ANATOMY OF THE FEMALE BONY PELVIS and FETAL SKULL by dr.shabnam naz

ANATOMY OF THE FEMALE BONY PELVIS and FETAL SKULL:

ANATOMY OF THE FEMALE BONY PELVIS and FETAL SKULL DR. SHABNAM NAZ MBBS, MCPS, FCPS ASSISTANT PROFESSOR OBGYN UNIT 1 SHAHEED MOHTARMA BENAZIR BHUTTO MEDICAL UNIVERSITY LARKANA

Anatomy of Pelvis:

Anatomy of Pelvis 2 Innominate bones ilium ischium pubis Sacrum Coccyx

Division of Pelvis:

Division of Pelvis False Pelvis True Pelvis Pelvic Brim Pelvic Cavity Pelvic Outlet

WHAT IS THE PELVIC BRIM? :

WHAT IS THE PELVIC BRIM? It is the inlet of the pelvis which divides the pelvic cavity into false & true pelvis It is formed by the sacral promontory, ala of the sacrum, arcuate line of the ilium , iliopubic eminence, pictineal line of the pubis, pubic crest & symphesis pubis The brim is oval in shape: Antroposterior diameter (true conjugate) 11.5 cm Transverse diameter ------ 13.5 cm

Slide 7:

Pelvic Inlet (pelvic brim)

The pelvic cavity:

The pelvic cavity The pelvic canal is curved , the post wall is longer than the anterior The most roomy zone with almost round shape TD---12 cm APD----12 cm

Slide 9:

Pelvic Cavity and Muscles of Pelvic Floor

THE PELVIC OUTLET:

THE PELVIC OUTLET Lower border of the symphysis pubis, ischial tuberosities & tip of the coccyx The subpubic arch has an angle of ---85°

Slide 11:

The Pelvic Outlet Antero-posterior (AP) diameters: 13.5 cm Transverse diameters: 11.5 cm Bituberous diameter = 11 cm Bispinous diameter = 10.5 cm

PELVIC WALLS :

PELVIC WALLS The inner aspect of the bony pelvis is covered with muscles Above the brim --- iliacus & psoas Sidewalls ---- obturator internus & its fascia Post wall ---- pyriformis Pelvic floor ---- lavator ani & coccygeus

Muscles of Pelvic Walls:

Muscles of Pelvic Walls

PELVIC LIGAMENTS:

PELVIC LIGAMENTS Sacrospinous ligament  lateralaspect of the sacrum to ischial spines Sacrotuberous ligament  lateral aspect of the sacrum to inner aspect of ischial tuberosity Sacroiliac ligament  medial surface of the ilium to sacrum lliolumbar ligament  iliac crest to transv lumbar vertebra

Diameters of Normal Pelvis:

Diameters of Normal Pelvis Smallest diameter in the pelvis is inter ischial spinous diameter. If interischial spinous diameter is 10 cms or more it rules out grossly contracted pelvis. Diameter of the Brim Anteroposterior = 11.5 cm Transverse = 13.5cm

Slide 17:

Diameter of the cavity Antero-posterior = 12cm Transverse = 12cm Diameter of the outlet Antero-posterior = 13.5cm Transverse = 11.5cm Interischial Tuberous diameter = 11cm

Slide 18:

Sex Differences of the Pelvis Subpubic angle: ♂: 55 o -58 o ♀ :80 o -100 o The sacrum is shorter, wider, and flatter in females than in males The ischial tuberosities are everted in females

Types of Pelvis:

Types of Pelvis Normal Pelvis Gynaecoid Android Anthropoid Platypelloid Contracted pelvis

Slide 21:

Varieties of the Female Pelvis Gynecoid pelvis Android pelvis: male ( funnel-shaped) Platypelloid pelvis: transverse diameters > AP diameters Anthropoid pelvis: All the AP diameters > transverse diameters. Contracted pelvis Asymmetrical pelvis

ADEQUACY OF THE PELVIS TO ACHIEVE VAGINAL DELIVERY:

