As the older chondrocytes degenerate, osteoblasts ossify the remains to form new bone. The tibial cartilage does not mature enough to ossify (turn into bone). In old age, cranial sutures may ossify (turn to bone) completely. This cartilage may ossify with age. The hamate does not fully ossify until about the 15th year of life. It is the last carpal bone to ossify.