Changes in the cervical spine of children with juvenile idiopathic arthritis evaluated with lateral cephalometric radiographs: a case control study

Abstract

Objective: To evaluate whether plain lateral cephalometric radiographs in the neutral position could be used as a diagnostic tool to investigate changes in the cervical spine related to juvenile idiopathic arthritis (JIA).

Materials and methods: Lateral cephalometric radiographs of 82 subjects, 21 males and 61 females (8-25 years old), affected with JIA were revised and compared with 82 healthy control subjects matched in age and gender. Changes inspected in the cervical spine were erosions of the dens and fusion of the apophyseal joints. Anterior atlantoaxial subluxation of the first vertebra in relation to the second was examined by measuring the anterior atlanto-dens interval (aADI). Atlantoaxial impaction (AAI) was studied by using the Sakaguchi-Kauppi method.

Results: In the JIA sample, erosion was seen in 14.7%, (12 patients), of the patients and apophyseal joint ankylosis (fusion) in 18.3%, (15 patients). Three children and one adult had aADI more than 4.5 or 3 mm, respectively, which is considered to be abnormally increased, and AAI was noted in 13.0% of the subjects. In total, 35%, (29 children), of the children with JIA showed one or several radiographically visible changes as described earlier. Two of the control subjects showed ankylosis of the apophyseal joints, and one had aADI of 4 mm. Compared with the controls, significantly more changes were found in the JIA group.

Conclusion: It can be concluded that arthritic changes in the cervical spine can be detected at a young age on plain lateral cephalometric radiographs and should be evaluated when available.

Figure 1

Duration of the disease of patients with JIA.

Figure 2

Age at onset.

Figure 3

Apophyseal joint ankylosis or fusion between C2, C3, C4, and C5.

Figure 4

aAAS: aADI ≥4 mm (black arrow).

Figure 5

AAI grade I (see Figure 6).

Figure 6

(a) Grade I: Normal. Inferior margin of C1 arch under the level of the C2 facet (top of C2 sclerotic ring). (b) Grade II: Inferior margin of the C1 arch reaches the level of the C2 facet. (c) Grade III: Midpoint of the C1 arch reaches the level of the C2 facet. (d) Grade IV: Superior margin of the C1 arch reaches the level of the C2 facet. AAI (ie, vertical subluxation or cranial settling) is diagnosed by the S-K method, which evaluates the position of the atlas (C1) in relation to the axis (C2). This study is age independent and therefore usable in children. In a lateral radiograph, the atlantoaxial facet joints are projected onto each other and form an easily visible curve on the side of the vertebral body of the axis. The most cranial tip of this curve is formed by the most cranial bony parts of the superior facets of the axis. If the cartilage layers of the facet joints are healthy, the tips of the bony facets of the axis are situated under the line that can be drawn form the lowest part of the anterior atlas arch to the lowest part of the posterior atlas arch (the lower atlas arch line). This is the normal situation, which is called grade I. (Figure used courtesy of Dr Kauppi.27)