Anterior Cervical Discectomy and Fusion versus Posterior Decompression in Patients with Cervical Degenerative Myelopathy: A Systematic Review and Meta-analysis

Introduction: The optimal surgical approach for multi-level degenerative cervical myelopathy (DCM) remains unknown. This study seeks to compare anterior cervical discectomy and fusion (ACDF) versus posterior decompression (PD) in patients with symptomatic DCM with ≥ 2 level involvement and without ossification of posterior longitudinal ligament.

Methods: Medline and PubMed were searched. The primary outcomes were neck disability index (NDI), short from-36 physical component summary (SF-36 PCS), modified Japanese Orthopaedic Association (mJOA) scale, visual analog scale (VAS), and EuroQol5Dimensions (EQ-5D). Secondary outcomes were operative bleeding, duration of operation (minute), length of hospital stay (LOS) (day), complications, mortality, readmission, and reoperation.

Results: 19 studies yielding 8340 patients were included, of which 4118 (49.3%) and 4222 (50.6%) underwent ACDF and PD, respectively. The mean of spinal level involvement was comparable between the groups (3.1 vs. 3.5, p=0.15). After 1-year follow-up, mean difference (MD) of NDI (MD=-1.67[-3.51, 0.18], p=0.08), SF-36 PCS (MD=2.48[-0.59, 5.55], p=0.11), and VAS (MD=-0.32[-0.97, 0.34], p=0.35) were similar between the groups. While MD of mJOA (MD=0.71[0.27, 1.16], p=0.002) and EQ-5D (MD=0.04[0.01, 0.08], p=0.02) were greater in the ACDF group, the differences were not clinically significant given the meaningful clinically important difference [MCID] of 2 and 0.05, respectively. In the ACDF group, MDs of operative bleeding (MD=-102.77ml [-169.23, -36.30], p=0.002) and LOS (MD=-1.42[-2.01, -0.82], p< 0.00004) were lower; odds ratio (OR) of dysphagia (OR=11.10[5.43, 22.67], p< 0.0001) was higher, and ORs of wound infection (OR=0.43[0.24, 0.78], p=0.006) and C5 palsy (OR=0.32[0.15, 0.70], p=0.004) were lower. The other outcomes were not significantly different between the groups. Overall evidence per GRADE approach was moderate.

Conclusion : The two approaches are similar in functional outcomes. The ACDF is beneficial in terms of lower bleeding, shorter LOS, lower odds of wound infection, and C5 palsy, while it carries higher odds of dysphagia. We recommend individualized treatment decision-making.