Thoracolumbar Spine Dr. Zeenat Zaidi & Dr. Saeed Vohra Dr. Zeenat Zaidi & Dr. Saeed Vohra Dr. Zeenat & Dr. Vohra 1

Thoracolumbar Spine

Dr. Zeenat Zaidi &

Dr. Saeed Vohra

Dr. Zeenat & Dr. Vohra1

OBJECTIVESOBJECTIVESAt the end of the lecture, students should be able to:At the end of the lecture, students should be able to: Distinguish the thoracic and lumbar vertebrae from

each other and from vertebrae of the cervical region Describe the characteristic features of a thoracic and

a lumbar vertebra. Compare the movements occurring in thoracic and

lumbar regions. Describe the joints between the vertebral bodies and

the vertebral arches. List and identify the ligaments of the intervertebral

joints.

• The thoracolumbar spine is a combination The thoracolumbar spine is a combination of vertebrae, intervertebral joints, of vertebrae, intervertebral joints, ligaments/tendons, muscles, nerves and ligaments/tendons, muscles, nerves and vascular supply.vascular supply.

• The The thoracic region thoracic region consists of consists of 1212 vertebrae. Due to its articulations with rib vertebrae. Due to its articulations with rib cage, the thoracic spine is more rigid than cage, the thoracic spine is more rigid than the cervical and lumbar regions.the cervical and lumbar regions.

• The The lumbar spine lumbar spine is made up of is made up of 55 vertebrae. It is designed to be strong, vertebrae. It is designed to be strong, protecting the spinal cord and spinal nerve protecting the spinal cord and spinal nerve roots. At the same time, it is highly flexible, roots. At the same time, it is highly flexible, providing mobility in many different planes providing mobility in many different planes including flexion, extension, lateral flexion, including flexion, extension, lateral flexion, and rotation.and rotation.

3

Note the curvatures in thoracic (primary, concave anteriorly) and lumbar Note the curvatures in thoracic (primary, concave anteriorly) and lumbar (secondary, convex anteriorly) spine(secondary, convex anteriorly) spine

Dr. Zeenat & Dr. Vohra

THORACOLUMBAR SPINETHORACOLUMBAR SPINE

THORACIC VERTEBRAETHORACIC VERTEBRAE

Most Most thoracic vertebraethoracic vertebrae are typical, have bodies, vertebral arches, are typical, have bodies, vertebral arches, and seven processes for muscular and articular connections. There and seven processes for muscular and articular connections. There

are regional variations from Tl to T12are regional variations from Tl to T12


Superior view Lateral view

The The bodybody is medium is medium size and heart shaped.size and heart shaped.

The The vertebral vertebral foramenforamen is small is small and circularand circular

The The spinesspines are long are long and inclined downward.and inclined downward.

Costal facets Costal facets are are present on the present on the sides sides of the bodies of the bodies for for articulation with the articulation with the heads of the ribs.heads of the ribs.

Costal facets Costal facets are present are present on the on the transverse transverse processes processes for articulation for articulation with the tubercles of the with the tubercles of the ribs (T11 and 12 have no ribs (T11 and 12 have no facets on the transverse facets on the transverse processes).processes).

The The superior articular processes superior articular processes bear facets that face backward and laterally, bear facets that face backward and laterally, whereas the facets on the whereas the facets on the inferior articular processes inferior articular processes face forward and face forward and medially. The inferior articular processes of the 12th vertebra face laterally, as do medially. The inferior articular processes of the 12th vertebra face laterally, as do those of the lumbar vertebrae.those of the lumbar vertebrae.

CHARACTERISTICS OF A TYPICAL THORACIC VERTEBRACHARACTERISTICS OF A TYPICAL THORACIC VERTEBRA


CHARACTERISTICS OF A TYPICAL LUMBAR VERTEBRACHARACTERISTICS OF A TYPICAL LUMBAR VERTEBRA

The body is large and kidney shaped.

The The pediclespedicles are are strong and directed strong and directed backward.backward.

The The laminaelaminae are thick are thick.

The The vertebral vertebral foramina foramina are are triangular.triangular.

