370 Is There an Optimal Surgical Approach in Degenerative Cervical Myelopathy?: An Individual Participant Data Meta-Analysis

INTRODUCTION: Contradictions exist about impact of anterior vs. posterior surgical approach on outcomes of degenerative cervical myelopathy (DCM). METHODS: Individual patient data of subjects who underwent surgery for DCM was identified from a pooled dataset of the AO Spine CSM-North America, CSM-International, and CSM-Protect clinical studies. Primary outcomes were changes in short form 36 Physical Component Summary score (SF36-PCS) and mJOA score at 12 months. Secondary outcomes were change in total Neck Disability Index (NDI) score and SF36 Mental Component Summary score (SF36-MCS). Two comparison cohorts were created: i) anterior surgery and ii) posterior surgery. One-stage mixed-effects meta-analysis with study and treatment exposure as random effects was performed and reported with mean differences and 95% confidence intervals. A subgroup analysis planned a priori in mild DCM patients (mJOA 15-17) was performed. RESULTS: A total of 979 patients met eligibility criteria. Patients who had anterior decompressive surgery experienced greater improvements at 1yr of follow-up than those who underwent posterior decompressive surgery in SF36-PCS score (adjusted MD 1.57 [95% CI 0.11 to 3.03], p = 0.0348) and NDI score (adjusted MD 3.32 [95% CI 0.58 to 6.05], p = 0.0172). A greater proportion of patients that underwent anterior surgery achieved clinically important recovery of their NDI (OR 1.49 [95% CI 1.15 to 1.93], p = 0.002; aOR 1.46 [95% CI 1.08 to 1.96], p = 0.013) and SF36-PCS scores at 1yr (OR 1.45 [95% CI 1.12 to 1.88], p = 0.004, aOR 1.34 [95% CI 1.00 to 1.80], p = 0.052). In patients with mild DCM (n = 186), patients who underwent anterior decompressive surgery experienced greater improvements in SF36-PCS score, mJOA score, and Neck Disability Index score than posterior surgical patients. CONCLUSIONS: Anterior surgical decompression for DCM is associated with greater improvements in 1yr patient-reported outcomes than posterior surgical decompression.