122 Prospective, Randomized, Blinded Clinical Trial Comparing PEEK and Allograft Spacers in Patients Undergoing ACDF Surgeries

INTRODUCTION: The biomechanical qualities as well as osteoconductive, osteogenic, and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. METHODS: Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. Radiographic and clinical outcomes were assessed at 3, 6, 12 and 24 months with an additional postoperative radiographic assessment. RESULTS: A total of 120 patients were enrolled and randomized. Comparing clinical outcomes, no differences in arm or neck pain scores were noted, however, there was a statistically significant (<0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency towards lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (p=0.72) in the PEEK and allograft groups, respectively. At the 24-month follow-up, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24-month follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. CONCLUSIONS: Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK vs. allograft-assisted ACDF surgeries.