Part 2 book “Apley and Solomon’s system of orthopaedics and trauma” has contents: The neck, the management of major injuries, injuries of the ankle and foot, injuries of the knee and leg, injuries of the hip and femur, injuries of the pelvis, injuries of the spine, injuries of the spine, injuries of the wrist, and other contents. | 17 The neck Jorge Mineiro & Nuno Lança APPLIED ANATOMY ANATOMICAL CONSIDERATIONS OF THE CERVICAL SPINE The neck has a gentle curvature with an anterior convexity. The bony structure of the neck is the cervical spine with seven vertebrae, arranged in a lordotic configuration of 16 to 25 degrees. This physiologic lordosis is never quite reversed, even in flexion, unless under pathologic conditions. Important palpable landmarks of the neck are the hyoid bone, which lies at the level of C3, the thyroid cartilage, lying in front of C4, and the cricoid cartilage, at the level of C6 (Figure ). The seven cervical vertebrae are different in shape. The first two, the atlas (C1) and the axis (C2), are morphologically different from all the other five vertebrae (C3–C7) that have a similar morphology. The atlas arises from three ossification centres. Without a vertebral body or spinous process, C1 has thick anterior and posterior arches merging laterally into large masses through which it articulates with the occipital condyles above and the axial facet joints below. The axis originates from six ossification centres. The vertebral body has a characteristic superior peg, the dens, which articulates with the posterior surface of the anterior arch of the atlas. The dens can have a posterior angulation of up to 30 degrees. The transverse ligament of the atlas runs across the back of a narrowed waist of the odontoid process, stabilizing the joint, particularly in rotation. The ossification of the dens starts at 6 months of gestation, but fusion to the C2 vertebral body is only completed by the age of 5–6 years. However, ossification of the tip of the dens starts at 3–5 years of age and will only be completely fused at a later stage, during adolescence. The large spinous process of the axis allows for muscle insertion, namely the rectus capitis and the inferior oblique muscles. The subaxial cervical spine extends from C3 to C7. With a smaller vertebral body, the subaxial cervical .
