Growing a Bone Requires Foresight

Picture a linear bone growing. Say it's a leg bone, with attachment points for muscles and tendons along its length. Picture one such protrusion located a third of the way from one end. If the bone grows only at one end, the protuberance will migrate from its 1/3 position, causing problems for the tissues that need to attach there. If the bone grows at both ends, the same problem can occur.

How does the bone "know" to keep its structures at proper ratios along its length as it grows? That p...