Axial symptoms and cervical alignments after cervical anterior spinal fusion for patients with cervical myelopathy.

This retrospective clinical study was designed to examine the relation between cervical alignment and axial symptoms developing after cervical anterior spinal fusion. Sixty patients with myelopathy treated with cervical anterior spinal fusion were reviewed. For radiographic evaluation, lordosis, enlargement of the fused segments and neural foramen, radiographic union, and degeneration of adjacent segment were reviewed before or after surgery or both. Twenty-three patients had axial symptoms. Only local kyphosis and narrowing of the neural foramen at the fused segment were recognized more often in patients with axial symptoms than in those without such symptoms. No less than 2 mm and < or = 5 mm in enlargement of the anterior disc space immediately after surgery resulted in maintenance of cervical lordosis. These findings suggest that > or = 2 mm and < or = 5 mm in enlargement of anterior vertebral body height during operation results in prevention of axial symptoms.