Anterior Cervical Discectomy and Fusion: Comparison of Fusion, Dysphagia, and Complication Rates Between Recombinant Human Bone Morphogenetic Protein-2 and Beta-Tricalcium Phosphate.

INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) is one of the most common spinal procedures performed. A direct comparison of the fusion and complication rates between recombinant human bone morphogenetic protein-2 (rhBMP2) and beta-tricalcium phosphate (bTCP) has not been reported. METHODS: A retrospective study of 191 consecutive patients who underwent ACDF with polyetheretherketone plastic fusion spacers during a 2-year period with either rhBMP2 (n = 84, 46%) or bTCP (n = 107, 56%) was performed. Patients underwent 1- (35%), 2- (41%), 3- (20%), and 4- (4%) level operations. The primary outcome measure was mature arthrodesis, with secondary measures including clinical outcomes and complication occurrence. Fusion was graded on plain lateral radiographs, with median length of follow-up of 12 months. RESULTS: Rates of cervical fusion were significantly greater for patients treated with rhBMP2 than bTCP at both 6 months (70% vs. 26%, P = 0.000) and 12 months (99% vs. 85%, P = 0.000). Postoperative dysphagia was reported in 35 patients (18%), with no difference in dysphagia incidence between rhBMP2 and bTCP (20% vs. 17%, P = 0.5); however, dysphagia was more severe in the rhBMP2 group, with greater rates of readmission and steroid use (both P < 0.05). A multivariable sensitivity analyses to control for patient characteristics and number of spinal fusion levels showed no differences in dysphagia rate between rhBMP2 and bTCP. CONCLUSIONS: In our cohort, the rate of mature arthrodesis after ACDF was greater with rhBMP2 compared with bTCP with no increased incidence of postoperative dysphagia; however, dysphagia severity was greater in the rhBMP2 cohort.