Sacro-Iliac Joint

Question 1

What joint classifications are present at the sacro-iliac joint?

Answer 1

• synovial plane (diarthrosis arthrodia)

- fibrous (amphiarthrosis syndesmosis)

Question 2

What is the name of the articular surface of the sacrum at the sacro-iliac joint?

Answer 2

the auricular surface of the sacrum

Question 3

What is the name of the articular surface of the ilium at the sacro-iliac joint?

Answer 3

the auricular surface of the ilium

Question 4

What is the auricular surface of sacrum composed of?

Answer 4

true articular cartilage, a modification of hyaline cartilage

Question 5

What is the auricular surface of the ilium composed of?

Answer 5

articular cartilage, interspersed with fibrocartilage

Question 6

What is the superficial appearance of the auricular surfaces of the sacro-iliac joint in infancy?

Answer 6

both the sacrum and ilium are smooth surfaced at the sacro-iliac joint

Question 7

What is the superficial appearance of the auricular surfaces of the sacro-iliac joint by age 15?

Answer 7

the sacrum develops a sacral groove while the ilium develops an iliac ridge

Question 8

Which gender is biased with greater unevenness of the auricular surface of the sacro-iliac joint?

Answer 8

males

Question 9

What additional modifications of the auricular surfaces of the sacro-iliac joint may occur?

Answer 9

posterior to the sacral groove and iliac ridge, an iliac tuberosity and sacral fossa appear

Question 10

What forms the accessory sacro-iliac joint?

Answer 10

the sacral tuberosity and the iliac sulcus

Question 11

What pathological or age-related modifications of the sacro-iliac joint may occur?

Answer 11

degenerative arthrosis and ankylosis

Question 12

What does degenerative arthrosis mean?

Answer 12

a condition of degeneration of the joint, sometimes referred to as degenerative joint disease (DJD)

Question 13

What does ankylosis mean?

Answer 13

a condition of fibrous adhesion occurs within the joint

Question 14

What is the age and surface bias associated with degenerative arthrosis of the sacro-iliac joint?

Answer 14

age 40, the iliac auricular surface

Question 15

What is the age and gender bias associated with ankylosis of the sacro-iliac joint?

Answer 15

age 50 and male bias, particularly in African American males

Question 16

What is the function of the sacro-iliac joint?

Answer 16

it transfers weight from the vertebral column onto the pelvic girdle and lower extremity

Question 17

What movements at the sacro-iliac joint are described as forward nodding and backward nodding?

Answer 17

nutation and counternutation, respectively

Question 18

Which part of the sacro-iliac joint is in motion during nutation and counternutation?

Answer 18

the ilium or pelvis in general

Question 19

What are the attachment sites of the capsular lig of the sacro-iliac joint?

Answer 19

at the margins of the auricular surfaces of the sacrum and ilium

Question 20

What is unusual about the capsular lig of the sacro-iliac joint?

Answer 20

it appears to be absent on the posterior margin of the sacro-iliac joint

Question 21

What are the accessory ligs of the sacro-iliac joint?

Answer 21

• anterior sacro-iliac lig
• interosseous sacro-iliac lig
• posterior sacro-iliac lig

Question 22

What joint classification is associated with the accessory ligs of the sacro-iliac joint?

Answer 22

fibrous (amphiarthrosis) syndesmosis

Question 23

What is unusual about the anterior sacro-iliac lig?

Answer 23

it appears to be a condensation or thickening of the fibrous capsule of the sacro-iliac joint

Question 24

What are the attachment sites of the anterior sacro-iliac joint?

Answer 24

at the anterior and inferior margins of the capsular lig

Question 25

At what location is the anterior sacroiliac lig best developed?

Answer 25

along the arcuate line and posterior inferior iliac spine (PSIS) of the ilium

Question 26

What is the age and gender bias associated with ossification of the anterior sacro-iliac lig?

Answer 26

age 40 and male bias

Question 27

Which is the strongest of the sacro-iliac lig?

Answer 27

the interosseous sacro-iliac lig

Question 28

What are the attachment sites of the interosseous sacroiliac lig?

Answer 28

at the sacral tuberosity and the iliac sulcus

Question 29

What is the relationship between the capsular and interosseous sacroiliac lig?

Answer 29

the interosseous sacroiliac lig replaces the capsular lig posteriorly

Question 30

What passes between the layers of the interosseous sacroiiac lig?

Answer 30

dorsal rami from the sacral spinal nerves

Question 31

What are the attachment sites of the posterior sacroiliac lig?

Answer 31

from the intermediate sacral crest and lateral sacral crest to the posterior superior iliac spine (PSIS) and the posterior medial margin of the iliac crest

Question 32

What are the subdivisions of the posterior sacroiliac lig?

Answer 32

the short posterior sacroiliac lig and the long posterior sacroiliac lig

Question 33

What are the attachment sites of the short posterior sacroiliac lig?

Answer 33

from the intermediate sacral crest at S1 and lateral sacral crest at S2 to the posterior superior iliac spine (PSIS) and the posterior medial margin of the iliac crest

Question 34

What are the attachment sites of the long posterior sacroiliac lig?

Answer 34

from the lateral sacral crest at S3 and S4 to the PSIS

Question 35

What lig blends with the lateral border of the long posterior sacroiliac lig?

Answer 35

the sacrotuberous lig