ADEQUACY OF THE PELVIS TO ACHIEVE VAGINAL DELIVERY CLINICALLY FAVORABLE PELVIS. Sacral promontory can not be felt Ischial spines are not prominent Subpubic arch accept 2 fingers Intertuberous diameter accept 4 knuckles on pelvic exam

OBSTETRIC CONJUGATE :

OBSTETRIC CONJUGATE The shortest APD between sacral promontory & symphysis pubis Can only be measured radiologically N 11.5 cm

Slide 25:

TRUE CONJUGATE? APD between promontory of the sacrum & superior margin of the symphysis pubis (12 cm) DIAGONAL CONJUGATE? Distance between sacral promontory & inferior margin of the symphysis pubis Measured clinically (13.5cm)

Contracted Pelvis:

Contracted Pelvis Pelvis through which the head of normal size fetus (wt 3.5 kg) can’t pass or a pelvis with interschial spinous diameter is < 10 cm Types Absolute/Grossly contracted pelvis Due to acquired causes

Generally Contracted Pelvis:

Generally Contracted Pelvis Gynaecoid (43%) Android(33%) Anthropid (13%) Platypelloid (3%)

Due to Metabolic Disease:

Due to Metabolic Disease Ricketic Osteomalacic

Ricketic Pelvis:

Ricketic Pelvis Reduced A.P diameter Kidney shape Pelvis

Disease of Bones:

Disease of Bones Spine 1= Kyphosis 2= Scoliosis 3= Spondylolisthesis Pelvis 1= Tumours 2= Trauma Lower Limb 1=congenital Dislocation of Hip Joint 2=Tuberculosis of Hip Joint 3=Poliomyelitis of Lower Limb 4=Perthes Disease

Congenital deformities of Pelvis :

Congenital deformities of Pelvis Assimilation High (06 sacral vertebrae) Low (04 sacral vertebrae)

Naegle’s Pelvis (Defective development of ala of sacrum):

Naegle’s Pelvis (Defective development of ala of sacrum)

Robert Pelvis (Absence of ala of sacrum ) :

Robert Pelvis (Absence of ala of sacrum )

4> Split Pelvis Defective development of symphysis pubis :

4> Split Pelvis Defective development of symphysis pubis

Problems Encountered in Contracted Pelvis:

Problems Encountered in Contracted Pelvis Small Round Pelvis Extreme Flexion Excessive moulding Delay in 2 nd Stage Foetal distress Maternal distress Instrumental delivery BVD is hazardous Because of limited space for internal manipulations.

Small Android Pelvis:

Small Android Pelvis Delayed engagement Occipito posterior position because widest diameter lies in posterior segment of brim. Spontaneous delivery by moulding leading to perneal tears. D.T.A

Platypelloid Pelvis:

Platypelloid Pelvis Head fails to engage– but once engaged has no further problem

Diagnosis of contracted pelvis:

Diagnosis of contracted pelvis

HISTORY:

HISTORY Bone disease in childhood Traumatic injury to bone /limbs poliomyelitis

OBSTERICAL HISTORY:

OBSTERICAL HISTORY History of SVD one or two years back of 3.5 Kg baby rules out contracted pelvis. History of prolonged labour,difficult forceps delivery,cesarean section,still birth,maternal injuries and VVF. These are strongly suggestive and careful assessment.

GENERAL EXAMINATIONS:

GENERAL EXAMINATIONS Height If height is <5 feet ,CPD is suspected but it is not always necessary.

ANY Obvious Bony Deformity:

ANY Obvious Bony Deformity Kyphosis,Limping gait.

LOCAL EXAMINATION:

LOCAL EXAMINATION Abdominal Examination Previous scar. Nature of scar. Haphazard scar suggests wound infection and healing by second intention. Incisinal hernia.

PALPATION :

PALPATION PELVIC GRIP : Not engaged or engaged.

