The ligaments are responsible for the stability and elasticity of the vertebral column. They run between the vertebral bodies and the vertebral arches of adjacent vertebrae.
Anterior longitudinal ligament
The anterior longitudinal ligament runs from the second cervical vertebra to the sacrum along the front of the vertebral bodies. It is adherent to the anterior surfaces of the bodies and intervertebral discs.
Posterior longitudinal ligament
The posterior longitudinal ligament runs along the posterior surfaces of the bodies and discs. It is adherent to the posterior surface of the bodies and intervertebral discs. It narrows as it passes over the bodies, and widens over the discs.
Ligamentum flavum (or ‘the yellow ligament’)
The ligamentum flavum is a thick, strong, elastic structure that runs the full length of the spine. At each vertebral level, the ligamentum flavum connects the laminae of adjacent vertebrae, extending between the lower inner surface of the laminae above to the upper outer surface of the laminae below. The ligamentum flavum thickens as it descends the spine, and is thickest in the lumbar region. A loss of resistance is felt when a Tuohy needle breaches the ligamentum flavum, and this is used to identify the epidural spa
The interspinous ligament is a thin membranous band that connects adjacent spinous processes It lies in a sagittal plane and extends from the supraspinous ligament posteriorly to the ligamentum flavum anteriorly.
The supraspinous ligament is a band of longitudinal fibres connecting the tips of the spinous processes. It runs from C7 to the sacrum. It is continuous with the interspinous ligament anteriorly and the ligamentum nuchae superiorly.
The intertransverse ligaments link the transverse processes of adjacent vertebrae
the anterior surface markings of the body and their relation to the levels of the vertebrae. The larynx is at the level of C4-C6. The thyroid cartilage of the larynx (Adam’s apple) is at the level of C4. Palpating it, then moving lateral to the carotid artery pulse, allows a needle to be passed onto the lamina of C4 in order to perform a stellate ganglion block. The xiphisternum is at the level of T10 and the umbilicus is at the level of the intervertebral disc between L3 and L4.
From top to bottom, the first spinous process that can be palpated through the skin of the back is that of C7
The spinous process of T1 is the most prominent
When the arms are by the sides, the root of the spine of the scapula is level with the tip of the spinous process of T3
The inferior angle of the scapula is level with that of T7
The tops of the iliac crests are level with the body and spinous process of L4 . However, in the elderly, vertebral body fractures and ‘slumping’ of the spine into the pelvis can make this landmark inaccurate. Likewise, in the morbidly obese, adipose tissue on top of the hips can make the iliac crests appear more cephalad.
Two skin dimples lie at the top of the buttocks at the level of S2
These dimples overlie the posterior superior iliac spines which form an equilateral triangle with the sacral hiatus.