The symptomatic incompetent cervical intervertebral disc.

A series of 16 patients with symptoms such as pain in the neck, occiput, shoulder and arm; numbness in the hands; and/or difficulty in walking, is described. Neurological examination of the upper extremities disclosed signs of nerve roots dysfunction in 5 patients and long tract signs in 12, whereas examination of the lower extremities disclosed long tract signs in every patient. Positive contrast cervical myelograms suggested mild posterior bulging of one or two intervertebral discs in every patient, but computed tomographic myelograms invariably demonstrated a coincident narrow cervical spinal canal, thus revealing the true compressive potential of the aforementioned mild disc protrusion on the spinal cord. All patients underwent anterior cervical microdiscectomy of the offending disc or discs, which were found to be degenerated. No case of frank rupture of the anulus was identified. Response to treatment was graded as excellent in 12 patients, who had complete relief of symptoms, and good in 4 patients, who had mild residual complaints. This study suggests that incompetence (bulging) of a cervical intervertebral disc may acquire important clinical significance in the presence of a narrow spinal canal by compressing the spinal cord and the corresponding nerve roots. Surgical removal of the diseased disc may result in restoration of neurological function.