obstetrical condition

1. FEMALE PELVIS
MS.BRITO

2. INTRODUCTION
• IT IS A SKELETAL RING FORMED BY
TWO INNOMINATE OR HIPBONES,
THE SACRUM, AND THE COCCYX.

3. INNOMINATE BONE
• EACH INNOMINATE BONE IS MADE UP OF 3
PARTS,
1.ILIUM
2.ISCHIUM
3.PUBIS

4. ILIUM:
IT IS THE LARGE FLARED OUT PORTION OF
THE INNOMINATE BONE.
THE ANTERIOR SURFACE OF THE ILIUM IS
CONCAVE IN SHAPE AND TERMED AS THE
ILIAC FOSA.
THE UPPER BORDER OF ITS ANTERO
POSTERIOR ILIAC SPINE BELOW IS THE
ANTERIO INFERIOR ILIAC SPINE.

5. • ISCHEUM:
 IT IS THE THICK LOWER PART OF THE INNOMINATE
BONE.
 IT HAS A LARGE PROMINANCE KNOWN AS THE
ISCHIAL TUBEROSITY.
 IN SITTING POSITION, THE BODY RESTS ON THE
ISCHIAL TUBEROSITY.
 A LITTLE AND ABOVE AND BEHIND THE TUBEROSITY
IS A PROJECTION KNOWN AS THE ISCHIAL SPINE.
 IN LABOR THE STATION OF THE FETAL HEAD IS
ESTIMATED IN RELATION TO THE ISCHIAL SPINES.

6. • PUBIC BONES:
THE PUBIC BONES FORM THE ANTERIOR PART OF
THE INNOMINATE BONE.
 IT HAS A BODY AND TWO OAR – LIKE
PROJECTIONS CALLED SUPERIOR AND INFERIOR
RAMES.
THE TWO PUBIC BONES MEET AT THE SYMPHYSIS
PUBIS.
THE TWO INFERIOR RAMI FORM THE PUBIC
ARCH.

7. THE SPACE ENCLOSED BY THE BODY OF THE PUBIC
BONE, THE RAMI AND THE ISCHIUM IS CALLED THE
OBTURATOR FORMEN.
THE INNOMINATE BONE HAS A DEEP CUP TO
RECEIVE THE HEAD OF THE FEMUR, WHICH IS
TERMED AS ACETABULUM.
ON THE LOWER BORDER OF THE INNOMINATE
BONE ARE FOUND TWO CURVES.
ONE EXTENDS FROM THE POSTERIOINFERIOR ILIAC
SPINE UP TO THE ISCHIAL SPINE AND IS CALLED
THE GREATER SCIATCH NOTCH.
THE OTHER LIES BETWEEN ISCHIAL SPINE AND THE
ISCHIAL TUBEROSITY IS THE LESSER SCIATIC
NOTCH.

8. SACRUM
 IT IS A WEDGE SHAPED BONE CONSISITING OF FIVE
VERTEBRAE FUSED TOGETHER.
THE PROMINENT UPPER MARGIN OF THE FIRST SACRAL
VERTEBRAE IS CALLED THE SACRAL PROMONTRY.
THE ANTERIOR SURFACE OF THE SACRUM IS CONCAVE
AND IS REFERRED TO AS THE HOLLOW OF THE SACRUM.
5 PAIRS OF HOLE OR FORMAINA PEIERCE THE SACRUM
AND THROUGH THESE, THE SACRAL NERVE PASS.

9. COCCYX
 THE COCCYX IS A SMALL TRIANGULAR BONE
WITH ITS BASE UPPERMOST ARTICULATING
WITH THE LOWER END OF THE SACRUM.
DURING LABOR, IT MOVES BACKWARD,
ALLOWING MORE SPACE FOR THE DELIVERY
OF THE FETUS.

10. PELVIC JOINTS
• 2 SACRO ILIAC JOINT
• 1 SYMPHYSIS PUBIS
• 1 SACRO COCCYGEAL JOINTS

11. PELVIC LIGAMENTS
• SCARO ILIAC LIGAMENTS
• PUBIC LIGAMENTS
• SACRO TUBEROUS LIGAMENTS
• SACROSPINOUS LIGAMENTS
• SACRO COCCYGEAL LIGAMENTS

12. DIVISION OF PELVIS
• TRUE PELVIS
• FALSE PELVIS
TRUE PELVIS:
SUPERIORLY- THE SACRAL PROMONTRY , LINES TERMINALIS
AND THE UPPER MARGIN OF THE PUBIC BONES.
INFERIORLY- THE INFERIOR MARGIN OF THE ISCHIAL
TUBEROSITIES AND THE TIP OF COCCYX.
LATERALLY – THE SACRO ILLIAC NOTCHES AND LIGAMENTS
AND THE INNER SURFACE OF ISCHIAL BONES.
ANTERIORLY- THE OBTRURATOR FORAMINA AND THE
POSTERIOR SURFACE OF THE SYMPHYSIS PUBIS, PUBIC
BONES, AND THE ASCENDING RAMI OF ISCHIAL BONES.

13. FALSE PELVIS
• LIES ABOVE AN IMAGINARY LINE CALLED LINIA
TERMINALIS AT THE LEVEL OF BRIM.
FUNCTIONS OF THE FALSE PELVIS IS TO
SUPPORT THE ENLARGED UTERUS.

14. SHAPE OF THE PELVIS
• THERE ARE 4 TYPES OF PELVIC SHAPES BASED
ESSENTIALLY ON THE SHAPE OF THE BRIM.
1.GYNECOID (NORMAL FEMALE PELVIS) : HAS
OPTIMAL DIAMETERS IN ALL THREE PLANES .
SEEN IN 50% OF WOMEN.
2.ANDROID (NORMAL MALE PELVIS) : POSTERIOR
SEGMENT ARE DECREASED IN ALL 3 PLANES.
DEEP TRANSVERSE ARREST AND FAILURE OF
ROTATION OF THE FETUS ARE COMMON. SEEN IN
20% OF ALL WOMEN.

