infant hip joint

Question 1

bones, connective tissues and muscles originate from

Answer 1

mesoderm

Question 2

hip bone composed of 3

Answer 2

ilium, ischium and pubis

Question 3

acetabulum has the

Answer 3

triradiate cartilage
located at lateral aspects
articulation point for femoral head

Question 4

At the rim of the acetabulum sits a lip of cartilage called

Answer 4

acetabular labrum

Question 5

femoral head is ______ at birth

Answer 5

cartilaginous

Question 6

femoral head begins to ossify at

Answer 6

2 to 8 months from the centre outwards

Question 7

_____ contribute to the laxity of the fetal ligaments

Answer 7

maternal hormones

Question 8

laxity of fetal ligaments may cause

Answer 8

create vulnerable atmosphere for the hip to become subluxable or dislocatable

Question 9

developmental dysplasia of the hip occurs most freq when

Answer 9

at birth

sometimes happen during infancy

Question 10

the cause of DDH may be mechanical as a result of

Answer 10

positional influences in utero and after birth

Question 11

The cause of DDH may be physiological as a result of

Answer 11

resulting from a response to maternal hormones in utero

Question 12

risk factors of DDH

Answer 12

Born in breech position
Positive family Hx
Living in cultures that swaddle infants in extension and hip adduction
Oligohydramnios
Metatarsus adductus (img) and torticollis associated with DDH
Firstborn, female, white, high birth weight, native North American

Question 13

3 things done during clinical assessment of both hips

Answer 13

barlow maneuver
Ortolani maneuver
Visual assessment

Question 14

do instabilities of hip need treatment

Answer 14

some but most become normal without treatment

Question 15

significant dysplasia leads to

Answer 15

to disability / hip replacement surgeries in adulthood

Question 16

explain barlow test

Answer 16

Provocative test, determines if hip can be dislocated
The examiner attempts to push the femoral head posteriorly out of socket
Gentle adduction and push on the knee

Question 17

describe ortolani test

Answer 17

The examiner attempts to reduce/relocate a recently dislocated hip
Gentle out** and up*** movement

If positive both tests produce a sensation of clunk**

Question 18

what is positive allis or galeazzi sign

Answer 18

Relative shorteness of the femur with the hip and knees flexed
Discrepancy in leg lengths
Asymmetry of gluteal and thigh folds

Question 19

allis or galeazzi sign are only useful when

Answer 19

for unilateral DDH

Question 20

transducer freq for birth to 3 mo and older infants

Answer 20

12-7.5 MHz for birth to 3 mo

5.0 MHz for older infants

Question 21

Sonography of the hip is best performed up to

Answer 21

6 months

Question 22

what planes are used in hip scan

Answer 22

Coronal plane without stress

Transverse plane with and without stress maneuvers

Question 23

what is seen coronal scan plane

Answer 23

The femoral head can be identified sitting in the acetabulum

Iliac line will be identified superiorly, and the bony shaft of the femoral neck will be identified inferiorly

Iliac line should appear as a straight line - important in making an accurate assessment

Question 24

how to obtain the alpha and beta angles in the coronal plane

Answer 24

The first line is aligned with the ilium and extends through the head of the femur
The second line is drawn along the bony acetabulum
The third line extends from end of ilium line along the cartilaginous acetabulum (labrum)
The α-angle is formed between the 1st and 2nd line
The β-angle is formed between the 1st and 3rd line

Question 25

what is a normal alpha angle

Answer 25

more than or equal to 60 degrees

Question 26

normal beta angle

Answer 26

less than 55

big beta bad

Question 27

what are these angles compared to for diagnosis

Answer 27

graft classification

Question 28

4 classifications on GRAFF

Answer 28

type 1: normal alpha more than 60
type 2: normal up to 3 mo, angle 44-60
type 3: dislocated hip, angle less than 43
type 4: gross dislocation, angle not measurable

Question 29

what is femoral head coverage and what plane is it obtained in

Answer 29

Shows how well femoral head is contained in the acetabulum and whether or not the femoral head is in contact with the acetabular floor
coronal plane

Question 30

normal femoral head coverage

Answer 30

60%

Question 31

Hip instability (subluxation) will present with a FHC of approx

Answer 31

36-37%

Question 32

whats more reproducible FCH or alpha angle

Answer 32

alpha angle

Question 33

what is the classic normal appearance sign of the hip

Answer 33

ball on spoon
ball: femoral head
iliac line: handle
scoop: acetabulum