Front Matter

Chapter 17 Diagnosis of and Treatment Options for Disorders of the Spine 427

of each vertebral body. This ligamentous con­
tinuation of the nuchal ligament is called the
supraspinous ligament. The thoracic spines
are attached to each other by way of the inter­
spinous ligament. The interspinous ligaments
allow the force of the weight of the head to dis­
sipate through the dog’s body but still main­
tain a level of flexibility. These nonmuscular
components form a very efficient system
where muscular energy is conserved. The cer­
vical vertebrae are large and proportional to
the weight of the head. The forces required to
suspend the head are complemented by
absorption of compressive forces placed upon
the cervical intervertebral discs.
The first and second cervical vertebrae have
rather unique conformations that serve two
significant purposes. The nuchal ligament is
attached to the second cervical vertebra’s large

and wide dorsal spine so that the forces required

to keep the head in various positions are dis­

sipated over a large surface. Fan‐shaped mus­

cles, predominately the splenius, attach to the

nuchal crest of the caudal skull and, like the

nuchal ligament, arise from the cranial thoracic

vertebrae’s dorsal spines. This conformation

also acts as a cantilever allowing the head to

rotate and be supported by the compressive

forces placed upon the atlanto‐occipital joint

(Figure 17.3).

The joints and articular facets of the cervical

vertebrae C3–C7 are quite large and play a sig­

nificant role in controlling fine movement of the

head and neck in three planes. Their role in

support of the neck is unknown but they may

play a minor role, as their removal does not sig­

nificantly affect the biomechanics of the neck

(Crisco et al., 1990).

(C)

(B)

(A)

Figure 17.3 (A) Base of the skull showing the large occipital condyles that attach the skull to the cervical spine and the
broad nuchal crest that is an important muscular attachment. (B) The first (atlas) and second (axis) cervical vertebrae
disconnected to demonstrate how C2 fits into and joins C1. (C) An end‐on view of the most rostral cervical spine
demonstrating the C1–C2 articulation and the large atlanto‐occipital joint.