The Role of Sagittal Alignment in Surgery for Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) refers to any functional impairment in the spinal cord caused by degenerative changes in the cervical vertebral column. DCM is one of the most common causes of spinal cord dysfunction worldwide, especially among older adults. Compression on the spinal cord from both static and dynamic factors is believed to contribute to the usual natural history of DCM, which typically involves a progressive deterioration in neurological function mediated by demyelination and eventual necrosis of the gray and white matter. Cervical sagittal alignment is a critical component to both the natural history and the surgical management of DCM, as kyphotic deformities are independently associated with myelopathy and may force the spinal cord to drape over anterior degenerative structures in DCM, exacerbating cord compression and neurological decline. In this chapter, we review the pathogenesis of DCM, cervical spine alignment, and the surgical approaches to DCM with a focus on sagittal alignment.