Soft disc herniation of the cervical spine.

The definition of soft disc hernia of the cervical spine is not always clear, so we have studied 34 cases where soft disc material was extruded or had migrated outside the intervertebral space. There were 22 cases of the paracentral-central type and 12 cases of the posterolateral type. The diagnosis was made by discography using anteroposterior, lateral and both oblique radiographs. All the patients complained of pain or discomfort in the neck or the interscapular region which was increased by the neck compression test and reproduced during discography. Severe pain in the area was present in all the cases of the posterolateral type and in about half of the paracentral-central type. Cord signs, such as increased reflexes in the lower limbs, were found in 15 cases of the paracentral-central type and in 5 cases of the posterolateral type. These signs correlated with the width of the spinal canal and the amount of prolapsed disc material. Discography and reproduction of pain were most useful for the diagnosis of this type of hernia. It has now become possible to differentiate the paracentral type from the central type by performing computerised tomography scanning after discography. We treated 12 cases conservatively and 22 cases surgically, and obtained good results in both groups.