Figure 10. The different endoscopic approach options in the cervical spine. As can be seen, both are described, anterior and posterior. a: endoscopic anterior cervical approach; b: endoscopic posterior cervical approach, single-portal ipsilateral / foraminal; c: endoscopic posterior cervical approach, single-portal bilateral; 1: endoscopic anterior cervical approach; 2: single- or two-portal unilateral; 3: single- or two-portal bilateral.