Postnatal Development of the Thoracic Spine

STUDY DESIGN: Forty-two thoracic spines ranging from neonate to 15 years of age were studied. OBJECTIVES: Postnatal development of the thoracic vertebrae and their component elements were cataloged. SUMMARY OF BACKGROUND DATA: This study was part of an ongoing series concerning the progressive morphologic development of the human postnatal skeleton. METHODS: The spines were studied morphologically and radiologically. RESULTS: Fusion of the thoracic spine neurocentral synchondroses occurs in a cranial to caudal direction in humans by 6 to 7 years of age. The transverse processes exhibit a progressive posterior and inferior angulation with age and moving down the thoracic spine. The facet joints angulate accordingly. The spinous processes elongate and increasingly angulate with age, especially in the mid-thoracic region. The relative contribution of the posterior elements, compared with the centrum, to the growth of the vertebral body progressively decreases moving down thoracic spine. CONCLUSION: This study demonstrated areas of anatomic change that undoubtedly play a role in normal and abnormal spine development.