The most important target organ for linear growth is the epiphyseal growth plate, a layer of cartilage found in growing long bones between the epiphysis and the metaphysis. Longitudinal bone growth occurs at the growth plate by endochondral ossification, in which cartilage is formed and then remodeled into bone tissue (77). The cellular distribution is organised according to the stage of cell maturation and differentiation, under a tightly controlled programme, and consists of the following cell layers: germinative, proliferative, hypertrophic and degenerative (78). The germinative cell layer or resting zone consists of the stem cells that enter the proliferative cell layer organised in column following the longitudinal axis of the bone. The proliferative layer is crucial in endochondral bone formation, when the chondrocyte divides, the resulting two cells line up along the bone axis and as this process continues all columns are organised along this axis. It is unclear which factor or factors determine this important spatial orientation. Once cell division ceases these mature cells form part of the hypertrophic cell layer (79) and the final layer, the calcifying zone is where cartilaginous matrix is transformed into bone matrix.