1.Applied Anatomy Of The Anterior Approach To The Cervicothoracic Junction Of The Spinal Column 2.Applied Anatomy Of The Lower Cervical Pedicle Screw Insertion

[Abstract] Objective To explore an optimal method of exposing thecervicothoracic junction(T1-T3) . Methods The anatomic relationship between the cervicothoracic junction and the adjacent tissue were observed on 30 adult embalmed cadavers (50 sides) by modeling the anterior approach to the cervicothoracic junction. T1-T3 vertebra can be exposed through dissecting a safe space among superior edge of the aortic arch, left subclavian artery, left common carotid, brachiocephalic trunk, left brachiocephalic vein and right brachiocephalic vein. Results A standard cervical left approach was combined with osteotomy of the clavicle and partial median sternotomy, which transverse osteotomy through the synostosis between the manubrium and body of the sternum, is the best optimal selection of exposing anterior aspect of the T1-T3 vertebra in all anterior approaches. A safe space can be dissected through this operational method: left carotid sheath (common carotid, internal jugular vein, vagus nerve and its branches), thoracic duct, truncus sympathicus cervicalis, and left pleura mediastinalis were pulled towards lateral; trachea, esophagus, and left recurrent laryngeal nerve were pulled towards internal; left brachiocephalic vein was pulled towards inferior. The results of a study on 30 adult human cadavers showed that the anterior aspect of T1-T3 can be easily exposed through such the anterior approach to the cervicothoracic spinal junction. Conclusions Adequate exposure of the low cervical to the upper thoracic spine can be obtained with this approach. It provides adequate work room for inserting the screw into T1 and T3 vertebra. [Abstract] Objective To explore an accurate method of pedicle screw insertion in cervical vertebra(C₃-C₇) . Methods Anatomic morphology of lateral mass and pedicle, and their anatomic relationship with the adjacent were observed on C₃-C₇ segment of 25 adult embalmed cadavers (50 sides). Results l)The inferior edge of the base of the posterior tubercle of the transverse process and the inferior edge of the pedicle were connected with each other on 25 adult embalmed cadaver (50 sides); The transverse section which passed through the median point between the superior edge and the inferior edge of the base of the posterior tubercle of the transverse process, and the transverse section which passed through the central axis between the superior edge and the inferior edge of the pedicle were in the same of horizontal plane. The superior and inferior position of the pedicle insertion was determined by this transverse section which passed through the median point between the superior and the inferior edge of the base of the posterior tubercle of the transverse process; 2) There was an internal-descending "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process. The wall of the triangular sulcule: the anterior wall was the base of the posterior tubercle of the transverse process; the posterior wall was the anterolateral edge of the inferior articular process; the bottom of the sulcule was connected with the interior edge of the pedicle. The vertical length between the top of triangle and the planes of inferior edge of the pedicle was (2．78±1．71) mm. The inferior edge of the cervical pedicle could be detected by a blunt touch needle along the "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process in surgical operation. 3) The lateral fovea of the articular process was observed on all lateral mass (50 sides). The relation of the medial and lateral position was the lateral edge of the lateral fovea of the articular process. The horizontal length between the lateral fovea of the articular process and the point of pedicle screw insertion was (3．14±1．45) mm. 4) The diameter of pedicle screw, about (2．78±1．71) mm, was the transverse diameter of the cancellous bone of the narrow part of the cervical pedicle.. Conclusions The median point between the superior edge and the inferior edge of the base of the posterior tubercle of the transverse process, the lateral fovea of the articular process, and the triangular sulcule between the base of the posterior tubercle of the transverse process and the anterolateral edge of inferior articular process, were easy to be exposed and identified in the surgical operation. Transpedicular screw can be precisely inserted through this method. The first and third points aforesaid in results were the first time reported.