<P> The secondary centers generally appear at the epiphysis . Secondary ossification mostly occurs after birth ( except for distal femur and proximal tibia which occurs during 9th month of fetal development ) . The epiphyseal arteries and osteogenic cells invade the epiphysis , depositing osteoblasts and osteoclasts which erode the cartilage and build bone . This occurs at both ends of long bones but only one end of digits and ribs . </P>
when do secondary ossification centers appear in the epiphysis
after birth 9th month of fetal development