Clinical Anatomy of Bony Pelvis

Question 1

features of bony pelvis?

Answer 1

2 hip bones
- ilium
- ischium
- pubis
sacrum
coccyx

Question 2

features of the ilium?

Answer 2

look like elephant ears
iliac crest
ASIS
PSIS
iliac fossa

Question 3

features of the ischium?

Answer 3

ischiopubic ramus (below the hole)
ischial spine
ischial tuberosity (lower posterior lump)

Question 4

features of pubis?

Answer 4

superior pubic ramus (above the hole)
pubic tubercle (lump near the join in the middle)
pubic arch (the join)
sub-pubic angle (angle underneath join)

Question 5

what are the bony features of the pelvic inlet?

Answer 5

sacral promontory
ilium
superior pubic ramus
pubic symphysis

Question 6

bony features of pelvic outlet?

Answer 6

pubic symphysis 
ischiopubic ramus
ischial tuberosities 
sacrotuberous ligaments 
coccyx

Question 7

where is the pelvic cavity located?

Answer 7

continuous with abdominal cavity

lies between pelvic inlet and pelvic floor

Question 8

where does the inguinal ligament attach between?

Answer 8

ASIS and pubic tubercle

Question 9

what is the name of the hole between the superior pubic ramus and ischiopubic ramus?

Answer 9

obturator foramen

Question 10

what are the main joints of the pelvis?

Answer 10

sacroiliac joint
hip joint (synovial)
pubic symphysis (secondary cartilaginous)

Question 11

where is the sacrotuberous ligament?

Answer 11

between sacrum and ischial tuberosity

Question 12

where is the sacrospinous ligament?

Answer 12

between sacrum and ischial spine

Question 13

what are the main functions of sacrotuberous and sacrospinous ligaments?

Answer 13

ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebral column (e.g when jumping or late pregnancy)

Question 14

the presence of the sacrotuberous and sacrospinous ligaments create which 2 foraminae?

Answer 14

the greater and lesser sciatic foraminae

• sacrotuberous forms posterior wall
• • sacrospinous splits into upper and lower holes

Question 15

what passes through the obturator foramen?

Answer 15

obturator membrane obturator nerve and vessels pass via obturator canal

Question 16

what muscle does the obturator canal pass through?

Answer 16

obturator internus

Question 17

what vessels are at risk in a pelvic trauma and may cause a haemorrhage?

Answer 17

common iliac artery
internal/external iliacs and branches
common iliac vein
sacral plexus

Question 18

what are the main differences between male and female pelvis?

Answer 18

female

• more shallow (height wise)
• wider antero-posteriorly and transversely
• more flexible ligaments
• wider sub-pubic angle
• bigger inlet/outlet
• much larger sciatic notch

Question 19

features of foetal skull?

Answer 19

sagittal suture
coronal suture
lambdoid suture (between parietal and occipital bones)
anterior fontanelle (large)
posterior fontanelle

Question 20

what is moulding in foetal skull?

Answer 20

movement of one bone over another to allow the foetal head to pass through the pelvis during labour
sutures and fontanelles allow this

Question 21

what is the vertex in foetal skull?

Answer 21

area of the foetal skull

outlined by the anterior and posterior fontanelles and parietal eminences

Question 22

2 diameters measured in foetal skull?

Answer 22

occipitofrontal (longer)

biparietal (shorter)

Question 23

how does the foetus enter the pelvic cavity and why?

Answer 23

should enter facing either right or left

because pelvic inlet is wider transversely then AP and foetal skull is wider occipitofrontally then biparietally

Question 24

what does the “station” refer to in childbirth?

Answer 24

the distance of the foetal head from the ischial spines
-ve number = head is superior to the spines
+ve number = head is inferior to spines

Question 25

foetal head should be in what position as it descends through pelvic cavity?

Answer 25

rotate as it passes through

flexed with chin on chest

Question 26

how should the foetal head leave the pelvic outlet?

Answer 26

occipitoanterior position
extension of head on neck
(at the pelvic outlet, AP diameter is wider than transverse diameter)