Anatomy of the cervicothoracic junction: A study of cadaveric dissection, cryomicrotomy, and magnetic resonance imaging

The morphologic characteristics of the cervicothoracic junction from C6 to T2 were examined. Gross dissection and cryomicrotomy was performed on 13 fr esh cadavers. Four healthy volunteers underwent magnetic resonance imaging. Results indicated that vertebral body dimensions do not change appreciably , except for vertebral body heights and medial pedicular angulation, both o f which. increase from C6 to T2. Based on the findings of gross dissection anal cryomicrotomy, the mediolateral width of the spinal canal was largest at C6 to accommodate the larger spinal cord at C6. The cross-sectional area ratios of the spinal cord to spinal canal were 1:2.3 at C6, 1:3.7 at C7, 1 :4 at T1, and 1:3.7 at T2. The foraminal height and width were greater at C 7-T1 and T1-T2 than at C6-C7. The thinnest lamina was at C7. The anatomy of the pedicles showed that the outer mediolateral diameter averaged 6.78 mm at C6, 7.5 mm at C7, 9.23 mm at T1, and 7.9 mm at T2. The superior-inferior diameter of the pedicle increased from 7.58 mm at C6 to 12.43 mm at T2. Me dial angulations decreased from 44.5 at C6 to 23.35 at T2. The coronal angu lation of the exiting nerve was 64.83 for C7, 79.83 for C8, and 90.33 for T 1 nerve roots based on coronal magnetic resonance imaging. Finally, gross d issection during the anterior approach to the cervicothoracic junction reve aled that this approach was extensible, allowing access to the anterior asp ect of the cervicothoracic spine. Associated vital structures must be prote cted, such as the arch of aorta, common carotid artery, innominate vein, th oracic duct, recurrent laryngeal nerve, stellate ganglion, trachea, and eso phagus.