MadSci Network: Medicine |
Hi Peter, Body growth, hence final height, is determined largely by the growth in length of the long bones. At birth, the ends of most long bones still consist of cartilage. Gradually, these begin to ossify, but a plate of growing cartilage remains at the bone ends. This is called the epiphysial, or growth, plate, and continues to produce new cartilage, which increases the length of the bone, before this too ossifies. At the end of the growing period, division of cartilage cells within the plate ceases, and the plate itself ossifies, and normal bone growth stops. The rate and duration of growth is determined by many factors - genetic, nutritional, and hormonal, and it should come as no surprise that there is a growth spurt around puberty, when many of the responsible hormones are very active. Growth then tails off dramatically after puberty, and ceases around the late teens to early twenties. Over the last ten years or so, artificial stretching of long bones has been increasingly used where one or both limbs are abnormally short. This involves breaking the bone and attaching the fragments to special steel rods which can be lengthened bit by bit. I would imagine that this is a painful and difficult process, but has a good success rate. Best wishes, Doc C-P.
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