Part 14: Osteology of LL

Question 1

Describe the ossification of the hip bone

Answer 1

Develops in cartilage from 3 centres
Ilium (weightbearing) - 2nd month
Ischium - 3rd month
Pubis - 4th Month

Ischio and pubic rami fuse around 7 years
Y-shaped catilage begins to ossify around 12 years with 2-3 centres, closes around 15 years
At same time tiny bony centres arise in peripheral cartilage and fuse around 25 years

Question 2

Which are the growing ends of LL?

Answer 2

Knee ends

Question 3

Describe the ossification of the femur

Answer 3

Whole femur ossifies in cartilage from centre in shaft around week 8
Centre for lower end begins around birth - this is growing end of bone and fuses around age 20
centre appears in head around 1 year, GT 3 years and LT 12 years. Upper epiphysis fuses around 18 years

Question 4

Describe the ossification of the patella

Answer 4

Forms in hyaline cartilage at about 3 and completed in puberty

Question 5

Describe the ossification of the tibia

Answer 5

Ossifies in primary centre around week 8. Upper epiphysis shows centre around birth - this is growing end. Joins shaft about 20. Secondary tuberosity centre may appear in puberty.
Lower epiphysis ossifies in 2nd year and joins shaft about 18

Question 6

Describe the ossification of the fibula

Answer 6

Ossifies from central centre week 8.
Epiphysis at each end, head (growing end) is seen at 4 years and fuses at 20 years.
Lower end is seen at 2 years and fuses at 18 years

Question 7

Describe the ossificatio of foot bones

Answer 7

All ossify in cartilage
3 bones of tarsus are ossified at birth (talus, calcaneus and cuboid)
Navicular ossifies in 4th year
Cuneiforms ossify 1st-4th years
MT and phalangeals ossify shaft centres in utero -> further centres at age 5 -> fuse at 18 years