Secondary ossification center for lower end of femur?

Secondary center of lower end of femur appears at 9th month of intrauterine life (present at bih). Ossification of femur The femur ossifies from one primary and four secondary centres. The primary appear, one for the lower end at the end of the ninth month of intrauterine life, one for the head during the first six months of life, one for the greater trochanter during the fouh year, and one for the lesser trochanter during the twelfth year. There are three epiphyses at the upper end and one epiphysis at the lower end. The upper epiphyses; lesser trochanter, greater trochanter and head, in that order, fuse with the shaft at about eighteen years. The lower epiphysis fuses by the twentieth year. Ref ; Narayana reddy 33rd ed.