Articulation of the Vertebral Column with the Pelvis

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Anatomy > Gray's Anatomy of the Human Body > III. Syndesmology > 5h. Articulation of the Vertebral Column with the Pelvis

Henry Gray (1821–1865). Anatomy of the Human Body. 1918.

Articulation of the Vertebral Column with the Pelvis

The connection between the vertebral column and the pelvis involves a combination of joints and ligaments, particularly where the fifth lumbar vertebra (L5) interfaces with the sacrum (S1). These structures form a crucial transitional zone between the mobile lumbar spine and the rigid sacroiliac joints of the pelvis.

The articulation includes:

• The inferior continuation of the anterior longitudinal ligament and posterior longitudinal ligament
• The intervertebral disc between the L5 and S1 vertebral bodies, forming an amphiarthrosis
• The ligamenta flava, uniting the adjacent laminae of L5 and S1
• Articular capsules surrounding the zygapophyseal joints (facet joints), forming paired arthrodial joints
• The interspinous ligament and supraspinous ligament connecting adjacent spinous processes

Additionally, a special accessory ligament connects the vertebral column directly to the ilium of the pelvis: the iliolumbar ligament.

Iliolumbar Ligament (ligamentum iliolumbale)

FIG. 319 – The iliolumbar ligament, connecting L5 to the ilium and sacrum. (Picture from the classic Gray's Anatomy)

The iliolumbar ligament is a strong fibrous band that connects the transverse process of the L5 vertebra to the iliac crest and sacrum.

Attachments

• Superiorly: To the anterior and inferior portion of the transverse process of the fifth lumbar vertebra
• Inferiorly:

One band attaches to the iliac crest, just anterior to the sacroiliac joint Another band blends with the anterior sacroiliac ligament and attaches to the lateral part of the sacrum

The ligament spreads out as it passes laterally, forming a fan-shaped structure that reinforces the lumbosacral junction.

Relations

• Anteriorly: Related to the psoas major muscle
• Posteriorly: In contact with the erector spinae muscles and other musculature in the vertebral groove
• Superiorly: Continuous with the thoracolumbar fascia (also referred to as the lumbodorsal fascia)
• Inferiorly: Near the superior margin of the iliacus and adjacent structures of the pelvis

Function

The iliolumbar ligament serves as a stabilizer of the lumbosacral junction. It:

• Resists excessive movement at the L5–S1 joint
• Prevents anterior translation of the L5 vertebra on the sacrum
• Contributes to the integrity of the pelvic girdle during load transfer between the spine and lower limbs

Damage or laxity of this ligament has been implicated in certain types of low back pain and lumbosacral instability.

See Also

• Lumbosacral joint
• Sacroiliac joint
• Intervertebral disc
• Lumbar vertebrae
• Pelvic girdle
• Spinal ligaments
• Psoas major
• Thoracolumbar fascia

Gray's Anatomy

• Gray's Anatomy Contents
• Gray's Anatomy Subject Index
• About Classic Gray's Anatomy
• Glossary of anatomy terms

Anatomy atlases (external)

[1] - Anatomy Atlases

Adapted from the Classic Grays Anatomy of the Human Body 1918 edition (public domain)