The Association of Cervical Spine Alignment with Neurologic Recovery in a Prospective Cohort of Patients with Surgical Myelopathy: Analysis of a Series of 124 Cases

Background Cervical spine sagittal malalignment has been demonstrated to correlate with the severity of disease in patients with cervical spondylotic myelopathy (CSM). The impact of spinal alignment on neurologic recovery has not been investigated thoroughly. The goal of this study was to evaluate the variable impact of preoperative sagittal alignment on neurologic recovery among surgical myelopathic patients. Methods An analysis of prospectively collected data was performed on surgical CSM patients treated at a tertiary neurosurgical center. Demographic data and preoperative and postoperative measures of neurologic disability (modified Japanese Orthopedic Association [mJOA] score, Nurick grade, Neck Disability Index) were analyzed for dependency on cervical spine alignment (kyphotic vs. lordotic) as well as preoperative disease severity and spinal cord magnetic resonance imaging. Results Thirty-four percent of 124 CSM patients had preoperative kyphosis. Surgical intervention was more frequently anterior or combined anterior/posterior among this group than those with preserved lordosis. Most patients exhibited postoperative neurologic improvement; however, the extent was dichotomous, with greater improvement among patients with preoperative lordosis (ΔmJOA 3.1) than with preoperative kyphosis (ΔmJOA 1.4, P = 0.02). More severe preoperative disease and quantitative magnetic resonance imaging T2 hyperintensity also predicted poorer recovery (α = 0.05). Lordotic patients exhibited similar improvement when approached anteriorly or posteriorly, whereas kyphotic patients exhibited greater improvement when approached by an anterior or combined approach. It is unclear whether restoring lordosis protects against adjacent segment disease. Conclusions The majority of patients with CSM showed postoperative neurologic improvement. Patients with preoperative lordotic alignment exhibited greater improvement than those with preoperative kyphotic alignment. Furthermore, the choice of surgical approach impacted neurologic recovery among kyphotic patients, with those patients who were approached anteriorly or with a combined approach faring better.