The cranio-vertebral joints include the atlanto-occipital and atlanto-axial joints. The atlanto-occipital joints are ellipsoid synovial joints that allow flexion, extension, and lateral flexion. They are connected by capsular ligaments and anterior/posterior membranes. The atlanto-axial joints include median and lateral joints, with the median being a pivot joint formed by the dens and anterior arch. Ligaments like the alar and apical stabilize the joints. Together these joints allow rotation and flexion/extension of the head.

1. CRANIO-VERTEBRAL
JOINTS
DR. SUNDIP CHARMODE
ASSOCIATE PROFESSOR
DEPARTMENT OF ANATOMY
AIIMS RAJKOT

2. INTRODUCTION
• They include :
1. Atlanto-occipital joints
2. Atlanto-axial joints
3. Ligaments connecting Axis with Occipital
bone
4. Ligamentum Nuchae

3. ATLANTO-
OCCIPITAL JOINTS

5. INTRODUCTION
 They are a pair of Ellipsoid type of Synovial
joints.
 They are supplied by First cervical nerve.

6. ARTICULATING BONES
 Superior articulating facet of Lateral mass of
atlas :
• Concave, directed upwards and medially,
Kidney shaped,
• Sometimes constricted in middle.
 Condyle of Occipital bone : Reciprocally
curved

7. PECULARITIES
 Corresponding articular surfaces of the two
sides are set :
 Obliquely
 Backwards, medially and forwards.
 Hence, they represent surface of one ellipsoid
and move as a single unit.

8. AXES
 Movements take place at :
1. Transverse axis
2. Antero-posterior axis

9. LIGAMENTS
1. Capsular Ligament
2. Anterior Atlanto-occipital Membrane
3. Posterior Atlanto- Occipital Membrane

10. CAPSULAR LIGAMENT
1. Loosely envelops each joint and attached to
the peripheral margins of articular surfaces.
2. The capsule is lined internally lined by
Synovial membrane.

11. ANT. ATLANTO-OCCIPITAL MEMBR.
1. It connects Anterior Arch of Atlas with
Anterior margin of Foramen magnum.
2. On sides, it blends with capsular ligament.

13. POST. ATLANTO-OCCIPITAL MEMBR.
1. It connects Upper margin of Posterior Arch of
Atlas with Posterior margin of Foramen
magnum.
2. It presents a concave free margin for the
passage of Vertebral artery and First cervical
nerve.

15. MOVEMENTS
1. Flexion and Extension - around Transverse
axis
2. Lateral flexion - around Antero-posterior
axis

16. MUSCLES PRODUCING MOVEMENTS
1. Flexion : Rectus Capitis Anterior, Longus
Capitis, Sterno-cleido-mastoid.
2. Extension : Rectus Capitis Posterior Major
And Minor, Obliquus Capitis Superior,
Semispinalis Capitis, Splenius Capitis, Upper
Part Of Trapezius.

17. MUSCLES PRODUCING MOVEMENTS
3. Lateral flexion : Rectus Capitis Lateralis,
Semispinalis Capitis, Splenius Capitis, Sterno-
cleido-mastoid And Upper Part Of Trapezius

18. ATLANTO-AXIAL
JOINTS

20. INTRODUCTION
 They comprise of three separate joints.
1. Median Atlanto-axial joint
2. Lateral Atlanto-axial joint (2)
 They are supplied by Second cervical nerve.

21. MEDIAN
ATLANTO-AXIAL
JOINT

22. INTRODUCTION
• It is a pivot joint.
ARTICULATING BONES
1. Dens or Odontoid process of Axis : Oval
facet on its anterior surface.
2. Anterior Process of Atlas : Corresponding
facet on posterior surface.

23.  The is kept in position by Transverse ligament
of Atlas.
 The Pilot is formed by :
1. Dens
2. The Ring by the Anterior arch
3. Transverse ligament of Atlas.

24.  The Tip of Dens gives attachment to :
• Apical ligament – extent ?
• A pair of Alar ligaments – extent ?
• Alar ligaments are stretched during Flexion
• Relaxed during Extension
• Check excessive rotation at Atlanto-axial
joints.

25. LATERAL
ATLANTO-AXIAL
JOINT

26. INTRODUCTION
• Each joint is a plane synovial joint.
ARTICULATING BONES
• Inferior articulating facet of Lateral mass of
Atlas - concave
• Superior articulating facet of Axis - convex

27. MOVEMENTS
• Lateral Atlanto-axial joints – Atlas carrying the
globe of head rotates around the Dens of Axis.
• Transmit the weight of the skull through
Atlanto-axial joints.

28. MOVEMENTS
• The Atlas also descends on the Axis while
movement at Atlanto-axial joints.
• Alar ligaments permit rotation and are relaxed
at initial stage but as full range is reached,
excess rotation is checked by Alar ligaments.

29. MUSCLES CAUSING MOVEMENTS
• Obliquus Capitis Inferior, Rectus Capitis
Posterior Major and Splenius Capitis on each
side acting along with,
• Sternocleidomastoid of contralateral side.

30. LIGAMENTS CONNECTING AXIS
AND OCCIPITAL BONE
 They bypass ?
1. Apical Ligament
2. Alar Ligament
3. Cruciform Ligament
4. Membrana Tectoria

33. CRUCIFORM LIGAMENT
• It consists of :
1. Horizontal band
2. Vertical band.
 Horizontal band : Transverse Ligament of Atlas
connecting the tubercles on the medial side of
lateral masses of Atlas.
 It passes behind the root of Dens thereby
retaining it in position.

34. CRUCIFORM LIGAMENT
• Opposite the Dens, the Vertical band extends
above and below from Upper and Lower
margin of Transverse ligament respectively.
• Above : Upper surface of Basilar part of
Occipital bone between Apical ligament and
Membrana Tectoria.
• Below : Posterior surface of Body of Axis.

37. MEMBRANA TECTORIA
• It lies within the vertebral column and in
intimately adherent of Spinal dura.
• It is the upward continuation of Posterior
Longitudinal ligament.
• It extends from Posterior surface of Body of
Axis to the Upper surface of Basilar part of
Occipital bone.

40. LIGAMENTUM NUCHAE
 Beneath the Skin of nape, in median plane, is a
triangular fibrous sheet representing upward
continuation of Supra-spinous ligament called
 Posterior border is free.
 Anterior border is attached to cervical spines.
 Superior border is attached to External occipital
crest and Ext. Occipital Protuberance.
 It separates muscles of ?

44. APPLIED ANATOMY
During Judicial hanging
Rupture of Transverse Ligament of Atlas /
Fracture of Dens of Axis
Displacement of Atlas from Axis
Compression of Spinal cord

45. • Hanging - Afghanistan, Bangladesh, Botswana,
India, Iraq, Japan, Kuwait, Malaysia, Nigeria, the
Palestinian Authority in Gaza, South Sudan and
Sudan.
• Firing – Indonesia, China, North Korea, Saudi
Arabia, Somalia, Taiwan and Yemen, United Arab
Emirates, Thialand (old).
• Beheading – Saudi arabia
• Lethal injection – US, China, Vietnam, Thialand
(now).
• Electrocution – US
• Stoning - Indonesia, Iran, Mauritania, Nigeria,
Pakistan, Saudi Arabia, Sudan, United Arab
Emirates, and Yemen.
• Gas chamber - US