ABSTRACT
<p><b>OBJECTIVE</b>To measure important parameters of anterior internal fixation for the cervicothoracic junction by us-ing imaging measurement, and provide reference for cervicothoracic junction surgery and design of steel plate screw internal fixation.</p><p><b>METHODS</b>From June to November 2012, 120 health people's median sagittal plane MRI of cervical spine were ran-domly collected. Of the 120 cases, there were 58 males and 62 females with an average age of 48.3 +/- 13.7, ranging the age of 20 to 78 years old. The anterior,middle and posterior height of vertebral, anterior, upper, medium and lower sagittal diameter, an-terior height of different segments and Cobb angle were measured by measuring machine in the PACS system.</p><p><b>RESULTS</b>The an-terior, middle and posterior height of vertebral, medium and lower sagittal diameter gradually increased from cranial to caudal of cervicothoracic junction (P < 0.01). For single vertebral,posterior> anterior>middle height (P < 0.01), lower > upper>medium sagittal diameter (P < 0.01). The lower sagittal diameter of upper vertebral body was close to upper sagittal diameter of lower vertebral body. Cobb angle of male was (7.61 +/- 3.85) degrees, while female's was (5.58 +/- 2.59) degrees .</p><p><b>CONCLUSION</b>During the anterior in-ternal fixation of cervicothoracic junction, it is suggested that the entry points of upper vertebral body should locate on the lower and middle 1/3 of vertebral body, and screws could slightly incline towards cranial,the entry points of lower vertebral body should locate on the upper and middle 1/3 of vertebral body, while screws could slightly incline towards caudal, also can be prebent according to Cobb angle of health.</p>