lecture 5 hip arthrology

Question 1

Where is the femoral head?

Answer 1

located just inferior to mid 1/3 of inguinal lig

Question 2

What is the shape of the femoral head?

Answer 2

2/3 of nearly perfect sphere

Question 3

What is posterior to the center of the femoral head?

Answer 3

the fovea

Question 4

What is the femoral head covered in (except fovea)?

Answer 4

articular cartilage

Question 5

What is the ligamentum teres?

Answer 5

tubular, synovial-lined connective tissue housing acetabular artery, contains mechanoreceptors

Question 6

Where ligamentum teres run?

Answer 6

Transverse acetabular ligament to fovea

Question 7

What is the acetabulum?

Answer 7

deep, cuplike socket

Question 8

What is the acetabular notch?

Answer 8

60-70 degree opening

Question 9

What is the acetabular fossa?

Answer 9

floor of fossa, no cartilage, no contact, filled with fat/blood vessels/synovial membrane/lig

Question 10

Where does the femoral head contact?

Answer 10

the lunate surface - covered in articular cartilage thickest along sup-ant region matching area of highest joint force with walking

Question 11

When does the acetabulum notch widen, lunate deform, contact increase in area/ and pressure decrease during gait?

Answer 11

Midstance

Question 12

How much does the area of the joint increase from the lunate surface during swing phase to the midstance phase?

Answer 12

20% during swing phase to 90% during mid stance phase

Question 13

What is the acetabular labrum?

Answer 13

strong, flexible ring of fibrocartilage on the rim of the acetabulum

Question 14

What lig spans the acetabular notch?

Answer 14

transverse acetabular lig

Question 15

What blends with articular cartilage of the acetabulum - labro-chondral junction?

Answer 15

internal labrum

Question 16

What does the acebtabular labrum do?

Answer 16

Provides mechanical stability “grip” and deepens socket

Question 17

What does the “seal” of the acetabuluar labrum do?

Answer 17

keeps negative pressure, fluid sealed (reduced friction/contact stress and improved lubrication to joint)

Question 18

What is the innervation and vascularization of the acetabular labrum?

Answer 18

poorly vascularized but well innervated (pain and proprioception)

Question 19

What is dysplastic acetabulum?

Answer 19

malformed, does not fully cover the femoral head
- chronic dislocation/OA/Pain

Question 20

What is the center edge CE? (defines dysplastic acetabulum)

Answer 20

degree acetabulum covers femoral head

Question 21

What is the acetabular anteversion angle?

Answer 21

the extent to which it faces anteriorly
- NLs is 20 degrees

Question 22

What is femoral version?

Answer 22

(ante/retro) defined as the angular difference between the axis of the femoral neck and transcondylar axis of the knee (craig’s test)

Question 23

What is acetabular anteversion?

Answer 23

A measurement used on cross-sectional imaging especially pelvic CT for the assessment of acetabular morphology

Question 24

What is femoral torsion?

Answer 24

the relative rotation between the bone’s shaft and neck

Question 25

What is normal femoral torsion?

Answer 25

15 degrees

Question 26

What is excessive anteversion?

Answer 26

> 15 degrees

Question 27

What is infant torsion?

Answer 27

infant 40 degrees anteversion - derotates to 15 deg by 16 yo

Question 28

What is excessive anteversion known to cause?

Answer 28

hip dislocation/OA/increase contact stress "in-toeing"

Question 29

What do the iliofemoral/pubofemoral/ischiofemoral ligs do?

Answer 29

reinforce ext capsule, iliocapsularis, glut min and rectus femoris

Question 30

What does the iiofemoral lig? What does it do?

Answer 30

thick, strong, upside down Y med and lat AIIS/rim of the acetabulum to the intertrochanteric line; full hip ext and full ER elongates it

Question 31

When is the pubofemoral lig taut?

Answer 31

taut in hip abd/ext and a bit of ER

Question 32

When is the ischiofemoral lig taut?

Answer 32

Taut in IR and abd

Question 33

What is the closed packed position of the hip?

Answer 33

the greatest simultaneous stretch to many structures - full ext, slight IR and abd

Question 34

What is femoral-on-pelvis osteokinematics?

Answer 34

femur about a fixed pelvis

Question 35

What is pelvis on femoral osteokinematics?

Answer 35

rotation of the pelvis over fixed femurs

Question 36

What are sagittal plane femoral on pelvis motions?

Answer 36

- hip flex 120-140 deg - with LE extended 70-80 degrees - hip ext 18-30 degrees

Question 37

What are frontal plane femoral on pelvis motions?

Answer 37

- abd/add - abd limited by pubofemoral and adductor muscles - add limited by abd/piriformis/ITB

Question 38

What are transverse plane femoral on pelvis movements?

Answer 38

IR and ER

Question 39

What are the 2 types of lumbopelvic rhythm?

Answer 39

- ipsidirectional - contradirectional

Question 40

What is ipsilateral lumbopelvic rhythm?

Answer 40

lumbar spine and pelvis move in tthe same direction, maximizes angular displacement of the entire trunk

Question 41

What is contradirectional lumbopelvic rhythm?

Answer 41

lumbar spine and pelvis move in opposite direcitons. supralumbar can stay nearly stationary, used in walking where head and eyes need to be still - lumbar spine is a decoupler

Question 42

What is sagittal plane contradirectional lumbopelvic rhythm?

Answer 42

- hip flx, ant tilt, lumbar spine, ext - hip ext, post tilt, spine flx

Question 43

What are some frontal plane contradirectional lumbosacral rhythm?

Answer 43

- abd of support hip/opp iliac crest hikes/ opposite side spine lateral flx - add opposite

Question 44

What is pelvis-on-femoral IR of the hip?

Answer 44

nonsupport LE side rotates forward - spine twists opposite

Question 45

What is pelvis-on-femoral ER of the hip?

Answer 45

nonsupport LE side rotates backwards - spine twists opposoite

Question 46

What are the arthrokinematics of NWB/open chain in the hip?

Answer 46

F: roll ant/slide post & inf E: roll post/slide ant & sup IR: roll ante/slide post ER: roll post/slide ant ABD: roll sup/slides inf ADD: roll inf/slide sup