Anatomy of Human Spine presented diagrammatically.

1. ANATOMY AND BIOMECHANICS
OF SPINE
Dr. Javed Hassan Raza
MBBS,MD,FCPS,MRCS
HOD ORTHO UNIT 2
JHL,AIMC,LHR

2. WHAT IS SPINE

3. Extend of spine and construct
Spine extend from 1st cervical vertebrae to coccyx
Its length is 71cm in males and 61 in females
It comprises of total 33 vertebrae and 23 intervertebral disc.
• Cervical (7)
• Thoracic (12)
• Lumbar (5)
• Sacral (5)
• Coccygeal (4)

4. Planes of spine
There are 3 Anatomical planes of spine
1) Sagitta plane or Median plane
2) Coronal plane or Frontal plane
3) Axial or Transverse plane

5. Anatomical Planes
A-P X-ray of a
scoliotic spine in
the coronal plane.
The CORONAL PLANE, also
called the FRONTAL PLANE, is a
vertical cut that divides the body into
front and back sections.
Physicians look at the coronal plane
when they view an A-P (anterior-
posterior) x-ray of the spine to
evaluate scoliosis.

6. Lateral X-ray of a
kyphotic spine in
the sagittal
plane.
The SAGITTAL or MEDIAN
PLANE is a vertical cut that
divides the body into left and right
sections. The sagittal view is seen
by surgeons on a lateral x-ray of
the spine.
Anatomical Planes

7. CT Scan of a
thoracic vertebra
in the axial plane.
The AXIAL or TRANSVERSE
PLANE is a horizontal cut that
divides the body into upper and
lower sections. To best view the
axial plane of the spine, surgeons
will often obtain a CT scan with
axial cuts.
Anatomical Planes

8. Curves of spine
There are mainly two curves of spine
1) primary curves (kyphotic curves)
Thoracic and sacral region
2) secondary curves (Lordotic curves)
Cervical and lumbar region

10. Cervical Lordosis 20°- 40°
Thoracic Kyphosis 20°- 40°
Lumbar Lordosis 30°- 50°
Sacral Kyphosis

11. Regions of spine
• Cervical
– Upper cervical: C1-C2
– Lower cervical: C3-C7
• Thoracic: T1-T12
• Lumbar: L1- L5
• Sacrococcygeal: 9 fused
vertebrae in the sacrum and
coccyx.

13. • Protection of
– spinal cord and nerve roots
– internal organs
Functions of the Spine

14. • Flexibility of motion in six degrees of freedom
Left and Right
Side Bending
Flexion and Extension Left and Right Rotation
Functions of the Spine

15. • Structural support and
balance for upright posture
The spine is the axle bearing the load
of the head, shoulders and thorax. The
upper body weight is then distributed
to the lower extremities through the
sacrum and pelvis.
This reduces the amount of work
required by the spinal muscles and can
eliminate muscle fatigue and back pain.
Functions of the Spine

16. To achieve these functions, the spine
must have:
• Resistance to axial loading forces,
accomplished by:
– Kyphotic and lordotic sagittal plane
curves
– Increased mass of each vertebra
from C1 to the sacrum
• Elasticity accomplished by:
– Alternating lordotic and kyphotic
curves
– Multiple MOTION SEGMENTS
Functions of the Spine

17. • The FUNCTIONAL UNIT of the spine
• Composed of:
– Two adjacent
– v
Te
hr
e
te
in
btre
are
vertebral disc
– Connecting ligaments
– Two facet joints and
capsules
The Motion Segment

18. Basic Vertebral Structures
Cervical Thoracic Lumbar

19. Vertebral
Body
Pedicle
Superior
Articular
Process
Lamina
Spinous
Process
Transverse
Process
Vertebral
Foramen
Vertebral Structures

20. Superior
Articular
Process
Inferior
Articular
Process
Zygapophyseal
Joint
(Facet Joint)
Pars
Vertebral Structures

21. Vertebral Structures
• Pedicle notches
Slight
Notch
Deep
Notch
Intervertebral
Foramen
• INTERVERTEBRAL FORAMEN
through which the spinal nerve
roots leave the spinal cord

22. • Anterior Arch
Comprised of:
– Vertebral body
– Anterior 1/3 of the pedicles
• Posterior Arch
Comprised of:
– Posterior 2/3 of the pedicles
– Lamina
– Processes
Vertebral Arches

23. FEATURES OF CERVICAL VERTEBRAE

24. The Atlas (C1)
Transverse
Process
Transverse
Foramen
Anterior
Tubercle
Articular Facet
for Dens
Lateral
Mass
Lamina
Posterior
Tubercle
Superior
Articular
Facet
Superior View

25. The Axis (C2)
Odontoid
Process
(Dens)
Body
Transverse
Process
Superior
Articular
Facet
Inferior
Articular
Facet
Anterior View
Lateral
Mass
Spinous
Process
Posterior View

26. Lower Cervical Vertebrae
C3 - C7
Transverse
Process
Body
Sulcus for
Spinal Nerve
Lateral
Mass
Lamina
Pedicle
Superior
Articular Facet
Vertebral
Foramen
Bifid Spinous Process
Transverse
Foramen
Axial View

27. Sulcus for
Spinal Nerve
Uncovertebral Joint
(Joint of Luschka)
Lower Cervical Vertebrae
C3 - C7
Anterior View
The vertebral bodies of the subaxial cervical spine have upward projections on
the lateral margins called UNCINATE PROCESSES.
These processes articulate with the level above to form the UNCOVERTEBRAL
JOINT. These are also called JOINTS OF LUSCHKA.
Uncinate
Process

28. FEATURES OF THORACIC VERTEBRAE

29. Thoracic Vertebrae, T1-T12
• Body - heart shaped when viewed
superiorly.
• Vertebral foramen - round
• Pedicles - small in diameter
• Spinous processes - long and
projected downwards

30. • Articular processes
Superior Articular
Process
Inferior Articular
Process
Thoracic Vertebrae, T1-T12

31. FEATURES OF LUMBAR VERTEBRAE

32. • Body - L1 to L5 progressive increase
in mass
• Pedicles - longer and wider than
thoracic; oval shaped
• Spinous processes - horizontal,
square shaped
• Transverse processes - smaller than
in thoracic region
• Intervertebral foramen - large, but
with increased incidence of nerve
root compression
Lumbar Vertebrae, L1-L5

34. FEATURES OF SACRAL/ COCCYGEAL VERTEBRAE

35. S1 VERTEBRAE

36. The Sacrum
Sacral Horns
Sacral Ala
Dorsal
Foramina
Pedicles
Sacral
Hiatus
Coccyx
Posterior View
Inverted triangle shape

37. Coccyx
Lateral View
Sacral
Promontory
Sacral Tilt
30°-60°
Sacral Canal
1
2
3
4
5
Sacral Hiatus
The Sacrum

38. COMPARISON OF VERTEBRAE
Cervical

39. Sacral vertebrae

41. Thank You!