Surface Anatomical Landmark and Optimal Insertion Angle in Cervical Epidural Block

Objective: The aim of this study is to evaluate the surface anatomical landmark for the cervical epidural block by investigating the proportion of patient's prominence in the 7th cervical vertebra. And the most optimal insertion angle over the mid point between the 6th and the 7th cervical spinous process is also measured. Method: Patients who did a plane x-ray examination of cervical spine were selected. We performed plane x-ray after marking on cervical vertebra prominence that was assumed as the spinous process of the 7th cervical vertebra by inspection and palpation. We identified where the marker were located on the spinous process. Moreover, we measured optimal insertion angle in the plane x-ray of cervical spine lateral. Results: A total 100 cases were identified. The vertebra prominence was on the 7th cervical vertebra in 62 cases and the 6th cervical vertebra in 29 cases. The 1st thoracic vertebra was in the 2 cases and the 6th and 7th cervical vertebra in the 7 cases. Conclusion: The vertebra prominence was identified as the spinous process of the 7th cervical vertebra in sixty two percent of the cases. And the most optimal insertion angle is a -25.28 degree angle from the perpendicular line of the skin. (J Korean Acad Rehab Med 2006; 30: 169-172)