The The transverse transverse processes processes are long are long and slender.and slender.

The The spinous processes spinous processes are short, flat, are short, flat, & quadrangular and project backward.& quadrangular and project backward.

The articular surfaces of the The articular surfaces of the superior articular processes superior articular processes face medially, and face medially, and those of the those of the inferior articular processes inferior articular processes face laterally.face laterally.



THORACIC VERTEBRATHORACIC VERTEBRALUMBAR VERTEBRALUMBAR VERTEBRA

Lateral viewLateral view

Superior view

Lateral view

• It is a It is a cartilagenouscartilagenous joint. joint.• The upper and lower The upper and lower

surfaces of the bodies of surfaces of the bodies of adjacent vertebrae are adjacent vertebrae are covered by thin plates of covered by thin plates of hyaline cartilage. hyaline cartilage.

• Sandwiched between the Sandwiched between the plates of hyaline cartilage is plates of hyaline cartilage is an an intervertebral disc of intervertebral disc of fibrocartilage fibrocartilage

• The collagen fibers of the The collagen fibers of the disc strongly unite the disc strongly unite the bodies of the two bodies of the two vertebrae.vertebrae.

JOINTS BETWEEN TWO VERTEBRAL BODIESJOINTS BETWEEN TWO VERTEBRAL BODIES


• The intervertebral discs are responsible The intervertebral discs are responsible for for one fourth of the length of the one fourth of the length of the vertebral columnvertebral column

• They are thickest in the cervical and They are thickest in the cervical and lumbar regions, where the movements lumbar regions, where the movements of the vertebral column are greatest.of the vertebral column are greatest.

• Each disc consists of a:Each disc consists of a: Peripheral part, the Peripheral part, the anulus anulus

fibrosusfibrosus, composed of , composed of fibrocartilage, fibrocartilage,

Central part, the Central part, the nucleus pulposusnucleus pulposus, , a mass of gelatinous material a mass of gelatinous material containing a large amount of containing a large amount of water, a small number of collagen water, a small number of collagen fibers, and a few cartilage cellsfibers, and a few cartilage cells. .

• No discs No discs are found between the first & are found between the first & second cervical vertebrae and in the second cervical vertebrae and in the sacrum or coccyx.sacrum or coccyx.

INTERVERTEBRAL DISCSINTERVERTEBRAL DISCS


• Allow one vertebra to rock forward or backward on another, as in flexion and extension of the vertebral column.

• Serve as shock absorbers when the load on the vertebral column is suddenly increased, as when one is jumping from a height.

• Sometimes, the annulus fibrosus ruptures, allowing the nucleus pulposus to herniate and protrude into the vertebral canal, where it may press on the spinal nerve roots, the spinal nerve, or even the spinal cord.

FUNCTION OF THE INTERVERTEBRAL DFUNCTION OF THE INTERVERTEBRAL DISCS


• The anterior and posterior The anterior and posterior longitudinal ligaments longitudinal ligaments run as run as continuous bands down the anterior continuous bands down the anterior and posterior surfaces of the and posterior surfaces of the vertebral column from the skull to vertebral column from the skull to the sacrumthe sacrum

• The anterior longitudinal ligament is The anterior longitudinal ligament is wide and is strongly attached to the wide and is strongly attached to the front and sides of the vertebral front and sides of the vertebral bodies and to the intervertebral bodies and to the intervertebral discs. discs.

• The posterior longitudinal ligament The posterior longitudinal ligament is weak and narrow and is attached is weak and narrow and is attached to the posterior borders of the discs.to the posterior borders of the discs.

LIGAMENTSLIGAMENTS


These ligaments hold the vertebrae firmly together but at the same time These ligaments hold the vertebrae firmly together but at the same time permit a small amount of movement to take place between them.permit a small amount of movement to take place between them.

• Consist of Consist of synovial synovial jointsjoints between the between the superior and superior and inferior articular inferior articular processes of processes of adjacent adjacent vertebrae. vertebrae.

