Risk factors of cage nonunion after anterior cervical discectomy and fusion

Abstract

The aim of our study was to explore risk factors of cage nonunion after anterior cervical discectomy and fusion (ACDF). 295 patients underwent ACDF in our hospital between Jan. 2014 and Jan. 2017. Of them, 277 patients suffered cage union (union group, UG) after 6-month follow-up and 18 did not (nonunion group, NG). We collected possible factors including gender, history of smoking, alcohol, hypertension, heart disease, diabetes, body mass index, diagnose, and preoperative visual analog scale -neck, visual analog scale-arm, neck disability index (NDI) and Japanese Orthorpaedic Association, surgical duration, blood loss, fusion levels, superior fusion segment, angle of C2–C7, range of motion for C2–C7, C2–C7 sagittal vertical axis and T1 slope. We performed univariable and multivariable analysis to compare data in 2 groups. The rate of cage nonunion after ACDF was 6.1% (18 of 295) in our study. The outcome of univariable analysis showed that age (63.5 ± 10.1), angle of C2–C7 (18.0 ± 4.6), range of motion of C2–C7 (32.5 ± 7.7), C2–C7 sagittal vertical axis (17.9 ± 4.3) and T1 slope (22.1 ± 5.3) were higher in NG than these (59.4 ± 9.2, 16.2 ± 4.5, 30.2 ± 6.9,16.1 ± 4.0, 20.9 ± 4.9) in UG. Additionally, patients with osteoporosis had markedly higher rate of cage nonunion after ACDF than those without. What's more, the multivariable analysis implied the same results with univariable analysis. Many factors could predict cage nonunion after ACDF. Cervical sagittal parameters play an important role in cage nonunion after ACDF. We hope that we can provide some guidance for spine surgeon before performing ACDF.

Predictive nomogram of cage nonunion after anterior cervical discectomy and fusion: A retrospective study in a spine surgery center

“…[ 25 ] Bao et al discovered that the angle of C2–C7 and T1 slope was all risk factors for nonunion of cage following ACDF. [ 8 ] In our study, we found that the angle of C2 to C7 (OR = 1.53, P < .001) was a significant predictor of nonunion. While, there was no significant difference between nonunion and union group in C2–C7 ROM, T1 slope and C2–C7 SVA.…”

“…[ 19 ] However, Bao and Van found no statistical difference between 1-level and 2-level ACDF. [ 8 , 20 ] In our study, we found that the rate of nonunion in cases with 3-level ACDF was 1.32-fold compared with 1-level.…”

“…However, its risk factors are controversial. [ 8 , 12 , 13 ] There was little article regarding comprehensive risk factors, including demographic information, surgical details, sagittal parameters, and serum vitamin D level, for cage nonunion after ACDF. The aim of the study is to investigate the risk factors for cage nonunion in cervical spondylotic cases after ACDF and construct a nomogram based the database in a spine surgery center.…”

“…[4][5][6] Several studies showed that implant material, age, low bone mineral density, smoking status, low level of vitamin D and multilevel ACDF were risk factors for cage nonunion. [7][8][9] However, its risk factors are controversial (Table S1, Supplemental Digital Content 1, http://links.lww.com/MD/H389).…”

The Effect of Subsidence on Segmental and Global Lordosis at Long-term Follow-up After Anterior Cervical Discectomy and Fusion

“…Nonunion is a known complication of ACDF with a reported rate of about 5 percent. 28,29 A systematic review by Karikari et al 3 found no significant differences in fusion rates based on cage subsidence. Since subsidence causes a compounding effect in multilevel cervical fusions, it is possible that cage subsidence in multilevel fusions increases the risk of nonunion.…”