

OBJECTIVE: This study analyzed clinical and radiological outcomes of a zero-profile anchored spacer (Zero-P) and conventional cage-plate (CCP) for single level anterior cervical discectomy and fusion (ACDF) to compare the incidence and difference of postoperative dysphagia with both devices. METHODS: We retrospectively reviewed our experiences of single level ACDF with the CCP and Zero-P. From January 2011 to December 2013, 48 patients who had single level herniated intervertebral disc were operated on using ACDF, with CCP in 27 patients and Zero-P in 21 patients. Patients who received more than double-level ACDF or combined circumferential fusion were excluded. Age, operation time, estimated blood loss (EBL), pre-operative modified Japanese Orthopaedic Association (mJOA) scores, post-operative mJOA scores, achieved mJOA scores and recovery rate of mJOA scores were assessed. Prevertebral soft tissue thickness and postoperative dysphagia were analyzed on the day of surgery, and 2 weeks and 6 months postoperatively. RESULTS: The Zero-P group showed same or favorable clinical and radiological outcomes compared with the CCP group. Postoperative dysphagia was significantly low in the Zero-P group. CONCLUSIONS: Application of Zero-P may achieve favorable outcomes and reduce postoperative dysphagia in single level ACDF.