Cervical alignment and clinical outcome of anterior decompression with fusion vs. posterior decompression with fixation in kyphotic cervical spondylotic myelopathy

BACKGROUND CONTEXT: Cervical kyphosis is a common but potentially debilitating and challenging condition. There is controversy on the optimal surgical strategy for the treatment of kyphotic cervical spondylotic myelopathy (KCSM) using either anterior approach or posterior approach. INTRODUCTION: The purpose of this study was to investigate the surgical efficacy of anterior decompression with fusion (ADF) vs. posterior decompression with fixation (PDF) for the treatment of KCSM, and to further analyze the changes of cervical spinal alignment parameters and axial symptoms (AS) severity after kyphotic correction. MATERIALS AND METHODS: We retrospectively reviewed 117 patients with KCSM who had undergone ADF (58 patients) and PDF (59 patients) between January 2016 and December 2020. Cervical spinal alignment parameters, including curvature index (CI) and C2-7 Cobb angle, were measured on the PreOP and PostOP lateral radiographs. Recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. AS severity was quantified by Neck Disability Index (NDI). A P-value less than 0.05 was considered to be significant. RESULTS: The patient mean age, gender, presenting symptoms and follow-up time were similar between the two groups (P > 0.05). However, there were statistically significant differences (P < 0.001) between the two groups regarding the operation levels, operating time and intraoperative blood loss. Analysis of PostOP follow-up data showed significant differences (P < 0.001) in CI, correction of CI, C2-7 Cobb angle, and NDI between the two groups, whereas no significant differences in JOA score (P = 0.16) and recovery rate (P = 0.14). There were significant differences (P < 0.001) in CI, C2-7 Cobb angle, JOA score, and NDI between PreOP and PostOP follow-up in each group. Correction of CI showed positive correlation with recovery of NDI in Group ADF (r = 0.51, P < 0.001), and in Group PDF (r = 0.45, P < 0.001). CONCLUSION: Satisfied neurological improvement was obtained by ADF and PDF for patients with KCSM. Cervical kyphotic correction caused significant improvement of AS, and was more favorable with ADF than with PDF. Surgeons should pay full consideration of the merits and shortcomings of each approach when deciding on a surgical plan.