The Pelvic Girdle

Question 1

Pelvic Girdle =

Answer 1

Hip bone + Hip bone

Question 2

At what points do the hip joints fuse to form the pelvic girdle?

Answer 2

To each other at the pubic symphysis

To the vertebral column at the sacroiliac joints

Question 3

Functions of pelvic girdle

Answer 3

• Connects the axial skeleton to the lower limbs
• Supports and protects the lower abdominal and pelvic organs
• Provides attachment for a number of muscles and ligaments used in locomotion.

Question 4

What are the bones that make up the pelvic girdle?

Answer 4

Two hip bones
Sacrum
Coccyx

Question 5

How many articulations are there within the pelvis?

Answer 5

4

Question 6

What are the articulations at the pelvic girdle?

Answer 6

Sacroiliac joints (x2)
Sacrococcygeal symphysis
Pubic symphysis

Question 7

The osteology of the pelvic girdle allows the pelvic region to be divided into:

Answer 7

Two.

Greater (false) pelvis
Lesser (true) pelvis

Question 8

Greater pelvis (false pelvis)

Answer 8

• Located superiorly
• Provides support of the lower abdominal viscera (such as the ileum and sigmoid colon)
• Little obstetric relevance

Question 9

Lesser pelvis (true pelvis)

Answer 9

• Located inferiorly

- Within the lesser pelvis reside the pelvic cavity and pelvic viscera.

Question 10

The junction between the greater and lesser pelvis is known as…

Answer 10

…the pelvic inlet.

Question 11

The outer bony edges of the pelvic inlet are called…

Answer 11

…the pelvic brim

Question 12

The borders of the pelvic inlet:

Answer 12

Posterior - Sacral promontory (the superior portion of the sacrum) and sacral wings (ala)

Lateral – Arcuate line on the inner surface of the ilium, and the pectineal line on the superior pubic ramus

Anterior – Pubic symphysis.

Question 13

Linea Terminalis

Answer 13

The combined pectineal line, arcuate line and sacral promontory

Question 14

Iliopectineal line

Answer 14

The combined arcuate and pectineal lines. This represents the lateral border of the pelvic inlet.

Question 15

The borders of the pelvic outlet

Answer 15

Posterior - The tip of the coccyx

Lateral - The ischial tuberosities and the inferior margin of the sacrotuberous ligament

Anterior - The pubic arch (the inferior border of the ischiopubic rami).

Question 16

The angle beneath the pubic arch is known as…

Answer 16

…the sub-pubic angle

Question 17

The female pelvis is described as:

Answer 17

…gynaecoid

Question 18

The male pelvis is described as:

Answer 18

…android

Question 19

When comparing the two pelvises, the gynaecoid pelvis has:

Answer 19

• Wider and broader structure
• Lighter weight
• An oval-shaped inlet
• Less prominent ischial spines
• A greater angled sub-pubic arch, more than 80-90 degrees.
• Shorter, more curved sacrum with a less pronounced sacral promontory.

Question 20

Shape of pelvic inlet in android pelvis

Answer 20

Heart-shaped

Question 21

Why is the ischial spine shorter in the gynaecoid pelvis?

Answer 21

To allow for a greater bispinous diameter

Question 22

What is the diagonal conjugate of the pelvis?

Answer 22

The diagonal conjugate is the distance between the inferior border of the pubic symphysis and the sacral promontory. It is ~12cm in women

Question 23

What is the obstetric or true conjugate of the pelvis?

Answer 23

This distance between the sacral promontory and the midpoint of the pubic symphysis (where the pubic bone is thickest), estimated at ~11cm, ~1.5cm less than the diagonal conjugate.

Question 24

What is the transverse diameter of the pelvic inlet in women?

Answer 24

~13cm

Question 25

What is the transverse diameter of the pelvic outlet in women?

Answer 25

~11cm

Question 26

What is the widest distance of the pelvic inlet?

Answer 26

The transverse diameter

Question 27

What is the oblique diameter of the gynaecoid pelvis?

Answer 27

~12.5cm

Question 28

What is the anteroposterior diameter of the pelvic outlet?

Answer 28

~9.5cm to 11.5cm

Question 29

The pelvic bones articulate with the axial skeleton via...

Answer 29

...the sacrum

Question 30

The hip bones are also known as...

Answer 30

Pelvic or coxal bones

Question 31

What is the primary function of the pelvic girdle?

Answer 31

Weight bearing and transfer to the lower limbs

Question 32

What are the primary joints of the pelvic girdle?

