To describe the main dimensions of the cervical vertebrae and spinal canal in two groups with juvenile idiopathic arthritis (JIA) and a non-inflammatory control group.

There were altogether 158 female patients in three different groups included in the study: a group with severe, complicated JIA (sJIA), a population based JIA group (pJIA), and fibromyalgia patients as a non-inflammatory control group (pFM). The patients’ clinical records and cervical spine radiographs taken in adult age (>17 years) were evaluated.

The patients with sJIA had the mean area of the 3rd–6th cervical vertebrae bodies and the average width and height of the 3rd–6th cervical vertebrae bodies significantly smaller than the patients in the pJIA and pFM groups. The mean value of the maximal difference between the successive vertebral body areas of each individual was significantly larger in the sJIA group than the other groups (p=0.047; the body height adjusted). There were no significant differences in the mean diameter of the sagittal spinal canal between study groups.

Inflammatory changes of the cervical spine are common, and growth disturbances of cervical vertebrae in patients with JIA have been described previously. We found that patients with severe complicated JIA have a smaller cervical vertebral body size in general. They also have more differences in the sizes of their own vertebrae, representing growth disturbances of individual vertebral bodies. This is probably caused by the inflammatory disease and/or its more aggressive pharmacotherapy. The spinal canal diameter was only slightly smaller in the sJIA group. Thus the disturbed growth of the vertebral body in sJIA does not, in general, increase the risk of spinal canal compression.