Specific birth defects which can occur, but certainly are not limited to the following list, may include such congenital anomalies of spine (or vertebral anomalies) as fused ribs, or missing vertebrae, particularly in the spinal region. Some patients that have fused ribs must undergo replacement of the ribs with titanium ribs, if their ribcages do not grow with the rest of the body. The titanium ribs may have to be replaced multiple times throughout a patient’s lifetime. If the lower few vertebrae, known also as the sacrum, are missing, it generally causes no ill affect on the patient.