Answer 32

Sacroiliac Joint | Pubic symphysis

Question 33

Secondary joints of the pelvic girdle

Answer 33

- Lumbo-sacral joint | - Sacrococcygeal joints

Question 34

The sacroiliac joint is a compound joint made up of:

Answer 34

a. Anterior synovial joint | b. Posterior syndesmosis b/w tuberosities of bone

Question 35

What produces the interlocking of the bones of the synovial sacroiliac joint?

Answer 35

The articular surface of synovial joint has irregular elevations and depressions

Question 36

There is limited mobility in the sacroiliac joint. True or false?

Answer 36

True. Limited mobility is allowed because of weight transfer.

Question 37

Both sacroiliac joints move together as...

Answer 37

...a single unit and are considered bicondylar joints.

Question 38

The sacroiliac joints are covered by...

Answer 38

...two types of cartilage: - Sacral surface - hyaline cartilage - Ilial surface - fibrocartilage

Question 39

Dislocations of the sacroiliac joints are rare. True or false?

Answer 39

True!

Question 40

What are the ligaments of the sacroiliac joints?

Answer 40

1. Anterior sacroiliac ligament 2. Posterior sacroiliac ligament 3. Interroseous sacroiliac ligament 4. Sacrospinous ligament 5. Sacrotuberous ligament

Question 41

The anterior sacroiliac ligament is a thick and strong ligament. True or false?

Answer 41

False. It is a weak and thin ligament.

Question 42

The fibres of the posterior sacroiliac ligament are divided into

Answer 42

short (intrinsic)- horizontal, in upper part long (extrinsic) – oblique, in lower part -Strong ligament uniting the sacrum and ilium -Consists of series of: •Long fibres - run in an oblique vertical direction •Short fibres - run perpendicular from behind the articular surfaces of the sacrum to the ilium functions to keep the sacroiliac joint from distracting or opening.

Question 43

Which fibre of the posterior sacroiliac joint is horizontal and in upper part?

Answer 43

(extrinsic) – oblique, in lower part

Question 44

Which fibre of the posterior sacroiliac joint is oblique and in the lower part?

Answer 44

Long (extrinsic)

Question 45

Function of the posterior sacroiliac ligament?

Answer 45

It keeps the sacroiliac joint from distracting or opening.

Question 46

Which ligament is often stronger than bone such that a pelvic fracture occurs before it is torn?

Answer 46

The interroseous sacroiliac ligament

Question 47

The interroseous sacroiliac ligament lies...

Answer 47

... deep to posterior ligament

Question 48

What are the extrinsic sacroiliac ligaments?

Answer 48

- Sacrospinous | - Sacrotuberous

Question 49

Which ligament transforms the sciatic notch to the sciatic foramen?

Answer 49

Sacrotuberous ligament

Question 50

The sacrotuberous ligament joins...

Answer 50

fibres of the posterior ligament inferiorly

Question 51

The sacrotuberous ligament extends from...

Answer 51

...the posterior margin of the ilium to base of coccyx

Question 52

Causes of sacroiliac joint dysfunction

Answer 52

* Traumatic - Fall * Biomechanical - Leg length discrepancy * Hormonal * Inflammatory joint disease

Question 53

The interpubic disc of the pubic symphysis is wider in

Answer 53

...females

Question 54

The pubic symphysis is made up of...

Answer 54

fibrocartilaginous interpubic disc and surrounding ligaments

Question 55

Secondary cartilaginous joints in the pelvis

Answer 55

Pubic symphysis | Sacrococcygeal joint

Question 56

Ligaments of the pubic symphysis are thickened to form...

Answer 56

- Superior pubic lig. - Inferior pubic lig - Anterior pubic lig - Posterior pubic lig

Question 57

The lumbosacral joint is made up of 2 joints...

Answer 57

- Intervertebral b/w L5/S1 (anterior) | - Zygapophyseal b/w articular processes

Question 58

The lumbosacral joint is strengthened by...

Answer 58

...iliolumbar ligament

Question 59

The sacrococcygeal joint is made up of...

Answer 59

...fibrocartilage and ligaments joining the apex of sacrum to base of coccyx

Question 60

The erect pelvis is inclined to what angle?

Answer 60

80 degrees

Question 61

Boundaries of the greater pelvis

Answer 61

Anterior - Anterior abdominal wall Posterior - L5, S1 vertebrae Postero-lateral - Iliac fossa

Question 62

The lesser pelvis is limited inferior by...

Answer 62

...the musculofascial pelvic diaphragm