31. Advanced and final stages of development are characterized by metaplastic ossification , as discussed above. 32. One key adaptation is the fusing of bones into single ossifications , such as the pygostyle. 33. Calcification is often confused with ossification . 34. Occasionally there can be peculiar complete or partial absence of ossification in one or more vertebrae. 35. Bone is resorbed by osteoclasts, and is deposited by osteoblasts in a process called ossification . 36. In a fracture that is rigidly immobilized the fracture heals by the process of intramembranous ossification . 37. It is characterized by spiny ankylosis and enthesopathy ( ossification of the ligaments and entheses ). 38. It is a process that occurs during ossification , but not " vice versa ". 39. UAP is caused by a separation from the ulna of the ossification center of the anconeal process. 40. This effect may be useful and etidronate is in fact used this way to fight heterotopic ossification .
