The pelvic joints include the lumbosacral joint, sacrococcygeal joint, intercoccygeal joints, and sacroiliac joint. The lumbosacral joint connects the fifth lumbar vertebrae to the sacrum. It allows limited axial rotation and is stabilized by ligaments like the iliolumbar ligament. The sacroiliac joints connect the sacrum to the ilium bones and allow for some anteroposterior rotational movement to absorb shock. Strong ligaments like the interosseous ligament provide stability to the sacroiliac joints. The pubic symphysis joins the right and left pubic bones and transmits weight from

1. PELVIC JOINT
DR SANA YASEEN
ANATOMY DEPARTMENT

2. • The joints can be describe as:
Lumbosacral joint
Saccrococcygeal and inter coccygeal joints
Sacro-iliac joint
Pubic symphysis

3. LUMBOSACRAL JOINT
• Is like intervertebral joint between
L5 and first segment of sacrum.
Type:
• Between bodies- secondary
cartilaginous
• Between articular processes-
synovial type
• Between other processes- fibrous
type

4. LIGAMENTS:
• Anterior & posterior longitudinal ligament
• Intertransverse, interspinous ligament & ligamentum
flavum
All these are intervertebral joints ligament
• Iliolumbar ligament
FUNCTION:
LIMITS THE AXIAL ROTATION OF 5TH LUMBAR
VERTEBRAE ON SACRUM

6. Stability of joint:
• Forward and downward displacement of 5th lumbar ver.
During transmission of weight is prevented by:
Ilio lumbar ligament
Widely spaced articular processes with interlocking
arrangements
Strong intervertebral disc
Prominent lumbosacral angle of 120 deg.

8. APPLIED ASPECT
Backache occurs due to pressure in the nerves in these
region due to variations in lumbosacral joints
Lumbarisation of first vertebrae (fusion)
Sacralisation of 5th lumbar vertebrae (fusion)
Spina bifida
spondylolisthesis

9. SACRO-ILIAC JOINT
• They are pair of joint on
each side of sacrum in
posterior part of pelvis
• Type: synovial joint
• Sub type: plane variety

10. • Articular capsule:
a. Fibrous capsule enveloping the joint
b. Synovial membrane- lines inner aspect of fibrous capsule and
extends from one cartilage to another but doesnot cover the
cartilage
• Articular surface:
– Auricular surface of sacrum, covered by fibrocartilage.
– Auricular surface of ilium, covered with hyaline cartilage.

11. LIGAMENTS OF SACRO ILIAC JOINT
• Fibrous capsule lined by synovial joint
• Ventral sacroiliac ligament
• Dorsal sacroiliac ligament
• Interrosseous ligament:
• Ligaments between vertebrae and pelvis
– Iliolumbar ligament
– Sacrotuberous ligament:
– Sacrospinous ligament:

13. Interrosseous ligament:
Is a ligament of the sacroiliac joint that lies deep to the
posterior ligament, and consists of a series of short, strong
fibers connecting the tuberosities of the sacrum and ilium. It
is the strongest ligament in the body.

15. – Iliolumbar ligament: between 5th lumbar vertebrae to posterior
part of inner lip of iliac crest.
– Sacrotuberous ligament: is long and strong band which forms
part of boundaries of the pelvic outlet and sciatic foramina.
extend from posterior superior and posterior inferior iliac spine,
ischial tuberosity to tubercle and lateral margin of lower part of
sacrum and upper part of coccyx.
- Sacrospinous ligament: extends from sacrum and coccyx to
ischial spine.

17. Movements:
Antero-posterior rotatory movement around transverse axis below
sacral promontory during flexion and extension of trunk.
This movement absorbs shock during jumping, loading and
transmission of weight.
Total movt 5-10cm
In females this movement increases for easy labour.
Stability: requires for transmission of weight
Factors:
• Ligament of joint
• Interlocking arrangement of articular surfaces
• Synostosis in advance age

19. PUBIC SYMPHYSIS
• Is secondary
cartilaginous joint.
• Formed between right
and left pubic bone
• Articular surface is
covered by thin layer of
hyaline cartilage.
• The joint is surrounded
by ligaments to
reinforced the disc.

20. Function:
• Transmit weight of upper trunk and limb to lower trunk.
• Allows slight movement between the hip bones, helping in
absorbing shock.

22. SACROCOCCYGEAL JOINT
• Is intervertebral articulation between apex of sacrum and
base of coccyx
• Type: sec. cartilaginous joint
Ligaments:
• Ventral sacroccoccygeal ligament
• Dorsal coccygeal ligament
• Lateral coccygeal ligament
• Intercornual ligament

23. • Action: backward
movement of coccyx
during defeacation
• In old age joint is
obliterated by ossification
of disc and ligament esp
in males

24. MECHANISM OF PELVIS
Theoretally is divided in to two;
• One component of force is expanded, driving sacrum down and
backward between iliac bones
• Second component pushes upper end of sacrum downward and
forward the pelvic cavitythis is restricted by sacroiliac joint, where
articular surface of sacrum is wider posteriorly.
During all these movements separation of iliac bones is restricted by
sacroiliac & iliolumbar ligament, and ligaments of pubic
symphysis.