Transcript Clinical Anatomy of the Pelvis

Kaan Yücel M.D., Ph.D.
14.January.2014 Tuesday
Sexual differences are related mainly
1. Heavier build and larger muscles of most men
2. Adaptation of the pelvis (particularly the lesser pelvis)
in women for parturition (childbearing).
The difference
between the male
and female pelvis
Difference
Between Male
& Female
Pelvis
male or funnel-shaped pelvis with a
contracted outlet
41% of women
long, narrow, and oval shaped
wide pelvis 2% of women
 In forensic medicine (the application of medical and anatomical
knowledge for the purposes of law), identification of human
skeletal remains usually involves the diagnosis of sex.
 A prime focus of attention is the pelvic girdle because sexual
differences usually are clearly visible.
 Even fragments of the pelvic girdle are useful in determining
sex.
Feature
General
Structure
Male pelvis
Female pelvis
Thick & Heavy
Thin & Light
Greater
pelvis
Deep
Shallow
Lesser
pelvis
Narrow and deep,
tapering
Wide and shallow,
cylindirical
Heart-shaped, narrow
Oval and rounded, wide
Comparatively small
Comparatively large
Project further medially
into the pelvic cavity
Do not project as far medially
into the pelvic cavity & smooth
Pelvic inlet
Pelvic outlet
Ischial
spines
Feature
Male pelvis
Obturator
foramen
Round
Oval
Acetabulum
Large
Small
Narrow, inverted V
(approximately 70
degrees)
Almost 90 degrees
Smaller
(50-60 degrees)
Larger
(80-85 degrees)
Prominent
Not prominent
Greater
schiatic
notch
Subpubic
angle
Sacral
promontory
Female pelvis
PELVIC DIAMETERS (CONJUGATES)
Size of the lesser pelvis important in obstetrics
Because it is the bony canal through which the fetus passes
during a vaginal birth.
To determine the capacity of the female pelvis for childbearing,
diameters of the lesser pelvis are noted radiographically or
manually during a pelvic examination.
PELVIC DIAMETERS (CONJUGATES)
Diameters of pelvic outlet
Antero - posterior diameters
Anatomical antero-posterior diameter 11cm
from tip of the coccyx to lower border of symphysis pubis
Obstetric antero-posterior diameter 13 cm
from tip of the sacrum to lower border of symphysis pubis
as the coccyx moves backwards during the second stage of labour.
Diameters of pelvic outlet
Bituberous diameter 11 cm
between inner aspects of ischial tuberosities
Bispinous diameter 10.5 cm
between tips of ischial spines
Transverse diameters
Diameters of pelvic inlet
Antero - posterior diameters
Anatomical antero-posterior diameter True conjugate 11cm
from tip of sacral promontory to upper border of symphysis pubis
Diameters of pelvic inlet
Antero - posterior diameters
Obstetric conjugate 10.5 cm
from tip of sacral promontory to
the most bulging point on back of symphysis pubis ,about 1 cm below its upper
border.
shortest antero-posterior diameter
Diameters of pelvic inlet
Antero - posterior diameters
Diagonal conjugate 12.5 cm
1.5 cm longer than the true conjugate
From tip of sacral promontory to lower border of symphysis pubis
Minimum anteroposterior (AP) diameter of the lesser pelvis
True (obstetrical) conjugate
Narrowest distance through which the baby's head
must pass in a vaginal delivery.
This distance, however, cannot be measured directly during a pelvic
examination because of the presence of the bladder.
Diagonal conjugate (from inferior pubic lig. to promontory)
Measured by palpating sacral promontory with the tip of the middle
finger, using the other hand to mark the level of the inferior margin of
the pubic symphysis on the examining hand.
After the examining hand is withdrawn, the distance between the tip of the
index finger (1.5 cm shorter than the middle finger) and the marked level of the
pubic symphysis is measured to estimate the true conjugate, which should be
11.0 cm or greater.
Transverse diameter is the greatest distance between the linea
terminalis on either side of the pelvis.
 Anteroposterior compression of the pelvis occurs during
crush accidents (as when a heavy object falls on the pelvis).
 This type of trauma commonly produces fractures of the
pubic rami.
 When the pelvis is compressed laterally, the acetabula and
ilia are squeezed toward each other and may be broken.
Fractures of the bony pelvic ring are almost always multiple
fractures or a fracture combined with a joint dislocation.
Pelvic fractures can result from direct trauma to the pelvic
bones, such as occurs during an automobile accident, or be
caused by forces transmitted to these bones from the lower
limbs during falls on the feet.
Weak areas of the pelvis, where fractures often occur:
Pubic rami
Acetabula
Region of the sacroiliac joints
Alae of the ilium
25 Year Old Male
with displaced
fracture of the
sacrum and
symphysis pubis.
The most severe
pelvic fractures
separate the two
sides of the pelvis
from each other.
Pelvic fractures may cause injury to pelvic soft tissues, blood
vessels, nerves, and organs.
Fractures in the pubo-obturator area are relatively common and
are often complicated because of their relationship to the urinary
bladder and urethra, which may be ruptured or torn.
Sacroiliac joint dysfunction
Degenerative arthritis (osteoarthritis)
Pregnancy
Gout
Rheumatoid arthritis
Psoriasis
Ankylosing spondylitis
X-ray of the sacroiliac joints showing joint space narrowing, erosive change and indistinct margins, due to sacroiliitis