JOINTS BETWEEN TWO VERTEBRAL ARCHESJOINTS BETWEEN TWO VERTEBRAL ARCHES


LIGAMENTSLIGAMENTS


Supraspinous Supraspinous ligament: ligament: runs runs between the tips between the tips of adjacent spinesof adjacent spines

Intertransverse Intertransverse ligament: ligament: runs runs between adjacent between adjacent transverse processestransverse processes

Ligamentum Ligamentum flavum: flavum: connects connects the laminae of the laminae of adjacent adjacent vertebraevertebraeInterspinous Interspinous ligamentligament: : connects adjacent connects adjacent spinesspines

• The following movements are possible on the spine: The following movements are possible on the spine: flexionflexion, , extensionextension, , lateral flexion, rotation, and circumduction.lateral flexion, rotation, and circumduction.

• The type and range of movements possible in each region of The type and range of movements possible in each region of the vertebral column largely depend on the:the vertebral column largely depend on the: Thickness of the intervertebral discsThickness of the intervertebral discs and theand the Shape and direction of the articular processes.Shape and direction of the articular processes.

• In the In the thoracic regionthoracic region, the ribs, the costal cartilages, and the , the ribs, the costal cartilages, and the sternum severely restrict the range of movement.sternum severely restrict the range of movement.

• Flexion, extension and lateral flexion Flexion, extension and lateral flexion are are extensive in the extensive in the lumbar regions lumbar regions but but restricted in the thoracic region.restricted in the thoracic region.

• RotationRotation is least extensive in the lumbar region. is least extensive in the lumbar region.

MOVEMENTS OF THE THORACOLUMBAR SPINEMOVEMENTS OF THE THORACOLUMBAR SPINE

14Dr. Zeenat & Dr. Vohra

MUSCLES PRODUCING MOVEMENTSMUSCLES PRODUCING MOVEMENTS

• In the In the thoracic regionthoracic region, rotation is produced by the , rotation is produced by the semispinalis and rotator muscles, assisted by the semispinalis and rotator muscles, assisted by the oblique muscles of the anterolateral abdominal wall.oblique muscles of the anterolateral abdominal wall.

• In the In the lumbar regionlumbar region::• FlexionFlexion is produced by the rectus abdominis and the psoas is produced by the rectus abdominis and the psoas

muscles.muscles.• ExtensionExtension is produced by the postvertebral muscles. is produced by the postvertebral muscles.• Lateral flexion Lateral flexion is produced by the postvertebral muscles, the is produced by the postvertebral muscles, the

quadratus lumborum, and the oblique muscles of the quadratus lumborum, and the oblique muscles of the anterolateral abdominal wall. The psoas may also play a part anterolateral abdominal wall. The psoas may also play a part in this movement. in this movement.

• RotationRotation is produced by the rotator muscles and the oblique is produced by the rotator muscles and the oblique muscles of the anterolateral abdominal wall.muscles of the anterolateral abdominal wall.


• Is the largest of all movable vertebrae. Is the largest of all movable vertebrae. • Is distinguished by its Is distinguished by its massive body massive body and and

thick transverse processes thick transverse processes • It carries the weight of the whole upper body. It carries the weight of the whole upper body. • The L5 The L5 bodybody is largely responsible for the is largely responsible for the

lumbosacral angle lumbosacral angle between the long axis of between the long axis of the lumbar region of the vertebral column and the lumbar region of the vertebral column and that of the sacrumthat of the sacrum

• Body weight is transmitted from L5 vertebra Body weight is transmitted from L5 vertebra to the base of the sacrum, formed by the to the base of the sacrum, formed by the superior surface of S1 vertebrasuperior surface of S1 vertebra

• The fifth lumbar vertebra is by far the most The fifth lumbar vertebra is by far the most common site of common site of spondylolysisspondylolysis and and spondylolisthesisspondylolisthesis


Vertebra L5Vertebra L5

Thank u & Good Luck


Documents

Thoracolumbar Spine Dr. Zeenat Zaidi & Dr. Saeed Vohra Dr. Zeenat Zaidi & Dr. Saeed Vohra Dr. Zeenat & Dr. Vohra 1