15. 3. ANTHROPOID ( APELIKE PELVIS ) :
ANTEROPOSTERIOR DIAMETER IS LONGER,
MAY ALLOW FOR EASY DELIVERY OF AN
OCCIPUT POSTERIOR PRESENTATON OF FETUS.
SEEN IN 25% OF ALL WOMEN.
4. PLATYPELLOID ( FLAT FEMALE PELVIS WITH
TRANSVERSE DIAMETER ) : ARREST OF FETAL
DESCEND AT THE PELVIC INLET IS COMMON.
THIS TYPE OF PELVIS IS SEEN IN 5% OF ALL
WOMEN.

16. PELVIC BRIM
• THE BRIM IS ALSO TERMED AS THE INLET. ITS
BOUNDARIES ARE THE SACRAL PROMONTORY
AND WINGS OF THE SACRUM BEHIND THE
ILIAC BONE ON THE SIDES AND THE PUBIC
BONES IN FRONT.

17. LANDMARKS OF THE BRIM
1. SACRAL PROMONTRY
2. SACRAL ALA OR SACRAL WING.
3. SACRO ILIAC JOINT
4. ILIO PECTINEAL LINE
5. ILIO PECTINEAL EMINENCE
6. SUPERIOR RAMUS OF THE PUBIC BONES
7. UPPER INNER BORDER OF THE BODY OF PUBIC
BONE.
8. UPPER INNER BORDER OF THE BODY OF
SYMBHYSIS PUBIS .

18. DIAMETERS OF THE PELVIC BRIM
• INLET
• CAVITY
• OUTLET

19. INLET
1.ANTERO – POSTERIOR :
A) TRUE CONJUGATE , ANATOMICAL CONJUGATE,
CONJUGATE VERA : IT IS THE DISTANCE BETWEEN THE
MIDPOINT OF THE SACRAL PROMONTRY TO THE
INNER MARGIN OF THE UPPER BORDER OF SYMBYSIS
PUBIS. IT MEASURES ABOUT 11 CM.
B) OBSTETRIC CONJUGATE : IT IS THE DISTANCE
BETWEEN THE MID – POINT OF THE SACRAL
PROMONTRY TO THE INNER SURFACE OF THE
MIDLINE OF SYMPHYSIS PUBIS.IT MEASURES ABOUT
10 CM.

20. C) DIAGONAL CONJUGATE : IT IS THE DISTANCE
BETWEEN THE LOWER BORDER OF SYMBYSIS
PUBIS TO THE MIDPOINT ON THE SACRAL
PROMONTRY. IT MEASURES 12 CM.
2. TRANSVERSE DIAMETRE: IT IS THE DISTANCE
BETWEEN THE TWO FARTHEST POINTS ON THE
PELVIC BRIM OVER THE ILOPECTINEAL LINES. IT
MEASURES 13 CM.
3.OBLIQUE DIAMETRE: THERE ARE 2 OBLIQUE
DIAMETERS – RIGHT & LEFT .EACH ONE EXTENDS
FROM ONE SACROILIAC JOINT TO THE OPPOSITE
ILO PUBIC EMINENCE. IT MEASURES 12CM.

21. 4. SACRO COTYLOID : IT IS THE DISTANCE
BETWEEN THE MID POINT OF THE SACRAL
PROMONTORY TO ILIO PUBIC EMINENCE . IT
MEASURES 9.5 CM.

22. CAVITY
1. ANTERO – POSTERIOR : IT IS THE DISTANCE
BETWEEN THE POSTERIOR SURFACE OF THE
SYMPHYSIS PUBIS TO THE JUNCTION OF 2ND
AND 3RD SACRAL VERTEBRAE. IT MEASURES 12
CM.
2. TRANSVERSE DIAMETRE : IT CANNOT BE
PRECISELY MEASURED AS THE POINTS LIE OVER
THE SOFT TISSUES COVERING THE SACROSCIATIC
NOTCHES AND OBTRUATOR FORAMINA. IT
MEASURES 12 CM.

23. OUTLET – OBSTETRICAL OUTLET
1. TRANSVERSE (BISPINOUS ) : IT IS THE DISTANCE
BETWEEN THE TIP OF TWO ISCHIAL SPINES. IT
MEASURES 10.5 CM
2. ANTERO – POSTERIOR : IT IS THE DISTANCE
BETWEEN INFERIOR BORDER OF THE SYMBYSIS
PUBIS TO THE TIP OF THE SACRUM. IT
MEASURES 11 CM
3. POSTERIOR SAGITTAL: IT IS THE DISTANCE
BETWEEN THE TIP OF THE SACRUM AND THE
MIDPOINT OF THE BISPINOUS DIAMETRE. IT
MEASURES 5 CM.

24. ANATOMICAL OUTLET
1. TRANSVERSE ( INTERTUBEROUS ) : IT MEASURES
BETWEEN INNER SURFACE OF ISCHIAL
TUBEROCITY. IT MEASURES 11CM.
2. ANTERO – POSTERIOR : IT IS THE DISTANCE
BETWEEN THE LOWER BORDER OF SYMBYSIS
PUBIS TO THE TIP OF THE COCCYX. IT MEASURES
13 CM.
3. POSTERIOR SAGITTAL : IT IS THE DISTANCE
BETWEEN THE SACRO COCCYGEAL JOINT AND
THE MIDPOINT OF TRANSVERSE DIAMETRE OF
OUTLET. IT MEASURES 8.5 CM