Normally developing bone. In young growing horses, skeletal bones initially develop from cartilage, which is gradually converted into hard bone through endochondral ossification. During maturation, two growth plates develop at each end of the long bones. During endochondral ossification, special cartilage cells grow, swell and then die, to be replaced by living bone. Errors in bone development occur as a result of difficulty in getting blood supply into the cartilage growth areas.
Problems occur when bone growth is interrupted.
If the supply of vital nutrients via blood to the developing area is impaired, the growth process is compromised. Developmental Orthopedic Disease Developmental orthopedic disease of young, growing horses includes any disturbance in changing the cartilaginous precursor of the skeleton to functional bone. Six distinct disease entities fall under the general term developmental orthopedic disease. Occur as a result in failed endochondral ossification. The conversion of cartilage into bone starts in the developing fetus and continues following birth and through maturity.