Los Angeles Academy of Figurative Art

Kaan Yücel M.D., Ph.D. 10.January.2014 Friday

inferoposterior to the abdomen

transition between the trunk

and the lower limbs

.

L. Basin

Right hip bone Left hip bone

Sacrum

Coccyx

A ring of 3 bones connects the vertebral column to the two femora

Right and left hip bones

coxal bones; pelvic bones

Sacru

m

Bear the weight of the upper body

Transfer that weight lower appendicular skeleton

Provide attachment for muscles of locomotion,posture & abdominal wall

strong and rigid Contain and protect the pelvic viscera

Provide support for the abdominopelvic viscera and gravid (pregnant) uterus

Provide attachment for the erectile bodies of the external genitalia.

Provide attachment for the muscles and membranes

Superior, fan-shaped part of the hip bone

Ala, or wing, of the ilium spread of the fan

Body of the ilium, the handle of the fan.

On its external aspect, the body participates in formation of the

acetabulum.

from the lateral margin of the iliac crest arches inferiorly across the ilium

vertically from the iliac crest to a position near the posterior inferior iliac spine

originates superior to the AIIS and ends near the posterior margin of the acetabulum.

Gluteal surface down the iliac crest

an angulated bone Superior ramus helps form the acetabulum

Inferior ramus helps form the obturator foramen.

Pubic crest thickening on the anterior part of the body

Pubic tubercle Pubic crest ends laterally as a prominent swelling

Pecten pubis Oblique ridge@ lateral part of superior pubic ramus

Distinct features of the pelvic bone

acetabulum

obturator foramen/canal

greater sciatic notch

lesser sciatic notch

Greater (false) pelvis

Lesser (true) pelvis

by the oblique plane of the pelvic inlet (superior pelvic aperture).

The bony edge (rim) surrounding and defining the pelvic inlet

Formed by: Promontory and ala of the sacrum A right and left linea terminalis (terminal line)

formed by

ischiopubic rami

inferior rami of the pubis + ischium of the 2 sides.

Meet @ pubic symphysis its inferior border -subpubic angle The width of the subpubic angle is determined by the distance between the right and the

left ischial tuberosities, which can be measured with the gloved fingers in the vagina

during a pelvic examination.

bounded by:

pubic arch anteriorly

ischial tuberosities laterally

sacrotuberous and sacrospinous ligaments posterolaterally

tip of the coccyx posteriorly

Pelvic outlet (inferior pelvic aperture)

iliopubic eminence (iliopectineal eminence) a raised area below he anterior inferior iliac spine

marks the point of union of the ilium and pubis.

constitutes a lateral border of the pelvic inlet.

Circular opening between abdominal cavity & pelvic cavity

Formed Anteriorly by pubic symphysis Posteriorly by sacrum (promontory in the middle) Laterally by iliopectineal line

Part of the pelvis superior to the pelvic inlet

bounded by

iliac alae posterolaterally

anterosuperior aspect of the S1 posteriorly

Occupied by abdominal viscera ileum and sigmoid colon.

between pelvic inlet & pelvic outlet

bounded by pelvic surfaces of the hip bones, sacrum, and coccyx.

includes true pelvic cavity & deep parts of the perineum.

Major obstetrical and gynecological significance.

The blue line in this 3-D volume

rendered CT image (above)

represents the linea terminales that

separates the false pelvis, which is

above it from the true pelvis below it.

The false pelvis consists of the iliac

wings and has no anterior wall. The

pubis bones, sacrum and coccyx,

and both ischium bones delimit the

false pelvis.

arcuate line + pecten pubis+ pubic crest

Linea terminalis

smooth rounded border on the internal surface of the ilium. immediately inferior to the iliac fossa. Forms part of the border of the pelvic inlet.

Arcuate line of the ilium

The primary joints

Sacroiliac joints & pubic symphysis

Sacroiliac joints link axial skeleton & inferior appendicular skeleton. Lumbosacral & sacrococcygeal joints, although joints of the axial skeleton, are directly related to the pelvic girdle. Strong ligaments support and strengthen these joints.

Joints and Ligaments of Pelvic Girdle

Strong, weight-bearing compound joints An anterior synovial joint between the earshaped auricular surfaces of the sacrum & ilium

A posterior syndesmosis between the tuberosities of the same bones

Differ from most synovial joints limited mobility is allowed, a consequence of their role in transmitting the weight of most of the body to the hip bones.

Weight from the axial skeleton:

Sacroiliac ligaments ilia

Femurs –during standing-

Ischial tuberosities –during sitting-

Sacrum is actually suspended between the iliac bones

Firmly attached to iliac bones by posterior and interosseous

sacroiliac ligaments.

Anterior sacroiliac ligaments

Anterior part of the fibrous capsule of the synovial part of the joint.

Interosseous sacroiliac ligaments

Lie deep between the tuberosities of the sacrum and ilium.

Primary structures involved in transferring the weight.

Posterior sacroiliac ligaments

Posterior external continuation of the same mass of fibrous tissue.

Formed by posterior sacroiliac ligaments

Passes from posterior ilium, lateral sacrum & coccyx to ischial tuberosity

Transforms the sciatic notch of the hip bone into a large sciatic foramen.

Sacrospinous ligament from lateral sacrum & coccyx to ischial spine

subdivides sciatic foramen into

greater and lesser sciatic foramina.

Most of the time, movement at the sacroiliac joint is limited by interlocking of

the articulating bones and the sacroiliac ligaments.

By allowing only slight upward movement of the inferior end of the

sacrum relative to the hip bones, resilience is provided to the sacroiliac

region when the vertebral column sustains sudden increases in force or

weight.

Secondary cartilaginous joint A fibrocartilaginous interpubic disc & surrounding ligaments uniting the bodies of the pubic bones in the median plane. Interpubic disc wider in women.

superior & inferior margins of the symphysis Superior pubic ligament connects the superior aspects of the pubic bodies and interpubic disc. Inferior (arcuate) pubic ligament connect the inferior aspects of the joint components round off the subpubic angle as it forms the apex of the pubic arch.

Superior & inferior pubic ligaments

L5 & S1 articulate Anterior intervertebral (IV) joint formed by L5/S1 IV disc

between their bodies

& 2 posterior zygapophysial joints (facet joints) between the articular processes of these vertebrae

Fan-like iliolumbar ligaments radiate from the transverse processes of the L5 vertebra to the ilia.

Secondary cartilaginous joint with an intervertebral disc. Fibrocartilage & ligaments join apex of the sacrum base of coccyx.

Anterior & posterior sacrococcygeal ligaments

long strands that reinforce the joint.