In the AP cervical spine radiograph, which joints must be included to assess alignment at the upper cervical region?

In the AP cervical spine radiograph, which joints must be included to assess alignment at the upper cervical region?

• A. Atlantoaxial joints
• B. Zygapophyseal joints
• C. Intervertebral discs
• D. Facet joints

Answer: (A)

Upper cervical alignment is defined by how the atlas sits over the axis at the atlantoaxial joints. These joints—and the relationship between the atlas (C1) and the axis (C2)—are where any misalignment would be most evident, because that is the area that directly controls the upper cervical stability and rotation. When you include the C1–C2 region on an AP cervical radiograph, you can check that the atlas sits properly over the dens of C2 and that there’s no abnormal anterior or posterior displacement. Other structures, like the zygapophyseal joints or the intervertebral discs, aren’t the primary references for assessing upper cervical alignment on this view, and discs aren’t clearly visible on plain radiographs. So visualizing the atlantoaxial joints is essential.

Upper cervical alignment is defined by how the atlas sits over the axis at the atlantoaxial joints. These joints—and the relationship between the atlas (C1) and the axis (C2)—are where any misalignment would be most evident, because that is the area that directly controls the upper cervical stability and rotation. When you include the C1–C2 region on an AP cervical radiograph, you can check that the atlas sits properly over the dens of C2 and that there’s no abnormal anterior or posterior displacement. Other structures, like the zygapophyseal joints or the intervertebral discs, aren’t the primary references for assessing upper cervical alignment on this view, and discs aren’t clearly visible on plain radiographs. So visualizing the atlantoaxial joints is essential.