the bony pelvis

Upload: victor-gabriel-rugina

Post on 03-Jun-2018

228 views

Category:

Documents


0 download

TRANSCRIPT

  • 8/12/2019 The Bony Pelvis

    1/26

    THE BONY PELVIS

    DR. AHMED ABDULWAHAB

    Assistant Professor,

    Consultant

    OBGYN Department

  • 8/12/2019 The Bony Pelvis

    2/26

    In women the pelvis has specialform that adapts to childbearing .

    It is composed of four bones .

    The sacrum coccyx and twoinnominate bones ..

    The innominate bone is formed bythe fusion of the ilium ,ischium, andpubis

  • 8/12/2019 The Bony Pelvis

    3/26

    The true pelvis is the portionimportant in childbearing , isbounded above by promontory andalae of the sacrum the lineaterminalis and the upper margin of

    the pubic bone , and below by thepelvic outlet .

    Ischial spines are of great obstetrical

    importance because it is the shortestpelvic diameter and has a valuablelandmarks in assessing the level of

    the presenting part of the fetus

  • 8/12/2019 The Bony Pelvis

    4/26

    The sacrum form the

    posterior wall of the pelvisand it is curved toaccommodate the rotating

    head .The promontory may be felt

    on vaginal examination andprovide a landmark forclinical pelvimetry

  • 8/12/2019 The Bony Pelvis

    5/26

  • 8/12/2019 The Bony Pelvis

    6/26

    Pelvic joints

    Symphysis pubis where pelvicbones are joined togetheranteriorly

    Sacroiliac joint where pelvic

    bones are joined

    posteriorly .

  • 8/12/2019 The Bony Pelvis

    7/26

    Planes and diameters of the

    pelvisFour imaginary planes

    1- the plane of pelvic inlet

    2-the plane of pelvic outlet

    3- the plane of mid pelvis

    4

    the plane of greatest

    pelvic dimensions

  • 8/12/2019 The Bony Pelvis

    8/26

    Pelvic shapes 1-gynecoid pelvis the inlet is

    slightly oval or rounded , theischial spines are not prominent ,the pubic arch is wide , sacrum is

    well curved .

    Android pelvis is a deep andconvergent with prominentischial spines , narrow sub-pubicarch and straight sacrum .

  • 8/12/2019 The Bony Pelvis

    9/26

    Pelvic inlet measurement

    Diagonal conjugate it is the distant

    from the sacral promontory to thelower margin of the symphysis pubis.

    True conjugate from sacral

    promontory to upper border ofsymphysis pubis

    Obstetric conjugate from sacral

    promontory to mid of posterior aspectof symphysis pubis subtract 1.5-2.0 cmfrom diagonal conjugate

  • 8/12/2019 The Bony Pelvis

    10/26

    The mid pelvis at the level

    of ischial spines the inter-spinous diameter is 10 cm .

    Pelvic outlet clinically it isthe distant between theischial tuberosities it isaround 8.0 cm

  • 8/12/2019 The Bony Pelvis

    11/26

    THE FETAL SKULL

    BONES

    Two frontal bones separated by frontalsuture.

    Two parietal bones separated by sagittalsuture .

    Two coronal sutures between frontal and

    parietal bones .

    Two lambdoid sutures between parietaland occipital bone .

  • 8/12/2019 The Bony Pelvis

    12/26

  • 8/12/2019 The Bony Pelvis

    13/26

    Sutures meet at an irregular space formswhich is enclosed by a membrane called

    fontanel . Anterior fontanel is a lozenge shape

    between the two frontal and two parietalbones usually it is opened .

    Posterior fontanel at the junction of thetwo parietal bones and occipital bone .

    It gives an important informationconcerning presentation and position of

    the fetus.

  • 8/12/2019 The Bony Pelvis

    14/26

    Fetal head diameters

    Subocipoto-bregmatic 9.5 cm vertexpresentation.

    Submento-bregmatic 9.5 cm facepresentation.

    Mento-vertical 12.5 browpresentation .

    Biparietal diameter 9.5cm .

    Occipto-frontal 10.5 cm

  • 8/12/2019 The Bony Pelvis

    15/26

    Occipital bone is the landmark invertex presentation.

    Mentum is landmark for face

    presentation, Frontal bone is land mark for brow

    presentation

  • 8/12/2019 The Bony Pelvis

    16/26

    labour

    Definition.

    It is the onset of painful, regular

    ,contractions, more than one every ten

    minutes. With progressive cervical

    effacement and dilatation

    accompanied by descend of the fetal

    presenting part.

  • 8/12/2019 The Bony Pelvis

    17/26

    Stages of labor

    Labor is divided in to three stages.

    1ststage from diagnosis of labor till fulldilatation of the cervix.

    2ndstage of labor from full dilatation ofthe cervix till delivery of the fetus.

    3rdstage from delivery of the fetusuntil delivery of the placenta.

  • 8/12/2019 The Bony Pelvis

    18/26

    The duration of labor

    Primigravida about 12 hours .

    Multigravida 8.0 hours

    The moral of most women deteriorateif labor is prolonged .

    There is greater incidence of fetal

    hypoxia after long labor.Greater incidence of operative vaginaldelivery.

  • 8/12/2019 The Bony Pelvis

    19/26

  • 8/12/2019 The Bony Pelvis

    20/26

    DESCENT.

    It is secondary to uterine action in 1stand early phase of 2ndstage of labor .

    FLEXION

    When the head descent to the narrowmid-cavity flexion should occur.

  • 8/12/2019 The Bony Pelvis

    21/26

    INTERNAL ROTATION .

    The shape of the bony pelvis and direction ofthe pelvic floor muscles in addition to thewell flexed head will help the head torotate the head into the occipito anterior

    position .

    In a well flexed head the occiput will meetthe pelvic floor and will guide the direction

    of the rotation

  • 8/12/2019 The Bony Pelvis

    22/26

    EXTENSION.

    The head is deliver by extension firstthe bregma ,face , and chin appear insuccession over the posterior vaginalopening and perineal body.

    RESTITUTION.

    As soon as the head escape from thevulva the head aligns itself with theshoulder

  • 8/12/2019 The Bony Pelvis

    23/26

    EXTERNAL ROTATION.

    In order to deliver the shoulders haveto rotate into the direct anterior-posterior plane .

    The doctor will rotate the head makingthe face of the fetus looking tomedial aspect of the maternal thigh .

  • 8/12/2019 The Bony Pelvis

    24/26

    Delivery of the shoulders .

    The anterior shoulder is under thesymphysis pubis and deliver first

    ,and the posterior shoulder deliver

    subsequently

  • 8/12/2019 The Bony Pelvis

    25/26

    THIRD STAGE OF LABOR .

    Separation of the placenta

    occurs because of the

    reduction of the volume of the

    uterus due to the uterine

    contraction and retraction

  • 8/12/2019 The Bony Pelvis

    26/26