Injections of the cervical spine are frequently used for pain management in chronic pain medicine. The concentration of bony structures and nerves in the cervical spine, each of which can be a cause of pain, as well as vessels, requires an intimate knowledge of the anatomy. The relevant procedures in the cervical spine include facet joint and medial branch blocks, selective nerve root injection, third occipital nerve block, epidural steroid injection, and stellate ganglion block. In this chapter we discuss the anatomy relevant for these procedures.
BASIC CERVICAL SPINE ANATOMY
The cervical spine (Figs. 6–1 to 6–3) is a column of seven vertebrae supporting the skull and neck structures. The atlanto-occipital and atlantoaxial joints are unique. The former is an ellipsoid joint, and the atlantoaxial joint is a rotatory joint. The atlantoaxial joint is bordered by the C2 dorsal root ganglion and vertebral artery. The cervical vertebrae are identified by the presence of the foramen transversarium (transverse foramen) for the vertebral artery.
Cervical spine – lateral view.
Cervical spine – anterior view. VB, vertebral body.
Cervical spine – posterior view.
Typical Cervical Vertebra (C3 to C6)
The third to sixth cervical vertebra are considered typical cervical vertebra (Fig. 6–4), whereas the first, second, and seventh cervical vertebra are atypical with certain unique features (Figs. 6–5 and 6–6). The general characteristics of a typical cervical vertebra are described next. The upper five cervical vertebrae (C3 to C7) each have a concave superior surface and are convex on the inferior surface. They articulate with the adjacent vertebrae via uncovertebral joints (joints of Luschka). These are thought to be due to degenerative tears in the annulus of the intervertebral disc, leading to creation of the uncovertebral joint. Uncovertebral joint osteophytes can contribute to narrowing of the exit foramina. The spinal canal (vertebral canal) in the cervical spine is larger than the size of the body. It is also triangular shaped because the pedicles are directed backwards and laterally (Fig. 6–4). The superior and inferior vertebral notches are usually equal sized. The laminae are relatively long and narrow and thinner above than below. The superior and inferior articular processes form the articular pillars and project laterally at the junction of the pedicle and transverse process. The superior articular facets are directed backwards and upwards, whereas the inferior articular facets are directed forwards and downwards (Fig. 6–1). The transverse process of each vertebra is pierced by the foramen transversarium (Fig. 6–4) to allow for the passage of the vertebral arteries ...