Cervical Spine Balance of Multilevel Total Disc Replacement, Hybrid Surgery, and Anterior Cervical Discectomy and Fusion With A Long-term Follow-up

Background To investigate the relationships between sagittal parameters and health-related quality of life (HRQOL) scores following anterior cervical hybrid decompression and fusion (ACHDF) of multilevel cervical spondylotic myelopathy (CSM) and to study the impact of the T1 slope (T1 s). Methods In total, 42 patients with complete radiographic measurements following ACHDF in the Spine Surgery Department of the First Affiliated Hospital of Fujian Medical University from August 2014 to January 2017 were retrospectively analysed. Radiographic measurements included C2–7 lordosis, T1 s, C2–7 sagittal vertical axis (SVA), cervical tilting and cranial tilting. The neck disability index (NDI) was used to evaluate the HRQOL. Spearman’s correlation coefficients were calculated between pairs of cervical sagittal parameters and NDI scores. Results Preoperative NDI scores were correlated with preoperative T1 s (r = 0.413); follow-up NDI scores were correlated with follow-up T1 s (r = 0.534). The regression analysis indicated that a preoperative T1 s value of 42.36° corresponded to a preoperative NDI score of 25 (r2 = 0.171, P < 0.001). A follow-up T1 s value of 48.61° corresponded to a follow-up NDI score of 25 (r2 = 0.421, P < 0.01). The differences in C2–7 SVA and cranial tilting before and after the operation were statistically significant (P < 0.05). Conclusion This study showed that the sagittal balance of the cervical vertebrae changed significantly after ACHDF, showing a forward trend. The sagittal parameters after ACHDF were related to clinical prognosis. An excessive T1 s can be considered a risk factor. The T1 s could provide a reference value to determine the correction of the sagittal balance of the cervical spine.

Study Design: Review. Objectives: Cervical spondylotic myelopathy (CSM) is a major cause of disability, particular in elderly patients. Awareness and understanding of CSM is imperative to facilitate early diagnosis and management. This review article addresses CSM with regard to its epidemiology, anatomical considerations, pathophysiology, clinical manifestations, imaging characteristics, treatment approaches and outcomes, and the cost-effectiveness of surgical options. Methods: The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. Results: The clinical presentation and natural history of CSM is variable, alternating between quiescent and insidious to stepwise decline or rapid neurological deterioration. For mild CSM, conservative options could be employed with careful observation. However, surgical intervention has shown to be superior for moderate to severe CSM. The success of operative or conservative management of CSM is multifactorial and high-quality studies are lacking. The optimal surgical approach is still under debate, and can vary depending on the number of levels involved, location of the pathology and baseline cervical sagittal alignment. Conclusions: Early recognition and treatment of CSM, before the onset of spinal cord damage, is essential for optimal outcomes. The goal of surgery is to decompress the cord with expansion of the spinal canal, while restoring cervical lordosis, and stabilizing when the risk of cervical kyphosis is high. Further high-quality randomized clinical studies with long-term follow up are still needed to further define the natural history and help predict the ideal surgical strategy.

Narrative review.