Internal Pelvimetry Clinical Pelvimetry (Vaginal Examinatio) :

Internal Pelvimetry Clinical Pelvimetry (Vaginal Examinatio ) Assessment of brim by “diagonal conjugate”

Assessment of cavity:

Assessment of cavity Sacral curve. Mobility of sacrococcygeal joint. Position of ischial spines. Palpation of sacrosciatic notches should accommodate 2 fingers. Pelvic side,convergent or divergent.

ASSESSMENT OF OUTLET:

ASSESSMENT OF OUTLET Subpubic arch. Sacrococcygeal junction is felt and AP diameter of outlet is assessed. Interischial tuberosity diameter ,accommodate 4 knuckles of the fist.

MUNRO KERR’S TEST:

MUNRO KERR’S TEST

Ideal obsteric pelvis:

Ideal obsteric pelvis

X RAY PELVIMETRY:

X RAY PELVIMETRY Only Value In. : Breech presentation an clinically borderline pelvis. : Elderly primigravida with vertex presentation and borderline pelvis. : Previous history of unexplained difficult deliveries.

Ultrasound:

Ultrasound Measurment of BPD but moulding in labour can reduce the diameter.

MANAGEMENT OF CONTRACTED PELVIS:

MANAGEMENT OF CONTRACTED PELVIS GROSSLY CONTRACTED : C-SECTION. BORDERLINE: SVD. Forceps/ Vacum . SECTION ,if failure of trial.

Slide 57:

Anatomy Of Fetal Skull

fetal skull:

fetal skull

Fetal Skull:

Fetal Skull The skull is formed of the face , the vault & the base The bones that form the skull are : two frontal bones, two parietal bones, two temporal bones wings of the sphenoid & occipital bone The bones of the face & base are heavy & fused The bones of the vault are 2 frontal ,2 parietal & occipital The bones of the vault are not joined thus changes in the shape of the fetal head during labor can occur due to molding

FETAL SKULL DEFINITIONS :

FETAL SKULL DEFINITIONS Bregma  Ant fontanelle Brow  lies between bregma &root of the nose Face  lies between root of the nose & suborbital ridges Occiput  boney prominence behind post fontanelle Vertex  diamond shaped area between ant & post fontanelles & parietal eminences

FETAL SKULL SUTURES:

FETAL SKULL SUTURES Frontal suture  between 2 frontal bones Sagittal suture  between 2 parietal bones Coronal suture  between parietal & frontal Lambdoid suture  between parietal & occipital Temporal suture  between inferior margin of the parietal & temporal

FETAL SKULL FONTANELLES :

FETAL SKULL FONTANELLES Anterior fontanelle  diamond shaped space between coronal & sagittal suture 3 * 3 cm , ossifies at 18 m Post font (lambda)  triangle shaped space between sagittal & lambdoid suture

FETAL SKULL DIAMETERS :

FETAL SKULL DIAMETERS Biparietal diameter 9.5 cm.  between parietal eminences The greatest transverse diameter Suboccipitobregmatic 9.5 cm.  middle of the bregma to undersurface of the occipital bone at the neck The presenting diameter of the well flexed head in labour Suboccipitofrontal 10.5 cm  root of the nose to undersurface of the occipital bone at the neck The presenting diameter of the partially flexed head

FETAL SKULL DIAMETERS:

FETAL SKULL DIAMETERS Occipitofrontal 11.5 cm  Root of the noose to the most prominent point of the occiput A defelexed head presents with this diameter Mentovertical 13 cm  Chin to most prominent point of the occiput The presenting diameter in brow presentation The largest diameter of the fetal head Submentobregmatic 9.5 cm  Chin to middle of bregma The presenting diameter in face presentation

MOULDING OF THE HEAD:

MOULDING OF THE HEAD Occurs with descent of the fetal head into the pelvis to reduce the head circumference Frontal bones slip under parietal bones Parietal bones override each other Parietal bones slip under the occipital bone

Degree of Moulding:

Degree of Moulding 0  suture lines are separate + 1  suture lines meet + 2  suture lines overlap but can be reduced by gentle digital pressure + 3  overlap irreducible

Moen Jo Daro Larkana Sindh:

Moen Jo Daro Larkana Sindh THANKS