Wolff's law states that:

Wolff's law.- it states that by progressive bone deposition on to one surface (to compression site) and resorption from other (tension site), it is responsible for the gross changes in the shape of bones which occur during development and adaptation of bone to applied loads It refers to over all consequences for the whole bone of the sum of all the units of remodelling activity which are occurring throughout the bone. It has usually predominant osteoclastic activity at tension site and osteoblastic activity at compression site.