Surgical management of cervical degenerative disease: the evidence related to indications, impact, and outcome.

In this special edition of Journal of Neurosurgery: Spine, a series of systematic reviews sponsored by the Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons/Congress of Neurological Surgeons is presented. This collection of comprehensive reviews summarizes the medical evidence related to the surgical management of cervical degenerative disc disease. Several of the key conclusions are discussed in this introduction to the issue: There is Class II evidence to suggest that the clinical condition remains stable when observed over a 3-year period in patients with mild-to-moderate cervical spondylotic myelopathy (CSM) and age younger than 75 years. There is consistent Class III evidence that the duration of symptoms, and possibly advancing age, negatively affect outcome in patients with CSM. There is Class II evidence that somatosensory evoked potentials have prognostic value in patients with CSM. There is Class I evidence to show that electromyographic abnormalities (as well as the presence of radiculopathy) are predictive of the development of myelopathy in minimally symptomatic patients with cervical stenosis and spinal cord compression. The presence of a low signal on T1-weighted images, high signal on T2-weighted images, and the presence of cord atrophy on preoperative MR images are indicators of a poor outcome in CSM. There is Class III evidence to show that anterior or posterior surgical approaches that effectively decompress the cervical canal promote short-term improvements in outcome. However, there appears to be a risk of late kyphosis in patients who undergo laminectomy or anterior cervical discectomy alone compared with patients in whom decompression is combined with fusion. The use of BMP-2 is discouraged for anterior cervical spine surgery based on evidence suggesting that the risks outweigh any potential benefits. Finally, in patients with symptomatic cervical radiculopathy, arthroplasty achieves outcomes that are equivalent to anterior cervical decompression and fusion, although evidence for superiority is lacking. Further prospective longitudinal data are required to better define the role and timing of surgical intervention in CSM and to determine the appropriate use of cervical arthroplasty in the management of symptomatic cervical degenerative disc disease.