Lecture 2 Os Coxae

Question 1

what is the acetabulum ?

Answer 1

the fossa in the ossa coxae where the head of the femur sits.

Question 2

What is the pulvinar

Answer 2

fibrofatty cushioning in the acetabulum.

Question 3

what three bones merge in the centre of the acetabulum

Answer 3

the ilium the ischium and the pubis

Question 4

how many primary ossification centres are there and where are they located

Answer 4

there’s 3, one on each bone.

Question 5

The syncohndrosis can cause pain in childhood, if it becomes inflammed when does this pain subside?

Answer 5

When the bones fuse

Question 6

Name some of the different shapes the pelvic inlet can be

Answer 6

android- most common
gynecoid
anthropoid

Question 7

What causes the condition Naegele pelvis

Answer 7

Missing sacral wing- asymmetrical pelvis

Question 8

why must an infant rotate in child birth

Answer 8

because the dimensions of the pelvic inlet and outlet are opposites

Question 9

what two ligaments divide the greater and lesser sciatic foramina ?

Answer 9

the sacrospinous ligament and the Sacro tuberous ligament

Question 10

what boney landmark divides the greater and lesser sciatic foramen

Answer 10

the ischial spine

Question 11

which of the ligaments connecting the femur and pelvis is commonly torn in car crashes when the passengers knees hit the dashboard

Answer 11

othe ischiofemural ligament. its the weakest of the 3 and is located posteriorly

Question 12

what ligaments form the joint capsule of the hip

Answer 12

the iliofemoral, ischiofemoral and pubofemoral

Question 13

what is the blood supply to the head of the femur

Answer 13

the retinacular arteries , from the lateral and medial circumflex arteries from the profunda femoris artery and a small contribution from the obturator artery but not enough to keep the head alive.

Question 14

what are two types of femoral fracture

Answer 14

pertrochanteric and subcapital- subcapital leads to death of the head of the femur due to loss of blood supply.

Question 15

what is the normal angle for the neck of the femur

Answer 15

125 degrees

160 in children

Question 16

what is the medicolegal significance of the ossification center on the distal femur

Answer 16

it appears at the 9th month of fetal life so is a sign of fetal maturity

Question 17

what is the physical function of the patella

Answer 17

to increase the distance traveled by the quadriceps tendon to reduce the force needed for movement— movement= F X D

Question 18

what is the Q angle

Answer 18

the angle between the line connecting the knee and tibial tuberosity and the line connecting the knee and anterior superior iliac spine- its larger in women (14 Vs. 17 degrees)

Question 19

what is the disadvantage of a greater Q angle

Answer 19

More likely to dislocate the patella

Question 20

what two features other then the q angle predispose someone to dislocation of the patella

Answer 20

weak knee capsule or underdeveloped lateral condyle

Question 21

what is Nelaton’s line and what is its function

Answer 21

a line connecting the ant. sup. iliac spine and the ischial tuberosity. In normal condition the greater trochanter should be below this line, if its not the femur may be broken

Question 22

what is Bryant’s triangle

Answer 22

its formed by lines between the greater trochanter the ant. sup. iliac spine and the the vertical line from there. it can be used to compare left and right sides to check for femoral shortening.